diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4b86f80..49d8eb7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -886,6 +886,12 @@
 #define FL_SLEEP	128	/* A blocking lock */
 
 /*
+ * Special return value from posix_lock_file() and vfs_lock_file() for
+ * asynchronous locking.
+ */
+#define FILE_LOCK_DEFERRED 1
+
+/*
  * The POSIX file lock owner is determined by
  * the "struct files_struct" in the thread group
  * (or NULL for no owner - BSD locks).