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linux/fs/btrfs/scrub.c
Qu Wenruo b42fe98c92 btrfs: scrub: allow scrub to work with subpage sectorsize 
Since btrfs scrub is utilizing its own infrastructure to submit
read/write, scrub is independent from all other routines.

This brings one very neat feature, allow us to read 4K data into offset
0 of a 64K page.  So is the writeback routine.

This makes scrub on subpage sector size much easier to implement, and
thanks to previous commits which just changed the implementation to
always do scrub based on sector size, now scrub can handle subpage
filesystem without any problem.

This patch will just remove the restriction on
(sectorsize != PAGE_SIZE), to make scrub finally work on subpage
filesystems.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09 19:16:11 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011, 2012 STRATO. All rights reserved.
*/
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include "ctree.h"
#include "discard.h"
#include "volumes.h"
#include "disk-io.h"
#include "ordered-data.h"
#include "transaction.h"
#include "backref.h"
#include "extent_io.h"
#include "dev-replace.h"
#include "check-integrity.h"
#include "rcu-string.h"
#include "raid56.h"
#include "block-group.h"
#include "zoned.h"
/*
* This is only the first step towards a full-features scrub. It reads all
* extent and super block and verifies the checksums. In case a bad checksum
* is found or the extent cannot be read, good data will be written back if
* any can be found.
*
* Future enhancements:
* - In case an unrepairable extent is encountered, track which files are
* affected and report them
* - track and record media errors, throw out bad devices
* - add a mode to also read unallocated space
*/
struct scrub_block;
struct scrub_ctx;
/*
* the following three values only influence the performance.
* The last one configures the number of parallel and outstanding I/O
* operations. The first two values configure an upper limit for the number
* of (dynamically allocated) pages that are added to a bio.
*/
#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
/*
* the following value times PAGE_SIZE needs to be large enough to match the
* largest node/leaf/sector size that shall be supported.
* Values larger than BTRFS_STRIPE_LEN are not supported.
*/
#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
struct scrub_recover {
refcount_t refs;
struct btrfs_bio *bbio;
u64 map_length;
};
struct scrub_page {
struct scrub_block *sblock;
struct page *page;
struct btrfs_device *dev;
struct list_head list;
u64 flags; /* extent flags */
u64 generation;
u64 logical;
u64 physical;
u64 physical_for_dev_replace;
atomic_t refs;
u8 mirror_num;
int have_csum:1;
int io_error:1;
u8 csum[BTRFS_CSUM_SIZE];
struct scrub_recover *recover;
};
struct scrub_bio {
int index;
struct scrub_ctx *sctx;
struct btrfs_device *dev;
struct bio *bio;
blk_status_t status;
u64 logical;
u64 physical;
#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
#else
struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
#endif
int page_count;
int next_free;
struct btrfs_work work;
};
struct scrub_block {
struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
int page_count;
atomic_t outstanding_pages;
refcount_t refs; /* free mem on transition to zero */
struct scrub_ctx *sctx;
struct scrub_parity *sparity;
struct {
unsigned int header_error:1;
unsigned int checksum_error:1;
unsigned int no_io_error_seen:1;
unsigned int generation_error:1; /* also sets header_error */
/* The following is for the data used to check parity */
/* It is for the data with checksum */
unsigned int data_corrected:1;
};
struct btrfs_work work;
};
/* Used for the chunks with parity stripe such RAID5/6 */
struct scrub_parity {
struct scrub_ctx *sctx;
struct btrfs_device *scrub_dev;
u64 logic_start;
u64 logic_end;
int nsectors;
u32 stripe_len;
refcount_t refs;
struct list_head spages;
/* Work of parity check and repair */
struct btrfs_work work;
/* Mark the parity blocks which have data */
unsigned long *dbitmap;
/*
* Mark the parity blocks which have data, but errors happen when
* read data or check data
*/
unsigned long *ebitmap;
unsigned long bitmap[];
};
struct scrub_ctx {
struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
struct btrfs_fs_info *fs_info;
int first_free;
int curr;
atomic_t bios_in_flight;
atomic_t workers_pending;
spinlock_t list_lock;
wait_queue_head_t list_wait;
struct list_head csum_list;
atomic_t cancel_req;
int readonly;
int pages_per_rd_bio;
int is_dev_replace;
struct scrub_bio *wr_curr_bio;
struct mutex wr_lock;
int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
struct btrfs_device *wr_tgtdev;
bool flush_all_writes;
/*
* statistics
*/
struct btrfs_scrub_progress stat;
spinlock_t stat_lock;
/*
* Use a ref counter to avoid use-after-free issues. Scrub workers
* decrement bios_in_flight and workers_pending and then do a wakeup
* on the list_wait wait queue. We must ensure the main scrub task
* doesn't free the scrub context before or while the workers are
* doing the wakeup() call.
*/
refcount_t refs;
};
struct scrub_warning {
struct btrfs_path *path;
u64 extent_item_size;
const char *errstr;
u64 physical;
u64 logical;
struct btrfs_device *dev;
};
struct full_stripe_lock {
struct rb_node node;
u64 logical;
u64 refs;
struct mutex mutex;
};
static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
struct scrub_block *sblocks_for_recheck);
static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock,
int retry_failed_mirror);
static void scrub_recheck_block_checksum(struct scrub_block *sblock);
static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good);
static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int page_num, int force_write);
static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
int page_num);
static int scrub_checksum_data(struct scrub_block *sblock);
static int scrub_checksum_tree_block(struct scrub_block *sblock);
static int scrub_checksum_super(struct scrub_block *sblock);
static void scrub_block_get(struct scrub_block *sblock);
static void scrub_block_put(struct scrub_block *sblock);
static void scrub_page_get(struct scrub_page *spage);
static void scrub_page_put(struct scrub_page *spage);
static void scrub_parity_get(struct scrub_parity *sparity);
static void scrub_parity_put(struct scrub_parity *sparity);
static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
struct scrub_page *spage);
static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u32 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u8 *csum,
u64 physical_for_dev_replace);
static void scrub_bio_end_io(struct bio *bio);
static void scrub_bio_end_io_worker(struct btrfs_work *work);
static void scrub_block_complete(struct scrub_block *sblock);
static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
u64 extent_logical, u32 extent_len,
u64 *extent_physical,
struct btrfs_device **extent_dev,
int *extent_mirror_num);
static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
struct scrub_page *spage);
static void scrub_wr_submit(struct scrub_ctx *sctx);
static void scrub_wr_bio_end_io(struct bio *bio);
static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
static void scrub_put_ctx(struct scrub_ctx *sctx);
static inline int scrub_is_page_on_raid56(struct scrub_page *spage)
{
return spage->recover &&
(spage->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
}
static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
{
refcount_inc(&sctx->refs);
atomic_inc(&sctx->bios_in_flight);
}
static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
{
atomic_dec(&sctx->bios_in_flight);
wake_up(&sctx->list_wait);
scrub_put_ctx(sctx);
}
static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
while (atomic_read(&fs_info->scrub_pause_req)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrub_pause_req) == 0);
mutex_lock(&fs_info->scrub_lock);
}
}
static void scrub_pause_on(struct btrfs_fs_info *fs_info)
{
atomic_inc(&fs_info->scrubs_paused);
wake_up(&fs_info->scrub_pause_wait);
}
static void scrub_pause_off(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
__scrub_blocked_if_needed(fs_info);
atomic_dec(&fs_info->scrubs_paused);
mutex_unlock(&fs_info->scrub_lock);
wake_up(&fs_info->scrub_pause_wait);
}
static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
{
scrub_pause_on(fs_info);
scrub_pause_off(fs_info);
}
/*
* Insert new full stripe lock into full stripe locks tree
*
* Return pointer to existing or newly inserted full_stripe_lock structure if
* everything works well.
* Return ERR_PTR(-ENOMEM) if we failed to allocate memory
*
* NOTE: caller must hold full_stripe_locks_root->lock before calling this
* function
*/
static struct full_stripe_lock *insert_full_stripe_lock(
struct btrfs_full_stripe_locks_tree *locks_root,
u64 fstripe_logical)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct full_stripe_lock *entry;
struct full_stripe_lock *ret;
lockdep_assert_held(&locks_root->lock);
p = &locks_root->root.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct full_stripe_lock, node);
if (fstripe_logical < entry->logical) {
p = &(*p)->rb_left;
} else if (fstripe_logical > entry->logical) {
p = &(*p)->rb_right;
} else {
entry->refs++;
return entry;
}
}
/*
* Insert new lock.
*/
ret = kmalloc(sizeof(*ret), GFP_KERNEL);
if (!ret)
return ERR_PTR(-ENOMEM);
ret->logical = fstripe_logical;
ret->refs = 1;
mutex_init(&ret->mutex);
rb_link_node(&ret->node, parent, p);
rb_insert_color(&ret->node, &locks_root->root);
return ret;
}
/*
* Search for a full stripe lock of a block group
*
* Return pointer to existing full stripe lock if found
* Return NULL if not found
*/
static struct full_stripe_lock *search_full_stripe_lock(
struct btrfs_full_stripe_locks_tree *locks_root,
u64 fstripe_logical)
{
struct rb_node *node;
struct full_stripe_lock *entry;
lockdep_assert_held(&locks_root->lock);
node = locks_root->root.rb_node;
while (node) {
entry = rb_entry(node, struct full_stripe_lock, node);
if (fstripe_logical < entry->logical)
node = node->rb_left;
else if (fstripe_logical > entry->logical)
node = node->rb_right;
else
return entry;
}
return NULL;
}
/*
* Helper to get full stripe logical from a normal bytenr.
*
* Caller must ensure @cache is a RAID56 block group.
*/
static u64 get_full_stripe_logical(struct btrfs_block_group *cache, u64 bytenr)
{
u64 ret;
/*
* Due to chunk item size limit, full stripe length should not be
* larger than U32_MAX. Just a sanity check here.
*/
WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
/*
* round_down() can only handle power of 2, while RAID56 full
* stripe length can be 64KiB * n, so we need to manually round down.
*/
ret = div64_u64(bytenr - cache->start, cache->full_stripe_len) *
cache->full_stripe_len + cache->start;
return ret;
}
/*
* Lock a full stripe to avoid concurrency of recovery and read
*
* It's only used for profiles with parities (RAID5/6), for other profiles it
* does nothing.
*
* Return 0 if we locked full stripe covering @bytenr, with a mutex held.
* So caller must call unlock_full_stripe() at the same context.
*
* Return <0 if encounters error.
*/
static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
bool *locked_ret)
{
struct btrfs_block_group *bg_cache;
struct btrfs_full_stripe_locks_tree *locks_root;
struct full_stripe_lock *existing;
u64 fstripe_start;
int ret = 0;
*locked_ret = false;
bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
if (!bg_cache) {
ASSERT(0);
return -ENOENT;
}
/* Profiles not based on parity don't need full stripe lock */
if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
goto out;
locks_root = &bg_cache->full_stripe_locks_root;
fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
/* Now insert the full stripe lock */
mutex_lock(&locks_root->lock);
existing = insert_full_stripe_lock(locks_root, fstripe_start);
mutex_unlock(&locks_root->lock);
if (IS_ERR(existing)) {
ret = PTR_ERR(existing);
goto out;
}
mutex_lock(&existing->mutex);
*locked_ret = true;
out:
btrfs_put_block_group(bg_cache);
return ret;
}
/*
* Unlock a full stripe.
*
* NOTE: Caller must ensure it's the same context calling corresponding
* lock_full_stripe().
*
* Return 0 if we unlock full stripe without problem.
