linux/fs/btrfs/tree-log.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2008 Oracle. All rights reserved.
*/
#include <linux/sched.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/blkdev.h>
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
#include <linux/list_sort.h>
#include <linux/iversion.h>
#include "misc.h"
btrfs: Remove custom crc32c init code The custom crc32 init code was introduced in 14a958e678cd ("Btrfs: fix btrfs boot when compiled as built-in") to enable using btrfs as a built-in. However, later as pointed out by 60efa5eb2e88 ("Btrfs: use late_initcall instead of module_init") this wasn't enough and finally btrfs was switched to late_initcall which comes after the generic crc32c implementation is initiliased. The latter commit superseeded the former. Now that we don't have to maintain our own code let's just remove it and switch to using the generic implementation. Despite touching a lot of files the patch is really simple. Here is the gist of the changes: 1. Select LIBCRC32C rather than the low-level modules. 2. s/btrfs_crc32c/crc32c/g 3. replace hash.h with linux/crc32c.h 4. Move the btrfs namehash funcs to ctree.h and change the tree accordingly. I've tested this with btrfs being both a module and a built-in and xfstest doesn't complain. Does seem to fix the longstanding problem of not automatically selectiong the crc32c module when btrfs is used. Possibly there is a workaround in dracut. The modinfo confirms that now all the module dependencies are there: before: depends: zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate after: depends: libcrc32c,zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add more info to changelog from mails ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-08 09:45:05 +00:00
#include "ctree.h"
#include "tree-log.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "backref.h"
#include "compression.h"
#include "qgroup.h"
#include "inode-map.h"
/* magic values for the inode_only field in btrfs_log_inode:
*
* LOG_INODE_ALL means to log everything
* LOG_INODE_EXISTS means to log just enough to recreate the inode
* during log replay
*/
enum {
LOG_INODE_ALL,
LOG_INODE_EXISTS,
LOG_OTHER_INODE,
LOG_OTHER_INODE_ALL,
};
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* directory trouble cases
*
* 1) on rename or unlink, if the inode being unlinked isn't in the fsync
* log, we must force a full commit before doing an fsync of the directory
* where the unlink was done.
* ---> record transid of last unlink/rename per directory
*
* mkdir foo/some_dir
* normal commit
* rename foo/some_dir foo2/some_dir
* mkdir foo/some_dir
* fsync foo/some_dir/some_file
*
* The fsync above will unlink the original some_dir without recording
* it in its new location (foo2). After a crash, some_dir will be gone
* unless the fsync of some_file forces a full commit
*
* 2) we must log any new names for any file or dir that is in the fsync
* log. ---> check inode while renaming/linking.
*
* 2a) we must log any new names for any file or dir during rename
* when the directory they are being removed from was logged.
* ---> check inode and old parent dir during rename
*
* 2a is actually the more important variant. With the extra logging
* a crash might unlink the old name without recreating the new one
*
* 3) after a crash, we must go through any directories with a link count
* of zero and redo the rm -rf
*
* mkdir f1/foo
* normal commit
* rm -rf f1/foo
* fsync(f1)
*
* The directory f1 was fully removed from the FS, but fsync was never
* called on f1, only its parent dir. After a crash the rm -rf must
* be replayed. This must be able to recurse down the entire
* directory tree. The inode link count fixup code takes care of the
* ugly details.
*/
/*
* stages for the tree walking. The first
* stage (0) is to only pin down the blocks we find
* the second stage (1) is to make sure that all the inodes
* we find in the log are created in the subvolume.
*
* The last stage is to deal with directories and links and extents
* and all the other fun semantics
*/
enum {
LOG_WALK_PIN_ONLY,
LOG_WALK_REPLAY_INODES,
LOG_WALK_REPLAY_DIR_INDEX,
LOG_WALK_REPLAY_ALL,
};
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
int inode_only,
const loff_t start,
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
const loff_t end,
struct btrfs_log_ctx *ctx);
static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all);
/*
* tree logging is a special write ahead log used to make sure that
* fsyncs and O_SYNCs can happen without doing full tree commits.
*
* Full tree commits are expensive because they require commonly
* modified blocks to be recowed, creating many dirty pages in the
* extent tree an 4x-6x higher write load than ext3.
*
* Instead of doing a tree commit on every fsync, we use the
* key ranges and transaction ids to find items for a given file or directory
* that have changed in this transaction. Those items are copied into
* a special tree (one per subvolume root), that tree is written to disk
* and then the fsync is considered complete.
*
* After a crash, items are copied out of the log-tree back into the
* subvolume tree. Any file data extents found are recorded in the extent
* allocation tree, and the log-tree freed.
*
* The log tree is read three times, once to pin down all the extents it is
* using in ram and once, once to create all the inodes logged in the tree
* and once to do all the other items.
*/
/*
* start a sub transaction and setup the log tree
* this increments the log tree writer count to make the people
* syncing the tree wait for us to finish
*/
static int start_log_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
mutex_lock(&root->log_mutex);
if (root->log_root) {
if (btrfs_need_log_full_commit(trans)) {
ret = -EAGAIN;
goto out;
}
if (!root->log_start_pid) {
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
} else if (root->log_start_pid != current->pid) {
set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
}
} else {
mutex_lock(&fs_info->tree_log_mutex);
if (!fs_info->log_root_tree)
ret = btrfs_init_log_root_tree(trans, fs_info);
mutex_unlock(&fs_info->tree_log_mutex);
if (ret)
goto out;
ret = btrfs_add_log_tree(trans, root);
if (ret)
goto out;
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
}
atomic_inc(&root->log_batch);
atomic_inc(&root->log_writers);
if (ctx) {
int index = root->log_transid % 2;
list_add_tail(&ctx->list, &root->log_ctxs[index]);
ctx->log_transid = root->log_transid;
}
out:
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* returns 0 if there was a log transaction running and we were able
* to join, or returns -ENOENT if there were not transactions
* in progress
*/
static int join_running_log_trans(struct btrfs_root *root)
{
int ret = -ENOENT;
mutex_lock(&root->log_mutex);
if (root->log_root) {
ret = 0;
atomic_inc(&root->log_writers);
}
mutex_unlock(&root->log_mutex);
return ret;
}
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* This either makes the current running log transaction wait
* until you call btrfs_end_log_trans() or it makes any future
* log transactions wait until you call btrfs_end_log_trans()
*/
void btrfs_pin_log_trans(struct btrfs_root *root)
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
{
mutex_lock(&root->log_mutex);
atomic_inc(&root->log_writers);
mutex_unlock(&root->log_mutex);
}
/*
* indicate we're done making changes to the log tree
* and wake up anyone waiting to do a sync
*/
void btrfs_end_log_trans(struct btrfs_root *root)
{
if (atomic_dec_and_test(&root->log_writers)) {
/* atomic_dec_and_test implies a barrier */
cond_wake_up_nomb(&root->log_writer_wait);
}
}
static int btrfs_write_tree_block(struct extent_buffer *buf)
{
return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
buf->start + buf->len - 1);
}
static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
{
filemap_fdatawait_range(buf->pages[0]->mapping,
buf->start, buf->start + buf->len - 1);
}
/*
* the walk control struct is used to pass state down the chain when
* processing the log tree. The stage field tells us which part
* of the log tree processing we are currently doing. The others
* are state fields used for that specific part
*/
struct walk_control {
/* should we free the extent on disk when done? This is used
* at transaction commit time while freeing a log tree
*/
int free;
/* should we write out the extent buffer? This is used
* while flushing the log tree to disk during a sync
*/
int write;
/* should we wait for the extent buffer io to finish? Also used
* while flushing the log tree to disk for a sync
*/
int wait;
/* pin only walk, we record which extents on disk belong to the
* log trees
*/
int pin;
/* what stage of the replay code we're currently in */
int stage;
Btrfs: fix warning when replaying log after fsync of a tmpfile When replaying a log which contains a tmpfile (which necessarily has a link count of 0) we end up calling inc_nlink(), at fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like the following: [195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40 [195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1 [195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [195191.943726] RIP: 0010:inc_nlink+0x33/0x40 [195191.943728] RSP: 0018:ffffb96e425e3870 EFLAGS: 00010246 [195191.943730] RAX: 0000000000000000 RBX: ffff8c0d1e6af4f0 RCX: 0000000000000006 [195191.943731] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8c0d1e6af4f0 [195191.943731] RBP: 0000000000000097 R08: 0000000000000001 R09: 0000000000000000 [195191.943732] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb96e425e3a60 [195191.943733] R13: ffff8c0d10cff0c8 R14: ffff8c0d0d515348 R15: ffff8c0d78a1b3f8 [195191.943735] FS: 00007f570ee24480(0000) GS:ffff8c0dfb200000(0000) knlGS:0000000000000000 [195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [195191.943737] CR2: 00005593286277c8 CR3: 00000000bb8f2006 CR4: 00000000003606f0 [195191.943739] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [195191.943740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [195191.943741] Call Trace: [195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs] [195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs] [195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943825] walk_log_tree+0xae/0x1d0 [btrfs] [195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs] [195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs] [195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs] [195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs] [195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943899] ? pcpu_alloc+0x55b/0x7c0 [195191.943906] ? mount_fs+0x3b/0x140 [195191.943908] mount_fs+0x3b/0x140 [195191.943912] ? __init_waitqueue_head+0x36/0x50 [195191.943916] vfs_kern_mount+0x62/0x160 [195191.943927] btrfs_mount+0x134/0x890 [btrfs] [195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943938] ? pcpu_alloc+0x55b/0x7c0 [195191.943943] ? mount_fs+0x3b/0x140 [195191.943952] ? btrfs_remount+0x570/0x570 [btrfs] [195191.943954] mount_fs+0x3b/0x140 [195191.943956] ? __init_waitqueue_head+0x36/0x50 [195191.943960] vfs_kern_mount+0x62/0x160 [195191.943963] do_mount+0x1f9/0xd40 [195191.943967] ? memdup_user+0x4b/0x70 [195191.943971] ksys_mount+0x7e/0xd0 [195191.943974] __x64_sys_mount+0x21/0x30 [195191.943977] do_syscall_64+0x60/0x1b0 [195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe [195191.943983] RIP: 0033:0x7f570e4e524a [195191.943986] RSP: 002b:00007ffd83589478 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [195191.943989] RAX: ffffffffffffffda RBX: 0000563f335b2060 RCX: 00007f570e4e524a [195191.943990] RDX: 0000563f335b2240 RSI: 0000563f335b2280 RDI: 0000563f335b2260 [195191.943992] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020 [195191.943993] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000563f335b2260 [195191.943994] R13: 0000563f335b2240 R14: 0000000000000000 R15: 00000000ffffffff [195191.944002] irq event stamp: 8688 [195191.944010] hardirqs last enabled at (8687): [<ffffffff9cb004c3>] console_unlock+0x503/0x640 [195191.944012] hardirqs last disabled at (8688): [<ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c [195191.944018] softirqs last enabled at (8638): [<ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150 [195191.944020] softirqs last disabled at (8634): [<ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60 [195191.944022] ---[ end trace 5d6e873a9a0b811a ]--- This happens because the inode does not have the flag I_LINKABLE set, which is a runtime only flag, not meant to be persisted, set when the inode is created through open(2) if the flag O_EXCL is not passed to it. Except for the warning, there are no other consequences (like corruptions or metadata inconsistencies). Since it's pointless to replay a tmpfile as it would be deleted in a later phase of the log replay procedure (it has a link count of 0), fix this by not logging tmpfiles and if a tmpfile is found in a log (created by a kernel without this change), skip the replay of the inode. A test case for fstests follows soon. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.18+ Reported-by: Martin Steigerwald <martin@lichtvoll.de> Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-08 10:12:55 +00:00
/*
* Ignore any items from the inode currently being processed. Needs
* to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
* the LOG_WALK_REPLAY_INODES stage.
*/
bool ignore_cur_inode;
/* the root we are currently replaying */
struct btrfs_root *replay_dest;
/* the trans handle for the current replay */
struct btrfs_trans_handle *trans;
/* the function that gets used to process blocks we find in the
* tree. Note the extent_buffer might not be up to date when it is
* passed in, and it must be checked or read if you need the data
* inside it
*/
int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level);
};
/*
* process_func used to pin down extents, write them or wait on them
*/
static int process_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
/*
* If this fs is mixed then we need to be able to process the leaves to
* pin down any logged extents, so we have to read the block.
*/
if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
ret = btrfs_read_buffer(eb, gen, level, NULL);
if (ret)
return ret;
}
if (wc->pin)
ret = btrfs_pin_extent_for_log_replay(fs_info, eb->start,
eb->len);
if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
if (wc->pin && btrfs_header_level(eb) == 0)
ret = btrfs_exclude_logged_extents(eb);
if (wc->write)
btrfs_write_tree_block(eb);
if (wc->wait)
btrfs_wait_tree_block_writeback(eb);
}
return ret;
}
/*
* Item overwrite used by replay and tree logging. eb, slot and key all refer
* to the src data we are copying out.
*
* root is the tree we are copying into, and path is a scratch
* path for use in this function (it should be released on entry and
* will be released on exit).
*
* If the key is already in the destination tree the existing item is
* overwritten. If the existing item isn't big enough, it is extended.
* If it is too large, it is truncated.
*
* If the key isn't in the destination yet, a new item is inserted.
*/
static noinline int overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
u32 item_size;
u64 saved_i_size = 0;
int save_old_i_size = 0;
unsigned long src_ptr;
unsigned long dst_ptr;
int overwrite_root = 0;
bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
overwrite_root = 1;
item_size = btrfs_item_size_nr(eb, slot);
src_ptr = btrfs_item_ptr_offset(eb, slot);
/* look for the key in the destination tree */
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
return ret;
if (ret == 0) {
char *src_copy;
char *dst_copy;
u32 dst_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
if (dst_size != item_size)
goto insert;
if (item_size == 0) {
btrfs_release_path(path);
return 0;
}
dst_copy = kmalloc(item_size, GFP_NOFS);
src_copy = kmalloc(item_size, GFP_NOFS);
if (!dst_copy || !src_copy) {
btrfs_release_path(path);
kfree(dst_copy);
kfree(src_copy);
return -ENOMEM;
}
read_extent_buffer(eb, src_copy, src_ptr, item_size);
dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
item_size);
ret = memcmp(dst_copy, src_copy, item_size);
kfree(dst_copy);
kfree(src_copy);
/*
* they have the same contents, just return, this saves
* us from cowing blocks in the destination tree and doing
* extra writes that may not have been done by a previous
* sync
*/
if (ret == 0) {
btrfs_release_path(path);
return 0;
}
/*
* We need to load the old nbytes into the inode so when we
* replay the extents we've logged we get the right nbytes.
*/
if (inode_item) {
struct btrfs_inode_item *item;
u64 nbytes;
u32 mode;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
nbytes = btrfs_inode_nbytes(path->nodes[0], item);
item = btrfs_item_ptr(eb, slot,
struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, nbytes);
/*
* If this is a directory we need to reset the i_size to
* 0 so that we can set it up properly when replaying
* the rest of the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
} else if (inode_item) {
struct btrfs_inode_item *item;
u32 mode;
/*
* New inode, set nbytes to 0 so that the nbytes comes out
* properly when we replay the extents.
*/
item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, 0);
/*
* If this is a directory we need to reset the i_size to 0 so
* that we can set it up properly when replaying the rest of
* the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
insert:
btrfs_release_path(path);
/* try to insert the key into the destination tree */
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
path->skip_release_on_error = 1;
ret = btrfs_insert_empty_item(trans, root, path,
key, item_size);
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
path->skip_release_on_error = 0;
/* make sure any existing item is the correct size */
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
if (ret == -EEXIST || ret == -EOVERFLOW) {
u32 found_size;
found_size = btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
if (found_size > item_size)
btrfs_truncate_item(path, item_size, 1);
else if (found_size < item_size)
btrfs_extend_item(path, item_size - found_size);
} else if (ret) {
return ret;
}
dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
/* don't overwrite an existing inode if the generation number
* was logged as zero. This is done when the tree logging code
* is just logging an inode to make sure it exists after recovery.
*
* Also, don't overwrite i_size on directories during replay.
* log replay inserts and removes directory items based on the
* state of the tree found in the subvolume, and i_size is modified
* as it goes
*/
if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
struct btrfs_inode_item *src_item;
struct btrfs_inode_item *dst_item;
src_item = (struct btrfs_inode_item *)src_ptr;
dst_item = (struct btrfs_inode_item *)dst_ptr;
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
if (btrfs_inode_generation(eb, src_item) == 0) {
struct extent_buffer *dst_eb = path->nodes[0];
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
const u64 ino_size = btrfs_inode_size(eb, src_item);
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
/*
* For regular files an ino_size == 0 is used only when
* logging that an inode exists, as part of a directory
* fsync, and the inode wasn't fsynced before. In this
* case don't set the size of the inode in the fs/subvol
* tree, otherwise we would be throwing valid data away.
*/
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
ino_size != 0) {
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
struct btrfs_map_token token;
btrfs_init_map_token(&token, dst_eb);
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
btrfs_set_token_inode_size(dst_eb, dst_item,
ino_size, &token);
}
goto no_copy;
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
}
if (overwrite_root &&
S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
save_old_i_size = 1;
saved_i_size = btrfs_inode_size(path->nodes[0],
dst_item);
}
}
copy_extent_buffer(path->nodes[0], eb, dst_ptr,
src_ptr, item_size);
if (save_old_i_size) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
}
/* make sure the generation is filled in */
if (key->type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
btrfs_set_inode_generation(path->nodes[0], dst_item,
trans->transid);
}
}
no_copy:
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
/*
* simple helper to read an inode off the disk from a given root
* This can only be called for subvolume roots and not for the log
*/
static noinline struct inode *read_one_inode(struct btrfs_root *root,
u64 objectid)
{
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
struct btrfs_key key;
struct inode *inode;
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
key.objectid = objectid;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
Btrfs: change how we mount subvolumes This work is in preperation for being able to set a different root as the default mounting root. There is currently a problem with how we mount subvolumes. We cannot currently mount a subvolume of a subvolume, you can only mount subvolumes/snapshots of the default subvolume. So say you take a snapshot of the default subvolume and call it snap1, and then take a snapshot of snap1 and call it snap2, so now you have / /snap1 /snap1/snap2 as your available volumes. Currently you can only mount / and /snap1, you cannot mount /snap1/snap2. To fix this problem instead of passing subvolid=<name> you must pass in subvolid=<treeid>, where <treeid> is the tree id that gets spit out via the subvolume listing you get from the subvolume listing patches (btrfs filesystem list). This allows us to mount /, /snap1 and /snap1/snap2 as the root volume. In addition to the above, we also now read the default dir item in the tree root to get the root key that it points to. For now this just points at what has always been the default subvolme, but later on I plan to change it to point at whatever root you want to be the new default root, so you can just set the default mount and not have to mount with -o subvolid=<treeid>. I tested this out with the above scenario and it worked perfectly. Thanks, mount -o subvol operates inside the selected subvolid. For example: mount -o subvol=snap1,subvolid=256 /dev/xxx /mnt /mnt will have the snap1 directory for the subvolume with id 256. mount -o subvol=snap /dev/xxx /mnt /mnt will be the snap directory of whatever the default subvolume is. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-04 17:38:27 +00:00
inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
if (IS_ERR(inode))
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
inode = NULL;
return inode;
}
/* replays a single extent in 'eb' at 'slot' with 'key' into the
* subvolume 'root'. path is released on entry and should be released
* on exit.
*
* extents in the log tree have not been allocated out of the extent
* tree yet. So, this completes the allocation, taking a reference
* as required if the extent already exists or creating a new extent
* if it isn't in the extent allocation tree yet.
*
* The extent is inserted into the file, dropping any existing extents
* from the file that overlap the new one.
*/
static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int found_type;
u64 extent_end;
u64 start = key->offset;
u64 nbytes = 0;
struct btrfs_file_extent_item *item;
struct inode *inode = NULL;
unsigned long size;
int ret = 0;
item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
nbytes = btrfs_file_extent_num_bytes(eb, item);
extent_end = start + nbytes;
/*
* We don't add to the inodes nbytes if we are prealloc or a
* hole.
*/
if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
nbytes = 0;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size = btrfs_file_extent_ram_bytes(eb, item);
nbytes = btrfs_file_extent_ram_bytes(eb, item);
extent_end = ALIGN(start + size,
fs_info->sectorsize);
} else {
ret = 0;
goto out;
}
inode = read_one_inode(root, key->objectid);
if (!inode) {
ret = -EIO;
goto out;
}
/*
* first check to see if we already have this extent in the
* file. This must be done before the btrfs_drop_extents run
* so we don't try to drop this extent.
*/
ret = btrfs_lookup_file_extent(trans, root, path,
btrfs_ino(BTRFS_I(inode)), start, 0);
if (ret == 0 &&
(found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
struct btrfs_file_extent_item cmp1;
struct btrfs_file_extent_item cmp2;
struct btrfs_file_extent_item *existing;
struct extent_buffer *leaf;
leaf = path->nodes[0];
existing = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
read_extent_buffer(eb, &cmp1, (unsigned long)item,
sizeof(cmp1));
read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
sizeof(cmp2));
/*
* we already have a pointer to this exact extent,
* we don't have to do anything
*/
if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
btrfs_release_path(path);
goto out;
}
}
btrfs_release_path(path);
/* drop any overlapping extents */
ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1);
if (ret)
goto out;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
u64 offset;
unsigned long dest_offset;
struct btrfs_key ins;
if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
btrfs_fs_incompat(fs_info, NO_HOLES))
goto update_inode;
ret = btrfs_insert_empty_item(trans, root, path, key,
sizeof(*item));
if (ret)
goto out;
dest_offset = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
copy_extent_buffer(path->nodes[0], eb, dest_offset,
(unsigned long)item, sizeof(*item));
ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
ins.type = BTRFS_EXTENT_ITEM_KEY;
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
offset = key->offset - btrfs_file_extent_offset(eb, item);
/*
* Manually record dirty extent, as here we did a shallow
* file extent item copy and skip normal backref update,
* but modifying extent tree all by ourselves.
* So need to manually record dirty extent for qgroup,
* as the owner of the file extent changed from log tree
* (doesn't affect qgroup) to fs/file tree(affects qgroup)
*/
ret = btrfs_qgroup_trace_extent(trans,
btrfs_file_extent_disk_bytenr(eb, item),
btrfs_file_extent_disk_num_bytes(eb, item),
GFP_NOFS);
if (ret < 0)
goto out;
if (ins.objectid > 0) {
struct btrfs_ref ref = { 0 };
u64 csum_start;
u64 csum_end;
LIST_HEAD(ordered_sums);
/*
* is this extent already allocated in the extent
* allocation tree? If so, just add a reference
*/
ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
ins.offset);
if (ret == 0) {
btrfs_init_generic_ref(&ref,
BTRFS_ADD_DELAYED_REF,
ins.objectid, ins.offset, 0);
btrfs_init_data_ref(&ref,
root->root_key.objectid,
Btrfs: fix regression running delayed references when using qgroups In the kernel 4.2 merge window we had a big changes to the implementation of delayed references and qgroups which made the no_quota field of delayed references not used anymore. More specifically the no_quota field is not used anymore as of: commit 0ed4792af0e8 ("btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.") Leaving the no_quota field actually prevents delayed references from getting merged, which in turn cause the following BUG_ON(), at fs/btrfs/extent-tree.c, to be hit when qgroups are enabled: static int run_delayed_tree_ref(...) { (...) BUG_ON(node->ref_mod != 1); (...) } This happens on a scenario like the following: 1) Ref1 bytenr X, action = BTRFS_ADD_DELAYED_REF, no_quota = 1, added. 2) Ref2 bytenr X, action = BTRFS_DROP_DELAYED_REF, no_quota = 0, added. It's not merged with Ref1 because Ref1->no_quota != Ref2->no_quota. 3) Ref3 bytenr X, action = BTRFS_ADD_DELAYED_REF, no_quota = 1, added. It's not merged with the reference at the tail of the list of refs for bytenr X because the reference at the tail, Ref2 is incompatible due to Ref2->no_quota != Ref3->no_quota. 4) Ref4 bytenr X, action = BTRFS_DROP_DELAYED_REF, no_quota = 0, added. It's not merged with the reference at the tail of the list of refs for bytenr X because the reference at the tail, Ref3 is incompatible due to Ref3->no_quota != Ref4->no_quota. 5) We run delayed references, trigger merging of delayed references, through __btrfs_run_delayed_refs() -> btrfs_merge_delayed_refs(). 6) Ref1 and Ref3 are merged as Ref1->no_quota = Ref3->no_quota and all other conditions are satisfied too. So Ref1 gets a ref_mod value of 2. 7) Ref2 and Ref4 are merged as Ref2->no_quota = Ref4->no_quota and all other conditions are satisfied too. So Ref2 gets a ref_mod value of 2. 8) Ref1 and Ref2 aren't merged, because they have different values for their no_quota field. 9) Delayed reference Ref1 is picked for running (select_delayed_ref() always prefers references with an action == BTRFS_ADD_DELAYED_REF). So run_delayed_tree_ref() is called for Ref1 which triggers the BUG_ON because Ref1->red_mod != 1 (equals 2). So fix this by removing the no_quota field, as it's not used anymore as of commit 0ed4792af0e8 ("btrfs: qgroup: Switch to new extent-oriented qgroup mechanism."). The use of no_quota was also buggy in at least two places: 1) At delayed-refs.c:btrfs_add_delayed_tree_ref() - we were setting no_quota to 0 instead of 1 when the following condition was true: is_fstree(ref_root) || !fs_info->quota_enabled 2) At extent-tree.c:__btrfs_inc_extent_ref() - we were attempting to reset a node's no_quota when the condition "!is_fstree(root_objectid) || !root->fs_info->quota_enabled" was true but we did it only in an unused local stack variable, that is, we never reset the no_quota value in the node itself. This fixes the remainder of problems several people have been having when running delayed references, mostly while a balance is running in parallel, on a 4.2+ kernel. Very special thanks to Stéphane Lesimple for helping debugging this issue and testing this fix on his multi terabyte filesystem (which took more than one day to balance alone, plus fsck, etc). Also, this fixes deadlock issue when using the clone ioctl with qgroups enabled, as reported by Elias Probst in the mailing list. The deadlock happens because after calling btrfs_insert_empty_item we have our path holding a write lock on a leaf of the fs/subvol tree and then before releasing the path we called check_ref() which did backref walking, when qgroups are enabled, and tried to read lock the same leaf. The trace for this case is the following: INFO: task systemd-nspawn:6095 blocked for more than 120 seconds. (...) Call Trace: [<ffffffff86999201>] schedule+0x74/0x83 [<ffffffff863ef64c>] btrfs_tree_read_lock+0xc0/0xea [<ffffffff86137ed7>] ? wait_woken+0x74/0x74 [<ffffffff8639f0a7>] btrfs_search_old_slot+0x51a/0x810 [<ffffffff863a129b>] btrfs_next_old_leaf+0xdf/0x3ce [<ffffffff86413a00>] ? ulist_add_merge+0x1b/0x127 [<ffffffff86411688>] __resolve_indirect_refs+0x62a/0x667 [<ffffffff863ef546>] ? btrfs_clear_lock_blocking_rw+0x78/0xbe [<ffffffff864122d3>] find_parent_nodes+0xaf3/0xfc6 [<ffffffff86412838>] __btrfs_find_all_roots+0x92/0xf0 [<ffffffff864128f2>] btrfs_find_all_roots+0x45/0x65 [<ffffffff8639a75b>] ? btrfs_get_tree_mod_seq+0x2b/0x88 [<ffffffff863e852e>] check_ref+0x64/0xc4 [<ffffffff863e9e01>] btrfs_clone+0x66e/0xb5d [<ffffffff863ea77f>] btrfs_ioctl_clone+0x48f/0x5bb [<ffffffff86048a68>] ? native_sched_clock+0x28/0x77 [<ffffffff863ed9b0>] btrfs_ioctl+0xabc/0x25cb (...) The problem goes away by eleminating check_ref(), which no longer is needed as its purpose was to get a value for the no_quota field of a delayed reference (this patch removes the no_quota field as mentioned earlier). Reported-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Tested-by: Stéphane Lesimple <stephane_btrfs@lesimple.fr> Reported-by: Elias Probst <mail@eliasprobst.eu> Reported-by: Peter Becker <floyd.net@gmail.com> Reported-by: Malte Schröder <malte@tnxip.de> Reported-by: Derek Dongray <derek@valedon.co.uk> Reported-by: Erkki Seppala <flux-btrfs@inside.org> Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
2015-10-23 06:52:54 +00:00
key->objectid, offset);
ret = btrfs_inc_extent_ref(trans, &ref);
if (ret)
goto out;
} else {
/*
* insert the extent pointer in the extent
* allocation tree
*/
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
ret = btrfs_alloc_logged_file_extent(trans,
root->root_key.objectid,
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
key->objectid, offset, &ins);
if (ret)
goto out;
}
btrfs_release_path(path);
if (btrfs_file_extent_compression(eb, item)) {
csum_start = ins.objectid;
csum_end = csum_start + ins.offset;
} else {
csum_start = ins.objectid +
btrfs_file_extent_offset(eb, item);
csum_end = csum_start +
btrfs_file_extent_num_bytes(eb, item);
}
ret = btrfs_lookup_csums_range(root->log_root,
csum_start, csum_end - 1,
&ordered_sums, 0);
if (ret)
goto out;
Btrfs: fix file read corruption after extent cloning and fsync If we partially clone one extent of a file into a lower offset of the file, fsync the file, power fail and then mount the fs to trigger log replay, we can get multiple checksum items in the csum tree that overlap each other and result in checksum lookup failures later. Those failures can make file data read requests assume a checksum value of 0, but they will not return an error (-EIO for example) to userspace exactly because the expected checksum value 0 is a special value that makes the read bio endio callback return success and set all the bytes of the corresponding page with the value 0x01 (at fs/btrfs/inode.c:__readpage_endio_check()). From a userspace perspective this is equivalent to file corruption because we are not returning what was written to the file. Details about how this can happen, and why, are included inline in the following reproducer test case for fstests and the comment added to tree-log.c. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _require_cloner _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with a single 100K extent starting at file # offset 800K. We fsync the file here to make the fsync log tree gets # a single csum item that covers the whole 100K extent, which causes # the second fsync, done after the cloning operation below, to not # leave in the log tree two csum items covering two sub-ranges # ([0, 20K[ and [20K, 100K[)) of our extent. $XFS_IO_PROG -f -c "pwrite -S 0xaa 800K 100K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now clone part of our extent into file offset 400K. This adds a file # extent item to our inode's metadata that points to the 100K extent # we created before, using a data offset of 20K and a data length of # 20K, so that it refers to the sub-range [20K, 40K[ of our original # extent. $CLONER_PROG -s $((800 * 1024 + 20 * 1024)) -d $((400 * 1024)) \ -l $((20 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo # Now fsync our file to make sure the extent cloning is durably # persisted. This fsync will not add a second csum item to the log # tree containing the checksums for the blocks in the sub-range # [20K, 40K[ of our extent, because there was already a csum item in # the log tree covering the whole extent, added by the first fsync # we did before. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo echo "File digest before power failure:" md5sum $SCRATCH_MNT/foo | _filter_scratch # Silently drop all writes and ummount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. # The fsync log replay first processes the file extent item # corresponding to the file offset 400K (the one which refers to the # [20K, 40K[ sub-range of our 100K extent) and then processes the file # extent item for file offset 800K. It used to happen that when # processing the later, it erroneously left in the csum tree 2 csum # items that overlapped each other, 1 for the sub-range [20K, 40K[ and # 1 for the whole range of our extent. This introduced a problem where # subsequent lookups for the checksums of blocks within the range # [40K, 100K[ of our extent would not find anything because lookups in # the csum tree ended up looking only at the smaller csum item, the # one covering the subrange [20K, 40K[. This made read requests assume # an expected checksum with a value of 0 for those blocks, which caused # checksum verification failure when the read operations finished. # However those checksum failure did not result in read requests # returning an error to user space (like -EIO for e.g.) because the # expected checksum value had the special value 0, and in that case # btrfs set all bytes of the corresponding pages with the value 0x01 # and produce the following warning in dmesg/syslog: # # "BTRFS warning (device dm-0): csum failed ino 257 off 917504 csum\ # 1322675045 expected csum 0" # _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File digest after log replay:" # Must match the same digest he had after cloning the extent and # before the power failure happened. md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-19 10:09:40 +00:00
/*
* Now delete all existing cums in the csum root that
* cover our range. We do this because we can have an
* extent that is completely referenced by one file
* extent item and partially referenced by another
* file extent item (like after using the clone or
* extent_same ioctls). In this case if we end up doing
* the replay of the one that partially references the
* extent first, and we do not do the csum deletion
* below, we can get 2 csum items in the csum tree that
* overlap each other. For example, imagine our log has
* the two following file extent items:
*
* key (257 EXTENT_DATA 409600)
* extent data disk byte 12845056 nr 102400
* extent data offset 20480 nr 20480 ram 102400
*
* key (257 EXTENT_DATA 819200)
* extent data disk byte 12845056 nr 102400
* extent data offset 0 nr 102400 ram 102400
*
* Where the second one fully references the 100K extent
* that starts at disk byte 12845056, and the log tree
* has a single csum item that covers the entire range
* of the extent:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
*
* After the first file extent item is replayed, the
* csum tree gets the following csum item:
*
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which covers the 20K sub-range starting at offset 20K
* of our extent. Now when we replay the second file
* extent item, if we do not delete existing csum items
* that cover any of its blocks, we end up getting two
* csum items in our csum tree that overlap each other:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which is a problem, because after this anyone trying
* to lookup up for the checksum of any block of our
* extent starting at an offset of 40K or higher, will
* end up looking at the second csum item only, which
* does not contain the checksum for any block starting
* at offset 40K or higher of our extent.
*/
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums;
sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
Btrfs: fix file read corruption after extent cloning and fsync If we partially clone one extent of a file into a lower offset of the file, fsync the file, power fail and then mount the fs to trigger log replay, we can get multiple checksum items in the csum tree that overlap each other and result in checksum lookup failures later. Those failures can make file data read requests assume a checksum value of 0, but they will not return an error (-EIO for example) to userspace exactly because the expected checksum value 0 is a special value that makes the read bio endio callback return success and set all the bytes of the corresponding page with the value 0x01 (at fs/btrfs/inode.c:__readpage_endio_check()). From a userspace perspective this is equivalent to file corruption because we are not returning what was written to the file. Details about how this can happen, and why, are included inline in the following reproducer test case for fstests and the comment added to tree-log.c. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _require_cloner _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with a single 100K extent starting at file # offset 800K. We fsync the file here to make the fsync log tree gets # a single csum item that covers the whole 100K extent, which causes # the second fsync, done after the cloning operation below, to not # leave in the log tree two csum items covering two sub-ranges # ([0, 20K[ and [20K, 100K[)) of our extent. $XFS_IO_PROG -f -c "pwrite -S 0xaa 800K 100K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now clone part of our extent into file offset 400K. This adds a file # extent item to our inode's metadata that points to the 100K extent # we created before, using a data offset of 20K and a data length of # 20K, so that it refers to the sub-range [20K, 40K[ of our original # extent. $CLONER_PROG -s $((800 * 1024 + 20 * 1024)) -d $((400 * 1024)) \ -l $((20 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo # Now fsync our file to make sure the extent cloning is durably # persisted. This fsync will not add a second csum item to the log # tree containing the checksums for the blocks in the sub-range # [20K, 40K[ of our extent, because there was already a csum item in # the log tree covering the whole extent, added by the first fsync # we did before. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo echo "File digest before power failure:" md5sum $SCRATCH_MNT/foo | _filter_scratch # Silently drop all writes and ummount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. # The fsync log replay first processes the file extent item # corresponding to the file offset 400K (the one which refers to the # [20K, 40K[ sub-range of our 100K extent) and then processes the file # extent item for file offset 800K. It used to happen that when # processing the later, it erroneously left in the csum tree 2 csum # items that overlapped each other, 1 for the sub-range [20K, 40K[ and # 1 for the whole range of our extent. This introduced a problem where # subsequent lookups for the checksums of blocks within the range # [40K, 100K[ of our extent would not find anything because lookups in # the csum tree ended up looking only at the smaller csum item, the # one covering the subrange [20K, 40K[. This made read requests assume # an expected checksum with a value of 0 for those blocks, which caused # checksum verification failure when the read operations finished. # However those checksum failure did not result in read requests # returning an error to user space (like -EIO for e.g.) because the # expected checksum value had the special value 0, and in that case # btrfs set all bytes of the corresponding pages with the value 0x01 # and produce the following warning in dmesg/syslog: # # "BTRFS warning (device dm-0): csum failed ino 257 off 917504 csum\ # 1322675045 expected csum 0" # _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File digest after log replay:" # Must match the same digest he had after cloning the extent and # before the power failure happened. md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-19 10:09:40 +00:00
if (!ret)
ret = btrfs_del_csums(trans, fs_info,
sums->bytenr,
sums->len);
if (!ret)
ret = btrfs_csum_file_blocks(trans,
fs_info->csum_root, sums);
list_del(&sums->list);
kfree(sums);
}
if (ret)
goto out;
} else {
btrfs_release_path(path);
}
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
/* inline extents are easy, we just overwrite them */
ret = overwrite_item(trans, root, path, eb, slot, key);
if (ret)
goto out;
}
inode_add_bytes(inode, nbytes);
update_inode:
ret = btrfs_update_inode(trans, root, inode);
out:
if (inode)
iput(inode);
return ret;
}
/*
* when cleaning up conflicts between the directory names in the
* subvolume, directory names in the log and directory names in the
* inode back references, we may have to unlink inodes from directories.
*
* This is a helper function to do the unlink of a specific directory
* item
*/
static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_inode *dir,
struct btrfs_dir_item *di)
{
struct inode *inode;
char *name;
int name_len;
struct extent_buffer *leaf;
struct btrfs_key location;
int ret;
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
name_len = btrfs_dir_name_len(leaf, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name)
return -ENOMEM;
read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
btrfs_release_path(path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
ret = -EIO;
goto out;
}
ret = link_to_fixup_dir(trans, root, path, location.objectid);
if (ret)
goto out;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
ret = btrfs_unlink_inode(trans, root, dir, BTRFS_I(inode), name,
name_len);
if (ret)
goto out;
else
ret = btrfs_run_delayed_items(trans);
out:
kfree(name);
iput(inode);
return ret;
}
/*
* helper function to see if a given name and sequence number found
* in an inode back reference are already in a directory and correctly
* point to this inode
*/
static noinline int inode_in_dir(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, u64 objectid, u64 index,
const char *name, int name_len)
{
struct btrfs_dir_item *di;
struct btrfs_key location;
int match = 0;
di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
index, name, name_len, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else
goto out;
btrfs_release_path(path);
di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else
goto out;
match = 1;
out:
btrfs_release_path(path);
return match;
}
/*
* helper function to check a log tree for a named back reference in
* an inode. This is used to decide if a back reference that is
* found in the subvolume conflicts with what we find in the log.
*
* inode backreferences may have multiple refs in a single item,
* during replay we process one reference at a time, and we don't
* want to delete valid links to a file from the subvolume if that
* link is also in the log.
*/
static noinline int backref_in_log(struct btrfs_root *log,
struct btrfs_key *key,
u64 ref_objectid,
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
const char *name, int namelen)
{
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
unsigned long ptr;
unsigned long ptr_end;
unsigned long name_ptr;
int found_name_len;
int item_size;
int ret;
int match = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
if (ret != 0)
goto out;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
if (btrfs_find_name_in_ext_backref(path->nodes[0],
path->slots[0],
ref_objectid,
name, namelen))
match = 1;
goto out;
}
item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
ref = (struct btrfs_inode_ref *)ptr;
found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
if (found_name_len == namelen) {
name_ptr = (unsigned long)(ref + 1);
ret = memcmp_extent_buffer(path->nodes[0], name,
name_ptr, namelen);
if (ret == 0) {
match = 1;
goto out;
}
}
ptr = (unsigned long)(ref + 1) + found_name_len;
}
out:
btrfs_free_path(path);
return match;
}
static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_root *log_root,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
u64 inode_objectid, u64 parent_objectid,
u64 ref_index, char *name, int namelen,
int *search_done)
{
int ret;
char *victim_name;
int victim_name_len;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key search_key;
struct btrfs_inode_extref *extref;
again:
/* Search old style refs */
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = parent_objectid;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret == 0) {
struct btrfs_inode_ref *victim_ref;
unsigned long ptr;
unsigned long ptr_end;
leaf = path->nodes[0];
/* are we trying to overwrite a back ref for the root directory
* if so, just jump out, we're done
*/
if (search_key.objectid == search_key.offset)
return 1;
/* check all the names in this back reference to see
* if they are in the log. if so, we allow them to stay
* otherwise they must be unlinked as a conflict
*/
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
while (ptr < ptr_end) {
victim_ref = (struct btrfs_inode_ref *)ptr;
victim_name_len = btrfs_inode_ref_name_len(leaf,
victim_ref);
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name,
(unsigned long)(victim_ref + 1),
victim_name_len);
if (!backref_in_log(log_root, &search_key,
parent_objectid,
victim_name,
victim_name_len)) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
ret = btrfs_unlink_inode(trans, root, dir, inode,
victim_name, victim_name_len);
kfree(victim_name);
if (ret)
return ret;
ret = btrfs_run_delayed_items(trans);
if (ret)
return ret;
*search_done = 1;
goto again;
}
kfree(victim_name);
ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
}
/*
* NOTE: we have searched root tree and checked the
* corresponding ref, it does not need to check again.
*/
*search_done = 1;
}
btrfs_release_path(path);
/* Same search but for extended refs */
extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
inode_objectid, parent_objectid, 0,
0);
if (!IS_ERR_OR_NULL(extref)) {
u32 item_size;
u32 cur_offset = 0;
unsigned long base;
struct inode *victim_parent;
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
base = btrfs_item_ptr_offset(leaf, path->slots[0]);
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *)(base + cur_offset);
victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
goto next;
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
victim_name_len);
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(parent_objectid,
victim_name,
victim_name_len);
ret = 0;
if (!backref_in_log(log_root, &search_key,
parent_objectid, victim_name,
victim_name_len)) {
ret = -ENOENT;
victim_parent = read_one_inode(root,
parent_objectid);
if (victim_parent) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = btrfs_unlink_inode(trans, root,
BTRFS_I(victim_parent),
inode,
victim_name,
victim_name_len);
if (!ret)
ret = btrfs_run_delayed_items(
trans);
}
iput(victim_parent);
kfree(victim_name);
if (ret)
return ret;
*search_done = 1;
goto again;
}
kfree(victim_name);
next:
cur_offset += victim_name_len + sizeof(*extref);
}
*search_done = 1;
}
btrfs_release_path(path);
/* look for a conflicting sequence number */
di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
ref_index, name, namelen, 0);
if (di && !IS_ERR(di)) {
ret = drop_one_dir_item(trans, root, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
/* look for a conflicting name */
di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
name, namelen, 0);
if (di && !IS_ERR(di)) {
ret = drop_one_dir_item(trans, root, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
return 0;
}
static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
u32 *namelen, char **name, u64 *index,
u64 *parent_objectid)
{
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ref_ptr;
*namelen = btrfs_inode_extref_name_len(eb, extref);
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)&extref->name,
*namelen);
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
if (index)
*index = btrfs_inode_extref_index(eb, extref);
if (parent_objectid)
*parent_objectid = btrfs_inode_extref_parent(eb, extref);
return 0;
}
static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
u32 *namelen, char **name, u64 *index)
{
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ref_ptr;
*namelen = btrfs_inode_ref_name_len(eb, ref);
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
if (index)
*index = btrfs_inode_ref_index(eb, ref);
return 0;
}
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
/*
* Take an inode reference item from the log tree and iterate all names from the
* inode reference item in the subvolume tree with the same key (if it exists).
* For any name that is not in the inode reference item from the log tree, do a
* proper unlink of that name (that is, remove its entry from the inode
* reference item and both dir index keys).
