From: Ming Lei <ming.lei@redhat.com>
Date: Thu, 16 Nov 2017 08:08:44 +0800
Subject: [PATCH] block: wake up all tasks blocked in get_request()
References: bsc#1077989
Git-commit: 34d9715ac1edd50285168dd8d80c972739a4f6a4
Patch-mainline: v4.15-rc1

Once blk_set_queue_dying() is done in blk_cleanup_queue(), we call
blk_freeze_queue() and wait for q->q_usage_counter becoming zero. But
if there are tasks blocked in get_request(), q->q_usage_counter can
never become zero. So we have to wake up all these tasks in
blk_set_queue_dying() first.

Fixes: 3ef28e83ab157997 ("block: generic request_queue reference counting")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 block/blk-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index a886a576e63b..9ef791390990 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -606,8 +606,8 @@ void blk_set_queue_dying(struct request_queue *q)
 		spin_lock_irq(q->queue_lock);
 		blk_queue_for_each_rl(rl, q) {
 			if (rl->rq_pool) {
-				wake_up(&rl->wait[BLK_RW_SYNC]);
-				wake_up(&rl->wait[BLK_RW_ASYNC]);
+				wake_up_all(&rl->wait[BLK_RW_SYNC]);
+				wake_up_all(&rl->wait[BLK_RW_ASYNC]);
 			}
 		}
 		spin_unlock_irq(q->queue_lock);
-- 
2.12.3