1 files changed, 17 insertions, 2 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index eb7af39350c6..7b4705b51d4a 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -877,23 +877,31 @@ static void cgroup_clear_directory(struct dentry *dentry)
 
         BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
         spin_lock(&dcache_lock);
+        spin_lock(&dentry->d_lock);
         node = dentry->d_subdirs.next;
         while (node != &dentry->d_subdirs) {
                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
+
+                spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
                 list_del_init(node);
                 if (d->d_inode) {
                         /* This should never be called on a cgroup
                          * directory with child cgroups */
                         BUG_ON(d->d_inode->i_mode & S_IFDIR);
-                        d = dget_locked(d);
+                        dget_locked_dlock(d);
+                        spin_unlock(&d->d_lock);
+                        spin_unlock(&dentry->d_lock);
                         spin_unlock(&dcache_lock);
                         d_delete(d);
                         simple_unlink(dentry->d_inode, d);
                         dput(d);
                         spin_lock(&dcache_lock);
-                }
+                        spin_lock(&dentry->d_lock);
+                } else
+                        spin_unlock(&d->d_lock);
                 node = dentry->d_subdirs.next;
         }
+        spin_unlock(&dentry->d_lock);
         spin_unlock(&dcache_lock);
 }
 
@@ -902,10 +910,17 @@ static void cgroup_clear_directory(struct dentry *dentry)
  */
 static void cgroup_d_remove_dir(struct dentry *dentry)
 {
+        struct dentry *parent;
+
         cgroup_clear_directory(dentry);
 
         spin_lock(&dcache_lock);
+        parent = dentry->d_parent;
+        spin_lock(&parent->d_lock);
+        spin_lock(&dentry->d_lock);
         list_del_init(&dentry->d_u.d_child);
+        spin_unlock(&dentry->d_lock);
+        spin_unlock(&parent->d_lock);
         spin_unlock(&dcache_lock);
         remove_dir(dentry);
 }