v4.19.13 snapshot.
diff --git a/include/linux/dnotify.h b/include/linux/dnotify.h
new file mode 100644
index 0000000..0aad774
--- /dev/null
+++ b/include/linux/dnotify.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_DNOTIFY_H
+#define _LINUX_DNOTIFY_H
+/*
+ * Directory notification for Linux
+ *
+ * Copyright (C) 2000,2002 Stephen Rothwell
+ */
+
+#include <linux/fs.h>
+
+struct dnotify_struct {
+ struct dnotify_struct * dn_next;
+ __u32 dn_mask;
+ int dn_fd;
+ struct file * dn_filp;
+ fl_owner_t dn_owner;
+};
+
+#ifdef __KERNEL__
+
+
+#ifdef CONFIG_DNOTIFY
+
+#define DNOTIFY_ALL_EVENTS (FS_DELETE | FS_DELETE_CHILD |\
+ FS_MODIFY | FS_MODIFY_CHILD |\
+ FS_ACCESS | FS_ACCESS_CHILD |\
+ FS_ATTRIB | FS_ATTRIB_CHILD |\
+ FS_CREATE | FS_DN_RENAME |\
+ FS_MOVED_FROM | FS_MOVED_TO)
+
+extern int dir_notify_enable;
+extern void dnotify_flush(struct file *, fl_owner_t);
+extern int fcntl_dirnotify(int, struct file *, unsigned long);
+
+#else
+
+static inline void dnotify_flush(struct file *filp, fl_owner_t id)
+{
+}
+
+static inline int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
+{
+ return -EINVAL;
+}
+
+#endif /* CONFIG_DNOTIFY */
+
+#endif /* __KERNEL __ */
+
+#endif /* _LINUX_DNOTIFY_H */