cfq: Remove useless css reference get

There's no need to take css reference here, for the caller
has already called rcu_read_lock() to prevent cgroup from
being removed.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 0 insertions, 5 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index e3dedfd3bcb4..10eb286f1f49 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -951,10 +951,6 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
         struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info;
         unsigned int major, minor;
 
-        /* Do we need to take this reference */
-        if (!blkiocg_css_tryget(blkcg))
-                return NULL;;
-
         cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
         if (cfqg || !create)
                 goto done;
@@ -985,7 +981,6 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
         hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
 
 done:
-        blkiocg_css_put(blkcg);
         return cfqg;
 }