On 11/15/2017 05:08 PM, Ming Lei wrote:

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.

Looks correct to me, since we do exclusive waits on that waitqueue.
Applied for this series.

Fixes: 3ef28e83ab157997(block: generic request_queue reference counting)

Note that the format here is ("patch title")

-- 
Jens Axboe