Commit 49fd524f authored Apr 16, 2014 by Jens Axboe

bsg: update check for rq based driver for blk-mq



bsg currently checks ->request_fn to check whether a queue can
handle struct request. But with blk-mq, we don't have a request_fn
yet are request based. Add a queue_is_rq_based() helper and use
that in bsg, I'm guessing this is not the last place we need to
update for this. Besides, it better explains what is being
checked.

Signed-off-by: Jens Axboe <axboe@fb.com>

parent fb1be433

block/bsg.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1008,7 +1008,7 @@ int bsg_register_queue(struct request_queue q, struct device parent,
		/*
		* we need a proper transport to send commands, not a stacked device
		*/
		if (!q->request_fn)
		if (!queue_is_rq_based(q))
		return 0;

		bcd = &q->bsg_dev;

include/linux/blkdev.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -612,6 +612,15 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)

		#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)

		/*
		* Driver can handle struct request, if it either has an old style
		* request_fn defined, or is blk-mq based.
		*/
		static inline bool queue_is_rq_based(struct request_queue *q)
		{
		return q->request_fn \|\| q->mq_ops;
		}

		static inline unsigned int blk_queue_cluster(struct request_queue *q)
		{
		return q->limits.cluster;