* Return <0 for error
*/
static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
bool locked)
{
struct btrfs_block_group *bg_cache;
struct btrfs_full_stripe_locks_tree *locks_root;
struct full_stripe_lock *fstripe_lock;
u64 fstripe_start;
bool freeit = false;
int ret = 0;
/* If we didn't acquire full stripe lock, no need to continue */
if (!locked)
return 0;
bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
if (!bg_cache) {
ASSERT(0);
return -ENOENT;
}
if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
goto out;
locks_root = &bg_cache->full_stripe_locks_root;
fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
mutex_lock(&locks_root->lock);
fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
/* Unpaired unlock_full_stripe() detected */
if (!fstripe_lock) {
WARN_ON(1);
ret = -ENOENT;
mutex_unlock(&locks_root->lock);
goto out;
}
if (fstripe_lock->refs == 0) {
WARN_ON(1);
btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
fstripe_lock->logical);
} else {
fstripe_lock->refs--;
}
if (fstripe_lock->refs == 0) {
rb_erase(&fstripe_lock->node, &locks_root->root);
freeit = true;
}
mutex_unlock(&locks_root->lock);
mutex_unlock(&fstripe_lock->mutex);
if (freeit)
kfree(fstripe_lock);
out:
btrfs_put_block_group(bg_cache);
return ret;
}
static void scrub_free_csums(struct scrub_ctx *sctx)
{
while (!list_empty(&sctx->csum_list)) {
struct btrfs_ordered_sum *sum;
sum = list_first_entry(&sctx->csum_list,
struct btrfs_ordered_sum, list);
list_del(&sum->list);
kfree(sum);
}
}
static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
{
int i;
if (!sctx)
return;
/* this can happen when scrub is cancelled */
if (sctx->curr != -1) {
struct scrub_bio *sbio = sctx->bios[sctx->curr];
for (i = 0; i < sbio->page_count; i++) {
WARN_ON(!sbio->pagev[i]->page);
scrub_block_put(sbio->pagev[i]->sblock);
}
bio_put(sbio->bio);
}
for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
struct scrub_bio *sbio = sctx->bios[i];
if (!sbio)
break;
kfree(sbio);
}
kfree(sctx->wr_curr_bio);
scrub_free_csums(sctx);
kfree(sctx);
}
static void scrub_put_ctx(struct scrub_ctx *sctx)
{
if (refcount_dec_and_test(&sctx->refs))
scrub_free_ctx(sctx);
}
static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
struct btrfs_fs_info *fs_info, int is_dev_replace)
{
struct scrub_ctx *sctx;
int i;
sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
if (!sctx)
goto nomem;
refcount_set(&sctx->refs, 1);
sctx->is_dev_replace = is_dev_replace;
sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
sctx->curr = -1;
sctx->fs_info = fs_info;
INIT_LIST_HEAD(&sctx->csum_list);
for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
struct scrub_bio *sbio;
sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
if (!sbio)
goto nomem;
sctx->bios[i] = sbio;
sbio->index = i;
sbio->sctx = sctx;
sbio->page_count = 0;
btrfs_init_work(&sbio->work, scrub_bio_end_io_worker, NULL,
NULL);
if (i != SCRUB_BIOS_PER_SCTX - 1)
sctx->bios[i]->next_free = i + 1;
else
sctx->bios[i]->next_free = -1;
}
sctx->first_free = 0;
atomic_set(&sctx->bios_in_flight, 0);
atomic_set(&sctx->workers_pending, 0);
atomic_set(&sctx->cancel_req, 0);
spin_lock_init(&sctx->list_lock);
spin_lock_init(&sctx->stat_lock);
init_waitqueue_head(&sctx->list_wait);
WARN_ON(sctx->wr_curr_bio != NULL);
mutex_init(&sctx->wr_lock);
sctx->wr_curr_bio = NULL;
if (is_dev_replace) {
WARN_ON(!fs_info->dev_replace.tgtdev);
sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
sctx->flush_all_writes = false;
}
return sctx;
nomem:
scrub_free_ctx(sctx);
return ERR_PTR(-ENOMEM);
}
static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
void *warn_ctx)
{
u64 isize;
u32 nlink;
int ret;
int i;
unsigned nofs_flag;
struct extent_buffer *eb;
struct btrfs_inode_item *inode_item;
struct scrub_warning *swarn = warn_ctx;
struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
struct inode_fs_paths *ipath = NULL;
struct btrfs_root *local_root;
struct btrfs_key key;
local_root = btrfs_get_fs_root(fs_info, root, true);
if (IS_ERR(local_root)) {
ret = PTR_ERR(local_root);
goto err;
}
/*
* this makes the path point to (inum INODE_ITEM ioff)
*/
key.objectid = inum;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
if (ret) {
btrfs_put_root(local_root);
btrfs_release_path(swarn->path);
goto err;
}
eb = swarn->path->nodes[0];
inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
struct btrfs_inode_item);
isize = btrfs_inode_size(eb, inode_item);
nlink = btrfs_inode_nlink(eb, inode_item);
btrfs_release_path(swarn->path);
/*
* init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
* uses GFP_NOFS in this context, so we keep it consistent but it does
* not seem to be strictly necessary.
*/
nofs_flag = memalloc_nofs_save();
ipath = init_ipath(4096, local_root, swarn->path);
memalloc_nofs_restore(nofs_flag);
if (IS_ERR(ipath)) {
btrfs_put_root(local_root);
ret = PTR_ERR(ipath);
ipath = NULL;
goto err;
}
ret = paths_from_inode(inum, ipath);
if (ret < 0)
goto err;
/*
* we deliberately ignore the bit ipath might have been too small to
* hold all of the paths here
*/
for (i = 0; i < ipath->fspath->elem_cnt; ++i)
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %llu, links %u (path: %s)",
swarn->errstr, swarn->logical,
rcu_str_deref(swarn->dev->name),
swarn->physical,
root, inum, offset,
min(isize - offset, (u64)PAGE_SIZE), nlink,
(char *)(unsigned long)ipath->fspath->val[i]);
btrfs_put_root(local_root);
free_ipath(ipath);
return 0;
err:
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
swarn->errstr, swarn->logical,
rcu_str_deref(swarn->dev->name),
swarn->physical,
root, inum, offset, ret);
free_ipath(ipath);
return 0;
}
static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
{
struct btrfs_device *dev;
struct btrfs_fs_info *fs_info;
struct btrfs_path *path;
struct btrfs_key found_key;
struct extent_buffer *eb;
struct btrfs_extent_item *ei;
struct scrub_warning swarn;
unsigned long ptr = 0;
u64 extent_item_pos;
u64 flags = 0;
u64 ref_root;
u32 item_size;
u8 ref_level = 0;
int ret;
WARN_ON(sblock->page_count < 1);
dev = sblock->pagev[0]->dev;
fs_info = sblock->sctx->fs_info;
path = btrfs_alloc_path();
if (!path)
return;
swarn.physical = sblock->pagev[0]->physical;
swarn.logical = sblock->pagev[0]->logical;
swarn.errstr = errstr;
swarn.dev = NULL;
ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
&flags);
if (ret < 0)
goto out;
extent_item_pos = swarn.logical - found_key.objectid;
swarn.extent_item_size = found_key.offset;
eb = path->nodes[0];
ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
item_size = btrfs_item_size_nr(eb, path->slots[0]);
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
do {
ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
item_size, &ref_root,
&ref_level);
btrfs_warn_in_rcu(fs_info,
"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
errstr, swarn.logical,
rcu_str_deref(dev->name),
swarn.physical,
ref_level ? "node" : "leaf",
ret < 0 ? -1 : ref_level,
ret < 0 ? -1 : ref_root);
} while (ret != 1);
btrfs_release_path(path);
} else {
btrfs_release_path(path);
swarn.path = path;
swarn.dev = dev;
iterate_extent_inodes(fs_info, found_key.objectid,
extent_item_pos, 1,
scrub_print_warning_inode, &swarn, false);
}
out:
btrfs_free_path(path);
}
static inline void scrub_get_recover(struct scrub_recover *recover)
{
refcount_inc(&recover->refs);
}
static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
struct scrub_recover *recover)
{
if (refcount_dec_and_test(&recover->refs)) {
btrfs_bio_counter_dec(fs_info);
btrfs_put_bbio(recover->bbio);
kfree(recover);
}
}
/*
* scrub_handle_errored_block gets called when either verification of the
* pages failed or the bio failed to read, e.g. with EIO. In the latter
* case, this function handles all pages in the bio, even though only one
* may be bad.
* The goal of this function is to repair the errored block by using the
* contents of one of the mirrors.
*/
static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
{
struct scrub_ctx *sctx = sblock_to_check->sctx;
struct btrfs_device *dev;
struct btrfs_fs_info *fs_info;
u64 logical;
unsigned int failed_mirror_index;
unsigned int is_metadata;
unsigned int have_csum;
struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
struct scrub_block *sblock_bad;
int ret;
int mirror_index;
int page_num;
int success;
bool full_stripe_locked;
unsigned int nofs_flag;
static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
BUG_ON(sblock_to_check->page_count < 1);
fs_info = sctx->fs_info;
if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
/*
* if we find an error in a super block, we just report it.
* They will get written with the next transaction commit
* anyway
*/
spin_lock(&sctx->stat_lock);
++sctx->stat.super_errors;
spin_unlock(&sctx->stat_lock);
return 0;
}
logical = sblock_to_check->pagev[0]->logical;
BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
is_metadata = !(sblock_to_check->pagev[0]->flags &
BTRFS_EXTENT_FLAG_DATA);
have_csum = sblock_to_check->pagev[0]->have_csum;
dev = sblock_to_check->pagev[0]->dev;
/*
* We must use GFP_NOFS because the scrub task might be waiting for a
* worker task executing this function and in turn a transaction commit
* might be waiting the scrub task to pause (which needs to wait for all
* the worker tasks to complete before pausing).
* We do allocations in the workers through insert_full_stripe_lock()
* and scrub_add_page_to_wr_bio(), which happens down the call chain of
* this function.
*/
nofs_flag = memalloc_nofs_save();
/*
* For RAID5/6, race can happen for a different device scrub thread.
* For data corruption, Parity and Data threads will both try
* to recovery the data.
* Race can lead to doubly added csum error, or even unrecoverable
* error.
*/
ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
if (ret < 0) {
memalloc_nofs_restore(nofs_flag);
spin_lock(&sctx->stat_lock);
if (ret == -ENOMEM)
sctx->stat.malloc_errors++;
sctx->stat.read_errors++;
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
return ret;
}
/*
* read all mirrors one after the other. This includes to
* re-read the extent or metadata block that failed (that was
* the cause that this fixup code is called) another time,
* page by page this time in order to know which pages
* caused I/O errors and which ones are good (for all mirrors).
* It is the goal to handle the situation when more than one
* mirror contains I/O errors, but the errors do not
* overlap, i.e. the data can be repaired by selecting the
* pages from those mirrors without I/O error on the
* particular pages. One example (with blocks >= 2 * PAGE_SIZE)
* would be that mirror #1 has an I/O error on the first page,
* the second page is good, and mirror #2 has an I/O error on
* the second page, but the first page is good.
* Then the first page of the first mirror can be repaired by
* taking the first page of the second mirror, and the
* second page of the second mirror can be repaired by
* copying the contents of the 2nd page of the 1st mirror.
* One more note: if the pages of one mirror contain I/O
* errors, the checksum cannot be verified. In order to get
* the best data for repairing, the first attempt is to find
* a mirror without I/O errors and with a validated checksum.
* Only if this is not possible, the pages are picked from
* mirrors with I/O errors without considering the checksum.
* If the latter is the case, at the end, the checksum of the
* repaired area is verified in order to correctly maintain
* the statistics.
*/
sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
sizeof(*sblocks_for_recheck), GFP_KERNEL);
if (!sblocks_for_recheck) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
sctx->stat.read_errors++;
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
goto out;
}
/* setup the context, map the logical blocks and alloc the pages */
ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
if (ret) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors++;
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
goto out;
}
BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
sblock_bad = sblocks_for_recheck + failed_mirror_index;
/* build and submit the bios for the failed mirror, check checksums */
scrub_recheck_block(fs_info, sblock_bad, 1);
if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
sblock_bad->no_io_error_seen) {
/*
* the error disappeared after reading page by page, or
* the area was part of a huge bio and other parts of the
* bio caused I/O errors, or the block layer merged several
* read requests into one and the error is caused by a
* different bio (usually one of the two latter cases is
* the cause)
*/
spin_lock(&sctx->stat_lock);
sctx->stat.unverified_errors++;
sblock_to_check->data_corrected = 1;
spin_unlock(&sctx->stat_lock);
if (sctx->is_dev_replace)
scrub_write_block_to_dev_replace(sblock_bad);
goto out;
}
if (!sblock_bad->no_io_error_seen) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors++;
spin_unlock(&sctx->stat_lock);
if (__ratelimit(&rs))
scrub_print_warning("i/o error", sblock_to_check);
btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
} else if (sblock_bad->checksum_error) {
spin_lock(&sctx->stat_lock);
sctx->stat.csum_errors++;
spin_unlock(&sctx->stat_lock);
if (__ratelimit(&rs))
scrub_print_warning("checksum error", sblock_to_check);
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
} else if (sblock_bad->header_error) {
spin_lock(&sctx->stat_lock);
sctx->stat.verify_errors++;
spin_unlock(&sctx->stat_lock);
if (__ratelimit(&rs))
scrub_print_warning("checksum/header error",
sblock_to_check);
if (sblock_bad->generation_error)
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_GENERATION_ERRS);
else
btrfs_dev_stat_inc_and_print(dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
}
if (sctx->readonly) {
ASSERT(!sctx->is_dev_replace);
goto out;
}
/*
* now build and submit the bios for the other mirrors, check
* checksums.
* First try to pick the mirror which is completely without I/O
* errors and also does not have a checksum error.