*/
static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_inode *inode,
struct extent_buffer *log_eb,
int log_slot,
struct btrfs_key *key)
{
int ret;
unsigned long ref_ptr;
unsigned long ref_end;
struct extent_buffer *eb;
again:
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret > 0) {
ret = 0;
goto out;
}
if (ret < 0)
goto out;
eb = path->nodes[0];
ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]);
while (ref_ptr < ref_end) {
char *name = NULL;
int namelen;
u64 parent_id;
if (key->type == BTRFS_INODE_EXTREF_KEY) {
ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
NULL, &parent_id);
} else {
parent_id = key->offset;
ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
NULL);
}
if (ret)
goto out;
if (key->type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
parent_id, name,
namelen);
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
else
ret = !!btrfs_find_name_in_backref(log_eb, log_slot,
name, namelen);
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
if (!ret) {
struct inode *dir;
btrfs_release_path(path);
dir = read_one_inode(root, parent_id);
if (!dir) {
ret = -ENOENT;
kfree(name);
goto out;
}
ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
inode, name, namelen);
kfree(name);
iput(dir);
if (ret)
goto out;
goto again;
}
kfree(name);
ref_ptr += namelen;
if (key->type == BTRFS_INODE_EXTREF_KEY)
ref_ptr += sizeof(struct btrfs_inode_extref);
else
ref_ptr += sizeof(struct btrfs_inode_ref);
}
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
Btrfs: fix mount failure after fsync due to hard link recreation If we end up with logging an inode reference item which has the same name but different index from the one we have persisted, we end up failing when replaying the log with an errno value of -EEXIST. The error comes from btrfs_add_link(), which is called from add_inode_ref(), when we are replaying an inode reference item. Example scenario where this happens: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ touch /mnt/foo $ ln /mnt/foo /mnt/bar $ sync # Rename the first hard link (foo) to a new name and rename the second # hard link (bar) to the old name of the first hard link (foo). $ mv /mnt/foo /mnt/qwerty $ mv /mnt/bar /mnt/foo # Create a new file, in the same parent directory, with the old name of # the second hard link (bar) and fsync this new file. # We do this instead of calling fsync on foo/qwerty because if we did # that the fsync resulted in a full transaction commit, not triggering # the problem. $ touch /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power fail> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking if a conflicting inode reference exists (same name, same parent but different index), removing it (and the associated dir index entries from the parent inode) if it exists, before attempting to add the new reference. A test case for fstests follows soon. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-20 09:59:06 +00:00
static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir,
const u8 ref_type, const char *name,
const int namelen)
{
struct btrfs_key key;
struct btrfs_path *path;
const u64 parent_id = btrfs_ino(BTRFS_I(dir));
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = btrfs_ino(BTRFS_I(inode));
key.type = ref_type;
if (key.type == BTRFS_INODE_REF_KEY)
key.offset = parent_id;
else
key.offset = btrfs_extref_hash(parent_id, name, namelen);
ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
goto out;
}
if (key.type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
path->slots[0], parent_id, name, namelen);
Btrfs: fix mount failure after fsync due to hard link recreation If we end up with logging an inode reference item which has the same name but different index from the one we have persisted, we end up failing when replaying the log with an errno value of -EEXIST. The error comes from btrfs_add_link(), which is called from add_inode_ref(), when we are replaying an inode reference item. Example scenario where this happens: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ touch /mnt/foo $ ln /mnt/foo /mnt/bar $ sync # Rename the first hard link (foo) to a new name and rename the second # hard link (bar) to the old name of the first hard link (foo). $ mv /mnt/foo /mnt/qwerty $ mv /mnt/bar /mnt/foo # Create a new file, in the same parent directory, with the old name of # the second hard link (bar) and fsync this new file. # We do this instead of calling fsync on foo/qwerty because if we did # that the fsync resulted in a full transaction commit, not triggering # the problem. $ touch /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power fail> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking if a conflicting inode reference exists (same name, same parent but different index), removing it (and the associated dir index entries from the parent inode) if it exists, before attempting to add the new reference. A test case for fstests follows soon. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-20 09:59:06 +00:00
else
ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
name, namelen);
Btrfs: fix mount failure after fsync due to hard link recreation If we end up with logging an inode reference item which has the same name but different index from the one we have persisted, we end up failing when replaying the log with an errno value of -EEXIST. The error comes from btrfs_add_link(), which is called from add_inode_ref(), when we are replaying an inode reference item. Example scenario where this happens: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ touch /mnt/foo $ ln /mnt/foo /mnt/bar $ sync # Rename the first hard link (foo) to a new name and rename the second # hard link (bar) to the old name of the first hard link (foo). $ mv /mnt/foo /mnt/qwerty $ mv /mnt/bar /mnt/foo # Create a new file, in the same parent directory, with the old name of # the second hard link (bar) and fsync this new file. # We do this instead of calling fsync on foo/qwerty because if we did # that the fsync resulted in a full transaction commit, not triggering # the problem. $ touch /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power fail> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking if a conflicting inode reference exists (same name, same parent but different index), removing it (and the associated dir index entries from the parent inode) if it exists, before attempting to add the new reference. A test case for fstests follows soon. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-20 09:59:06 +00:00
out:
btrfs_free_path(path);
return ret;
}
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
static int add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct inode *dir, struct inode *inode, const char *name,
int namelen, u64 ref_index)
{
struct btrfs_dir_item *dir_item;
struct btrfs_key key;
struct btrfs_path *path;
struct inode *other_inode = NULL;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dir_item = btrfs_lookup_dir_item(NULL, root, path,
btrfs_ino(BTRFS_I(dir)),
name, namelen, 0);
if (!dir_item) {
btrfs_release_path(path);
goto add_link;
} else if (IS_ERR(dir_item)) {
ret = PTR_ERR(dir_item);
goto out;
}
/*
* Our inode's dentry collides with the dentry of another inode which is
* in the log but not yet processed since it has a higher inode number.
* So delete that other dentry.
*/
btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &key);
btrfs_release_path(path);
other_inode = read_one_inode(root, key.objectid);
if (!other_inode) {
ret = -ENOENT;
goto out;
}
ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(other_inode),
name, namelen);
if (ret)
goto out;
/*
* If we dropped the link count to 0, bump it so that later the iput()
* on the inode will not free it. We will fixup the link count later.
*/
if (other_inode->i_nlink == 0)
inc_nlink(other_inode);
ret = btrfs_run_delayed_items(trans);
if (ret)
goto out;
add_link:
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
name, namelen, 0, ref_index);
out:
iput(other_inode);
btrfs_free_path(path);
return ret;
}
/*
* replay one inode back reference item found in the log tree.
* eb, slot and key refer to the buffer and key found in the log tree.
* root is the destination we are replaying into, and path is for temp
* use by this function. (it should be released on return).
*/
static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct inode *dir = NULL;
struct inode *inode = NULL;
unsigned long ref_ptr;
unsigned long ref_end;
char *name = NULL;
int namelen;
int ret;
int search_done = 0;
int log_ref_ver = 0;
u64 parent_objectid;
u64 inode_objectid;
u64 ref_index = 0;
int ref_struct_size;
ref_ptr = btrfs_item_ptr_offset(eb, slot);
ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *r;
ref_struct_size = sizeof(struct btrfs_inode_extref);
log_ref_ver = 1;
r = (struct btrfs_inode_extref *)ref_ptr;
parent_objectid = btrfs_inode_extref_parent(eb, r);
} else {
ref_struct_size = sizeof(struct btrfs_inode_ref);
parent_objectid = key->offset;
}
inode_objectid = key->objectid;
/*
* it is possible that we didn't log all the parent directories
* for a given inode. If we don't find the dir, just don't
* copy the back ref in. The link count fixup code will take
* care of the rest
*/
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
inode = read_one_inode(root, inode_objectid);
if (!inode) {
ret = -EIO;
goto out;
}
while (ref_ptr < ref_end) {
if (log_ref_ver) {
ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
&ref_index, &parent_objectid);
/*
* parent object can change from one array
* item to another.
*/
if (!dir)
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
} else {
ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
&ref_index);
}
if (ret)
goto out;
/* if we already have a perfect match, we're done */
if (!inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
btrfs_ino(BTRFS_I(inode)), ref_index,
name, namelen)) {
/*
* look for a conflicting back reference in the
* metadata. if we find one we have to unlink that name
* of the file before we add our new link. Later on, we
* overwrite any existing back reference, and we don't
* want to create dangling pointers in the directory.
*/
if (!search_done) {
ret = __add_inode_ref(trans, root, path, log,
BTRFS_I(dir),
BTRFS_I(inode),
inode_objectid,
parent_objectid,
ref_index, name, namelen,
&search_done);
if (ret) {
if (ret == 1)
ret = 0;
goto out;
}
}
Btrfs: fix mount failure after fsync due to hard link recreation If we end up with logging an inode reference item which has the same name but different index from the one we have persisted, we end up failing when replaying the log with an errno value of -EEXIST. The error comes from btrfs_add_link(), which is called from add_inode_ref(), when we are replaying an inode reference item. Example scenario where this happens: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ touch /mnt/foo $ ln /mnt/foo /mnt/bar $ sync # Rename the first hard link (foo) to a new name and rename the second # hard link (bar) to the old name of the first hard link (foo). $ mv /mnt/foo /mnt/qwerty $ mv /mnt/bar /mnt/foo # Create a new file, in the same parent directory, with the old name of # the second hard link (bar) and fsync this new file. # We do this instead of calling fsync on foo/qwerty because if we did # that the fsync resulted in a full transaction commit, not triggering # the problem. $ touch /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power fail> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking if a conflicting inode reference exists (same name, same parent but different index), removing it (and the associated dir index entries from the parent inode) if it exists, before attempting to add the new reference. A test case for fstests follows soon. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-07-20 09:59:06 +00:00
/*
* If a reference item already exists for this inode
* with the same parent and name, but different index,
* drop it and the corresponding directory index entries
* from the parent before adding the new reference item
* and dir index entries, otherwise we would fail with
* -EEXIST returned from btrfs_add_link() below.
*/
ret = btrfs_inode_ref_exists(inode, dir, key->type,
name, namelen);
if (ret > 0) {
ret = btrfs_unlink_inode(trans, root,
BTRFS_I(dir),
BTRFS_I(inode),
name, namelen);
/*
* If we dropped the link count to 0, bump it so
* that later the iput() on the inode will not
* free it. We will fixup the link count later.
*/
if (!ret && inode->i_nlink == 0)
inc_nlink(inode);
}
if (ret < 0)
goto out;
/* insert our name */
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
ret = add_link(trans, root, dir, inode, name, namelen,
ref_index);
if (ret)
goto out;
btrfs_update_inode(trans, root, inode);
}
ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
kfree(name);
name = NULL;
if (log_ref_ver) {
iput(dir);
dir = NULL;
}
}
Btrfs: fix log replay failure after unlink and link combination If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:56:10 +00:00
/*
* Before we overwrite the inode reference item in the subvolume tree
* with the item from the log tree, we must unlink all names from the
* parent directory that are in the subvolume's tree inode reference
* item, otherwise we end up with an inconsistent subvolume tree where
* dir index entries exist for a name but there is no inode reference
* item with the same name.
*/
ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
key);
if (ret)
goto out;
/* finally write the back reference in the inode */
ret = overwrite_item(trans, root, path, eb, slot, key);
out:
btrfs_release_path(path);
kfree(name);
iput(dir);
iput(inode);
return ret;
}
static int insert_orphan_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 ino)
{
int ret;
ret = btrfs_insert_orphan_item(trans, root, ino);
if (ret == -EEXIST)
ret = 0;
return ret;
}
static int count_inode_extrefs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret = 0;
int name_len;
unsigned int nlink = 0;
u32 item_size;
u32 cur_offset = 0;
u64 inode_objectid = btrfs_ino(inode);
u64 offset = 0;
unsigned long ptr;
struct btrfs_inode_extref *extref;
struct extent_buffer *leaf;
while (1) {
ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
&extref, &offset);
if (ret)
break;
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
Btrfs: fix fsync when extend references are added to an inode If we added an extended reference to an inode and fsync'ed it, the log replay code would make our inode have an incorrect link count, which was lower then the expected/correct count. This resulted in stale directory index entries after deleting some of the hard links, and any access to the dangling directory entries resulted in -ESTALE errors because the entries pointed to inode items that don't exist anymore. This is easy to reproduce with the test case I made for xfstests, and the bulk of that test is: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Add one more link to the inode that ends up being a btrfs extref and fsync # the inode. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now after the fsync log replay btrfs left our inode with a wrong link count N, # which was smaller than the correct link count M (N < M). # So after removing N hard links, the remaining M - N directory entries were # still visible to user space but it was impossible to do anything with them # because they pointed to an inode that didn't exist anymore. This resulted in # stale file handle errors (-ESTALE) when accessing those dentries for example. # # So remove all hard links except the first one and then attempt to read the # file, to verify we don't get an -ESTALE error when accessing the inodel # # The btrfs fsck tool also detected the incorrect inode link count and it # reported an error message like the following: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref # # The fstests framework automatically calls fsck after a test is run, so we # don't need to call fsck explicitly here. rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo status=0 exit So make sure an fsync always flushes the delayed inode item, so that the fsync log contains it (needed in order to trigger the link count fixup code) and fix the extref counting function, which always return -ENOENT to its caller (and made it assume there were always 0 extrefs). This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-13 16:40:04 +00:00
cur_offset = 0;
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
name_len = btrfs_inode_extref_name_len(leaf, extref);
nlink++;
cur_offset += name_len + sizeof(*extref);
}
offset++;
btrfs_release_path(path);
}
btrfs_release_path(path);
Btrfs: fix fsync when extend references are added to an inode If we added an extended reference to an inode and fsync'ed it, the log replay code would make our inode have an incorrect link count, which was lower then the expected/correct count. This resulted in stale directory index entries after deleting some of the hard links, and any access to the dangling directory entries resulted in -ESTALE errors because the entries pointed to inode items that don't exist anymore. This is easy to reproduce with the test case I made for xfstests, and the bulk of that test is: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Add one more link to the inode that ends up being a btrfs extref and fsync # the inode. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now after the fsync log replay btrfs left our inode with a wrong link count N, # which was smaller than the correct link count M (N < M). # So after removing N hard links, the remaining M - N directory entries were # still visible to user space but it was impossible to do anything with them # because they pointed to an inode that didn't exist anymore. This resulted in # stale file handle errors (-ESTALE) when accessing those dentries for example. # # So remove all hard links except the first one and then attempt to read the # file, to verify we don't get an -ESTALE error when accessing the inodel # # The btrfs fsck tool also detected the incorrect inode link count and it # reported an error message like the following: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref # # The fstests framework automatically calls fsck after a test is run, so we # don't need to call fsck explicitly here. rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo status=0 exit So make sure an fsync always flushes the delayed inode item, so that the fsync log contains it (needed in order to trigger the link count fixup code) and fix the extref counting function, which always return -ENOENT to its caller (and made it assume there were always 0 extrefs). This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-13 16:40:04 +00:00
if (ret < 0 && ret != -ENOENT)
return ret;
return nlink;
}
static int count_inode_refs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
unsigned int nlink = 0;
unsigned long ptr;
unsigned long ptr_end;
int name_len;
u64 ino = btrfs_ino(inode);
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
process_slot:
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid != ino ||
key.type != BTRFS_INODE_REF_KEY)
break;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
path->slots[0]);
while (ptr < ptr_end) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
name_len = btrfs_inode_ref_name_len(path->nodes[0],
ref);
ptr = (unsigned long)(ref + 1) + name_len;
nlink++;
}
if (key.offset == 0)
break;
if (path->slots[0] > 0) {
path->slots[0]--;
goto process_slot;
}
key.offset--;
btrfs_release_path(path);
}
btrfs_release_path(path);
return nlink;
}
/*
* There are a few corners where the link count of the file can't
* be properly maintained during replay. So, instead of adding
* lots of complexity to the log code, we just scan the backrefs
* for any file that has been through replay.
*
* The scan will update the link count on the inode to reflect the
* number of back refs found. If it goes down to zero, the iput
* will free the inode.
*/
static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_path *path;
int ret;
u64 nlink = 0;
u64 ino = btrfs_ino(BTRFS_I(inode));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = count_inode_refs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink = ret;
ret = count_inode_extrefs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink += ret;
ret = 0;
if (nlink != inode->i_nlink) {
set_nlink(inode, nlink);
btrfs_update_inode(trans, root, inode);
}
BTRFS_I(inode)->index_cnt = (u64)-1;
if (inode->i_nlink == 0) {
if (S_ISDIR(inode->i_mode)) {
ret = replay_dir_deletes(trans, root, NULL, path,
ino, 1);
if (ret)
goto out;
}
ret = insert_orphan_item(trans, root, ino);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
}
out:
btrfs_free_path(path);
return ret;
}
static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
struct inode *inode;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
break;
if (ret == 1) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
ret = btrfs_del_item(trans, root, path);
if (ret)
goto out;
btrfs_release_path(path);
inode = read_one_inode(root, key.offset);
if (!inode)
return -EIO;
ret = fixup_inode_link_count(trans, root, inode);
iput(inode);
if (ret)
goto out;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* fixup on a directory may create new entries,
* make sure we always look for the highset possible
* offset
*/
key.offset = (u64)-1;
}
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* record a given inode in the fixup dir so we can check its link
* count when replay is done. The link count is incremented here
* so the inode won't go away until we check it
*/
static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid)
{
struct btrfs_key key;
int ret = 0;
struct inode *inode;
inode = read_one_inode(root, objectid);
if (!inode)
return -EIO;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = objectid;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(path);
if (ret == 0) {
if (!inode->i_nlink)
set_nlink(inode, 1);
else
inc_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
} else if (ret == -EEXIST) {
ret = 0;
} else {
BUG(); /* Logic Error */
}
iput(inode);
return ret;
}
/*
* when replaying the log for a directory, we only insert names
* for inodes that actually exist. This means an fsync on a directory
* does not implicitly fsync all the new files in it
*/
static noinline int insert_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 dirid, u64 index,
char *name, int name_len,
struct btrfs_key *location)
{
struct inode *inode;
struct inode *dir;
int ret;
inode = read_one_inode(root, location->objectid);
if (!inode)
return -ENOENT;
dir = read_one_inode(root, dirid);
if (!dir) {
iput(inode);
return -EIO;
}
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
name_len, 1, index);
/* FIXME, put inode into FIXUP list */
iput(inode);
iput(dir);
return ret;
}
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
/*
* Return true if an inode reference exists in the log for the given name,
* inode and parent inode.
*/
static bool name_in_log_ref(struct btrfs_root *log_root,
const char *name, const int name_len,
const u64 dirid, const u64 ino)
{
struct btrfs_key search_key;
search_key.objectid = ino;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = dirid;
if (backref_in_log(log_root, &search_key, dirid, name, name_len))
return true;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(dirid, name, name_len);
if (backref_in_log(log_root, &search_key, dirid, name, name_len))
return true;
return false;
}
/*
* take a single entry in a log directory item and replay it into
* the subvolume.
*
* if a conflicting item exists in the subdirectory already,
* the inode it points to is unlinked and put into the link count
* fix up tree.
*
* If a name from the log points to a file or directory that does
* not exist in the FS, it is skipped. fsyncs on directories
* do not force down inodes inside that directory, just changes to the
* names or unlinks in a directory.
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
*
* Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
* non-existing inode) and 1 if the name was replayed.
*/
static noinline int replay_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb,
struct btrfs_dir_item *di,
struct btrfs_key *key)
{
char *name;
int name_len;
struct btrfs_dir_item *dst_di;
struct btrfs_key found_key;
struct btrfs_key log_key;
struct inode *dir;
u8 log_type;
int exists;
int ret = 0;
bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
bool name_added = false;
dir = read_one_inode(root, key->objectid);
if (!dir)
return -EIO;
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
log_type = btrfs_dir_type(eb, di);
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
btrfs_dir_item_key_to_cpu(eb, di, &log_key);
exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
if (exists == 0)
exists = 1;
else
exists = 0;
btrfs_release_path(path);
if (key->type == BTRFS_DIR_ITEM_KEY) {
dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
name, name_len, 1);
} else if (key->type == BTRFS_DIR_INDEX_KEY) {
dst_di = btrfs_lookup_dir_index_item(trans, root, path,
key->objectid,
key->offset, name,
name_len, 1);
} else {
/* Corruption */
ret = -EINVAL;
goto out;
}
if (IS_ERR_OR_NULL(dst_di)) {
/* we need a sequence number to insert, so we only
* do inserts for the BTRFS_DIR_INDEX_KEY types
*/
if (key->type != BTRFS_DIR_INDEX_KEY)
goto out;
goto insert;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
/* the existing item matches the logged item */
if (found_key.objectid == log_key.objectid &&
found_key.type == log_key.type &&
found_key.offset == log_key.offset &&
btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
update_size = false;
goto out;
}
/*
* don't drop the conflicting directory entry if the inode
* for the new entry doesn't exist
*/
if (!exists)
goto out;
ret = drop_one_dir_item(trans, root, path, BTRFS_I(dir), dst_di);
if (ret)
goto out;
if (key->type == BTRFS_DIR_INDEX_KEY)
goto insert;
out:
btrfs_release_path(path);
if (!ret && update_size) {
btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2);
ret = btrfs_update_inode(trans, root, dir);
}
kfree(name);
iput(dir);
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
if (!ret && name_added)
ret = 1;
return ret;
insert:
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
if (name_in_log_ref(root->log_root, name, name_len,
key->objectid, log_key.objectid)) {
/* The dentry will be added later. */
ret = 0;
update_size = false;
goto out;
}
btrfs_release_path(path);
ret = insert_one_name(trans, root, key->objectid, key->offset,
name, name_len, &log_key);
Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs If we have an inode with a large number of hard links, some of which may be extrefs, turn a regular ref into an extref, fsync the inode and then replay the fsync log (after a crash/reboot), we can endup with an fsync log that makes the replay code always fail with -EOVERFLOW when processing the inode's references. This is easy to reproduce with the test case I made for xfstests. Its steps are the following: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Now remove one link, add a new one with a new name, add another new one with # the same name as the one we just removed and fsync the inode. rm -f $SCRATCH_MNT/foo_link_0001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001 rm -f $SCRATCH_MNT/foo_link_0002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002 ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Check that the number of hard links is correct, we are able to remove all # the hard links and read the file's data. This is just to verify we don't # get stale file handle errors (due to dangling directory index entries that # point to inodes that no longer exist). echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)" [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing" for ((i = 1; i <= 3003; i++)); do name=foo_link_`printf "%04d" $i` if [ $i -eq 2 ]; then [ -f $SCRATCH_MNT/$name ] && echo "Link $name found" else [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing" fi done rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo rm -f $SCRATCH_MNT/foo status=0 exit The fix is simply to correct the overflow condition when overwriting a reference item because it was wrong, trying to increase the item in the fs/subvol tree by an impossible amount. Also ensure that we don't insert one normal ref and one ext ref for the same dentry - this happened because processing a dir index entry from the parent in the log happened when the normal ref item was full, which made the logic insert an extref and later when the normal ref had enough room, it would be inserted again when processing the ref item from the child inode in the log. This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. This test only passes if the previous patch titled "Btrfs: fix fsync when extend references are added to an inode" is applied too. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-14 01:52:25 +00:00
if (ret && ret != -ENOENT && ret != -EEXIST)
goto out;
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
if (!ret)
name_added = true;
update_size = false;
ret = 0;
goto out;
}
/*
* find all the names in a directory item and reconcile them into
* the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
* one name in a directory item, but the same code gets used for
* both directory index types
*/
static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
int ret = 0;
u32 item_size = btrfs_item_size_nr(eb, slot);
struct btrfs_dir_item *di;
int name_len;
unsigned long ptr;
unsigned long ptr_end;
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
struct btrfs_path *fixup_path = NULL;
ptr = btrfs_item_ptr_offset(eb, slot);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
di = (struct btrfs_dir_item *)ptr;
name_len = btrfs_dir_name_len(eb, di);
ret = replay_one_name(trans, root, path, eb, di, key);
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
if (ret < 0)
break;
ptr = (unsigned long)(di + 1);
ptr += name_len;
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
/*
* If this entry refers to a non-directory (directories can not
* have a link count > 1) and it was added in the transaction
* that was not committed, make sure we fixup the link count of
* the inode it the entry points to. Otherwise something like
* the following would result in a directory pointing to an
* inode with a wrong link that does not account for this dir
* entry:
*
* mkdir testdir
* touch testdir/foo
* touch testdir/bar
* sync
*
* ln testdir/bar testdir/bar_link
* ln testdir/foo testdir/foo_link
* xfs_io -c "fsync" testdir/bar
*
* <power failure>
*
* mount fs, log replay happens
*
* File foo would remain with a link count of 1 when it has two
* entries pointing to it in the directory testdir. This would
* make it impossible to ever delete the parent directory has
* it would result in stale dentries that can never be deleted.
*/
if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
struct btrfs_key di_key;
if (!fixup_path) {
fixup_path = btrfs_alloc_path();
if (!fixup_path) {
ret = -ENOMEM;
break;
}
}
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
ret = link_to_fixup_dir(trans, root, fixup_path,
di_key.objectid);
if (ret)
break;
}
ret = 0;
}
Btrfs: fix stale directory entries after fsync log replay We have another case where after an fsync log replay we get an inode with a wrong link count (smaller than it should be) and a number of directory entries greater than its link count. This happens when we add a new link hard link to our inode A and then we fsync some other inode B that has the side effect of logging the parent directory inode too. In this case at log replay time we add the new hard link to our inode (the item with key BTRFS_INODE_REF_KEY) when processing the parent directory but we never adjust the link count of our inode A. As a result we get stale dir entries for our inode A that can never be deleted and therefore it makes it impossible to remove the parent directory (as its i_size can never decrease back to 0). A simple reproducer for fstests that triggers this issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and files. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/testdir/foo touch $SCRATCH_MNT/testdir/bar # Make sure everything done so far is durably persisted. sync # Create one hard link for file foo and another one for file bar. After # that fsync only the file bar. ln $SCRATCH_MNT/testdir/bar $SCRATCH_MNT/testdir/bar_link ln $SCRATCH_MNT/testdir/foo $SCRATCH_MNT/testdir/foo_link $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir/bar # Silently drop all writes on scratch device to simulate power failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount the fs to trigger log/journal replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now verify both our files have a link count of 2. echo "Link count for file foo: $(stat --format=%h $SCRATCH_MNT/testdir/foo)" echo "Link count for file bar: $(stat --format=%h $SCRATCH_MNT/testdir/bar)" # We should be able to remove all the links of our files in testdir, and # after that the parent directory should become empty and therefore # possible to remove it. rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey # The fstests framework will call fsck against our filesystem which will verify # that all metadata is in a consistent state. status=0 exit The test fails with: -Link count for file foo: 2 +Link count for file foo: 1 Link count for file bar: 2 +rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/testdir/foo_link': Stale file handle +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty (...) _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent And fsck's output: (...) checking fs roots root 5 inode 258 errors 2001, no inode item, link count wrong unresolved ref dir 257 index 5 namelen 8 name foo_link filetype 1 errors 4, no inode ref Checking filesystem on /dev/sdc (...) So fix this by marking inodes for link count fixup at log replay time whenever a directory entry is replayed if the entry was created in the transaction where the fsync was made and if it points to a non-directory inode. This isn't a new problem/regression, the issue exists for a long time, possibly since the log tree feature was added (2008). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-07-15 22:26:43 +00:00
btrfs_free_path(fixup_path);
return ret;
}
/*
* directory replay has two parts. There are the standard directory
* items in the log copied from the subvolume, and range items
* created in the log while the subvolume was logged.
*
* The range items tell us which parts of the key space the log
* is authoritative for. During replay, if a key in the subvolume
* directory is in a logged range item, but not actually in the log
* that means it was deleted from the directory before the fsync
* and should be removed.
*/
static noinline int find_dir_range(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, int key_type,
u64 *start_ret, u64 *end_ret)
{
struct btrfs_key key;
u64 found_end;
struct btrfs_dir_log_item *item;
int ret;
int nritems;
if (*start_ret == (u64)-1)
return 1;
key.objectid = dirid;
key.type = key_type;
key.offset = *start_ret;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
if (ret != 0)
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != key_type || key.objectid != dirid) {
ret = 1;
goto next;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
if (*start_ret >= key.offset && *start_ret <= found_end) {
ret = 0;
*start_ret = key.offset;
*end_ret = found_end;
goto out;
}
ret = 1;
next:
/* check the next slot in the tree to see if it is a valid item */
nritems = btrfs_header_nritems(path->nodes[0]);
Btrfs: fix tree search logic when replaying directory entry deletes If a log tree has a layout like the following: leaf N: ... item 240 key (282 DIR_LOG_ITEM 0) itemoff 8189 itemsize 8 dir log end 1275809046 leaf N + 1: item 0 key (282 DIR_LOG_ITEM 3936149215) itemoff 16275 itemsize 8 dir log end 18446744073709551615 ... When we pass the value 1275809046 + 1 as the parameter start_ret to the function tree-log.c:find_dir_range() (done by replay_dir_deletes()), we end up with path->slots[0] having the value 239 (points to the last item of leaf N, item 240). Because the dir log item in that position has an offset value smaller than *start_ret (1275809046 + 1) we need to move on to the next leaf, however the logic for that is wrong since it compares the current slot to the number of items in the leaf, which is smaller and therefore we don't lookup for the next leaf but instead we set the slot to point to an item that does not exist, at slot 240, and we later operate on that slot which has unexpected content or in the worst case can result in an invalid memory access (accessing beyond the last page of leaf N's extent buffer). So fix the logic that checks when we need to lookup at the next leaf by first incrementing the slot and only after to check if that slot is beyond the last item of the current leaf. Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Fixes: e02119d5a7b4 (Btrfs: Add a write ahead tree log to optimize synchronous operations) Cc: stable@vger.kernel.org # 2.6.29+ Signed-off-by: Filipe Manana <fdmanana@suse.com> [Modified changelog for clarity and correctness]
2016-10-07 09:30:47 +00:00
path->slots[0]++;
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != key_type || key.objectid != dirid) {
ret = 1;
goto out;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
*start_ret = key.offset;
*end_ret = found_end;
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* this looks for a given directory item in the log. If the directory
* item is not in the log, the item is removed and the inode it points
* to is unlinked
*/
static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_path *log_path,
struct inode *dir,
struct btrfs_key *dir_key)
{
int ret;
struct extent_buffer *eb;
int slot;
u32 item_size;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
int name_len;
unsigned long ptr;
unsigned long ptr_end;
char *name;
struct inode *inode;
struct btrfs_key location;
again:
eb = path->nodes[0];
slot = path->slots[0];
item_size = btrfs_item_size_nr(eb, slot);
ptr = btrfs_item_ptr_offset(eb, slot);
ptr_end = ptr + item_size;
while (ptr < ptr_end) {
di = (struct btrfs_dir_item *)ptr;
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
log_di = NULL;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
log_di = btrfs_lookup_dir_item(trans, log, log_path,
dir_key->objectid,
name, name_len, 0);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
} else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
log_di = btrfs_lookup_dir_index_item(trans, log,
log_path,
dir_key->objectid,
dir_key->offset,
name, name_len, 0);
}
if (!log_di || log_di == ERR_PTR(-ENOENT)) {
btrfs_dir_item_key_to_cpu(eb, di, &location);
btrfs_release_path(path);
btrfs_release_path(log_path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
kfree(name);
return -EIO;
}
ret = link_to_fixup_dir(trans, root,
path, location.objectid);
if (ret) {
kfree(name);
iput(inode);
goto out;
}
inc_nlink(inode);
ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
BTRFS_I(inode), name, name_len);
if (!ret)
ret = btrfs_run_delayed_items(trans);
kfree(name);
iput(inode);
if (ret)
goto out;
/* there might still be more names under this key
* check and repeat if required
*/
ret = btrfs_search_slot(NULL, root, dir_key, path,
0, 0);
if (ret == 0)
goto again;
ret = 0;
goto out;
} else if (IS_ERR(log_di)) {
kfree(name);
return PTR_ERR(log_di);
}
btrfs_release_path(log_path);
kfree(name);
ptr = (unsigned long)(di + 1);
ptr += name_len;
}
ret = 0;
out:
btrfs_release_path(path);
btrfs_release_path(log_path);
return ret;
}
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
const u64 ino)
{
struct btrfs_key search_key;
struct btrfs_path *log_path;
int i;
int nritems;
int ret;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_XATTR_ITEM_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
process_leaf:
nritems = btrfs_header_nritems(path->nodes[0]);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_key key;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
u32 total_size;
u32 cur;
btrfs_item_key_to_cpu(path->nodes[0], &key, i);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
ret = 0;
goto out;
}
di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
total_size = btrfs_item_size_nr(path->nodes[0], i);
cur = 0;
while (cur < total_size) {
u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
u32 this_len = sizeof(*di) + name_len + data_len;
char *name;
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(path->nodes[0], name,
(unsigned long)(di + 1), name_len);
log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
name, name_len, 0);
btrfs_release_path(log_path);
if (!log_di) {
/* Doesn't exist in log tree, so delete it. */
btrfs_release_path(path);
di = btrfs_lookup_xattr(trans, root, path, ino,
name, name_len, -1);
kfree(name);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
ASSERT(di);
ret = btrfs_delete_one_dir_name(trans, root,
path, di);
if (ret)
goto out;
btrfs_release_path(path);
search_key = key;
goto again;
}
kfree(name);
if (IS_ERR(log_di)) {
ret = PTR_ERR(log_di);
goto out;
}
cur += this_len;
di = (struct btrfs_dir_item *)((char *)di + this_len);
}
}
ret = btrfs_next_leaf(root, path);
if (ret > 0)
ret = 0;
else if (ret == 0)
goto process_leaf;
out:
btrfs_free_path(log_path);
btrfs_release_path(path);
return ret;
}
/*
* deletion replay happens before we copy any new directory items
* out of the log or out of backreferences from inodes. It
* scans the log to find ranges of keys that log is authoritative for,
* and then scans the directory to find items in those ranges that are
* not present in the log.
*
* Anything we don't find in the log is unlinked and removed from the
* directory.
*/
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
u64 dirid, int del_all)
{
u64 range_start;
u64 range_end;
int key_type = BTRFS_DIR_LOG_ITEM_KEY;
int ret = 0;
struct btrfs_key dir_key;
struct btrfs_key found_key;
struct btrfs_path *log_path;
struct inode *dir;
dir_key.objectid = dirid;
dir_key.type = BTRFS_DIR_ITEM_KEY;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
dir = read_one_inode(root, dirid);
/* it isn't an error if the inode isn't there, that can happen
* because we replay the deletes before we copy in the inode item
* from the log
*/
if (!dir) {
btrfs_free_path(log_path);
return 0;
}
again:
range_start = 0;
range_end = 0;
while (1) {
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
if (del_all)
range_end = (u64)-1;
else {
ret = find_dir_range(log, path, dirid, key_type,
&range_start, &range_end);
if (ret != 0)
break;
}
dir_key.offset = range_start;
while (1) {
int nritems;
ret = btrfs_search_slot(NULL, root, &dir_key, path,
0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret == 1)
break;
else if (ret < 0)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != dirid ||
found_key.type != dir_key.type)
goto next_type;
if (found_key.offset > range_end)
break;
ret = check_item_in_log(trans, root, log, path,
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
log_path, dir,
&found_key);
if (ret)
goto out;
if (found_key.offset == (u64)-1)
break;
dir_key.offset = found_key.offset + 1;
}
btrfs_release_path(path);
if (range_end == (u64)-1)
break;
range_start = range_end + 1;
}
next_type:
ret = 0;
if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
key_type = BTRFS_DIR_LOG_INDEX_KEY;
dir_key.type = BTRFS_DIR_INDEX_KEY;
btrfs_release_path(path);
goto again;
}
out:
btrfs_release_path(path);
btrfs_free_path(log_path);
iput(dir);
return ret;
}
/*
* the process_func used to replay items from the log tree. This
* gets called in two different stages. The first stage just looks
* for inodes and makes sure they are all copied into the subvolume.
*
* The second stage copies all the other item types from the log into
* the subvolume. The two stage approach is slower, but gets rid of
* lots of complexity around inodes referencing other inodes that exist
* only in the log (references come from either directory items or inode
* back refs).
*/
static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level)
{
int nritems;
struct btrfs_path *path;
struct btrfs_root *root = wc->replay_dest;
struct btrfs_key key;
int i;
int ret;
ret = btrfs_read_buffer(eb, gen, level, NULL);
if (ret)
return ret;
level = btrfs_header_level(eb);
if (level != 0)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
nritems = btrfs_header_nritems(eb);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
/* inode keys are done during the first stage */
if (key.type == BTRFS_INODE_ITEM_KEY &&
wc->stage == LOG_WALK_REPLAY_INODES) {
struct btrfs_inode_item *inode_item;
u32 mode;
inode_item = btrfs_item_ptr(eb, i,
struct btrfs_inode_item);
Btrfs: fix warning when replaying log after fsync of a tmpfile When replaying a log which contains a tmpfile (which necessarily has a link count of 0) we end up calling inc_nlink(), at fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like the following: [195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40 [195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1 [195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [195191.943726] RIP: 0010:inc_nlink+0x33/0x40 [195191.943728] RSP: 0018:ffffb96e425e3870 EFLAGS: 00010246 [195191.943730] RAX: 0000000000000000 RBX: ffff8c0d1e6af4f0 RCX: 0000000000000006 [195191.943731] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8c0d1e6af4f0 [195191.943731] RBP: 0000000000000097 R08: 0000000000000001 R09: 0000000000000000 [195191.943732] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb96e425e3a60 [195191.943733] R13: ffff8c0d10cff0c8 R14: ffff8c0d0d515348 R15: ffff8c0d78a1b3f8 [195191.943735] FS: 00007f570ee24480(0000) GS:ffff8c0dfb200000(0000) knlGS:0000000000000000 [195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [195191.943737] CR2: 00005593286277c8 CR3: 00000000bb8f2006 CR4: 00000000003606f0 [195191.943739] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [195191.943740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [195191.943741] Call Trace: [195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs] [195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs] [195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943825] walk_log_tree+0xae/0x1d0 [btrfs] [195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs] [195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs] [195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs] [195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs] [195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943899] ? pcpu_alloc+0x55b/0x7c0 [195191.943906] ? mount_fs+0x3b/0x140 [195191.943908] mount_fs+0x3b/0x140 [195191.943912] ? __init_waitqueue_head+0x36/0x50 [195191.943916] vfs_kern_mount+0x62/0x160 [195191.943927] btrfs_mount+0x134/0x890 [btrfs] [195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943938] ? pcpu_alloc+0x55b/0x7c0 [195191.943943] ? mount_fs+0x3b/0x140 [195191.943952] ? btrfs_remount+0x570/0x570 [btrfs] [195191.943954] mount_fs+0x3b/0x140 [195191.943956] ? __init_waitqueue_head+0x36/0x50 [195191.943960] vfs_kern_mount+0x62/0x160 [195191.943963] do_mount+0x1f9/0xd40 [195191.943967] ? memdup_user+0x4b/0x70 [195191.943971] ksys_mount+0x7e/0xd0 [195191.943974] __x64_sys_mount+0x21/0x30 [195191.943977] do_syscall_64+0x60/0x1b0 [195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe [195191.943983] RIP: 0033:0x7f570e4e524a [195191.943986] RSP: 002b:00007ffd83589478 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [195191.943989] RAX: ffffffffffffffda RBX: 0000563f335b2060 RCX: 00007f570e4e524a [195191.943990] RDX: 0000563f335b2240 RSI: 0000563f335b2280 RDI: 0000563f335b2260 [195191.943992] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020 [195191.943993] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000563f335b2260 [195191.943994] R13: 0000563f335b2240 R14: 0000000000000000 R15: 00000000ffffffff [195191.944002] irq event stamp: 8688 [195191.944010] hardirqs last enabled at (8687): [<ffffffff9cb004c3>] console_unlock+0x503/0x640 [195191.944012] hardirqs last disabled at (8688): [<ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c [195191.944018] softirqs last enabled at (8638): [<ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150 [195191.944020] softirqs last disabled at (8634): [<ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60 [195191.944022] ---[ end trace 5d6e873a9a0b811a ]--- This happens because the inode does not have the flag I_LINKABLE set, which is a runtime only flag, not meant to be persisted, set when the inode is created through open(2) if the flag O_EXCL is not passed to it. Except for the warning, there are no other consequences (like corruptions or metadata inconsistencies). Since it's pointless to replay a tmpfile as it would be deleted in a later phase of the log replay procedure (it has a link count of 0), fix this by not logging tmpfiles and if a tmpfile is found in a log (created by a kernel without this change), skip the replay of the inode. A test case for fstests follows soon. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.18+ Reported-by: Martin Steigerwald <martin@lichtvoll.de> Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-08 10:12:55 +00:00
/*
* If we have a tmpfile (O_TMPFILE) that got fsync'ed
* and never got linked before the fsync, skip it, as
* replaying it is pointless since it would be deleted
* later. We skip logging tmpfiles, but it's always
* possible we are replaying a log created with a kernel
* that used to log tmpfiles.
*/
if (btrfs_inode_nlink(eb, inode_item) == 0) {
wc->ignore_cur_inode = true;
continue;
} else {
wc->ignore_cur_inode = false;
}
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
ret = replay_xattr_deletes(wc->trans, root, log,
path, key.objectid);
if (ret)
break;
mode = btrfs_inode_mode(eb, inode_item);
if (S_ISDIR(mode)) {
ret = replay_dir_deletes(wc->trans,
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
root, log, path, key.objectid, 0);
if (ret)
break;
}
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
Btrfs: fix loss of prealloc extents past i_size after fsync log replay Currently if we allocate extents beyond an inode's i_size (through the fallocate system call) and then fsync the file, we log the extents but after a power failure we replay them and then immediately drop them. This behaviour happens since about 2009, commit c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log"), because it marks the inode as an orphan instead of dropping any extents beyond i_size before replaying logged extents, so after the log replay, and while the mount operation is still ongoing, we find the inode marked as an orphan and then perform a truncation (drop extents beyond the inode's i_size). Because the processing of orphan inodes is still done right after replaying the log and before the mount operation finishes, the intention of that commit does not make any sense (at least as of today). However reverting that behaviour is not enough, because we can not simply discard all extents beyond i_size and then replay logged extents, because we risk dropping extents beyond i_size created in past transactions, for example: add prealloc extent beyond i_size fsync - clears the flag BTRFS_INODE_NEEDS_FULL_SYNC from the inode transaction commit add another prealloc extent beyond i_size fsync - triggers the fast fsync path power failure In that scenario, we would drop the first extent and then replay the second one. To fix this just make sure that all prealloc extents beyond i_size are logged, and if we find too many (which is far from a common case), fallback to a full transaction commit (like we do when logging regular extents in the fast fsync path). Trivial reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 256K" /mnt/foo $ sync $ xfs_io -c "falloc -k 256K 1M" /mnt/foo $ xfs_io -c "fsync" /mnt/foo <power failure> # mount to replay log $ mount /dev/sdb /mnt # at this point the file only has one extent, at offset 0, size 256K A test case for fstests follows soon, covering multiple scenarios that involve adding prealloc extents with previous shrinking truncates and without such truncates. Fixes: c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-05 21:55:12 +00:00
/*
* Before replaying extents, truncate the inode to its
* size. We need to do it now and not after log replay
* because before an fsync we can have prealloc extents
* added beyond the inode's i_size. If we did it after,
* through orphan cleanup for example, we would drop
* those prealloc extents just after replaying them.
