null_blk: use async queue restart helper (48cc661e) · Commits · 戴 / test

If null_blk is run in NULL_IRQ_TIMER mode and with queue_mode NULL_Q_RQ, we need to restart the queue from the hrtimer interrupt. We can't directly invoke the request_fn from that context, so punt the queue run to async kblockd context. Tested-by:

Rabin Vincent <rabin@rab.in> Signed-off-by:

Jens Axboe <axboe@fb.com>

drivers/block/null_blk.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -232,20 +232,19 @@ static void end_cmd(struct nullb_cmd *cmd)
		break;
		case NULL_Q_BIO:
		bio_endio(cmd->bio);
		goto free_cmd;
		break;
		}

		free_cmd(cmd);

		/* Restart queue if needed, as we are freeing a tag */
		if (q && !q->mq_ops && blk_queue_stopped(q)) {
		if (queue_mode == NULL_Q_RQ && blk_queue_stopped(q)) {
		unsigned long flags;

		spin_lock_irqsave(q->queue_lock, flags);
		if (blk_queue_stopped(q))
		blk_start_queue(q);
		blk_start_queue_async(q);
		spin_unlock_irqrestore(q->queue_lock, flags);
		}
		free_cmd:
		free_cmd(cmd);
		}

		static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)

Admin message