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/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index 1b61d0a..8f1aa02 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -51,6 +51,11 @@
 	}
 }
 
+void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
+{
+	fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_VFSMOUNT);
+}
+
 /*
  * Recalculate the mask of events relevant to a given vfsmount locked.
  */