fs: Avoid userspace mounting anon_inodefs filesystem

[~andy/linux] / fs / kernfs / dir.c

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 5104cf5d25c5af6d28996bbe9b4a00700bf4479c..bd6e18be6e1a231c10867bc8f4e292e49353d03f 100644 (file)
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -187,19 +187,23 @@ static void kernfs_deactivate(struct kernfs_node *kn)
 
        kn->u.completion = (void *)&wait;
 
-       rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
+       if (kn->flags & KERNFS_LOCKDEP)
+               rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
        /* atomic_add_return() is a mb(), put_active() will always see
         * the updated kn->u.completion.
         */
        v = atomic_add_return(KN_DEACTIVATED_BIAS, &kn->active);
 
        if (v != KN_DEACTIVATED_BIAS) {
-               lock_contended(&kn->dep_map, _RET_IP_);
+               if (kn->flags & KERNFS_LOCKDEP)
+                       lock_contended(&kn->dep_map, _RET_IP_);
                wait_for_completion(&wait);
        }
 
-       lock_acquired(&kn->dep_map, _RET_IP_);
-       rwsem_release(&kn->dep_map, 1, _RET_IP_);
+       if (kn->flags & KERNFS_LOCKDEP) {
+               lock_acquired(&kn->dep_map, _RET_IP_);
+               rwsem_release(&kn->dep_map, 1, _RET_IP_);
+       }
 }
 
 /**