This is a note to let you know that I've just added the patch titled
jbd2: Drop pointless wakeup from jbd2_journal_stop()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
jbd2-drop-pointless-wakeup-from-jbd2_journal_stop.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a4129775c6479663ad5f5cbbdc61517bfe03530c
Author: Jan Kara <jack@xxxxxxx>
Date: Tue Nov 5 17:44:22 2019 +0100
jbd2: Drop pointless wakeup from jbd2_journal_stop()
[ Upstream commit 5559b2d81b51de75cb7864bb1fbb82982f7e8fff ]
When we drop last handle from a transaction and journal->j_barrier_count
> 0, jbd2_journal_stop() wakes up journal->j_wait_transaction_locked
wait queue. This looks pointless - wait for outstanding handles always
happens on journal->j_wait_updates waitqueue.
journal->j_wait_transaction_locked is used to wait for transaction state
changes and by start_this_handle() for waiting until
journal->j_barrier_count drops to 0. The first case is clearly
irrelevant here since only jbd2 thread changes transaction state. The
second case looks related but jbd2_journal_unlock_updates() is
responsible for the wakeup in this case. So just drop the wakeup.
Reviewed-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/20191105164437.32602-16-jack@xxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Stable-dep-of: f6b1a1cf1c3e ("ext4: fix use-after-free in ext4_ext_shift_extents")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index ce66dbbf0f90..6d78648392f0 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1850,11 +1850,8 @@ int jbd2_journal_stop(handle_t *handle)
* once we do this, we must not dereference transaction
* pointer again.
*/
- if (atomic_dec_and_test(&transaction->t_updates)) {
+ if (atomic_dec_and_test(&transaction->t_updates))
wake_up(&journal->j_wait_updates);
- if (journal->j_barrier_count)
- wake_up(&journal->j_wait_transaction_locked);
- }
rwsem_release(&journal->j_trans_commit_map, 1, _THIS_IP_);
