Commit 9f9c2364 authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: fix locking in retry path of maybe_create_worker() 



maybe_create_worker() mismanaged locking when worker creation fails
and it has to retry.  Fix locking and simplify lock manipulation.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarYong Zhang <yong.zhang@windriver.com>
parent 083b804c

kernel/workqueue.c

+3 −5
Original line number Diff line number Diff line
@@ -1442,14 +1442,14 @@ static bool maybe_create_worker(struct global_cwq *gcwq) 
	if (!need_to_create_worker(gcwq))

		return false;

restart:

	spin_unlock_irq(&gcwq->lock);



	/* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */

	mod_timer(&gcwq->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT);



	while (true) {

		struct worker *worker;



		spin_unlock_irq(&gcwq->lock);



		worker = create_worker(gcwq, true);

		if (worker) {

			del_timer_sync(&gcwq->mayday_timer);
@@ -1462,15 +1462,13 @@ static bool maybe_create_worker(struct global_cwq *gcwq) 
		if (!need_to_create_worker(gcwq))

			break;



		spin_unlock_irq(&gcwq->lock);

		__set_current_state(TASK_INTERRUPTIBLE);

		schedule_timeout(CREATE_COOLDOWN);

		spin_lock_irq(&gcwq->lock);



		if (!need_to_create_worker(gcwq))

			break;

	}



	spin_unlock_irq(&gcwq->lock);

	del_timer_sync(&gcwq->mayday_timer);

	spin_lock_irq(&gcwq->lock);

	if (need_to_create_worker(gcwq))