[PATCH] block: don't call blk_mq_run_hw_queues() for dead or dying queues

[Hannes Reinecke <hare@suse.de>]

When a queue is dying or dead there is no point in calling
blk_mq_run_hw_queues() in blk_mq_unquiesce_queue(); in fact, doing
so might crash the machine as the queue structures are in the
process of being deleted.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-mq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index a9c181603cbd..b1eeba38bc79 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -258,7 +258,8 @@ void blk_mq_unquiesce_queue(struct request_queue *q)
 	blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
 
 	/* dispatch requests which are inserted during quiescing */
-	blk_mq_run_hw_queues(q, true);
+	if (!blk_queue_dying(q) && !blk_queue_dead(q))
+		blk_mq_run_hw_queues(q, true);
 }
 EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
 
-- 
2.16.4