diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 30b93b2..eebb617 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -186,6 +186,8 @@
 
 #define DCACHE_FSNOTIFY_PARENT_WATCHED	0x0080 /* Parent inode is watched by some fsnotify listener */
 
+#define DCACHE_CANT_MOUNT	0x0100
+
 extern spinlock_t dcache_lock;
 extern seqlock_t rename_lock;
 
@@ -358,6 +360,18 @@
 	return d_unhashed(dentry) && !IS_ROOT(dentry);
 }
 
+static inline int cant_mount(struct dentry *dentry)
+{
+	return (dentry->d_flags & DCACHE_CANT_MOUNT);
+}
+
+static inline void dont_mount(struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags |= DCACHE_CANT_MOUNT;
+	spin_unlock(&dentry->d_lock);
+}
+
 static inline struct dentry *dget_parent(struct dentry *dentry)
 {
 	struct dentry *ret;