*/
if (S_ISREG(mode)) {
Btrfs: fix loss of prealloc extents past i_size after fsync log replay Currently if we allocate extents beyond an inode's i_size (through the fallocate system call) and then fsync the file, we log the extents but after a power failure we replay them and then immediately drop them. This behaviour happens since about 2009, commit c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log"), because it marks the inode as an orphan instead of dropping any extents beyond i_size before replaying logged extents, so after the log replay, and while the mount operation is still ongoing, we find the inode marked as an orphan and then perform a truncation (drop extents beyond the inode's i_size). Because the processing of orphan inodes is still done right after replaying the log and before the mount operation finishes, the intention of that commit does not make any sense (at least as of today). However reverting that behaviour is not enough, because we can not simply discard all extents beyond i_size and then replay logged extents, because we risk dropping extents beyond i_size created in past transactions, for example: add prealloc extent beyond i_size fsync - clears the flag BTRFS_INODE_NEEDS_FULL_SYNC from the inode transaction commit add another prealloc extent beyond i_size fsync - triggers the fast fsync path power failure In that scenario, we would drop the first extent and then replay the second one. To fix this just make sure that all prealloc extents beyond i_size are logged, and if we find too many (which is far from a common case), fallback to a full transaction commit (like we do when logging regular extents in the fast fsync path). Trivial reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 256K" /mnt/foo $ sync $ xfs_io -c "falloc -k 256K 1M" /mnt/foo $ xfs_io -c "fsync" /mnt/foo <power failure> # mount to replay log $ mount /dev/sdb /mnt # at this point the file only has one extent, at offset 0, size 256K A test case for fstests follows soon, covering multiple scenarios that involve adding prealloc extents with previous shrinking truncates and without such truncates. Fixes: c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-05 21:55:12 +00:00
struct inode *inode;
u64 from;
inode = read_one_inode(root, key.objectid);
if (!inode) {
ret = -EIO;
break;
}
from = ALIGN(i_size_read(inode),
root->fs_info->sectorsize);
ret = btrfs_drop_extents(wc->trans, root, inode,
from, (u64)-1, 1);
if (!ret) {
Btrfs: fix warning when replaying log after fsync of a tmpfile When replaying a log which contains a tmpfile (which necessarily has a link count of 0) we end up calling inc_nlink(), at fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like the following: [195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40 [195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1 [195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [195191.943726] RIP: 0010:inc_nlink+0x33/0x40 [195191.943728] RSP: 0018:ffffb96e425e3870 EFLAGS: 00010246 [195191.943730] RAX: 0000000000000000 RBX: ffff8c0d1e6af4f0 RCX: 0000000000000006 [195191.943731] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8c0d1e6af4f0 [195191.943731] RBP: 0000000000000097 R08: 0000000000000001 R09: 0000000000000000 [195191.943732] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb96e425e3a60 [195191.943733] R13: ffff8c0d10cff0c8 R14: ffff8c0d0d515348 R15: ffff8c0d78a1b3f8 [195191.943735] FS: 00007f570ee24480(0000) GS:ffff8c0dfb200000(0000) knlGS:0000000000000000 [195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [195191.943737] CR2: 00005593286277c8 CR3: 00000000bb8f2006 CR4: 00000000003606f0 [195191.943739] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [195191.943740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [195191.943741] Call Trace: [195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs] [195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs] [195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943825] walk_log_tree+0xae/0x1d0 [btrfs] [195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs] [195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs] [195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs] [195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs] [195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943899] ? pcpu_alloc+0x55b/0x7c0 [195191.943906] ? mount_fs+0x3b/0x140 [195191.943908] mount_fs+0x3b/0x140 [195191.943912] ? __init_waitqueue_head+0x36/0x50 [195191.943916] vfs_kern_mount+0x62/0x160 [195191.943927] btrfs_mount+0x134/0x890 [btrfs] [195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943938] ? pcpu_alloc+0x55b/0x7c0 [195191.943943] ? mount_fs+0x3b/0x140 [195191.943952] ? btrfs_remount+0x570/0x570 [btrfs] [195191.943954] mount_fs+0x3b/0x140 [195191.943956] ? __init_waitqueue_head+0x36/0x50 [195191.943960] vfs_kern_mount+0x62/0x160 [195191.943963] do_mount+0x1f9/0xd40 [195191.943967] ? memdup_user+0x4b/0x70 [195191.943971] ksys_mount+0x7e/0xd0 [195191.943974] __x64_sys_mount+0x21/0x30 [195191.943977] do_syscall_64+0x60/0x1b0 [195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe [195191.943983] RIP: 0033:0x7f570e4e524a [195191.943986] RSP: 002b:00007ffd83589478 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [195191.943989] RAX: ffffffffffffffda RBX: 0000563f335b2060 RCX: 00007f570e4e524a [195191.943990] RDX: 0000563f335b2240 RSI: 0000563f335b2280 RDI: 0000563f335b2260 [195191.943992] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020 [195191.943993] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000563f335b2260 [195191.943994] R13: 0000563f335b2240 R14: 0000000000000000 R15: 00000000ffffffff [195191.944002] irq event stamp: 8688 [195191.944010] hardirqs last enabled at (8687): [<ffffffff9cb004c3>] console_unlock+0x503/0x640 [195191.944012] hardirqs last disabled at (8688): [<ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c [195191.944018] softirqs last enabled at (8638): [<ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150 [195191.944020] softirqs last disabled at (8634): [<ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60 [195191.944022] ---[ end trace 5d6e873a9a0b811a ]--- This happens because the inode does not have the flag I_LINKABLE set, which is a runtime only flag, not meant to be persisted, set when the inode is created through open(2) if the flag O_EXCL is not passed to it. Except for the warning, there are no other consequences (like corruptions or metadata inconsistencies). Since it's pointless to replay a tmpfile as it would be deleted in a later phase of the log replay procedure (it has a link count of 0), fix this by not logging tmpfiles and if a tmpfile is found in a log (created by a kernel without this change), skip the replay of the inode. A test case for fstests follows soon. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.18+ Reported-by: Martin Steigerwald <martin@lichtvoll.de> Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-08 10:12:55 +00:00
/* Update the inode's nbytes. */
Btrfs: fix loss of prealloc extents past i_size after fsync log replay Currently if we allocate extents beyond an inode's i_size (through the fallocate system call) and then fsync the file, we log the extents but after a power failure we replay them and then immediately drop them. This behaviour happens since about 2009, commit c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log"), because it marks the inode as an orphan instead of dropping any extents beyond i_size before replaying logged extents, so after the log replay, and while the mount operation is still ongoing, we find the inode marked as an orphan and then perform a truncation (drop extents beyond the inode's i_size). Because the processing of orphan inodes is still done right after replaying the log and before the mount operation finishes, the intention of that commit does not make any sense (at least as of today). However reverting that behaviour is not enough, because we can not simply discard all extents beyond i_size and then replay logged extents, because we risk dropping extents beyond i_size created in past transactions, for example: add prealloc extent beyond i_size fsync - clears the flag BTRFS_INODE_NEEDS_FULL_SYNC from the inode transaction commit add another prealloc extent beyond i_size fsync - triggers the fast fsync path power failure In that scenario, we would drop the first extent and then replay the second one. To fix this just make sure that all prealloc extents beyond i_size are logged, and if we find too many (which is far from a common case), fallback to a full transaction commit (like we do when logging regular extents in the fast fsync path). Trivial reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 256K" /mnt/foo $ sync $ xfs_io -c "falloc -k 256K 1M" /mnt/foo $ xfs_io -c "fsync" /mnt/foo <power failure> # mount to replay log $ mount /dev/sdb /mnt # at this point the file only has one extent, at offset 0, size 256K A test case for fstests follows soon, covering multiple scenarios that involve adding prealloc extents with previous shrinking truncates and without such truncates. Fixes: c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-05 21:55:12 +00:00
ret = btrfs_update_inode(wc->trans,
root, inode);
}
iput(inode);
if (ret)
break;
}
ret = link_to_fixup_dir(wc->trans, root,
path, key.objectid);
if (ret)
break;
}
Btrfs: fix warning when replaying log after fsync of a tmpfile When replaying a log which contains a tmpfile (which necessarily has a link count of 0) we end up calling inc_nlink(), at fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like the following: [195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40 [195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1 [195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [195191.943726] RIP: 0010:inc_nlink+0x33/0x40 [195191.943728] RSP: 0018:ffffb96e425e3870 EFLAGS: 00010246 [195191.943730] RAX: 0000000000000000 RBX: ffff8c0d1e6af4f0 RCX: 0000000000000006 [195191.943731] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8c0d1e6af4f0 [195191.943731] RBP: 0000000000000097 R08: 0000000000000001 R09: 0000000000000000 [195191.943732] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb96e425e3a60 [195191.943733] R13: ffff8c0d10cff0c8 R14: ffff8c0d0d515348 R15: ffff8c0d78a1b3f8 [195191.943735] FS: 00007f570ee24480(0000) GS:ffff8c0dfb200000(0000) knlGS:0000000000000000 [195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [195191.943737] CR2: 00005593286277c8 CR3: 00000000bb8f2006 CR4: 00000000003606f0 [195191.943739] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [195191.943740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [195191.943741] Call Trace: [195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs] [195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs] [195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943825] walk_log_tree+0xae/0x1d0 [btrfs] [195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs] [195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs] [195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs] [195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs] [195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943899] ? pcpu_alloc+0x55b/0x7c0 [195191.943906] ? mount_fs+0x3b/0x140 [195191.943908] mount_fs+0x3b/0x140 [195191.943912] ? __init_waitqueue_head+0x36/0x50 [195191.943916] vfs_kern_mount+0x62/0x160 [195191.943927] btrfs_mount+0x134/0x890 [btrfs] [195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943938] ? pcpu_alloc+0x55b/0x7c0 [195191.943943] ? mount_fs+0x3b/0x140 [195191.943952] ? btrfs_remount+0x570/0x570 [btrfs] [195191.943954] mount_fs+0x3b/0x140 [195191.943956] ? __init_waitqueue_head+0x36/0x50 [195191.943960] vfs_kern_mount+0x62/0x160 [195191.943963] do_mount+0x1f9/0xd40 [195191.943967] ? memdup_user+0x4b/0x70 [195191.943971] ksys_mount+0x7e/0xd0 [195191.943974] __x64_sys_mount+0x21/0x30 [195191.943977] do_syscall_64+0x60/0x1b0 [195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe [195191.943983] RIP: 0033:0x7f570e4e524a [195191.943986] RSP: 002b:00007ffd83589478 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [195191.943989] RAX: ffffffffffffffda RBX: 0000563f335b2060 RCX: 00007f570e4e524a [195191.943990] RDX: 0000563f335b2240 RSI: 0000563f335b2280 RDI: 0000563f335b2260 [195191.943992] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020 [195191.943993] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000563f335b2260 [195191.943994] R13: 0000563f335b2240 R14: 0000000000000000 R15: 00000000ffffffff [195191.944002] irq event stamp: 8688 [195191.944010] hardirqs last enabled at (8687): [<ffffffff9cb004c3>] console_unlock+0x503/0x640 [195191.944012] hardirqs last disabled at (8688): [<ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c [195191.944018] softirqs last enabled at (8638): [<ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150 [195191.944020] softirqs last disabled at (8634): [<ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60 [195191.944022] ---[ end trace 5d6e873a9a0b811a ]--- This happens because the inode does not have the flag I_LINKABLE set, which is a runtime only flag, not meant to be persisted, set when the inode is created through open(2) if the flag O_EXCL is not passed to it. Except for the warning, there are no other consequences (like corruptions or metadata inconsistencies). Since it's pointless to replay a tmpfile as it would be deleted in a later phase of the log replay procedure (it has a link count of 0), fix this by not logging tmpfiles and if a tmpfile is found in a log (created by a kernel without this change), skip the replay of the inode. A test case for fstests follows soon. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.18+ Reported-by: Martin Steigerwald <martin@lichtvoll.de> Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-08 10:12:55 +00:00
if (wc->ignore_cur_inode)
continue;
if (key.type == BTRFS_DIR_INDEX_KEY &&
wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
if (wc->stage < LOG_WALK_REPLAY_ALL)
continue;
/* these keys are simply copied */
if (key.type == BTRFS_XATTR_ITEM_KEY) {
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
} else if (key.type == BTRFS_INODE_REF_KEY ||
key.type == BTRFS_INODE_EXTREF_KEY) {
ret = add_inode_ref(wc->trans, root, log, path,
eb, i, &key);
if (ret && ret != -ENOENT)
break;
ret = 0;
} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
ret = replay_one_extent(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
} else if (key.type == BTRFS_DIR_ITEM_KEY) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
}
btrfs_free_path(path);
return ret;
}
static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 root_owner;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
struct extent_buffer *parent;
u32 blocksize;
int ret = 0;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
while (*level > 0) {
struct btrfs_key first_key;
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
cur = path->nodes[*level];
WARN_ON(btrfs_header_level(cur) != *level);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
blocksize = fs_info->nodesize;
parent = path->nodes[*level];
root_owner = btrfs_header_owner(parent);
next = btrfs_find_create_tree_block(fs_info, bytenr);
if (IS_ERR(next))
return PTR_ERR(next);
if (*level == 1) {
ret = wc->process_func(root, next, wc, ptr_gen,
*level - 1);
if (ret) {
free_extent_buffer(next);
return ret;
}
path->slots[*level]++;
if (wc->free) {
ret = btrfs_read_buffer(next, ptr_gen,
*level - 1, &first_key);
if (ret) {
free_extent_buffer(next);
return ret;
}
if (trans) {
btrfs_tree_lock(next);
btrfs_set_lock_blocking_write(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
}
WARN_ON(root_owner !=
BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_and_pin_reserved_extent(
fs_info, bytenr,
blocksize);
if (ret) {
free_extent_buffer(next);
return ret;
}
}
free_extent_buffer(next);
continue;
}
ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key);
if (ret) {
free_extent_buffer(next);
return ret;
}
WARN_ON(*level <= 0);
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
WARN_ON(*level < 0);
WARN_ON(*level >= BTRFS_MAX_LEVEL);
path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
cond_resched();
return 0;
}
static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 root_owner;
int i;
int slot;
int ret;
for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
return 0;
} else {
struct extent_buffer *parent;
if (path->nodes[*level] == root->node)
parent = path->nodes[*level];
else
parent = path->nodes[*level + 1];
root_owner = btrfs_header_owner(parent);
ret = wc->process_func(root, path->nodes[*level], wc,
btrfs_header_generation(path->nodes[*level]),
*level);
if (ret)
return ret;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[*level];
if (trans) {
btrfs_tree_lock(next);
btrfs_set_lock_blocking_write(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
}
WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_and_pin_reserved_extent(
fs_info,
path->nodes[*level]->start,
path->nodes[*level]->len);
if (ret)
return ret;
}
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
static int walk_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int orig_level;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
level = btrfs_header_level(log->node);
orig_level = level;
path->nodes[level] = log->node;
extent_buffer_get(log->node);
path->slots[level] = 0;
while (1) {
wret = walk_down_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
wret = walk_up_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
}
/* was the root node processed? if not, catch it here */
if (path->nodes[orig_level]) {
ret = wc->process_func(log, path->nodes[orig_level], wc,
btrfs_header_generation(path->nodes[orig_level]),
orig_level);
if (ret)
goto out;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[orig_level];
if (trans) {
btrfs_tree_lock(next);
btrfs_set_lock_blocking_write(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
}
WARN_ON(log->root_key.objectid !=
BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_free_and_pin_reserved_extent(fs_info,
next->start, next->len);
if (ret)
goto out;
}
}
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function to update the item for a given subvolumes log root
* in the tree of log roots
*/
static int update_log_root(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret;
if (log->log_transid == 1) {
/* insert root item on the first sync */
ret = btrfs_insert_root(trans, fs_info->log_root_tree,
&log->root_key, &log->root_item);
} else {
ret = btrfs_update_root(trans, fs_info->log_root_tree,
&log->root_key, &log->root_item);
}
return ret;
}
static void wait_log_commit(struct btrfs_root *root, int transid)
{
DEFINE_WAIT(wait);
int index = transid % 2;
/*
* we only allow two pending log transactions at a time,
* so we know that if ours is more than 2 older than the
* current transaction, we're done
*/
for (;;) {
prepare_to_wait(&root->log_commit_wait[index],
&wait, TASK_UNINTERRUPTIBLE);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
if (!(root->log_transid_committed < transid &&
atomic_read(&root->log_commit[index])))
break;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
mutex_unlock(&root->log_mutex);
schedule();
mutex_lock(&root->log_mutex);
}
finish_wait(&root->log_commit_wait[index], &wait);
}
static void wait_for_writer(struct btrfs_root *root)
{
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(&root->log_writer_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (!atomic_read(&root->log_writers))
break;
mutex_unlock(&root->log_mutex);
schedule();
Btrfs: fix scheduler warning when syncing log We try to lock a mutex while the current task state is not TASK_RUNNING, which results in the following warning when CONFIG_DEBUG_LOCK_ALLOC=y: [30736.772501] ------------[ cut here ]------------ [30736.774545] WARNING: CPU: 9 PID: 19972 at kernel/sched/core.c:7300 __might_sleep+0x8b/0xa8() [30736.783453] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff8107499b>] prepare_to_wait+0x43/0x89 [30736.786261] Modules linked in: dm_flakey dm_mod crc32c_generic btrfs xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop parport_pc psmouse parport pcspkr microcode serio_raw evdev processor thermal_sys i2c_piix4 i2c_core button ext4 crc16 jbd2 mbcache sg sr_mod cdrom sd_mod ata_generic virtio_scsi floppy ata_piix libata virtio_pci virtio_ring e1000 virtio scsi_mod [30736.794323] CPU: 9 PID: 19972 Comm: fsstress Not tainted 3.19.0-rc7-btrfs-next-5+ #1 [30736.795821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [30736.798788] 0000000000000009 ffff88042743fbd8 ffffffff814248ed ffff88043d32f2d8 [30736.800504] ffff88042743fc28 ffff88042743fc18 ffffffff81045338 0000000000000001 [30736.802131] ffffffff81064514 ffffffff817c52d1 000000000000026d 0000000000000000 [30736.803676] Call Trace: [30736.804256] [<ffffffff814248ed>] dump_stack+0x4c/0x65 [30736.805245] [<ffffffff81045338>] warn_slowpath_common+0xa1/0xbb [30736.806360] [<ffffffff81064514>] ? __might_sleep+0x8b/0xa8 [30736.807391] [<ffffffff81045398>] warn_slowpath_fmt+0x46/0x48 [30736.808511] [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89 [30736.809620] [<ffffffff8107499b>] ? prepare_to_wait+0x43/0x89 [30736.810691] [<ffffffff81064514>] __might_sleep+0x8b/0xa8 [30736.811703] [<ffffffff81426eaf>] mutex_lock_nested+0x2f/0x3a0 [30736.812889] [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab [30736.814138] [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf [30736.819878] [<ffffffffa038cfff>] wait_for_writer.isra.12+0x91/0xaa [btrfs] [30736.821260] [<ffffffff810748bd>] ? signal_pending_state+0x31/0x31 [30736.822410] [<ffffffffa0391f0a>] btrfs_sync_log+0x160/0x947 [btrfs] [30736.823574] [<ffffffff8107bfa1>] ? trace_hardirqs_on_caller+0x18f/0x1ab [30736.824847] [<ffffffff8107bfca>] ? trace_hardirqs_on+0xd/0xf [30736.825972] [<ffffffffa036e555>] btrfs_sync_file+0x2b0/0x319 [btrfs] [30736.827684] [<ffffffff8117901a>] vfs_fsync_range+0x21/0x23 [30736.828932] [<ffffffff81179038>] vfs_fsync+0x1c/0x1e [30736.829917] [<ffffffff8117928b>] do_fsync+0x34/0x4e [30736.830862] [<ffffffff811794b3>] SyS_fsync+0x10/0x14 [30736.831819] [<ffffffff8142a512>] system_call_fastpath+0x12/0x17 [30736.832982] ---[ end trace c0b57df60d32ae5c ]--- Fix this my acquiring the mutex after calling finish_wait(), which sets the task's state to TASK_RUNNING. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-11 11:12:39 +00:00
mutex_lock(&root->log_mutex);
}
finish_wait(&root->log_writer_wait, &wait);
}
static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
if (!ctx)
return;
mutex_lock(&root->log_mutex);
list_del_init(&ctx->list);
mutex_unlock(&root->log_mutex);
}
/*
* Invoked in log mutex context, or be sure there is no other task which
* can access the list.
*/
static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
int index, int error)
{
struct btrfs_log_ctx *ctx;
struct btrfs_log_ctx *safe;
list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
list_del_init(&ctx->list);
ctx->log_ret = error;
}
INIT_LIST_HEAD(&root->log_ctxs[index]);
}
/*
* btrfs_sync_log does sends a given tree log down to the disk and
* updates the super blocks to record it. When this call is done,
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
* you know that any inodes previously logged are safely on disk only
* if it returns 0.
*
* Any other return value means you need to call btrfs_commit_transaction.
* Some of the edge cases for fsyncing directories that have had unlinks
* or renames done in the past mean that sometimes the only safe
* fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
* that has happened.
*/
int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_log_ctx *ctx)
{
int index1;
int index2;
int mark;
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *log = root->log_root;
struct btrfs_root *log_root_tree = fs_info->log_root_tree;
int log_transid = 0;
struct btrfs_log_ctx root_log_ctx;
struct blk_plug plug;
mutex_lock(&root->log_mutex);
log_transid = ctx->log_transid;
if (root->log_transid_committed >= log_transid) {
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
index1 = log_transid % 2;
if (atomic_read(&root->log_commit[index1])) {
wait_log_commit(root, log_transid);
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
ASSERT(log_transid == root->log_transid);
atomic_set(&root->log_commit[index1], 1);
/* wait for previous tree log sync to complete */
if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
wait_log_commit(root, log_transid - 1);
while (1) {
int batch = atomic_read(&root->log_batch);
/* when we're on an ssd, just kick the log commit out */
if (!btrfs_test_opt(fs_info, SSD) &&
test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
mutex_unlock(&root->log_mutex);
schedule_timeout_uninterruptible(1);
mutex_lock(&root->log_mutex);
}
wait_for_writer(root);
if (batch == atomic_read(&root->log_batch))
break;
}
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/* bail out if we need to do a full commit */
if (btrfs_need_log_full_commit(trans)) {
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
ret = -EAGAIN;
mutex_unlock(&root->log_mutex);
goto out;
}
if (log_transid % 2 == 0)
mark = EXTENT_DIRTY;
else
mark = EXTENT_NEW;
/* we start IO on all the marked extents here, but we don't actually
* wait for them until later.
*/
blk_start_plug(&plug);
ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
if (ret) {
blk_finish_plug(&plug);
btrfs_abort_transaction(trans, ret);
btrfs_set_log_full_commit(trans);
mutex_unlock(&root->log_mutex);
goto out;
}
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
btrfs_set_root_node(&log->root_item, log->node);
root->log_transid++;
log->log_transid = root->log_transid;
root->log_start_pid = 0;
Btrfs: fix race updating log root item during fsync When syncing the log, the final phase of a fsync operation, we need to either create a log root's item or update the existing item in the log tree of log roots, and that depends on the current value of the log root's log_transid - if it's 1 we need to create the log root item, otherwise it must exist already and we update it. Since there is no synchronization between updating the log_transid and checking it for deciding whether the log root's item needs to be created or updated, we end up with a tiny race window that results in attempts to update the item to fail because the item was not yet created: CPU 1 CPU 2 btrfs_sync_log() lock root->log_mutex set log root's log_transid to 1 unlock root->log_mutex btrfs_sync_log() lock root->log_mutex sets log root's log_transid to 2 unlock root->log_mutex update_log_root() sees log root's log_transid with a value of 2 calls btrfs_update_root(), which fails with -EUCLEAN and causes transaction abort Until recently the race lead to a BUG_ON at btrfs_update_root(), but after the recent commit 7ac1e464c4d47 ("btrfs: Don't panic when we can't find a root key") we just abort the current transaction. A sample trace of the BUG_ON() on a SLE12 kernel: ------------[ cut here ]------------ kernel BUG at ../fs/btrfs/root-tree.c:157! Oops: Exception in kernel mode, sig: 5 [#1] SMP NR_CPUS=2048 NUMA pSeries (...) Supported: Yes, External CPU: 78 PID: 76303 Comm: rtas_errd Tainted: G X 4.4.156-94.57-default #1 task: c00000ffa906d010 ti: c00000ff42b08000 task.ti: c00000ff42b08000 NIP: d000000036ae5cdc LR: d000000036ae5cd8 CTR: 0000000000000000 REGS: c00000ff42b0b860 TRAP: 0700 Tainted: G X (4.4.156-94.57-default) MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 22444484 XER: 20000000 CFAR: d000000036aba66c SOFTE: 1 GPR00: d000000036ae5cd8 c00000ff42b0bae0 d000000036bda220 0000000000000054 GPR04: 0000000000000001 0000000000000000 c00007ffff8d37c8 0000000000000000 GPR08: c000000000e19c00 0000000000000000 0000000000000000 3736343438312079 GPR12: 3930373337303434 c000000007a3a800 00000000007fffff 0000000000000023 GPR16: c00000ffa9d26028 c00000ffa9d261f8 0000000000000010 c00000ffa9d2ab28 GPR20: c00000ff42b0bc48 0000000000000001 c00000ff9f0d9888 0000000000000001 GPR24: c00000ffa9d26000 c00000ffa9d261e8 c00000ffa9d2a800 c00000ff9f0d9888 GPR28: c00000ffa9d26028 c00000ffa9d2aa98 0000000000000001 c00000ffa98f5b20 NIP [d000000036ae5cdc] btrfs_update_root+0x25c/0x4e0 [btrfs] LR [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] Call Trace: [c00000ff42b0bae0] [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] (unreliable) [c00000ff42b0bba0] [d000000036b53610] btrfs_sync_log+0x2d0/0xc60 [btrfs] [c00000ff42b0bce0] [d000000036b1785c] btrfs_sync_file+0x44c/0x4e0 [btrfs] [c00000ff42b0bd80] [c00000000032e300] vfs_fsync_range+0x70/0x120 [c00000ff42b0bdd0] [c00000000032e44c] do_fsync+0x5c/0xb0 [c00000ff42b0be10] [c00000000032e8dc] SyS_fdatasync+0x2c/0x40 [c00000ff42b0be30] [c000000000009488] system_call+0x3c/0x100 Instruction dump: 7f43d378 4bffebb9 60000000 88d90008 3d220000 e8b90000 3b390009 e87a01f0 e8898e08 e8f90000 4bfd48e5 60000000 <0fe00000> e95b0060 39200004 394a0ea0 ---[ end trace 8f2dc8f919cabab8 ]--- So fix this by doing the check of log_transid and updating or creating the log root's item while holding the root's log_mutex. Fixes: 7237f1833601d ("Btrfs: fix tree logs parallel sync") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-15 15:03:17 +00:00
/*
* Update or create log root item under the root's log_mutex to prevent
* races with concurrent log syncs that can lead to failure to update
* log root item because it was not created yet.
*/
ret = update_log_root(trans, log);
/*
* IO has been started, blocks of the log tree have WRITTEN flag set
* in their headers. new modifications of the log will be written to
* new positions. so it's safe to allow log writers to go in.
*/
mutex_unlock(&root->log_mutex);
Btrfs: fix lockdep warning on deadlock against an inode's log mutex Commit 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink"), which landed in 4.8-rc2, introduced a possibility for a deadlock due to double locking of an inode's log mutex by the same task, which lockdep reports with: [23045.433975] ============================================= [23045.434748] [ INFO: possible recursive locking detected ] [23045.435426] 4.7.0-rc6-btrfs-next-34+ #1 Not tainted [23045.436044] --------------------------------------------- [23045.436044] xfs_io/3688 is trying to acquire lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] but task is already holding lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] other info that might help us debug this: [23045.436044] Possible unsafe locking scenario: [23045.436044] CPU0 [23045.436044] ---- [23045.436044] lock(&ei->log_mutex); [23045.436044] lock(&ei->log_mutex); [23045.436044] *** DEADLOCK *** [23045.436044] May be due to missing lock nesting notation [23045.436044] 3 locks held by xfs_io/3688: [23045.436044] #0: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffffa035f2ae>] btrfs_sync_file+0x14e/0x425 [btrfs] [23045.436044] #1: (sb_internal#2){.+.+.+}, at: [<ffffffff8118446b>] __sb_start_write+0x5f/0xb0 [23045.436044] #2: (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] stack backtrace: [23045.436044] CPU: 4 PID: 3688 Comm: xfs_io Not tainted 4.7.0-rc6-btrfs-next-34+ #1 [23045.436044] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [23045.436044] 0000000000000000 ffff88022f5f7860 ffffffff8127074d ffffffff82a54b70 [23045.436044] ffffffff82a54b70 ffff88022f5f7920 ffffffff81092897 ffff880228015d68 [23045.436044] 0000000000000000 ffffffff82a54b70 ffffffff829c3f00 ffff880228015d68 [23045.436044] Call Trace: [23045.436044] [<ffffffff8127074d>] dump_stack+0x67/0x90 [23045.436044] [<ffffffff81092897>] __lock_acquire+0xcbb/0xe4e [23045.436044] [<ffffffff8109155f>] ? mark_lock+0x24/0x201 [23045.436044] [<ffffffff8109179a>] ? mark_held_locks+0x5e/0x74 [23045.436044] [<ffffffff81092de0>] lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffff81092de0>] ? lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff814a51a4>] mutex_lock_nested+0x77/0x3a7 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa039705e>] ? btrfs_release_delayed_node+0xb/0xd [btrfs] [23045.436044] [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff810a0ed1>] ? vprintk_emit+0x453/0x465 [23045.436044] [<ffffffffa0385a61>] btrfs_log_inode+0x66e/0xc95 [btrfs] [23045.436044] [<ffffffffa03c084d>] log_new_dir_dentries+0x26c/0x359 [btrfs] [23045.436044] [<ffffffffa03865aa>] btrfs_log_inode_parent+0x4a6/0x628 [btrfs] [23045.436044] [<ffffffffa0387552>] btrfs_log_dentry_safe+0x5a/0x75 [btrfs] [23045.436044] [<ffffffffa035f464>] btrfs_sync_file+0x304/0x425 [btrfs] [23045.436044] [<ffffffff811acaf4>] vfs_fsync_range+0x8c/0x9e [23045.436044] [<ffffffff811acb22>] vfs_fsync+0x1c/0x1e [23045.436044] [<ffffffff811acc79>] do_fsync+0x31/0x4a [23045.436044] [<ffffffff811ace99>] SyS_fsync+0x10/0x14 [23045.436044] [<ffffffff814a88e5>] entry_SYSCALL_64_fastpath+0x18/0xa8 [23045.436044] [<ffffffff8108f039>] ? trace_hardirqs_off_caller+0x3f/0xaa An example reproducer for this is: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ sync $ mv /mnt/dir/foo /mnt/dir/bar $ touch /mnt/dir/foo $ xfs_io -c "fsync" /mnt/dir/bar This is because while logging the inode of file bar we end up logging its parent directory (since its inode has an unlink_trans field matching the current transaction id due to the rename operation), which in turn logs the inodes for all its new dentries, so that the new inode for the new file named foo gets logged which in turn triggered another logging attempt for the inode we are fsync'ing, since that inode had an old name that corresponds to the name of the new inode. So fix this by ensuring that when logging the inode for a new dentry that has a name matching an old name of some other inode, we don't log again the original inode that we are fsync'ing. Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-23 20:13:51 +00:00
btrfs_init_log_ctx(&root_log_ctx, NULL);
mutex_lock(&log_root_tree->log_mutex);
atomic_inc(&log_root_tree->log_batch);
atomic_inc(&log_root_tree->log_writers);
index2 = log_root_tree->log_transid % 2;
list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
root_log_ctx.log_transid = log_root_tree->log_transid;
mutex_unlock(&log_root_tree->log_mutex);
mutex_lock(&log_root_tree->log_mutex);
if (atomic_dec_and_test(&log_root_tree->log_writers)) {
/* atomic_dec_and_test implies a barrier */
cond_wake_up_nomb(&log_root_tree->log_writer_wait);
}
if (ret) {
if (!list_empty(&root_log_ctx.list))
list_del_init(&root_log_ctx.list);
blk_finish_plug(&plug);
btrfs_set_log_full_commit(trans);
if (ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out;
}
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
ret = -EAGAIN;
goto out;
}
if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
blk_finish_plug(&plug);
list_del_init(&root_log_ctx.list);
mutex_unlock(&log_root_tree->log_mutex);
ret = root_log_ctx.log_ret;
goto out;
}
index2 = root_log_ctx.log_transid % 2;
if (atomic_read(&log_root_tree->log_commit[index2])) {
blk_finish_plug(&plug);
ret = btrfs_wait_tree_log_extents(log, mark);
wait_log_commit(log_root_tree,
root_log_ctx.log_transid);
mutex_unlock(&log_root_tree->log_mutex);
if (!ret)
ret = root_log_ctx.log_ret;
goto out;
}
ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
atomic_set(&log_root_tree->log_commit[index2], 1);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
wait_log_commit(log_root_tree,
root_log_ctx.log_transid - 1);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
}
wait_for_writer(log_root_tree);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* now that we've moved on to the tree of log tree roots,
* check the full commit flag again
*/
if (btrfs_need_log_full_commit(trans)) {
blk_finish_plug(&plug);
btrfs_wait_tree_log_extents(log, mark);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
mutex_unlock(&log_root_tree->log_mutex);
ret = -EAGAIN;
goto out_wake_log_root;
}
ret = btrfs_write_marked_extents(fs_info,
&log_root_tree->dirty_log_pages,
EXTENT_DIRTY | EXTENT_NEW);
blk_finish_plug(&plug);
if (ret) {
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
ret = btrfs_wait_tree_log_extents(log, mark);
if (!ret)
ret = btrfs_wait_tree_log_extents(log_root_tree,
EXTENT_NEW | EXTENT_DIRTY);
if (ret) {
btrfs_set_log_full_commit(trans);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
btrfs_set_super_log_root(fs_info->super_for_commit,
log_root_tree->node->start);
btrfs_set_super_log_root_level(fs_info->super_for_commit,
btrfs_header_level(log_root_tree->node));
log_root_tree->log_transid++;
mutex_unlock(&log_root_tree->log_mutex);
/*
* Nobody else is going to jump in and write the ctree
* super here because the log_commit atomic below is protecting
* us. We must be called with a transaction handle pinning
* the running transaction open, so a full commit can't hop
* in and cause problems either.
*/
ret = write_all_supers(fs_info, 1);
if (ret) {
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
goto out_wake_log_root;
}
mutex_lock(&root->log_mutex);
if (root->last_log_commit < log_transid)
root->last_log_commit = log_transid;
mutex_unlock(&root->log_mutex);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
out_wake_log_root:
mutex_lock(&log_root_tree->log_mutex);
btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
log_root_tree->log_transid_committed++;
atomic_set(&log_root_tree->log_commit[index2], 0);
mutex_unlock(&log_root_tree->log_mutex);
/*
* The barrier before waitqueue_active (in cond_wake_up) is needed so
* all the updates above are seen by the woken threads. It might not be
* necessary, but proving that seems to be hard.
*/
cond_wake_up(&log_root_tree->log_commit_wait[index2]);
out:
mutex_lock(&root->log_mutex);
btrfs_remove_all_log_ctxs(root, index1, ret);
root->log_transid_committed++;
atomic_set(&root->log_commit[index1], 0);
mutex_unlock(&root->log_mutex);
/*
* The barrier before waitqueue_active (in cond_wake_up) is needed so
* all the updates above are seen by the woken threads. It might not be
* necessary, but proving that seems to be hard.
*/
cond_wake_up(&root->log_commit_wait[index1]);
return ret;
}
static void free_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
int ret;
struct walk_control wc = {
.free = 1,
.process_func = process_one_buffer
};
ret = walk_log_tree(trans, log, &wc);
btrfs: fix error handling in free_log_tree When we hit an I/O error in free_log_tree->walk_log_tree during file system shutdown we can crash due to there not being a valid transaction handle. Use btrfs_handle_fs_error when there's no transaction handle to use. BUG: unable to handle kernel NULL pointer dereference at 0000000000000060 IP: free_log_tree+0xd2/0x140 [btrfs] PGD 0 P4D 0 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI Modules linked in: <modules> CPU: 2 PID: 23544 Comm: umount Tainted: G W 4.12.14-kvmsmall #9 SLE15 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 task: ffff96bfd3478880 task.stack: ffffa7cf40d78000 RIP: 0010:free_log_tree+0xd2/0x140 [btrfs] RSP: 0018:ffffa7cf40d7bd10 EFLAGS: 00010282 RAX: 00000000fffffffb RBX: 00000000fffffffb RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffff96c02f07d4c8 RDI: 0000000000000282 RBP: ffff96c013cf1000 R08: ffff96c02f07d4c8 R09: ffff96c02f07d4d0 R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 R13: ffff96c005e800c0 R14: ffffa7cf40d7bdb8 R15: 0000000000000000 FS: 00007f17856bcfc0(0000) GS:ffff96c03f600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000060 CR3: 0000000045ed6002 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? wait_for_writer+0xb0/0xb0 [btrfs] btrfs_free_log+0x17/0x30 [btrfs] btrfs_drop_and_free_fs_root+0x9a/0xe0 [btrfs] btrfs_free_fs_roots+0xc0/0x130 [btrfs] ? wait_for_completion+0xf2/0x100 close_ctree+0xea/0x2e0 [btrfs] ? kthread_stop+0x161/0x260 generic_shutdown_super+0x6c/0x120 kill_anon_super+0xe/0x20 btrfs_kill_super+0x13/0x100 [btrfs] deactivate_locked_super+0x3f/0x70 cleanup_mnt+0x3b/0x70 task_work_run+0x78/0x90 exit_to_usermode_loop+0x77/0xa6 do_syscall_64+0x1c5/0x1e0 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f1784f90827 RSP: 002b:00007ffdeeb03118 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000556a60c62970 RCX: 00007f1784f90827 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556a60c62b50 RBP: 0000000000000000 R08: 0000000000000005 R09: 00000000ffffffff R10: 0000556a60c63900 R11: 0000000000000246 R12: 0000556a60c62b50 R13: 00007f17854a81c4 R14: 0000000000000000 R15: 0000000000000000 RIP: free_log_tree+0xd2/0x140 [btrfs] RSP: ffffa7cf40d7bd10 CR2: 0000000000000060 Fixes: 681ae50917df9 ("Btrfs: cleanup reserved space when freeing tree log on error") CC: <stable@vger.kernel.org> # v3.13 Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-09-06 20:59:33 +00:00
if (ret) {
if (trans)
btrfs_abort_transaction(trans, ret);
else
btrfs_handle_fs_error(log->fs_info, ret, NULL);
}
clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
free_extent_buffer(log->node);
kfree(log);
}
/*
* free all the extents used by the tree log. This should be called
* at commit time of the full transaction
*/
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
{
if (root->log_root) {
free_log_tree(trans, root->log_root);
root->log_root = NULL;
}
return 0;
}
int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
if (fs_info->log_root_tree) {
free_log_tree(trans, fs_info->log_root_tree);
fs_info->log_root_tree = NULL;
}
return 0;
}
Btrfs: fix fsync not persisting dentry deletions due to inode evictions In order to avoid searches on a log tree when unlinking an inode, we check if the inode being unlinked was logged in the current transaction, as well as the inode of its parent directory. When any of the inodes are logged, we proceed to delete directory items and inode reference items from the log, to ensure that if a subsequent fsync of only the inode being unlinked or only of the parent directory when the other is not fsync'ed as well, does not result in the entry still existing after a power failure. That check however is not reliable when one of the inodes involved (the one being unlinked or its parent directory's inode) is evicted, since the logged_trans field is transient, that is, it is not stored on disk, so it is lost when the inode is evicted and loaded into memory again (which is set to zero on load). As a consequence the checks currently being done by btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always return true if the inode was evicted before, regardless of the inode having been logged or not before (and in the current transaction), this results in the dentry being unlinked still existing after a log replay if after the unlink operation only one of the inodes involved is fsync'ed. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ xfs_io -c fsync /mnt/dir/foo # Keep an open file descriptor on our directory while we evict inodes. # We just want to evict the file's inode, the directory's inode must not # be evicted. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time to background process to chdir to our test # directory. $ sleep 0.5 # Trigger eviction of the file's inode. $ echo 2 > /proc/sys/vm/drop_caches # Unlink our file and fsync the parent directory. After a power failure # we don't expect to see the file anymore, since we fsync'ed the parent # directory. $ rm -f $SCRATCH_MNT/dir/foo $ xfs_io -c fsync /mnt/dir <power failure> $ mount /dev/sdb /mnt $ ls /mnt/dir foo $ --> file still there, unlink not persisted despite explicit fsync on dir Fix this by checking if the inode has the full_sync bit set in its runtime flags as well, since that bit is set everytime an inode is loaded from disk, or for other less common cases such as after a shrinking truncate or failure to allocate extent maps for holes, and gets cleared after the first fsync. Also consider the inode as possibly logged only if it was last modified in the current transaction (besides having the full_fsync flag set). Fixes: 3a5f1d458ad161 ("Btrfs: Optimize btree walking while logging inodes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-19 12:05:39 +00:00
/*
* Check if an inode was logged in the current transaction. We can't always rely
* on an inode's logged_trans value, because it's an in-memory only field and
* therefore not persisted. This means that its value is lost if the inode gets
* evicted and loaded again from disk (in which case it has a value of 0, and
* certainly it is smaller then any possible transaction ID), when that happens
* the full_sync flag is set in the inode's runtime flags, so on that case we
* assume eviction happened and ignore the logged_trans value, assuming the
* worst case, that the inode was logged before in the current transaction.
*/
static bool inode_logged(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
if (inode->logged_trans == trans->transid)
return true;
if (inode->last_trans == trans->transid &&
test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
!test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
return true;
return false;
}
/*
* If both a file and directory are logged, and unlinks or renames are
* mixed in, we have a few interesting corners:
*
* create file X in dir Y
* link file X to X.link in dir Y
* fsync file X
* unlink file X but leave X.link
* fsync dir Y
*
* After a crash we would expect only X.link to exist. But file X
* didn't get fsync'd again so the log has back refs for X and X.link.
*
* We solve this by removing directory entries and inode backrefs from the
* log when a file that was logged in the current transaction is
* unlinked. Any later fsync will include the updated log entries, and
* we'll be able to reconstruct the proper directory items from backrefs.
*
* This optimizations allows us to avoid relogging the entire inode
* or the entire directory.
*/
int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *dir, u64 index)
{
struct btrfs_root *log;
struct btrfs_dir_item *di;
struct btrfs_path *path;
int ret;
int err = 0;
int bytes_del = 0;
u64 dir_ino = btrfs_ino(dir);
Btrfs: fix fsync not persisting dentry deletions due to inode evictions In order to avoid searches on a log tree when unlinking an inode, we check if the inode being unlinked was logged in the current transaction, as well as the inode of its parent directory. When any of the inodes are logged, we proceed to delete directory items and inode reference items from the log, to ensure that if a subsequent fsync of only the inode being unlinked or only of the parent directory when the other is not fsync'ed as well, does not result in the entry still existing after a power failure. That check however is not reliable when one of the inodes involved (the one being unlinked or its parent directory's inode) is evicted, since the logged_trans field is transient, that is, it is not stored on disk, so it is lost when the inode is evicted and loaded into memory again (which is set to zero on load). As a consequence the checks currently being done by btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always return true if the inode was evicted before, regardless of the inode having been logged or not before (and in the current transaction), this results in the dentry being unlinked still existing after a log replay if after the unlink operation only one of the inodes involved is fsync'ed. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ xfs_io -c fsync /mnt/dir/foo # Keep an open file descriptor on our directory while we evict inodes. # We just want to evict the file's inode, the directory's inode must not # be evicted. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time to background process to chdir to our test # directory. $ sleep 0.5 # Trigger eviction of the file's inode. $ echo 2 > /proc/sys/vm/drop_caches # Unlink our file and fsync the parent directory. After a power failure # we don't expect to see the file anymore, since we fsync'ed the parent # directory. $ rm -f $SCRATCH_MNT/dir/foo $ xfs_io -c fsync /mnt/dir <power failure> $ mount /dev/sdb /mnt $ ls /mnt/dir foo $ --> file still there, unlink not persisted despite explicit fsync on dir Fix this by checking if the inode has the full_sync bit set in its runtime flags as well, since that bit is set everytime an inode is loaded from disk, or for other less common cases such as after a shrinking truncate or failure to allocate extent maps for holes, and gets cleared after the first fsync. Also consider the inode as possibly logged only if it was last modified in the current transaction (besides having the full_fsync flag set). Fixes: 3a5f1d458ad161 ("Btrfs: Optimize btree walking while logging inodes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-19 12:05:39 +00:00
if (!inode_logged(trans, dir))
return 0;
ret = join_running_log_trans(root);
if (ret)
return 0;
mutex_lock(&dir->log_mutex);
log = root->log_root;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out_unlock;
}
di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
name, name_len, -1);
if (IS_ERR(di)) {
err = PTR_ERR(di);
goto fail;
}
if (di) {
ret = btrfs_delete_one_dir_name(trans, log, path, di);
bytes_del += name_len;
if (ret) {
err = ret;
goto fail;
}
}
btrfs_release_path(path);
di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
index, name, name_len, -1);
if (IS_ERR(di)) {
err = PTR_ERR(di);
goto fail;
}
if (di) {
ret = btrfs_delete_one_dir_name(trans, log, path, di);
bytes_del += name_len;
if (ret) {
err = ret;
goto fail;
}
}
/* update the directory size in the log to reflect the names
* we have removed
*/
if (bytes_del) {
struct btrfs_key key;
key.objectid = dir_ino;
key.offset = 0;
key.type = BTRFS_INODE_ITEM_KEY;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (ret == 0) {
struct btrfs_inode_item *item;
u64 i_size;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
i_size = btrfs_inode_size(path->nodes[0], item);
if (i_size > bytes_del)
i_size -= bytes_del;
else
i_size = 0;
btrfs_set_inode_size(path->nodes[0], item, i_size);
btrfs_mark_buffer_dirty(path->nodes[0]);
} else
ret = 0;
btrfs_release_path(path);
}
fail:
btrfs_free_path(path);
out_unlock:
mutex_unlock(&dir->log_mutex);
if (ret == -ENOSPC) {
btrfs_set_log_full_commit(trans);
ret = 0;
} else if (ret < 0)
btrfs_abort_transaction(trans, ret);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
btrfs_end_log_trans(root);
return err;
}
/* see comments for btrfs_del_dir_entries_in_log */
int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *inode, u64 dirid)
{
struct btrfs_root *log;
u64 index;
int ret;
Btrfs: fix fsync not persisting dentry deletions due to inode evictions In order to avoid searches on a log tree when unlinking an inode, we check if the inode being unlinked was logged in the current transaction, as well as the inode of its parent directory. When any of the inodes are logged, we proceed to delete directory items and inode reference items from the log, to ensure that if a subsequent fsync of only the inode being unlinked or only of the parent directory when the other is not fsync'ed as well, does not result in the entry still existing after a power failure. That check however is not reliable when one of the inodes involved (the one being unlinked or its parent directory's inode) is evicted, since the logged_trans field is transient, that is, it is not stored on disk, so it is lost when the inode is evicted and loaded into memory again (which is set to zero on load). As a consequence the checks currently being done by btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always return true if the inode was evicted before, regardless of the inode having been logged or not before (and in the current transaction), this results in the dentry being unlinked still existing after a log replay if after the unlink operation only one of the inodes involved is fsync'ed. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ xfs_io -c fsync /mnt/dir/foo # Keep an open file descriptor on our directory while we evict inodes. # We just want to evict the file's inode, the directory's inode must not # be evicted. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time to background process to chdir to our test # directory. $ sleep 0.5 # Trigger eviction of the file's inode. $ echo 2 > /proc/sys/vm/drop_caches # Unlink our file and fsync the parent directory. After a power failure # we don't expect to see the file anymore, since we fsync'ed the parent # directory. $ rm -f $SCRATCH_MNT/dir/foo $ xfs_io -c fsync /mnt/dir <power failure> $ mount /dev/sdb /mnt $ ls /mnt/dir foo $ --> file still there, unlink not persisted despite explicit fsync on dir Fix this by checking if the inode has the full_sync bit set in its runtime flags as well, since that bit is set everytime an inode is loaded from disk, or for other less common cases such as after a shrinking truncate or failure to allocate extent maps for holes, and gets cleared after the first fsync. Also consider the inode as possibly logged only if it was last modified in the current transaction (besides having the full_fsync flag set). Fixes: 3a5f1d458ad161 ("Btrfs: Optimize btree walking while logging inodes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-19 12:05:39 +00:00
if (!inode_logged(trans, inode))
return 0;
ret = join_running_log_trans(root);
if (ret)
return 0;
log = root->log_root;
mutex_lock(&inode->log_mutex);
ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
dirid, &index);
mutex_unlock(&inode->log_mutex);
if (ret == -ENOSPC) {
btrfs_set_log_full_commit(trans);
ret = 0;
} else if (ret < 0 && ret != -ENOENT)
btrfs_abort_transaction(trans, ret);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
btrfs_end_log_trans(root);
return ret;
}
/*
* creates a range item in the log for 'dirid'. first_offset and
* last_offset tell us which parts of the key space the log should
* be considered authoritative for.
