Index: mpath.c
===================================================================
RCS file: /cvs/src/sys/scsi/mpath.c,v
retrieving revision 1.37
diff -u -p -r1.37 mpath.c
--- mpath.c	14 Sep 2014 14:17:26 -0000	1.37
+++ mpath.c	2 Mar 2015 03:29:24 -0000
@@ -427,6 +427,9 @@ mpath_path_probe(struct scsi_link *link)
 	if (link->id == NULL)
 		return (EINVAL);
 
+	if (ISSET(link->flags, SDEV_UMASS))
+		return (EINVAL);
+
 	if (mpath == link->adapter_softc)
 		return (ENXIO);