linux/fs/ocfs2/aops.c
Wengang Wang 1f4cea3790 ocfs2: Fail ocfs2_get_block() immediately when a block needs allocation
ocfs2_get_block() does no allocation.  Hole filling for writes should
have happened farther up in the call chain.  We detect this case and
print an error, but we then continue with the function.  We should be
exiting immediately.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-07-20 17:36:07 -07:00

1973 lines
49 KiB
C

/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* Copyright (C) 2002, 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <asm/byteorder.h>
#include <linux/swap.h>
#include <linux/pipe_fs_i.h>
#include <linux/mpage.h>
#include <linux/quotaops.h>
#define MLOG_MASK_PREFIX ML_FILE_IO
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "aops.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "suballoc.h"
#include "super.h"
#include "symlink.h"
#include "buffer_head_io.h"
static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int err = -EIO;
int status;
struct ocfs2_dinode *fe = NULL;
struct buffer_head *bh = NULL;
struct buffer_head *buffer_cache_bh = NULL;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
void *kaddr;
mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
(unsigned long long)iblock, bh_result, create);
BUG_ON(ocfs2_inode_is_fast_symlink(inode));
if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
(unsigned long long)iblock);
goto bail;
}
status = ocfs2_read_inode_block(inode, &bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
fe = (struct ocfs2_dinode *) bh->b_data;
if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
le32_to_cpu(fe->i_clusters))) {
mlog(ML_ERROR, "block offset is outside the allocated size: "
"%llu\n", (unsigned long long)iblock);
goto bail;
}
/* We don't use the page cache to create symlink data, so if
* need be, copy it over from the buffer cache. */
if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
iblock;
buffer_cache_bh = sb_getblk(osb->sb, blkno);
if (!buffer_cache_bh) {
mlog(ML_ERROR, "couldn't getblock for symlink!\n");
goto bail;
}
/* we haven't locked out transactions, so a commit
* could've happened. Since we've got a reference on
* the bh, even if it commits while we're doing the
* copy, the data is still good. */
if (buffer_jbd(buffer_cache_bh)
&& ocfs2_inode_is_new(inode)) {
kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
if (!kaddr) {
mlog(ML_ERROR, "couldn't kmap!\n");
goto bail;
}
memcpy(kaddr + (bh_result->b_size * iblock),
buffer_cache_bh->b_data,
bh_result->b_size);
kunmap_atomic(kaddr, KM_USER0);
set_buffer_uptodate(bh_result);
}
brelse(buffer_cache_bh);
}
map_bh(bh_result, inode->i_sb,
le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
err = 0;
bail:
brelse(bh);
mlog_exit(err);
return err;
}
static int ocfs2_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int err = 0;
unsigned int ext_flags;
u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
u64 p_blkno, count, past_eof;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
(unsigned long long)iblock, bh_result, create);
if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
inode, inode->i_ino);
if (S_ISLNK(inode->i_mode)) {
/* this always does I/O for some reason. */
err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
goto bail;
}
err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
&ext_flags);
if (err) {
mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
"%llu, NULL)\n", err, inode, (unsigned long long)iblock,
(unsigned long long)p_blkno);
goto bail;
}
if (max_blocks < count)
count = max_blocks;
/*
* ocfs2 never allocates in this function - the only time we
* need to use BH_New is when we're extending i_size on a file
* system which doesn't support holes, in which case BH_New
* allows block_prepare_write() to zero.
*
* If we see this on a sparse file system, then a truncate has
* raced us and removed the cluster. In this case, we clear
* the buffers dirty and uptodate bits and let the buffer code
* ignore it as a hole.
*/
if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
clear_buffer_dirty(bh_result);
clear_buffer_uptodate(bh_result);
goto bail;
}
/* Treat the unwritten extent as a hole for zeroing purposes. */
if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
map_bh(bh_result, inode->i_sb, p_blkno);
bh_result->b_size = count << inode->i_blkbits;
if (!ocfs2_sparse_alloc(osb)) {
if (p_blkno == 0) {
err = -EIO;
mlog(ML_ERROR,
"iblock = %llu p_blkno = %llu blkno=(%llu)\n",
(unsigned long long)iblock,
(unsigned long long)p_blkno,
(unsigned long long)OCFS2_I(inode)->ip_blkno);
mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
dump_stack();
goto bail;
}
past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
(unsigned long long)past_eof);
if (create && (iblock >= past_eof))
set_buffer_new(bh_result);
}
bail:
if (err < 0)
err = -EIO;
mlog_exit(err);
return err;
}
int ocfs2_read_inline_data(struct inode *inode, struct page *page,
struct buffer_head *di_bh)
{
void *kaddr;
loff_t size;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
return -EROFS;
}
size = i_size_read(inode);
if (size > PAGE_CACHE_SIZE ||
size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
ocfs2_error(inode->i_sb,
"Inode %llu has with inline data has bad size: %Lu",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)size);
return -EROFS;
}
kaddr = kmap_atomic(page, KM_USER0);
if (size)
memcpy(kaddr, di->id2.i_data.id_data, size);
/* Clear the remaining part of the page */
memset(kaddr + size, 0, PAGE_CACHE_SIZE - size);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
SetPageUptodate(page);
return 0;
}
static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
{
int ret;
struct buffer_head *di_bh = NULL;
BUG_ON(!PageLocked(page));
BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
ret = ocfs2_read_inode_block(inode, &di_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_read_inline_data(inode, page, di_bh);
out:
unlock_page(page);
brelse(di_bh);
return ret;
}
static int ocfs2_readpage(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
int ret, unlock = 1;
mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
if (ret != 0) {
if (ret == AOP_TRUNCATED_PAGE)
unlock = 0;
mlog_errno(ret);
goto out;
}
if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
ret = AOP_TRUNCATED_PAGE;
goto out_inode_unlock;
}
/*
* i_size might have just been updated as we grabed the meta lock. We
* might now be discovering a truncate that hit on another node.