* If one is found, and if a checksum is present, the full block
* that is known to contain an error is rewritten. Afterwards
* the block is known to be corrected.
* If a mirror is found which is completely correct, and no
* checksum is present, only those pages are rewritten that had
* an I/O error in the block to be repaired, since it cannot be
* determined, which copy of the other pages is better (and it
* could happen otherwise that a correct page would be
* overwritten by a bad one).
*/
for (mirror_index = 0; ;mirror_index++) {
struct scrub_block *sblock_other;
if (mirror_index == failed_mirror_index)
continue;
/* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
if (!scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
if (mirror_index >= BTRFS_MAX_MIRRORS)
break;
if (!sblocks_for_recheck[mirror_index].page_count)
break;
sblock_other = sblocks_for_recheck + mirror_index;
} else {
struct scrub_recover *r = sblock_bad->pagev[0]->recover;
int max_allowed = r->bbio->num_stripes -
r->bbio->num_tgtdevs;
if (mirror_index >= max_allowed)
break;
if (!sblocks_for_recheck[1].page_count)
break;
ASSERT(failed_mirror_index == 0);
sblock_other = sblocks_for_recheck + 1;
sblock_other->pagev[0]->mirror_num = 1 + mirror_index;
}
/* build and submit the bios, check checksums */
scrub_recheck_block(fs_info, sblock_other, 0);
if (!sblock_other->header_error &&
!sblock_other->checksum_error &&
sblock_other->no_io_error_seen) {
if (sctx->is_dev_replace) {
scrub_write_block_to_dev_replace(sblock_other);
goto corrected_error;
} else {
ret = scrub_repair_block_from_good_copy(
sblock_bad, sblock_other);
if (!ret)
goto corrected_error;
}
}
}
if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
goto did_not_correct_error;
/*
* In case of I/O errors in the area that is supposed to be
* repaired, continue by picking good copies of those pages.
* Select the good pages from mirrors to rewrite bad pages from
* the area to fix. Afterwards verify the checksum of the block
* that is supposed to be repaired. This verification step is
* only done for the purpose of statistic counting and for the
* final scrub report, whether errors remain.
* A perfect algorithm could make use of the checksum and try
* all possible combinations of pages from the different mirrors
* until the checksum verification succeeds. For example, when
* the 2nd page of mirror #1 faces I/O errors, and the 2nd page
* of mirror #2 is readable but the final checksum test fails,
* then the 2nd page of mirror #3 could be tried, whether now
* the final checksum succeeds. But this would be a rare
* exception and is therefore not implemented. At least it is
* avoided that the good copy is overwritten.
* A more useful improvement would be to pick the sectors
* without I/O error based on sector sizes (512 bytes on legacy
* disks) instead of on PAGE_SIZE. Then maybe 512 byte of one
* mirror could be repaired by taking 512 byte of a different
* mirror, even if other 512 byte sectors in the same PAGE_SIZE
* area are unreadable.
*/
success = 1;
for (page_num = 0; page_num < sblock_bad->page_count;
page_num++) {
struct scrub_page *spage_bad = sblock_bad->pagev[page_num];
struct scrub_block *sblock_other = NULL;
/* skip no-io-error page in scrub */
if (!spage_bad->io_error && !sctx->is_dev_replace)
continue;
if (scrub_is_page_on_raid56(sblock_bad->pagev[0])) {
/*
* In case of dev replace, if raid56 rebuild process
* didn't work out correct data, then copy the content
* in sblock_bad to make sure target device is identical
* to source device, instead of writing garbage data in
* sblock_for_recheck array to target device.
*/
sblock_other = NULL;
} else if (spage_bad->io_error) {
/* try to find no-io-error page in mirrors */
for (mirror_index = 0;
mirror_index < BTRFS_MAX_MIRRORS &&
sblocks_for_recheck[mirror_index].page_count > 0;
mirror_index++) {
if (!sblocks_for_recheck[mirror_index].
pagev[page_num]->io_error) {
sblock_other = sblocks_for_recheck +
mirror_index;
break;
}
}
if (!sblock_other)
success = 0;
}
if (sctx->is_dev_replace) {
/*
* did not find a mirror to fetch the page
* from. scrub_write_page_to_dev_replace()
* handles this case (page->io_error), by
* filling the block with zeros before
* submitting the write request
*/
if (!sblock_other)
sblock_other = sblock_bad;
if (scrub_write_page_to_dev_replace(sblock_other,
page_num) != 0) {
atomic64_inc(
&fs_info->dev_replace.num_write_errors);
success = 0;
}
} else if (sblock_other) {
ret = scrub_repair_page_from_good_copy(sblock_bad,
sblock_other,
page_num, 0);
if (0 == ret)
spage_bad->io_error = 0;
else
success = 0;
}
}
if (success && !sctx->is_dev_replace) {
if (is_metadata || have_csum) {
/*
* need to verify the checksum now that all
* sectors on disk are repaired (the write
* request for data to be repaired is on its way).
* Just be lazy and use scrub_recheck_block()
* which re-reads the data before the checksum
* is verified, but most likely the data comes out
* of the page cache.
*/
scrub_recheck_block(fs_info, sblock_bad, 1);
if (!sblock_bad->header_error &&
!sblock_bad->checksum_error &&
sblock_bad->no_io_error_seen)
goto corrected_error;
else
goto did_not_correct_error;
} else {
corrected_error:
spin_lock(&sctx->stat_lock);
sctx->stat.corrected_errors++;
sblock_to_check->data_corrected = 1;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"fixed up error at logical %llu on dev %s",
logical, rcu_str_deref(dev->name));
}
} else {
did_not_correct_error:
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"unable to fixup (regular) error at logical %llu on dev %s",
logical, rcu_str_deref(dev->name));
}
out:
if (sblocks_for_recheck) {
for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS;
mirror_index++) {
struct scrub_block *sblock = sblocks_for_recheck +
mirror_index;
struct scrub_recover *recover;
int page_index;
for (page_index = 0; page_index < sblock->page_count;
page_index++) {
sblock->pagev[page_index]->sblock = NULL;
recover = sblock->pagev[page_index]->recover;
if (recover) {
scrub_put_recover(fs_info, recover);
sblock->pagev[page_index]->recover =
NULL;
}
scrub_page_put(sblock->pagev[page_index]);
}
}
kfree(sblocks_for_recheck);
}
ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
memalloc_nofs_restore(nofs_flag);
if (ret < 0)
return ret;
return 0;
}
static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
{
if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
return 2;
else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
return 3;
else
return (int)bbio->num_stripes;
}
static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
u64 *raid_map,
u64 mapped_length,
int nstripes, int mirror,
int *stripe_index,
u64 *stripe_offset)
{
int i;
if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
/* RAID5/6 */
for (i = 0; i < nstripes; i++) {
if (raid_map[i] == RAID6_Q_STRIPE ||
raid_map[i] == RAID5_P_STRIPE)
continue;
if (logical >= raid_map[i] &&
logical < raid_map[i] + mapped_length)
break;
}
*stripe_index = i;
*stripe_offset = logical - raid_map[i];
} else {
/* The other RAID type */
*stripe_index = mirror;
*stripe_offset = 0;
}
}
static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
struct scrub_block *sblocks_for_recheck)
{
struct scrub_ctx *sctx = original_sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
u64 length = original_sblock->page_count * PAGE_SIZE;
u64 logical = original_sblock->pagev[0]->logical;
u64 generation = original_sblock->pagev[0]->generation;
u64 flags = original_sblock->pagev[0]->flags;
u64 have_csum = original_sblock->pagev[0]->have_csum;
struct scrub_recover *recover;
struct btrfs_bio *bbio;
u64 sublen;
u64 mapped_length;
u64 stripe_offset;
int stripe_index;
int page_index = 0;
int mirror_index;
int nmirrors;
int ret;
/*
* note: the two members refs and outstanding_pages
* are not used (and not set) in the blocks that are used for
* the recheck procedure
*/
while (length > 0) {
sublen = min_t(u64, length, PAGE_SIZE);
mapped_length = sublen;
bbio = NULL;
/*
* with a length of PAGE_SIZE, each returned stripe
* represents one mirror
*/
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
logical, &mapped_length, &bbio);
if (ret || !bbio || mapped_length < sublen) {
btrfs_put_bbio(bbio);
btrfs_bio_counter_dec(fs_info);
return -EIO;
}
recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
if (!recover) {
btrfs_put_bbio(bbio);
btrfs_bio_counter_dec(fs_info);
return -ENOMEM;
}
refcount_set(&recover->refs, 1);
recover->bbio = bbio;
recover->map_length = mapped_length;
BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
for (mirror_index = 0; mirror_index < nmirrors;
mirror_index++) {
struct scrub_block *sblock;
struct scrub_page *spage;
sblock = sblocks_for_recheck + mirror_index;
sblock->sctx = sctx;
spage = kzalloc(sizeof(*spage), GFP_NOFS);
if (!spage) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_put_recover(fs_info, recover);
return -ENOMEM;
}
scrub_page_get(spage);
sblock->pagev[page_index] = spage;
spage->sblock = sblock;
spage->flags = flags;
spage->generation = generation;
spage->logical = logical;
spage->have_csum = have_csum;
if (have_csum)
memcpy(spage->csum,
original_sblock->pagev[0]->csum,
sctx->fs_info->csum_size);
scrub_stripe_index_and_offset(logical,
bbio->map_type,
bbio->raid_map,
mapped_length,
bbio->num_stripes -
bbio->num_tgtdevs,
mirror_index,
&stripe_index,
&stripe_offset);
spage->physical = bbio->stripes[stripe_index].physical +
stripe_offset;
spage->dev = bbio->stripes[stripe_index].dev;
BUG_ON(page_index >= original_sblock->page_count);
spage->physical_for_dev_replace =
original_sblock->pagev[page_index]->
physical_for_dev_replace;
/* for missing devices, dev->bdev is NULL */
spage->mirror_num = mirror_index + 1;
sblock->page_count++;
spage->page = alloc_page(GFP_NOFS);
if (!spage->page)
goto leave_nomem;
scrub_get_recover(recover);
spage->recover = recover;
}
scrub_put_recover(fs_info, recover);
length -= sublen;
logical += sublen;
page_index++;
}
return 0;
}
static void scrub_bio_wait_endio(struct bio *bio)
{
complete(bio->bi_private);
}
static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
struct bio *bio,
struct scrub_page *spage)
{
DECLARE_COMPLETION_ONSTACK(done);
int ret;
int mirror_num;
bio->bi_iter.bi_sector = spage->logical >> 9;
bio->bi_private = &done;
bio->bi_end_io = scrub_bio_wait_endio;
mirror_num = spage->sblock->pagev[0]->mirror_num;
ret = raid56_parity_recover(fs_info, bio, spage->recover->bbio,
spage->recover->map_length,
mirror_num, 0);
if (ret)
return ret;
wait_for_completion_io(&done);
return blk_status_to_errno(bio->bi_status);
}
static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock)
{
struct scrub_page *first_page = sblock->pagev[0];
struct bio *bio;
int page_num;
/* All pages in sblock belong to the same stripe on the same device. */
ASSERT(first_page->dev);
if (!first_page->dev->bdev)
goto out;
bio = btrfs_io_bio_alloc(BIO_MAX_PAGES);
bio_set_dev(bio, first_page->dev->bdev);
for (page_num = 0; page_num < sblock->page_count; page_num++) {
struct scrub_page *spage = sblock->pagev[page_num];
WARN_ON(!spage->page);
bio_add_page(bio, spage->page, PAGE_SIZE, 0);
}
if (scrub_submit_raid56_bio_wait(fs_info, bio, first_page)) {
bio_put(bio);
goto out;
}
bio_put(bio);
scrub_recheck_block_checksum(sblock);
return;
out:
for (page_num = 0; page_num < sblock->page_count; page_num++)
sblock->pagev[page_num]->io_error = 1;
sblock->no_io_error_seen = 0;
}
/*
* this function will check the on disk data for checksum errors, header
* errors and read I/O errors. If any I/O errors happen, the exact pages
* which are errored are marked as being bad. The goal is to enable scrub
* to take those pages that are not errored from all the mirrors so that
* the pages that are errored in the just handled mirror can be repaired.