*/
static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
int key_type, u64 dirid,
u64 first_offset, u64 last_offset)
{
int ret;
struct btrfs_key key;
struct btrfs_dir_log_item *item;
key.objectid = dirid;
key.offset = first_offset;
if (key_type == BTRFS_DIR_ITEM_KEY)
key.type = BTRFS_DIR_LOG_ITEM_KEY;
else
key.type = BTRFS_DIR_LOG_INDEX_KEY;
ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
if (ret)
return ret;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
/*
* log all the items included in the current transaction for a given
* directory. This also creates the range items in the log tree required
* to replay anything deleted before the fsync
*/
static noinline int log_dir_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path, int key_type,
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
struct btrfs_log_ctx *ctx,
u64 min_offset, u64 *last_offset_ret)
{
struct btrfs_key min_key;
struct btrfs_root *log = root->log_root;
struct extent_buffer *src;
int err = 0;
int ret;
int i;
int nritems;
u64 first_offset = min_offset;
u64 last_offset = (u64)-1;
u64 ino = btrfs_ino(inode);
log = root->log_root;
min_key.objectid = ino;
min_key.type = key_type;
min_key.offset = min_offset;
ret = btrfs_search_forward(root, &min_key, path, trans->transid);
/*
* we didn't find anything from this transaction, see if there
* is anything at all
*/
if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
min_key.objectid = ino;
min_key.type = key_type;
min_key.offset = (u64)-1;
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret < 0) {
btrfs_release_path(path);
return ret;
}
ret = btrfs_previous_item(root, path, ino, key_type);
/* if ret == 0 there are items for this type,
* create a range to tell us the last key of this type.
* otherwise, there are no items in this directory after
* *min_offset, and we create a range to indicate that.
*/
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp,
path->slots[0]);
if (key_type == tmp.type)
first_offset = max(min_offset, tmp.offset) + 1;
}
goto done;
}
/* go backward to find any previous key */
ret = btrfs_previous_item(root, path, ino, key_type);
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
if (key_type == tmp.type) {
first_offset = tmp.offset;
ret = overwrite_item(trans, log, dst_path,
path->nodes[0], path->slots[0],
&tmp);
if (ret) {
err = ret;
goto done;
}
}
}
btrfs_release_path(path);
/*
* Find the first key from this transaction again. See the note for
* log_new_dir_dentries, if we're logging a directory recursively we
* won't be holding its i_mutex, which means we can modify the directory
* while we're logging it. If we remove an entry between our first
* search and this search we'll not find the key again and can just
* bail.
*/
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret != 0)
goto done;
/*
* we have a block from this transaction, log every item in it
* from our directory
*/
while (1) {
struct btrfs_key tmp;
src = path->nodes[0];
nritems = btrfs_header_nritems(src);
for (i = path->slots[0]; i < nritems; i++) {
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
struct btrfs_dir_item *di;
btrfs_item_key_to_cpu(src, &min_key, i);
if (min_key.objectid != ino || min_key.type != key_type)
goto done;
ret = overwrite_item(trans, log, dst_path, src, i,
&min_key);
if (ret) {
err = ret;
goto done;
}
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
/*
* We must make sure that when we log a directory entry,
* the corresponding inode, after log replay, has a
* matching link count. For example:
*
* touch foo
* mkdir mydir
* sync
* ln foo mydir/bar
* xfs_io -c "fsync" mydir
* <crash>
* <mount fs and log replay>
*
* Would result in a fsync log that when replayed, our
* file inode would have a link count of 1, but we get
* two directory entries pointing to the same inode.
* After removing one of the names, it would not be
* possible to remove the other name, which resulted
* always in stale file handle errors, and would not
* be possible to rmdir the parent directory, since
* its i_size could never decrement to the value
* BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors.
*/
di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
btrfs_dir_item_key_to_cpu(src, di, &tmp);
if (ctx &&
(btrfs_dir_transid(src, di) == trans->transid ||
btrfs_dir_type(src, di) == BTRFS_FT_DIR) &&
tmp.type != BTRFS_ROOT_ITEM_KEY)
ctx->log_new_dentries = true;
}
path->slots[0] = nritems;
/*
* look ahead to the next item and see if it is also
* from this directory and from this transaction
*/
ret = btrfs_next_leaf(root, path);
if (ret) {
if (ret == 1)
last_offset = (u64)-1;
else
err = ret;
goto done;
}
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
if (tmp.objectid != ino || tmp.type != key_type) {
last_offset = (u64)-1;
goto done;
}
if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
ret = overwrite_item(trans, log, dst_path,
path->nodes[0], path->slots[0],
&tmp);
if (ret)
err = ret;
else
last_offset = tmp.offset;
goto done;
}
}
done:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (err == 0) {
*last_offset_ret = last_offset;
/*
* insert the log range keys to indicate where the log
* is valid
*/
ret = insert_dir_log_key(trans, log, path, key_type,
ino, first_offset, last_offset);
if (ret)
err = ret;
}
return err;
}
/*
* logging directories is very similar to logging inodes, We find all the items
* from the current transaction and write them to the log.
*
* The recovery code scans the directory in the subvolume, and if it finds a
* key in the range logged that is not present in the log tree, then it means
* that dir entry was unlinked during the transaction.
*
* In order for that scan to work, we must include one key smaller than
* the smallest logged by this transaction and one key larger than the largest
* key logged by this transaction.
*/
static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
struct btrfs_path *path,
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx)
{
u64 min_key;
u64 max_key;
int ret;
int key_type = BTRFS_DIR_ITEM_KEY;
again:
min_key = 0;
max_key = 0;
while (1) {
ret = log_dir_items(trans, root, inode, path, dst_path, key_type,
ctx, min_key, &max_key);
if (ret)
return ret;
if (max_key == (u64)-1)
break;
min_key = max_key + 1;
}
if (key_type == BTRFS_DIR_ITEM_KEY) {
key_type = BTRFS_DIR_INDEX_KEY;
goto again;
}
return 0;
}
/*
* a helper function to drop items from the log before we relog an
* inode. max_key_type indicates the highest item type to remove.
* This cannot be run for file data extents because it does not
* free the extents they point to.
*/
static int drop_objectid_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 objectid, int max_key_type)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
int start_slot;
key.objectid = objectid;
key.type = max_key_type;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
BUG_ON(ret == 0); /* Logic error */
if (ret < 0)
break;
if (path->slots[0] == 0)
break;
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != objectid)
break;
found_key.offset = 0;
found_key.type = 0;
ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
&start_slot);
if (ret < 0)
break;
ret = btrfs_del_items(trans, log, path, start_slot,
path->slots[0] - start_slot + 1);
/*
* If start slot isn't 0 then we don't need to re-search, we've
* found the last guy with the objectid in this tree.
*/
if (ret || start_slot != 0)
break;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret > 0)
ret = 0;
return ret;
}
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
struct inode *inode, int log_inode_only,
u64 logged_isize)
{
struct btrfs_map_token token;
btrfs_init_map_token(&token, leaf);
if (log_inode_only) {
/* set the generation to zero so the recover code
* can tell the difference between an logging
* just to say 'this inode exists' and a logging
* to say 'update this inode with these values'
*/
btrfs_set_token_inode_generation(leaf, item, 0, &token);
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
btrfs_set_token_inode_size(leaf, item, logged_isize, &token);
} else {
btrfs_set_token_inode_generation(leaf, item,
BTRFS_I(inode)->generation,
&token);
btrfs_set_token_inode_size(leaf, item, inode->i_size, &token);
}
btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
btrfs_set_token_timespec_sec(leaf, &item->atime,
inode->i_atime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->atime,
inode->i_atime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->mtime,
inode->i_mtime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->mtime,
inode->i_mtime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->ctime,
inode->i_ctime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->ctime,
inode->i_ctime.tv_nsec, &token);
btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
&token);
btrfs_set_token_inode_sequence(leaf, item,
inode_peek_iversion(inode), &token);
btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
btrfs_set_token_inode_block_group(leaf, item, 0, &token);
}
static int log_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct btrfs_path *path,
struct btrfs_inode *inode)
{
struct btrfs_inode_item *inode_item;
int ret;
ret = btrfs_insert_empty_item(trans, log, path,
&inode->location, sizeof(*inode_item));
if (ret && ret != -EEXIST)
return ret;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
0, 0);
btrfs_release_path(path);
return 0;
}
static noinline int copy_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *dst_path,
struct btrfs_path *src_path, u64 *last_extent,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
int start_slot, int nr, int inode_only,
u64 logged_isize)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
unsigned long src_offset;
unsigned long dst_offset;
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item *extent;
struct btrfs_inode_item *inode_item;
struct extent_buffer *src = src_path->nodes[0];
struct btrfs_key first_key, last_key, key;
int ret;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
char *ins_data;
int i;
Btrfs: move data checksumming into a dedicated tree Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 21:58:54 +00:00
struct list_head ordered_sums;
int skip_csum = inode->flags & BTRFS_INODE_NODATASUM;
bool has_extents = false;
Btrfs: fix hole detection during file fsync The file hole detection logic during a file fsync wasn't correct, because it didn't look back (in a previous leaf) for the last file extent item that can be in a leaf to the left of our leaf and that has a generation lower than the current transaction id. This made it assume that a hole exists when it really doesn't exist in the file. Such false positive hole detection happens in the following scenario: * We have a file that has many file extent items, covering 3 or more btree leafs (the first leaf must contain non file extent items too). * Two ranges of the file are modified, with their extent items being located at 2 different leafs and those leafs aren't consecutive. * When processing the second modified leaf, we weren't checking if some file extent item exists that is located in some leaf that is between our 2 modified leafs, and therefore assumed the range defined between the last file extent item in the first leaf and the first file extent item in the second leaf matched a hole. Fortunately this didn't result in overriding the log with wrong data, instead it made the last loop in copy_items() attempt to insert a duplicated key (for a hole file extent item), which makes the file fsync code return with -EEXIST to file.c:btrfs_sync_file() which in turn ends up doing a full transaction commit, which is much more expensive then writing only to the log tree and wait for it to be durably persisted (as well as the file's modified extents/pages). Therefore fix the hole detection logic, so that we don't pay the cost of doing full transaction commits. I could trigger this issue with the following test for xfstests (which never fails, either without or with this patch). The last fsync call results in a full transaction commit, due to the -EEXIST error mentioned above. I could also observe this behaviour happening frequently when running xfstests/generic/075 in a loop. Test: _cleanup() { _cleanup_flakey rm -fr $tmp } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _need_to_be_root rm -f $seqres.full # Create a file with many file extent items, each representing a 4Kb extent. # These items span 3 btree leaves, of 16Kb each (default mkfs.btrfs leaf size # as of btrfs-progs 3.12). _scratch_mkfs -l 16384 >/dev/null 2>&1 _init_flakey SAVE_MOUNT_OPTIONS="$MOUNT_OPTIONS" MOUNT_OPTIONS="$MOUNT_OPTIONS -o commit=999" _mount_flakey # First fsync, inode has BTRFS_INODE_NEEDS_FULL_SYNC flag set. $XFS_IO_PROG -f -c "pwrite -S 0x01 -b 4096 0 4096" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # For any of the following fsync calls, inode doesn't have the flag # BTRFS_INODE_NEEDS_FULL_SYNC set. for ((i = 1; i <= 500; i++)); do OFFSET=$((4096 * i)) LEN=4096 $XFS_IO_PROG -c "pwrite -S 0x01 $OFFSET $LEN" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io done # Commit transaction and bump next transaction's id (to 7). sync # Truncate will set the BTRFS_INODE_NEEDS_FULL_SYNC flag in the btrfs's # inode runtime flags. $XFS_IO_PROG -c "truncate 2048000" $SCRATCH_MNT/foo # Commit transaction and bump next transaction's id (to 8). sync # Touch 1 extent item from the first leaf and 1 from the last leaf. The leaf # in the middle, containing only file extent items, isn't touched. So the # next fsync, when calling btrfs_search_forward(), won't visit that middle # leaf. First and 3rd leaf have now a generation with value 8, while the # middle leaf remains with a generation with value 6. $XFS_IO_PROG \ -c "pwrite -S 0xee -b 4096 0 4096" \ -c "pwrite -S 0xff -b 4096 2043904 4096" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io _load_flakey_table $FLAKEY_DROP_WRITES md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES # During mount, we'll replay the log created by the fsync above, and the file's # md5 digest should be the same we got before the unmount. _mount_flakey md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey MOUNT_OPTIONS="$SAVE_MOUNT_OPTIONS" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-07 11:00:44 +00:00
bool need_find_last_extent = true;
bool done = false;
Btrfs: move data checksumming into a dedicated tree Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 21:58:54 +00:00
INIT_LIST_HEAD(&ordered_sums);
ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
nr * sizeof(u32), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
first_key.objectid = (u64)-1;
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
for (i = 0; i < nr; i++) {
ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
}
ret = btrfs_insert_empty_items(trans, log, dst_path,
ins_keys, ins_sizes, nr);
if (ret) {
kfree(ins_data);
return ret;
}
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
for (i = 0; i < nr; i++, dst_path->slots[0]++) {
dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
dst_path->slots[0]);
src_offset = btrfs_item_ptr_offset(src, start_slot + i);
if (i == nr - 1)
last_key = ins_keys[i];
if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
inode_item = btrfs_item_ptr(dst_path->nodes[0],
dst_path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, dst_path->nodes[0], inode_item,
&inode->vfs_inode,
inode_only == LOG_INODE_EXISTS,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
logged_isize);
} else {
copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
src_offset, ins_sizes[i]);
}
/*
* We set need_find_last_extent here in case we know we were
* processing other items and then walk into the first extent in
* the inode. If we don't hit an extent then nothing changes,
* we'll do the last search the next time around.
*/
if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY) {
has_extents = true;
Btrfs: fix hole detection during file fsync The file hole detection logic during a file fsync wasn't correct, because it didn't look back (in a previous leaf) for the last file extent item that can be in a leaf to the left of our leaf and that has a generation lower than the current transaction id. This made it assume that a hole exists when it really doesn't exist in the file. Such false positive hole detection happens in the following scenario: * We have a file that has many file extent items, covering 3 or more btree leafs (the first leaf must contain non file extent items too). * Two ranges of the file are modified, with their extent items being located at 2 different leafs and those leafs aren't consecutive. * When processing the second modified leaf, we weren't checking if some file extent item exists that is located in some leaf that is between our 2 modified leafs, and therefore assumed the range defined between the last file extent item in the first leaf and the first file extent item in the second leaf matched a hole. Fortunately this didn't result in overriding the log with wrong data, instead it made the last loop in copy_items() attempt to insert a duplicated key (for a hole file extent item), which makes the file fsync code return with -EEXIST to file.c:btrfs_sync_file() which in turn ends up doing a full transaction commit, which is much more expensive then writing only to the log tree and wait for it to be durably persisted (as well as the file's modified extents/pages). Therefore fix the hole detection logic, so that we don't pay the cost of doing full transaction commits. I could trigger this issue with the following test for xfstests (which never fails, either without or with this patch). The last fsync call results in a full transaction commit, due to the -EEXIST error mentioned above. I could also observe this behaviour happening frequently when running xfstests/generic/075 in a loop. Test: _cleanup() { _cleanup_flakey rm -fr $tmp } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _need_to_be_root rm -f $seqres.full # Create a file with many file extent items, each representing a 4Kb extent. # These items span 3 btree leaves, of 16Kb each (default mkfs.btrfs leaf size # as of btrfs-progs 3.12). _scratch_mkfs -l 16384 >/dev/null 2>&1 _init_flakey SAVE_MOUNT_OPTIONS="$MOUNT_OPTIONS" MOUNT_OPTIONS="$MOUNT_OPTIONS -o commit=999" _mount_flakey # First fsync, inode has BTRFS_INODE_NEEDS_FULL_SYNC flag set. $XFS_IO_PROG -f -c "pwrite -S 0x01 -b 4096 0 4096" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # For any of the following fsync calls, inode doesn't have the flag # BTRFS_INODE_NEEDS_FULL_SYNC set. for ((i = 1; i <= 500; i++)); do OFFSET=$((4096 * i)) LEN=4096 $XFS_IO_PROG -c "pwrite -S 0x01 $OFFSET $LEN" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io done # Commit transaction and bump next transaction's id (to 7). sync # Truncate will set the BTRFS_INODE_NEEDS_FULL_SYNC flag in the btrfs's # inode runtime flags. $XFS_IO_PROG -c "truncate 2048000" $SCRATCH_MNT/foo # Commit transaction and bump next transaction's id (to 8). sync # Touch 1 extent item from the first leaf and 1 from the last leaf. The leaf # in the middle, containing only file extent items, isn't touched. So the # next fsync, when calling btrfs_search_forward(), won't visit that middle # leaf. First and 3rd leaf have now a generation with value 8, while the # middle leaf remains with a generation with value 6. $XFS_IO_PROG \ -c "pwrite -S 0xee -b 4096 0 4096" \ -c "pwrite -S 0xff -b 4096 2043904 4096" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io _load_flakey_table $FLAKEY_DROP_WRITES md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES # During mount, we'll replay the log created by the fsync above, and the file's # md5 digest should be the same we got before the unmount. _mount_flakey md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey MOUNT_OPTIONS="$SAVE_MOUNT_OPTIONS" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-07 11:00:44 +00:00
if (first_key.objectid == (u64)-1)
first_key = ins_keys[i];
} else {
need_find_last_extent = false;
}
/* take a reference on file data extents so that truncates
* or deletes of this inode don't have to relog the inode
* again
*/
if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY &&
!skip_csum) {
int found_type;
extent = btrfs_item_ptr(src, start_slot + i,
struct btrfs_file_extent_item);
Btrfs: do not flush csum items of unchanged file data during treelog The current code relogs the entire inode every time during fsync log, and it is much better suited to small files rather than large ones. During my performance test, the fsync performace of large files sucks, and we can ascribe this to the tremendous amount of csum infos of the large ones, cause we have to flush all of these csum infos into log trees even when there are only _one_ change in the whole file data. Apparently, to optimize fsync, we need to create a filter to skip the unnecessary csum ones, that is, the corresponding file data remains unchanged before this fsync. Here I have some test results to show, I use sysbench to do "random write + fsync". === sysbench --test=fileio --num-threads=1 --file-num=2 --file-block-size=4K --file-total-size=8G --file-test-mode=rndwr --file-io-mode=sync --file-extra-flags= [prepare, run] === Sysbench args: - Number of threads: 1 - Extra file open flags: 0 - 2 files, 4Gb each - Block size 4Kb - Number of random requests for random IO: 10000 - Read/Write ratio for combined random IO test: 1.50 - Periodic FSYNC enabled, calling fsync() each 100 requests. - Calling fsync() at the end of test, Enabled. - Using synchronous I/O mode - Doing random write test Sysbench results: === Operations performed: 0 Read, 10000 Write, 200 Other = 10200 Total Read 0b Written 39.062Mb Total transferred 39.062Mb === a) without patch: (*SPEED* : 451.01Kb/sec) 112.75 Requests/sec executed b) with patch: (*SPEED* : 4.7533Mb/sec) 1216.84 Requests/sec executed PS: I've made a _sub transid_ stuff patch, but it does not perform as effectively as this patch, and I'm wanderring where the problem is and trying to improve it more. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-06 02:36:09 +00:00
if (btrfs_file_extent_generation(src, extent) < trans->transid)
continue;
found_type = btrfs_file_extent_type(src, extent);
if (found_type == BTRFS_FILE_EXTENT_REG) {
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
u64 ds, dl, cs, cl;
ds = btrfs_file_extent_disk_bytenr(src,
extent);
/* ds == 0 is a hole */
if (ds == 0)
continue;
dl = btrfs_file_extent_disk_num_bytes(src,
extent);
cs = btrfs_file_extent_offset(src, extent);
cl = btrfs_file_extent_num_bytes(src,
extent);
if (btrfs_file_extent_compression(src,
extent)) {
cs = 0;
cl = dl;
}
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
ret = btrfs_lookup_csums_range(
fs_info->csum_root,
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
ds + cs, ds + cs + cl - 1,
&ordered_sums, 0);
if (ret) {
btrfs_release_path(dst_path);
kfree(ins_data);
return ret;
}
}
}
}
btrfs_mark_buffer_dirty(dst_path->nodes[0]);
btrfs_release_path(dst_path);
kfree(ins_data);
Btrfs: move data checksumming into a dedicated tree Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 21:58:54 +00:00
/*
* we have to do this after the loop above to avoid changing the
* log tree while trying to change the log tree.
*/
ret = 0;
while (!list_empty(&ordered_sums)) {
Btrfs: move data checksumming into a dedicated tree Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 21:58:54 +00:00
struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = btrfs_csum_file_blocks(trans, log, sums);
Btrfs: move data checksumming into a dedicated tree Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08 21:58:54 +00:00
list_del(&sums->list);
kfree(sums);
}
if (!has_extents)
return ret;
Btrfs: fix hole detection during file fsync The file hole detection logic during a file fsync wasn't correct, because it didn't look back (in a previous leaf) for the last file extent item that can be in a leaf to the left of our leaf and that has a generation lower than the current transaction id. This made it assume that a hole exists when it really doesn't exist in the file. Such false positive hole detection happens in the following scenario: * We have a file that has many file extent items, covering 3 or more btree leafs (the first leaf must contain non file extent items too). * Two ranges of the file are modified, with their extent items being located at 2 different leafs and those leafs aren't consecutive. * When processing the second modified leaf, we weren't checking if some file extent item exists that is located in some leaf that is between our 2 modified leafs, and therefore assumed the range defined between the last file extent item in the first leaf and the first file extent item in the second leaf matched a hole. Fortunately this didn't result in overriding the log with wrong data, instead it made the last loop in copy_items() attempt to insert a duplicated key (for a hole file extent item), which makes the file fsync code return with -EEXIST to file.c:btrfs_sync_file() which in turn ends up doing a full transaction commit, which is much more expensive then writing only to the log tree and wait for it to be durably persisted (as well as the file's modified extents/pages). Therefore fix the hole detection logic, so that we don't pay the cost of doing full transaction commits. I could trigger this issue with the following test for xfstests (which never fails, either without or with this patch). The last fsync call results in a full transaction commit, due to the -EEXIST error mentioned above. I could also observe this behaviour happening frequently when running xfstests/generic/075 in a loop. Test: _cleanup() { _cleanup_flakey rm -fr $tmp } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _need_to_be_root rm -f $seqres.full # Create a file with many file extent items, each representing a 4Kb extent. # These items span 3 btree leaves, of 16Kb each (default mkfs.btrfs leaf size # as of btrfs-progs 3.12). _scratch_mkfs -l 16384 >/dev/null 2>&1 _init_flakey SAVE_MOUNT_OPTIONS="$MOUNT_OPTIONS" MOUNT_OPTIONS="$MOUNT_OPTIONS -o commit=999" _mount_flakey # First fsync, inode has BTRFS_INODE_NEEDS_FULL_SYNC flag set. $XFS_IO_PROG -f -c "pwrite -S 0x01 -b 4096 0 4096" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # For any of the following fsync calls, inode doesn't have the flag # BTRFS_INODE_NEEDS_FULL_SYNC set. for ((i = 1; i <= 500; i++)); do OFFSET=$((4096 * i)) LEN=4096 $XFS_IO_PROG -c "pwrite -S 0x01 $OFFSET $LEN" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io done # Commit transaction and bump next transaction's id (to 7). sync # Truncate will set the BTRFS_INODE_NEEDS_FULL_SYNC flag in the btrfs's # inode runtime flags. $XFS_IO_PROG -c "truncate 2048000" $SCRATCH_MNT/foo # Commit transaction and bump next transaction's id (to 8). sync # Touch 1 extent item from the first leaf and 1 from the last leaf. The leaf # in the middle, containing only file extent items, isn't touched. So the # next fsync, when calling btrfs_search_forward(), won't visit that middle # leaf. First and 3rd leaf have now a generation with value 8, while the # middle leaf remains with a generation with value 6. $XFS_IO_PROG \ -c "pwrite -S 0xee -b 4096 0 4096" \ -c "pwrite -S 0xff -b 4096 2043904 4096" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io _load_flakey_table $FLAKEY_DROP_WRITES md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES # During mount, we'll replay the log created by the fsync above, and the file's # md5 digest should be the same we got before the unmount. _mount_flakey md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey MOUNT_OPTIONS="$SAVE_MOUNT_OPTIONS" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-07 11:00:44 +00:00
if (need_find_last_extent && *last_extent == first_key.offset) {
/*
* We don't have any leafs between our current one and the one
* we processed before that can have file extent items for our
* inode (and have a generation number smaller than our current
* transaction id).
*/
need_find_last_extent = false;
}
/*
* Because we use btrfs_search_forward we could skip leaves that were
* not modified and then assume *last_extent is valid when it really
* isn't. So back up to the previous leaf and read the end of the last
* extent before we go and fill in holes.
*/
if (need_find_last_extent) {
u64 len;
ret = btrfs_prev_leaf(inode->root, src_path);
if (ret < 0)
return ret;
if (ret)
goto fill_holes;
if (src_path->slots[0])
src_path->slots[0]--;
src = src_path->nodes[0];
btrfs_item_key_to_cpu(src, &key, src_path->slots[0]);
if (key.objectid != btrfs_ino(inode) ||
key.type != BTRFS_EXTENT_DATA_KEY)
goto fill_holes;
extent = btrfs_item_ptr(src, src_path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(src, extent) ==
BTRFS_FILE_EXTENT_INLINE) {
len = btrfs_file_extent_ram_bytes(src, extent);
*last_extent = ALIGN(key.offset + len,
fs_info->sectorsize);
} else {
len = btrfs_file_extent_num_bytes(src, extent);
*last_extent = key.offset + len;
}
}
fill_holes:
/* So we did prev_leaf, now we need to move to the next leaf, but a few
* things could have happened
*
* 1) A merge could have happened, so we could currently be on a leaf
* that holds what we were copying in the first place.
* 2) A split could have happened, and now not all of the items we want
* are on the same leaf.
*
* So we need to adjust how we search for holes, we need to drop the
* path and re-search for the first extent key we found, and then walk
* forward until we hit the last one we copied.
*/
if (need_find_last_extent) {
/* btrfs_prev_leaf could return 1 without releasing the path */
btrfs_release_path(src_path);
ret = btrfs_search_slot(NULL, inode->root, &first_key,
src_path, 0, 0);
if (ret < 0)
return ret;
ASSERT(ret == 0);
src = src_path->nodes[0];
i = src_path->slots[0];
} else {
i = start_slot;
}
/*
* Ok so here we need to go through and fill in any holes we may have
* to make sure that holes are punched for those areas in case they had
* extents previously.
*/
while (!done) {
u64 offset, len;
u64 extent_end;
if (i >= btrfs_header_nritems(src_path->nodes[0])) {
ret = btrfs_next_leaf(inode->root, src_path);
if (ret < 0)
return ret;
ASSERT(ret == 0);
src = src_path->nodes[0];
i = 0;
need_find_last_extent = true;
}
btrfs_item_key_to_cpu(src, &key, i);
if (!btrfs_comp_cpu_keys(&key, &last_key))
done = true;
if (key.objectid != btrfs_ino(inode) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
i++;
continue;
}
extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(src, extent) ==
BTRFS_FILE_EXTENT_INLINE) {
len = btrfs_file_extent_ram_bytes(src, extent);
extent_end = ALIGN(key.offset + len,
fs_info->sectorsize);
} else {
len = btrfs_file_extent_num_bytes(src, extent);
extent_end = key.offset + len;
}
i++;
if (*last_extent == key.offset) {
*last_extent = extent_end;
continue;
}
offset = *last_extent;
len = key.offset - *last_extent;
ret = btrfs_insert_file_extent(trans, log, btrfs_ino(inode),
offset, 0, 0, len, 0, len, 0, 0, 0);
if (ret)
break;
Btrfs: fix hole detection during file fsync The file hole detection logic during a file fsync wasn't correct, because it didn't look back (in a previous leaf) for the last file extent item that can be in a leaf to the left of our leaf and that has a generation lower than the current transaction id. This made it assume that a hole exists when it really doesn't exist in the file. Such false positive hole detection happens in the following scenario: * We have a file that has many file extent items, covering 3 or more btree leafs (the first leaf must contain non file extent items too). * Two ranges of the file are modified, with their extent items being located at 2 different leafs and those leafs aren't consecutive. * When processing the second modified leaf, we weren't checking if some file extent item exists that is located in some leaf that is between our 2 modified leafs, and therefore assumed the range defined between the last file extent item in the first leaf and the first file extent item in the second leaf matched a hole. Fortunately this didn't result in overriding the log with wrong data, instead it made the last loop in copy_items() attempt to insert a duplicated key (for a hole file extent item), which makes the file fsync code return with -EEXIST to file.c:btrfs_sync_file() which in turn ends up doing a full transaction commit, which is much more expensive then writing only to the log tree and wait for it to be durably persisted (as well as the file's modified extents/pages). Therefore fix the hole detection logic, so that we don't pay the cost of doing full transaction commits. I could trigger this issue with the following test for xfstests (which never fails, either without or with this patch). The last fsync call results in a full transaction commit, due to the -EEXIST error mentioned above. I could also observe this behaviour happening frequently when running xfstests/generic/075 in a loop. Test: _cleanup() { _cleanup_flakey rm -fr $tmp } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _need_to_be_root rm -f $seqres.full # Create a file with many file extent items, each representing a 4Kb extent. # These items span 3 btree leaves, of 16Kb each (default mkfs.btrfs leaf size # as of btrfs-progs 3.12). _scratch_mkfs -l 16384 >/dev/null 2>&1 _init_flakey SAVE_MOUNT_OPTIONS="$MOUNT_OPTIONS" MOUNT_OPTIONS="$MOUNT_OPTIONS -o commit=999" _mount_flakey # First fsync, inode has BTRFS_INODE_NEEDS_FULL_SYNC flag set. $XFS_IO_PROG -f -c "pwrite -S 0x01 -b 4096 0 4096" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # For any of the following fsync calls, inode doesn't have the flag # BTRFS_INODE_NEEDS_FULL_SYNC set. for ((i = 1; i <= 500; i++)); do OFFSET=$((4096 * i)) LEN=4096 $XFS_IO_PROG -c "pwrite -S 0x01 $OFFSET $LEN" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io done # Commit transaction and bump next transaction's id (to 7). sync # Truncate will set the BTRFS_INODE_NEEDS_FULL_SYNC flag in the btrfs's # inode runtime flags. $XFS_IO_PROG -c "truncate 2048000" $SCRATCH_MNT/foo # Commit transaction and bump next transaction's id (to 8). sync # Touch 1 extent item from the first leaf and 1 from the last leaf. The leaf # in the middle, containing only file extent items, isn't touched. So the # next fsync, when calling btrfs_search_forward(), won't visit that middle # leaf. First and 3rd leaf have now a generation with value 8, while the # middle leaf remains with a generation with value 6. $XFS_IO_PROG \ -c "pwrite -S 0xee -b 4096 0 4096" \ -c "pwrite -S 0xff -b 4096 2043904 4096" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io _load_flakey_table $FLAKEY_DROP_WRITES md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES # During mount, we'll replay the log created by the fsync above, and the file's # md5 digest should be the same we got before the unmount. _mount_flakey md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey MOUNT_OPTIONS="$SAVE_MOUNT_OPTIONS" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-07 11:00:44 +00:00
*last_extent = extent_end;
}
Btrfs: fix fsync after hole punching when using no-holes feature When we have the no-holes mode enabled and fsync a file after punching a hole in it, we can end up not logging the whole hole range in the log tree. This happens if the file has extent items that span more than one leaf and we punch a hole that covers a range that starts in a leaf but does not go beyond the offset of the first extent in the next leaf. Example: $ mkfs.btrfs -f -O no-holes -n 65536 /dev/sdb $ mount /dev/sdb /mnt $ for ((i = 0; i <= 831; i++)); do offset=$((i * 2 * 256 * 1024)) xfs_io -f -c "pwrite -S 0xab -b 256K $offset 256K" \ /mnt/foobar >/dev/null done $ sync # We now have 2 leafs in our filesystem fs tree, the first leaf has an # item corresponding the extent at file offset 216530944 and the second # leaf has a first item corresponding to the extent at offset 217055232. # Now we punch a hole that partially covers the range of the extent at # offset 216530944 but does go beyond the offset 217055232. $ xfs_io -c "fpunch $((216530944 + 128 * 1024 - 4000)) 256K" /mnt/foobar $ xfs_io -c "fsync" /mnt/foobar <power fail> # mount to replay the log $ mount /dev/sdb /mnt # Before this patch, only the subrange [216658016, 216662016[ (length of # 4000 bytes) was logged, leaving an incorrect file layout after log # replay. Fix this by checking if there is a hole between the last extent item that we processed and the first extent item in the next leaf, and if there is one, log an explicit hole extent item. Fixes: 16e7549f045d ("Btrfs: incompatible format change to remove hole extents") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 22:59:00 +00:00
/*
* Check if there is a hole between the last extent found in our leaf
* and the first extent in the next leaf. If there is one, we need to
* log an explicit hole so that at replay time we can punch the hole.
*/
if (ret == 0 &&
key.objectid == btrfs_ino(inode) &&
key.type == BTRFS_EXTENT_DATA_KEY &&
i == btrfs_header_nritems(src_path->nodes[0])) {
ret = btrfs_next_leaf(inode->root, src_path);
need_find_last_extent = true;
if (ret > 0) {
ret = 0;
} else if (ret == 0) {
btrfs_item_key_to_cpu(src_path->nodes[0], &key,
src_path->slots[0]);
if (key.objectid == btrfs_ino(inode) &&
key.type == BTRFS_EXTENT_DATA_KEY &&
*last_extent < key.offset) {
const u64 len = key.offset - *last_extent;
ret = btrfs_insert_file_extent(trans, log,
btrfs_ino(inode),
*last_extent, 0,
0, len, 0, len,
0, 0, 0);
Btrfs: avoid fallback to transaction commit during fsync of files with holes When we are doing a full fsync (bit BTRFS_INODE_NEEDS_FULL_SYNC set) of a file that has holes and has file extent items spanning two or more leafs, we can end up falling to back to a full transaction commit due to a logic bug that leads to failure to insert a duplicate file extent item that is meant to represent a hole between the last file extent item of a leaf and the first file extent item in the next leaf. The failure (EEXIST error) leads to a transaction commit (as most errors when logging an inode do). For example, we have the two following leafs: Leaf N: ----------------------------------------------- | ..., ..., ..., (257, FILE_EXTENT_ITEM, 64K) | ----------------------------------------------- The file extent item at the end of leaf N has a length of 4Kb, representing the file range from 64K to 68K - 1. Leaf N + 1: ----------------------------------------------- | (257, FILE_EXTENT_ITEM, 72K), ..., ..., ... | ----------------------------------------------- The file extent item at the first slot of leaf N + 1 has a length of 4Kb too, representing the file range from 72K to 76K - 1. During the full fsync path, when we are at tree-log.c:copy_items() with leaf N as a parameter, after processing the last file extent item, that represents the extent at offset 64K, we take a look at the first file extent item at the next leaf (leaf N + 1), and notice there's a 4K hole between the two extents, and therefore we insert a file extent item representing that hole, starting at file offset 68K and ending at offset 72K - 1. However we don't update the value of *last_extent, which is used to represent the end offset (plus 1, non-inclusive end) of the last file extent item inserted in the log, so it stays with a value of 68K and not with a value of 72K. Then, when copy_items() is called for leaf N + 1, because the value of *last_extent is smaller then the offset of the first extent item in the leaf (68K < 72K), we look at the last file extent item in the previous leaf (leaf N) and see it there's a 4K gap between it and our first file extent item (again, 68K < 72K), so we decide to insert a file extent item representing the hole, starting at file offset 68K and ending at offset 72K - 1, this insertion will fail with -EEXIST being returned from btrfs_insert_file_extent() because we already inserted a file extent item representing a hole for this offset (68K) in the previous call to copy_items(), when processing leaf N. The -EEXIST error gets propagated to the fsync callback, btrfs_sync_file(), which falls back to a full transaction commit. Fix this by adjusting *last_extent after inserting a hole when we had to look at the next leaf. Fixes: 4ee3fad34a9c ("Btrfs: fix fsync after hole punching when using no-holes feature") Cc: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-05-06 15:43:51 +00:00
*last_extent += len;
Btrfs: fix fsync after hole punching when using no-holes feature When we have the no-holes mode enabled and fsync a file after punching a hole in it, we can end up not logging the whole hole range in the log tree. This happens if the file has extent items that span more than one leaf and we punch a hole that covers a range that starts in a leaf but does not go beyond the offset of the first extent in the next leaf. Example: $ mkfs.btrfs -f -O no-holes -n 65536 /dev/sdb $ mount /dev/sdb /mnt $ for ((i = 0; i <= 831; i++)); do offset=$((i * 2 * 256 * 1024)) xfs_io -f -c "pwrite -S 0xab -b 256K $offset 256K" \ /mnt/foobar >/dev/null done $ sync # We now have 2 leafs in our filesystem fs tree, the first leaf has an # item corresponding the extent at file offset 216530944 and the second # leaf has a first item corresponding to the extent at offset 217055232. # Now we punch a hole that partially covers the range of the extent at # offset 216530944 but does go beyond the offset 217055232. $ xfs_io -c "fpunch $((216530944 + 128 * 1024 - 4000)) 256K" /mnt/foobar $ xfs_io -c "fsync" /mnt/foobar <power fail> # mount to replay the log $ mount /dev/sdb /mnt # Before this patch, only the subrange [216658016, 216662016[ (length of # 4000 bytes) was logged, leaving an incorrect file layout after log # replay. Fix this by checking if there is a hole between the last extent item that we processed and the first extent item in the next leaf, and if there is one, log an explicit hole extent item. Fixes: 16e7549f045d ("Btrfs: incompatible format change to remove hole extents") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 22:59:00 +00:00
}
}
}
/*
* Need to let the callers know we dropped the path so they should
* re-search.
*/
if (!ret && need_find_last_extent)
ret = 1;
return ret;
}
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
{
struct extent_map *em1, *em2;
em1 = list_entry(a, struct extent_map, list);
em2 = list_entry(b, struct extent_map, list);
if (em1->start < em2->start)
return -1;
else if (em1->start > em2->start)
return 1;
return 0;
}
static int log_extent_csums(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_root *log_root,
const struct extent_map *em)
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
{
u64 csum_offset;
u64 csum_len;
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
LIST_HEAD(ordered_sums);
int ret = 0;
if (inode->flags & BTRFS_INODE_NODATASUM ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
em->block_start == EXTENT_MAP_HOLE)
return 0;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
/* If we're compressed we have to save the entire range of csums. */
if (em->compress_type) {
csum_offset = 0;
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
csum_len = max(em->block_len, em->orig_block_len);
} else {
csum_offset = em->mod_start - em->start;
csum_len = em->mod_len;
}
/* block start is already adjusted for the file extent offset. */
ret = btrfs_lookup_csums_range(trans->fs_info->csum_root,
em->block_start + csum_offset,
em->block_start + csum_offset +
csum_len - 1, &ordered_sums, 0);
if (ret)
return ret;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = btrfs_csum_file_blocks(trans, log_root, sums);
list_del(&sums->list);
kfree(sums);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
}
return ret;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
}
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
static int log_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, struct btrfs_root *root,
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
const struct extent_map *em,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *log = root->log_root;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
struct btrfs_map_token token;
struct btrfs_key key;
u64 extent_offset = em->start - em->orig_start;
u64 block_len;
int ret;
int extent_inserted = 0;
ret = log_extent_csums(trans, inode, log, em);
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
if (ret)
return ret;
ret = __btrfs_drop_extents(trans, log, &inode->vfs_inode, path, em->start,
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
em->start + em->len, NULL, 0, 1,
sizeof(*fi), &extent_inserted);
if (ret)
return ret;
if (!extent_inserted) {
key.objectid = btrfs_ino(inode);
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = em->start;
ret = btrfs_insert_empty_item(trans, log, path, &key,
sizeof(*fi));
if (ret)
return ret;
}
leaf = path->nodes[0];
btrfs_init_map_token(&token, leaf);
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_token_file_extent_generation(leaf, fi, trans->transid,
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
&token);
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
btrfs_set_token_file_extent_type(leaf, fi,
BTRFS_FILE_EXTENT_PREALLOC,
&token);
else
btrfs_set_token_file_extent_type(leaf, fi,
BTRFS_FILE_EXTENT_REG,
&token);
block_len = max(em->block_len, em->orig_block_len);
if (em->compress_type != BTRFS_COMPRESS_NONE) {
btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
em->block_start,
&token);
btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
&token);
} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
em->block_start -
extent_offset, &token);
btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
&token);
} else {
btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token);
btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0,
&token);
}
btrfs_set_token_file_extent_offset(leaf, fi, extent_offset, &token);
btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token);
btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token);
btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type,
&token);
btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token);
btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
return ret;
}
Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-09 15:01:46 +00:00
/*
* Log all prealloc extents beyond the inode's i_size to make sure we do not
* lose them after doing a fast fsync and replaying the log. We scan the
* subvolume's root instead of iterating the inode's extent map tree because
* otherwise we can log incorrect extent items based on extent map conversion.
* That can happen due to the fact that extent maps are merged when they
* are not in the extent map tree's list of modified extents.
*/
static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path)
{
struct btrfs_root *root = inode->root;
struct btrfs_key key;
const u64 i_size = i_size_read(&inode->vfs_inode);
const u64 ino = btrfs_ino(inode);
struct btrfs_path *dst_path = NULL;
u64 last_extent = (u64)-1;
int ins_nr = 0;
int start_slot;
int ret;
if (!(inode->flags & BTRFS_INODE_PREALLOC))
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = i_size;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
&last_extent, start_slot,
ins_nr, 1, 0);
if (ret < 0)
goto out;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid > ino)
break;
if (WARN_ON_ONCE(key.objectid < ino) ||
key.type < BTRFS_EXTENT_DATA_KEY ||
key.offset < i_size) {
path->slots[0]++;
continue;
}
if (last_extent == (u64)-1) {
last_extent = key.offset;
/*
* Avoid logging extent items logged in past fsync calls
* and leading to duplicate keys in the log tree.
*/
do {
ret = btrfs_truncate_inode_items(trans,
root->log_root,
&inode->vfs_inode,
i_size,
BTRFS_EXTENT_DATA_KEY);
} while (ret == -EAGAIN);
if (ret)
goto out;
}
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
if (!dst_path) {
dst_path = btrfs_alloc_path();
if (!dst_path) {
ret = -ENOMEM;
goto out;
}
}
}
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path, &last_extent,
start_slot, ins_nr, 1, 0);
if (ret > 0)
ret = 0;
}
out:
btrfs_release_path(path);
btrfs_free_path(dst_path);
return ret;
}
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx,
const u64 start,
const u64 end)
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
{
struct extent_map *em, *n;
struct list_head extents;
struct extent_map_tree *tree = &inode->extent_tree;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
u64 test_gen;
int ret = 0;
int num = 0;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
INIT_LIST_HEAD(&extents);
write_lock(&tree->lock);
test_gen = root->fs_info->last_trans_committed;
list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
Btrfs: fix missing data checksums after a ranged fsync (msync) Recently we got a massive simplification for fsync, where for the fast path we no longer log new extents while their respective ordered extents are still running. However that simplification introduced a subtle regression for the case where we use a ranged fsync (msync). Consider the following example: CPU 0 CPU 1 mmap write to range [2Mb, 4Mb[ mmap write to range [512Kb, 1Mb[ msync range [512K, 1Mb[ --> triggers fast fsync (BTRFS_INODE_NEEDS_FULL_SYNC not set) --> creates extent map A for this range and adds it to list of modified extents --> starts ordered extent A for this range --> waits for it to complete writeback triggered for range [2Mb, 4Mb[ --> create extent map B and adds it to the list of modified extents --> creates ordered extent B --> start looking for and logging modified extents --> logs extent maps A and B --> finds checksums for extent A in the csum tree, but not for extent B fsync (msync) finishes --> ordered extent B finishes and its checksums are added to the csum tree <power cut> After replaying the log, we have the extent covering the range [2Mb, 4Mb[ but do not have the data checksum items covering that file range. This happens because at the very beginning of an fsync (btrfs_sync_file()) we start and wait for IO in the given range [512Kb, 1Mb[ and therefore wait for any ordered extents in that range to complete before we start logging the extents. However if right before we start logging the extent in our range [512Kb, 1Mb[, writeback is started for any other dirty range, such as the range [2Mb, 4Mb[ due to memory pressure or a concurrent fsync or msync (btrfs_sync_file() starts writeback before acquiring the inode's lock), an ordered extent is created for that other range and a new extent map is created to represent that range and added to the inode's list of modified extents. That means that we will see that other extent in that list when collecting extents for logging (done at btrfs_log_changed_extents()) and log the extent before the respective ordered extent finishes - namely before the checksum items are added to the checksums tree, which is where log_extent_csums() looks for the checksums, therefore making us log an extent without logging its checksums. Before that massive simplification of fsync, this wasn't a problem because besides looking for checkums in the checksums tree, we also looked for them in any ordered extent still running. The consequence of data checksums missing for a file range is that users attempting to read the affected file range will get -EIO errors and dmesg reports the following: [10188.358136] BTRFS info (device sdc): no csum found for inode 297 start 57344 [10188.359278] BTRFS warning (device sdc): csum failed root 5 ino 297 off 57344 csum 0x98f94189 expected csum 0x00000000 mirror 1 So fix this by skipping extents outside of our logging range at btrfs_log_changed_extents() and leaving them on the list of modified extents so that any subsequent ranged fsync may collect them if needed. Also, if we find a hole extent outside of the range still log it, just to prevent having gaps between extent items after replaying the log, otherwise fsck will complain when we are not using the NO_HOLES feature (fstest btrfs/056 triggers such case). Fixes: e7175a692765 ("btrfs: remove the wait ordered logic in the log_one_extent path") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-29 09:42:06 +00:00
/*
* Skip extents outside our logging range. It's important to do
* it for correctness because if we don't ignore them, we may
* log them before their ordered extent completes, and therefore
* we could log them without logging their respective checksums
* (the checksum items are added to the csum tree at the very
* end of btrfs_finish_ordered_io()). Also leave such extents
* outside of our range in the list, since we may have another
* ranged fsync in the near future that needs them. If an extent
* outside our range corresponds to a hole, log it to avoid
* leaving gaps between extents (fsck will complain when we are
* not using the NO_HOLES feature).
