rid2rsn
if (rid2rsn(dr->dr_id) == 0) {
ds = devfs_ruleset_bynum(rid2rsn(dr->dr_id));
rsnum = rid2rsn(devfs_rid_input(mkrid(rsnum, 0), dm));
if (rid2rsn(rid) == 0)
ds = devfs_ruleset_bynum(rid2rsn(rid));
rsnum = rid2rsn(dr->dr_id);
dk->dk_rule.dr_id = mkrid(rid2rsn(dk->dk_rule.dr_id), dkrn);