block: Rename BLKDEV_MAX_RQ -> BLKDEV_DEFAULT_RQ

It is a bit confusing that there is BLKDEV_MAX_RQ and MAX_SCHED_RQ, as
the name BLKDEV_MAX_RQ would imply the max requests always, which it is
not.

Rename to BLKDEV_MAX_RQ to BLKDEV_DEFAULT_RQ, matching its usage - that being
the default number of requests assigned when allocating a request queue.
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/1633429419-228500-3-git-send-email-john.garry@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -587,7 +587,7 @@ struct request_queue *blk_alloc_queue(int node_id)
 
 	blk_queue_dma_alignment(q, 511);
 	blk_set_default_limits(&q->limits);
-	q->nr_requests = BLKDEV_MAX_RQ;
+	q->nr_requests = BLKDEV_DEFAULT_RQ;
 
 	return q;
 

block/blk-mq-sched.c

@@ -606,7 +606,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 	 * Additionally, this is a per-hw queue depth.
 	 */
 	q->nr_requests = 2 * min_t(unsigned int, q->tag_set->queue_depth,
-				   BLKDEV_MAX_RQ);
+				   BLKDEV_DEFAULT_RQ);
 
 	queue_for_each_hw_ctx(q, hctx, i) {
 		ret = blk_mq_sched_alloc_tags(q, hctx, i);

block/blk-mq-sched.h

@@ -6,7 +6,7 @@
 #include "blk-mq.h"
 #include "blk-mq-tag.h"
 
-#define MAX_SCHED_RQ (16 * BLKDEV_MAX_RQ)
+#define MAX_SCHED_RQ (16 * BLKDEV_DEFAULT_RQ)
 
 void blk_mq_sched_assign_ioc(struct request *rq);
 

drivers/block/rbd.c

@@ -836,7 +836,7 @@ struct rbd_options {
 	u32 alloc_hint_flags;  /* CEPH_OSD_OP_ALLOC_HINT_FLAG_* */
 };
 
-#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_MAX_RQ
+#define RBD_QUEUE_DEPTH_DEFAULT	BLKDEV_DEFAULT_RQ
 #define RBD_ALLOC_SIZE_DEFAULT	(64 * 1024)
 #define RBD_LOCK_TIMEOUT_DEFAULT 0  /* no timeout */
 #define RBD_READ_ONLY_DEFAULT	false

include/linux/blk-mq.h

@@ -12,7 +12,7 @@ struct blk_mq_tags;
 struct blk_flush_queue;
 
 #define BLKDEV_MIN_RQ	4
-#define BLKDEV_MAX_RQ	128	/* Default maximum */
+#define BLKDEV_DEFAULT_RQ	128
 
 typedef void (rq_end_io_fn)(struct request *, blk_status_t);