Merge branch 'linus' into x86/quirks

1 files changed, 14 insertions, 7 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 358e77564e6..fe00b3b983a 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2039,10 +2039,13 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
 	struct cgroup *cgrp;
 	struct cgroup_iter it;
 	struct task_struct *tsk;
+
 	/*
-	 * Validate dentry by checking the superblock operations
+	 * Validate dentry by checking the superblock operations,
+	 * and make sure it's a directory.
 	 */
-	if (dentry->d_sb->s_op != &cgroup_ops)
+	if (dentry->d_sb->s_op != &cgroup_ops ||
+	    !S_ISDIR(dentry->d_inode->i_mode))
 		 goto err;
 
 	ret = 0;
@@ -2472,10 +2475,7 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
 		mutex_unlock(&cgroup_mutex);
 		return -EBUSY;
 	}
-
-	parent = cgrp->parent;
-	root = cgrp->root;
-	sb = root->sb;
+	mutex_unlock(&cgroup_mutex);
 
 	/*
 	 * Call pre_destroy handlers of subsys. Notify subsystems
@@ -2483,7 +2483,14 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry)
 	 */
 	cgroup_call_pre_destroy(cgrp);
 
-	if (cgroup_has_css_refs(cgrp)) {
+	mutex_lock(&cgroup_mutex);
+	parent = cgrp->parent;
+	root = cgrp->root;
+	sb = root->sb;
+
+	if (atomic_read(&cgrp->count)
+	    || !list_empty(&cgrp->children)
+	    || cgroup_has_css_refs(cgrp)) {
 		mutex_unlock(&cgroup_mutex);
 		return -EBUSY;
 	}