* block_read_full_page->get_block freaks out if it is asked to read
* beyond the end of a file, so we check here. Callers
* (generic_file_read, vm_ops->fault) are clever enough to check i_size
* and notice that the page they just read isn't needed.
*
* XXX sys_readahead() seems to get that wrong?
*/
if (start >= i_size_read(inode)) {
zero_user(page, 0, PAGE_SIZE);
SetPageUptodate(page);
ret = 0;
goto out_alloc;
}
if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
ret = ocfs2_readpage_inline(inode, page);
else
ret = block_read_full_page(page, ocfs2_get_block);
unlock = 0;
out_alloc:
up_read(&OCFS2_I(inode)->ip_alloc_sem);
out_inode_unlock:
ocfs2_inode_unlock(inode, 0);
out:
if (unlock)
unlock_page(page);
mlog_exit(ret);
return ret;
}
/*
* This is used only for read-ahead. Failures or difficult to handle
* situations are safe to ignore.
*
* Right now, we don't bother with BH_Boundary - in-inode extent lists
* are quite large (243 extents on 4k blocks), so most inodes don't
* grow out to a tree. If need be, detecting boundary extents could
* trivially be added in a future version of ocfs2_get_block().
*/
static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
int ret, err = -EIO;
struct inode *inode = mapping->host;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
loff_t start;
struct page *last;
/*
* Use the nonblocking flag for the dlm code to avoid page
* lock inversion, but don't bother with retrying.
*/
ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
if (ret)
return err;
if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
ocfs2_inode_unlock(inode, 0);
return err;
}
/*
* Don't bother with inline-data. There isn't anything
* to read-ahead in that case anyway...
*/
if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
goto out_unlock;
/*
* Check whether a remote node truncated this file - we just
* drop out in that case as it's not worth handling here.
*/
last = list_entry(pages->prev, struct page, lru);
start = (loff_t)last->index << PAGE_CACHE_SHIFT;
if (start >= i_size_read(inode))
goto out_unlock;
err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
out_unlock:
up_read(&oi->ip_alloc_sem);
ocfs2_inode_unlock(inode, 0);
return err;
}
/* Note: Because we don't support holes, our allocation has
* already happened (allocation writes zeros to the file data)
* so we don't have to worry about ordered writes in
* ocfs2_writepage.
*
* ->writepage is called during the process of invalidating the page cache
* during blocked lock processing. It can't block on any cluster locks
* to during block mapping. It's relying on the fact that the block
* mapping can't have disappeared under the dirty pages that it is
* being asked to write back.
*/
static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
{
int ret;
mlog_entry("(0x%p)\n", page);
ret = block_write_full_page(page, ocfs2_get_block, wbc);
mlog_exit(ret);
return ret;
}
/*
* This is called from ocfs2_write_zero_page() which has handled it's
* own cluster locking and has ensured allocation exists for those
* blocks to be written.
*/
int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
unsigned from, unsigned to)
{
int ret;
ret = block_prepare_write(page, from, to, ocfs2_get_block);
return ret;
}
/* Taken from ext3. We don't necessarily need the full blown
* functionality yet, but IMHO it's better to cut and paste the whole
* thing so we can avoid introducing our own bugs (and easily pick up
* their fixes when they happen) --Mark */
int walk_page_buffers( handle_t *handle,
struct buffer_head *head,
unsigned from,
unsigned to,
int *partial,
int (*fn)( handle_t *handle,
struct buffer_head *bh))
{
struct buffer_head *bh;
unsigned block_start, block_end;
unsigned blocksize = head->b_size;
int err, ret = 0;
struct buffer_head *next;
for ( bh = head, block_start = 0;
ret == 0 && (bh != head || !block_start);
block_start = block_end, bh = next)
{
next = bh->b_this_page;
block_end = block_start + blocksize;
if (block_end <= from || block_start >= to) {
if (partial && !buffer_uptodate(bh))
*partial = 1;
continue;
}
err = (*fn)(handle, bh);
if (!ret)
ret = err;
}
return ret;
}
handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
struct page *page,
unsigned from,
unsigned to)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
handle_t *handle;
int ret = 0;
handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
if (IS_ERR(handle)) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
if (ocfs2_should_order_data(inode)) {
ret = ocfs2_jbd2_file_inode(handle, inode);
if (ret < 0)
mlog_errno(ret);
}
out:
if (ret) {
if (!IS_ERR(handle))
ocfs2_commit_trans(osb, handle);
handle = ERR_PTR(ret);
}
return handle;
}
static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
{
sector_t status;
u64 p_blkno = 0;
int err = 0;
struct inode *inode = mapping->host;
mlog_entry("(block = %llu)\n", (unsigned long long)block);
/* We don't need to lock journal system files, since they aren't
* accessed concurrently from multiple nodes.
