This is a note to let you know that I've just added the patch titled block: wake up all tasks blocked in get_request() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: block-wake-up-all-tasks-blocked-in-get_request.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Dec 12 13:38:50 CET 2017 From: Ming Lei <ming.lei@xxxxxxxxxx> Date: Thu, 16 Nov 2017 08:08:44 +0800 Subject: block: wake up all tasks blocked in get_request() From: Ming Lei <ming.lei@xxxxxxxxxx> [ 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@xxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/blk-core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/block/blk-core.c +++ b/block/blk-core.c @@ -526,8 +526,8 @@ 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]); } } } Patches currently in stable-queue which might be from ming.lei@xxxxxxxxxx are queue-4.4/block-wake-up-all-tasks-blocked-in-get_request.patch