1 files changed, 19 insertions, 10 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 027b66e66698..c389f4258681 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4041,14 +4041,18 @@ static void init_cgroup_css(struct cgroup_subsys_state *css,
         INIT_WORK(&css->dput_work, css_dput_fn);
 }
 
-/* invoke ->post_create() on a new CSS and mark it online */
-static void online_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
+/* invoke ->post_create() on a new CSS and mark it online if successful */
+static int online_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
 {
+        int ret = 0;
+
         lockdep_assert_held(&cgroup_mutex);
 
         if (ss->post_create)
-                ss->post_create(cgrp);
-        cgrp->subsys[ss->subsys_id]->flags |= CSS_ONLINE;
+                ret = ss->post_create(cgrp);
+        if (!ret)
+                cgrp->subsys[ss->subsys_id]->flags |= CSS_ONLINE;
+        return ret;
 }
 
 /* if the CSS is online, invoke ->pre_destory() on it and mark it offline */
@@ -4174,12 +4178,15 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
         list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children);
         root->number_of_cgroups++;
 
-        for_each_subsys(root, ss) {
-                /* each css holds a ref to the cgroup's dentry */
+        /* each css holds a ref to the cgroup's dentry */
+        for_each_subsys(root, ss)
                 dget(dentry);
 
-                /* creation succeeded, notify subsystems */
-                online_css(ss, cgrp);
+        /* creation succeeded, notify subsystems */
+        for_each_subsys(root, ss) {
+                err = online_css(ss, cgrp);
+                if (err)
+                        goto err_destroy;
         }
 
         err = cgroup_populate_dir(cgrp, true, root->subsys_mask);
@@ -4393,7 +4400,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
         BUG_ON(!list_empty(&init_task.tasks));
 
         ss->active = 1;
-        online_css(ss, dummytop);
+        BUG_ON(online_css(ss, dummytop));
 
         mutex_unlock(&cgroup_mutex);
 
@@ -4500,7 +4507,9 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
         write_unlock(&css_set_lock);
 
         ss->active = 1;
-        online_css(ss, dummytop);
+        ret = online_css(ss, dummytop);
+        if (ret)
+                goto err_unload;
 
         /* success! */
         mutex_unlock(&cgroup_mutex);