*/
if (!INODE_JOURNAL(inode)) {
err = ocfs2_inode_lock(inode, NULL, 0);
if (err) {
if (err != -ENOENT)
mlog_errno(err);
goto bail;
}
down_read(&OCFS2_I(inode)->ip_alloc_sem);
}
if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
NULL);
if (!INODE_JOURNAL(inode)) {
up_read(&OCFS2_I(inode)->ip_alloc_sem);
ocfs2_inode_unlock(inode, 0);
}
if (err) {
mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
(unsigned long long)block);
mlog_errno(err);
goto bail;
}
bail:
status = err ? 0 : p_blkno;
mlog_exit((int)status);
return status;
}
/*
* TODO: Make this into a generic get_blocks function.
*
* From do_direct_io in direct-io.c:
* "So what we do is to permit the ->get_blocks function to populate
* bh.b_size with the size of IO which is permitted at this offset and
* this i_blkbits."
*
* This function is called directly from get_more_blocks in direct-io.c.
*
* called like this: dio->get_blocks(dio->inode, fs_startblk,
* fs_count, map_bh, dio->rw == WRITE);
*/
static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
int ret;
u64 p_blkno, inode_blocks, contig_blocks;
unsigned int ext_flags;
unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
/* This function won't even be called if the request isn't all
* nicely aligned and of the right size, so there's no need
* for us to check any of that. */
inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
/*
* Any write past EOF is not allowed because we'd be extending.
*/
if (create && (iblock + max_blocks) > inode_blocks) {
ret = -EIO;
goto bail;
}
/* This figures out the size of the next contiguous block, and
* our logical offset */
ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
&contig_blocks, &ext_flags);
if (ret) {
mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
(unsigned long long)iblock);
ret = -EIO;
goto bail;
}
if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno && create) {
ocfs2_error(inode->i_sb,
"Inode %llu has a hole at block %llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)iblock);
ret = -EROFS;
goto bail;
}
/*
* get_more_blocks() expects us to describe a hole by clearing
* the mapped bit on bh_result().
*
* Consider an unwritten extent as a hole.
*/
if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
map_bh(bh_result, inode->i_sb, p_blkno);
else {
/*
* ocfs2_prepare_inode_for_write() should have caught
* the case where we'd be filling a hole and triggered
* a buffered write instead.
*/
if (create) {
ret = -EIO;
mlog_errno(ret);
goto bail;
}
clear_buffer_mapped(bh_result);
}
/* make sure we don't map more than max_blocks blocks here as
that's all the kernel will handle at this point. */
if (max_blocks < contig_blocks)
contig_blocks = max_blocks;
bh_result->b_size = contig_blocks << blocksize_bits;
bail:
return ret;
}
/*
* ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
* particularly interested in the aio/dio case. Like the core uses
* i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
* truncation on another.
*/
static void ocfs2_dio_end_io(struct kiocb *iocb,
loff_t offset,
ssize_t bytes,
void *private)
{
struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
int level;
/* this io's submitter should not have unlocked this before we could */
BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
ocfs2_iocb_clear_rw_locked(iocb);
level = ocfs2_iocb_rw_locked_level(iocb);
if (!level)
up_read(&inode->i_alloc_sem);
ocfs2_rw_unlock(inode, level);
}
/*
* ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
* from ext3. PageChecked() bits have been removed as OCFS2 does not
* do journalled data.
*/
static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
{
journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
jbd2_journal_invalidatepage(journal, page, offset);
}
static int ocfs2_releasepage(struct page *page, gfp_t wait)
{
journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
if (!page_has_buffers(page))
return 0;
return jbd2_journal_try_to_free_buffers(journal, page, wait);
}
static ssize_t ocfs2_direct_IO(int rw,
struct kiocb *iocb,
const struct iovec *iov,
loff_t offset,
unsigned long nr_segs)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
int ret;
mlog_entry_void();
/*
* Fallback to buffered I/O if we see an inode without
* extents.
*/
if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
return 0;
ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
inode->i_sb->s_bdev, iov, offset,
nr_segs,
ocfs2_direct_IO_get_blocks,
ocfs2_dio_end_io);
mlog_exit(ret);
return ret;
}
static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
u32 cpos,
unsigned int *start,
unsigned int *end)
{
unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
unsigned int cpp;
cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
cluster_start = cpos % cpp;
cluster_start = cluster_start << osb->s_clustersize_bits;
cluster_end = cluster_start + osb->s_clustersize;
}
BUG_ON(cluster_start > PAGE_SIZE);
BUG_ON(cluster_end > PAGE_SIZE);
if (start)
*start = cluster_start;
if (end)
*end = cluster_end;
}
/*
* 'from' and 'to' are the region in the page to avoid zeroing.
*
* If pagesize > clustersize, this function will avoid zeroing outside
* of the cluster boundary.
