1 files changed, 28 insertions, 2 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 1d5196889048..641e56494a92 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -113,6 +113,19 @@ static inline void css_get(struct cgroup_subsys_state *css)
 }
 
 /**
+ * css_get_many - obtain references on the specified css
+ * @css: target css
+ * @n: number of references to get
+ *
+ * The caller must already have a reference.
+ */
+static inline void css_get_many(struct cgroup_subsys_state *css, unsigned int n)
+{
+        if (!(css->flags & CSS_NO_REF))
+                percpu_ref_get_many(&css->refcnt, n);
+}
+
+/**
  * css_tryget - try to obtain a reference on the specified css
  * @css: target css
  *
@@ -159,6 +172,19 @@ static inline void css_put(struct cgroup_subsys_state *css)
                 percpu_ref_put(&css->refcnt);
 }
 
+/**
+ * css_put_many - put css references
+ * @css: target css
+ * @n: number of references to put
+ *
+ * Put references obtained via css_get() and css_tryget_online().
+ */
+static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n)
+{
+        if (!(css->flags & CSS_NO_REF))
+                percpu_ref_put_many(&css->refcnt, n);
+}
+
 /* bits in struct cgroup flags field */
 enum {
         /* Control Group requires release notifications to userspace */
@@ -367,8 +393,8 @@ struct css_set {
  * struct cftype: handler definitions for cgroup control files
  *
  * When reading/writing to a file:
- *      - the cgroup to use is file->f_dentry->d_parent->d_fsdata
- *      - the 'cftype' of the file is file->f_dentry->d_fsdata
+ *      - the cgroup to use is file->f_path.dentry->d_parent->d_fsdata
+ *      - the 'cftype' of the file is file->f_path.dentry->d_fsdata
  */
 
 /* cftype->flags */