Commit 5feeacdd authored Apr 20, 2017 by Jens Axboe

blk-mq: add might_sleep check to blk_mq_get_driver_tag()



If the caller passes in wait=true, it has to be able to block
for a driver tag. We just had a bug where flush insertion
would block on tag allocation, while we had preempt disabled.
Ensure that we catch cases like that earlier next time.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 0206319f

block/blk-mq.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -864,6 +864,8 @@ bool blk_mq_get_driver_tag(struct request rq, struct blk_mq_hw_ctx *hctx,
		.flags = wait ? 0 : BLK_MQ_REQ_NOWAIT,
		};

		might_sleep_if(wait);

		if (rq->tag != -1)
		goto done;