blk-mq: Some tag allocation code refactoring

The tag allocation code to alloc the sbitmap pairs is common for regular
bitmaps tags and shared sbitmap, so refactor into a common function.

Also remove superfluous "flags" argument from blk_mq_init_shared_sbitmap().

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1620907258-30910-2-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-tag.c

@@ -471,39 +471,54 @@ static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth,
 				       node);
 }
 
-static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
-				   int node, int alloc_policy)
+int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
+			struct sbitmap_queue *breserved_tags,
+			unsigned int queue_depth, unsigned int reserved,
+			int node, int alloc_policy)
 {
-	unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
+	unsigned int depth = queue_depth - reserved;
 	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
 
-	if (bt_alloc(&tags->__bitmap_tags, depth, round_robin, node))
+	if (bt_alloc(bitmap_tags, depth, round_robin, node))
 		return -ENOMEM;
-	if (bt_alloc(&tags->__breserved_tags, tags->nr_reserved_tags,
-		     round_robin, node))
+	if (bt_alloc(breserved_tags, reserved, round_robin, node))
 		goto free_bitmap_tags;
 
+	return 0;
+
+free_bitmap_tags:
+	sbitmap_queue_free(bitmap_tags);
+	return -ENOMEM;
+}
+
+static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
+				   int node, int alloc_policy)
+{
+	int ret;
+
+	ret = blk_mq_init_bitmaps(&tags->__bitmap_tags,
+				  &tags->__breserved_tags,
+				  tags->nr_tags, tags->nr_reserved_tags,
+				  node, alloc_policy);
+	if (ret)
+		return ret;
+
 	tags->bitmap_tags = &tags->__bitmap_tags;
 	tags->breserved_tags = &tags->__breserved_tags;
 
 	return 0;
-free_bitmap_tags:
-	sbitmap_queue_free(&tags->__bitmap_tags);
-	return -ENOMEM;
 }
 
-int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int flags)
+int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set)
 {
-	unsigned int depth = set->queue_depth - set->reserved_tags;
 	int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags);
-	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
-	int i, node = set->numa_node;
+	int i, ret;
 
-	if (bt_alloc(&set->__bitmap_tags, depth, round_robin, node))
-		return -ENOMEM;
-	if (bt_alloc(&set->__breserved_tags, set->reserved_tags,
-		     round_robin, node))
-		goto free_bitmap_tags;
+	ret = blk_mq_init_bitmaps(&set->__bitmap_tags, &set->__breserved_tags,
+				  set->queue_depth, set->reserved_tags,
+				  set->numa_node, alloc_policy);
+	if (ret)
+		return ret;
 
 	for (i = 0; i < set->nr_hw_queues; i++) {
 		struct blk_mq_tags *tags = set->tags[i];
@@ -513,9 +528,6 @@ int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int flags)
 	}
 
 	return 0;
-free_bitmap_tags:
-	sbitmap_queue_free(&set->__bitmap_tags);
-	return -ENOMEM;
 }
 
 void blk_mq_exit_shared_sbitmap(struct blk_mq_tag_set *set)

block/blk-mq-tag.h

@@ -32,11 +32,14 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
 					unsigned int reserved_tags,
 					int node, unsigned int flags);
 extern void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags);
+extern int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
+			       struct sbitmap_queue *breserved_tags,
+			       unsigned int queue_depth,
+			       unsigned int reserved,
+			       int node, int alloc_policy);
 
-extern int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set,
-				      unsigned int flags);
+extern int blk_mq_init_shared_sbitmap(struct blk_mq_tag_set *set);
 extern void blk_mq_exit_shared_sbitmap(struct blk_mq_tag_set *set);
-
 extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
 extern void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
 			   unsigned int tag);

block/blk-mq.c

@@ -3564,7 +3564,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
 	if (blk_mq_is_sbitmap_shared(set->flags)) {
 		atomic_set(&set->active_queues_shared_sbitmap, 0);
 
-		if (blk_mq_init_shared_sbitmap(set, set->flags)) {
+		if (blk_mq_init_shared_sbitmap(set)) {
 			ret = -ENOMEM;
 			goto out_free_mq_rq_maps;
 		}