2023-05-24 11:03:44

by Jan Kara

[permalink] [raw]
Subject: [PATCH] ext4: Fix fsync for non-directories

Commit e360c6ed7274 ("ext4: Drop special handling of journalled data
from ext4_sync_file()") simplified ext4_sync_file() by dropping special
handling of journalled data mode as it was not needed anymore. However
that branch was also used for directories and symlinks and since the
fastcommit code does not track metadata changes to non-regular files, the
change has caused e.g. fsync(2) on directories to not commit transaction
as it should. Fix the problem by adding handling for non-regular files.

Fixes: e360c6ed7274 ("ext4: Drop special handling of journalled data from ext4_sync_file()")
Reported-by: Eric Whitney <[email protected]>
Link: https://lore.kernel.org/all/ZFqO3xVnmhL7zv1x@debian-BULLSEYE-live-builder-AMD64
Signed-off-by: Jan Kara <[email protected]>
---
fs/ext4/fsync.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index f65fdb27ce14..2a143209aa0c 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -108,6 +108,13 @@ static int ext4_fsync_journal(struct inode *inode, bool datasync,
journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;

+ /*
+ * Fastcommit does not really support fsync on directories or other
+ * special files. Force a full commit.
+ */
+ if (!S_ISREG(inode->i_mode))
+ return ext4_force_commit(inode->i_sb);
+
if (journal->j_flags & JBD2_BARRIER &&
!jbd2_trans_will_send_data_barrier(journal, commit_tid))
*needs_barrier = true;
--
2.35.3



2023-05-24 22:19:44

by Eric Whitney

[permalink] [raw]
Subject: Re: [PATCH] ext4: Fix fsync for non-directories

* Jan Kara <[email protected]>:
> Commit e360c6ed7274 ("ext4: Drop special handling of journalled data
> from ext4_sync_file()") simplified ext4_sync_file() by dropping special
> handling of journalled data mode as it was not needed anymore. However
> that branch was also used for directories and symlinks and since the
> fastcommit code does not track metadata changes to non-regular files, the
> change has caused e.g. fsync(2) on directories to not commit transaction
> as it should. Fix the problem by adding handling for non-regular files.
>
> Fixes: e360c6ed7274 ("ext4: Drop special handling of journalled data from ext4_sync_file()")
> Reported-by: Eric Whitney <[email protected]>
> Link: https://lore.kernel.org/all/ZFqO3xVnmhL7zv1x@debian-BULLSEYE-live-builder-AMD64
> Signed-off-by: Jan Kara <[email protected]>
> ---
> fs/ext4/fsync.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
> index f65fdb27ce14..2a143209aa0c 100644
> --- a/fs/ext4/fsync.c
> +++ b/fs/ext4/fsync.c
> @@ -108,6 +108,13 @@ static int ext4_fsync_journal(struct inode *inode, bool datasync,
> journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
> tid_t commit_tid = datasync ? ei->i_datasync_tid : ei->i_sync_tid;
>
> + /*
> + * Fastcommit does not really support fsync on directories or other
> + * special files. Force a full commit.
> + */
> + if (!S_ISREG(inode->i_mode))
> + return ext4_force_commit(inode->i_sb);
> +
> if (journal->j_flags & JBD2_BARRIER &&
> !jbd2_trans_will_send_data_barrier(journal, commit_tid))
> *needs_barrier = true;
> --
> 2.35.3
>

Hi Jan:

100/100 trials of both the original test regressions - generic/065 and
generic/535 - passed when I used kvm-xfstests to run them on a 6.4-rc3 kernel
modified with this patch. A complete run of the adv test case also passed
without new regressions.

So,
Tested-by: Eric Whitney <[email protected]>

Thanks!
Eric


2023-05-30 19:29:11

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH] ext4: Fix fsync for non-directories


On Wed, 24 May 2023 12:44:53 +0200, Jan Kara wrote:
> Commit e360c6ed7274 ("ext4: Drop special handling of journalled data
> from ext4_sync_file()") simplified ext4_sync_file() by dropping special
> handling of journalled data mode as it was not needed anymore. However
> that branch was also used for directories and symlinks and since the
> fastcommit code does not track metadata changes to non-regular files, the
> change has caused e.g. fsync(2) on directories to not commit transaction
> as it should. Fix the problem by adding handling for non-regular files.
>
> [...]

Applied, thanks!

[1/1] ext4: Fix fsync for non-directories
commit: 47a71ba09a8473c81cb87ed11421ed2896f352d2

Best regards,
--
Theodore Ts'o <[email protected]>