*/
static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
struct scrub_block *sblock,
int retry_failed_mirror)
{
int page_num;
sblock->no_io_error_seen = 1;
/* short cut for raid56 */
if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->pagev[0]))
return scrub_recheck_block_on_raid56(fs_info, sblock);
for (page_num = 0; page_num < sblock->page_count; page_num++) {
struct bio *bio;
struct scrub_page *spage = sblock->pagev[page_num];
if (spage->dev->bdev == NULL) {
spage->io_error = 1;
sblock->no_io_error_seen = 0;
continue;
}
WARN_ON(!spage->page);
bio = btrfs_io_bio_alloc(1);
bio_set_dev(bio, spage->dev->bdev);
bio_add_page(bio, spage->page, PAGE_SIZE, 0);
bio->bi_iter.bi_sector = spage->physical >> 9;
bio->bi_opf = REQ_OP_READ;
if (btrfsic_submit_bio_wait(bio)) {
spage->io_error = 1;
sblock->no_io_error_seen = 0;
}
bio_put(bio);
}
if (sblock->no_io_error_seen)
scrub_recheck_block_checksum(sblock);
}
static inline int scrub_check_fsid(u8 fsid[],
struct scrub_page *spage)
{
struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
int ret;
ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
return !ret;
}
static void scrub_recheck_block_checksum(struct scrub_block *sblock)
{
sblock->header_error = 0;
sblock->checksum_error = 0;
sblock->generation_error = 0;
if (sblock->pagev[0]->flags & BTRFS_EXTENT_FLAG_DATA)
scrub_checksum_data(sblock);
else
scrub_checksum_tree_block(sblock);
}
static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good)
{
int page_num;
int ret = 0;
for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
int ret_sub;
ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
sblock_good,
page_num, 1);
if (ret_sub)
ret = ret_sub;
}
return ret;
}
static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
struct scrub_block *sblock_good,
int page_num, int force_write)
{
struct scrub_page *spage_bad = sblock_bad->pagev[page_num];
struct scrub_page *spage_good = sblock_good->pagev[page_num];
struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
BUG_ON(spage_bad->page == NULL);
BUG_ON(spage_good->page == NULL);
if (force_write || sblock_bad->header_error ||
sblock_bad->checksum_error || spage_bad->io_error) {
struct bio *bio;
int ret;
if (!spage_bad->dev->bdev) {
btrfs_warn_rl(fs_info,
"scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
return -EIO;
}
bio = btrfs_io_bio_alloc(1);
bio_set_dev(bio, spage_bad->dev->bdev);
bio->bi_iter.bi_sector = spage_bad->physical >> 9;
bio->bi_opf = REQ_OP_WRITE;
ret = bio_add_page(bio, spage_good->page, PAGE_SIZE, 0);
if (PAGE_SIZE != ret) {
bio_put(bio);
return -EIO;
}
if (btrfsic_submit_bio_wait(bio)) {
btrfs_dev_stat_inc_and_print(spage_bad->dev,
BTRFS_DEV_STAT_WRITE_ERRS);
atomic64_inc(&fs_info->dev_replace.num_write_errors);
bio_put(bio);
return -EIO;
}
bio_put(bio);
}
return 0;
}
static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
{
struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
int page_num;
/*
* This block is used for the check of the parity on the source device,
* so the data needn't be written into the destination device.
*/
if (sblock->sparity)
return;
for (page_num = 0; page_num < sblock->page_count; page_num++) {
int ret;
ret = scrub_write_page_to_dev_replace(sblock, page_num);
if (ret)
atomic64_inc(&fs_info->dev_replace.num_write_errors);
}
}
static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
int page_num)
{
struct scrub_page *spage = sblock->pagev[page_num];
BUG_ON(spage->page == NULL);
if (spage->io_error)
clear_page(page_address(spage->page));
return scrub_add_page_to_wr_bio(sblock->sctx, spage);
}
static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
struct scrub_page *spage)
{
struct scrub_bio *sbio;
int ret;
mutex_lock(&sctx->wr_lock);
again:
if (!sctx->wr_curr_bio) {
sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
GFP_KERNEL);
if (!sctx->wr_curr_bio) {
mutex_unlock(&sctx->wr_lock);
return -ENOMEM;
}
sctx->wr_curr_bio->sctx = sctx;
sctx->wr_curr_bio->page_count = 0;
}
sbio = sctx->wr_curr_bio;
if (sbio->page_count == 0) {
struct bio *bio;
sbio->physical = spage->physical_for_dev_replace;
sbio->logical = spage->logical;
sbio->dev = sctx->wr_tgtdev;
bio = sbio->bio;
if (!bio) {
bio = btrfs_io_bio_alloc(sctx->pages_per_wr_bio);
sbio->bio = bio;
}
bio->bi_private = sbio;
bio->bi_end_io = scrub_wr_bio_end_io;
bio_set_dev(bio, sbio->dev->bdev);
bio->bi_iter.bi_sector = sbio->physical >> 9;
bio->bi_opf = REQ_OP_WRITE;
sbio->status = 0;
} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
spage->physical_for_dev_replace ||
sbio->logical + sbio->page_count * PAGE_SIZE !=
spage->logical) {
scrub_wr_submit(sctx);
goto again;
}
ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
if (ret != PAGE_SIZE) {
if (sbio->page_count < 1) {
bio_put(sbio->bio);
sbio->bio = NULL;
mutex_unlock(&sctx->wr_lock);
return -EIO;
}
scrub_wr_submit(sctx);
goto again;
}
sbio->pagev[sbio->page_count] = spage;
scrub_page_get(spage);
sbio->page_count++;
if (sbio->page_count == sctx->pages_per_wr_bio)
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
return 0;
}
static void scrub_wr_submit(struct scrub_ctx *sctx)
{
struct scrub_bio *sbio;
if (!sctx->wr_curr_bio)
return;
sbio = sctx->wr_curr_bio;
sctx->wr_curr_bio = NULL;
WARN_ON(!sbio->bio->bi_disk);
scrub_pending_bio_inc(sctx);
/* process all writes in a single worker thread. Then the block layer
* orders the requests before sending them to the driver which
* doubled the write performance on spinning disks when measured
* with Linux 3.5 */
btrfsic_submit_bio(sbio->bio);
}
static void scrub_wr_bio_end_io(struct bio *bio)
{
struct scrub_bio *sbio = bio->bi_private;
struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
sbio->status = bio->bi_status;
sbio->bio = bio;
btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL);
btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
}
static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
{
struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
struct scrub_ctx *sctx = sbio->sctx;
int i;
WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
if (sbio->status) {
struct btrfs_dev_replace *dev_replace =
&sbio->sctx->fs_info->dev_replace;
for (i = 0; i < sbio->page_count; i++) {
struct scrub_page *spage = sbio->pagev[i];
spage->io_error = 1;
atomic64_inc(&dev_replace->num_write_errors);
}
}
for (i = 0; i < sbio->page_count; i++)
scrub_page_put(sbio->pagev[i]);
bio_put(sbio->bio);
kfree(sbio);
scrub_pending_bio_dec(sctx);
}
static int scrub_checksum(struct scrub_block *sblock)
{
u64 flags;
int ret;
/*
* No need to initialize these stats currently,
* because this function only use return value
* instead of these stats value.
*
* Todo:
* always use stats
*/
sblock->header_error = 0;
sblock->generation_error = 0;
sblock->checksum_error = 0;
WARN_ON(sblock->page_count < 1);
flags = sblock->pagev[0]->flags;
ret = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA)
ret = scrub_checksum_data(sblock);
else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
ret = scrub_checksum_tree_block(sblock);
else if (flags & BTRFS_EXTENT_FLAG_SUPER)
(void)scrub_checksum_super(sblock);
else
WARN_ON(1);
if (ret)
scrub_handle_errored_block(sblock);
return ret;
}
static int scrub_checksum_data(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 csum[BTRFS_CSUM_SIZE];
struct scrub_page *spage;
char *kaddr;
BUG_ON(sblock->page_count < 1);
spage = sblock->pagev[0];
if (!spage->have_csum)
return 0;
kaddr = page_address(spage->page);
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
/*
* In scrub_pages() and scrub_pages_for_parity() we ensure each spage
* only contains one sector of data.
*/
crypto_shash_digest(shash, kaddr, fs_info->sectorsize, csum);
if (memcmp(csum, spage->csum, fs_info->csum_size))
sblock->checksum_error = 1;
return sblock->checksum_error;
}
static int scrub_checksum_tree_block(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_header *h;
struct btrfs_fs_info *fs_info = sctx->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 calculated_csum[BTRFS_CSUM_SIZE];
u8 on_disk_csum[BTRFS_CSUM_SIZE];
/*
* This is done in sectorsize steps even for metadata as there's a
* constraint for nodesize to be aligned to sectorsize. This will need
* to change so we don't misuse data and metadata units like that.
*/
const u32 sectorsize = sctx->fs_info->sectorsize;
const int num_sectors = fs_info->nodesize >> fs_info->sectorsize_bits;
int i;
struct scrub_page *spage;
char *kaddr;
BUG_ON(sblock->page_count < 1);
/* Each member in pagev is just one block, not a full page */
ASSERT(sblock->page_count == num_sectors);
spage = sblock->pagev[0];
kaddr = page_address(spage->page);
h = (struct btrfs_header *)kaddr;
memcpy(on_disk_csum, h->csum, sctx->fs_info->csum_size);
/*
* we don't use the getter functions here, as we
* a) don't have an extent buffer and
* b) the page is already kmapped
*/
if (spage->logical != btrfs_stack_header_bytenr(h))
sblock->header_error = 1;
if (spage->generation != btrfs_stack_header_generation(h)) {
sblock->header_error = 1;
sblock->generation_error = 1;
}
if (!scrub_check_fsid(h->fsid, spage))
sblock->header_error = 1;
if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
BTRFS_UUID_SIZE))
sblock->header_error = 1;
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
sectorsize - BTRFS_CSUM_SIZE);
for (i = 1; i < num_sectors; i++) {
kaddr = page_address(sblock->pagev[i]->page);
crypto_shash_update(shash, kaddr, sectorsize);
}
crypto_shash_final(shash, calculated_csum);
if (memcmp(calculated_csum, on_disk_csum, sctx->fs_info->csum_size))
sblock->checksum_error = 1;
return sblock->header_error || sblock->checksum_error;
}
static int scrub_checksum_super(struct scrub_block *sblock)
{
struct btrfs_super_block *s;
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 calculated_csum[BTRFS_CSUM_SIZE];
struct scrub_page *spage;
char *kaddr;
int fail_gen = 0;
int fail_cor = 0;
BUG_ON(sblock->page_count < 1);
spage = sblock->pagev[0];
kaddr = page_address(spage->page);
s = (struct btrfs_super_block *)kaddr;
if (spage->logical != btrfs_super_bytenr(s))
++fail_cor;
if (spage->generation != btrfs_super_generation(s))
++fail_gen;
if (!scrub_check_fsid(s->fsid, spage))
++fail_cor;
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_digest(shash, kaddr + BTRFS_CSUM_SIZE,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, calculated_csum);
if (memcmp(calculated_csum, s->csum, sctx->fs_info->csum_size))
++fail_cor;
if (fail_cor + fail_gen) {
/*
* if we find an error in a super block, we just report it.
