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f2fs: fix fdatasync

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For below two cases, we can't guarantee data consistence:

a)
1. xfs_io "pwrite 0 4195328" "fsync"
2. xfs_io "pwrite 4195328 1024" "fdatasync"
3. godown
4. umount & mount
--> isize we updated before fdatasync won't be recovered

b)
1. xfs_io "pwrite -S 0xcc 0 4202496" "fsync"
2. xfs_io "fpunch 4194304 4096" "fdatasync"
3. godown
4. umount & mount
--> dnode we punched before fdatasync won't be recovered

The reason is that normally fdatasync won't be aware of modification
of metadata in file, e.g. isize changing, dnode updating, so in ->fsync
we will skip flushing node pages for above cases, result in making
fdatasynced file being lost during recovery.

Currently we have introduced DIRTY_META global list in sbi for tracking
dirty inode selectively, so in fdatasync we can choose to flush nodes
depend on dirty state of current inode in the list.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2016-11-17 20:53:31 +08:00 committed by Jaegeuk Kim
parent 04d47e6738
commit 281518c694
2 changed files with 11 additions and 2 deletions
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11
fs/f2fs/f2fs.h
View File

@ -1710,8 +1710,17 @@ static inline void f2fs_i_size_write(struct inode *inode, loff_t i_size)
set_inode_flag(inode, FI_AUTO_RECOVER);
}
static inline bool f2fs_skip_inode_update(struct inode *inode)
static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync)
{
if (dsync) {
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
bool ret;
spin_lock(&sbi->inode_lock[DIRTY_META]);
ret = list_empty(&F2FS_I(inode)->gdirty_list);
spin_unlock(&sbi->inode_lock[DIRTY_META]);
return ret;
}
if (!is_inode_flag_set(inode, FI_AUTO_RECOVER))
return false;
return F2FS_I(inode)->last_disk_size == i_size_read(inode);

2
fs/f2fs/file.c
View File

@ -208,7 +208,7 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
}
/* if the inode is dirty, let's recover all the time */
if (!datasync && !f2fs_skip_inode_update(inode)) {
if (!f2fs_skip_inode_update(inode, datasync)) {
f2fs_write_inode(inode, NULL);
goto go_write;
}