block: add queue_is_mq() helper

Various spots check for q->mq_ops being non-NULL, but provide
a helper to do this instead.

Where the ->mq_ops != NULL check is redundant, remove it.

Since mq == rq-based now that legacy is gone, get rid of the
queue_is_rq_based() and just use queue_is_mq() everywhere.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 1 insertions, 5 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1d185f1fc333..41aaa05e42c1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -656,11 +656,7 @@ static inline bool blk_account_rq(struct request *rq)
 
 #define rq_data_dir(rq)         (op_is_write(req_op(rq)) ? WRITE : READ)
 
-/*
- * 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)
+static inline bool queue_is_mq(struct request_queue *q)
 {
         return q->mq_ops;
 }