jbd2: Drop pointless wakeup from jbd2_journal_stop()

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 <[email protected]> Signed-off-by: Jan Kara <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>
tadfisher · Nov 5, 2019 · 5559b2d · 5559b2d
1 parent 150549e
commit 5559b2d
Showing 1 changed file with 1 addition and 4 deletions.
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
@@ -1831,11 +1831,8 @@ 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_);