blk-mq: move blk_mq_get_driver_tag into blk-mq.c

blk_mq_get_driver_tag() is only used by blk-mq.c and is supposed to
stay in blk-mq.c, so move it and preparing for cleanup code of
get/put driver tag.

Meantime hctx_may_queue() is moved to header file and it is fine
since it is defined as inline always.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-tag.c

@@ -56,37 +56,6 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 	blk_mq_tag_wakeup_all(tags, false);
 }
 
-/*
- * For shared tag users, we track the number of currently active users
- * and attempt to provide a fair share of the tag depth for each of them.
- */
-static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
-				  struct sbitmap_queue *bt)
-{
-	unsigned int depth, users;
-
-	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED))
-		return true;
-	if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
-		return true;
-
-	/*
-	 * Don't try dividing an ant
-	 */
-	if (bt->sb.depth == 1)
-		return true;
-
-	users = atomic_read(&hctx->tags->active_queues);
-	if (!users)
-		return true;
-
-	/*
-	 * Allow at least some tags
-	 */
-	depth = max((bt->sb.depth + users - 1) / users, 4U);
-	return atomic_read(&hctx->nr_active) < depth;
-}
-
 static int __blk_mq_get_tag(struct blk_mq_alloc_data *data,
 			    struct sbitmap_queue *bt)
 {
@@ -191,33 +160,6 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
 	return tag + tag_offset;
 }
 
-bool __blk_mq_get_driver_tag(struct request *rq)
-{
-	struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
-	unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
-	bool shared = blk_mq_tag_busy(rq->mq_hctx);
-	int tag;
-
-	if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
-		bt = &rq->mq_hctx->tags->breserved_tags;
-		tag_offset = 0;
-	}
-
-	if (!hctx_may_queue(rq->mq_hctx, bt))
-		return false;
-	tag = __sbitmap_queue_get(bt);
-	if (tag == BLK_MQ_NO_TAG)
-		return false;
-
-	rq->tag = tag + tag_offset;
-	if (shared) {
-		rq->rq_flags |= RQF_MQ_INFLIGHT;
-		atomic_inc(&rq->mq_hctx->nr_active);
-	}
-	rq->mq_hctx->tags->rqs[rq->tag] = rq;
-	return true;
-}
-
 void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
 		    unsigned int tag)
 {

block/blk-mq-tag.h

@@ -51,14 +51,6 @@ enum {
 	BLK_MQ_TAG_MAX		= BLK_MQ_NO_TAG - 1,
 };
 
-bool __blk_mq_get_driver_tag(struct request *rq);
-static inline bool blk_mq_get_driver_tag(struct request *rq)
-{
-	if (rq->tag != BLK_MQ_NO_TAG)
-		return true;
-	return __blk_mq_get_driver_tag(rq);
-}
-
 extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
 extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
 
@@ -78,6 +70,37 @@ static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
 	__blk_mq_tag_idle(hctx);
 }
 
+/*
+ * For shared tag users, we track the number of currently active users
+ * and attempt to provide a fair share of the tag depth for each of them.
+ */
+static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
+				  struct sbitmap_queue *bt)
+{
+	unsigned int depth, users;
+
+	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED))
+		return true;
+	if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+		return true;
+
+	/*
+	 * Don't try dividing an ant
+	 */
+	if (bt->sb.depth == 1)
+		return true;
+
+	users = atomic_read(&hctx->tags->active_queues);
+	if (!users)
+		return true;
+
+	/*
+	 * Allow at least some tags
+	 */
+	depth = max((bt->sb.depth + users - 1) / users, 4U);
+	return atomic_read(&hctx->nr_active) < depth;
+}
+
 /*
  * This helper should only be used for flush request to share tag
  * with the request cloned from, and both the two requests can't be

block/blk-mq.c

@@ -1103,6 +1103,40 @@ static inline unsigned int queued_to_index(unsigned int queued)
 	return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
 }
 
+static bool __blk_mq_get_driver_tag(struct request *rq)
+{
+	struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
+	unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
+	bool shared = blk_mq_tag_busy(rq->mq_hctx);
+	int tag;
+
+	if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
+		bt = &rq->mq_hctx->tags->breserved_tags;
+		tag_offset = 0;
+	}
+
+	if (!hctx_may_queue(rq->mq_hctx, bt))
+		return false;
+	tag = __sbitmap_queue_get(bt);
+	if (tag == BLK_MQ_NO_TAG)
+		return false;
+
+	rq->tag = tag + tag_offset;
+	if (shared) {
+		rq->rq_flags |= RQF_MQ_INFLIGHT;
+		atomic_inc(&rq->mq_hctx->nr_active);
+	}
+	rq->mq_hctx->tags->rqs[rq->tag] = rq;
+	return true;
+}
+
+static bool blk_mq_get_driver_tag(struct request *rq)
+{
+	if (rq->tag != BLK_MQ_NO_TAG)
+		return true;
+	return __blk_mq_get_driver_tag(rq);
+}
+
 static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
 				int flags, void *key)
 {