*/
if ((em->start > end || em->start + em->len <= start) &&
em->block_start != EXTENT_MAP_HOLE)
continue;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
list_del_init(&em->list);
/*
* Just an arbitrary number, this can be really CPU intensive
* once we start getting a lot of extents, and really once we
* have a bunch of extents we just want to commit since it will
* be faster.
*/
if (++num > 32768) {
list_del_init(&tree->modified_extents);
ret = -EFBIG;
goto process;
}
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
if (em->generation <= test_gen)
continue;
Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-09 15:01:46 +00:00
/* We log prealloc extents beyond eof later. */
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) &&
em->start >= i_size_read(&inode->vfs_inode))
continue;
/* Need a ref to keep it from getting evicted from cache */
refcount_inc(&em->refs);
set_bit(EXTENT_FLAG_LOGGING, &em->flags);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
list_add_tail(&em->list, &extents);
num++;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
}
list_sort(NULL, &extents, extent_cmp);
process:
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
while (!list_empty(&extents)) {
em = list_entry(extents.next, struct extent_map, list);
list_del_init(&em->list);
/*
* If we had an error we just need to delete everybody from our
* private list.
*/
if (ret) {
clear_em_logging(tree, em);
free_extent_map(em);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
continue;
}
write_unlock(&tree->lock);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
ret = log_one_extent(trans, inode, root, em, path, ctx);
write_lock(&tree->lock);
clear_em_logging(tree, em);
free_extent_map(em);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
}
WARN_ON(!list_empty(&extents));
write_unlock(&tree->lock);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
btrfs_release_path(path);
Btrfs: fix duplicate extents after fsync of file with prealloc extents In commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), on fsync, we started to always log all prealloc extents beyond an inode's i_size in order to avoid losing them after a power failure. However under some cases this can lead to the log replay code to create duplicate extent items, with different lengths, in the extent tree. That happens because, as of that commit, we can now log extent items based on extent maps that are not on the "modified" list of extent maps of the inode's extent map tree. Logging extent items based on extent maps is used during the fast fsync path to save time and for this to work reliably it requires that the extent maps are not merged with other adjacent extent maps - having the extent maps in the list of modified extents gives such guarantee. Consider the following example, captured during a long run of fsstress, which illustrates this problem. We have inode 271, in the filesystem tree (root 5), for which all of the following operations and discussion apply to. A buffered write starts at offset 312391 with a length of 933471 bytes (end offset at 1245862). At this point we have, for this inode, the following extent maps with the their field values: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 376832, block_start 1106399232, block_len 376832, orig_block_len 376832 em C, start 417792, orig_start 417792, len 782336, block_start 18446744073709551613, block_len 0, orig_block_len 0 em D, start 1200128, orig_start 1200128, len 835584, block_start 1106776064, block_len 835584, orig_block_len 835584 em E, start 2035712, orig_start 2035712, len 245760, block_start 1107611648, block_len 245760, orig_block_len 245760 Extent map A corresponds to a hole and extent maps D and E correspond to preallocated extents. Extent map D ends where extent map E begins (1106776064 + 835584 = 1107611648), but these extent maps were not merged because they are in the inode's list of modified extent maps. An fsync against this inode is made, which triggers the fast path (BTRFS_INODE_NEEDS_FULL_SYNC is not set). This fsync triggers writeback of the data previously written using buffered IO, and when the respective ordered extent finishes, btrfs_drop_extents() is called against the (aligned) range 311296..1249279. This causes a split of extent map D at btrfs_drop_extent_cache(), replacing extent map D with a new extent map D', also added to the list of modified extents, with the following values: em D', start 1249280, orig_start of 1200128, block_start 1106825216 (= 1106776064 + 1249280 - 1200128), orig_block_len 835584, block_len 786432 (835584 - (1249280 - 1200128)) Then, during the fast fsync, btrfs_log_changed_extents() is called and extent maps D' and E are removed from the list of modified extents. The flag EXTENT_FLAG_LOGGING is also set on them. After the extents are logged clear_em_logging() is called on each of them, and that makes extent map E to be merged with extent map D' (try_merge_map()), resulting in D' being deleted and E adjusted to: em E, start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 A direct IO write at offset 1847296 and length of 360448 bytes (end offset at 2207744) starts, and at that moment the following extent maps exist for our inode: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em E (prealloc), start 1249280, orig_start 1200128, len 1032192, block_start 1106825216, block_len 1032192, orig_block_len 245760 The dio write results in drop_extent_cache() being called twice. The first time for a range that starts at offset 1847296 and ends at offset 2035711 (length of 188416), which results in a double split of extent map E, replacing it with two new extent maps: em F, start 1249280, orig_start 1200128, block_start 1106825216, block_len 598016, orig_block_len 598016 em G, start 2035712, orig_start 1200128, block_start 1107611648, block_len 245760, orig_block_len 1032192 It also creates a new extent map that represents a part of the requested IO (through create_io_em()): em H, start 1847296, len 188416, block_start 1107423232, block_len 188416 The second call to drop_extent_cache() has a range with a start offset of 2035712 and end offset of 2207743 (length of 172032). This leads to replacing extent map G with a new extent map I with the following values: em I, start 2207744, orig_start 1200128, block_start 1107783680, block_len 73728, orig_block_len 1032192 It also creates a new extent map that represents the second part of the requested IO (through create_io_em()): em J, start 2035712, len 172032, block_start 1107611648, block_len 172032 The dio write set the inode's i_size to 2207744 bytes. After the dio write the inode has the following extent maps: em A, start 0, orig_start 0, len 40960, block_start 18446744073709551613, block_len 0, orig_block_len 0 em B, start 40960, orig_start 40960, len 270336, block_start 1106399232, block_len 270336, orig_block_len 376832 em C, start 311296, orig_start 311296, len 937984, block_start 1112842240, block_len 937984, orig_block_len 937984 em F, start 1249280, orig_start 1200128, len 598016, block_start 1106825216, block_len 598016, orig_block_len 598016 em H, start 1847296, orig_start 1200128, len 188416, block_start 1107423232, block_len 188416, orig_block_len 835584 em J, start 2035712, orig_start 2035712, len 172032, block_start 1107611648, block_len 172032, orig_block_len 245760 em I, start 2207744, orig_start 1200128, len 73728, block_start 1107783680, block_len 73728, orig_block_len 1032192 Now do some change to the file, like adding a xattr for example and then fsync it again. This triggers a fast fsync path, and as of commit 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay"), we use the extent map I to log a file extent item because it's a prealloc extent and it starts at an offset matching the inode's i_size. However when we log it, we create a file extent item with a value for the disk byte location that is wrong, as can be seen from the following output of "btrfs inspect-internal dump-tree": item 1 key (271 EXTENT_DATA 2207744) itemoff 3782 itemsize 53 generation 22 type 2 (prealloc) prealloc data disk byte 1106776064 nr 1032192 prealloc data offset 1007616 nr 73728 Here the disk byte value corresponds to calculation based on some fields from the extent map I: 1106776064 = block_start (1107783680) - 1007616 (extent_offset) extent_offset = 2207744 (start) - 1200128 (orig_start) = 1007616 The disk byte value of 1106776064 clashes with disk byte values of the file extent items at offsets 1249280 and 1847296 in the fs tree: item 6 key (271 EXTENT_DATA 1249280) itemoff 3568 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1106776064 nr 835584 prealloc data offset 49152 nr 598016 item 7 key (271 EXTENT_DATA 1847296) itemoff 3515 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1106776064 nr 835584 extent data offset 647168 nr 188416 ram 835584 extent compression 0 (none) item 8 key (271 EXTENT_DATA 2035712) itemoff 3462 itemsize 53 generation 20 type 1 (regular) extent data disk byte 1107611648 nr 245760 extent data offset 0 nr 172032 ram 245760 extent compression 0 (none) item 9 key (271 EXTENT_DATA 2207744) itemoff 3409 itemsize 53 generation 20 type 2 (prealloc) prealloc data disk byte 1107611648 nr 245760 prealloc data offset 172032 nr 73728 Instead of the disk byte value of 1106776064, the value of 1107611648 should have been logged. Also the data offset value should have been 172032 and not 1007616. After a log replay we end up getting two extent items in the extent tree with different lengths, one of 835584, which is correct and existed before the log replay, and another one of 1032192 which is wrong and is based on the logged file extent item: item 12 key (1106776064 EXTENT_ITEM 835584) itemoff 3406 itemsize 53 refs 2 gen 15 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 2 item 13 key (1106776064 EXTENT_ITEM 1032192) itemoff 3353 itemsize 53 refs 1 gen 22 flags DATA extent data backref root 5 objectid 271 offset 1200128 count 1 Obviously this leads to many problems and a filesystem check reports many errors: (...) checking extents Extent back ref already exists for 1106776064 parent 0 root 5 owner 271 offset 1200128 num_refs 1 extent item 1106776064 has multiple extent items ref mismatch on [1106776064 835584] extent item 2, found 3 Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 2 wanted 1 back 0x55b1d0ad7680 Backref 1106776064 root 5 owner 271 offset 1200128 num_refs 0 not found in extent tree Incorrect local backref count on 1106776064 root 5 owner 271 offset 1200128 found 1 wanted 0 back 0x55b1d0ad4e70 Backref bytes do not match extent backref, bytenr=1106776064, ref bytes=835584, backref bytes=1032192 backpointer mismatch on [1106776064 835584] checking free space cache block group 1103101952 has wrong amount of free space failed to load free space cache for block group 1103101952 checking fs roots (...) So fix this by logging the prealloc extents beyond the inode's i_size based on searches in the subvolume tree instead of the extent maps. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-09 15:01:46 +00:00
if (!ret)
ret = btrfs_log_prealloc_extents(trans, inode, path);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
return ret;
}
static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
struct btrfs_path *path, u64 *size_ret)
{
struct btrfs_key key;
int ret;
key.objectid = btrfs_ino(inode);
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
if (ret < 0) {
return ret;
} else if (ret > 0) {
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
*size_ret = 0;
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
} else {
struct btrfs_inode_item *item;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
*size_ret = btrfs_inode_size(path->nodes[0], item);
Btrfs: fix incorrect file size after shrinking truncate and fsync If we do a shrinking truncate against an inode which is already present in the respective log tree and then rename it, as part of logging the new name we end up logging an inode item that reflects the old size of the file (the one which we previously logged) and not the new smaller size. The decision to preserve the size previously logged was added by commit 1a4bcf470c886b ("Btrfs: fix fsync data loss after adding hard link to inode") in order to avoid data loss after replaying the log. However that decision is only needed for the case the logged inode size is smaller then the current size of the inode, as explained in that commit's change log. If the current size of the inode is smaller then the previously logged size, we know a shrinking truncate happened and therefore need to use that smaller size. Example to trigger the problem: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 8000" /mnt/foo $ xfs_io -c "fsync" /mnt/foo $ xfs_io -c "truncate 3000" /mnt/foo $ mv /mnt/foo /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power failure> $ mount /dev/sdb /mnt $ od -t x1 -A d /mnt/bar 0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 0008000 Once we rename the file, we log its name (and inode item), and because the inode was already logged before in the current transaction, we log it with a size of 8000 bytes because that is the size we previously logged (with the first fsync). As part of the rename, besides logging the inode, we do also sync the log, which is done since commit d4682ba03ef618 ("Btrfs: sync log after logging new name"), so the next fsync against our inode is effectively a no-op, since no new changes happened since the rename operation. Even if did not sync the log during the rename operation, the same problem (fize size of 8000 bytes instead of 3000 bytes) would be visible after replaying the log if the log ended up getting synced to disk through some other means, such as for example by fsyncing some other modified file. In the example above the fsync after the rename operation is there just because not every filesystem may guarantee logging/journalling the inode (and syncing the log/journal) during the rename operation, for example it is needed for f2fs, but not for ext4 and xfs. Fix this scenario by, when logging a new name (which is triggered by rename and link operations), using the current size of the inode instead of the previously logged inode size. A test case for fstests follows soon. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202695 CC: stable@vger.kernel.org # 4.4+ Reported-by: Seulbae Kim <seulbae@gatech.edu> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-04 14:06:12 +00:00
/*
* If the in-memory inode's i_size is smaller then the inode
* size stored in the btree, return the inode's i_size, so
* that we get a correct inode size after replaying the log
* when before a power failure we had a shrinking truncate
* followed by addition of a new name (rename / new hard link).
* Otherwise return the inode size from the btree, to avoid
* data loss when replaying a log due to previously doing a
* write that expands the inode's size and logging a new name
* immediately after.
*/
if (*size_ret > inode->vfs_inode.i_size)
*size_ret = inode->vfs_inode.i_size;
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
}
btrfs_release_path(path);
return 0;
}
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
/*
* At the moment we always log all xattrs. This is to figure out at log replay
* time which xattrs must have their deletion replayed. If a xattr is missing
* in the log tree and exists in the fs/subvol tree, we delete it. This is
* because if a xattr is deleted, the inode is fsynced and a power failure
* happens, causing the log to be replayed the next time the fs is mounted,
* we want the xattr to not exist anymore (same behaviour as other filesystems
* with a journal, ext3/4, xfs, f2fs, etc).
*/
static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
struct btrfs_path *path,
struct btrfs_path *dst_path)
{
int ret;
struct btrfs_key key;
const u64 ino = btrfs_ino(inode);
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
int ins_nr = 0;
int start_slot = 0;
key.objectid = ino;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
while (true) {
int slot = path->slots[0];
struct extent_buffer *leaf = path->nodes[0];
int nritems = btrfs_header_nritems(leaf);
if (slot >= nritems) {
if (ins_nr > 0) {
u64 last_extent = 0;
ret = copy_items(trans, inode, dst_path, path,
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
&last_extent, start_slot,
ins_nr, 1, 0);
/* can't be 1, extent items aren't processed */
ASSERT(ret <= 0);
if (ret < 0)
return ret;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
break;
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
cond_resched();
}
if (ins_nr > 0) {
u64 last_extent = 0;
ret = copy_items(trans, inode, dst_path, path,
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
&last_extent, start_slot,
ins_nr, 1, 0);
/* can't be 1, extent items aren't processed */
ASSERT(ret <= 0);
if (ret < 0)
return ret;
}
return 0;
}
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
/*
* If the no holes feature is enabled we need to make sure any hole between the
* last extent and the i_size of our inode is explicitly marked in the log. This
* is to make sure that doing something like:
*
* 1) create file with 128Kb of data
* 2) truncate file to 64Kb
* 3) truncate file to 256Kb
* 4) fsync file
* 5) <crash/power failure>
* 6) mount fs and trigger log replay
*
* Will give us a file with a size of 256Kb, the first 64Kb of data match what
* the file had in its first 64Kb of data at step 1 and the last 192Kb of the
* file correspond to a hole. The presence of explicit holes in a log tree is
* what guarantees that log replay will remove/adjust file extent items in the
* fs/subvol tree.
*
* Here we do not need to care about holes between extents, that is already done
* by copy_items(). We also only need to do this in the full sync path, where we
* lookup for extents from the fs/subvol tree only. In the fast path case, we
* lookup the list of modified extent maps and if any represents a hole, we
* insert a corresponding extent representing a hole in the log tree.
*/
static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *inode,
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
struct btrfs_path *path)
{
struct btrfs_fs_info *fs_info = root->fs_info;
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
int ret;
struct btrfs_key key;
u64 hole_start;
u64 hole_size;
struct extent_buffer *leaf;
struct btrfs_root *log = root->log_root;
const u64 ino = btrfs_ino(inode);
const u64 i_size = i_size_read(&inode->vfs_inode);
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
if (!btrfs_fs_incompat(fs_info, NO_HOLES))
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
ASSERT(ret != 0);
if (ret < 0)
return ret;
ASSERT(path->slots[0] > 0);
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
/* inode does not have any extents */
hole_start = 0;
hole_size = i_size;
} else {
struct btrfs_file_extent_item *extent;
u64 len;
/*
* If there's an extent beyond i_size, an explicit hole was
* already inserted by copy_items().
*/
if (key.offset >= i_size)
return 0;
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, extent) ==
Btrfs: fix assertion failure on fsync with NO_HOLES enabled Back in commit a89ca6f24ffe4 ("Btrfs: fix fsync after truncate when no_holes feature is enabled") I added an assertion that is triggered when an inline extent is found to assert that the length of the (uncompressed) data the extent represents is the same as the i_size of the inode, since that is true most of the time I couldn't find or didn't remembered about any exception at that time. Later on the assertion was expanded twice to deal with a case of a compressed inline extent representing a range that matches the sector size followed by an expanding truncate, and another case where fallocate can update the i_size of the inode without adding or updating existing extents (if the fallocate range falls entirely within the first block of the file). These two expansion/fixes of the assertion were done by commit 7ed586d0a8241 ("Btrfs: fix assertion on fsync of regular file when using no-holes feature") and commit 6399fb5a0b69a ("Btrfs: fix assertion failure during fsync in no-holes mode"). These however missed the case where an falloc expands the i_size of an inode to exactly the sector size and inline extent exists, for example: $ mkfs.btrfs -f -O no-holes /dev/sdc $ mount /dev/sdc /mnt $ xfs_io -f -c "pwrite -S 0xab 0 1096" /mnt/foobar wrote 1096/1096 bytes at offset 0 1 KiB, 1 ops; 0.0002 sec (4.448 MiB/sec and 4255.3191 ops/sec) $ xfs_io -c "falloc 1096 3000" /mnt/foobar $ xfs_io -c "fsync" /mnt/foobar Segmentation fault $ dmesg [701253.602385] assertion failed: len == i_size || (len == fs_info->sectorsize && btrfs_file_extent_compression(leaf, extent) != BTRFS_COMPRESS_NONE) || (len < i_size && i_size < fs_info->sectorsize), file: fs/btrfs/tree-log.c, line: 4727 [701253.602962] ------------[ cut here ]------------ [701253.603224] kernel BUG at fs/btrfs/ctree.h:3533! [701253.603503] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [701253.603774] CPU: 2 PID: 7192 Comm: xfs_io Tainted: G W 5.0.0-rc8-btrfs-next-45 #1 [701253.604054] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [701253.604650] RIP: 0010:assfail.constprop.23+0x18/0x1a [btrfs] (...) [701253.605591] RSP: 0018:ffffbb48c186bc48 EFLAGS: 00010286 [701253.605914] RAX: 00000000000000de RBX: ffff921d0a7afc08 RCX: 0000000000000000 [701253.606244] RDX: 0000000000000000 RSI: ffff921d36b16868 RDI: ffff921d36b16868 [701253.606580] RBP: ffffbb48c186bcf0 R08: 0000000000000000 R09: 0000000000000000 [701253.606913] R10: 0000000000000003 R11: 0000000000000000 R12: ffff921d05d2de18 [701253.607247] R13: ffff921d03b54000 R14: 0000000000000448 R15: ffff921d059ecf80 [701253.607769] FS: 00007f14da906700(0000) GS:ffff921d36b00000(0000) knlGS:0000000000000000 [701253.608163] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [701253.608516] CR2: 000056087ea9f278 CR3: 00000002268e8001 CR4: 00000000003606e0 [701253.608880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [701253.609250] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [701253.609608] Call Trace: [701253.609994] btrfs_log_inode+0xdfb/0xe40 [btrfs] [701253.610383] btrfs_log_inode_parent+0x2be/0xa60 [btrfs] [701253.610770] ? do_raw_spin_unlock+0x49/0xc0 [701253.611150] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [701253.611537] btrfs_sync_file+0x3b2/0x440 [btrfs] [701253.612010] ? do_sysinfo+0xb0/0xf0 [701253.612552] do_fsync+0x38/0x60 [701253.612988] __x64_sys_fsync+0x10/0x20 [701253.613360] do_syscall_64+0x60/0x1b0 [701253.613733] entry_SYSCALL_64_after_hwframe+0x49/0xbe [701253.614103] RIP: 0033:0x7f14da4e66d0 (...) [701253.615250] RSP: 002b:00007fffa670fdb8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a [701253.615647] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f14da4e66d0 [701253.616047] RDX: 000056087ea9c260 RSI: 000056087ea9c260 RDI: 0000000000000003 [701253.616450] RBP: 0000000000000001 R08: 0000000000000020 R09: 0000000000000010 [701253.616854] R10: 000000000000009b R11: 0000000000000246 R12: 000056087ea9c260 [701253.617257] R13: 000056087ea9c240 R14: 0000000000000000 R15: 000056087ea9dd10 (...) [701253.619941] ---[ end trace e088d74f132b6da5 ]--- Updating the assertion again to allow for this particular case would result in a meaningless assertion, plus there is currently no risk of logging content that would result in any corruption after a log replay if the size of the data encoded in an inline extent is greater than the inode's i_size (which is not currently possibe either with or without compression), therefore just remove the assertion. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-19 17:18:13 +00:00
BTRFS_FILE_EXTENT_INLINE)
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
return 0;
len = btrfs_file_extent_num_bytes(leaf, extent);
/* Last extent goes beyond i_size, no need to log a hole. */
if (key.offset + len > i_size)
return 0;
hole_start = key.offset + len;
hole_size = i_size - hole_start;
}
btrfs_release_path(path);
/* Last extent ends at i_size. */
if (hole_size == 0)
return 0;
hole_size = ALIGN(hole_size, fs_info->sectorsize);
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
ret = btrfs_insert_file_extent(trans, log, ino, hole_start, 0, 0,
hole_size, 0, hole_size, 0, 0, 0);
return ret;
}
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
/*
* When we are logging a new inode X, check if it doesn't have a reference that
* matches the reference from some other inode Y created in a past transaction
* and that was renamed in the current transaction. If we don't do this, then at
* log replay time we can lose inode Y (and all its files if it's a directory):
*
* mkdir /mnt/x
* echo "hello world" > /mnt/x/foobar
* sync
* mv /mnt/x /mnt/y
* mkdir /mnt/x # or touch /mnt/x
* xfs_io -c fsync /mnt/x
* <power fail>
* mount fs, trigger log replay
*
* After the log replay procedure, we would lose the first directory and all its
* files (file foobar).
* For the case where inode Y is not a directory we simply end up losing it:
*
* echo "123" > /mnt/foo
* sync
* mv /mnt/foo /mnt/bar
* echo "abc" > /mnt/foo
* xfs_io -c fsync /mnt/foo
* <power fail>
*
* We also need this for cases where a snapshot entry is replaced by some other
* entry (file or directory) otherwise we end up with an unreplayable log due to
* attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
* if it were a regular entry:
*
* mkdir /mnt/x
* btrfs subvolume snapshot /mnt /mnt/x/snap
* btrfs subvolume delete /mnt/x/snap
* rmdir /mnt/x
* mkdir /mnt/x
* fsync /mnt/x or fsync some new file inside it
* <power fail>
*
* The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
* the same transaction.
*/
static int btrfs_check_ref_name_override(struct extent_buffer *eb,
const int slot,
const struct btrfs_key *key,
struct btrfs_inode *inode,
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
u64 *other_ino, u64 *other_parent)
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
{
int ret;
struct btrfs_path *search_path;
char *name = NULL;
u32 name_len = 0;
u32 item_size = btrfs_item_size_nr(eb, slot);
u32 cur_offset = 0;
unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
search_path = btrfs_alloc_path();
if (!search_path)
return -ENOMEM;
search_path->search_commit_root = 1;
search_path->skip_locking = 1;
while (cur_offset < item_size) {
u64 parent;
u32 this_name_len;
u32 this_len;
unsigned long name_ptr;
struct btrfs_dir_item *di;
if (key->type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *iref;
iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
parent = key->offset;
this_name_len = btrfs_inode_ref_name_len(eb, iref);
name_ptr = (unsigned long)(iref + 1);
this_len = sizeof(*iref) + this_name_len;
} else {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)(ptr +
cur_offset);
parent = btrfs_inode_extref_parent(eb, extref);
this_name_len = btrfs_inode_extref_name_len(eb, extref);
name_ptr = (unsigned long)&extref->name;
this_len = sizeof(*extref) + this_name_len;
}
if (this_name_len > name_len) {
char *new_name;
new_name = krealloc(name, this_name_len, GFP_NOFS);
if (!new_name) {
ret = -ENOMEM;
goto out;
}
name_len = this_name_len;
name = new_name;
}
read_extent_buffer(eb, name, name_ptr, this_name_len);
di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
parent, name, this_name_len, 0);
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
if (di && !IS_ERR(di)) {
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
struct btrfs_key di_key;
btrfs_dir_item_key_to_cpu(search_path->nodes[0],
di, &di_key);
if (di_key.type == BTRFS_INODE_ITEM_KEY) {
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
if (di_key.objectid != key->objectid) {
ret = 1;
*other_ino = di_key.objectid;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
*other_parent = parent;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
} else {
ret = 0;
}
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
} else {
ret = -EAGAIN;
}
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
goto out;
} else if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
btrfs_release_path(search_path);
cur_offset += this_len;
}
ret = 0;
out:
btrfs_free_path(search_path);
kfree(name);
return ret;
}
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
struct btrfs_ino_list {
u64 ino;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
u64 parent;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
struct list_head list;
};
static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx,
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
u64 ino, u64 parent)
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
{
struct btrfs_ino_list *ino_elem;
LIST_HEAD(inode_list);
int ret = 0;
ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
if (!ino_elem)
return -ENOMEM;
ino_elem->ino = ino;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
ino_elem->parent = parent;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
list_add_tail(&ino_elem->list, &inode_list);
while (!list_empty(&inode_list)) {
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
struct inode *inode;
ino_elem = list_first_entry(&inode_list, struct btrfs_ino_list,
list);
ino = ino_elem->ino;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
parent = ino_elem->parent;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
list_del(&ino_elem->list);
kfree(ino_elem);
if (ret)
continue;
btrfs_release_path(path);
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, root, NULL);
/*
* If the other inode that had a conflicting dir entry was
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
* deleted in the current transaction, we need to log its parent
* directory.
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
*/
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
if (ret == -ENOENT) {
key.objectid = parent;
inode = btrfs_iget(fs_info->sb, &key, root,
NULL);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
} else {
ret = btrfs_log_inode(trans, root,
BTRFS_I(inode),
LOG_OTHER_INODE_ALL,
0, LLONG_MAX, ctx);
iput(inode);
}
}
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
continue;
}
/*
* We are safe logging the other inode without acquiring its
* lock as long as we log with the LOG_INODE_EXISTS mode. We
* are safe against concurrent renames of the other inode as
* well because during a rename we pin the log and update the
* log with the new name before we unpin it.
*/
ret = btrfs_log_inode(trans, root, BTRFS_I(inode),
LOG_OTHER_INODE, 0, LLONG_MAX, ctx);
if (ret) {
iput(inode);
continue;
}
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
iput(inode);
continue;
}
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
u64 other_ino = 0;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
u64 other_parent = 0;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
break;
} else if (ret > 0) {
ret = 0;
break;
}
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino ||
(key.type != BTRFS_INODE_REF_KEY &&
key.type != BTRFS_INODE_EXTREF_KEY)) {
ret = 0;
break;
}
ret = btrfs_check_ref_name_override(leaf, slot, &key,
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
BTRFS_I(inode), &other_ino,
&other_parent);
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
if (ret < 0)
break;
if (ret > 0) {
ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
if (!ino_elem) {
ret = -ENOMEM;
break;
}
ino_elem->ino = other_ino;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
ino_elem->parent = other_parent;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
list_add_tail(&ino_elem->list, &inode_list);
ret = 0;
}
path->slots[0]++;
}
iput(inode);
}
return ret;
}
/* log a single inode in the tree log.
* At least one parent directory for this inode must exist in the tree
* or be logged already.
*
* Any items from this inode changed by the current transaction are copied
* to the log tree. An extra reference is taken on any extents in this
* file, allowing us to avoid a whole pile of corner cases around logging
* blocks that have been removed from the tree.
*
* See LOG_INODE_ALL and related defines for a description of what inode_only
* does.
*
* This handles both files and directories.
*/
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_inode *inode,
int inode_only,
const loff_t start,
Btrfs: fix data corruption after fast fsync and writeback error When we do a fast fsync, we start all ordered operations and then while they're running in parallel we visit the list of modified extent maps and construct their matching file extent items and write them to the log btree. After that, in btrfs_sync_log() we wait for all the ordered operations to finish (via btrfs_wait_logged_extents). The problem with this is that we were completely ignoring errors that can happen in the extent write path, such as -ENOSPC, a temporary -ENOMEM or -EIO errors for example. When such error happens, it means we have parts of the on disk extent that weren't written to, and so we end up logging file extent items that point to these extents that contain garbage/random data - so after a crash/reboot plus log replay, we get our inode's metadata pointing to those extents. This worked in contrast with the full (non-fast) fsync path, where we start all ordered operations, wait for them to finish and then write to the log btree. In this path, after each ordered operation completes we check if it's flagged with an error (BTRFS_ORDERED_IOERR) and return -EIO if so (via btrfs_wait_ordered_range). So if an error happens with any ordered operation, just return a -EIO error to userspace, so that it knows that not all of its previous writes were durably persisted and the application can take proper action (like redo the writes for e.g.) - and definitely not leave any file extent items in the log refer to non fully written extents. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-05 14:14:39 +00:00
const loff_t end,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct btrfs_path *dst_path;
struct btrfs_key min_key;
struct btrfs_key max_key;
struct btrfs_root *log = root->log_root;
u64 last_extent = 0;
int err = 0;
int ret;
int nritems;
int ins_start_slot = 0;
int ins_nr;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
bool fast_search = false;
u64 ino = btrfs_ino(inode);
struct extent_map_tree *em_tree = &inode->extent_tree;
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
u64 logged_isize = 0;
Btrfs: fix fsync data loss after append write If we do an append write to a file (which increases its inode's i_size) that does not have the flag BTRFS_INODE_NEEDS_FULL_SYNC set in its inode, and the previous transaction added a new hard link to the file, which sets the flag BTRFS_INODE_COPY_EVERYTHING in the file's inode, and then fsync the file, the inode's new i_size isn't logged. This has the consequence that after the fsync log is replayed, the file size remains what it was before the append write operation, which means users/applications will not be able to read the data that was successsfully fsync'ed before. This happens because neither the inode item nor the delayed inode get their i_size updated when the append write is made - doing so would require starting a transaction in the buffered write path, something that we do not do intentionally for performance reasons. Fix this by making sure that when the flag BTRFS_INODE_COPY_EVERYTHING is set the inode is logged with its current i_size (log the in-memory inode into the log tree). This issue is not a recent regression and is easy to reproduce with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs generic _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and then fsync it. # The fsync here is only needed to trigger the issue in btrfs, as it causes the # the flag BTRFS_INODE_NEEDS_FULL_SYNC to be removed from the btrfs inode. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io sync # Add a hard link to our file. # On btrfs this sets the flag BTRFS_INODE_COPY_EVERYTHING on the btrfs inode, # which is a necessary condition to trigger the issue. ln $SCRATCH_MNT/foo $SCRATCH_MNT/bar # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now append more data to our file, increasing its size, and fsync the file. # In btrfs because the inode flag BTRFS_INODE_COPY_EVERYTHING was set and the # write path did not update the inode item in the btree nor the delayed inode # item (in memory struture) in the current transaction (created by the fsync # handler), the fsync did not record the inode's new i_size in the fsync # log/journal. This made the data unavailable after the fsync log/journal is # replayed. $XFS_IO_PROG -c "pwrite -S 0xbb 32K 32K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io echo "File content after fsync and before crash:" od -t x1 $SCRATCH_MNT/foo _crash_and_mount echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo status=0 exit The expected file output before and after the crash/power failure expects the appended data to be available, which is: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0100000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0200000 Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-17 11:49:23 +00:00
bool need_log_inode_item = true;
bool xattrs_logged = false;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
bool recursive_logging = false;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dst_path = btrfs_alloc_path();
if (!dst_path) {
btrfs_free_path(path);
return -ENOMEM;
}
min_key.objectid = ino;
min_key.type = BTRFS_INODE_ITEM_KEY;
min_key.offset = 0;
max_key.objectid = ino;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
/* today the code can only do partial logging of directories */
if (S_ISDIR(inode->vfs_inode.i_mode) ||
(!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags) &&
inode_only >= LOG_INODE_EXISTS))
max_key.type = BTRFS_XATTR_ITEM_KEY;
else
max_key.type = (u8)-1;
max_key.offset = (u64)-1;
Btrfs: fix fsync when extend references are added to an inode If we added an extended reference to an inode and fsync'ed it, the log replay code would make our inode have an incorrect link count, which was lower then the expected/correct count. This resulted in stale directory index entries after deleting some of the hard links, and any access to the dangling directory entries resulted in -ESTALE errors because the entries pointed to inode items that don't exist anymore. This is easy to reproduce with the test case I made for xfstests, and the bulk of that test is: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Add one more link to the inode that ends up being a btrfs extref and fsync # the inode. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now after the fsync log replay btrfs left our inode with a wrong link count N, # which was smaller than the correct link count M (N < M). # So after removing N hard links, the remaining M - N directory entries were # still visible to user space but it was impossible to do anything with them # because they pointed to an inode that didn't exist anymore. This resulted in # stale file handle errors (-ESTALE) when accessing those dentries for example. # # So remove all hard links except the first one and then attempt to read the # file, to verify we don't get an -ESTALE error when accessing the inodel # # The btrfs fsck tool also detected the incorrect inode link count and it # reported an error message like the following: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref # # The fstests framework automatically calls fsck after a test is run, so we # don't need to call fsck explicitly here. rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo status=0 exit So make sure an fsync always flushes the delayed inode item, so that the fsync log contains it (needed in order to trigger the link count fixup code) and fix the extref counting function, which always return -ENOENT to its caller (and made it assume there were always 0 extrefs). This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-13 16:40:04 +00:00
/*
* Only run delayed items if we are a dir or a new file.
* Otherwise commit the delayed inode only, which is needed in
* order for the log replay code to mark inodes for link count
* fixup (create temporary BTRFS_TREE_LOG_FIXUP_OBJECTID items).
*/
if (S_ISDIR(inode->vfs_inode.i_mode) ||
inode->generation > fs_info->last_trans_committed)
ret = btrfs_commit_inode_delayed_items(trans, inode);
Btrfs: fix fsync when extend references are added to an inode If we added an extended reference to an inode and fsync'ed it, the log replay code would make our inode have an incorrect link count, which was lower then the expected/correct count. This resulted in stale directory index entries after deleting some of the hard links, and any access to the dangling directory entries resulted in -ESTALE errors because the entries pointed to inode items that don't exist anymore. This is easy to reproduce with the test case I made for xfstests, and the bulk of that test is: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Add one more link to the inode that ends up being a btrfs extref and fsync # the inode. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now after the fsync log replay btrfs left our inode with a wrong link count N, # which was smaller than the correct link count M (N < M). # So after removing N hard links, the remaining M - N directory entries were # still visible to user space but it was impossible to do anything with them # because they pointed to an inode that didn't exist anymore. This resulted in # stale file handle errors (-ESTALE) when accessing those dentries for example. # # So remove all hard links except the first one and then attempt to read the # file, to verify we don't get an -ESTALE error when accessing the inodel # # The btrfs fsck tool also detected the incorrect inode link count and it # reported an error message like the following: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref # # The fstests framework automatically calls fsck after a test is run, so we # don't need to call fsck explicitly here. rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo status=0 exit So make sure an fsync always flushes the delayed inode item, so that the fsync log contains it (needed in order to trigger the link count fixup code) and fix the extref counting function, which always return -ENOENT to its caller (and made it assume there were always 0 extrefs). This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-13 16:40:04 +00:00
else
ret = btrfs_commit_inode_delayed_inode(inode);
Btrfs: fix fsync when extend references are added to an inode If we added an extended reference to an inode and fsync'ed it, the log replay code would make our inode have an incorrect link count, which was lower then the expected/correct count. This resulted in stale directory index entries after deleting some of the hard links, and any access to the dangling directory entries resulted in -ESTALE errors because the entries pointed to inode items that don't exist anymore. This is easy to reproduce with the test case I made for xfstests, and the bulk of that test is: _scratch_mkfs "-O extref" >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create a test file with 3001 hard links. This number is large enough to # make btrfs start using extrefs at some point even if the fs has the maximum # possible leaf/node size (64Kb). echo "hello world" > $SCRATCH_MNT/foo for i in `seq 1 3000`; do ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i` done # Make sure all metadata and data are durably persisted. sync # Add one more link to the inode that ends up being a btrfs extref and fsync # the inode. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Simulate a crash/power loss. This makes sure the next mount # will see an fsync log and will replay that log. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Now after the fsync log replay btrfs left our inode with a wrong link count N, # which was smaller than the correct link count M (N < M). # So after removing N hard links, the remaining M - N directory entries were # still visible to user space but it was impossible to do anything with them # because they pointed to an inode that didn't exist anymore. This resulted in # stale file handle errors (-ESTALE) when accessing those dentries for example. # # So remove all hard links except the first one and then attempt to read the # file, to verify we don't get an -ESTALE error when accessing the inodel # # The btrfs fsck tool also detected the incorrect inode link count and it # reported an error message like the following: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 256 index 2978 namelen 13 name foo_link_2976 filetype 1 errors 4, no inode ref # # The fstests framework automatically calls fsck after a test is run, so we # don't need to call fsck explicitly here. rm -f $SCRATCH_MNT/foo_link_* cat $SCRATCH_MNT/foo status=0 exit So make sure an fsync always flushes the delayed inode item, so that the fsync log contains it (needed in order to trigger the link count fixup code) and fix the extref counting function, which always return -ENOENT to its caller (and made it assume there were always 0 extrefs). This issue has been present since the introduction of the extrefs feature (2012). A test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-13 16:40:04 +00:00
if (ret) {
btrfs_free_path(path);
btrfs_free_path(dst_path);
return ret;
btrfs: implement delayed inode items operation Changelog V5 -> V6: - Fix oom when the memory load is high, by storing the delayed nodes into the root's radix tree, and letting btrfs inodes go. Changelog V4 -> V5: - Fix the race on adding the delayed node to the inode, which is spotted by Chris Mason. - Merge Chris Mason's incremental patch into this patch. - Fix deadlock between readdir() and memory fault, which is reported by Itaru Kitayama. Changelog V3 -> V4: - Fix nested lock, which is reported by Itaru Kitayama, by updating space cache inode in time. Changelog V2 -> V3: - Fix the race between the delayed worker and the task which does delayed items balance, which is reported by Tsutomu Itoh. - Modify the patch address David Sterba's comment. - Fix the bug of the cpu recursion spinlock, reported by Chris Mason Changelog V1 -> V2: - break up the global rb-tree, use a list to manage the delayed nodes, which is created for every directory and file, and used to manage the delayed directory name index items and the delayed inode item. - introduce a worker to deal with the delayed nodes. Compare with Ext3/4, the performance of file creation and deletion on btrfs is very poor. the reason is that btrfs must do a lot of b+ tree insertions, such as inode item, directory name item, directory name index and so on. If we can do some delayed b+ tree insertion or deletion, we can improve the performance, so we made this patch which implemented delayed directory name index insertion/deletion and delayed inode update. Implementation: - introduce a delayed root object into the filesystem, that use two lists to manage the delayed nodes which are created for every file/directory. One is used to manage all the delayed nodes that have delayed items. And the other is used to manage the delayed nodes which is waiting to be dealt with by the work thread. - Every delayed node has two rb-tree, one is used to manage the directory name index which is going to be inserted into b+ tree, and the other is used to manage the directory name index which is going to be deleted from b+ tree. - introduce a worker to deal with the delayed operation. This worker is used to deal with the works of the delayed directory name index items insertion and deletion and the delayed inode update. When the delayed items is beyond the lower limit, we create works for some delayed nodes and insert them into the work queue of the worker, and then go back. When the delayed items is beyond the upper bound, we create works for all the delayed nodes that haven't been dealt with, and insert them into the work queue of the worker, and then wait for that the untreated items is below some threshold value. - When we want to insert a directory name index into b+ tree, we just add the information into the delayed inserting rb-tree. And then we check the number of the delayed items and do delayed items balance. (The balance policy is above.) - When we want to delete a directory name index from the b+ tree, we search it in the inserting rb-tree at first. If we look it up, just drop it. If not, add the key of it into the delayed deleting rb-tree. Similar to the delayed inserting rb-tree, we also check the number of the delayed items and do delayed items balance. (The same to inserting manipulation) - When we want to update the metadata of some inode, we cached the data of the inode into the delayed node. the worker will flush it into the b+ tree after dealing with the delayed insertion and deletion. - We will move the delayed node to the tail of the list after we access the delayed node, By this way, we can cache more delayed items and merge more inode updates. - If we want to commit transaction, we will deal with all the delayed node. - the delayed node will be freed when we free the btrfs inode. - Before we log the inode items, we commit all the directory name index items and the delayed inode update. I did a quick test by the benchmark tool[1] and found we can improve the performance of file creation by ~15%, and file deletion by ~20%. Before applying this patch: Create files: Total files: 50000 Total time: 1.096108 Average time: 0.000022 Delete files: Total files: 50000 Total time: 1.510403 Average time: 0.000030 After applying this patch: Create files: Total files: 50000 Total time: 0.932899 Average time: 0.000019 Delete files: Total files: 50000 Total time: 1.215732 Average time: 0.000024 [1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3 Many thanks for Kitayama-san's help! Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: David Sterba <dave@jikos.cz> Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Tested-by: Itaru Kitayama <kitayama@cl.bb4u.ne.jp> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-04-22 10:12:22 +00:00
}
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
if (inode_only == LOG_OTHER_INODE || inode_only == LOG_OTHER_INODE_ALL) {
recursive_logging = true;
if (inode_only == LOG_OTHER_INODE)
inode_only = LOG_INODE_EXISTS;
else
inode_only = LOG_INODE_ALL;
mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING);
} else {
mutex_lock(&inode->log_mutex);
}
/*
* a brute force approach to making sure we get the most uptodate
* copies of everything.
*/
if (S_ISDIR(inode->vfs_inode.i_mode)) {
int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
if (inode_only == LOG_INODE_EXISTS)
max_key_type = BTRFS_XATTR_ITEM_KEY;
ret = drop_objectid_items(trans, log, path, ino, max_key_type);
} else {
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
if (inode_only == LOG_INODE_EXISTS) {
/*
* Make sure the new inode item we write to the log has
* the same isize as the current one (if it exists).
* This is necessary to prevent data loss after log
* replay, and also to prevent doing a wrong expanding
* truncate - for e.g. create file, write 4K into offset
* 0, fsync, write 4K into offset 4096, add hard link,
* fsync some other file (to sync log), power fail - if
* we use the inode's current i_size, after log replay
* we get a 8Kb file, with the last 4Kb extent as a hole
* (zeroes), as if an expanding truncate happened,
* instead of getting a file of 4Kb only.
