1 files changed, 7 insertions, 9 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 04a97bce2270..102ab48ffa13 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6183,17 +6183,15 @@ static int memcg_write_event_control(struct cgroup_subsys_state *css,
          * automatically removed on cgroup destruction but the removal is
          * asynchronous, so take an extra ref on @css.
          */
-        rcu_read_lock();
-
+        cfile_css = css_tryget_from_dir(cfile.file->f_dentry->d_parent,
+                                        &memory_cgrp_subsys);
         ret = -EINVAL;
-        cfile_css = css_from_dir(cfile.file->f_dentry->d_parent,
-                                 &memory_cgrp_subsys);
-        if (cfile_css == css && css_tryget(css))
-                ret = 0;
-
-        rcu_read_unlock();
-        if (ret)
+        if (IS_ERR(cfile_css))
                 goto out_put_cfile;
+        if (cfile_css != css) {
+                css_put(cfile_css);
+                goto out_put_cfile;
+        }
 
         ret = event->register_event(memcg, event->eventfd, buffer);
         if (ret)