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| author | Luis Henriques (SUSE) <luis.henriques@linux.dev> | 2024-07-17 18:22:20 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2024-08-26 21:21:10 -0400 |
| commit | 6db3c1575a750fd417a70e0178bdf6efa0dd5037 (patch) | |
| tree | bb5cf3895208909185b642188839af761252154c /fs | |
| parent | 0ce160c5bdb67081a62293028dc85758a8efb22a (diff) | |
| download | linux-6db3c1575a750fd417a70e0178bdf6efa0dd5037.tar.gz linux-6db3c1575a750fd417a70e0178bdf6efa0dd5037.tar.bz2 linux-6db3c1575a750fd417a70e0178bdf6efa0dd5037.zip | |
ext4: fix fast commit inode enqueueing during a full journal commit
When a full journal commit is on-going, any fast commit has to be enqueued
into a different queue: FC_Q_STAGING instead of FC_Q_MAIN. This enqueueing
is done only once, i.e. if an inode is already queued in a previous fast
commit entry it won't be enqueued again. However, if a full commit starts
_after_ the inode is enqueued into FC_Q_MAIN, the next fast commit needs to
be done into FC_Q_STAGING. And this is not being done in function
ext4_fc_track_template().
This patch fixes the issue by re-enqueuing an inode into the STAGING queue
during the fast commit clean-up callback when doing a full commit. However,
to prevent a race with a fast-commit, the clean-up callback has to be called
with the journal locked.
This bug was found using fstest generic/047. This test creates several 32k
bytes files, sync'ing each of them after it's creation, and then shutting
down the filesystem. Some data may be loss in this operation; for example a
file may have it's size truncated to zero.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240717172220.14201-1-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/fast_commit.c | 15 | ||||
| -rw-r--r-- | fs/jbd2/journal.c | 2 |
2 files changed, 15 insertions, 2 deletions
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c index 3926a05eceee..df71fd5b1fed 100644 --- a/fs/ext4/fast_commit.c +++ b/fs/ext4/fast_commit.c @@ -1288,8 +1288,21 @@ static void ext4_fc_cleanup(journal_t *journal, int full, tid_t tid) list_del_init(&iter->i_fc_list); ext4_clear_inode_state(&iter->vfs_inode, EXT4_STATE_FC_COMMITTING); - if (tid_geq(tid, iter->i_sync_tid)) + if (tid_geq(tid, iter->i_sync_tid)) { ext4_fc_reset_inode(&iter->vfs_inode); + } else if (full) { + /* + * We are called after a full commit, inode has been + * modified while the commit was running. Re-enqueue + * the inode into STAGING, which will then be splice + * back into MAIN. This cannot happen during + * fastcommit because the journal is locked all the + * time in that case (and tid doesn't increase so + * tid check above isn't reliable). + */ + list_add_tail(&EXT4_I(&iter->vfs_inode)->i_fc_list, + &sbi->s_fc_q[FC_Q_STAGING]); + } /* Make sure EXT4_STATE_FC_COMMITTING bit is clear */ smp_mb(); #if (BITS_PER_LONG < 64) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 1ebf2393bfb7..291a431f8aaf 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -740,9 +740,9 @@ EXPORT_SYMBOL(jbd2_fc_begin_commit); */ static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback) { - jbd2_journal_unlock_updates(journal); if (journal->j_fc_cleanup_callback) journal->j_fc_cleanup_callback(journal, 0, tid); + jbd2_journal_unlock_updates(journal); write_lock(&journal->j_state_lock); journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING; if (fallback) |