*/
err = logged_inode_size(log, inode, path, &logged_isize);
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
if (err)
goto out_unlock;
}
Btrfs: don't remove extents and xattrs when logging new names If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 16:56:14 +00:00
if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags)) {
Btrfs: don't remove extents and xattrs when logging new names If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 16:56:14 +00:00
if (inode_only == LOG_INODE_EXISTS) {
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
max_key.type = BTRFS_XATTR_ITEM_KEY;
Btrfs: don't remove extents and xattrs when logging new names If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 16:56:14 +00:00
ret = drop_objectid_items(trans, log, path, ino,
max_key.type);
} else {
clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags);
Btrfs: don't remove extents and xattrs when logging new names If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 16:56:14 +00:00
clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags);
while(1) {
ret = btrfs_truncate_inode_items(trans,
log, &inode->vfs_inode, 0, 0);
if (ret != -EAGAIN)
break;
}
Btrfs: don't remove extents and xattrs when logging new names If we are recording in the tree log that an inode has new names (new hard links were added), we would drop items, belonging to the inode, that we shouldn't: 1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the extent and xattr items that were previously logged. This was done only in memory, since logging a new name doesn't imply syncing the log; 2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime flags, we ended up dropping all the xattr items that were previously logged. Like the case before, this was done only in memory because logging a new name doesn't imply syncing the log. This led to some surprises in scenarios such as the following: 1) write some extents to an inode; 2) fsync the inode; 3) truncate the inode or delete/modify some of its xattrs 4) add a new hard link for that inode 5) fsync some other file, to force the log tree to be durably persisted 6) power failure happens The next time the fs is mounted, the fsync log replay code is executed, and the resulting file doesn't have the content it had when the last fsync against it was performed, instead if has a content matching what it had when the last transaction commit happened. So change the behaviour such that when a new name is logged, only the inode item and reference items are processed. This is easy to reproduce with the test I just made for xfstests, whose main body is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Now shrink our file to 5000 bytes. $XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo # Now do an expanding truncate to a size larger than what we had when we last # fsync'ed our file. This is just to verify that after power failure and # replaying the fsync log, our file matches what it was when we last fsync'ed # it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of # data had a value of 0xcc. $XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs drop all of our file's # metadata from the fsync log, including the metadata relative to the # extent we just wrote and fsync'ed. This change was made only to the fsync # log in memory, so adding the hard link alone doesn't change the persisted # fsync log. This happened because the previous truncates set the runtime # flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. # After this our persisted fsync log will no longer have metadata for our file # foo that points to the extent we wrote and fsync'ed before. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to see a file # with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all # the remaining bytes with value 0x00. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The expected result is to see a file with a size of 12Kb, with its first 8Kb # of data having the value 0xaa and its last 4Kb of data having a value of 0xcc. # The btrfs bug used to leave the file as it used te be as of the last # transaction commit - that is, with a size of 8Kb with all bytes having a # value of 0xaa. echo "File content after:" od -t x1 $SCRATCH_MNT/foo The test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 16:56:14 +00:00
}
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
} else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags) ||
inode_only == LOG_INODE_EXISTS) {
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
if (inode_only == LOG_INODE_ALL)
fast_search = true;
Btrfs: remove deleted xattrs on fsync log replay If we deleted xattrs from a file and fsynced the file, after a log replay the xattrs would remain associated to the file. This was an unexpected behaviour and differs from what other filesystems do, such as for example xfs and ext3/4. Fix this by, on fsync log replay, check if every xattr in the fs/subvol tree (that belongs to a logged inode) has a matching xattr in the log, and if it does not, delete it from the fs/subvol tree. This is a similar approach to what we do for dentries when we replay a directory from the fsync log. This issue is trivial to reproduce, and the following excerpt from my test for xfstests triggers the issue: _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create out test file and add 3 xattrs to it. touch $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr1 -v val1 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr2 -v val2 $SCRATCH_MNT/foobar $SETFATTR_PROG -n user.attr3 -v val3 $SCRATCH_MNT/foobar # Make sure everything is durably persisted. sync # Now delete the second xattr and fsync the inode. $SETFATTR_PROG -x user.attr2 $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar _crash_and_mount # After the fsync log is replayed, the file should have only 2 xattrs, the ones # named user.attr1 and user.attr3. The btrfs fsync log replay bug left the file # with the 3 xattrs that we had before deleting the second one and fsyncing the # file. echo "xattr names and values after first fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch # Now write some data to our file, fsync it, remove the first xattr, add a new # hard link to our file and commit the fsync log by fsyncing some other new # file. This is to verify that after log replay our first xattr does not exist # anymore. echo "hello world!" >> $SCRATCH_MNT/foobar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar $SETFATTR_PROG -x user.attr1 $SCRATCH_MNT/foobar ln $SCRATCH_MNT/foobar $SCRATCH_MNT/foobar_link touch $SCRATCH_MNT/qwerty $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/qwerty _crash_and_mount # Now only the xattr with name user.attr3 should be set in our file. echo "xattr names and values after second fsync log replay:" $GETFATTR_PROG --absolute-names --dump $SCRATCH_MNT/foobar | _filter_scratch status=0 exit The expected golden output, which is produced with this patch applied or when testing against xfs or ext3/4, is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr3="val3" Without this patch applied, the output is: xattr names and values after first fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" xattr names and values after second fsync log replay: # file: SCRATCH_MNT/foobar user.attr1="val1" user.attr2="val2" user.attr3="val3" A patch with a test case for xfstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-23 19:53:35 +00:00
max_key.type = BTRFS_XATTR_ITEM_KEY;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
ret = drop_objectid_items(trans, log, path, ino,
max_key.type);
} else {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
goto log_extents;
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
}
}
if (ret) {
err = ret;
goto out_unlock;
}
while (1) {
ins_nr = 0;
ret = btrfs_search_forward(root, &min_key,
path, trans->transid);
if (ret < 0) {
err = ret;
goto out_unlock;
}
if (ret != 0)
break;
again:
/* note, ins_nr might be > 0 here, cleanup outside the loop */
if (min_key.objectid != ino)
break;
if (min_key.type > max_key.type)
break;
Btrfs: fix fsync data loss after append write If we do an append write to a file (which increases its inode's i_size) that does not have the flag BTRFS_INODE_NEEDS_FULL_SYNC set in its inode, and the previous transaction added a new hard link to the file, which sets the flag BTRFS_INODE_COPY_EVERYTHING in the file's inode, and then fsync the file, the inode's new i_size isn't logged. This has the consequence that after the fsync log is replayed, the file size remains what it was before the append write operation, which means users/applications will not be able to read the data that was successsfully fsync'ed before. This happens because neither the inode item nor the delayed inode get their i_size updated when the append write is made - doing so would require starting a transaction in the buffered write path, something that we do not do intentionally for performance reasons. Fix this by making sure that when the flag BTRFS_INODE_COPY_EVERYTHING is set the inode is logged with its current i_size (log the in-memory inode into the log tree). This issue is not a recent regression and is easy to reproduce with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs generic _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and then fsync it. # The fsync here is only needed to trigger the issue in btrfs, as it causes the # the flag BTRFS_INODE_NEEDS_FULL_SYNC to be removed from the btrfs inode. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io sync # Add a hard link to our file. # On btrfs this sets the flag BTRFS_INODE_COPY_EVERYTHING on the btrfs inode, # which is a necessary condition to trigger the issue. ln $SCRATCH_MNT/foo $SCRATCH_MNT/bar # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now append more data to our file, increasing its size, and fsync the file. # In btrfs because the inode flag BTRFS_INODE_COPY_EVERYTHING was set and the # write path did not update the inode item in the btree nor the delayed inode # item (in memory struture) in the current transaction (created by the fsync # handler), the fsync did not record the inode's new i_size in the fsync # log/journal. This made the data unavailable after the fsync log/journal is # replayed. $XFS_IO_PROG -c "pwrite -S 0xbb 32K 32K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io echo "File content after fsync and before crash:" od -t x1 $SCRATCH_MNT/foo _crash_and_mount echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo status=0 exit The expected file output before and after the crash/power failure expects the appended data to be available, which is: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0100000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0200000 Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-17 11:49:23 +00:00
if (min_key.type == BTRFS_INODE_ITEM_KEY)
need_log_inode_item = false;
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
if ((min_key.type == BTRFS_INODE_REF_KEY ||
min_key.type == BTRFS_INODE_EXTREF_KEY) &&
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
inode->generation == trans->transid &&
!recursive_logging) {
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
u64 other_ino = 0;
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
u64 other_parent = 0;
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
ret = btrfs_check_ref_name_override(path->nodes[0],
path->slots[0], &min_key, inode,
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
&other_ino, &other_parent);
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
if (ret < 0) {
err = ret;
goto out_unlock;
Btrfs: fix lockdep warning on deadlock against an inode's log mutex Commit 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink"), which landed in 4.8-rc2, introduced a possibility for a deadlock due to double locking of an inode's log mutex by the same task, which lockdep reports with: [23045.433975] ============================================= [23045.434748] [ INFO: possible recursive locking detected ] [23045.435426] 4.7.0-rc6-btrfs-next-34+ #1 Not tainted [23045.436044] --------------------------------------------- [23045.436044] xfs_io/3688 is trying to acquire lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] but task is already holding lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] other info that might help us debug this: [23045.436044] Possible unsafe locking scenario: [23045.436044] CPU0 [23045.436044] ---- [23045.436044] lock(&ei->log_mutex); [23045.436044] lock(&ei->log_mutex); [23045.436044] *** DEADLOCK *** [23045.436044] May be due to missing lock nesting notation [23045.436044] 3 locks held by xfs_io/3688: [23045.436044] #0: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffffa035f2ae>] btrfs_sync_file+0x14e/0x425 [btrfs] [23045.436044] #1: (sb_internal#2){.+.+.+}, at: [<ffffffff8118446b>] __sb_start_write+0x5f/0xb0 [23045.436044] #2: (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] stack backtrace: [23045.436044] CPU: 4 PID: 3688 Comm: xfs_io Not tainted 4.7.0-rc6-btrfs-next-34+ #1 [23045.436044] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [23045.436044] 0000000000000000 ffff88022f5f7860 ffffffff8127074d ffffffff82a54b70 [23045.436044] ffffffff82a54b70 ffff88022f5f7920 ffffffff81092897 ffff880228015d68 [23045.436044] 0000000000000000 ffffffff82a54b70 ffffffff829c3f00 ffff880228015d68 [23045.436044] Call Trace: [23045.436044] [<ffffffff8127074d>] dump_stack+0x67/0x90 [23045.436044] [<ffffffff81092897>] __lock_acquire+0xcbb/0xe4e [23045.436044] [<ffffffff8109155f>] ? mark_lock+0x24/0x201 [23045.436044] [<ffffffff8109179a>] ? mark_held_locks+0x5e/0x74 [23045.436044] [<ffffffff81092de0>] lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffff81092de0>] ? lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff814a51a4>] mutex_lock_nested+0x77/0x3a7 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa039705e>] ? btrfs_release_delayed_node+0xb/0xd [btrfs] [23045.436044] [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff810a0ed1>] ? vprintk_emit+0x453/0x465 [23045.436044] [<ffffffffa0385a61>] btrfs_log_inode+0x66e/0xc95 [btrfs] [23045.436044] [<ffffffffa03c084d>] log_new_dir_dentries+0x26c/0x359 [btrfs] [23045.436044] [<ffffffffa03865aa>] btrfs_log_inode_parent+0x4a6/0x628 [btrfs] [23045.436044] [<ffffffffa0387552>] btrfs_log_dentry_safe+0x5a/0x75 [btrfs] [23045.436044] [<ffffffffa035f464>] btrfs_sync_file+0x304/0x425 [btrfs] [23045.436044] [<ffffffff811acaf4>] vfs_fsync_range+0x8c/0x9e [23045.436044] [<ffffffff811acb22>] vfs_fsync+0x1c/0x1e [23045.436044] [<ffffffff811acc79>] do_fsync+0x31/0x4a [23045.436044] [<ffffffff811ace99>] SyS_fsync+0x10/0x14 [23045.436044] [<ffffffff814a88e5>] entry_SYSCALL_64_fastpath+0x18/0xa8 [23045.436044] [<ffffffff8108f039>] ? trace_hardirqs_off_caller+0x3f/0xaa An example reproducer for this is: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ sync $ mv /mnt/dir/foo /mnt/dir/bar $ touch /mnt/dir/foo $ xfs_io -c "fsync" /mnt/dir/bar This is because while logging the inode of file bar we end up logging its parent directory (since its inode has an unlink_trans field matching the current transaction id due to the rename operation), which in turn logs the inodes for all its new dentries, so that the new inode for the new file named foo gets logged which in turn triggered another logging attempt for the inode we are fsync'ing, since that inode had an old name that corresponds to the name of the new inode. So fix this by ensuring that when logging the inode for a new dentry that has a name matching an old name of some other inode, we don't log again the original inode that we are fsync'ing. Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-23 20:13:51 +00:00
} else if (ret > 0 && ctx &&
other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
if (ins_nr > 0) {
ins_nr++;
} else {
ins_nr = 1;
ins_start_slot = path->slots[0];
}
ret = copy_items(trans, inode, dst_path, path,
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
&last_extent, ins_start_slot,
ins_nr, inode_only,
logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ins_nr = 0;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
err = log_conflicting_inodes(trans, root, path,
Btrfs: fix fsync after succession of renames and unlink/rmdir After a succession of renames operations of different files and unlinking one of them, if we fsync one of the renamed files we can end up with a log that will either fail to replay at mount time or result in a filesystem that is in an inconsistent state. One example scenario: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ rm -f /mnt/testdir/fname2 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt $ umount /mnt $ btrfs check /dev/sdb [1/7] checking root items [2/7] checking extents [3/7] checking free space cache [4/7] checking fs roots root 5 inode 259 errors 2, no orphan item ERROR: errors found in fs roots Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d found 393216 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 122986 file data blocks allocated: 262144 referenced 262144 On a kernel without the first patch in this series, titled "[PATCH] Btrfs: fix fsync after succession of renames of different files", we get instead an error when mounting the filesystem due to failure of replaying the log: $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists Fix this by logging the parent directory of an inode whenever we find an inode that no longer exists (was unlinked in the current transaction), during the procedure which finds inodes that have old names that collide with new names of other inodes. A test case for fstests follows soon. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:09 +00:00
ctx, other_ino, other_parent);
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
if (err)
goto out_unlock;
Btrfs: fix fsync after succession of renames of different files After a succession of rename operations of different files and fsyncing one of them, such that each file gets a new name that corresponds to an old name of another file, we can end up with a log that will cause a failure when attempted to replay at mount time (an EEXIST error). We currently have correct behaviour when such succession of renames involves only two files, but if there are more files involved, we end up not logging all the inodes that are needed, therefore resulting in a failure when attempting to replay the log. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/fname1 $ touch /mnt/testdir/fname2 $ sync $ mv /mnt/testdir/fname1 /mnt/testdir/fname3 $ mv /mnt/testdir/fname2 /mnt/testdir/fname4 $ ln /mnt/testdir/fname3 /mnt/testdir/fname2 $ touch /mnt/testdir/fname1 $ xfs_io -c "fsync" /mnt/testdir/fname1 <power failure> $ mount /dev/sdb /mnt mount: mount /dev/sdb on /mnt failed: File exists So fix this by checking all inode dependencies when logging an inode. That is, if one logged inode A has a new name that matches the old name of some other inode B, check if inode B has a new name that matches the old name of some other inode C, and so on. This fix is implemented not by doing any recursive function calls but by using an iterative method using a linked list that is used in a first-in-first-out fashion. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-13 12:14:03 +00:00
btrfs_release_path(path);
goto next_key;
Btrfs: fix file/data loss caused by fsync after rename and new inode If we rename an inode A (be it a file or a directory), create a new inode B with the old name of inode A and under the same parent directory, fsync inode B and then power fail, at log tree replay time we end up removing inode A completely. If inode A is a directory then all its files are gone too. Example scenarios where this happens: This is reproducible with the following steps, taken from a couple of test cases written for fstests which are going to be submitted upstream soon: # Scenario 1 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir -p /mnt/a/x echo "hello" > /mnt/a/x/foo echo "world" > /mnt/a/x/bar sync mv /mnt/a/x /mnt/a/y mkdir /mnt/a/x xfs_io -c fsync /mnt/a/x <power failure happens> The next time the fs is mounted, log tree replay happens and the directory "y" does not exist nor do the files "foo" and "bar" exist anywhere (neither in "y" nor in "x", nor the root nor anywhere). # Scenario 2 mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/a echo "hello" > /mnt/a/foo sync mv /mnt/a/foo /mnt/a/bar echo "world" > /mnt/a/foo xfs_io -c fsync /mnt/a/foo <power failure happens> The next time the fs is mounted, log tree replay happens and the file "bar" does not exists anymore. A file with the name "foo" exists and it matches the second file we created. Another related problem that does not involve file/data loss is when a new inode is created with the name of a deleted snapshot and we fsync it: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt mkdir /mnt/testdir btrfs subvolume snapshot /mnt /mnt/testdir/snap btrfs subvolume delete /mnt/testdir/snap rmdir /mnt/testdir mkdir /mnt/testdir xfs_io -c fsync /mnt/testdir # or fsync some file inside /mnt/testdir <power failure> The next time the fs is mounted the log replay procedure fails because it attempts to delete the snapshot entry (which has dir item key type of BTRFS_ROOT_ITEM_KEY) as if it were a regular (non-root) entry, resulting in the following error that causes mount to fail: [52174.510532] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [52174.512570] ------------[ cut here ]------------ [52174.513278] WARNING: CPU: 12 PID: 28024 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x178/0x351 [btrfs]() [52174.514681] BTRFS: Transaction aborted (error -2) [52174.515630] Modules linked in: btrfs dm_flakey dm_mod overlay crc32c_generic ppdev xor raid6_pq acpi_cpufreq parport_pc tpm_tis sg parport tpm evdev i2c_piix4 proc [52174.521568] CPU: 12 PID: 28024 Comm: mount Tainted: G W 4.5.0-rc6-btrfs-next-27+ #1 [52174.522805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [52174.524053] 0000000000000000 ffff8801df2a7710 ffffffff81264e93 ffff8801df2a7758 [52174.524053] 0000000000000009 ffff8801df2a7748 ffffffff81051618 ffffffffa03591cd [52174.524053] 00000000fffffffe ffff88015e6e5000 ffff88016dbc3c88 ffff88016dbc3c88 [52174.524053] Call Trace: [52174.524053] [<ffffffff81264e93>] dump_stack+0x67/0x90 [52174.524053] [<ffffffff81051618>] warn_slowpath_common+0x99/0xb2 [52174.524053] [<ffffffffa03591cd>] ? __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff81051679>] warn_slowpath_fmt+0x48/0x50 [52174.524053] [<ffffffffa03591cd>] __btrfs_unlink_inode+0x178/0x351 [btrfs] [52174.524053] [<ffffffff8118f5e9>] ? iput+0xb0/0x284 [52174.524053] [<ffffffffa0359fe8>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [52174.524053] [<ffffffffa038631e>] check_item_in_log+0x1fe/0x29b [btrfs] [52174.524053] [<ffffffffa0386522>] replay_dir_deletes+0x167/0x1cf [btrfs] [52174.524053] [<ffffffffa038739e>] fixup_inode_link_count+0x289/0x2aa [btrfs] [52174.524053] [<ffffffffa038748a>] fixup_inode_link_counts+0xcb/0x105 [btrfs] [52174.524053] [<ffffffffa038a5ec>] btrfs_recover_log_trees+0x258/0x32c [btrfs] [52174.524053] [<ffffffffa03885b2>] ? replay_one_extent+0x511/0x511 [btrfs] [52174.524053] [<ffffffffa034f288>] open_ctree+0x1dd4/0x21b9 [btrfs] [52174.524053] [<ffffffffa032b753>] btrfs_mount+0x97e/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffffa032af81>] btrfs_mount+0x1ac/0xaed [btrfs] [52174.524053] [<ffffffff8108e1b7>] ? trace_hardirqs_on+0xd/0xf [52174.524053] [<ffffffff8108c262>] ? lockdep_init_map+0xb9/0x1b3 [52174.524053] [<ffffffff8117bafa>] mount_fs+0x67/0x131 [52174.524053] [<ffffffff81193003>] vfs_kern_mount+0x6c/0xde [52174.524053] [<ffffffff8119590f>] do_mount+0x8a6/0x9e8 [52174.524053] [<ffffffff811358dd>] ? strndup_user+0x3f/0x59 [52174.524053] [<ffffffff81195c65>] SyS_mount+0x77/0x9f [52174.524053] [<ffffffff814935d7>] entry_SYSCALL_64_fastpath+0x12/0x6b [52174.561288] ---[ end trace 6b53049efb1a3ea6 ]--- Fix this by forcing a transaction commit when such cases happen. This means we check in the commit root of the subvolume tree if there was any other inode with the same reference when the inode we are fsync'ing is a new inode (created in the current transaction). Test cases for fstests, covering all the scenarios given above, were submitted upstream for fstests: * fstests: generic test for fsync after renaming directory https://patchwork.kernel.org/patch/8694281/ * fstests: generic test for fsync after renaming file https://patchwork.kernel.org/patch/8694301/ * fstests: add btrfs test for fsync after snapshot deletion https://patchwork.kernel.org/patch/8670671/ Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-03-30 22:37:21 +00:00
}
}
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
/* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
if (min_key.type == BTRFS_XATTR_ITEM_KEY) {
if (ins_nr == 0)
goto next_slot;
ret = copy_items(trans, inode, dst_path, path,
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
&last_extent, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ins_nr = 0;
if (ret) {
btrfs_release_path(path);
continue;
}
goto next_slot;
}
if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
ins_nr++;
goto next_slot;
} else if (!ins_nr) {
ins_start_slot = path->slots[0];
ins_nr = 1;
goto next_slot;
}
ret = copy_items(trans, inode, dst_path, path, &last_extent,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
ins_start_slot, ins_nr, inode_only,
logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
if (ret) {
ins_nr = 0;
btrfs_release_path(path);
continue;
}
ins_nr = 1;
ins_start_slot = path->slots[0];
next_slot:
nritems = btrfs_header_nritems(path->nodes[0]);
path->slots[0]++;
if (path->slots[0] < nritems) {
btrfs_item_key_to_cpu(path->nodes[0], &min_key,
path->slots[0]);
goto again;
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path,
&last_extent, ins_start_slot,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
ins_nr, inode_only, logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ret = 0;
ins_nr = 0;
}
btrfs_release_path(path);
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
next_key:
if (min_key.offset < (u64)-1) {
min_key.offset++;
} else if (min_key.type < max_key.type) {
min_key.type++;
min_key.offset = 0;
} else {
break;
}
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path, &last_extent,
Btrfs: fix fsync data loss after adding hard link to inode We have a scenario where after the fsync log replay we can lose file data that had been previously fsync'ed if we added an hard link for our inode and after that we sync'ed the fsync log (for example by fsync'ing some other file or directory). This is because when adding an hard link we updated the inode item in the log tree with an i_size value of 0. At that point the new inode item was in memory only and a subsequent fsync log replay would not make us lose the file data. However if after adding the hard link we sync the log tree to disk, by fsync'ing some other file or directory for example, we ended up losing the file data after log replay, because the inode item in the persisted log tree had an an i_size of zero. This is easy to reproduce, and the following excerpt from my test for xfstests shows this: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create one file with data and fsync it. # This made the btrfs fsync log persist the data and the inode metadata with # a correct inode->i_size (4096 bytes). $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now add one hard link to our file. This made the btrfs code update the fsync # log, in memory only, with an inode metadata having a size of 0. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now force persistence of the fsync log to disk, for example, by fsyncing some # other file. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # Before a power loss or crash, we could read the 4Kb of data from our file as # expected. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the fsync log replay, because the fsync log had a value of 0 for our # inode's i_size, we couldn't read anymore the 4Kb of data that we previously # wrote and fsync'ed. The size of the file became 0 after the fsync log replay. echo "File content after:" od -t x1 $SCRATCH_MNT/foo Another alternative test, that doesn't need to fsync an inode in the same transaction it was created, is: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with some data. $XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Make sure the file is durably persisted. sync # Append some data to our file, to increase its size. $XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Fsync the file, so from this point on if a crash/power failure happens, our # new data is guaranteed to be there next time the fs is mounted. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Add one hard link to our file. This made btrfs write into the in memory fsync # log a special inode with generation 0 and an i_size of 0 too. Note that this # didn't update the inode in the fsync log on disk. ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link # Now make sure the in memory fsync log is durably persisted. # Creating and fsync'ing another file will do it. touch $SCRATCH_MNT/bar $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar # As expected, before the crash/power failure, we should be able to read the # 12Kb of file data. echo "File content before:" od -t x1 $SCRATCH_MNT/foo # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After mounting the fs again, the fsync log was replayed. # The btrfs fsync log replay code didn't update the i_size of the persisted # inode because the inode item in the log had a special generation with a # value of 0 (and it couldn't know the correct i_size, since that inode item # had a 0 i_size too). This made the last 4Kb of file data inaccessible and # effectively lost. echo "File content after:" od -t x1 $SCRATCH_MNT/foo This isn't a new issue/regression. This problem has been around since the log tree code was added in 2008: Btrfs: Add a write ahead tree log to optimize synchronous operations (commit e02119d5a7b4396c5a872582fddc8bd6d305a70a) Test cases for xfstests follow soon. CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-02-13 12:30:56 +00:00
ins_start_slot, ins_nr, inode_only,
logged_isize);
if (ret < 0) {
err = ret;
goto out_unlock;
}
ret = 0;
ins_nr = 0;
}
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
btrfs_release_path(path);
btrfs_release_path(dst_path);
err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path);
Btrfs: fix fsync xattr loss in the fast fsync path After commit 4f764e515361 ("Btrfs: remove deleted xattrs on fsync log replay"), we can end up in a situation where during log replay we end up deleting xattrs that were never deleted when their file was last fsynced. This happens in the fast fsync path (flag BTRFS_INODE_NEEDS_FULL_SYNC is not set in the inode) if the inode has the flag BTRFS_INODE_COPY_EVERYTHING set, the xattr was added in a past transaction and the leaf where the xattr is located was not updated (COWed or created) in the current transaction. In this scenario the xattr item never ends up in the log tree and therefore at log replay time, which makes the replay code delete the xattr from the fs/subvol tree as it thinks that xattr was deleted prior to the last fsync. Fix this by always logging all xattrs, which is the simplest and most reliable way to detect deleted xattrs and replay the deletes at log replay time. This issue is reproducible with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey . ./common/attr # real QA test starts here # We create a lot of xattrs for a single file. Only btrfs and xfs are currently # able to store such a large mount of xattrs per file, other filesystems such # as ext3/4 and f2fs for example, fail with ENOSPC even if we attempt to add # less than 1000 xattrs with very small values. _supported_fs btrfs xfs _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_attrs _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and make sure everything is # durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" $SCRATCH_MNT/foo | _filter_xfs_io sync # Add many small xattrs to our file. # We create such a large amount because it's needed to trigger the issue found # in btrfs - we need to have an amount that causes the fs to have at least 3 # btree leafs with xattrs stored in them, and it must work on any leaf size # (maximum leaf/node size is 64Kb). num_xattrs=2000 for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" $SETFATTR_PROG -n $name -v "val_$(printf "%04d" $i)" $SCRATCH_MNT/foo done # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now update our file's data and fsync the file. # After a successful fsync, if the fsync log/journal is replayed we expect to # see all the xattrs we added before with the same values (and the updated file # data of course). Btrfs used to delete some of these xattrs when it replayed # its fsync log/journal. $XFS_IO_PROG -c "pwrite -S 0xbb 8K 16K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo echo "File xattrs after crash and log replay:" for ((i = 1; i <= $num_xattrs; i++)); do name="user.attr_$(printf "%04d" $i)" echo -n "$name=" $GETFATTR_PROG --absolute-names -n $name --only-values $SCRATCH_MNT/foo echo done status=0 exit The golden output expects all xattrs to be available, and with the correct values, after the fsync log is replayed. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-19 23:44:51 +00:00
if (err)
goto out_unlock;
xattrs_logged = true;
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
btrfs_release_path(path);
btrfs_release_path(dst_path);
err = btrfs_log_trailing_hole(trans, root, inode, path);
Btrfs: fix fsync after truncate when no_holes feature is enabled When we have the no_holes feature enabled, if a we truncate a file to a smaller size, truncate it again but to a size greater than or equals to its original size and fsync it, the log tree will not have any information about the hole covering the range [truncate_1_offset, new_file_size[. Which means if the fsync log is replayed, the file will remain with the state it had before both truncate operations. Without the no_holes feature this does not happen, since when the inode is logged (full sync flag is set) it will find in the fs/subvol tree a leaf with a generation matching the current transaction id that has an explicit extent item representing the hole. Fix this by adding an explicit extent item representing a hole between the last extent and the inode's i_size if we are doing a full sync. The issue is easy to reproduce with the following test case for fstests: . ./common/rc . ./common/filter . ./common/dmflakey _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey # This test was motivated by an issue found in btrfs when the btrfs # no-holes feature is enabled (introduced in kernel 3.14). So enable # the feature if the fs being tested is btrfs. if [ $FSTYP == "btrfs" ]; then _require_btrfs_fs_feature "no_holes" _require_btrfs_mkfs_feature "no-holes" MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes" fi rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test files and make sure everything is durably persisted. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" \ -c "pwrite -S 0xbb 64K 61K" \ $SCRATCH_MNT/foo | _filter_xfs_io $XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K" \ -c "pwrite -S 0xff 64K 61K" \ $SCRATCH_MNT/bar | _filter_xfs_io sync # Now truncate our file foo to a smaller size (64Kb) and then truncate # it to the size it had before the shrinking truncate (125Kb). Then # fsync our file. If a power failure happens after the fsync, we expect # our file to have a size of 125Kb, with the first 64Kb of data having # the value 0xaa and the second 61Kb of data having the value 0x00. $XFS_IO_PROG -c "truncate 64K" \ -c "truncate 125K" \ -c "fsync" \ $SCRATCH_MNT/foo # Do something similar to our file bar, but the first truncation sets # the file size to 0 and the second truncation expands the size to the # double of what it was initially. $XFS_IO_PROG -c "truncate 0" \ -c "truncate 253K" \ -c "fsync" \ $SCRATCH_MNT/bar _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # We expect foo to have a size of 125Kb, the first 64Kb of data all # having the value 0xaa and the remaining 61Kb to be a hole (all bytes # with value 0x00). echo "File foo content after log replay:" od -t x1 $SCRATCH_MNT/foo # We expect bar to have a size of 253Kb and no extents (any byte read # from bar has the value 0x00). echo "File bar content after log replay:" od -t x1 $SCRATCH_MNT/bar status=0 exit The expected file contents in the golden output are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0372000 File bar content after log replay: 0000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 Without this fix, their contents are: File foo content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0372000 File bar content after log replay: 0000000 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee * 0200000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0372000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0772000 A test case submission for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-25 03:17:46 +00:00
if (err)
goto out_unlock;
}
log_extents:
btrfs_release_path(path);
btrfs_release_path(dst_path);
Btrfs: fix fsync data loss after append write If we do an append write to a file (which increases its inode's i_size) that does not have the flag BTRFS_INODE_NEEDS_FULL_SYNC set in its inode, and the previous transaction added a new hard link to the file, which sets the flag BTRFS_INODE_COPY_EVERYTHING in the file's inode, and then fsync the file, the inode's new i_size isn't logged. This has the consequence that after the fsync log is replayed, the file size remains what it was before the append write operation, which means users/applications will not be able to read the data that was successsfully fsync'ed before. This happens because neither the inode item nor the delayed inode get their i_size updated when the append write is made - doing so would require starting a transaction in the buffered write path, something that we do not do intentionally for performance reasons. Fix this by making sure that when the flag BTRFS_INODE_COPY_EVERYTHING is set the inode is logged with its current i_size (log the in-memory inode into the log tree). This issue is not a recent regression and is easy to reproduce with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs generic _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and then fsync it. # The fsync here is only needed to trigger the issue in btrfs, as it causes the # the flag BTRFS_INODE_NEEDS_FULL_SYNC to be removed from the btrfs inode. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io sync # Add a hard link to our file. # On btrfs this sets the flag BTRFS_INODE_COPY_EVERYTHING on the btrfs inode, # which is a necessary condition to trigger the issue. ln $SCRATCH_MNT/foo $SCRATCH_MNT/bar # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now append more data to our file, increasing its size, and fsync the file. # In btrfs because the inode flag BTRFS_INODE_COPY_EVERYTHING was set and the # write path did not update the inode item in the btree nor the delayed inode # item (in memory struture) in the current transaction (created by the fsync # handler), the fsync did not record the inode's new i_size in the fsync # log/journal. This made the data unavailable after the fsync log/journal is # replayed. $XFS_IO_PROG -c "pwrite -S 0xbb 32K 32K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io echo "File content after fsync and before crash:" od -t x1 $SCRATCH_MNT/foo _crash_and_mount echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo status=0 exit The expected file output before and after the crash/power failure expects the appended data to be available, which is: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0100000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0200000 Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-17 11:49:23 +00:00
if (need_log_inode_item) {
err = log_inode_item(trans, log, dst_path, inode);
if (!err && !xattrs_logged) {
err = btrfs_log_all_xattrs(trans, root, inode, path,
dst_path);
btrfs_release_path(path);
}
Btrfs: fix fsync data loss after append write If we do an append write to a file (which increases its inode's i_size) that does not have the flag BTRFS_INODE_NEEDS_FULL_SYNC set in its inode, and the previous transaction added a new hard link to the file, which sets the flag BTRFS_INODE_COPY_EVERYTHING in the file's inode, and then fsync the file, the inode's new i_size isn't logged. This has the consequence that after the fsync log is replayed, the file size remains what it was before the append write operation, which means users/applications will not be able to read the data that was successsfully fsync'ed before. This happens because neither the inode item nor the delayed inode get their i_size updated when the append write is made - doing so would require starting a transaction in the buffered write path, something that we do not do intentionally for performance reasons. Fix this by making sure that when the flag BTRFS_INODE_COPY_EVERYTHING is set the inode is logged with its current i_size (log the in-memory inode into the log tree). This issue is not a recent regression and is easy to reproduce with the following test case for fstests: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! _cleanup() { _cleanup_flakey rm -f $tmp.* } trap "_cleanup; exit \$status" 0 1 2 3 15 # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _supported_fs generic _supported_os Linux _need_to_be_root _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV _crash_and_mount() { # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again and mount. This makes the fs replay its fsync log. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey } rm -f $seqres.full _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create the test file with some initial data and then fsync it. # The fsync here is only needed to trigger the issue in btrfs, as it causes the # the flag BTRFS_INODE_NEEDS_FULL_SYNC to be removed from the btrfs inode. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 32k" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io sync # Add a hard link to our file. # On btrfs this sets the flag BTRFS_INODE_COPY_EVERYTHING on the btrfs inode, # which is a necessary condition to trigger the issue. ln $SCRATCH_MNT/foo $SCRATCH_MNT/bar # Sync the filesystem to force a commit of the current btrfs transaction, this # is a necessary condition to trigger the bug on btrfs. sync # Now append more data to our file, increasing its size, and fsync the file. # In btrfs because the inode flag BTRFS_INODE_COPY_EVERYTHING was set and the # write path did not update the inode item in the btree nor the delayed inode # item (in memory struture) in the current transaction (created by the fsync # handler), the fsync did not record the inode's new i_size in the fsync # log/journal. This made the data unavailable after the fsync log/journal is # replayed. $XFS_IO_PROG -c "pwrite -S 0xbb 32K 32K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io echo "File content after fsync and before crash:" od -t x1 $SCRATCH_MNT/foo _crash_and_mount echo "File content after crash and log replay:" od -t x1 $SCRATCH_MNT/foo status=0 exit The expected file output before and after the crash/power failure expects the appended data to be available, which is: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0100000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb * 0200000 Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-17 11:49:23 +00:00
if (err)
goto out_unlock;
}
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
if (fast_search) {
ret = btrfs_log_changed_extents(trans, root, inode, dst_path,
ctx, start, end);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
if (ret) {
err = ret;
goto out_unlock;
}
} else if (inode_only == LOG_INODE_ALL) {
struct extent_map *em, *n;
write_lock(&em_tree->lock);
/*
* We can't just remove every em if we're called for a ranged
* fsync - that is, one that doesn't cover the whole possible
* file range (0 to LLONG_MAX). This is because we can have
* em's that fall outside the range we're logging and therefore
* their ordered operations haven't completed yet
* (btrfs_finish_ordered_io() not invoked yet). This means we
* didn't get their respective file extent item in the fs/subvol
* tree yet, and need to let the next fast fsync (one which
* consults the list of modified extent maps) find the em so
* that it logs a matching file extent item and waits for the
* respective ordered operation to complete (if it's still
* running).
*
* Removing every em outside the range we're logging would make
* the next fast fsync not log their matching file extent items,
* therefore making us lose data after a log replay.
*/
list_for_each_entry_safe(em, n, &em_tree->modified_extents,
list) {
const u64 mod_end = em->mod_start + em->mod_len - 1;
if (em->mod_start >= start && mod_end <= end)
list_del_init(&em->list);
}
write_unlock(&em_tree->lock);
Btrfs: turbo charge fsync At least for the vm workload. Currently on fsync we will 1) Truncate all items in the log tree for the given inode if they exist and 2) Copy all items for a given inode into the log The problem with this is that for things like VMs you can have lots of extents from the fragmented writing behavior, and worst yet you may have only modified a few extents, not the entire thing. This patch fixes this problem by tracking which transid modified our extent, and then when we do the tree logging we find all of the extents we've modified in our current transaction, sort them and commit them. We also only truncate up to the xattrs of the inode and copy that stuff in normally, and then just drop any extents in the range we have that exist in the log already. Here are some numbers of a 50 meg fio job that does random writes and fsync()s after every write Original Patched SATA drive 82KB/s 140KB/s Fusion drive 431KB/s 2532KB/s So around 2-6 times faster depending on your hardware. There are a few corner cases, for example if you truncate at all we have to do it the old way since there is no way to be sure what is in the log is ok. This probably could be done smarter, but if you write-fsync-truncate-write-fsync you deserve what you get. All this work is in RAM of course so if your inode gets evicted from cache and you read it in and fsync it we'll do it the slow way if we are still in the same transaction that we last modified the inode in. The biggest cool part of this is that it requires no changes to the recovery code, so if you fsync with this patch and crash and load an old kernel, it will run the recovery and be a-ok. I have tested this pretty thoroughly with an fsync tester and everything comes back fine, as well as xfstests. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-08-17 17:14:17 +00:00
}
if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) {
ret = log_directory_changes(trans, root, inode, path, dst_path,
ctx);
if (ret) {
err = ret;
goto out_unlock;
}
}
Btrfs: fix data loss after inode eviction, renaming it, and fsync it When we log an inode, regardless of logging it completely or only that it exists, we always update it as logged (logged_trans and last_log_commit fields of the inode are updated). This is generally fine and avoids future attempts to log it from having to do repeated work that brings no value. However, if we write data to a file, then evict its inode after all the dealloc was flushed (and ordered extents completed), rename the file and fsync it, we end up not logging the new extents, since the rename may result in logging that the inode exists in case the parent directory was logged before. The following reproducer shows and explains how this can happen: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ touch /mnt/dir/bar # Do a direct IO write instead of a buffered write because with a # buffered write we would need to make sure dealloc gets flushed and # complete before we do the inode eviction later, and we can not do that # from user space with call to things such as sync(2) since that results # in a transaction commit as well. $ xfs_io -d -c "pwrite -S 0xd3 0 4K" /mnt/dir/bar # Keep the directory dir in use while we evict inodes. We want our file # bar's inode to be evicted but we don't want our directory's inode to # be evicted (if it were evicted too, we would not be able to reproduce # the issue since the first fsync below, of file foo, would result in a # transaction commit. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time for the background process to chdir. $ sleep 0.1 # Evict all inodes, except the inode for the directory dir because it is # currently in use by our background process. $ echo 2 > /proc/sys/vm/drop_caches # fsync file foo, which ends up persisting information about the parent # directory because it is a new inode. $ xfs_io -c fsync /mnt/dir/foo # Rename bar, this results in logging that this inode exists (inode item, # names, xattrs) because the parent directory is in the log. $ mv /mnt/dir/bar /mnt/dir/baz # Now fsync baz, which ends up doing absolutely nothing because of the # rename operation which logged that the inode exists only. $ xfs_io -c fsync /mnt/dir/baz <power failure> $ mount /dev/sdb /mnt $ od -t x1 -A d /mnt/dir/baz 0000000 --> Empty file, data we wrote is missing. Fix this by not updating last_sub_trans of an inode when we are logging only that it exists and the inode was not yet logged since it was loaded from disk (full_sync bit set), this is enough to make btrfs_inode_in_log() return false for this scenario and make us log the inode. The logged_trans of the inode is still always setsince that alone is used to track if names need to be deleted as part of unlink operations. Fixes: 257c62e1bce03e ("Btrfs: avoid tree log commit when there are no changes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-07 10:25:24 +00:00
/*
* Don't update last_log_commit if we logged that an inode exists after
* it was loaded to memory (full_sync bit set).
* This is to prevent data loss when we do a write to the inode, then
* the inode gets evicted after all delalloc was flushed, then we log
* it exists (due to a rename for example) and then fsync it. This last
* fsync would do nothing (not logging the extents previously written).
*/
spin_lock(&inode->lock);
inode->logged_trans = trans->transid;
Btrfs: fix data loss after inode eviction, renaming it, and fsync it When we log an inode, regardless of logging it completely or only that it exists, we always update it as logged (logged_trans and last_log_commit fields of the inode are updated). This is generally fine and avoids future attempts to log it from having to do repeated work that brings no value. However, if we write data to a file, then evict its inode after all the dealloc was flushed (and ordered extents completed), rename the file and fsync it, we end up not logging the new extents, since the rename may result in logging that the inode exists in case the parent directory was logged before. The following reproducer shows and explains how this can happen: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ touch /mnt/dir/bar # Do a direct IO write instead of a buffered write because with a # buffered write we would need to make sure dealloc gets flushed and # complete before we do the inode eviction later, and we can not do that # from user space with call to things such as sync(2) since that results # in a transaction commit as well. $ xfs_io -d -c "pwrite -S 0xd3 0 4K" /mnt/dir/bar # Keep the directory dir in use while we evict inodes. We want our file # bar's inode to be evicted but we don't want our directory's inode to # be evicted (if it were evicted too, we would not be able to reproduce # the issue since the first fsync below, of file foo, would result in a # transaction commit. $ ( cd /mnt/dir; while true; do :; done ) & $ pid=$! # Wait a bit to give time for the background process to chdir. $ sleep 0.1 # Evict all inodes, except the inode for the directory dir because it is # currently in use by our background process. $ echo 2 > /proc/sys/vm/drop_caches # fsync file foo, which ends up persisting information about the parent # directory because it is a new inode. $ xfs_io -c fsync /mnt/dir/foo # Rename bar, this results in logging that this inode exists (inode item, # names, xattrs) because the parent directory is in the log. $ mv /mnt/dir/bar /mnt/dir/baz # Now fsync baz, which ends up doing absolutely nothing because of the # rename operation which logged that the inode exists only. $ xfs_io -c fsync /mnt/dir/baz <power failure> $ mount /dev/sdb /mnt $ od -t x1 -A d /mnt/dir/baz 0000000 --> Empty file, data we wrote is missing. Fix this by not updating last_sub_trans of an inode when we are logging only that it exists and the inode was not yet logged since it was loaded from disk (full_sync bit set), this is enough to make btrfs_inode_in_log() return false for this scenario and make us log the inode. The logged_trans of the inode is still always setsince that alone is used to track if names need to be deleted as part of unlink operations. Fixes: 257c62e1bce03e ("Btrfs: avoid tree log commit when there are no changes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-06-07 10:25:24 +00:00
if (inode_only != LOG_INODE_EXISTS ||
!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags))
inode->last_log_commit = inode->last_sub_trans;
spin_unlock(&inode->lock);
out_unlock:
mutex_unlock(&inode->log_mutex);
btrfs_free_path(path);
btrfs_free_path(dst_path);
return err;
}
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
/*
* Check if we must fallback to a transaction commit when logging an inode.
* This must be called after logging the inode and is used only in the context
* when fsyncing an inode requires the need to log some other inode - in which
* case we can't lock the i_mutex of each other inode we need to log as that
* can lead to deadlocks with concurrent fsync against other inodes (as we can
* log inodes up or down in the hierarchy) or rename operations for example. So
* we take the log_mutex of the inode after we have logged it and then check for
* its last_unlink_trans value - this is safe because any task setting
* last_unlink_trans must take the log_mutex and it must do this before it does
* the actual unlink operation, so if we do this check before a concurrent task
* sets last_unlink_trans it means we've logged a consistent version/state of
* all the inode items, otherwise we are not sure and must do a transaction
* commit (the concurrent task might have only updated last_unlink_trans before
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
* we logged the inode or it might have also done the unlink).
*/
static bool btrfs_must_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
bool ret = false;
mutex_lock(&inode->log_mutex);
if (inode->last_unlink_trans > fs_info->last_trans_committed) {
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
/*
* Make sure any commits to the log are forced to be full
* commits.
*/
btrfs_set_log_full_commit(trans);
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
ret = true;
}
mutex_unlock(&inode->log_mutex);
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
return ret;
}
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* follow the dentry parent pointers up the chain and see if any
* of the directories in it require a full commit before they can
* be logged. Returns zero if nothing special needs to be done or 1 if
* a full commit is required.
*/
static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
struct dentry *parent,
struct super_block *sb,
u64 last_committed)
{
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
int ret = 0;
struct dentry *old_parent = NULL;
/*
* for regular files, if its inode is already on disk, we don't
* have to worry about the parents at all. This is because
* we can use the last_unlink_trans field to record renames
* and other fun in this file.
*/
if (S_ISREG(inode->vfs_inode.i_mode) &&
inode->generation <= last_committed &&
inode->last_unlink_trans <= last_committed)
goto out;
if (!S_ISDIR(inode->vfs_inode.i_mode)) {
if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
goto out;
inode = BTRFS_I(d_inode(parent));
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
}
while (1) {
if (btrfs_must_commit_transaction(trans, inode)) {
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
ret = 1;
break;
}
if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
break;
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
if (IS_ROOT(parent)) {
inode = BTRFS_I(d_inode(parent));
if (btrfs_must_commit_transaction(trans, inode))
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
ret = 1;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
break;
Btrfs: improve performance on fsync against new inode after rename/unlink With commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") we got simple fix for a functional issue when the following sequence of actions is done: at transaction N create file A at directory D at transaction N + M (where M >= 1) move/rename existing file A from directory D to directory E create a new file named A at directory D fsync the new file power fail The solution was to simply detect such scenario and fallback to a full transaction commit when we detect it. However this turned out to had a significant impact on throughput (and a bit on latency too) for benchmarks using the dbench tool, which simulates real workloads from smbd (Samba) servers. For example on a test vm (with a debug kernel): Unpatched: Throughput 19.1572 MB/sec 32 clients 32 procs max_latency=1005.229 ms Patched: Throughput 23.7015 MB/sec 32 clients 32 procs max_latency=809.206 ms The patched results (this patch is applied) are similar to the results of a kernel with the commit 56f23fdbb600 ("Btrfs: fix file/data loss caused by fsync after rename and new inode") reverted. This change avoids the fallback to a transaction commit and instead makes sure all the names of the conflicting inode (the one that had a name in a past transaction that matches the name of the new file in the same parent directory) are logged so that at log replay time we don't lose neither the new file nor the old file, and the old file gets the name it was renamed to. This also ends up avoiding a full transaction commit for a similar case that involves an unlink instead of a rename of the old file: at transaction N create file A at directory D at transaction N + M (where M >= 1) remove file A create a new file named A at directory D fsync the new file power fail Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-06-06 15:11:13 +00:00
}
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
parent = dget_parent(parent);
dput(old_parent);
old_parent = parent;
inode = BTRFS_I(d_inode(parent));
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
}
dput(old_parent);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
out:
return ret;
}
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
struct btrfs_dir_list {
u64 ino;
struct list_head list;
};
/*
* Log the inodes of the new dentries of a directory. See log_dir_items() for
* details about the why it is needed.
* This is a recursive operation - if an existing dentry corresponds to a
* directory, that directory's new entries are logged too (same behaviour as
* ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
* the dentries point to we do not lock their i_mutex, otherwise lockdep
* complains about the following circular lock dependency / possible deadlock:
*
* CPU0 CPU1
* ---- ----
* lock(&type->i_mutex_dir_key#3/2);
* lock(sb_internal#2);
* lock(&type->i_mutex_dir_key#3/2);
* lock(&sb->s_type->i_mutex_key#14);
*
* Where sb_internal is the lock (a counter that works as a lock) acquired by
* sb_start_intwrite() in btrfs_start_transaction().
