From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Wed, 31 Aug 2016 22:18:11 +0000 (-0700)
Subject: dm rq: factor out dm_mq_stop_queue()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2397a15aff35b5b4eed732ce81fda5a9d15053f9;p=linux-beck.git

dm rq: factor out dm_mq_stop_queue()

Also, check that the blk-mq request_queue isn't already stopped.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 1ca7463e8bb2..2f605f62e47d 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -98,18 +98,30 @@ static void dm_old_stop_queue(struct request_queue *q)
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
+static void dm_mq_stop_queue(struct request_queue *q)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	if (blk_queue_stopped(q)) {
+		spin_unlock_irqrestore(q->queue_lock, flags);
+		return;
+	}
+
+	queue_flag_set(QUEUE_FLAG_STOPPED, q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
+	/* Avoid that requeuing could restart the queue. */
+	blk_mq_cancel_requeue_work(q);
+	blk_mq_stop_hw_queues(q);
+}
+
 void dm_stop_queue(struct request_queue *q)
 {
 	if (!q->mq_ops)
 		dm_old_stop_queue(q);
-	else {
-		spin_lock_irq(q->queue_lock);
-		queue_flag_set(QUEUE_FLAG_STOPPED, q);
-		spin_unlock_irq(q->queue_lock);
-
-		blk_mq_cancel_requeue_work(q);
-		blk_mq_stop_hw_queues(q);
-	}
+	else
+		dm_mq_stop_queue(q);
 }
 
 static struct dm_rq_target_io *alloc_old_rq_tio(struct mapped_device *md,