blk-mq: Provide freeze queue timeout

A driver may wish to take corrective action if queued requests do not complete within a set time. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
DX37 · Mar 2, 2017 · f91328c · f91328c
1 parent 6bae363
commit f91328c
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diff --git a/block/blk-mq.c b/block/blk-mq.c
@@ -81,6 +81,15 @@ void blk_mq_freeze_queue_wait(struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait);
 
+int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
+				     unsigned long timeout)
+{
+	return wait_event_timeout(q->mq_freeze_wq,
+					percpu_ref_is_zero(&q->q_usage_counter),
+					timeout);
+}
+EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout);
+
 /*
  * Guarantee no request is in use, so we can change any data structure of
  * the queue afterward.

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
@@ -246,6 +246,8 @@ void blk_mq_freeze_queue(struct request_queue *q);
 void blk_mq_unfreeze_queue(struct request_queue *q);
 void blk_mq_freeze_queue_start(struct request_queue *q);
 void blk_mq_freeze_queue_wait(struct request_queue *q);
+int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
+				     unsigned long timeout);
 int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);
 
 int blk_mq_map_queues(struct blk_mq_tag_set *set);