* They will get written with the next transaction commit
* anyway
*/
spin_lock(&sctx->stat_lock);
++sctx->stat.super_errors;
spin_unlock(&sctx->stat_lock);
if (fail_cor)
btrfs_dev_stat_inc_and_print(spage->dev,
BTRFS_DEV_STAT_CORRUPTION_ERRS);
else
btrfs_dev_stat_inc_and_print(spage->dev,
BTRFS_DEV_STAT_GENERATION_ERRS);
}
return fail_cor + fail_gen;
}
static void scrub_block_get(struct scrub_block *sblock)
{
refcount_inc(&sblock->refs);
}
static void scrub_block_put(struct scrub_block *sblock)
{
if (refcount_dec_and_test(&sblock->refs)) {
int i;
if (sblock->sparity)
scrub_parity_put(sblock->sparity);
for (i = 0; i < sblock->page_count; i++)
scrub_page_put(sblock->pagev[i]);
kfree(sblock);
}
}
static void scrub_page_get(struct scrub_page *spage)
{
atomic_inc(&spage->refs);
}
static void scrub_page_put(struct scrub_page *spage)
{
if (atomic_dec_and_test(&spage->refs)) {
if (spage->page)
__free_page(spage->page);
kfree(spage);
}
}
static void scrub_submit(struct scrub_ctx *sctx)
{
struct scrub_bio *sbio;
if (sctx->curr == -1)
return;
sbio = sctx->bios[sctx->curr];
sctx->curr = -1;
scrub_pending_bio_inc(sctx);
btrfsic_submit_bio(sbio->bio);
}
static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
struct scrub_page *spage)
{
struct scrub_block *sblock = spage->sblock;
struct scrub_bio *sbio;
int ret;
again:
/*
* grab a fresh bio or wait for one to become available
*/
while (sctx->curr == -1) {
spin_lock(&sctx->list_lock);
sctx->curr = sctx->first_free;
if (sctx->curr != -1) {
sctx->first_free = sctx->bios[sctx->curr]->next_free;
sctx->bios[sctx->curr]->next_free = -1;
sctx->bios[sctx->curr]->page_count = 0;
spin_unlock(&sctx->list_lock);
} else {
spin_unlock(&sctx->list_lock);
wait_event(sctx->list_wait, sctx->first_free != -1);
}
}
sbio = sctx->bios[sctx->curr];
if (sbio->page_count == 0) {
struct bio *bio;
sbio->physical = spage->physical;
sbio->logical = spage->logical;
sbio->dev = spage->dev;
bio = sbio->bio;
if (!bio) {
bio = btrfs_io_bio_alloc(sctx->pages_per_rd_bio);
sbio->bio = bio;
}
bio->bi_private = sbio;
bio->bi_end_io = scrub_bio_end_io;
bio_set_dev(bio, sbio->dev->bdev);
bio->bi_iter.bi_sector = sbio->physical >> 9;
bio->bi_opf = REQ_OP_READ;
sbio->status = 0;
} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
spage->physical ||
sbio->logical + sbio->page_count * PAGE_SIZE !=
spage->logical ||
sbio->dev != spage->dev) {
scrub_submit(sctx);
goto again;
}
sbio->pagev[sbio->page_count] = spage;
ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
if (ret != PAGE_SIZE) {
if (sbio->page_count < 1) {
bio_put(sbio->bio);
sbio->bio = NULL;
return -EIO;
}
scrub_submit(sctx);
goto again;
}
scrub_block_get(sblock); /* one for the page added to the bio */
atomic_inc(&sblock->outstanding_pages);
sbio->page_count++;
if (sbio->page_count == sctx->pages_per_rd_bio)
scrub_submit(sctx);
return 0;
}
static void scrub_missing_raid56_end_io(struct bio *bio)
{
struct scrub_block *sblock = bio->bi_private;
struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
if (bio->bi_status)
sblock->no_io_error_seen = 0;
bio_put(bio);
btrfs_queue_work(fs_info->scrub_workers, &sblock->work);
}
static void scrub_missing_raid56_worker(struct btrfs_work *work)
{
struct scrub_block *sblock = container_of(work, struct scrub_block, work);
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
u64 logical;
struct btrfs_device *dev;
logical = sblock->pagev[0]->logical;
dev = sblock->pagev[0]->dev;
if (sblock->no_io_error_seen)
scrub_recheck_block_checksum(sblock);
if (!sblock->no_io_error_seen) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"IO error rebuilding logical %llu for dev %s",
logical, rcu_str_deref(dev->name));
} else if (sblock->header_error || sblock->checksum_error) {
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
btrfs_err_rl_in_rcu(fs_info,
"failed to rebuild valid logical %llu for dev %s",
logical, rcu_str_deref(dev->name));
} else {
scrub_write_block_to_dev_replace(sblock);
}
if (sctx->is_dev_replace && sctx->flush_all_writes) {
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
}
scrub_block_put(sblock);
scrub_pending_bio_dec(sctx);
}
static void scrub_missing_raid56_pages(struct scrub_block *sblock)
{
struct scrub_ctx *sctx = sblock->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
u64 length = sblock->page_count * PAGE_SIZE;
u64 logical = sblock->pagev[0]->logical;
struct btrfs_bio *bbio = NULL;
struct bio *bio;
struct btrfs_raid_bio *rbio;
int ret;
int i;
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
&length, &bbio);
if (ret || !bbio || !bbio->raid_map)
goto bbio_out;
if (WARN_ON(!sctx->is_dev_replace ||
!(bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
/*
* We shouldn't be scrubbing a missing device. Even for dev
* replace, we should only get here for RAID 5/6. We either
* managed to mount something with no mirrors remaining or
* there's a bug in scrub_remap_extent()/btrfs_map_block().
*/
goto bbio_out;
}
bio = btrfs_io_bio_alloc(0);
bio->bi_iter.bi_sector = logical >> 9;
bio->bi_private = sblock;
bio->bi_end_io = scrub_missing_raid56_end_io;
rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
if (!rbio)
goto rbio_out;
for (i = 0; i < sblock->page_count; i++) {
struct scrub_page *spage = sblock->pagev[i];
raid56_add_scrub_pages(rbio, spage->page, spage->logical);
}
btrfs_init_work(&sblock->work, scrub_missing_raid56_worker, NULL, NULL);
scrub_block_get(sblock);
scrub_pending_bio_inc(sctx);
raid56_submit_missing_rbio(rbio);
return;
rbio_out:
bio_put(bio);
bbio_out:
btrfs_bio_counter_dec(fs_info);
btrfs_put_bbio(bbio);
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
}
static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u32 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u8 *csum,
u64 physical_for_dev_replace)
{
struct scrub_block *sblock;
const u32 sectorsize = sctx->fs_info->sectorsize;
int index;
sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
if (!sblock) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
/* one ref inside this function, plus one for each page added to
* a bio later on */
refcount_set(&sblock->refs, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
for (index = 0; len > 0; index++) {
struct scrub_page *spage;
/*
* Here we will allocate one page for one sector to scrub.
* This is fine if PAGE_SIZE == sectorsize, but will cost
* more memory for PAGE_SIZE > sectorsize case.
*/
u32 l = min(sectorsize, len);
spage = kzalloc(sizeof(*spage), GFP_KERNEL);
if (!spage) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_block_put(sblock);
return -ENOMEM;
}
BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
scrub_page_get(spage);
sblock->pagev[index] = spage;
spage->sblock = sblock;
spage->dev = dev;
spage->flags = flags;
spage->generation = gen;
spage->logical = logical;
spage->physical = physical;
spage->physical_for_dev_replace = physical_for_dev_replace;
spage->mirror_num = mirror_num;
if (csum) {
spage->have_csum = 1;
memcpy(spage->csum, csum, sctx->fs_info->csum_size);
} else {
spage->have_csum = 0;
}
sblock->page_count++;
spage->page = alloc_page(GFP_KERNEL);
if (!spage->page)
goto leave_nomem;
len -= l;
logical += l;
physical += l;
physical_for_dev_replace += l;
}
WARN_ON(sblock->page_count == 0);
if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
/*
* This case should only be hit for RAID 5/6 device replace. See
* the comment in scrub_missing_raid56_pages() for details.
*/
scrub_missing_raid56_pages(sblock);
} else {
for (index = 0; index < sblock->page_count; index++) {
struct scrub_page *spage = sblock->pagev[index];
int ret;
ret = scrub_add_page_to_rd_bio(sctx, spage);
if (ret) {
scrub_block_put(sblock);
return ret;
}
}
if (flags & BTRFS_EXTENT_FLAG_SUPER)
scrub_submit(sctx);
}
/* last one frees, either here or in bio completion for last page */
scrub_block_put(sblock);
return 0;
}
static void scrub_bio_end_io(struct bio *bio)
{
struct scrub_bio *sbio = bio->bi_private;
struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
sbio->status = bio->bi_status;
sbio->bio = bio;
btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
}
static void scrub_bio_end_io_worker(struct btrfs_work *work)
{
struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
struct scrub_ctx *sctx = sbio->sctx;
int i;
BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
if (sbio->status) {
for (i = 0; i < sbio->page_count; i++) {
struct scrub_page *spage = sbio->pagev[i];
spage->io_error = 1;
spage->sblock->no_io_error_seen = 0;
}
}
/* now complete the scrub_block items that have all pages completed */
for (i = 0; i < sbio->page_count; i++) {
struct scrub_page *spage = sbio->pagev[i];
struct scrub_block *sblock = spage->sblock;
if (atomic_dec_and_test(&sblock->outstanding_pages))
scrub_block_complete(sblock);
scrub_block_put(sblock);
}
bio_put(sbio->bio);
sbio->bio = NULL;
spin_lock(&sctx->list_lock);
sbio->next_free = sctx->first_free;
sctx->first_free = sbio->index;
spin_unlock(&sctx->list_lock);
if (sctx->is_dev_replace && sctx->flush_all_writes) {
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
}
scrub_pending_bio_dec(sctx);
}
static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
unsigned long *bitmap,
u64 start, u32 len)
{
u64 offset;
u32 nsectors;
u32 sectorsize_bits = sparity->sctx->fs_info->sectorsize_bits;
if (len >= sparity->stripe_len) {
bitmap_set(bitmap, 0, sparity->nsectors);
return;
}
start -= sparity->logic_start;
start = div64_u64_rem(start, sparity->stripe_len, &offset);
offset = offset >> sectorsize_bits;
nsectors = len >> sectorsize_bits;
if (offset + nsectors <= sparity->nsectors) {
bitmap_set(bitmap, offset, nsectors);
return;
}
bitmap_set(bitmap, offset, sparity->nsectors - offset);
bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
}
static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
u64 start, u32 len)
{
__scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
}
static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
u64 start, u32 len)
{
__scrub_mark_bitmap(sparity, sparity->dbitmap, start, len);
}
static void scrub_block_complete(struct scrub_block *sblock)
{
int corrupted = 0;
if (!sblock->no_io_error_seen) {
corrupted = 1;
scrub_handle_errored_block(sblock);
} else {
/*
* if has checksum error, write via repair mechanism in
* dev replace case, otherwise write here in dev replace
* case.
*/
corrupted = scrub_checksum(sblock);
if (!corrupted && sblock->sctx->is_dev_replace)
scrub_write_block_to_dev_replace(sblock);
}
if (sblock->sparity && corrupted && !sblock->data_corrected) {
u64 start = sblock->pagev[0]->logical;
u64 end = sblock->pagev[sblock->page_count - 1]->logical +
PAGE_SIZE;
ASSERT(end - start <= U32_MAX);
scrub_parity_mark_sectors_error(sblock->sparity,
start, end - start);
}
}
static void drop_csum_range(struct scrub_ctx *sctx, struct btrfs_ordered_sum *sum)
{
sctx->stat.csum_discards += sum->len >> sctx->fs_info->sectorsize_bits;
list_del(&sum->list);
kfree(sum);
}
/*
* Find the desired csum for range [logical, logical + sectorsize), and store
* the csum into @csum.
*
* The search source is sctx->csum_list, which is a pre-populated list
* storing bytenr ordered csum ranges. We're reponsible to cleanup any range
* that is before @logical.
*
* Return 0 if there is no csum for the range.
* Return 1 if there is csum for the range and copied to @csum.
*/
static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
{
bool found = false;
while (!list_empty(&sctx->csum_list)) {
struct btrfs_ordered_sum *sum = NULL;
unsigned long index;
unsigned long num_sectors;
sum = list_first_entry(&sctx->csum_list,
struct btrfs_ordered_sum, list);
/* The current csum range is beyond our range, no csum found */
if (sum->bytenr > logical)
break;
/*
* The current sum is before our bytenr, since scrub is always
* done in bytenr order, the csum will never be used anymore,
* clean it up so that later calls won't bother with the range,
* and continue search the next range.
