btrfs: always choose work from prio_head first (51b98eff) · Commits · 戴 / test

In case we do not refill, we can overwrite cur pointer from prio_head by one from not prioritized head, what looks as something that was not intended. This change make we always take works from prio_head first until it's not empty. Signed-off-by:

Stanislaw Gruszka <stf_xl@wp.pl> Signed-off-by:

Josef Bacik <jbacik@fb.com>

fs/btrfs/async-thread.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -262,18 +262,19 @@ static struct btrfs_work get_next_work(struct btrfs_worker_thread worker,
		struct btrfs_work *work = NULL;
		struct list_head *cur = NULL;

		if (!list_empty(prio_head))
		if (!list_empty(prio_head)) {
		cur = prio_head->next;
		goto out;
		}

		smp_mb();
		if (!list_empty(&worker->prio_pending))
		goto refill;

		if (!list_empty(head))
		if (!list_empty(head)) {
		cur = head->next;

		if (cur)
		goto out;
		}

		refill:
		spin_lock_irq(&worker->lock);

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