*
* from == to == 0 is code for "zero the entire cluster region"
*/
static void ocfs2_clear_page_regions(struct page *page,
struct ocfs2_super *osb, u32 cpos,
unsigned from, unsigned to)
{
void *kaddr;
unsigned int cluster_start, cluster_end;
ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
kaddr = kmap_atomic(page, KM_USER0);
if (from || to) {
if (from > cluster_start)
memset(kaddr + cluster_start, 0, from - cluster_start);
if (to < cluster_end)
memset(kaddr + to, 0, cluster_end - to);
} else {
memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
}
kunmap_atomic(kaddr, KM_USER0);
}
/*
* Nonsparse file systems fully allocate before we get to the write
* code. This prevents ocfs2_write() from tagging the write as an
* allocating one, which means ocfs2_map_page_blocks() might try to
* read-in the blocks at the tail of our file. Avoid reading them by
* testing i_size against each block offset.
*/
static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
unsigned int block_start)
{
u64 offset = page_offset(page) + block_start;
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
return 1;
if (i_size_read(inode) > offset)
return 1;
return 0;
}
/*
* Some of this taken from block_prepare_write(). We already have our
* mapping by now though, and the entire write will be allocating or
* it won't, so not much need to use BH_New.
*
* This will also skip zeroing, which is handled externally.
*/
int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
struct inode *inode, unsigned int from,
unsigned int to, int new)
{
int ret = 0;
struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
unsigned int block_end, block_start;
unsigned int bsize = 1 << inode->i_blkbits;
if (!page_has_buffers(page))
create_empty_buffers(page, bsize, 0);
head = page_buffers(page);
for (bh = head, block_start = 0; bh != head || !block_start;
bh = bh->b_this_page, block_start += bsize) {
block_end = block_start + bsize;
clear_buffer_new(bh);
/*
* Ignore blocks outside of our i/o range -
* they may belong to unallocated clusters.
*/
if (block_start >= to || block_end <= from) {
if (PageUptodate(page))
set_buffer_uptodate(bh);
continue;
}
/*
* For an allocating write with cluster size >= page
* size, we always write the entire page.
*/
if (new)
set_buffer_new(bh);
if (!buffer_mapped(bh)) {
map_bh(bh, inode->i_sb, *p_blkno);
unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
}
if (PageUptodate(page)) {
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
!buffer_new(bh) &&
ocfs2_should_read_blk(inode, page, block_start) &&
(block_start < from || block_end > to)) {
ll_rw_block(READ, 1, &bh);
*wait_bh++=bh;
}
*p_blkno = *p_blkno + 1;
}
/*
* If we issued read requests - let them complete.
*/
while(wait_bh > wait) {
wait_on_buffer(*--wait_bh);
if (!buffer_uptodate(*wait_bh))
ret = -EIO;
}
if (ret == 0 || !new)
return ret;
/*
* If we get -EIO above, zero out any newly allocated blocks
* to avoid exposing stale data.
*/
bh = head;
block_start = 0;
do {
block_end = block_start + bsize;
if (block_end <= from)
goto next_bh;
if (block_start >= to)
break;
zero_user(page, block_start, bh->b_size);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
next_bh:
block_start = block_end;
bh = bh->b_this_page;
} while (bh != head);
return ret;
}
#if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
#define OCFS2_MAX_CTXT_PAGES 1
#else
#define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
#endif
#define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
/*
* Describe the state of a single cluster to be written to.
*/
struct ocfs2_write_cluster_desc {
u32 c_cpos;
u32 c_phys;
/*
* Give this a unique field because c_phys eventually gets
* filled.
*/
unsigned c_new;
unsigned c_unwritten;
};
static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d)
{
return d->c_new || d->c_unwritten;
}
struct ocfs2_write_ctxt {
/* Logical cluster position / len of write */
u32 w_cpos;
u32 w_clen;
struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
/*
* This is true if page_size > cluster_size.
*
* It triggers a set of special cases during write which might
* have to deal with allocating writes to partial pages.
*/
unsigned int w_large_pages;
/*
* Pages involved in this write.
*
* w_target_page is the page being written to by the user.
*
* w_pages is an array of pages which always contains
* w_target_page, and in the case of an allocating write with
* page_size < cluster size, it will contain zero'd and mapped
* pages adjacent to w_target_page which need to be written
* out in so that future reads from that region will get
* zero's.
*/
struct page *w_pages[OCFS2_MAX_CTXT_PAGES];
unsigned int w_num_pages;
struct page *w_target_page;
/*
* ocfs2_write_end() uses this to know what the real range to
* write in the target should be.
*/
unsigned int w_target_from;
unsigned int w_target_to;
/*
* We could use journal_current_handle() but this is cleaner,
* IMHO -Mark
*/
handle_t *w_handle;
struct buffer_head *w_di_bh;
struct ocfs2_cached_dealloc_ctxt w_dealloc;
};
void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
{
int i;
for(i = 0; i < num_pages; i++) {
if (pages[i]) {
unlock_page(pages[i]);
mark_page_accessed(pages[i]);
page_cache_release(pages[i]);
}
}
}
static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
{
ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
brelse(wc->w_di_bh);
kfree(wc);
}
static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
struct ocfs2_super *osb, loff_t pos,
unsigned len, struct buffer_head *di_bh)
{
u32 cend;
struct ocfs2_write_ctxt *wc;
wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
if (!wc)
return -ENOMEM;
wc->w_cpos = pos >> osb->s_clustersize_bits;
cend = (pos + len - 1) >> osb->s_clustersize_bits;
wc->w_clen = cend - wc->w_cpos + 1;
get_bh(di_bh);
wc->w_di_bh = di_bh;
if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
wc->w_large_pages = 1;
else
wc->w_large_pages = 0;
ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
*wcp = wc;
return 0;
}
/*
* If a page has any new buffers, zero them out here, and mark them uptodate
* and dirty so they'll be written out (in order to prevent uninitialised
* block data from leaking). And clear the new bit.
