On Mon, 2017-06-05 at 23:59 +0800, Ming Lei wrote:

+/*
+ * We do not guarantee that dispatch can be drained or blocked
+ * after blk_mq_stop_hw_queue() returns. Please use
+ * blk_mq_quiesce_queue() for that requirement.
+ */

Hello Ming,

This is comment explains what blk_mq_stop_hw_queue() should not be used for
and may leave the reader wondering what it is useful for. How about mention=
ing
first that this function is useful to pause .queue_rq() calls as long as th=
e
block driver it will have to return BUSY if .queue_rq() is called?

Bart.=