fanotify: clear all fanotify marks

fanotify listeners may want to clear all marks.  They may want to do this
to destroy all of their inode marks which have nothing but ignores.
Realistically this is useful for av vendors who update policy and want to
clear all of their cached allows.

Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index e43934d..385896c 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -32,6 +32,7 @@
 #define FAN_MARK_MOUNT		0x00000010
 #define FAN_MARK_IGNORED_MASK	0x00000020
 #define FAN_MARK_IGNORED_SURV_MODIFY	0x00000040
+#define FAN_MARK_FLUSH		0x00000080
 
 #define FAN_ALL_MARK_FLAGS	(FAN_MARK_ADD |\
 				 FAN_MARK_REMOVE |\