[PATCH V2 2/2] block: drain blkcg part of request_queue in blk_cleanup_queue()

[Ming Lei <ming.lei@redhat.com>]

Now once blk_freeze_queue() returns, all requests(in-queue and pending)
can be drained, but we still need to drain blkcg part of request_queue
for both blk-mq and legacy, so this patch calls blkcg_drain_queue()
explicitely in blk_cleanup_queue() to do that.

Then the __blk_drain_queue() in blk_cleanup_queue() can be covered by both
blk_freeze_queue() and blkcg_drain_queue(), and tasks blocked in get_request()
are waken up in blk_set_queue_dying() too, so remove it from blk_cleanup_queue().

Cc: Wen Xiong <wenxiong@us.ibm.com>
Cc: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 block/blk-core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 1038706edd87..f3f6f11a5b31 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -689,8 +689,7 @@ void blk_cleanup_queue(struct request_queue *q)
 	 */
 	blk_freeze_queue(q);
 	spin_lock_irq(lock);
-	if (!q->mq_ops)
-		__blk_drain_queue(q, true);
+	blkcg_drain_queue(q);
 	queue_flag_set(QUEUE_FLAG_DEAD, q);
 	spin_unlock_irq(lock);
 
-- 
2.9.5