*/
static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
{
unsigned int block_start, block_end;
struct buffer_head *head, *bh;
BUG_ON(!PageLocked(page));
if (!page_has_buffers(page))
return;
bh = head = page_buffers(page);
block_start = 0;
do {
block_end = block_start + bh->b_size;
if (buffer_new(bh)) {
if (block_end > from && block_start < to) {
if (!PageUptodate(page)) {
unsigned start, end;
start = max(from, block_start);
end = min(to, block_end);
zero_user_segment(page, start, end);
set_buffer_uptodate(bh);
}
clear_buffer_new(bh);
mark_buffer_dirty(bh);
}
}
block_start = block_end;
bh = bh->b_this_page;
} while (bh != head);
}
/*
* Only called when we have a failure during allocating write to write
* zero's to the newly allocated region.
*/
static void ocfs2_write_failure(struct inode *inode,
struct ocfs2_write_ctxt *wc,
loff_t user_pos, unsigned user_len)
{
int i;
unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
to = user_pos + user_len;
struct page *tmppage;
ocfs2_zero_new_buffers(wc->w_target_page, from, to);
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
if (page_has_buffers(tmppage)) {
if (ocfs2_should_order_data(inode))
ocfs2_jbd2_file_inode(wc->w_handle, inode);
block_commit_write(tmppage, from, to);
}
}
}
static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
struct ocfs2_write_ctxt *wc,
struct page *page, u32 cpos,
loff_t user_pos, unsigned user_len,
int new)
{
int ret;
unsigned int map_from = 0, map_to = 0;
unsigned int cluster_start, cluster_end;
unsigned int user_data_from = 0, user_data_to = 0;
ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
&cluster_start, &cluster_end);
if (page == wc->w_target_page) {
map_from = user_pos & (PAGE_CACHE_SIZE - 1);
map_to = map_from + user_len;
if (new)
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
cluster_start, cluster_end,
new);
else
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
map_from, map_to, new);
if (ret) {
mlog_errno(ret);
goto out;
}
user_data_from = map_from;
user_data_to = map_to;
if (new) {
map_from = cluster_start;
map_to = cluster_end;
}
} else {
/*
* If we haven't allocated the new page yet, we
* shouldn't be writing it out without copying user
* data. This is likely a math error from the caller.
*/
BUG_ON(!new);
map_from = cluster_start;
map_to = cluster_end;
ret = ocfs2_map_page_blocks(page, p_blkno, inode,
cluster_start, cluster_end, new);
if (ret) {
mlog_errno(ret);
goto out;
}
}
/*
* Parts of newly allocated pages need to be zero'd.
*
* Above, we have also rewritten 'to' and 'from' - as far as
* the rest of the function is concerned, the entire cluster
* range inside of a page needs to be written.
*
* We can skip this if the page is up to date - it's already
* been zero'd from being read in as a hole.
*/
if (new && !PageUptodate(page))
ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
cpos, user_data_from, user_data_to);
flush_dcache_page(page);
out:
return ret;
}
/*
* This function will only grab one clusters worth of pages.
*/
static int ocfs2_grab_pages_for_write(struct address_space *mapping,
struct ocfs2_write_ctxt *wc,
u32 cpos, loff_t user_pos, int new,
struct page *mmap_page)
{
int ret = 0, i;
unsigned long start, target_index, index;
struct inode *inode = mapping->host;
target_index = user_pos >> PAGE_CACHE_SHIFT;
/*
* Figure out how many pages we'll be manipulating here. For
* non allocating write, we just change the one
* page. Otherwise, we'll need a whole clusters worth.
*/
if (new) {
wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
} else {
wc->w_num_pages = 1;
start = target_index;
}
for(i = 0; i < wc->w_num_pages; i++) {
index = start + i;
if (index == target_index && mmap_page) {
/*
* ocfs2_pagemkwrite() is a little different
* and wants us to directly use the page
* passed in.
*/
lock_page(mmap_page);
if (mmap_page->mapping != mapping) {
unlock_page(mmap_page);
/*
* Sanity check - the locking in
* ocfs2_pagemkwrite() should ensure
* that this code doesn't trigger.
*/
ret = -EINVAL;
mlog_errno(ret);
goto out;
}
page_cache_get(mmap_page);
wc->w_pages[i] = mmap_page;
} else {
wc->w_pages[i] = find_or_create_page(mapping, index,
GFP_NOFS);
if (!wc->w_pages[i]) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
}
if (index == target_index)
wc->w_target_page = wc->w_pages[i];
}
out:
return ret;
}
/*
* Prepare a single cluster for write one cluster into the file.