*/
if (sum->bytenr + sum->len <= logical) {
drop_csum_range(sctx, sum);
continue;
}
/* Now the csum range covers our bytenr, copy the csum */
found = true;
index = (logical - sum->bytenr) >> sctx->fs_info->sectorsize_bits;
num_sectors = sum->len >> sctx->fs_info->sectorsize_bits;
memcpy(csum, sum->sums + index * sctx->fs_info->csum_size,
sctx->fs_info->csum_size);
/* Cleanup the range if we're at the end of the csum range */
if (index == num_sectors - 1)
drop_csum_range(sctx, sum);
break;
}
if (!found)
return 0;
return 1;
}
/* scrub extent tries to collect up to 64 kB for each bio */
static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
u64 logical, u32 len,
u64 physical, struct btrfs_device *dev, u64 flags,
u64 gen, int mirror_num, u64 physical_for_dev_replace)
{
int ret;
u8 csum[BTRFS_CSUM_SIZE];
u32 blocksize;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
blocksize = map->stripe_len;
else
blocksize = sctx->fs_info->sectorsize;
spin_lock(&sctx->stat_lock);
sctx->stat.data_extents_scrubbed++;
sctx->stat.data_bytes_scrubbed += len;
spin_unlock(&sctx->stat_lock);
} else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
blocksize = map->stripe_len;
else
blocksize = sctx->fs_info->nodesize;
spin_lock(&sctx->stat_lock);
sctx->stat.tree_extents_scrubbed++;
sctx->stat.tree_bytes_scrubbed += len;
spin_unlock(&sctx->stat_lock);
} else {
blocksize = sctx->fs_info->sectorsize;
WARN_ON(1);
}
while (len) {
u32 l = min(len, blocksize);
int have_csum = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
/* push csums to sbio */
have_csum = scrub_find_csum(sctx, logical, csum);
if (have_csum == 0)
++sctx->stat.no_csum;
}
ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
mirror_num, have_csum ? csum : NULL,
physical_for_dev_replace);
if (ret)
return ret;
len -= l;
logical += l;
physical += l;
physical_for_dev_replace += l;
}
return 0;
}
static int scrub_pages_for_parity(struct scrub_parity *sparity,
u64 logical, u32 len,
u64 physical, struct btrfs_device *dev,
u64 flags, u64 gen, int mirror_num, u8 *csum)
{
struct scrub_ctx *sctx = sparity->sctx;
struct scrub_block *sblock;
const u32 sectorsize = sctx->fs_info->sectorsize;
int index;
ASSERT(IS_ALIGNED(len, sectorsize));
sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
if (!sblock) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
/* one ref inside this function, plus one for each page added to
* a bio later on */
refcount_set(&sblock->refs, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
sblock->sparity = sparity;
scrub_parity_get(sparity);
for (index = 0; len > 0; index++) {
struct scrub_page *spage;
spage = kzalloc(sizeof(*spage), GFP_KERNEL);
if (!spage) {
leave_nomem:
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
scrub_block_put(sblock);
return -ENOMEM;
}
BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
/* For scrub block */
scrub_page_get(spage);
sblock->pagev[index] = spage;
/* For scrub parity */
scrub_page_get(spage);
list_add_tail(&spage->list, &sparity->spages);
spage->sblock = sblock;
spage->dev = dev;
spage->flags = flags;
spage->generation = gen;
spage->logical = logical;
spage->physical = physical;
spage->mirror_num = mirror_num;
if (csum) {
spage->have_csum = 1;
memcpy(spage->csum, csum, sctx->fs_info->csum_size);
} else {
spage->have_csum = 0;
}
sblock->page_count++;
spage->page = alloc_page(GFP_KERNEL);
if (!spage->page)
goto leave_nomem;
/* Iterate over the stripe range in sectorsize steps */
len -= sectorsize;
logical += sectorsize;
physical += sectorsize;
}
WARN_ON(sblock->page_count == 0);
for (index = 0; index < sblock->page_count; index++) {
struct scrub_page *spage = sblock->pagev[index];
int ret;
ret = scrub_add_page_to_rd_bio(sctx, spage);
if (ret) {
scrub_block_put(sblock);
return ret;
}
}
/* last one frees, either here or in bio completion for last page */
scrub_block_put(sblock);
return 0;
}
static int scrub_extent_for_parity(struct scrub_parity *sparity,
u64 logical, u32 len,
u64 physical, struct btrfs_device *dev,
u64 flags, u64 gen, int mirror_num)
{
struct scrub_ctx *sctx = sparity->sctx;
int ret;
u8 csum[BTRFS_CSUM_SIZE];
u32 blocksize;
if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
scrub_parity_mark_sectors_error(sparity, logical, len);
return 0;
}
if (flags & BTRFS_EXTENT_FLAG_DATA) {
blocksize = sparity->stripe_len;
} else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
blocksize = sparity->stripe_len;
} else {
blocksize = sctx->fs_info->sectorsize;
WARN_ON(1);
}
while (len) {
u32 l = min(len, blocksize);
int have_csum = 0;
if (flags & BTRFS_EXTENT_FLAG_DATA) {
/* push csums to sbio */
have_csum = scrub_find_csum(sctx, logical, csum);
if (have_csum == 0)
goto skip;
}
ret = scrub_pages_for_parity(sparity, logical, l, physical, dev,
flags, gen, mirror_num,
have_csum ? csum : NULL);
if (ret)
return ret;
skip:
len -= l;
logical += l;
physical += l;
}
return 0;
}
/*
* Given a physical address, this will calculate it's
* logical offset. if this is a parity stripe, it will return
* the most left data stripe's logical offset.
*
* return 0 if it is a data stripe, 1 means parity stripe.
*/
static int get_raid56_logic_offset(u64 physical, int num,
struct map_lookup *map, u64 *offset,
u64 *stripe_start)
{
int i;
int j = 0;
u64 stripe_nr;
u64 last_offset;
u32 stripe_index;
u32 rot;
const int data_stripes = nr_data_stripes(map);
last_offset = (physical - map->stripes[num].physical) * data_stripes;
if (stripe_start)
*stripe_start = last_offset;
*offset = last_offset;
for (i = 0; i < data_stripes; i++) {
*offset = last_offset + i * map->stripe_len;
stripe_nr = div64_u64(*offset, map->stripe_len);
stripe_nr = div_u64(stripe_nr, data_stripes);
/* Work out the disk rotation on this stripe-set */
stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
/* calculate which stripe this data locates */
rot += i;
stripe_index = rot % map->num_stripes;
if (stripe_index == num)
return 0;
if (stripe_index < num)
j++;
}
*offset = last_offset + j * map->stripe_len;
return 1;
}
static void scrub_free_parity(struct scrub_parity *sparity)
{
struct scrub_ctx *sctx = sparity->sctx;
struct scrub_page *curr, *next;
int nbits;
nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors);
if (nbits) {
spin_lock(&sctx->stat_lock);
sctx->stat.read_errors += nbits;
sctx->stat.uncorrectable_errors += nbits;
spin_unlock(&sctx->stat_lock);
}
list_for_each_entry_safe(curr, next, &sparity->spages, list) {
list_del_init(&curr->list);
scrub_page_put(curr);
}
kfree(sparity);
}
static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
{
struct scrub_parity *sparity = container_of(work, struct scrub_parity,
work);
struct scrub_ctx *sctx = sparity->sctx;
scrub_free_parity(sparity);
scrub_pending_bio_dec(sctx);
}
static void scrub_parity_bio_endio(struct bio *bio)
{
struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
if (bio->bi_status)
bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
sparity->nsectors);
bio_put(bio);
btrfs_init_work(&sparity->work, scrub_parity_bio_endio_worker, NULL,
NULL);
btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
}
static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
{
struct scrub_ctx *sctx = sparity->sctx;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct bio *bio;
struct btrfs_raid_bio *rbio;
struct btrfs_bio *bbio = NULL;
u64 length;
int ret;
if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap,
sparity->nsectors))
goto out;
length = sparity->logic_end - sparity->logic_start;
btrfs_bio_counter_inc_blocked(fs_info);
ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
&length, &bbio);
if (ret || !bbio || !bbio->raid_map)
goto bbio_out;
bio = btrfs_io_bio_alloc(0);
bio->bi_iter.bi_sector = sparity->logic_start >> 9;
bio->bi_private = sparity;
bio->bi_end_io = scrub_parity_bio_endio;
rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
length, sparity->scrub_dev,
sparity->dbitmap,
sparity->nsectors);
if (!rbio)
goto rbio_out;
scrub_pending_bio_inc(sctx);
raid56_parity_submit_scrub_rbio(rbio);
return;
rbio_out:
bio_put(bio);
bbio_out:
btrfs_bio_counter_dec(fs_info);
btrfs_put_bbio(bbio);
bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
sparity->nsectors);
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
out:
scrub_free_parity(sparity);
}
static inline int scrub_calc_parity_bitmap_len(int nsectors)
{
return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
}
static void scrub_parity_get(struct scrub_parity *sparity)
{
refcount_inc(&sparity->refs);
}
static void scrub_parity_put(struct scrub_parity *sparity)
{
if (!refcount_dec_and_test(&sparity->refs))
return;
scrub_parity_check_and_repair(sparity);
}
static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
struct map_lookup *map,
struct btrfs_device *sdev,
struct btrfs_path *path,
u64 logic_start,
u64 logic_end)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_root *csum_root = fs_info->csum_root;
struct btrfs_extent_item *extent;
struct btrfs_bio *bbio = NULL;
u64 flags;
int ret;
int slot;
struct extent_buffer *l;
struct btrfs_key key;
u64 generation;
u64 extent_logical;
u64 extent_physical;
/* Check the comment in scrub_stripe() for why u32 is enough here */
u32 extent_len;
u64 mapped_length;
struct btrfs_device *extent_dev;
struct scrub_parity *sparity;
int nsectors;
int bitmap_len;
int extent_mirror_num;
int stop_loop = 0;
ASSERT(map->stripe_len <= U32_MAX);
nsectors = map->stripe_len >> fs_info->sectorsize_bits;
bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
GFP_NOFS);
if (!sparity) {
spin_lock(&sctx->stat_lock);
sctx->stat.malloc_errors++;
spin_unlock(&sctx->stat_lock);
return -ENOMEM;
}
ASSERT(map->stripe_len <= U32_MAX);
sparity->stripe_len = map->stripe_len;
sparity->nsectors = nsectors;
sparity->sctx = sctx;
sparity->scrub_dev = sdev;
sparity->logic_start = logic_start;
sparity->logic_end = logic_end;
refcount_set(&sparity->refs, 1);
INIT_LIST_HEAD(&sparity->spages);
sparity->dbitmap = sparity->bitmap;
sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
ret = 0;
while (logic_start < logic_end) {
if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
key.objectid = logic_start;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_extent_item(root, path, 0);
if (ret < 0)
goto out;
if (ret > 0) {
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &key,
path, 0, 0);
if (ret < 0)
goto out;
}
}
stop_loop = 0;
while (1) {
u64 bytes;
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
stop_loop = 1;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.type != BTRFS_EXTENT_ITEM_KEY &&
key.type != BTRFS_METADATA_ITEM_KEY)
goto next;
if (key.type == BTRFS_METADATA_ITEM_KEY)
bytes = fs_info->nodesize;
else
bytes = key.offset;
if (key.objectid + bytes <= logic_start)
goto next;
if (key.objectid >= logic_end) {
stop_loop = 1;
break;
}
while (key.objectid >= logic_start + map->stripe_len)
logic_start += map->stripe_len;
extent = btrfs_item_ptr(l, slot,
struct btrfs_extent_item);
flags = btrfs_extent_flags(l, extent);
generation = btrfs_extent_generation(l, extent);
if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
(key.objectid < logic_start ||
key.objectid + bytes >
logic_start + map->stripe_len)) {
btrfs_err(fs_info,
"scrub: tree block %llu spanning stripes, ignored. logical=%llu",
key.objectid, logic_start);
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
goto next;
}
again:
extent_logical = key.objectid;
ASSERT(bytes <= U32_MAX);
extent_len = bytes;
if (extent_logical < logic_start) {
extent_len -= logic_start - extent_logical;
extent_logical = logic_start;
}
if (extent_logical + extent_len >
logic_start + map->stripe_len)
extent_len = logic_start + map->stripe_len -
extent_logical;
scrub_parity_mark_sectors_data(sparity, extent_logical,
extent_len);
mapped_length = extent_len;
bbio = NULL;
ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
extent_logical, &mapped_length, &bbio,
0);
if (!ret) {
if (!bbio || mapped_length < extent_len)
ret = -EIO;
}
if (ret) {
btrfs_put_bbio(bbio);
goto out;
}
extent_physical = bbio->stripes[0].physical;
extent_mirror_num = bbio->mirror_num;
extent_dev = bbio->stripes[0].dev;
btrfs_put_bbio(bbio);
ret = btrfs_lookup_csums_range(csum_root,
extent_logical,
extent_logical + extent_len - 1,
&sctx->csum_list, 1);
if (ret)
goto out;
ret = scrub_extent_for_parity(sparity, extent_logical,
extent_len,
extent_physical,
extent_dev, flags,
generation,
extent_mirror_num);
scrub_free_csums(sctx);
if (ret)
goto out;
if (extent_logical + extent_len <
key.objectid + bytes) {
logic_start += map->stripe_len;
if (logic_start >= logic_end) {
stop_loop = 1;
break;
}
if (logic_start < key.objectid + bytes) {
cond_resched();
goto again;
}
}
next:
path->slots[0]++;
}
btrfs_release_path(path);
if (stop_loop)
break;
logic_start += map->stripe_len;
}
out:
if (ret < 0) {
ASSERT(logic_end - logic_start <= U32_MAX);
scrub_parity_mark_sectors_error(sparity, logic_start,
logic_end - logic_start);
}
scrub_parity_put(sparity);
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
btrfs_release_path(path);
return ret < 0 ? ret : 0;
}
static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
struct map_lookup *map,
struct btrfs_device *scrub_dev,
int num, u64 base, u64 length,
struct btrfs_block_group *cache)
{
struct btrfs_path *path, *ppath;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_root *csum_root = fs_info->csum_root;
struct btrfs_extent_item *extent;
struct blk_plug plug;
u64 flags;
int ret;
int slot;
u64 nstripes;
struct extent_buffer *l;
u64 physical;
u64 logical;
u64 logic_end;
u64 physical_end;
u64 generation;
int mirror_num;
struct reada_control *reada1;
struct reada_control *reada2;
struct btrfs_key key;
struct btrfs_key key_end;
u64 increment = map->stripe_len;
u64 offset;
u64 extent_logical;
u64 extent_physical;
/*
* Unlike chunk length, extent length should never go beyond
* BTRFS_MAX_EXTENT_SIZE, thus u32 is enough here.