* Not locking i_mutex of the inodes is still safe because:
*
* 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
* that while logging the inode new references (names) are added or removed
* from the inode, leaving the logged inode item with a link count that does
* not match the number of logged inode reference items. This is fine because
* at log replay time we compute the real number of links and correct the
* link count in the inode item (see replay_one_buffer() and
* link_to_fixup_dir());
*
* 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
* while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and
* BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item
* has a size that doesn't match the sum of the lengths of all the logged
* names. This does not result in a problem because if a dir_item key is
* logged but its matching dir_index key is not logged, at log replay time we
* don't use it to replay the respective name (see replay_one_name()). On the
* other hand if only the dir_index key ends up being logged, the respective
* name is added to the fs/subvol tree with both the dir_item and dir_index
* keys created (see replay_one_name()).
* The directory's inode item with a wrong i_size is not a problem as well,
* since we don't use it at log replay time to set the i_size in the inode
* item of the fs/subvol tree (see overwrite_item()).
*/
static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *start_inode,
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
struct btrfs_root *log = root->log_root;
struct btrfs_path *path;
LIST_HEAD(dir_list);
struct btrfs_dir_list *dir_elem;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
if (!dir_elem) {
btrfs_free_path(path);
return -ENOMEM;
}
dir_elem->ino = btrfs_ino(start_inode);
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
list_add_tail(&dir_elem->list, &dir_list);
while (!list_empty(&dir_list)) {
struct extent_buffer *leaf;
struct btrfs_key min_key;
int nritems;
int i;
dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list,
list);
if (ret)
goto next_dir_inode;
min_key.objectid = dir_elem->ino;
min_key.type = BTRFS_DIR_ITEM_KEY;
min_key.offset = 0;
again:
btrfs_release_path(path);
ret = btrfs_search_forward(log, &min_key, path, trans->transid);
if (ret < 0) {
goto next_dir_inode;
} else if (ret > 0) {
ret = 0;
goto next_dir_inode;
}
process_leaf:
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key di_key;
struct inode *di_inode;
struct btrfs_dir_list *new_dir_elem;
int log_mode = LOG_INODE_EXISTS;
int type;
btrfs_item_key_to_cpu(leaf, &min_key, i);
if (min_key.objectid != dir_elem->ino ||
min_key.type != BTRFS_DIR_ITEM_KEY)
goto next_dir_inode;
di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
type = btrfs_dir_type(leaf, di);
if (btrfs_dir_transid(leaf, di) < trans->transid &&
type != BTRFS_FT_DIR)
continue;
btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
if (di_key.type == BTRFS_ROOT_ITEM_KEY)
continue;
Btrfs: fix deadlock caused by fsync when logging directory entries While logging new directory entries, at tree-log.c:log_new_dir_dentries(), after we call btrfs_search_forward() we get a leaf with a read lock on it, and without unlocking that leaf we can end up calling btrfs_iget() to get an inode pointer. The later (btrfs_iget()) can end up doing a read-only search on the same tree again, if the inode is not in memory already, which ends up causing a deadlock if some other task in the meanwhile started a write search on the tree and is attempting to write lock the same leaf that btrfs_search_forward() locked while holding write locks on upper levels of the tree blocking the read search from btrfs_iget(). In this scenario we get a deadlock. So fix this by releasing the search path before calling btrfs_iget() at tree-log.c:log_new_dir_dentries(). Example trace of such deadlock: [ 4077.478852] kworker/u24:10 D ffff88107fc90640 0 14431 2 0x00000000 [ 4077.486752] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [ 4077.494346] ffff880ffa56bad0 0000000000000046 0000000000009000 ffff880ffa56bfd8 [ 4077.502629] ffff880ffa56bfd8 ffff881016ce21c0 ffffffffa06ecb26 ffff88101a5d6138 [ 4077.510915] ffff880ebb5173b0 ffff880ffa56baf8 ffff880ebb517410 ffff881016ce21c0 [ 4077.519202] Call Trace: [ 4077.528752] [<ffffffffa06ed5ed>] ? btrfs_tree_lock+0xdd/0x2f0 [btrfs] [ 4077.536049] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4077.542574] [<ffffffffa068cc1f>] ? btrfs_search_slot+0x79f/0xb10 [btrfs] [ 4077.550171] [<ffffffffa06a5073>] ? btrfs_lookup_file_extent+0x33/0x40 [btrfs] [ 4077.558252] [<ffffffffa06c600b>] ? __btrfs_drop_extents+0x13b/0xdf0 [btrfs] [ 4077.566140] [<ffffffffa06fc9e2>] ? add_delayed_data_ref+0xe2/0x150 [btrfs] [ 4077.573928] [<ffffffffa06fd629>] ? btrfs_add_delayed_data_ref+0x149/0x1d0 [btrfs] [ 4077.582399] [<ffffffffa06cf3c0>] ? __set_extent_bit+0x4c0/0x5c0 [btrfs] [ 4077.589896] [<ffffffffa06b4a64>] ? insert_reserved_file_extent.constprop.75+0xa4/0x320 [btrfs] [ 4077.599632] [<ffffffffa06b206d>] ? start_transaction+0x8d/0x470 [btrfs] [ 4077.607134] [<ffffffffa06bab57>] ? btrfs_finish_ordered_io+0x2e7/0x600 [btrfs] [ 4077.615329] [<ffffffff8104cbc2>] ? process_one_work+0x142/0x3d0 [ 4077.622043] [<ffffffff8104d729>] ? worker_thread+0x109/0x3b0 [ 4077.628459] [<ffffffff8104d620>] ? manage_workers.isra.26+0x270/0x270 [ 4077.635759] [<ffffffff81052b0f>] ? kthread+0xaf/0xc0 [ 4077.641404] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4077.648696] [<ffffffff814a9ac8>] ? ret_from_fork+0x58/0x90 [ 4077.654926] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4078.358087] kworker/u24:15 D ffff88107fcd0640 0 14436 2 0x00000000 [ 4078.365981] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [ 4078.373574] ffff880ffa57fad0 0000000000000046 0000000000009000 ffff880ffa57ffd8 [ 4078.381864] ffff880ffa57ffd8 ffff88103004d0a0 ffffffffa06ecb26 ffff88101a5d6138 [ 4078.390163] ffff880fbeffc298 ffff880ffa57faf8 ffff880fbeffc2f8 ffff88103004d0a0 [ 4078.398466] Call Trace: [ 4078.408019] [<ffffffffa06ed5ed>] ? btrfs_tree_lock+0xdd/0x2f0 [btrfs] [ 4078.415322] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4078.421844] [<ffffffffa068cc1f>] ? btrfs_search_slot+0x79f/0xb10 [btrfs] [ 4078.429438] [<ffffffffa06a5073>] ? btrfs_lookup_file_extent+0x33/0x40 [btrfs] [ 4078.437518] [<ffffffffa06c600b>] ? __btrfs_drop_extents+0x13b/0xdf0 [btrfs] [ 4078.445404] [<ffffffffa06fc9e2>] ? add_delayed_data_ref+0xe2/0x150 [btrfs] [ 4078.453194] [<ffffffffa06fd629>] ? btrfs_add_delayed_data_ref+0x149/0x1d0 [btrfs] [ 4078.461663] [<ffffffffa06cf3c0>] ? __set_extent_bit+0x4c0/0x5c0 [btrfs] [ 4078.469161] [<ffffffffa06b4a64>] ? insert_reserved_file_extent.constprop.75+0xa4/0x320 [btrfs] [ 4078.478893] [<ffffffffa06b206d>] ? start_transaction+0x8d/0x470 [btrfs] [ 4078.486388] [<ffffffffa06bab57>] ? btrfs_finish_ordered_io+0x2e7/0x600 [btrfs] [ 4078.494561] [<ffffffff8104cbc2>] ? process_one_work+0x142/0x3d0 [ 4078.501278] [<ffffffff8104a507>] ? pwq_activate_delayed_work+0x27/0x40 [ 4078.508673] [<ffffffff8104d729>] ? worker_thread+0x109/0x3b0 [ 4078.515098] [<ffffffff8104d620>] ? manage_workers.isra.26+0x270/0x270 [ 4078.522396] [<ffffffff81052b0f>] ? kthread+0xaf/0xc0 [ 4078.528032] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4078.535325] [<ffffffff814a9ac8>] ? ret_from_fork+0x58/0x90 [ 4078.541552] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4079.355824] user-space-program D ffff88107fd30640 0 32020 1 0x00000000 [ 4079.363716] ffff880eae8eba10 0000000000000086 0000000000009000 ffff880eae8ebfd8 [ 4079.372003] ffff880eae8ebfd8 ffff881016c162c0 ffffffffa06ecb26 ffff88101a5d6138 [ 4079.380294] ffff880fbed4b4c8 ffff880eae8eba38 ffff880fbed4b528 ffff881016c162c0 [ 4079.388586] Call Trace: [ 4079.398134] [<ffffffffa06ed595>] ? btrfs_tree_lock+0x85/0x2f0 [btrfs] [ 4079.405431] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4079.411955] [<ffffffffa06876fb>] ? btrfs_lock_root_node+0x2b/0x40 [btrfs] [ 4079.419644] [<ffffffffa068ce83>] ? btrfs_search_slot+0xa03/0xb10 [btrfs] [ 4079.427237] [<ffffffffa06aba52>] ? btrfs_buffer_uptodate+0x52/0x70 [btrfs] [ 4079.435041] [<ffffffffa0689b60>] ? generic_bin_search.constprop.38+0x80/0x190 [btrfs] [ 4079.443897] [<ffffffffa068ea44>] ? btrfs_insert_empty_items+0x74/0xd0 [btrfs] [ 4079.451975] [<ffffffffa072c443>] ? copy_items+0x128/0x850 [btrfs] [ 4079.458890] [<ffffffffa072da10>] ? btrfs_log_inode+0x629/0xbf3 [btrfs] [ 4079.466292] [<ffffffffa06f34a1>] ? btrfs_log_inode_parent+0xc61/0xf30 [btrfs] [ 4079.474373] [<ffffffffa06f45a9>] ? btrfs_log_dentry_safe+0x59/0x80 [btrfs] [ 4079.482161] [<ffffffffa06c298d>] ? btrfs_sync_file+0x20d/0x330 [btrfs] [ 4079.489558] [<ffffffff8112777c>] ? do_fsync+0x4c/0x80 [ 4079.495300] [<ffffffff81127a0a>] ? SyS_fdatasync+0xa/0x10 [ 4079.501422] [<ffffffff814a9b72>] ? system_call_fastpath+0x16/0x1b [ 4079.508334] user-space-program D ffff88107fc30640 0 32021 1 0x00000004 [ 4079.516226] ffff880eae8efbf8 0000000000000086 0000000000009000 ffff880eae8effd8 [ 4079.524513] ffff880eae8effd8 ffff881030279610 ffffffffa06ecb26 ffff88101a5d6138 [ 4079.532802] ffff880ebb671d88 ffff880eae8efc20 ffff880ebb671de8 ffff881030279610 [ 4079.541092] Call Trace: [ 4079.550642] [<ffffffffa06ed595>] ? btrfs_tree_lock+0x85/0x2f0 [btrfs] [ 4079.557941] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4079.564463] [<ffffffffa068cc1f>] ? btrfs_search_slot+0x79f/0xb10 [btrfs] [ 4079.572058] [<ffffffffa06bb7d8>] ? btrfs_truncate_inode_items+0x168/0xb90 [btrfs] [ 4079.580526] [<ffffffffa06b04be>] ? join_transaction.isra.15+0x1e/0x3a0 [btrfs] [ 4079.588701] [<ffffffffa06b206d>] ? start_transaction+0x8d/0x470 [btrfs] [ 4079.596196] [<ffffffffa0690ac6>] ? block_rsv_add_bytes+0x16/0x50 [btrfs] [ 4079.603789] [<ffffffffa06bc2e9>] ? btrfs_truncate+0xe9/0x2e0 [btrfs] [ 4079.610994] [<ffffffffa06bd00b>] ? btrfs_setattr+0x30b/0x410 [btrfs] [ 4079.618197] [<ffffffff81117c1c>] ? notify_change+0x1dc/0x680 [ 4079.624625] [<ffffffff8123c8a4>] ? aa_path_perm+0xd4/0x160 [ 4079.630854] [<ffffffff810f4fcb>] ? do_truncate+0x5b/0x90 [ 4079.636889] [<ffffffff810f59fa>] ? do_sys_ftruncate.constprop.15+0x10a/0x160 [ 4079.644869] [<ffffffff8110d87b>] ? SyS_fcntl+0x5b/0x570 [ 4079.650805] [<ffffffff814a9b72>] ? system_call_fastpath+0x16/0x1b [ 4080.410607] user-space-program D ffff88107fc70640 0 32028 12639 0x00000004 [ 4080.418489] ffff880eaeccbbe0 0000000000000086 0000000000009000 ffff880eaeccbfd8 [ 4080.426778] ffff880eaeccbfd8 ffff880f317ef1e0 ffffffffa06ecb26 ffff88101a5d6138 [ 4080.435067] ffff880ef7e93928 ffff880f317ef1e0 ffff880eaeccbc08 ffff880f317ef1e0 [ 4080.443353] Call Trace: [ 4080.452920] [<ffffffffa06ed15d>] ? btrfs_tree_read_lock+0xdd/0x190 [btrfs] [ 4080.460703] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4080.467225] [<ffffffffa06876bb>] ? btrfs_read_lock_root_node+0x2b/0x40 [btrfs] [ 4080.475400] [<ffffffffa068cc81>] ? btrfs_search_slot+0x801/0xb10 [btrfs] [ 4080.482994] [<ffffffffa06b2df0>] ? btrfs_clean_one_deleted_snapshot+0xe0/0xe0 [btrfs] [ 4080.491857] [<ffffffffa06a70a6>] ? btrfs_lookup_inode+0x26/0x90 [btrfs] [ 4080.499353] [<ffffffff810ec42f>] ? kmem_cache_alloc+0xaf/0xc0 [ 4080.505879] [<ffffffffa06bd905>] ? btrfs_iget+0xd5/0x5d0 [btrfs] [ 4080.512696] [<ffffffffa06caf04>] ? btrfs_get_token_64+0x104/0x120 [btrfs] [ 4080.520387] [<ffffffffa06f341f>] ? btrfs_log_inode_parent+0xbdf/0xf30 [btrfs] [ 4080.528469] [<ffffffffa06f45a9>] ? btrfs_log_dentry_safe+0x59/0x80 [btrfs] [ 4080.536258] [<ffffffffa06c298d>] ? btrfs_sync_file+0x20d/0x330 [btrfs] [ 4080.543657] [<ffffffff8112777c>] ? do_fsync+0x4c/0x80 [ 4080.549399] [<ffffffff81127a0a>] ? SyS_fdatasync+0xa/0x10 [ 4080.555534] [<ffffffff814a9b72>] ? system_call_fastpath+0x16/0x1b Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Fixes: 2f2ff0ee5e43 (Btrfs: fix metadata inconsistencies after directory fsync) Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Filipe Manana <fdmanana@suse.com> [Modified changelog for clarity and correctness]
2016-10-28 02:48:26 +00:00
btrfs_release_path(path);
di_inode = btrfs_iget(fs_info->sb, &di_key, root, NULL);
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
if (IS_ERR(di_inode)) {
ret = PTR_ERR(di_inode);
goto next_dir_inode;
}
if (btrfs_inode_in_log(BTRFS_I(di_inode), trans->transid)) {
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
iput(di_inode);
Btrfs: fix deadlock caused by fsync when logging directory entries While logging new directory entries, at tree-log.c:log_new_dir_dentries(), after we call btrfs_search_forward() we get a leaf with a read lock on it, and without unlocking that leaf we can end up calling btrfs_iget() to get an inode pointer. The later (btrfs_iget()) can end up doing a read-only search on the same tree again, if the inode is not in memory already, which ends up causing a deadlock if some other task in the meanwhile started a write search on the tree and is attempting to write lock the same leaf that btrfs_search_forward() locked while holding write locks on upper levels of the tree blocking the read search from btrfs_iget(). In this scenario we get a deadlock. So fix this by releasing the search path before calling btrfs_iget() at tree-log.c:log_new_dir_dentries(). Example trace of such deadlock: [ 4077.478852] kworker/u24:10 D ffff88107fc90640 0 14431 2 0x00000000 [ 4077.486752] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [ 4077.494346] ffff880ffa56bad0 0000000000000046 0000000000009000 ffff880ffa56bfd8 [ 4077.502629] ffff880ffa56bfd8 ffff881016ce21c0 ffffffffa06ecb26 ffff88101a5d6138 [ 4077.510915] ffff880ebb5173b0 ffff880ffa56baf8 ffff880ebb517410 ffff881016ce21c0 [ 4077.519202] Call Trace: [ 4077.528752] [<ffffffffa06ed5ed>] ? btrfs_tree_lock+0xdd/0x2f0 [btrfs] [ 4077.536049] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4077.542574] [<ffffffffa068cc1f>] ? btrfs_search_slot+0x79f/0xb10 [btrfs] [ 4077.550171] [<ffffffffa06a5073>] ? btrfs_lookup_file_extent+0x33/0x40 [btrfs] [ 4077.558252] [<ffffffffa06c600b>] ? __btrfs_drop_extents+0x13b/0xdf0 [btrfs] [ 4077.566140] [<ffffffffa06fc9e2>] ? add_delayed_data_ref+0xe2/0x150 [btrfs] [ 4077.573928] [<ffffffffa06fd629>] ? btrfs_add_delayed_data_ref+0x149/0x1d0 [btrfs] [ 4077.582399] [<ffffffffa06cf3c0>] ? __set_extent_bit+0x4c0/0x5c0 [btrfs] [ 4077.589896] [<ffffffffa06b4a64>] ? insert_reserved_file_extent.constprop.75+0xa4/0x320 [btrfs] [ 4077.599632] [<ffffffffa06b206d>] ? start_transaction+0x8d/0x470 [btrfs] [ 4077.607134] [<ffffffffa06bab57>] ? btrfs_finish_ordered_io+0x2e7/0x600 [btrfs] [ 4077.615329] [<ffffffff8104cbc2>] ? process_one_work+0x142/0x3d0 [ 4077.622043] [<ffffffff8104d729>] ? worker_thread+0x109/0x3b0 [ 4077.628459] [<ffffffff8104d620>] ? manage_workers.isra.26+0x270/0x270 [ 4077.635759] [<ffffffff81052b0f>] ? kthread+0xaf/0xc0 [ 4077.641404] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4077.648696] [<ffffffff814a9ac8>] ? ret_from_fork+0x58/0x90 [ 4077.654926] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4078.358087] kworker/u24:15 D ffff88107fcd0640 0 14436 2 0x00000000 [ 4078.365981] Workqueue: btrfs-endio-write btrfs_endio_write_helper [btrfs] [ 4078.373574] ffff880ffa57fad0 0000000000000046 0000000000009000 ffff880ffa57ffd8 [ 4078.381864] ffff880ffa57ffd8 ffff88103004d0a0 ffffffffa06ecb26 ffff88101a5d6138 [ 4078.390163] ffff880fbeffc298 ffff880ffa57faf8 ffff880fbeffc2f8 ffff88103004d0a0 [ 4078.398466] Call Trace: [ 4078.408019] [<ffffffffa06ed5ed>] ? btrfs_tree_lock+0xdd/0x2f0 [btrfs] [ 4078.415322] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4078.421844] [<ffffffffa068cc1f>] ? btrfs_search_slot+0x79f/0xb10 [btrfs] [ 4078.429438] [<ffffffffa06a5073>] ? btrfs_lookup_file_extent+0x33/0x40 [btrfs] [ 4078.437518] [<ffffffffa06c600b>] ? __btrfs_drop_extents+0x13b/0xdf0 [btrfs] [ 4078.445404] [<ffffffffa06fc9e2>] ? add_delayed_data_ref+0xe2/0x150 [btrfs] [ 4078.453194] [<ffffffffa06fd629>] ? btrfs_add_delayed_data_ref+0x149/0x1d0 [btrfs] [ 4078.461663] [<ffffffffa06cf3c0>] ? __set_extent_bit+0x4c0/0x5c0 [btrfs] [ 4078.469161] [<ffffffffa06b4a64>] ? insert_reserved_file_extent.constprop.75+0xa4/0x320 [btrfs] [ 4078.478893] [<ffffffffa06b206d>] ? start_transaction+0x8d/0x470 [btrfs] [ 4078.486388] [<ffffffffa06bab57>] ? btrfs_finish_ordered_io+0x2e7/0x600 [btrfs] [ 4078.494561] [<ffffffff8104cbc2>] ? process_one_work+0x142/0x3d0 [ 4078.501278] [<ffffffff8104a507>] ? pwq_activate_delayed_work+0x27/0x40 [ 4078.508673] [<ffffffff8104d729>] ? worker_thread+0x109/0x3b0 [ 4078.515098] [<ffffffff8104d620>] ? manage_workers.isra.26+0x270/0x270 [ 4078.522396] [<ffffffff81052b0f>] ? kthread+0xaf/0xc0 [ 4078.528032] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4078.535325] [<ffffffff814a9ac8>] ? ret_from_fork+0x58/0x90 [ 4078.541552] [<ffffffff81052a60>] ? kthread_create_on_node+0x110/0x110 [ 4079.355824] user-space-program D ffff88107fd30640 0 32020 1 0x00000000 [ 4079.363716] ffff880eae8eba10 0000000000000086 0000000000009000 ffff880eae8ebfd8 [ 4079.372003] ffff880eae8ebfd8 ffff881016c162c0 ffffffffa06ecb26 ffff88101a5d6138 [ 4079.380294] ffff880fbed4b4c8 ffff880eae8eba38 ffff880fbed4b528 ffff881016c162c0 [ 4079.388586] Call Trace: [ 4079.398134] [<ffffffffa06ed595>] ? btrfs_tree_lock+0x85/0x2f0 [btrfs] [ 4079.405431] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4079.411955] [<ffffffffa06876fb>] ? btrfs_lock_root_node+0x2b/0x40 [btrfs] [ 4079.419644] [<ffffffffa068ce83>] ? btrfs_search_slot+0xa03/0xb10 [btrfs] [ 4079.427237] [<ffffffffa06aba52>] ? btrfs_buffer_uptodate+0x52/0x70 [btrfs] [ 4079.435041] [<ffffffffa0689b60>] ? generic_bin_search.constprop.38+0x80/0x190 [btrfs] [ 4079.443897] [<ffffffffa068ea44>] ? btrfs_insert_empty_items+0x74/0xd0 [btrfs] [ 4079.451975] [<ffffffffa072c443>] ? copy_items+0x128/0x850 [btrfs] [ 4079.458890] [<ffffffffa072da10>] ? btrfs_log_inode+0x629/0xbf3 [btrfs] [ 4079.466292] [<ffffffffa06f34a1>] ? btrfs_log_inode_parent+0xc61/0xf30 [btrfs] [ 4079.474373] [<ffffffffa06f45a9>] ? btrfs_log_dentry_safe+0x59/0x80 [btrfs] [ 4079.482161] [<ffffffffa06c298d>] ? btrfs_sync_file+0x20d/0x330 [btrfs] [ 4079.489558] [<ffffffff8112777c>] ? do_fsync+0x4c/0x80 [ 4079.495300] [<ffffffff81127a0a>] ? SyS_fdatasync+0xa/0x10 [ 4079.501422] [<ffffffff814a9b72>] ? system_call_fastpath+0x16/0x1b [ 4079.508334] user-space-program D ffff88107fc30640 0 32021 1 0x00000004 [ 4079.516226] ffff880eae8efbf8 0000000000000086 0000000000009000 ffff880eae8effd8 [ 4079.524513] ffff880eae8effd8 ffff881030279610 ffffffffa06ecb26 ffff88101a5d6138 [ 4079.532802] ffff880ebb671d88 ffff880eae8efc20 ffff880ebb671de8 ffff881030279610 [ 4079.541092] Call Trace: [ 4079.550642] [<ffffffffa06ed595>] ? btrfs_tree_lock+0x85/0x2f0 [btrfs] [ 4079.557941] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4079.564463] [<ffffffffa068cc1f>] ? btrfs_search_slot+0x79f/0xb10 [btrfs] [ 4079.572058] [<ffffffffa06bb7d8>] ? btrfs_truncate_inode_items+0x168/0xb90 [btrfs] [ 4079.580526] [<ffffffffa06b04be>] ? join_transaction.isra.15+0x1e/0x3a0 [btrfs] [ 4079.588701] [<ffffffffa06b206d>] ? start_transaction+0x8d/0x470 [btrfs] [ 4079.596196] [<ffffffffa0690ac6>] ? block_rsv_add_bytes+0x16/0x50 [btrfs] [ 4079.603789] [<ffffffffa06bc2e9>] ? btrfs_truncate+0xe9/0x2e0 [btrfs] [ 4079.610994] [<ffffffffa06bd00b>] ? btrfs_setattr+0x30b/0x410 [btrfs] [ 4079.618197] [<ffffffff81117c1c>] ? notify_change+0x1dc/0x680 [ 4079.624625] [<ffffffff8123c8a4>] ? aa_path_perm+0xd4/0x160 [ 4079.630854] [<ffffffff810f4fcb>] ? do_truncate+0x5b/0x90 [ 4079.636889] [<ffffffff810f59fa>] ? do_sys_ftruncate.constprop.15+0x10a/0x160 [ 4079.644869] [<ffffffff8110d87b>] ? SyS_fcntl+0x5b/0x570 [ 4079.650805] [<ffffffff814a9b72>] ? system_call_fastpath+0x16/0x1b [ 4080.410607] user-space-program D ffff88107fc70640 0 32028 12639 0x00000004 [ 4080.418489] ffff880eaeccbbe0 0000000000000086 0000000000009000 ffff880eaeccbfd8 [ 4080.426778] ffff880eaeccbfd8 ffff880f317ef1e0 ffffffffa06ecb26 ffff88101a5d6138 [ 4080.435067] ffff880ef7e93928 ffff880f317ef1e0 ffff880eaeccbc08 ffff880f317ef1e0 [ 4080.443353] Call Trace: [ 4080.452920] [<ffffffffa06ed15d>] ? btrfs_tree_read_lock+0xdd/0x190 [btrfs] [ 4080.460703] [<ffffffff81053680>] ? wake_up_atomic_t+0x30/0x30 [ 4080.467225] [<ffffffffa06876bb>] ? btrfs_read_lock_root_node+0x2b/0x40 [btrfs] [ 4080.475400] [<ffffffffa068cc81>] ? btrfs_search_slot+0x801/0xb10 [btrfs] [ 4080.482994] [<ffffffffa06b2df0>] ? btrfs_clean_one_deleted_snapshot+0xe0/0xe0 [btrfs] [ 4080.491857] [<ffffffffa06a70a6>] ? btrfs_lookup_inode+0x26/0x90 [btrfs] [ 4080.499353] [<ffffffff810ec42f>] ? kmem_cache_alloc+0xaf/0xc0 [ 4080.505879] [<ffffffffa06bd905>] ? btrfs_iget+0xd5/0x5d0 [btrfs] [ 4080.512696] [<ffffffffa06caf04>] ? btrfs_get_token_64+0x104/0x120 [btrfs] [ 4080.520387] [<ffffffffa06f341f>] ? btrfs_log_inode_parent+0xbdf/0xf30 [btrfs] [ 4080.528469] [<ffffffffa06f45a9>] ? btrfs_log_dentry_safe+0x59/0x80 [btrfs] [ 4080.536258] [<ffffffffa06c298d>] ? btrfs_sync_file+0x20d/0x330 [btrfs] [ 4080.543657] [<ffffffff8112777c>] ? do_fsync+0x4c/0x80 [ 4080.549399] [<ffffffff81127a0a>] ? SyS_fdatasync+0xa/0x10 [ 4080.555534] [<ffffffff814a9b72>] ? system_call_fastpath+0x16/0x1b Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Fixes: 2f2ff0ee5e43 (Btrfs: fix metadata inconsistencies after directory fsync) Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Filipe Manana <fdmanana@suse.com> [Modified changelog for clarity and correctness]
2016-10-28 02:48:26 +00:00
break;
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
}
ctx->log_new_dentries = false;
if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK)
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
log_mode = LOG_INODE_ALL;
ret = btrfs_log_inode(trans, root, BTRFS_I(di_inode),
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
log_mode, 0, LLONG_MAX, ctx);
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
if (!ret &&
btrfs_must_commit_transaction(trans, BTRFS_I(di_inode)))
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
ret = 1;
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
iput(di_inode);
if (ret)
goto next_dir_inode;
if (ctx->log_new_dentries) {
new_dir_elem = kmalloc(sizeof(*new_dir_elem),
GFP_NOFS);
if (!new_dir_elem) {
ret = -ENOMEM;
goto next_dir_inode;
}
new_dir_elem->ino = di_key.objectid;
list_add_tail(&new_dir_elem->list, &dir_list);
}
break;
}
if (i == nritems) {
ret = btrfs_next_leaf(log, path);
if (ret < 0) {
goto next_dir_inode;
} else if (ret > 0) {
ret = 0;
goto next_dir_inode;
}
goto process_leaf;
}
if (min_key.offset < (u64)-1) {
min_key.offset++;
goto again;
}
next_dir_inode:
list_del(&dir_elem->list);
kfree(dir_elem);
}
btrfs_free_path(path);
return ret;
}
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->skip_locking = 1;
path->search_commit_root = 1;
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
u32 cur_offset = 0;
u32 item_size;
unsigned long ptr;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
/* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
break;
item_size = btrfs_item_size_nr(leaf, slot);
ptr = btrfs_item_ptr_offset(leaf, slot);
while (cur_offset < item_size) {
struct btrfs_key inode_key;
struct inode *dir_inode;
inode_key.type = BTRFS_INODE_ITEM_KEY;
inode_key.offset = 0;
if (key.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)
(ptr + cur_offset);
inode_key.objectid = btrfs_inode_extref_parent(
leaf, extref);
cur_offset += sizeof(*extref);
cur_offset += btrfs_inode_extref_name_len(leaf,
extref);
} else {
inode_key.objectid = key.offset;
cur_offset = item_size;
}
dir_inode = btrfs_iget(fs_info->sb, &inode_key,
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
root, NULL);
/*
* If the parent inode was deleted, return an error to
* fallback to a transaction commit. This is to prevent
* getting an inode that was moved from one parent A to
* a parent B, got its former parent A deleted and then
* it got fsync'ed, from existing at both parents after
* a log replay (and the old parent still existing).
* Example:
*
* mkdir /mnt/A
* mkdir /mnt/B
* touch /mnt/B/bar
* sync
* mv /mnt/B/bar /mnt/A/bar
* mv -T /mnt/A /mnt/B
* fsync /mnt/B/bar
* <power fail>
*
* If we ignore the old parent B which got deleted,
* after a log replay we would have file bar linked
* at both parents and the old parent B would still
* exist.
*/
if (IS_ERR(dir_inode)) {
ret = PTR_ERR(dir_inode);
goto out;
}
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
Btrfs: fix for incorrect directory entries after fsync log replay If we move a directory to a new parent and later log that parent and don't explicitly log the old parent, when we replay the log we can end up with entries for the moved directory in both the old and new parent directories. Besides being ilegal to have directories with multiple hard links in linux, it also resulted in the leaving the inode item with a link count of 1. A similar issue also happens if we move a regular file - after the log tree is replayed the file has a link in both the old and new parent directories, when it should be only at the new directory. Sample reproducer: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/x $ mkdir /mnt/y $ touch /mnt/x/foo $ mkdir /mnt/y/z $ sync $ ln /mnt/x/foo /mnt/x/bar $ mv /mnt/y/z /mnt/x/z < power fail > $ mount /dev/sdc /mnt $ ls -1Ri /mnt /mnt: 257 x 258 y /mnt/x: 259 bar 259 foo 260 z /mnt/x/z: /mnt/y: 260 z /mnt/y/z: $ umount /dev/sdc $ btrfs check /dev/sdc Checking filesystem on /dev/sdc UUID: a67e2c4a-a4b4-4fdc-b015-9d9af1e344be checking extents checking free space cache checking fs roots root 5 inode 260 errors 2000, link count wrong unresolved ref dir 257 index 4 namelen 1 name z filetype 2 errors 0 unresolved ref dir 258 index 2 namelen 1 name z filetype 2 errors 0 (...) Attempting to remove the directory becomes impossible: $ mount /dev/sdc /mnt $ rmdir /mnt/y/z $ ls -lh /mnt/y ls: cannot access /mnt/y/z: No such file or directory total 0 d????????? ? ? ? ? ? z $ rmdir /mnt/x/z rmdir: failed to remove ‘/mnt/x/z’: Stale file handle $ ls -lh /mnt/x ls: cannot access /mnt/x/z: Stale file handle total 0 -rw-r--r-- 2 root root 0 Apr 6 18:06 bar -rw-r--r-- 2 root root 0 Apr 6 18:06 foo d????????? ? ? ? ? ? z So make sure that on rename we set the last_unlink_trans value for our inode, even if it's a directory, to the value of the current transaction's ID and that if the new parent directory is logged that we fallback to a transaction commit. A test case for fstests is being submitted as well. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-04-06 16:11:56 +00:00
if (ctx)
ctx->log_new_dentries = false;
ret = btrfs_log_inode(trans, root, BTRFS_I(dir_inode),
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
LOG_INODE_ALL, 0, LLONG_MAX, ctx);
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
if (!ret &&
btrfs_must_commit_transaction(trans, BTRFS_I(dir_inode)))
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
ret = 1;
Btrfs: fix for incorrect directory entries after fsync log replay If we move a directory to a new parent and later log that parent and don't explicitly log the old parent, when we replay the log we can end up with entries for the moved directory in both the old and new parent directories. Besides being ilegal to have directories with multiple hard links in linux, it also resulted in the leaving the inode item with a link count of 1. A similar issue also happens if we move a regular file - after the log tree is replayed the file has a link in both the old and new parent directories, when it should be only at the new directory. Sample reproducer: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/x $ mkdir /mnt/y $ touch /mnt/x/foo $ mkdir /mnt/y/z $ sync $ ln /mnt/x/foo /mnt/x/bar $ mv /mnt/y/z /mnt/x/z < power fail > $ mount /dev/sdc /mnt $ ls -1Ri /mnt /mnt: 257 x 258 y /mnt/x: 259 bar 259 foo 260 z /mnt/x/z: /mnt/y: 260 z /mnt/y/z: $ umount /dev/sdc $ btrfs check /dev/sdc Checking filesystem on /dev/sdc UUID: a67e2c4a-a4b4-4fdc-b015-9d9af1e344be checking extents checking free space cache checking fs roots root 5 inode 260 errors 2000, link count wrong unresolved ref dir 257 index 4 namelen 1 name z filetype 2 errors 0 unresolved ref dir 258 index 2 namelen 1 name z filetype 2 errors 0 (...) Attempting to remove the directory becomes impossible: $ mount /dev/sdc /mnt $ rmdir /mnt/y/z $ ls -lh /mnt/y ls: cannot access /mnt/y/z: No such file or directory total 0 d????????? ? ? ? ? ? z $ rmdir /mnt/x/z rmdir: failed to remove ‘/mnt/x/z’: Stale file handle $ ls -lh /mnt/x ls: cannot access /mnt/x/z: Stale file handle total 0 -rw-r--r-- 2 root root 0 Apr 6 18:06 bar -rw-r--r-- 2 root root 0 Apr 6 18:06 foo d????????? ? ? ? ? ? z So make sure that on rename we set the last_unlink_trans value for our inode, even if it's a directory, to the value of the current transaction's ID and that if the new parent directory is logged that we fallback to a transaction commit. A test case for fstests is being submitted as well. Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-04-06 16:11:56 +00:00
if (!ret && ctx && ctx->log_new_dentries)
ret = log_new_dir_dentries(trans, root,
BTRFS_I(dir_inode), ctx);
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
iput(dir_inode);
if (ret)
goto out;
}
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
static int log_new_ancestors(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_key found_key;
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
while (true) {
struct btrfs_fs_info *fs_info = root->fs_info;
const u64 last_committed = fs_info->last_trans_committed;
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_key search_key;
struct inode *inode;
int ret = 0;
btrfs_release_path(path);
search_key.objectid = found_key.offset;
search_key.type = BTRFS_INODE_ITEM_KEY;
search_key.offset = 0;
inode = btrfs_iget(fs_info->sb, &search_key, root, NULL);
if (IS_ERR(inode))
return PTR_ERR(inode);
if (BTRFS_I(inode)->generation > last_committed)
ret = btrfs_log_inode(trans, root, BTRFS_I(inode),
LOG_INODE_EXISTS,
0, LLONG_MAX, ctx);
iput(inode);
if (ret)
return ret;
if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
break;
search_key.type = BTRFS_INODE_REF_KEY;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
return ret;
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
return -ENOENT;
leaf = path->nodes[0];
slot = path->slots[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != search_key.objectid ||
found_key.type != BTRFS_INODE_REF_KEY)
return -ENOENT;
}
return 0;
}
static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct dentry *old_parent = NULL;
struct super_block *sb = inode->vfs_inode.i_sb;
int ret = 0;
while (true) {
if (!parent || d_really_is_negative(parent) ||
sb != parent->d_sb)
break;
inode = BTRFS_I(d_inode(parent));
if (root != inode->root)
break;
if (inode->generation > fs_info->last_trans_committed) {
ret = btrfs_log_inode(trans, root, inode,
LOG_INODE_EXISTS, 0, LLONG_MAX, ctx);
if (ret)
break;
}
if (IS_ROOT(parent))
break;
parent = dget_parent(parent);
dput(old_parent);
old_parent = parent;
}
dput(old_parent);
return ret;
}
static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
struct btrfs_path *path;
struct btrfs_key search_key;
int ret;
/*
* For a single hard link case, go through a fast path that does not
* need to iterate the fs/subvolume tree.
*/
if (inode->vfs_inode.i_nlink < 2)
return log_new_ancestors_fast(trans, inode, parent, ctx);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
if (ret == 0)
path->slots[0]++;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_key found_key;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != ino ||
found_key.type > BTRFS_INODE_EXTREF_KEY)
break;
/*
* Don't deal with extended references because they are rare
* cases and too complex to deal with (we would need to keep
* track of which subitem we are processing for each item in
* this loop, etc). So just return some error to fallback to
* a transaction commit.
*/
if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
ret = -EMLINK;
goto out;
}
/*
* Logging ancestors needs to do more searches on the fs/subvol
* tree, so it releases the path as needed to avoid deadlocks.
* Keep track of the last inode ref key and resume from that key
* after logging all new ancestors for the current hard link.
*/
memcpy(&search_key, &found_key, sizeof(search_key));
ret = log_new_ancestors(trans, root, path, ctx);
if (ret)
goto out;
btrfs_release_path(path);
goto again;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function around btrfs_log_inode to make sure newly created
* parent directories also end up in the log. A minimal inode and backref
* only logging is done of any parent directories that are older than
* the last committed transaction
*/
static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
const loff_t start,
const loff_t end,
int inode_only,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct super_block *sb;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
int ret = 0;
u64 last_committed = fs_info->last_trans_committed;
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
bool log_dentries = false;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
sb = inode->vfs_inode.i_sb;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
if (btrfs_test_opt(fs_info, NOTREELOG)) {
ret = 1;
goto end_no_trans;
}
/*
* The prev transaction commit doesn't complete, we need do
* full commit by ourselves.
*/
if (fs_info->last_trans_log_full_commit >
fs_info->last_trans_committed) {
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
ret = 1;
goto end_no_trans;
}
if (btrfs_root_refs(&root->root_item) == 0) {
ret = 1;
goto end_no_trans;
}
ret = check_parent_dirs_for_sync(trans, inode, parent, sb,
last_committed);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
if (ret)
goto end_no_trans;
Btrfs: fix warning when replaying log after fsync of a tmpfile When replaying a log which contains a tmpfile (which necessarily has a link count of 0) we end up calling inc_nlink(), at fs/btrfs/tree-log.c:replay_one_buffer(), which produces a warning like the following: [195191.943673] WARNING: CPU: 0 PID: 6924 at fs/inode.c:342 inc_nlink+0x33/0x40 [195191.943723] CPU: 0 PID: 6924 Comm: mount Not tainted 4.19.0-rc6-btrfs-next-38 #1 [195191.943724] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [195191.943726] RIP: 0010:inc_nlink+0x33/0x40 [195191.943728] RSP: 0018:ffffb96e425e3870 EFLAGS: 00010246 [195191.943730] RAX: 0000000000000000 RBX: ffff8c0d1e6af4f0 RCX: 0000000000000006 [195191.943731] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8c0d1e6af4f0 [195191.943731] RBP: 0000000000000097 R08: 0000000000000001 R09: 0000000000000000 [195191.943732] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb96e425e3a60 [195191.943733] R13: ffff8c0d10cff0c8 R14: ffff8c0d0d515348 R15: ffff8c0d78a1b3f8 [195191.943735] FS: 00007f570ee24480(0000) GS:ffff8c0dfb200000(0000) knlGS:0000000000000000 [195191.943736] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [195191.943737] CR2: 00005593286277c8 CR3: 00000000bb8f2006 CR4: 00000000003606f0 [195191.943739] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [195191.943740] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [195191.943741] Call Trace: [195191.943778] replay_one_buffer+0x797/0x7d0 [btrfs] [195191.943802] walk_up_log_tree+0x1c1/0x250 [btrfs] [195191.943809] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943825] walk_log_tree+0xae/0x1d0 [btrfs] [195191.943840] btrfs_recover_log_trees+0x1d7/0x4d0 [btrfs] [195191.943856] ? replay_dir_deletes+0x280/0x280 [btrfs] [195191.943870] open_ctree+0x1c3b/0x22a0 [btrfs] [195191.943887] btrfs_mount_root+0x6b4/0x800 [btrfs] [195191.943894] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943899] ? pcpu_alloc+0x55b/0x7c0 [195191.943906] ? mount_fs+0x3b/0x140 [195191.943908] mount_fs+0x3b/0x140 [195191.943912] ? __init_waitqueue_head+0x36/0x50 [195191.943916] vfs_kern_mount+0x62/0x160 [195191.943927] btrfs_mount+0x134/0x890 [btrfs] [195191.943936] ? rcu_read_lock_sched_held+0x3f/0x70 [195191.943938] ? pcpu_alloc+0x55b/0x7c0 [195191.943943] ? mount_fs+0x3b/0x140 [195191.943952] ? btrfs_remount+0x570/0x570 [btrfs] [195191.943954] mount_fs+0x3b/0x140 [195191.943956] ? __init_waitqueue_head+0x36/0x50 [195191.943960] vfs_kern_mount+0x62/0x160 [195191.943963] do_mount+0x1f9/0xd40 [195191.943967] ? memdup_user+0x4b/0x70 [195191.943971] ksys_mount+0x7e/0xd0 [195191.943974] __x64_sys_mount+0x21/0x30 [195191.943977] do_syscall_64+0x60/0x1b0 [195191.943980] entry_SYSCALL_64_after_hwframe+0x49/0xbe [195191.943983] RIP: 0033:0x7f570e4e524a [195191.943986] RSP: 002b:00007ffd83589478 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 [195191.943989] RAX: ffffffffffffffda RBX: 0000563f335b2060 RCX: 00007f570e4e524a [195191.943990] RDX: 0000563f335b2240 RSI: 0000563f335b2280 RDI: 0000563f335b2260 [195191.943992] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000020 [195191.943993] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000563f335b2260 [195191.943994] R13: 0000563f335b2240 R14: 0000000000000000 R15: 00000000ffffffff [195191.944002] irq event stamp: 8688 [195191.944010] hardirqs last enabled at (8687): [<ffffffff9cb004c3>] console_unlock+0x503/0x640 [195191.944012] hardirqs last disabled at (8688): [<ffffffff9ca037dd>] trace_hardirqs_off_thunk+0x1a/0x1c [195191.944018] softirqs last enabled at (8638): [<ffffffff9cc0a5d1>] __set_page_dirty_nobuffers+0x101/0x150 [195191.944020] softirqs last disabled at (8634): [<ffffffff9cc26bbe>] wb_wakeup_delayed+0x2e/0x60 [195191.944022] ---[ end trace 5d6e873a9a0b811a ]--- This happens because the inode does not have the flag I_LINKABLE set, which is a runtime only flag, not meant to be persisted, set when the inode is created through open(2) if the flag O_EXCL is not passed to it. Except for the warning, there are no other consequences (like corruptions or metadata inconsistencies). Since it's pointless to replay a tmpfile as it would be deleted in a later phase of the log replay procedure (it has a link count of 0), fix this by not logging tmpfiles and if a tmpfile is found in a log (created by a kernel without this change), skip the replay of the inode. A test case for fstests follows soon. Fixes: 471d557afed1 ("Btrfs: fix loss of prealloc extents past i_size after fsync log replay") CC: stable@vger.kernel.org # 4.18+ Reported-by: Martin Steigerwald <martin@lichtvoll.de> Link: https://lore.kernel.org/linux-btrfs/3666619.NTnn27ZJZE@merkaba/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-10-08 10:12:55 +00:00
/*
* Skip already logged inodes or inodes corresponding to tmpfiles
* (since logging them is pointless, a link count of 0 means they
* will never be accessible).
*/
if (btrfs_inode_in_log(inode, trans->transid) ||
inode->vfs_inode.i_nlink == 0) {
ret = BTRFS_NO_LOG_SYNC;
goto end_no_trans;
}
ret = start_log_trans(trans, root, ctx);
if (ret)
goto end_no_trans;
ret = btrfs_log_inode(trans, root, inode, inode_only, start, end, ctx);
if (ret)
goto end_trans;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* for regular files, if its inode is already on disk, we don't
* have to worry about the parents at all. This is because
* we can use the last_unlink_trans field to record renames
* and other fun in this file.
