diff --git a/include/linux/fs.h b/include/linux/fs.h
index 134b320..43aef9b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -716,6 +716,7 @@
 #define FL_POSIX	1
 #define FL_FLOCK	2
 #define FL_ACCESS	8	/* not trying to lock, just looking */
+#define FL_EXISTS	16	/* when unlocking, test for existence */
 #define FL_LEASE	32	/* lease held on this file */
 #define FL_CLOSE	64	/* unlock on close */
 #define FL_SLEEP	128	/* A blocking lock */