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ext3: Fix fsync error handling after filesystem abort.

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If filesystem was aborted we will return success
due to (sb->s_flags & MS_RDONLY) which is incorrect and
results in data loss.
In order to handle fs abort correctly we have to check
fs state once we discover that it is in MS_RDONLY state

Test case: http://patchwork.ozlabs.org/patch/244297/
Changes from V1:
 - fix spelling
 - fix smp_rmb()/debug order

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Dmitry Monakhov 2013-05-28 13:19:01 +04:00 committed by Jan Kara
parent a1457c0ce9
commit 3df3219651
2 changed files with 18 additions and 3 deletions
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8
fs/ext3/fsync.c
View file

@ -48,9 +48,13 @@ int ext3_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
trace_ext3_sync_file_enter(file, datasync);
if (inode->i_sb->s_flags & MS_RDONLY)
if (inode->i_sb->s_flags & MS_RDONLY) {
/* Make sure that we read updated state */
smp_rmb();
if (EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS)
return -EROFS;
return 0;
}
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (ret)
goto out;

13
fs/ext3/super.c
View file

@ -174,6 +174,11 @@ static void ext3_handle_error(struct super_block *sb)
if (test_opt (sb, ERRORS_RO)) {
ext3_msg(sb, KERN_CRIT,
"error: remounting filesystem read-only");
/*
* Make sure updated value of ->s_mount_state will be visible
* before ->s_flags update.
*/
smp_wmb();
sb->s_flags |= MS_RDONLY;
}
ext3_commit_super(sb, es, 1);
@ -291,8 +296,14 @@ void ext3_abort(struct super_block *sb, const char *function,
ext3_msg(sb, KERN_CRIT,
"error: remounting filesystem read-only");
EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
sb->s_flags |= MS_RDONLY;
set_opt(EXT3_SB(sb)->s_mount_opt, ABORT);
/*
* Make sure updated value of ->s_mount_state will be visible
* before ->s_flags update.
*/
smp_wmb();
sb->s_flags |= MS_RDONLY;
if (EXT3_SB(sb)->s_journal)
journal_abort(EXT3_SB(sb)->s_journal, -EIO);
}