block: remove __elevator_change

[Christoph Hellwig <hch@xxxxxx>]

Not much of a point in sharing code between callers with very different
expectations.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 block/elevator.c | 45 ++++++++++++++++++++-------------------------
 1 file changed, 20 insertions(+), 25 deletions(-)

diff --git a/block/elevator.c b/block/elevator.c
index 59ff0abde920..b358858387a0 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -674,25 +674,13 @@ static int elevator_change_done(struct request_queue *q,
 	return ret;
 }
 
-/*
- * Switch this queue to the given IO scheduler.
- */
-static int __elevator_change(struct request_queue *q,
-			     struct elv_change_ctx *ctx)
-{
-	lockdep_assert_held(&q->tag_set->update_nr_hwq_sema);
-
-	/* Make sure queue is not in the middle of being removed */
-	if (!ctx->init && !blk_queue_registered(q))
-		return -ENOENT;
-	return elevator_switch(q, ctx);
-}
-
 static int elevator_change(struct request_queue *q,
 			   struct elv_change_ctx *ctx)
 {
 	unsigned int memflags;
-	int ret = 0;
+	int ret;
+
+	lockdep_assert_held(&q->tag_set->update_nr_hwq_sema);
 
 	memflags = blk_mq_freeze_queue(q);
 	/*
@@ -706,14 +694,20 @@ static int elevator_change(struct request_queue *q,
 	 */
 	blk_mq_cancel_work_sync(q);
 	mutex_lock(&q->elevator_lock);
-	if (!q->elevator || !elevator_match(q->elevator->type, ctx->name))
-		ret = __elevator_change(q, ctx);
+	/* Make sure queue is not in the middle of being removed */
+	ret = -ENOENT;
+	if (!ctx->init && !blk_queue_registered(q))
+		goto out_unlock;
+	ret = 0;
+	if (q->elevator && elevator_match(q->elevator->type, ctx->name))
+		goto out_unlock;
+	ret = elevator_switch(q, ctx);
+out_unlock:
 	mutex_unlock(&q->elevator_lock);
 	blk_mq_unfreeze_queue(q, memflags);
-	if (!ret)
-		ret = elevator_change_done(q, ctx);
-
-	return ret;
+	if (ret)
+		return ret;
+	return elevator_change_done(q, ctx);
 }
 
 /*
@@ -768,17 +762,18 @@ void elevator_set_none(struct request_queue *q)
 void elv_update_nr_hw_queues(struct request_queue *q)
 {
 	struct elv_change_ctx ctx = {
-		.name	= "none",
 		.uevent	= true,
 	};
-	int ret = -ENODEV;
+	int ret = -ENOENT;
 
+	lockdep_assert_held(&q->tag_set->update_nr_hwq_sema);
 	WARN_ON_ONCE(q->mq_freeze_depth == 0);
 
 	mutex_lock(&q->elevator_lock);
-	if (q->elevator && !blk_queue_dying(q))
+	if (blk_queue_registered(q) && !blk_queue_dying(q) && q->elevator) {
 		ctx.name = q->elevator->type->elevator_name;
-	ret = __elevator_change(q, &ctx);
+		ret = elevator_switch(q, &ctx);
+	}
 	mutex_unlock(&q->elevator_lock);
 	blk_mq_unfreeze_queue_nomemrestore(q);
 
-- 
2.47.2


--liOOAslEiF7prFVr--