[PATCH v2 1/4] block/mq-deadline: Rename dd_rq_ioclass() and change its return type

[Bart Van Assche <bvanassche@acm.org>]

All dd_rq_ioclass() callers convert the return value into type enum
dd_prio. Move this conversion into dd_rq_ioclass() and rename this
function. Move the definition of this function. Introduce an additional
caller. No functionality is changed by this patch.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 block/mq-deadline.c | 35 ++++++++++++++---------------------
 1 file changed, 14 insertions(+), 21 deletions(-)

diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index f958e79277b8..8e5f71775cf1 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -119,15 +119,6 @@ deadline_rb_root(struct dd_per_prio *per_prio, struct request *rq)
 	return &per_prio->sort_list[rq_data_dir(rq)];
 }
 
-/*
- * Returns the I/O priority class (IOPRIO_CLASS_*) that has been assigned to a
- * request.
- */
-static u8 dd_rq_ioclass(struct request *rq)
-{
-	return IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
-}
-
 /*
  * get the request before `rq' in sector-sorted order
  */
@@ -190,6 +181,15 @@ static inline struct request *deadline_from_pos(struct dd_per_prio *per_prio,
 	return res;
 }
 
+/*
+ * Returns the I/O priority class (IOPRIO_CLASS_*) that has been assigned to a
+ * request.
+ */
+static enum dd_prio dd_rq_ioprio(struct request *rq)
+{
+	return ioprio_class_to_prio[IOPRIO_PRIO_CLASS(req_get_ioprio(rq))];
+}
+
 static void
 deadline_add_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
 {
@@ -228,8 +228,7 @@ static void dd_request_merged(struct request_queue *q, struct request *req,
 			      enum elv_merge type)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
-	const u8 ioprio_class = dd_rq_ioclass(req);
-	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+	const enum dd_prio prio = dd_rq_ioprio(req);
 	struct dd_per_prio *per_prio = &dd->per_prio[prio];
 
 	/*
@@ -248,8 +247,7 @@ static void dd_merged_requests(struct request_queue *q, struct request *req,
 			       struct request *next)
 {
 	struct deadline_data *dd = q->elevator->elevator_data;
-	const u8 ioprio_class = dd_rq_ioclass(next);
-	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+	const enum dd_prio prio = dd_rq_ioprio(next);
 
 	lockdep_assert_held(&dd->lock);
 
@@ -447,7 +445,6 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd,
 	struct request *rq, *next_rq;
 	enum dd_data_dir data_dir;
 	enum dd_prio prio;
-	u8 ioprio_class;
 
 	lockdep_assert_held(&dd->lock);
 
@@ -545,8 +542,7 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd,
 	dd->batching++;
 	deadline_move_request(dd, per_prio, rq);
 done:
-	ioprio_class = dd_rq_ioclass(rq);
-	prio = ioprio_class_to_prio[ioprio_class];
+	prio = dd_rq_ioprio(rq);
 	dd->per_prio[prio].latest_pos[data_dir] = blk_rq_pos(rq);
 	dd->per_prio[prio].stats.dispatched++;
 	/*
@@ -798,8 +794,6 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 	struct request_queue *q = hctx->queue;
 	struct deadline_data *dd = q->elevator->elevator_data;
 	const enum dd_data_dir data_dir = rq_data_dir(rq);
-	u16 ioprio = req_get_ioprio(rq);
-	u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio);
 	struct dd_per_prio *per_prio;
 	enum dd_prio prio;
 
@@ -811,7 +805,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 	 */
 	blk_req_zone_write_unlock(rq);
 
-	prio = ioprio_class_to_prio[ioprio_class];
+	prio = dd_rq_ioprio(rq);
 	per_prio = &dd->per_prio[prio];
 	if (!rq->elv.priv[0]) {
 		per_prio->stats.inserted++;
@@ -920,8 +914,7 @@ static void dd_finish_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 	struct deadline_data *dd = q->elevator->elevator_data;
-	const u8 ioprio_class = dd_rq_ioclass(rq);
-	const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
+	const enum dd_prio prio = dd_rq_ioprio(rq);
 	struct dd_per_prio *per_prio = &dd->per_prio[prio];
 
 	/*