2 files changed, 12 insertions, 5 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index d08cfe7e12e5..14160b5b693f 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -76,6 +76,12 @@ enum {
         CSS_REMOVED, /* This CSS is dead */
 };
 
+/* Caller must verify that the css is not for root cgroup */
+static inline void __css_get(struct cgroup_subsys_state *css, int count)
+{
+        atomic_add(count, &css->refcnt);
+}
+
 /*
  * Call css_get() to hold a reference on the css; it can be used
  * for a reference obtained via:
@@ -87,7 +93,7 @@ static inline void css_get(struct cgroup_subsys_state *css)
 {
         /* We don't need to reference count the root state */
         if (!test_bit(CSS_ROOT, &css->flags))
-                atomic_inc(&css->refcnt);
+                __css_get(css, 1);
 }
 
 static inline bool css_is_removed(struct cgroup_subsys_state *css)
@@ -118,11 +124,11 @@ static inline bool css_tryget(struct cgroup_subsys_state *css)
  * css_get() or css_tryget()
  */
 
-extern void __css_put(struct cgroup_subsys_state *css);
+extern void __css_put(struct cgroup_subsys_state *css, int count);
 static inline void css_put(struct cgroup_subsys_state *css)
 {
         if (!test_bit(CSS_ROOT, &css->flags))
-                __css_put(css);
+                __css_put(css, 1);
 }
 
 /* bits in struct cgroup flags field */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index be45d2f6008a..cace83ddbcdc 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3746,12 +3746,13 @@ static void check_for_release(struct cgroup *cgrp)
         }
 }
 
-void __css_put(struct cgroup_subsys_state *css)
+/* Caller must verify that the css is not for root cgroup */
+void __css_put(struct cgroup_subsys_state *css, int count)
 {
         struct cgroup *cgrp = css->cgroup;
         int val;
         rcu_read_lock();
-        val = atomic_dec_return(&css->refcnt);
+        val = atomic_sub_return(count, &css->refcnt);
         if (val == 1) {
                 if (notify_on_release(cgrp)) {
                         set_bit(CGRP_RELEASABLE, &cgrp->flags);