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| author | Dmitry Monakhov <dmonakhov@openvz.org> | 2013-05-28 13:19:01 +0400 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2013-07-04 19:22:55 +0200 |
| commit | 3df32196519d1556b8851b610ca1aa68c5b673d3 (patch) | |
| tree | 4d94cec2052684e7b2a27ca4769654aceca2ca9e /fs/ext3 | |
| parent | a1457c0ce976bad1356b9b0437f2a5c3ab8a9cfc (diff) | |
| download | lwn-3df32196519d1556b8851b610ca1aa68c5b673d3.tar.gz lwn-3df32196519d1556b8851b610ca1aa68c5b673d3.zip | |
ext3: Fix fsync error handling after filesystem abort.
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>
Diffstat (limited to 'fs/ext3')
| -rw-r--r-- | fs/ext3/fsync.c | 8 | ||||
| -rw-r--r-- | fs/ext3/super.c | 13 |
2 files changed, 18 insertions, 3 deletions
diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c index b31dbd4c46ad..1cb9c7e10c6f 100644 --- a/fs/ext3/fsync.c +++ b/fs/ext3/fsync.c @@ -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; diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 6356665a74bb..c47f14750722 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -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); } |