*/
u32 extent_len;
u64 stripe_logical;
u64 stripe_end;
struct btrfs_device *extent_dev;
int extent_mirror_num;
int stop_loop = 0;
physical = map->stripes[num].physical;
offset = 0;
nstripes = div64_u64(length, map->stripe_len);
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
offset = map->stripe_len * num;
increment = map->stripe_len * map->num_stripes;
mirror_num = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
int factor = map->num_stripes / map->sub_stripes;
offset = map->stripe_len * (num / map->sub_stripes);
increment = map->stripe_len * factor;
mirror_num = num % map->sub_stripes + 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
increment = map->stripe_len;
mirror_num = num % map->num_stripes + 1;
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
increment = map->stripe_len;
mirror_num = num % map->num_stripes + 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
get_raid56_logic_offset(physical, num, map, &offset, NULL);
increment = map->stripe_len * nr_data_stripes(map);
mirror_num = 1;
} else {
increment = map->stripe_len;
mirror_num = 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ppath = btrfs_alloc_path();
if (!ppath) {
btrfs_free_path(path);
return -ENOMEM;
}
/*
* work on commit root. The related disk blocks are static as
* long as COW is applied. This means, it is save to rewrite
* them to repair disk errors without any race conditions
*/
path->search_commit_root = 1;
path->skip_locking = 1;
ppath->search_commit_root = 1;
ppath->skip_locking = 1;
/*
* trigger the readahead for extent tree csum tree and wait for
* completion. During readahead, the scrub is officially paused
* to not hold off transaction commits
*/
logical = base + offset;
physical_end = physical + nstripes * map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
get_raid56_logic_offset(physical_end, num,
map, &logic_end, NULL);
logic_end += base;
} else {
logic_end = logical + increment * nstripes;
}
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
scrub_blocked_if_needed(fs_info);
/* FIXME it might be better to start readahead at commit root */
key.objectid = logical;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = (u64)0;
key_end.objectid = logic_end;
key_end.type = BTRFS_METADATA_ITEM_KEY;
key_end.offset = (u64)-1;
reada1 = btrfs_reada_add(root, &key, &key_end);
if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key.type = BTRFS_EXTENT_CSUM_KEY;
key.offset = logical;
key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
key_end.type = BTRFS_EXTENT_CSUM_KEY;
key_end.offset = logic_end;
reada2 = btrfs_reada_add(csum_root, &key, &key_end);
} else {
reada2 = NULL;
}
if (!IS_ERR(reada1))
btrfs_reada_wait(reada1);
if (!IS_ERR_OR_NULL(reada2))
btrfs_reada_wait(reada2);
/*
* collect all data csums for the stripe to avoid seeking during
* the scrub. This might currently (crc32) end up to be about 1MB
*/
blk_start_plug(&plug);
/*
* now find all extents for each stripe and scrub them
*/
ret = 0;
while (physical < physical_end) {
/*
* canceled?
*/
if (atomic_read(&fs_info->scrub_cancel_req) ||
atomic_read(&sctx->cancel_req)) {
ret = -ECANCELED;
goto out;
}
/*
* check to see if we have to pause
*/
if (atomic_read(&fs_info->scrub_pause_req)) {
/* push queued extents */
sctx->flush_all_writes = true;
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
sctx->flush_all_writes = false;
scrub_blocked_if_needed(fs_info);
}
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
ret = get_raid56_logic_offset(physical, num, map,
&logical,
&stripe_logical);
logical += base;
if (ret) {
/* it is parity strip */
stripe_logical += base;
stripe_end = stripe_logical + increment;
ret = scrub_raid56_parity(sctx, map, scrub_dev,
ppath, stripe_logical,
stripe_end);
if (ret)
goto out;
goto skip;
}
}
if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
key.objectid = logical;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_extent_item(root, path, 0);
if (ret < 0)
goto out;
if (ret > 0) {
/* there's no smaller item, so stick with the
* larger one */
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &key,
path, 0, 0);
if (ret < 0)
goto out;
}
}
stop_loop = 0;
while (1) {
u64 bytes;
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
stop_loop = 1;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.type != BTRFS_EXTENT_ITEM_KEY &&
key.type != BTRFS_METADATA_ITEM_KEY)
goto next;
if (key.type == BTRFS_METADATA_ITEM_KEY)
bytes = fs_info->nodesize;
else
bytes = key.offset;
if (key.objectid + bytes <= logical)
goto next;
if (key.objectid >= logical + map->stripe_len) {
/* out of this device extent */
if (key.objectid >= logic_end)
stop_loop = 1;
break;
}
/*
* If our block group was removed in the meanwhile, just
* stop scrubbing since there is no point in continuing.
* Continuing would prevent reusing its device extents
* for new block groups for a long time.
*/
spin_lock(&cache->lock);
if (cache->removed) {
spin_unlock(&cache->lock);
ret = 0;
goto out;
}
spin_unlock(&cache->lock);
extent = btrfs_item_ptr(l, slot,
struct btrfs_extent_item);
flags = btrfs_extent_flags(l, extent);
generation = btrfs_extent_generation(l, extent);
if ((flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
(key.objectid < logical ||
key.objectid + bytes >
logical + map->stripe_len)) {
btrfs_err(fs_info,
"scrub: tree block %llu spanning stripes, ignored. logical=%llu",
key.objectid, logical);
spin_lock(&sctx->stat_lock);
sctx->stat.uncorrectable_errors++;
spin_unlock(&sctx->stat_lock);
goto next;
}
again:
extent_logical = key.objectid;
ASSERT(bytes <= U32_MAX);
extent_len = bytes;
/*
* trim extent to this stripe
*/
if (extent_logical < logical) {
extent_len -= logical - extent_logical;
extent_logical = logical;
}
if (extent_logical + extent_len >
logical + map->stripe_len) {
extent_len = logical + map->stripe_len -
extent_logical;
}
extent_physical = extent_logical - logical + physical;
extent_dev = scrub_dev;
extent_mirror_num = mirror_num;
if (sctx->is_dev_replace)
scrub_remap_extent(fs_info, extent_logical,
extent_len, &extent_physical,
&extent_dev,
&extent_mirror_num);
if (flags & BTRFS_EXTENT_FLAG_DATA) {
ret = btrfs_lookup_csums_range(csum_root,
extent_logical,
extent_logical + extent_len - 1,
&sctx->csum_list, 1);
if (ret)
goto out;
}
ret = scrub_extent(sctx, map, extent_logical, extent_len,
extent_physical, extent_dev, flags,
generation, extent_mirror_num,
extent_logical - logical + physical);
scrub_free_csums(sctx);
if (ret)
goto out;
if (extent_logical + extent_len <
key.objectid + bytes) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
/*
* loop until we find next data stripe
* or we have finished all stripes.
*/
loop:
physical += map->stripe_len;
ret = get_raid56_logic_offset(physical,
num, map, &logical,
&stripe_logical);
logical += base;
if (ret && physical < physical_end) {
stripe_logical += base;
stripe_end = stripe_logical +
increment;
ret = scrub_raid56_parity(sctx,
map, scrub_dev, ppath,
stripe_logical,
stripe_end);
if (ret)
goto out;
goto loop;
}
} else {
physical += map->stripe_len;
logical += increment;
}
if (logical < key.objectid + bytes) {
cond_resched();
goto again;
}
if (physical >= physical_end) {
stop_loop = 1;
break;
}
}
next:
path->slots[0]++;
}
btrfs_release_path(path);
skip:
logical += increment;
physical += map->stripe_len;
spin_lock(&sctx->stat_lock);
if (stop_loop)
sctx->stat.last_physical = map->stripes[num].physical +
length;
else
sctx->stat.last_physical = physical;
spin_unlock(&sctx->stat_lock);
if (stop_loop)
break;
}
out:
/* push queued extents */
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
blk_finish_plug(&plug);
btrfs_free_path(path);
btrfs_free_path(ppath);
return ret < 0 ? ret : 0;
}
static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev,
u64 chunk_offset, u64 length,
u64 dev_offset,
struct btrfs_block_group *cache)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct extent_map_tree *map_tree = &fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
int i;
int ret = 0;
read_lock(&map_tree->lock);
em = lookup_extent_mapping(map_tree, chunk_offset, 1);
read_unlock(&map_tree->lock);
if (!em) {
/*
* Might have been an unused block group deleted by the cleaner
* kthread or relocation.
*/
spin_lock(&cache->lock);
if (!cache->removed)
ret = -EINVAL;
spin_unlock(&cache->lock);
return ret;
}
map = em->map_lookup;
if (em->start != chunk_offset)
goto out;
if (em->len < length)
goto out;
for (i = 0; i < map->num_stripes; ++i) {
if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
map->stripes[i].physical == dev_offset) {
ret = scrub_stripe(sctx, map, scrub_dev, i,
chunk_offset, length, cache);
if (ret)
goto out;
}
}
out:
free_extent_map(em);
return ret;
}
static noinline_for_stack
int scrub_enumerate_chunks(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev, u64 start, u64 end)
{
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_root *root = fs_info->dev_root;
u64 length;
u64 chunk_offset;
int ret = 0;
int ro_set;
int slot;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_block_group *cache;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
path->search_commit_root = 1;
path->skip_locking = 1;
key.objectid = scrub_dev->devid;
key.offset = 0ull;
key.type = BTRFS_DEV_EXTENT_KEY;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] >=
btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
break;
if (ret > 0) {
ret = 0;
break;
}
} else {
ret = 0;
}
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &found_key, slot);
if (found_key.objectid != scrub_dev->devid)
break;
if (found_key.type != BTRFS_DEV_EXTENT_KEY)
break;
if (found_key.offset >= end)
break;
if (found_key.offset < key.offset)
break;
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
length = btrfs_dev_extent_length(l, dev_extent);
if (found_key.offset + length <= start)
goto skip;
chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
/*
* get a reference on the corresponding block group to prevent
* the chunk from going away while we scrub it
*/
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
/* some chunks are removed but not committed to disk yet,
* continue scrubbing */
if (!cache)
goto skip;
/*
* Make sure that while we are scrubbing the corresponding block
* group doesn't get its logical address and its device extents
* reused for another block group, which can possibly be of a
* different type and different profile. We do this to prevent
* false error detections and crashes due to bogus attempts to
* repair extents.
*/
spin_lock(&cache->lock);
if (cache->removed) {
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
goto skip;
}
btrfs_freeze_block_group(cache);
spin_unlock(&cache->lock);
/*
* we need call btrfs_inc_block_group_ro() with scrubs_paused,
* to avoid deadlock caused by:
* btrfs_inc_block_group_ro()
* -> btrfs_wait_for_commit()
* -> btrfs_commit_transaction()
* -> btrfs_scrub_pause()
*/
scrub_pause_on(fs_info);
/*
* Don't do chunk preallocation for scrub.
*
* This is especially important for SYSTEM bgs, or we can hit
* -EFBIG from btrfs_finish_chunk_alloc() like:
* 1. The only SYSTEM bg is marked RO.
* Since SYSTEM bg is small, that's pretty common.
* 2. New SYSTEM bg will be allocated
* Due to regular version will allocate new chunk.
* 3. New SYSTEM bg is empty and will get cleaned up
* Before cleanup really happens, it's marked RO again.
* 4. Empty SYSTEM bg get scrubbed
* We go back to 2.
*
* This can easily boost the amount of SYSTEM chunks if cleaner
* thread can't be triggered fast enough, and use up all space
* of btrfs_super_block::sys_chunk_array
*
* While for dev replace, we need to try our best to mark block
* group RO, to prevent race between:
* - Write duplication
* Contains latest data
* - Scrub copy
* Contains data from commit tree
*
* If target block group is not marked RO, nocow writes can
* be overwritten by scrub copy, causing data corruption.
* So for dev-replace, it's not allowed to continue if a block
* group is not RO.
*/
ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
if (ret == 0) {
ro_set = 1;
} else if (ret == -ENOSPC && !sctx->is_dev_replace) {
/*
* btrfs_inc_block_group_ro return -ENOSPC when it
* failed in creating new chunk for metadata.
* It is not a problem for scrub, because
* metadata are always cowed, and our scrub paused
* commit_transactions.
*/
ro_set = 0;
} else {
btrfs_warn(fs_info,
"failed setting block group ro: %d", ret);
btrfs_unfreeze_block_group(cache);
btrfs_put_block_group(cache);
scrub_pause_off(fs_info);
break;
}
/*
* Now the target block is marked RO, wait for nocow writes to
* finish before dev-replace.
