From: Jan Kara jack@suse.cz
mainline inclusion from mainline-5.5-rc1 commit 5559b2d81b51de75cb7864bb1fbb82982f7e8fff category: bugfix bugzilla: 25031 CVE: NA ---------------------------
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@mit.edu Signed-off-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20191105164437.32602-16-jack@suse.cz Signed-off-by: Theodore Ts'o tytso@mit.edu
Signed-off-by: zhangyi (F) yi.zhang@huawei.com Reviewed-by: Yang Erkun yangerkun@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/jbd2/transaction.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 9697fb3..e2184f2 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -1797,11 +1797,8 @@ 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_);