blk-mq: update comments on blk_mq_quiesce_queue() (69e07c4a) · Commits · 戴 / test

Actually what we want to get from blk_mq_quiesce_queue() isn't only to wait for completion of all ongoing .queue_rq(). In the typical context of canceling requests, we need to make sure that the following is done in the dispatch path before starting to cancel requests: - failed dispatched request is finished - busy dispatched request is requeued, and the STARTED flag is cleared So update comment to keep code, doc and our expection consistent. Signed-off-by:

Ming Lei <ming.lei@redhat.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -155,12 +155,13 @@ void blk_mq_unfreeze_queue(struct request_queue *q)
		EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);

		/**
		* blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished
		* blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished
		* @q: request queue.
		*
		* Note: this function does not prevent that the struct request end_io()
		* callback function is invoked. Additionally, it is not prevented that
		* new queue_rq() calls occur unless the queue has been stopped first.
		* callback function is invoked. Once this function is returned, we make
		* sure no dispatch can happen until the queue is unquiesced via
		* blk_mq_unquiesce_queue().
		*/
		void blk_mq_quiesce_queue(struct request_queue *q)
		{

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