* COW is fine, as COW never overwrites extents in commit tree.
*/
if (sctx->is_dev_replace) {
btrfs_wait_nocow_writers(cache);
btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start,
cache->length);
}
scrub_pause_off(fs_info);
down_write(&dev_replace->rwsem);
dev_replace->cursor_right = found_key.offset + length;
dev_replace->cursor_left = found_key.offset;
dev_replace->item_needs_writeback = 1;
up_write(&dev_replace->rwsem);
ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
found_key.offset, cache);
/*
* flush, submit all pending read and write bios, afterwards
* wait for them.
* Note that in the dev replace case, a read request causes
* write requests that are submitted in the read completion
* worker. Therefore in the current situation, it is required
* that all write requests are flushed, so that all read and
* write requests are really completed when bios_in_flight
* changes to 0.
*/
sctx->flush_all_writes = true;
scrub_submit(sctx);
mutex_lock(&sctx->wr_lock);
scrub_wr_submit(sctx);
mutex_unlock(&sctx->wr_lock);
wait_event(sctx->list_wait,
atomic_read(&sctx->bios_in_flight) == 0);
scrub_pause_on(fs_info);
/*
* must be called before we decrease @scrub_paused.
* make sure we don't block transaction commit while
* we are waiting pending workers finished.
*/
wait_event(sctx->list_wait,
atomic_read(&sctx->workers_pending) == 0);
sctx->flush_all_writes = false;
scrub_pause_off(fs_info);
down_write(&dev_replace->rwsem);
dev_replace->cursor_left = dev_replace->cursor_right;
dev_replace->item_needs_writeback = 1;
up_write(&dev_replace->rwsem);
if (ro_set)
btrfs_dec_block_group_ro(cache);
/*
* We might have prevented the cleaner kthread from deleting
* this block group if it was already unused because we raced
* and set it to RO mode first. So add it back to the unused
* list, otherwise it might not ever be deleted unless a manual
* balance is triggered or it becomes used and unused again.
*/
spin_lock(&cache->lock);
if (!cache->removed && !cache->ro && cache->reserved == 0 &&
cache->used == 0) {
spin_unlock(&cache->lock);
if (btrfs_test_opt(fs_info, DISCARD_ASYNC))
btrfs_discard_queue_work(&fs_info->discard_ctl,
cache);
else
btrfs_mark_bg_unused(cache);
} else {
spin_unlock(&cache->lock);
}
btrfs_unfreeze_block_group(cache);
btrfs_put_block_group(cache);
if (ret)
break;
if (sctx->is_dev_replace &&
atomic64_read(&dev_replace->num_write_errors) > 0) {
ret = -EIO;
break;
}
if (sctx->stat.malloc_errors > 0) {
ret = -ENOMEM;
break;
}
skip:
key.offset = found_key.offset + length;
btrfs_release_path(path);
}
btrfs_free_path(path);
return ret;
}
static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
struct btrfs_device *scrub_dev)
{
int i;
u64 bytenr;
u64 gen;
int ret;
struct btrfs_fs_info *fs_info = sctx->fs_info;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
/* Seed devices of a new filesystem has their own generation. */
if (scrub_dev->fs_devices != fs_info->fs_devices)
gen = scrub_dev->generation;
else
gen = fs_info->last_trans_committed;
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
if (bytenr + BTRFS_SUPER_INFO_SIZE >
scrub_dev->commit_total_bytes)
break;
if (!btrfs_check_super_location(scrub_dev, bytenr))
continue;
ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
NULL, bytenr);
if (ret)
return ret;
}
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
return 0;
}
static void scrub_workers_put(struct btrfs_fs_info *fs_info)
{
if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt,
&fs_info->scrub_lock)) {
struct btrfs_workqueue *scrub_workers = NULL;
struct btrfs_workqueue *scrub_wr_comp = NULL;
struct btrfs_workqueue *scrub_parity = NULL;
scrub_workers = fs_info->scrub_workers;
scrub_wr_comp = fs_info->scrub_wr_completion_workers;
scrub_parity = fs_info->scrub_parity_workers;
fs_info->scrub_workers = NULL;
fs_info->scrub_wr_completion_workers = NULL;
fs_info->scrub_parity_workers = NULL;
mutex_unlock(&fs_info->scrub_lock);
btrfs_destroy_workqueue(scrub_workers);
btrfs_destroy_workqueue(scrub_wr_comp);
btrfs_destroy_workqueue(scrub_parity);
}
}
/*
* get a reference count on fs_info->scrub_workers. start worker if necessary
*/
static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
int is_dev_replace)
{
struct btrfs_workqueue *scrub_workers = NULL;
struct btrfs_workqueue *scrub_wr_comp = NULL;
struct btrfs_workqueue *scrub_parity = NULL;
unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
int max_active = fs_info->thread_pool_size;
int ret = -ENOMEM;
if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
return 0;
scrub_workers = btrfs_alloc_workqueue(fs_info, "scrub", flags,
is_dev_replace ? 1 : max_active, 4);
if (!scrub_workers)
goto fail_scrub_workers;
scrub_wr_comp = btrfs_alloc_workqueue(fs_info, "scrubwrc", flags,
max_active, 2);
if (!scrub_wr_comp)
goto fail_scrub_wr_completion_workers;
scrub_parity = btrfs_alloc_workqueue(fs_info, "scrubparity", flags,
max_active, 2);
if (!scrub_parity)
goto fail_scrub_parity_workers;
mutex_lock(&fs_info->scrub_lock);
if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
ASSERT(fs_info->scrub_workers == NULL &&
fs_info->scrub_wr_completion_workers == NULL &&
fs_info->scrub_parity_workers == NULL);
fs_info->scrub_workers = scrub_workers;
fs_info->scrub_wr_completion_workers = scrub_wr_comp;
fs_info->scrub_parity_workers = scrub_parity;
refcount_set(&fs_info->scrub_workers_refcnt, 1);
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
/* Other thread raced in and created the workers for us */
refcount_inc(&fs_info->scrub_workers_refcnt);
mutex_unlock(&fs_info->scrub_lock);
ret = 0;
btrfs_destroy_workqueue(scrub_parity);
fail_scrub_parity_workers:
btrfs_destroy_workqueue(scrub_wr_comp);
fail_scrub_wr_completion_workers:
btrfs_destroy_workqueue(scrub_workers);
fail_scrub_workers:
return ret;
}
int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
u64 end, struct btrfs_scrub_progress *progress,
int readonly, int is_dev_replace)
{
struct scrub_ctx *sctx;
int ret;
struct btrfs_device *dev;
unsigned int nofs_flag;
if (btrfs_fs_closing(fs_info))
return -EAGAIN;
if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
/*
* in this case scrub is unable to calculate the checksum
* the way scrub is implemented. Do not handle this
* situation at all because it won't ever happen.
*/
btrfs_err(fs_info,
"scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
fs_info->nodesize,
BTRFS_STRIPE_LEN);
return -EINVAL;
}
if (fs_info->nodesize >
PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
/*
* would exhaust the array bounds of pagev member in
* struct scrub_block
*/
btrfs_err(fs_info,
"scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
fs_info->nodesize,
SCRUB_MAX_PAGES_PER_BLOCK,
fs_info->sectorsize,
SCRUB_MAX_PAGES_PER_BLOCK);
return -EINVAL;
}
/* Allocate outside of device_list_mutex */
sctx = scrub_setup_ctx(fs_info, is_dev_replace);
if (IS_ERR(sctx))
return PTR_ERR(sctx);
ret = scrub_workers_get(fs_info, is_dev_replace);
if (ret)
goto out_free_ctx;
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
!is_dev_replace)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -ENODEV;
goto out;
}
if (!is_dev_replace && !readonly &&
!test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
btrfs_err_in_rcu(fs_info,
"scrub on devid %llu: filesystem on %s is not writable",
devid, rcu_str_deref(dev->name));
ret = -EROFS;
goto out;
}
mutex_lock(&fs_info->scrub_lock);
if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -EIO;
goto out;
}
down_read(&fs_info->dev_replace.rwsem);
if (dev->scrub_ctx ||
(!is_dev_replace &&
btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
up_read(&fs_info->dev_replace.rwsem);
mutex_unlock(&fs_info->scrub_lock);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
ret = -EINPROGRESS;
goto out;
}
up_read(&fs_info->dev_replace.rwsem);
sctx->readonly = readonly;
dev->scrub_ctx = sctx;
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
/*
* checking @scrub_pause_req here, we can avoid
* race between committing transaction and scrubbing.
*/
__scrub_blocked_if_needed(fs_info);
atomic_inc(&fs_info->scrubs_running);
mutex_unlock(&fs_info->scrub_lock);
/*
* In order to avoid deadlock with reclaim when there is a transaction
* trying to pause scrub, make sure we use GFP_NOFS for all the
* allocations done at btrfs_scrub_pages() and scrub_pages_for_parity()
* invoked by our callees. The pausing request is done when the
* transaction commit starts, and it blocks the transaction until scrub
* is paused (done at specific points at scrub_stripe() or right above
* before incrementing fs_info->scrubs_running).
*/
nofs_flag = memalloc_nofs_save();
if (!is_dev_replace) {
btrfs_info(fs_info, "scrub: started on devid %llu", devid);
/*
* by holding device list mutex, we can
* kick off writing super in log tree sync.
*/
mutex_lock(&fs_info->fs_devices->device_list_mutex);
ret = scrub_supers(sctx, dev);
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
}
if (!ret)
ret = scrub_enumerate_chunks(sctx, dev, start, end);
memalloc_nofs_restore(nofs_flag);
wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
atomic_dec(&fs_info->scrubs_running);
wake_up(&fs_info->scrub_pause_wait);
wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
if (progress)
memcpy(progress, &sctx->stat, sizeof(*progress));
if (!is_dev_replace)
btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
ret ? "not finished" : "finished", devid, ret);
mutex_lock(&fs_info->scrub_lock);
dev->scrub_ctx = NULL;
mutex_unlock(&fs_info->scrub_lock);
scrub_workers_put(fs_info);
scrub_put_ctx(sctx);
return ret;
out:
scrub_workers_put(fs_info);
out_free_ctx:
scrub_free_ctx(sctx);
return ret;
}
void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
atomic_inc(&fs_info->scrub_pause_req);
while (atomic_read(&fs_info->scrubs_paused) !=
atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrubs_paused) ==
atomic_read(&fs_info->scrubs_running));
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
}
void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
{
atomic_dec(&fs_info->scrub_pause_req);
wake_up(&fs_info->scrub_pause_wait);
}
int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
{
mutex_lock(&fs_info->scrub_lock);
if (!atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&fs_info->scrub_cancel_req);
while (atomic_read(&fs_info->scrubs_running)) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
atomic_read(&fs_info->scrubs_running) == 0);
mutex_lock(&fs_info->scrub_lock);
}
atomic_dec(&fs_info->scrub_cancel_req);
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
{
struct btrfs_fs_info *fs_info = dev->fs_info;
struct scrub_ctx *sctx;
mutex_lock(&fs_info->scrub_lock);
sctx = dev->scrub_ctx;
if (!sctx) {
mutex_unlock(&fs_info->scrub_lock);
return -ENOTCONN;
}
atomic_inc(&sctx->cancel_req);
while (dev->scrub_ctx) {
mutex_unlock(&fs_info->scrub_lock);
wait_event(fs_info->scrub_pause_wait,
dev->scrub_ctx == NULL);
mutex_lock(&fs_info->scrub_lock);
}
mutex_unlock(&fs_info->scrub_lock);
return 0;
}
int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
struct btrfs_scrub_progress *progress)
{
struct btrfs_device *dev;
struct scrub_ctx *sctx = NULL;
mutex_lock(&fs_info->fs_devices->device_list_mutex);
dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
if (dev)
sctx = dev->scrub_ctx;
if (sctx)
memcpy(progress, &sctx->stat, sizeof(*progress));
mutex_unlock(&fs_info->fs_devices->device_list_mutex);
return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
}
static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
u64 extent_logical, u32 extent_len,
u64 *extent_physical,
struct btrfs_device **extent_dev,
int *extent_mirror_num)
{
u64 mapped_length;
struct btrfs_bio *bbio = NULL;
int ret;
mapped_length = extent_len;
ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
&mapped_length, &bbio, 0);
if (ret || !bbio || mapped_length < extent_len ||
!bbio->stripes[0].dev->bdev) {
btrfs_put_bbio(bbio);
return;
}
*extent_physical = bbio->stripes[0].physical;
*extent_mirror_num = bbio->mirror_num;
*extent_dev = bbio->stripes[0].dev;
btrfs_put_bbio(bbio);
}
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