*/
if (S_ISREG(inode->vfs_inode.i_mode) &&
inode->generation <= last_committed &&
inode->last_unlink_trans <= last_committed) {
ret = 0;
goto end_trans;
}
if (S_ISDIR(inode->vfs_inode.i_mode) && ctx && ctx->log_new_dentries)
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
log_dentries = true;
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
/*
* On unlink we must make sure all our current and old parent directory
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
* inodes are fully logged. This is to prevent leaving dangling
* directory index entries in directories that were our parents but are
* not anymore. Not doing this results in old parent directory being
* impossible to delete after log replay (rmdir will always fail with
* error -ENOTEMPTY).
*
* Example 1:
*
* mkdir testdir
* touch testdir/foo
* ln testdir/foo testdir/bar
* sync
* unlink testdir/bar
* xfs_io -c fsync testdir/foo
* <power failure>
* mount fs, triggers log replay
*
* If we don't log the parent directory (testdir), after log replay the
* directory still has an entry pointing to the file inode using the bar
* name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
* the file inode has a link count of 1.
*
* Example 2:
*
* mkdir testdir
* touch foo
* ln foo testdir/foo2
* ln foo testdir/foo3
* sync
* unlink testdir/foo3
* xfs_io -c fsync foo
* <power failure>
* mount fs, triggers log replay
*
* Similar as the first example, after log replay the parent directory
* testdir still has an entry pointing to the inode file with name foo3
* but the file inode does not have a matching BTRFS_INODE_REF_KEY item
* and has a link count of 2.
*/
if (inode->last_unlink_trans > last_committed) {
ret = btrfs_log_all_parents(trans, inode, ctx);
Btrfs: fix stale dir entries after removing a link and fsync We have one more case where after a log tree is replayed we get inconsistent metadata leading to stale directory entries, due to some directories having entries pointing to some inode while the inode does not have a matching BTRFS_INODE_[REF|EXTREF]_KEY item. To trigger the problem we need to have a file with multiple hard links belonging to different parent directories. Then if one of those hard links is removed and we fsync the file using one of its other links that belongs to a different parent directory, we end up not logging the fact that the removed hard link doesn't exists anymore in the parent directory. Simple reproducer: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs generic _supported_os Linux _require_scratch _require_dm_flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test directory and file. mkdir $SCRATCH_MNT/testdir touch $SCRATCH_MNT/foo ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo2 ln $SCRATCH_MNT/foo $SCRATCH_MNT/testdir/foo3 # Make sure everything done so far is durably persisted. sync # Now we remove one of our file's hardlinks in the directory testdir. unlink $SCRATCH_MNT/testdir/foo3 # We now fsync our file using the "foo" link, which has a parent that # is not the directory "testdir". $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo # Silently drop all writes and unmount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger journal/log replay. _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # After the journal/log is replayed we expect to not see the "foo3" # link anymore and we should be able to remove all names in the # directory "testdir" and then remove it (no stale directory entries # left after the journal/log replay). echo "Entries in testdir:" ls -1 $SCRATCH_MNT/testdir rm -f $SCRATCH_MNT/testdir/* rmdir $SCRATCH_MNT/testdir _unmount_flakey status=0 exit The test fails with: $ ./check generic/107 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian3 4.1.0-rc6-btrfs-next-11+ MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/107 3s ... - output mismatch (see .../results/generic/107.out.bad) --- tests/generic/107.out 2015-08-01 01:39:45.807462161 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/107.out.bad @@ -1,3 +1,5 @@ QA output created by 107 Entries in testdir: foo2 +foo3 +rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/testdir': Directory not empty ... _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent \ (see /home/fdmanana/git/hub/xfstests/results//generic/107.full) _check_dmesg: something found in dmesg (see .../results/generic/107.dmesg) Ran: generic/107 Failures: generic/107 Failed 1 of 1 tests $ cat /home/fdmanana/git/hub/xfstests/results//generic/107.full (...) checking fs roots root 5 inode 257 errors 200, dir isize wrong unresolved ref dir 257 index 3 namelen 4 name foo3 filetype 1 errors 5, no dir item, no inode ref (...) And produces the following warning in dmesg: [127298.759064] BTRFS info (device dm-0): failed to delete reference to foo3, inode 258 parent 257 [127298.762081] ------------[ cut here ]------------ [127298.763311] WARNING: CPU: 10 PID: 7891 at fs/btrfs/inode.c:3956 __btrfs_unlink_inode+0x182/0x35a [btrfs]() [127298.767327] BTRFS: Transaction aborted (error -2) (...) [127298.788611] Call Trace: [127298.789137] [<ffffffff8145f077>] dump_stack+0x4f/0x7b [127298.790090] [<ffffffff81095de5>] ? console_unlock+0x356/0x3a2 [127298.791157] [<ffffffff8104b3b0>] warn_slowpath_common+0xa1/0xbb [127298.792323] [<ffffffffa065ad09>] ? __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.793633] [<ffffffff8104b410>] warn_slowpath_fmt+0x46/0x48 [127298.794699] [<ffffffffa065ad09>] __btrfs_unlink_inode+0x182/0x35a [btrfs] [127298.797640] [<ffffffffa065be8f>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [127298.798876] [<ffffffffa065bf11>] btrfs_unlink+0x60/0x9b [btrfs] [127298.800154] [<ffffffff8116fb48>] vfs_unlink+0x9c/0xed [127298.801303] [<ffffffff81173481>] do_unlinkat+0x12b/0x1fb [127298.802450] [<ffffffff81253855>] ? lockdep_sys_exit_thunk+0x12/0x14 [127298.803797] [<ffffffff81174056>] SyS_unlinkat+0x29/0x2b [127298.805017] [<ffffffff81465197>] system_call_fastpath+0x12/0x6f [127298.806310] ---[ end trace bbfddacb7aaada7b ]--- [127298.807325] BTRFS warning (device dm-0): __btrfs_unlink_inode:3956: Aborting unused transaction(No such entry). So fix this by logging all parent inodes, current and old ones, to make sure we do not get stale entries after log replay. This is not a simple solution such as triggering a full transaction commit because it would imply full transaction commit when an inode is fsynced in the same transaction that modified it and reloaded it after eviction (because its last_unlink_trans is set to the same value as its last_trans as of the commit with the title "Btrfs: fix stale dir entries after unlink, inode eviction and fsync"), and it would also make fstest generic/066 fail since one of the fsyncs triggers a full commit and the next fsync will not find the inode in the log anymore (therefore not removing the xattr). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-08-05 15:49:08 +00:00
if (ret)
goto end_trans;
}
ret = log_all_new_ancestors(trans, inode, parent, ctx);
if (ret)
Btrfs: fix fsync of files with multiple hard links in new directories The log tree has a long standing problem that when a file is fsync'ed we only check for new ancestors, created in the current transaction, by following only the hard link for which the fsync was issued. We follow the ancestors using the VFS' dget_parent() API. This means that if we create a new link for a file in a directory that is new (or in an any other new ancestor directory) and then fsync the file using an old hard link, we end up not logging the new ancestor, and on log replay that new hard link and ancestor do not exist. In some cases, involving renames, the file will not exist at all. Example: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt mkdir /mnt/A touch /mnt/foo ln /mnt/foo /mnt/A/bar xfs_io -c fsync /mnt/foo <power failure> In this example after log replay only the hard link named 'foo' exists and directory A does not exist, which is unexpected. In other major linux filesystems, such as ext4, xfs and f2fs for example, both hard links exist and so does directory A after mounting again the filesystem. Checking if any new ancestors are new and need to be logged was added in 2009 by commit 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes"), however only for the ancestors of the hard link (dentry) for which the fsync was issued, instead of checking for all ancestors for all of the inode's hard links. So fix this by tracking the id of the last transaction where a hard link was created for an inode and then on fsync fallback to a full transaction commit when an inode has more than one hard link and at least one new hard link was created in the current transaction. This is the simplest solution since this is not a common use case (adding frequently hard links for which there's an ancestor created in the current transaction and then fsync the file). In case it ever becomes a common use case, a solution that consists of iterating the fs/subvol btree for each hard link and check if any ancestor is new, could be implemented. This solves many unexpected scenarios reported by Jayashree Mohan and Vijay Chidambaram, and for which there is a new test case for fstests under review. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Reported-by: Jayashree Mohan <jayashree2912@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-11-28 14:54:28 +00:00
goto end_trans;
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
if (log_dentries)
ret = log_new_dir_dentries(trans, root, inode, ctx);
Btrfs: fix metadata inconsistencies after directory fsync We can get into inconsistency between inodes and directory entries after fsyncing a directory. The issue is that while a directory gets the new dentries persisted in the fsync log and replayed at mount time, the link count of the inode that directory entries point to doesn't get updated, staying with an incorrect link count (smaller then the correct value). This later leads to stale file handle errors when accessing (including attempt to delete) some of the links if all the other ones are removed, which also implies impossibility to delete the parent directories, since the dentries can not be removed. Another issue is that (unlike ext3/4, xfs, f2fs, reiserfs, nilfs2), when fsyncing a directory, new files aren't logged (their metadata and dentries) nor any child directories. So this patch fixes this issue too, since it has the same resolution as the incorrect inode link count issue mentioned before. This is very easy to reproduce, and the following excerpt from my test case for xfstests shows how: _scratch_mkfs >> $seqres.full 2>&1 _init_flakey _mount_flakey # Create our main test file and directory. $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io mkdir $SCRATCH_MNT/mydir # Make sure all metadata and data are durably persisted. sync # Add a hard link to 'foo' inside our test directory and fsync only the # directory. The btrfs fsync implementation had a bug that caused the new # directory entry to be visible after the fsync log replay but, the inode # of our file remained with a link count of 1. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2 # Add a few more links and new files. # This is just to verify nothing breaks or gives incorrect results after the # fsync log is replayed. ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3 $XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2 # Add some subdirectories and new files and links to them. This is to verify # that after fsyncing our top level directory 'mydir', all the subdirectories # and their files/links are registered in the fsync log and exist after the # fsync log is replayed. mkdir -p $SCRATCH_MNT/mydir/x/y/z ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link touch $SCRATCH_MNT/mydir/x/y/z/qwerty # Now fsync only our top directory. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir # And fsync now our new file named 'hello', just to verify later that it has # the expected content and that the previous fsync on the directory 'mydir' had # no bad influence on this fsync. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/hello # Simulate a crash/power loss. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey # Verify the content of our file 'foo' remains the same as before, 8192 bytes, # all with the value 0xaa. echo "File 'foo' content after log replay:" od -t x1 $SCRATCH_MNT/foo # Remove the first name of our inode. Because of the directory fsync bug, the # inode's link count was 1 instead of 5, so removing the 'foo' name ended up # deleting the inode and the other names became stale directory entries (still # visible to applications). Attempting to remove or access the remaining # dentries pointing to that inode resulted in stale file handle errors and # made it impossible to remove the parent directories since it was impossible # for them to become empty. echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)" rm -f $SCRATCH_MNT/foo # Now verify that all files, links and directories created before fsyncing our # directory exist after the fsync log was replayed. [ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing" [ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing" [ -f $SCRATCH_MNT/hello ] || echo "File hello is missing" [ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing" [ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \ echo "Link mydir/x/y/foo_y_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \ echo "Link mydir/x/y/z/foo_z_link is missing" [ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \ echo "File mydir/x/y/z/qwerty is missing" # We expect our file here to have a size of 64Kb and all the bytes having the # value 0xff. echo "file 'hello' content after log replay:" od -t x1 $SCRATCH_MNT/hello # Now remove all files/links, under our test directory 'mydir', and verify we # can remove all the directories. rm -f $SCRATCH_MNT/mydir/x/y/z/* rmdir $SCRATCH_MNT/mydir/x/y/z rm -f $SCRATCH_MNT/mydir/x/y/* rmdir $SCRATCH_MNT/mydir/x/y rmdir $SCRATCH_MNT/mydir/x rm -f $SCRATCH_MNT/mydir/* rmdir $SCRATCH_MNT/mydir # An fsck, run by the fstests framework everytime a test finishes, also detected # the inconsistency and printed the following error message: # # root 5 inode 257 errors 2001, no inode item, link count wrong # unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref # unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref status=0 exit The expected golden output for the test is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 5 file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 Which is the output after this patch and when running the test against ext3/4, xfs, f2fs, reiserfs or nilfs2. Without this patch, the test's output is: wrote 8192/8192 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) wrote 65536/65536 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) File 'foo' content after log replay: 0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa * 0020000 file 'foo' link count after log replay: 1 Link mydir/foo_2 is missing Link mydir/foo_3 is missing Link mydir/x/y/foo_y_link is missing Link mydir/x/y/z/foo_z_link is missing File mydir/x/y/z/qwerty is missing file 'hello' content after log replay: 0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff * 0200000 rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y/z': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x/y': No such file or directory rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/x': No such file or directory rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_2': Stale file handle rm: cannot remove '/home/fdmanana/btrfs-tests/scratch_1/mydir/foo_3': Stale file handle rmdir: failed to remove '/home/fdmanana/btrfs-tests/scratch_1/mydir': Directory not empty Fsck, without this fix, also complains about the wrong link count: root 5 inode 257 errors 2001, no inode item, link count wrong unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref So fix this by logging the inodes that the dentries point to when fsyncing a directory. A test case for xfstests follows. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-20 17:19:46 +00:00
else
ret = 0;
end_trans:
if (ret < 0) {
btrfs_set_log_full_commit(trans);
ret = 1;
}
if (ret)
btrfs_remove_log_ctx(root, ctx);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
btrfs_end_log_trans(root);
end_no_trans:
return ret;
}
/*
* it is not safe to log dentry if the chunk root has added new
* chunks. This returns 0 if the dentry was logged, and 1 otherwise.
* If this returns 1, you must commit the transaction to safely get your
* data on disk.
*/
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct dentry *dentry,
const loff_t start,
const loff_t end,
struct btrfs_log_ctx *ctx)
{
struct dentry *parent = dget_parent(dentry);
int ret;
ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
start, end, LOG_INODE_ALL, ctx);
dput(parent);
return ret;
}
/*
* should be called during mount to recover any replay any log trees
* from the FS
*/
int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
{
int ret;
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_key tmp_key;
struct btrfs_root *log;
struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
struct walk_control wc = {
.process_func = process_one_buffer,
.stage = LOG_WALK_PIN_ONLY,
};
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
trans = btrfs_start_transaction(fs_info->tree_root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto error;
}
wc.trans = trans;
wc.pin = 1;
ret = walk_log_tree(trans, log_root_tree, &wc);
if (ret) {
btrfs_handle_fs_error(fs_info, ret,
"Failed to pin buffers while recovering log root tree.");
goto error;
}
again:
key.objectid = BTRFS_TREE_LOG_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_ROOT_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
if (ret < 0) {
btrfs_handle_fs_error(fs_info, ret,
"Couldn't find tree log root.");
goto error;
}
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
btrfs_release_path(path);
if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
break;
log = btrfs_read_fs_root(log_root_tree, &found_key);
if (IS_ERR(log)) {
ret = PTR_ERR(log);
btrfs_handle_fs_error(fs_info, ret,
"Couldn't read tree log root.");
goto error;
}
tmp_key.objectid = found_key.offset;
tmp_key.type = BTRFS_ROOT_ITEM_KEY;
tmp_key.offset = (u64)-1;
wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
if (IS_ERR(wc.replay_dest)) {
ret = PTR_ERR(wc.replay_dest);
free_extent_buffer(log->node);
free_extent_buffer(log->commit_root);
kfree(log);
btrfs_handle_fs_error(fs_info, ret,
"Couldn't read target root for tree log recovery.");
goto error;
}
wc.replay_dest->log_root = log;
Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE) This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 14:45:14 +00:00
btrfs_record_root_in_trans(trans, wc.replay_dest);
ret = walk_log_tree(trans, log, &wc);
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
ret = fixup_inode_link_counts(trans, wc.replay_dest,
path);
}
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
struct btrfs_root *root = wc.replay_dest;
btrfs_release_path(path);
/*
* We have just replayed everything, and the highest
* objectid of fs roots probably has changed in case
* some inode_item's got replayed.
*
* root->objectid_mutex is not acquired as log replay
* could only happen during mount.
*/
ret = btrfs_find_highest_objectid(root,
&root->highest_objectid);
}
key.offset = found_key.offset - 1;
wc.replay_dest->log_root = NULL;
free_extent_buffer(log->node);
free_extent_buffer(log->commit_root);
kfree(log);
if (ret)
goto error;
if (found_key.offset == 0)
break;
}
btrfs_release_path(path);
/* step one is to pin it all, step two is to replay just inodes */
if (wc.pin) {
wc.pin = 0;
wc.process_func = replay_one_buffer;
wc.stage = LOG_WALK_REPLAY_INODES;
goto again;
}
/* step three is to replay everything */
if (wc.stage < LOG_WALK_REPLAY_ALL) {
wc.stage++;
goto again;
}
btrfs_free_path(path);
/* step 4: commit the transaction, which also unpins the blocks */
ret = btrfs_commit_transaction(trans);
if (ret)
return ret;
free_extent_buffer(log_root_tree->node);
log_root_tree->log_root = NULL;
clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
kfree(log_root_tree);
return 0;
error:
if (wc.trans)
btrfs_end_transaction(wc.trans);
btrfs_free_path(path);
return ret;
}
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* there are some corner cases where we want to force a full
* commit instead of allowing a directory to be logged.
*
* They revolve around files there were unlinked from the directory, and
* this function updates the parent directory so that a full commit is
* properly done if it is fsync'd later after the unlinks are done.
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
*
* Must be called before the unlink operations (updates to the subvolume tree,
* inodes, etc) are done.
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
*/
void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
int for_rename)
{
/*
* when we're logging a file, if it hasn't been renamed
* or unlinked, and its inode is fully committed on disk,
* we don't have to worry about walking up the directory chain
* to log its parents.
*
* So, we use the last_unlink_trans field to put this transid
* into the file. When the file is logged we check it and
* don't log the parents if the file is fully on disk.
*/
mutex_lock(&inode->log_mutex);
inode->last_unlink_trans = trans->transid;
mutex_unlock(&inode->log_mutex);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* if this directory was already logged any new
* names for this file/dir will get recorded
*/
if (dir->logged_trans == trans->transid)
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
return;
/*
* if the inode we're about to unlink was logged,
* the log will be properly updated for any new names
*/
if (inode->logged_trans == trans->transid)
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
return;
/*
* when renaming files across directories, if the directory
* there we're unlinking from gets fsync'd later on, there's
* no way to find the destination directory later and fsync it
* properly. So, we have to be conservative and force commits
* so the new name gets discovered.
*/
if (for_rename)
goto record;
/* we can safely do the unlink without any special recording */
return;
record:
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
Btrfs: fix unreplayable log after snapshot delete + parent dir fsync If we delete a snapshot, fsync its parent directory and crash/power fail before the next transaction commit, on the next mount when we attempt to replay the log tree of the root containing the parent directory we will fail and prevent the filesystem from mounting, which is solvable by wiping out the log trees with the btrfs-zero-log tool but very inconvenient as we will lose any data and metadata fsynced before the parent directory was fsynced. For example: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/testdir $ btrfs subvolume snapshot /mnt /mnt/testdir/snap $ btrfs subvolume delete /mnt/testdir/snap $ xfs_io -c "fsync" /mnt/testdir < crash / power failure and reboot > $ mount /dev/sdc /mnt mount: mount(2) failed: No such file or directory And in dmesg/syslog we get the following message and trace: [192066.361162] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [192066.363010] ------------[ cut here ]------------ [192066.365268] WARNING: CPU: 4 PID: 5130 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x17a/0x354 [btrfs]() [192066.367250] BTRFS: Transaction aborted (error -2) [192066.368401] Modules linked in: btrfs dm_flakey dm_mod ppdev sha256_generic xor raid6_pq hmac drbg ansi_cprng aesni_intel acpi_cpufreq tpm_tis aes_x86_64 tpm ablk_helper evdev cryptd sg parport_pc i2c_piix4 psmouse lrw parport i2c_core pcspkr gf128mul processor serio_raw glue_helper button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [192066.377154] CPU: 4 PID: 5130 Comm: mount Tainted: G W 4.4.0-rc6-btrfs-next-20+ #1 [192066.378875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [192066.380889] 0000000000000000 ffff880143923670 ffffffff81257570 ffff8801439236b8 [192066.382561] ffff8801439236a8 ffffffff8104ec07 ffffffffa039dc2c 00000000fffffffe [192066.384191] ffff8801ed31d000 ffff8801b9fc9c88 ffff8801086875e0 ffff880143923710 [192066.385827] Call Trace: [192066.386373] [<ffffffff81257570>] dump_stack+0x4e/0x79 [192066.387387] [<ffffffff8104ec07>] warn_slowpath_common+0x99/0xb2 [192066.388429] [<ffffffffa039dc2c>] ? __btrfs_unlink_inode+0x17a/0x354 [btrfs] [192066.389236] [<ffffffff8104ec68>] warn_slowpath_fmt+0x48/0x50 [192066.389884] [<ffffffffa039dc2c>] __btrfs_unlink_inode+0x17a/0x354 [btrfs] [192066.390621] [<ffffffff81184b55>] ? iput+0xb0/0x266 [192066.391200] [<ffffffffa039ea25>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [192066.391930] [<ffffffffa03ca623>] check_item_in_log+0x1fe/0x29b [btrfs] [192066.392715] [<ffffffffa03ca827>] replay_dir_deletes+0x167/0x1cf [btrfs] [192066.393510] [<ffffffffa03cccc7>] replay_one_buffer+0x417/0x570 [btrfs] [192066.394241] [<ffffffffa03ca164>] walk_up_log_tree+0x10e/0x1dc [btrfs] [192066.394958] [<ffffffffa03cac72>] walk_log_tree+0xa5/0x190 [btrfs] [192066.395628] [<ffffffffa03ce8b8>] btrfs_recover_log_trees+0x239/0x32c [btrfs] [192066.396790] [<ffffffffa03cc8b0>] ? replay_one_extent+0x50a/0x50a [btrfs] [192066.397891] [<ffffffffa0394041>] open_ctree+0x1d8b/0x2167 [btrfs] [192066.398897] [<ffffffffa03706e1>] btrfs_mount+0x5ef/0x729 [btrfs] [192066.399823] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf [192066.400739] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3 [192066.401700] [<ffffffff811714b9>] mount_fs+0x67/0x131 [192066.402482] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde [192066.403930] [<ffffffffa03702bd>] btrfs_mount+0x1cb/0x729 [btrfs] [192066.404831] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf [192066.405726] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3 [192066.406621] [<ffffffff811714b9>] mount_fs+0x67/0x131 [192066.407401] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde [192066.408247] [<ffffffff8118ae36>] do_mount+0x893/0x9d2 [192066.409047] [<ffffffff8113009b>] ? strndup_user+0x3f/0x8c [192066.409842] [<ffffffff8118b187>] SyS_mount+0x75/0xa1 [192066.410621] [<ffffffff8147e517>] entry_SYSCALL_64_fastpath+0x12/0x6b [192066.411572] ---[ end trace 2de42126c1e0a0f0 ]--- [192066.412344] BTRFS: error (device dm-0) in __btrfs_unlink_inode:3986: errno=-2 No such entry [192066.413748] BTRFS: error (device dm-0) in btrfs_replay_log:2464: errno=-2 No such entry (Failed to recover log tree) [192066.415458] BTRFS error (device dm-0): cleaner transaction attach returned -30 [192066.444613] BTRFS: open_ctree failed This happens because when we are replaying the log and processing the directory entry pointing to the snapshot in the subvolume tree, we treat its btrfs_dir_item item as having a location with a key type matching BTRFS_INODE_ITEM_KEY, which is wrong because the type matches BTRFS_ROOT_ITEM_KEY and therefore must be processed differently, as the object id refers to a root number and not to an inode in the root containing the parent directory. So fix this by triggering a transaction commit if an fsync against the parent directory is requested after deleting a snapshot. This is the simplest approach for a rare use case. Some alternative that avoids the transaction commit would require more code to explicitly delete the snapshot at log replay time (factoring out common code from ioctl.c: btrfs_ioctl_snap_destroy()), special care at fsync time to remove the log tree of the snapshot's root from the log root of the root of tree roots, amongst other steps. A test case for xfstests that triggers the issue follows. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_target flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create a snapshot at the root of our filesystem (mount point path), delete it, # fsync the mount point path, crash and mount to replay the log. This should # succeed and after the filesystem is mounted the snapshot should not be visible # anymore. _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap1 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT _flakey_drop_and_remount [ -e $SCRATCH_MNT/snap1 ] && \ echo "Snapshot snap1 still exists after log replay" # Similar scenario as above, but this time the snapshot is created inside a # directory and not directly under the root (mount point path). mkdir $SCRATCH_MNT/testdir _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/testdir/snap2 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/testdir/snap2 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir _flakey_drop_and_remount [ -e $SCRATCH_MNT/testdir/snap2 ] && \ echo "Snapshot snap2 still exists after log replay" _unmount_flakey echo "Silence is golden" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-10 10:42:25 +00:00
}
/*
* Make sure that if someone attempts to fsync the parent directory of a deleted
* snapshot, it ends up triggering a transaction commit. This is to guarantee
* that after replaying the log tree of the parent directory's root we will not
* see the snapshot anymore and at log replay time we will not see any log tree
* corresponding to the deleted snapshot's root, which could lead to replaying
* it after replaying the log tree of the parent directory (which would replay
* the snapshot delete operation).
Btrfs: fix file loss on log replay after renaming a file and fsync We have two cases where we end up deleting a file at log replay time when we should not. For this to happen the file must have been renamed and a directory inode must have been fsynced/logged. Two examples that exercise these two cases are listed below. Case 1) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/c $ touch /mnt/a/b/foo $ sync $ mv /mnt/a/b/foo /mnt/c/ # Create file bar just to make sure the fsync on directory a/ does # something and it's not a no-op. $ touch /mnt/a/bar $ xfs_io -c "fsync" /mnt/a < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file foo. Case 2) $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/foo $ ln /mnt/a/foo /mnt/b/foo_link $ touch /mnt/b/bar $ sync $ unlink /mnt/b/foo_link $ mv /mnt/b/bar /mnt/c/ $ xfs_io -c "fsync" /mnt/a/foo < power fail / crash > The next time the filesystem is mounted, the log replay procedure deletes file bar. The reason why the files are deleted is because when we log inodes other then the fsync target inode, we ignore their last_unlink_trans value and leave the log without enough information to later replay the rename operations. So we need to look at the last_unlink_trans values and fallback to a transaction commit if they are greater than the id of the last committed transaction. So fix this by looking at the last_unlink_trans values and fallback to transaction commits when needed. Also, when logging other inodes (for case 1 we logged descendants of the fsync target inode while for case 2 we logged ascendants) we need to care about concurrent tasks updating the last_unlink_trans of inodes we are logging (which was already an existing problem in check_parent_dirs_for_sync()). Since we can not acquire their inode mutex (vfs' struct inode ->i_mutex), as that causes deadlocks with other concurrent operations that acquire the i_mutex of 2 inodes (other fsyncs or renames for example), we need to serialize on the log_mutex of the inode we are logging. A task setting a new value for an inode's last_unlink_trans must acquire the inode's log_mutex and it must do this update before doing the actual unlink operation (which is already the case except when deleting a snapshot). Conversely the task logging the inode must first log the inode and then check the inode's last_unlink_trans value while holding its log_mutex, as if its value is not greater then the id of the last committed transaction it means it logged a safe state of the inode's items, while if its value is not smaller then the id of the last committed transaction it means the inode state it has logged might not be safe (the concurrent task might have just updated last_unlink_trans but hasn't done yet the unlink operation) and therefore a transaction commit must be done. Test cases for xfstests follow in separate patches. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-12 11:34:23 +00:00
*
* Must be called before the actual snapshot destroy operation (updates to the
* parent root and tree of tree roots trees, etc) are done.
Btrfs: fix unreplayable log after snapshot delete + parent dir fsync If we delete a snapshot, fsync its parent directory and crash/power fail before the next transaction commit, on the next mount when we attempt to replay the log tree of the root containing the parent directory we will fail and prevent the filesystem from mounting, which is solvable by wiping out the log trees with the btrfs-zero-log tool but very inconvenient as we will lose any data and metadata fsynced before the parent directory was fsynced. For example: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/testdir $ btrfs subvolume snapshot /mnt /mnt/testdir/snap $ btrfs subvolume delete /mnt/testdir/snap $ xfs_io -c "fsync" /mnt/testdir < crash / power failure and reboot > $ mount /dev/sdc /mnt mount: mount(2) failed: No such file or directory And in dmesg/syslog we get the following message and trace: [192066.361162] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [192066.363010] ------------[ cut here ]------------ [192066.365268] WARNING: CPU: 4 PID: 5130 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x17a/0x354 [btrfs]() [192066.367250] BTRFS: Transaction aborted (error -2) [192066.368401] Modules linked in: btrfs dm_flakey dm_mod ppdev sha256_generic xor raid6_pq hmac drbg ansi_cprng aesni_intel acpi_cpufreq tpm_tis aes_x86_64 tpm ablk_helper evdev cryptd sg parport_pc i2c_piix4 psmouse lrw parport i2c_core pcspkr gf128mul processor serio_raw glue_helper button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [192066.377154] CPU: 4 PID: 5130 Comm: mount Tainted: G W 4.4.0-rc6-btrfs-next-20+ #1 [192066.378875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [192066.380889] 0000000000000000 ffff880143923670 ffffffff81257570 ffff8801439236b8 [192066.382561] ffff8801439236a8 ffffffff8104ec07 ffffffffa039dc2c 00000000fffffffe [192066.384191] ffff8801ed31d000 ffff8801b9fc9c88 ffff8801086875e0 ffff880143923710 [192066.385827] Call Trace: [192066.386373] [<ffffffff81257570>] dump_stack+0x4e/0x79 [192066.387387] [<ffffffff8104ec07>] warn_slowpath_common+0x99/0xb2 [192066.388429] [<ffffffffa039dc2c>] ? __btrfs_unlink_inode+0x17a/0x354 [btrfs] [192066.389236] [<ffffffff8104ec68>] warn_slowpath_fmt+0x48/0x50 [192066.389884] [<ffffffffa039dc2c>] __btrfs_unlink_inode+0x17a/0x354 [btrfs] [192066.390621] [<ffffffff81184b55>] ? iput+0xb0/0x266 [192066.391200] [<ffffffffa039ea25>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [192066.391930] [<ffffffffa03ca623>] check_item_in_log+0x1fe/0x29b [btrfs] [192066.392715] [<ffffffffa03ca827>] replay_dir_deletes+0x167/0x1cf [btrfs] [192066.393510] [<ffffffffa03cccc7>] replay_one_buffer+0x417/0x570 [btrfs] [192066.394241] [<ffffffffa03ca164>] walk_up_log_tree+0x10e/0x1dc [btrfs] [192066.394958] [<ffffffffa03cac72>] walk_log_tree+0xa5/0x190 [btrfs] [192066.395628] [<ffffffffa03ce8b8>] btrfs_recover_log_trees+0x239/0x32c [btrfs] [192066.396790] [<ffffffffa03cc8b0>] ? replay_one_extent+0x50a/0x50a [btrfs] [192066.397891] [<ffffffffa0394041>] open_ctree+0x1d8b/0x2167 [btrfs] [192066.398897] [<ffffffffa03706e1>] btrfs_mount+0x5ef/0x729 [btrfs] [192066.399823] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf [192066.400739] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3 [192066.401700] [<ffffffff811714b9>] mount_fs+0x67/0x131 [192066.402482] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde [192066.403930] [<ffffffffa03702bd>] btrfs_mount+0x1cb/0x729 [btrfs] [192066.404831] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf [192066.405726] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3 [192066.406621] [<ffffffff811714b9>] mount_fs+0x67/0x131 [192066.407401] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde [192066.408247] [<ffffffff8118ae36>] do_mount+0x893/0x9d2 [192066.409047] [<ffffffff8113009b>] ? strndup_user+0x3f/0x8c [192066.409842] [<ffffffff8118b187>] SyS_mount+0x75/0xa1 [192066.410621] [<ffffffff8147e517>] entry_SYSCALL_64_fastpath+0x12/0x6b [192066.411572] ---[ end trace 2de42126c1e0a0f0 ]--- [192066.412344] BTRFS: error (device dm-0) in __btrfs_unlink_inode:3986: errno=-2 No such entry [192066.413748] BTRFS: error (device dm-0) in btrfs_replay_log:2464: errno=-2 No such entry (Failed to recover log tree) [192066.415458] BTRFS error (device dm-0): cleaner transaction attach returned -30 [192066.444613] BTRFS: open_ctree failed This happens because when we are replaying the log and processing the directory entry pointing to the snapshot in the subvolume tree, we treat its btrfs_dir_item item as having a location with a key type matching BTRFS_INODE_ITEM_KEY, which is wrong because the type matches BTRFS_ROOT_ITEM_KEY and therefore must be processed differently, as the object id refers to a root number and not to an inode in the root containing the parent directory. So fix this by triggering a transaction commit if an fsync against the parent directory is requested after deleting a snapshot. This is the simplest approach for a rare use case. Some alternative that avoids the transaction commit would require more code to explicitly delete the snapshot at log replay time (factoring out common code from ioctl.c: btrfs_ioctl_snap_destroy()), special care at fsync time to remove the log tree of the snapshot's root from the log root of the root of tree roots, amongst other steps. A test case for xfstests that triggers the issue follows. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_target flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create a snapshot at the root of our filesystem (mount point path), delete it, # fsync the mount point path, crash and mount to replay the log. This should # succeed and after the filesystem is mounted the snapshot should not be visible # anymore. _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap1 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT _flakey_drop_and_remount [ -e $SCRATCH_MNT/snap1 ] && \ echo "Snapshot snap1 still exists after log replay" # Similar scenario as above, but this time the snapshot is created inside a # directory and not directly under the root (mount point path). mkdir $SCRATCH_MNT/testdir _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/testdir/snap2 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/testdir/snap2 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir _flakey_drop_and_remount [ -e $SCRATCH_MNT/testdir/snap2 ] && \ echo "Snapshot snap2 still exists after log replay" _unmount_flakey echo "Silence is golden" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-10 10:42:25 +00:00
*/
void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir)
Btrfs: fix unreplayable log after snapshot delete + parent dir fsync If we delete a snapshot, fsync its parent directory and crash/power fail before the next transaction commit, on the next mount when we attempt to replay the log tree of the root containing the parent directory we will fail and prevent the filesystem from mounting, which is solvable by wiping out the log trees with the btrfs-zero-log tool but very inconvenient as we will lose any data and metadata fsynced before the parent directory was fsynced. For example: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/testdir $ btrfs subvolume snapshot /mnt /mnt/testdir/snap $ btrfs subvolume delete /mnt/testdir/snap $ xfs_io -c "fsync" /mnt/testdir < crash / power failure and reboot > $ mount /dev/sdc /mnt mount: mount(2) failed: No such file or directory And in dmesg/syslog we get the following message and trace: [192066.361162] BTRFS info (device dm-0): failed to delete reference to snap, inode 257 parent 257 [192066.363010] ------------[ cut here ]------------ [192066.365268] WARNING: CPU: 4 PID: 5130 at fs/btrfs/inode.c:3986 __btrfs_unlink_inode+0x17a/0x354 [btrfs]() [192066.367250] BTRFS: Transaction aborted (error -2) [192066.368401] Modules linked in: btrfs dm_flakey dm_mod ppdev sha256_generic xor raid6_pq hmac drbg ansi_cprng aesni_intel acpi_cpufreq tpm_tis aes_x86_64 tpm ablk_helper evdev cryptd sg parport_pc i2c_piix4 psmouse lrw parport i2c_core pcspkr gf128mul processor serio_raw glue_helper button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [192066.377154] CPU: 4 PID: 5130 Comm: mount Tainted: G W 4.4.0-rc6-btrfs-next-20+ #1 [192066.378875] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [192066.380889] 0000000000000000 ffff880143923670 ffffffff81257570 ffff8801439236b8 [192066.382561] ffff8801439236a8 ffffffff8104ec07 ffffffffa039dc2c 00000000fffffffe [192066.384191] ffff8801ed31d000 ffff8801b9fc9c88 ffff8801086875e0 ffff880143923710 [192066.385827] Call Trace: [192066.386373] [<ffffffff81257570>] dump_stack+0x4e/0x79 [192066.387387] [<ffffffff8104ec07>] warn_slowpath_common+0x99/0xb2 [192066.388429] [<ffffffffa039dc2c>] ? __btrfs_unlink_inode+0x17a/0x354 [btrfs] [192066.389236] [<ffffffff8104ec68>] warn_slowpath_fmt+0x48/0x50 [192066.389884] [<ffffffffa039dc2c>] __btrfs_unlink_inode+0x17a/0x354 [btrfs] [192066.390621] [<ffffffff81184b55>] ? iput+0xb0/0x266 [192066.391200] [<ffffffffa039ea25>] btrfs_unlink_inode+0x1c/0x3d [btrfs] [192066.391930] [<ffffffffa03ca623>] check_item_in_log+0x1fe/0x29b [btrfs] [192066.392715] [<ffffffffa03ca827>] replay_dir_deletes+0x167/0x1cf [btrfs] [192066.393510] [<ffffffffa03cccc7>] replay_one_buffer+0x417/0x570 [btrfs] [192066.394241] [<ffffffffa03ca164>] walk_up_log_tree+0x10e/0x1dc [btrfs] [192066.394958] [<ffffffffa03cac72>] walk_log_tree+0xa5/0x190 [btrfs] [192066.395628] [<ffffffffa03ce8b8>] btrfs_recover_log_trees+0x239/0x32c [btrfs] [192066.396790] [<ffffffffa03cc8b0>] ? replay_one_extent+0x50a/0x50a [btrfs] [192066.397891] [<ffffffffa0394041>] open_ctree+0x1d8b/0x2167 [btrfs] [192066.398897] [<ffffffffa03706e1>] btrfs_mount+0x5ef/0x729 [btrfs] [192066.399823] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf [192066.400739] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3 [192066.401700] [<ffffffff811714b9>] mount_fs+0x67/0x131 [192066.402482] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde [192066.403930] [<ffffffffa03702bd>] btrfs_mount+0x1cb/0x729 [btrfs] [192066.404831] [<ffffffff8108ad98>] ? trace_hardirqs_on+0xd/0xf [192066.405726] [<ffffffff8108959b>] ? lockdep_init_map+0xb9/0x1b3 [192066.406621] [<ffffffff811714b9>] mount_fs+0x67/0x131 [192066.407401] [<ffffffff81188560>] vfs_kern_mount+0x6c/0xde [192066.408247] [<ffffffff8118ae36>] do_mount+0x893/0x9d2 [192066.409047] [<ffffffff8113009b>] ? strndup_user+0x3f/0x8c [192066.409842] [<ffffffff8118b187>] SyS_mount+0x75/0xa1 [192066.410621] [<ffffffff8147e517>] entry_SYSCALL_64_fastpath+0x12/0x6b [192066.411572] ---[ end trace 2de42126c1e0a0f0 ]--- [192066.412344] BTRFS: error (device dm-0) in __btrfs_unlink_inode:3986: errno=-2 No such entry [192066.413748] BTRFS: error (device dm-0) in btrfs_replay_log:2464: errno=-2 No such entry (Failed to recover log tree) [192066.415458] BTRFS error (device dm-0): cleaner transaction attach returned -30 [192066.444613] BTRFS: open_ctree failed This happens because when we are replaying the log and processing the directory entry pointing to the snapshot in the subvolume tree, we treat its btrfs_dir_item item as having a location with a key type matching BTRFS_INODE_ITEM_KEY, which is wrong because the type matches BTRFS_ROOT_ITEM_KEY and therefore must be processed differently, as the object id refers to a root number and not to an inode in the root containing the parent directory. So fix this by triggering a transaction commit if an fsync against the parent directory is requested after deleting a snapshot. This is the simplest approach for a rare use case. Some alternative that avoids the transaction commit would require more code to explicitly delete the snapshot at log replay time (factoring out common code from ioctl.c: btrfs_ioctl_snap_destroy()), special care at fsync time to remove the log tree of the snapshot's root from the log root of the root of tree roots, amongst other steps. A test case for xfstests that triggers the issue follows. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_target flakey _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create a snapshot at the root of our filesystem (mount point path), delete it, # fsync the mount point path, crash and mount to replay the log. This should # succeed and after the filesystem is mounted the snapshot should not be visible # anymore. _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap1 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap1 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT _flakey_drop_and_remount [ -e $SCRATCH_MNT/snap1 ] && \ echo "Snapshot snap1 still exists after log replay" # Similar scenario as above, but this time the snapshot is created inside a # directory and not directly under the root (mount point path). mkdir $SCRATCH_MNT/testdir _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/testdir/snap2 _run_btrfs_util_prog subvolume delete $SCRATCH_MNT/testdir/snap2 $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/testdir _flakey_drop_and_remount [ -e $SCRATCH_MNT/testdir/snap2 ] && \ echo "Snapshot snap2 still exists after log replay" _unmount_flakey echo "Silence is golden" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-10 10:42:25 +00:00
{
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
}
/*
* Call this after adding a new name for a file and it will properly
* update the log to reflect the new name.
*
Btrfs: sync log after logging new name When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-11 18:24:28 +00:00
* @ctx can not be NULL when @sync_log is false, and should be NULL when it's
* true (because it's not used).
*
* Return value depends on whether @sync_log is true or false.
* When true: returns BTRFS_NEED_TRANS_COMMIT if the transaction needs to be
* committed by the caller, and BTRFS_DONT_NEED_TRANS_COMMIT
* otherwise.
* When false: returns BTRFS_DONT_NEED_LOG_SYNC if the caller does not need to
* to sync the log, BTRFS_NEED_LOG_SYNC if it needs to sync the log,
* or BTRFS_NEED_TRANS_COMMIT if the transaction needs to be
* committed (without attempting to sync the log).
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
*/
int btrfs_log_new_name(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode, struct btrfs_inode *old_dir,
Btrfs: sync log after logging new name When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-11 18:24:28 +00:00
struct dentry *parent,
bool sync_log, struct btrfs_log_ctx *ctx)
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
{
struct btrfs_fs_info *fs_info = trans->fs_info;
Btrfs: sync log after logging new name When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-11 18:24:28 +00:00
int ret;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* this will force the logging code to walk the dentry chain
* up for the file
*/
Btrfs: fix log replay failure after linking special file and fsync If in the same transaction we rename a special file (fifo, character/block device or symbolic link), create a hard link for it having its old name then sync the log, we will end up with a log that can not be replayed and at when attempting to replay it, an EEXIST error is returned and mounting the filesystem fails. Example scenario: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/testdir $ mkfifo /mnt/testdir/foo # Make sure everything done so far is durably persisted. $ sync # Create some unrelated file and fsync it, this is just to create a log # tree. The file must be in the same directory as our special file. $ touch /mnt/testdir/f1 $ xfs_io -c "fsync" /mnt/testdir/f1 # Rename our special file and then create a hard link with its old name. $ mv /mnt/testdir/foo /mnt/testdir/bar $ ln /mnt/testdir/bar /mnt/testdir/foo # Create some other unrelated file and fsync it, this is just to persist # the log tree which was modified by the previous rename and link # operations. Alternatively we could have modified file f1 and fsync it. $ touch /mnt/f2 $ xfs_io -c "fsync" /mnt/f2 <power failure> $ mount /dev/sdc /mnt mount: mount /dev/sdc on /mnt failed: File exists This happens because when both the log tree and the subvolume's tree have an entry in the directory "testdir" with the same name, that is, there is one key (258 INODE_REF 257) in the subvolume tree and another one in the log tree (where 258 is the inode number of our special file and 257 is the inode for directory "testdir"). Only the data of those two keys differs, in the subvolume tree the index field for inode reference has a value of 3 while the log tree it has a value of 5. Because the same key exists in both trees, but have different index, the log replay fails with an -EEXIST error when attempting to replay the inode reference from the log tree. Fix this by setting the last_unlink_trans field of the inode (our special file) to the current transaction id when a hard link is created, as this forces logging the parent directory inode, solving the conflict at log replay time. A new generic test case for fstests was also submitted. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28 15:55:40 +00:00
if (!S_ISDIR(inode->vfs_inode.i_mode))
inode->last_unlink_trans = trans->transid;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
/*
* if this inode hasn't been logged and directory we're renaming it
* from hasn't been logged, we don't need to log it
*/
if (inode->logged_trans <= fs_info->last_trans_committed &&
(!old_dir || old_dir->logged_trans <= fs_info->last_trans_committed))
Btrfs: sync log after logging new name When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-11 18:24:28 +00:00
return sync_log ? BTRFS_DONT_NEED_TRANS_COMMIT :
BTRFS_DONT_NEED_LOG_SYNC;
if (sync_log) {
struct btrfs_log_ctx ctx2;
btrfs_init_log_ctx(&ctx2, &inode->vfs_inode);
ret = btrfs_log_inode_parent(trans, inode, parent, 0, LLONG_MAX,
LOG_INODE_EXISTS, &ctx2);
if (ret == BTRFS_NO_LOG_SYNC)
return BTRFS_DONT_NEED_TRANS_COMMIT;
else if (ret)
return BTRFS_NEED_TRANS_COMMIT;
ret = btrfs_sync_log(trans, inode->root, &ctx2);
if (ret)
return BTRFS_NEED_TRANS_COMMIT;
return BTRFS_DONT_NEED_TRANS_COMMIT;
}
ASSERT(ctx);
ret = btrfs_log_inode_parent(trans, inode, parent, 0, LLONG_MAX,
LOG_INODE_EXISTS, ctx);
if (ret == BTRFS_NO_LOG_SYNC)
return BTRFS_DONT_NEED_LOG_SYNC;
else if (ret)
return BTRFS_NEED_TRANS_COMMIT;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
Btrfs: sync log after logging new name When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-06-11 18:24:28 +00:00
return BTRFS_NEED_LOG_SYNC;
Btrfs: tree logging unlink/rename fixes The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24 14:24:20 +00:00
}