*/
static int ocfs2_write_cluster(struct address_space *mapping,
u32 phys, unsigned int unwritten,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_write_ctxt *wc, u32 cpos,
loff_t user_pos, unsigned user_len)
{
int ret, i, new, should_zero = 0;
u64 v_blkno, p_blkno;
struct inode *inode = mapping->host;
struct ocfs2_extent_tree et;
new = phys == 0 ? 1 : 0;
if (new || unwritten)
should_zero = 1;
if (new) {
u32 tmp_pos;
/*
* This is safe to call with the page locks - it won't take
* any additional semaphores or cluster locks.
*/
tmp_pos = cpos;
ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
&tmp_pos, 1, 0, wc->w_di_bh,
wc->w_handle, data_ac,
meta_ac, NULL);
/*
* This shouldn't happen because we must have already
* calculated the correct meta data allocation required. The
* internal tree allocation code should know how to increase
* transaction credits itself.
*
* If need be, we could handle -EAGAIN for a
* RESTART_TRANS here.
*/
mlog_bug_on_msg(ret == -EAGAIN,
"Inode %llu: EAGAIN return during allocation.\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
} else if (unwritten) {
ocfs2_init_dinode_extent_tree(&et, inode, wc->w_di_bh);
ret = ocfs2_mark_extent_written(inode, &et,
wc->w_handle, cpos, 1, phys,
meta_ac, &wc->w_dealloc);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
if (should_zero)
v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
else
v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
/*
* The only reason this should fail is due to an inability to
* find the extent added.
*/
ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
NULL);
if (ret < 0) {
ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
"at logical block %llu",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)v_blkno);
goto out;
}
BUG_ON(p_blkno == 0);
for(i = 0; i < wc->w_num_pages; i++) {
int tmpret;
tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
wc->w_pages[i], cpos,
user_pos, user_len,
should_zero);
if (tmpret) {
mlog_errno(tmpret);
if (ret == 0)
ret = tmpret;
}
}
/*
* We only have cleanup to do in case of allocating write.
*/
if (ret && new)
ocfs2_write_failure(inode, wc, user_pos, user_len);
out:
return ret;
}
static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
struct ocfs2_alloc_context *data_ac,
struct ocfs2_alloc_context *meta_ac,
struct ocfs2_write_ctxt *wc,
loff_t pos, unsigned len)
{
int ret, i;
loff_t cluster_off;
unsigned int local_len = len;
struct ocfs2_write_cluster_desc *desc;
struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
for (i = 0; i < wc->w_clen; i++) {
desc = &wc->w_desc[i];
/*
* We have to make sure that the total write passed in
* doesn't extend past a single cluster.
*/
local_len = len;
cluster_off = pos & (osb->s_clustersize - 1);
if ((cluster_off + local_len) > osb->s_clustersize)
local_len = osb->s_clustersize - cluster_off;
ret = ocfs2_write_cluster(mapping, desc->c_phys,
desc->c_unwritten, data_ac, meta_ac,
wc, desc->c_cpos, pos, local_len);
if (ret) {
mlog_errno(ret);
goto out;
}
len -= local_len;
pos += local_len;
}
ret = 0;
out:
return ret;
}
/*
* ocfs2_write_end() wants to know which parts of the target page it
* should complete the write on. It's easiest to compute them ahead of
* time when a more complete view of the write is available.
*/
static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
struct ocfs2_write_ctxt *wc,
loff_t pos, unsigned len, int alloc)
{
struct ocfs2_write_cluster_desc *desc;
wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
wc->w_target_to = wc->w_target_from + len;
if (alloc == 0)
return;
/*
* Allocating write - we may have different boundaries based
* on page size and cluster size.
*
* NOTE: We can no longer compute one value from the other as
* the actual write length and user provided length may be
* different.
*/
if (wc->w_large_pages) {
/*
* We only care about the 1st and last cluster within
* our range and whether they should be zero'd or not. Either
* value may be extended out to the start/end of a
* newly allocated cluster.
*/
desc = &wc->w_desc[0];
if (ocfs2_should_zero_cluster(desc))
ocfs2_figure_cluster_boundaries(osb,
desc->c_cpos,
&wc->w_target_from,
NULL);
desc = &wc->w_desc[wc->w_clen - 1];
if (ocfs2_should_zero_cluster(desc))
ocfs2_figure_cluster_boundaries(osb,
desc->c_cpos,
NULL,
&wc->w_target_to);
} else {
wc->w_target_from = 0;
wc->w_target_to = PAGE_CACHE_SIZE;
}
}
/*
* Populate each single-cluster write descriptor in the write context
* with information about the i/o to be done.
*
* Returns the number of clusters that will have to be allocated, as
* well as a worst case estimate of the number of extent records that
* would have to be created during a write to an unwritten region.
*/
static int ocfs2_populate_write_desc(struct inode *inode,
struct ocfs2_write_ctxt *wc,
unsigned int *clusters_to_alloc,
unsigned int *extents_to_split)
{
int ret;
struct ocfs2_write_cluster_desc *desc;
unsigned int num_clusters = 0;
unsigned int ext_flags = 0;
u32 phys = 0;
int i;
*clusters_to_alloc = 0;
*extents_to_split = 0;
for (i = 0; i < wc->w_clen; i++) {
desc = &wc->w_desc[i];
desc->c_cpos = wc->w_cpos + i;
if (num_clusters == 0) {
/*
* Need to look up the next extent record.
