From: Jan Kara Date: Tue, 6 Apr 2021 16:18:00 +0000 (+0200) Subject: ext4: annotate data race in jbd2_journal_dirty_metadata() X-Git-Tag: v5.10.79~5193 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=346190959f9750f50ae56872c17e71cda1562688;p=platform%2Fkernel%2Flinux-rpi.git ext4: annotate data race in jbd2_journal_dirty_metadata() commit 83fe6b18b8d04c6c849379005e1679bac9752466 upstream. Assertion checks in jbd2_journal_dirty_metadata() are known to be racy but we don't want to be grabbing locks just for them. We thus recheck them under b_state_lock only if it looks like they would fail. Annotate the checks with data_race(). Cc: stable@kernel.org Reported-by: Hao Sun Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20210406161804.20150-2-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 398d1d9..e8fc45f 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1479,8 +1479,8 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) * crucial to catch bugs so let's do a reliable check until the * lockless handling is fully proven. */ - if (jh->b_transaction != transaction && - jh->b_next_transaction != transaction) { + if (data_race(jh->b_transaction != transaction && + jh->b_next_transaction != transaction)) { spin_lock(&jh->b_state_lock); J_ASSERT_JH(jh, jh->b_transaction == transaction || jh->b_next_transaction == transaction); @@ -1488,8 +1488,8 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) } if (jh->b_modified == 1) { /* If it's in our transaction it must be in BJ_Metadata list. */ - if (jh->b_transaction == transaction && - jh->b_jlist != BJ_Metadata) { + if (data_race(jh->b_transaction == transaction && + jh->b_jlist != BJ_Metadata)) { spin_lock(&jh->b_state_lock); if (jh->b_transaction == transaction && jh->b_jlist != BJ_Metadata)