[PATCH RFT 1/3] blk-mq: Drop busy_iter_fn blk_mq_hw_ctx argument

[John Garry]

The only user of blk_mq_hw_ctx blk_mq_hw_ctx argument is
blk_mq_rq_inflight().

Function blk_mq_rq_inflight() uses the hctx to find the associated request
queue to match against the request. However this same check is already
done in caller bt_iter(), so drop this check.

With that change there are no more users of busy_iter_fn blk_mq_hw_ctx
argument, so drop the argument.

Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 block/blk-mq-tag.c     |  2 +-
 block/blk-mq.c         | 17 ++++++++---------
 include/linux/blk-mq.h |  3 +--
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 995336abee33..0d773c44a7ec 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -254,7 +254,7 @@ static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data)
 		return true;
 
 	if (rq->q == hctx->queue && rq->mq_hctx == hctx)
-		ret = iter_data->fn(hctx, rq, iter_data->data, reserved);
+		ret = iter_data->fn(rq, iter_data->data, reserved);
 	blk_mq_put_rq_ref(rq);
 	return ret;
 }
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 07eb1412760b..c26e6c9301dd 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -126,8 +126,7 @@ struct mq_inflight {
 	unsigned int inflight[2];
 };
 
-static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
-				  struct request *rq, void *priv,
+static bool blk_mq_check_inflight(struct request *rq, void *priv,
 				  bool reserved)
 {
 	struct mq_inflight *mi = priv;
@@ -1136,14 +1135,15 @@ void blk_mq_delay_kick_requeue_list(struct request_queue *q,
 }
 EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
 
-static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq,
-			       void *priv, bool reserved)
+static bool blk_mq_rq_inflight(struct request *rq, void *priv,
+			       bool reserved)
 {
 	/*
-	 * If we find a request that isn't idle and the queue matches,
-	 * we know the queue is busy. Return false to stop the iteration.
+	 * If we find a request that isn't idle we know the queue is busy
+	 * as it's checked in the iter.
+	 * Return false to stop the iteration.
 	 */
-	if (blk_mq_request_started(rq) && rq->q == hctx->queue) {
+	if (blk_mq_request_started(rq)) {
 		bool *busy = priv;
 
 		*busy = true;
@@ -1205,8 +1205,7 @@ void blk_mq_put_rq_ref(struct request *rq)
 		__blk_mq_free_request(rq);
 }
 
-static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
-		struct request *rq, void *priv, bool reserved)
+static bool blk_mq_check_expired(struct request *rq, void *priv, bool reserved)
 {
 	unsigned long *next = priv;
 
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 8682663e7368..da8de0d6f99b 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -479,8 +479,7 @@ struct blk_mq_queue_data {
 	bool last;
 };
 
-typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
-		bool);
+typedef bool (busy_iter_fn)(struct request *, void *, bool);
 typedef bool (busy_tag_iter_fn)(struct request *, void *, bool);
 
 /**
-- 
2.17.1