getdmapnam
if ((dm_new = getdmapnam(da->da_devname)) == NULL) {
if ((dm = getdmapnam(da->da_devname)) == NULL) {
if ((dm = getdmapnam(da->da_devname)) == NULL) {
if (getdmapnam(dmap.dmap_devname) != NULL) {
if ((dmapp = getdmapnam(*argv)) != NULL) {
devmap_t *getdmapnam(char *);