Prepare for introducing a second caller of __blk_mq_tagset_iter(). No
functionality has been changed.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 block/blk-mq-tag.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 8a61c481015e..f169beeded64 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -419,6 +419,24 @@ void blk_mq_all_tag_iter(struct blk_mq_tags *tags, blk_mq_rq_iter_fn *fn,
 	__blk_mq_all_tag_iter(tags, fn, priv, BT_TAG_ITER_STATIC_RQS);
 }
 
+static void __blk_mq_tagset_iter(struct blk_mq_tag_set *tagset,
+			blk_mq_rq_iter_fn *fn, void *priv, unsigned long flags)
+{
+	int i, nr_tags, srcu_idx;
+
+	srcu_idx = srcu_read_lock(&tagset->tags_srcu);
+
+	nr_tags = blk_mq_is_shared_tags(tagset->flags) ? 1 :
+		tagset->nr_hw_queues;
+
+	for (i = 0; i < nr_tags; i++) {
+		if (tagset->tags && tagset->tags[i])
+			__blk_mq_all_tag_iter(tagset->tags[i], fn, priv,
+					      flags);
+	}
+	srcu_read_unlock(&tagset->tags_srcu, srcu_idx);
+}
+
 /**
  * blk_mq_tagset_busy_iter - iterate over all started requests in a tag set
  * @tagset:	Tag set to iterate over.
@@ -434,19 +452,7 @@ void blk_mq_all_tag_iter(struct blk_mq_tags *tags, blk_mq_rq_iter_fn *fn,
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 		blk_mq_rq_iter_fn *fn, void *priv)
 {
-	unsigned int flags = tagset->flags;
-	int i, nr_tags, srcu_idx;
-
-	srcu_idx = srcu_read_lock(&tagset->tags_srcu);
-
-	nr_tags = blk_mq_is_shared_tags(flags) ? 1 : tagset->nr_hw_queues;
-
-	for (i = 0; i < nr_tags; i++) {
-		if (tagset->tags && tagset->tags[i])
-			__blk_mq_all_tag_iter(tagset->tags[i], fn, priv,
-					      BT_TAG_ITER_STARTED);
-	}
-	srcu_read_unlock(&tagset->tags_srcu, srcu_idx);
+	__blk_mq_tagset_iter(tagset, fn, priv, BT_TAG_ITER_STARTED);
 }
 EXPORT_SYMBOL(blk_mq_tagset_busy_iter);