*/
ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
&num_clusters, &ext_flags);
if (ret) {
mlog_errno(ret);
goto out;
}
/*
* Assume worst case - that we're writing in
* the middle of the extent.
*
* We can assume that the write proceeds from
* left to right, in which case the extent
* insert code is smart enough to coalesce the
* next splits into the previous records created.
*/
if (ext_flags & OCFS2_EXT_UNWRITTEN)
*extents_to_split = *extents_to_split + 2;
} else if (phys) {
/*
* Only increment phys if it doesn't describe
* a hole.
*/
phys++;
}
desc->c_phys = phys;
if (phys == 0) {
desc->c_new = 1;
*clusters_to_alloc = *clusters_to_alloc + 1;
}
if (ext_flags & OCFS2_EXT_UNWRITTEN)
desc->c_unwritten = 1;
num_clusters--;
}
ret = 0;
out:
return ret;
}
static int ocfs2_write_begin_inline(struct address_space *mapping,
struct inode *inode,
struct ocfs2_write_ctxt *wc)
{
int ret;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct page *page;
handle_t *handle;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
page = find_or_create_page(mapping, 0, GFP_NOFS);
if (!page) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
/*
* If we don't set w_num_pages then this page won't get unlocked
* and freed on cleanup of the write context.
*/
wc->w_pages[0] = wc->w_target_page = page;
wc->w_num_pages = 1;
handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out;
}
ret = ocfs2_journal_access_di(handle, inode, wc->w_di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
ocfs2_commit_trans(osb, handle);
mlog_errno(ret);
goto out;
}
if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
ocfs2_set_inode_data_inline(inode, di);
if (!PageUptodate(page)) {
ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
if (ret) {
ocfs2_commit_trans(osb, handle);
goto out;
}
}
wc->w_handle = handle;
out:
return ret;
}
int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
{
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
return 1;
return 0;
}
static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
struct inode *inode, loff_t pos,
unsigned len, struct page *mmap_page,
struct ocfs2_write_ctxt *wc)
{
int ret, written = 0;
loff_t end = pos + len;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_dinode *di = NULL;
mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n",
(unsigned long long)oi->ip_blkno, len, (unsigned long long)pos,
oi->ip_dyn_features);
/*
* Handle inodes which already have inline data 1st.
*/
if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
if (mmap_page == NULL &&
ocfs2_size_fits_inline_data(wc->w_di_bh, end))
goto do_inline_write;
/*
* The write won't fit - we have to give this inode an
* inline extent list now.
*/
ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
if (ret)
mlog_errno(ret);
goto out;
}
/*
* Check whether the inode can accept inline data.
*/
if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
return 0;
/*
* Check whether the write can fit.
*/
di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
if (mmap_page ||
end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
return 0;
do_inline_write:
ret = ocfs2_write_begin_inline(mapping, inode, wc);
if (ret) {
mlog_errno(ret);
goto out;
}
/*
* This signals to the caller that the data can be written
* inline.
*/
written = 1;
out:
return written ? written : ret;
}
/*
* This function only does anything for file systems which can't
* handle sparse files.
*
* What we want to do here is fill in any hole between the current end
* of allocation and the end of our write. That way the rest of the
* write path can treat it as an non-allocating write, which has no
* special case code for sparse/nonsparse files.
*/
static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos,
unsigned len,
struct ocfs2_write_ctxt *wc)
{
int ret;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
loff_t newsize = pos + len;
if (ocfs2_sparse_alloc(osb))
return 0;
if (newsize <= i_size_read(inode))
return 0;
ret = ocfs2_extend_no_holes(inode, newsize, newsize - len);
if (ret)
mlog_errno(ret);
return ret;
}
int ocfs2_write_begin_nolock(struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata,
struct buffer_head *di_bh, struct page *mmap_page)
{
int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
unsigned int clusters_to_alloc, extents_to_split;
struct ocfs2_write_ctxt *wc;
struct inode *inode = mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_dinode *di;
struct ocfs2_alloc_context *data_ac = NULL;
struct ocfs2_alloc_context *meta_ac = NULL;
handle_t *handle;
struct ocfs2_extent_tree et;
ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
if (ret) {
mlog_errno(ret);
return ret;
}
if (ocfs2_supports_inline_data(osb)) {
ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
mmap_page, wc);
if (ret == 1) {
ret = 0;
goto success;
}
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
&extents_to_split);
if (ret) {
mlog_errno(ret);
goto out;
}
di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
/*
* We set w_target_from, w_target_to here so that
* ocfs2_write_end() knows which range in the target page to
* write out. An allocation requires that we write the entire
* cluster range.
*/
if (clusters_to_alloc || extents_to_split) {
/*
* XXX: We are stretching the limits of
* ocfs2_lock_allocators(). It greatly over-estimates
* the work to be done.
*/
mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u,"
" clusters_to_add = %u, extents_to_split = %u\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(long long)i_size_read(inode), le32_to_cpu(di->i_clusters),
clusters_to_alloc, extents_to_split);
ocfs2_init_dinode_extent_tree(&et, inode, wc->w_di_bh);
ret = ocfs2_lock_allocators(inode, &et,
clusters_to_alloc, extents_to_split,
&data_ac, &meta_ac);
if (ret) {
mlog_errno(ret);
goto out;
}
credits = ocfs2_calc_extend_credits(inode->i_sb,
&di->id2.i_list,
clusters_to_alloc);
}
ocfs2_set_target_boundaries(osb, wc, pos, len,
clusters_to_alloc + extents_to_split);
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
goto out;
}
wc->w_handle = handle;
if (clusters_to_alloc && vfs_dq_alloc_space_nodirty(inode,
ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc))) {
ret = -EDQUOT;
goto out_commit;
}
/*
* We don't want this to fail in ocfs2_write_end(), so do it
* here.
