From 3d2936f457a847d9d88a9cc127e0eb7a0ebba0ff Mon Sep 17 00:00:00 2001
From: Ming Lei <tom.leiming@gmail.com>
Date: Tue, 27 May 2014 23:35:14 +0800
Subject: [PATCH] block: only allocate/free mq_usage_counter in blk-mq

The percpu counter is only used for blk-mq, so move
its allocation and free inside blk-mq, and don't
allocate it for legacy queue device.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
 block/blk-core.c  | 7 +------
 block/blk-mq.c    | 5 +++++
 block/blk-sysfs.c | 2 --
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 5b6f768a7c01a..29d5fbafd94a7 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -576,12 +576,9 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 	if (!q)
 		return NULL;
 
-	if (percpu_counter_init(&q->mq_usage_counter, 0))
-		goto fail_q;
-
 	q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask);
 	if (q->id < 0)
-		goto fail_c;
+		goto fail_q;
 
 	q->backing_dev_info.ra_pages =
 			(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
@@ -639,8 +636,6 @@ fail_bdi:
 	bdi_destroy(&q->backing_dev_info);
 fail_id:
 	ida_simple_remove(&blk_queue_ida, q->id);
-fail_c:
-	percpu_counter_destroy(&q->mq_usage_counter);
 fail_q:
 	kmem_cache_free(blk_requestq_cachep, q);
 	return NULL;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 07851753a0490..e8b5f74dc1a17 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1781,6 +1781,9 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 	if (!q)
 		goto err_hctxs;
 
+	if (percpu_counter_init(&q->mq_usage_counter, 0))
+		goto err_map;
+
 	q->mq_map = blk_mq_make_queue_map(set);
 	if (!q->mq_map)
 		goto err_map;
@@ -1867,6 +1870,8 @@ void blk_mq_free_queue(struct request_queue *q)
 	blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
 	blk_mq_free_hw_queues(q, set);
 
+	percpu_counter_destroy(&q->mq_usage_counter);
+
 	free_percpu(q->queue_ctx);
 	kfree(q->queue_hw_ctx);
 	kfree(q->mq_map);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 4d6811ac13fdd..23321fbab2931 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -517,8 +517,6 @@ static void blk_release_queue(struct kobject *kobj)
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
 
-	percpu_counter_destroy(&q->mq_usage_counter);
-
 	if (q->mq_ops)
 		blk_mq_free_queue(q);
 
-- 
2.30.2