[PATCH] blk: do rq_qos_exit in blk_cleanup_queue

["Wang Jianchao (Kuaishou)" <jianchao.wan9@gmail.com>]

From: Wang Jianchao <wangjianchao@kuaishou.com>

When __alloc_disk_node() failed, there will not not del_gendisk()
any more, then resource in rqos policies is leaked. Add rq_qos_exit()
into blk_cleanup_queue(). rqos is removed from the list, so needn't
to worry .exit is called twice.

Fixes: commit 8e141f9eb803 ("block: drain file system I/O on del_gendisk")
Suggested-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com>
---
 block/blk-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/block/blk-core.c b/block/blk-core.c
index d93e3bb9a769..108c7207d048 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -50,6 +50,7 @@
 #include "blk-mq-sched.h"
 #include "blk-pm.h"
 #include "blk-throttle.h"
+#include "blk-rq-qos.h"
 
 struct dentry *blk_debugfs_root;
 
@@ -322,6 +323,8 @@ void blk_cleanup_queue(struct request_queue *q)
 
 	blk_queue_flag_set(QUEUE_FLAG_DEAD, q);
 
+	rq_qos_exit(q);
+
 	blk_sync_queue(q);
 	if (queue_is_mq(q)) {
 		blk_mq_cancel_work_sync(q);
-- 
2.17.1