[PATCH 4.9 131/148] block: wake up all tasks blocked in get_request()

Greg Kroah-Hartman
2017-12-12T13:07:24Z

From: Ming Lei <ming.lei@redhat.com>

[ Upstream commit 34d9715ac1edd50285168dd8d80c972739a4f6a4 ]

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: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
block/blk-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -527,8 +527,8 @@ void blk_set_queue_dying(struct request_

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]);
}
}
}