diff --git a/fs/inode.c b/fs/inode.c
index bf6adf122c688b337abf5d7c00288857b74a5927..f97de0aeb3b69dcd320668ccbf6bbeb6e9d57932 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -567,6 +567,18 @@ EXPORT_SYMBOL(new_inode);
 
 void unlock_new_inode(struct inode *inode)
 {
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct file_system_type *type = inode->i_sb->s_type;
+	/*
+	 * ensure nobody is actually holding i_mutex
+	 */
+	mutex_destroy(&inode->i_mutex);
+	mutex_init(&inode->i_mutex);
+	if (inode->i_mode & S_IFDIR)
+		lockdep_set_class(&inode->i_mutex, &type->i_mutex_dir_key);
+	else
+		lockdep_set_class(&inode->i_mutex, &type->i_mutex_key);
+#endif
 	/*
 	 * This is special!  We do not need the spinlock
 	 * when clearing I_LOCK, because we're guaranteed
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0cad20e125852527f4c243b82922966e218fcce5..6d760f1ad87521c932d12d649cc0171d8e14f696 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1308,6 +1308,7 @@ struct file_system_type {
 
 	struct lock_class_key i_lock_key;
 	struct lock_class_key i_mutex_key;
+	struct lock_class_key i_mutex_dir_key;
 	struct lock_class_key i_alloc_sem_key;
 };