blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}()

Refactor blk_mq_free_map_and_requests() such that it can be used at many
sites at which the tag map and rqs are freed.

Also rename to blk_mq_free_map_and_rqs(), which is shorter and matches the
alloc equivalent.

Suggested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/1633429419-228500-12-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-tag.c

@@ -607,8 +607,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 		if (!new)
 			return -ENOMEM;
 
-		blk_mq_free_rqs(set, *tagsptr, hctx->queue_num);
-		blk_mq_free_rq_map(*tagsptr, set->flags);
+		blk_mq_free_map_and_rqs(set, *tagsptr, hctx->queue_num);
 		*tagsptr = new;
 	} else {
 		/*

block/blk-mq.c

@@ -2887,15 +2887,15 @@ static bool __blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
 	return set->tags[hctx_idx];
 }
 
-static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
-					 unsigned int hctx_idx)
+void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
+			     struct blk_mq_tags *tags,
+			     unsigned int hctx_idx)
 {
 	unsigned int flags = set->flags;
 
-	if (set->tags && set->tags[hctx_idx]) {
-		blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx);
-		blk_mq_free_rq_map(set->tags[hctx_idx], flags);
-		set->tags[hctx_idx] = NULL;
+	if (tags) {
+		blk_mq_free_rqs(set, tags, hctx_idx);
+		blk_mq_free_rq_map(tags, flags);
 	}
 }
 
@@ -2976,8 +2976,10 @@ static void blk_mq_map_swqueue(struct request_queue *q)
 			 * fallback in case of a new remap fails
 			 * allocation
 			 */
-			if (i && set->tags[i])
-				blk_mq_free_map_and_requests(set, i);
+			if (i && set->tags[i]) {
+				blk_mq_free_map_and_rqs(set, set->tags[i], i);
+				set->tags[i] = NULL;
+			}
 
 			hctx->tags = NULL;
 			continue;
@@ -3273,8 +3275,8 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
 		struct blk_mq_hw_ctx *hctx = hctxs[j];
 
 		if (hctx) {
-			if (hctx->tags)
-				blk_mq_free_map_and_requests(set, j);
+			blk_mq_free_map_and_rqs(set, set->tags[j], j);
+			set->tags[j] = NULL;
 			blk_mq_exit_hctx(q, set, hctx, j);
 			hctxs[j] = NULL;
 		}
@@ -3370,8 +3372,10 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
 	return 0;
 
 out_unwind:
-	while (--i >= 0)
-		blk_mq_free_map_and_requests(set, i);
+	while (--i >= 0) {
+		blk_mq_free_map_and_rqs(set, set->tags[i], i);
+		set->tags[i] = NULL;
+	}
 
 	return -ENOMEM;
 }
@@ -3566,8 +3570,10 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
 	return 0;
 
 out_free_mq_rq_maps:
-	for (i = 0; i < set->nr_hw_queues; i++)
-		blk_mq_free_map_and_requests(set, i);
+	for (i = 0; i < set->nr_hw_queues; i++) {
+		blk_mq_free_map_and_rqs(set, set->tags[i], i);
+		set->tags[i] = NULL;
+	}
 out_free_mq_map:
 	for (i = 0; i < set->nr_maps; i++) {
 		kfree(set->map[i].mq_map);
@@ -3599,8 +3605,10 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
 {
 	int i, j;
 
-	for (i = 0; i < set->nr_hw_queues; i++)
-		blk_mq_free_map_and_requests(set, i);
+	for (i = 0; i < set->nr_hw_queues; i++) {
+		blk_mq_free_map_and_rqs(set, set->tags[i], i);
+		set->tags[i] = NULL;
+	}
 
 	if (blk_mq_is_sbitmap_shared(set->flags))
 		blk_mq_exit_shared_sbitmap(set);

block/blk-mq.h

@@ -57,7 +57,9 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);
 struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
 				unsigned int hctx_idx, unsigned int depth);
-
+void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
+			     struct blk_mq_tags *tags,
+			     unsigned int hctx_idx);
 /*
  * Internal helpers for request insertion into sw queues
  */