1 files changed, 22 insertions, 0 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 4d67a39c58a8..4e8b16a8266c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -586,6 +586,21 @@ static struct inode *cgroup_new_inode(mode_t mode, struct super_block *sb)
         return inode;
 }
 
+/*
+ * Call subsys's pre_destroy handler.
+ * This is called before css refcnt check.
+ */
+
+static void cgroup_call_pre_destroy(struct cgroup *cgrp)
+{
+        struct cgroup_subsys *ss;
+        for_each_subsys(cgrp->root, ss)
+                if (ss->pre_destroy && cgrp->subsys[ss->subsys_id])
+                        ss->pre_destroy(ss, cgrp);
+        return;
+}
+
+
 static void cgroup_diput(struct dentry *dentry, struct inode *inode)
 {
         /* is dentry a directory ? if so, kfree() associated cgroup */
@@ -2160,6 +2175,13 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
         parent = cgrp->parent;
         root = cgrp->root;
         sb = root->sb;
+        /*
+         * Call pre_destroy handlers of subsys
+         */
+        cgroup_call_pre_destroy(cgrp);
+        /*
+         * Notify subsyses that rmdir() request comes.
+         */
 
         if (cgroup_has_css_refs(cgrp)) {
                 mutex_unlock(&cgroup_mutex);