*/
ret = ocfs2_journal_access_di(handle, inode, wc->w_di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out_quota;
}
/*
* Fill our page array first. That way we've grabbed enough so
* that we can zero and flush if we error after adding the
* extent.
*/
ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
clusters_to_alloc + extents_to_split,
mmap_page);
if (ret) {
mlog_errno(ret);
goto out_quota;
}
ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
len);
if (ret) {
mlog_errno(ret);
goto out_quota;
}
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
success:
*pagep = wc->w_target_page;
*fsdata = wc;
return 0;
out_quota:
if (clusters_to_alloc)
vfs_dq_free_space(inode,
ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
out_commit:
ocfs2_commit_trans(osb, handle);
out:
ocfs2_free_write_ctxt(wc);
if (data_ac)
ocfs2_free_alloc_context(data_ac);
if (meta_ac)
ocfs2_free_alloc_context(meta_ac);
return ret;
}
static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
struct buffer_head *di_bh = NULL;
struct inode *inode = mapping->host;
ret = ocfs2_inode_lock(inode, &di_bh, 1);
if (ret) {
mlog_errno(ret);
return ret;
}
/*
* Take alloc sem here to prevent concurrent lookups. That way
* the mapping, zeroing and tree manipulation within
* ocfs2_write() will be safe against ->readpage(). This
* should also serve to lock out allocation from a shared
* writeable region.
*/
down_write(&OCFS2_I(inode)->ip_alloc_sem);
ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
fsdata, di_bh, NULL);
if (ret) {
mlog_errno(ret);
goto out_fail;
}
brelse(di_bh);
return 0;
out_fail:
up_write(&OCFS2_I(inode)->ip_alloc_sem);
brelse(di_bh);
ocfs2_inode_unlock(inode, 1);
return ret;
}
static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
unsigned len, unsigned *copied,
struct ocfs2_dinode *di,
struct ocfs2_write_ctxt *wc)
{
void *kaddr;
if (unlikely(*copied < len)) {
if (!PageUptodate(wc->w_target_page)) {
*copied = 0;
return;
}
}
kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
kunmap_atomic(kaddr, KM_USER0);
mlog(0, "Data written to inode at offset %llu. "
"id_count = %u, copied = %u, i_dyn_features = 0x%x\n",
(unsigned long long)pos, *copied,
le16_to_cpu(di->id2.i_data.id_count),
le16_to_cpu(di->i_dyn_features));
}
int ocfs2_write_end_nolock(struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
int i;
unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
struct inode *inode = mapping->host;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct ocfs2_write_ctxt *wc = fsdata;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
handle_t *handle = wc->w_handle;
struct page *tmppage;
if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
goto out_write_size;
}
if (unlikely(copied < len)) {
if (!PageUptodate(wc->w_target_page))
copied = 0;
ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
start+len);
}
flush_dcache_page(wc->w_target_page);
for(i = 0; i < wc->w_num_pages; i++) {
tmppage = wc->w_pages[i];
if (tmppage == wc->w_target_page) {
from = wc->w_target_from;
to = wc->w_target_to;
BUG_ON(from > PAGE_CACHE_SIZE ||
to > PAGE_CACHE_SIZE ||
to < from);
} else {
/*
* Pages adjacent to the target (if any) imply
* a hole-filling write in which case we want
* to flush their entire range.
*/
from = 0;
to = PAGE_CACHE_SIZE;
}
if (page_has_buffers(tmppage)) {
if (ocfs2_should_order_data(inode))
ocfs2_jbd2_file_inode(wc->w_handle, inode);
block_commit_write(tmppage, from, to);
}
}
out_write_size:
pos += copied;
if (pos > inode->i_size) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
}
inode->i_blocks = ocfs2_inode_sector_count(inode);
di->i_size = cpu_to_le64((u64)i_size_read(inode));
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
ocfs2_journal_dirty(handle, wc->w_di_bh);
ocfs2_commit_trans(osb, handle);
ocfs2_run_deallocs(osb, &wc->w_dealloc);
ocfs2_free_write_ctxt(wc);
return copied;
}
static int ocfs2_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
int ret;
struct inode *inode = mapping->host;
ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
up_write(&OCFS2_I(inode)->ip_alloc_sem);
ocfs2_inode_unlock(inode, 1);
return ret;
}
const struct address_space_operations ocfs2_aops = {
.readpage = ocfs2_readpage,
.readpages = ocfs2_readpages,
.writepage = ocfs2_writepage,
.write_begin = ocfs2_write_begin,
.write_end = ocfs2_write_end,
.bmap = ocfs2_bmap,
.sync_page = block_sync_page,
.direct_IO = ocfs2_direct_IO,
.invalidatepage = ocfs2_invalidatepage,
.releasepage = ocfs2_releasepage,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
};