cgroup: remove unnecessary 0 check from css_from_id()

css_idr allocation starts at 1, so index 0 will never point to an
item. css_from_id() currently filters that before asking idr_find(),
but idr_find() would also just return NULL, so this is not needed.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 36fc0ff..78f6d18 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -6162,7 +6162,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
 struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss)
 {
        WARN_ON_ONCE(!rcu_read_lock_held());
-       return id > 0 ? idr_find(&ss->css_idr, id) : NULL;
+       return idr_find(&ss->css_idr, id);
 }
 
 /**