checkalias
if ((nvp = checkalias(vp, ip->inode.iso_rdev, mp)) != NULL) {
if ((nvp = checkalias(vp, up->u_dev, ump->um_mountp)) != NULL) {
if ((nvp = checkalias(vp, dev, NULL)) != NULL) {
nvp = checkalias(vp, (dev_t)rdev, vp->v_mount);
struct vnode *checkalias(struct vnode *, dev_t, struct mount *);
if ((nvp = checkalias(vp, node->tn_spec.tn_dev.tn_rdev, mp))) {
nvp = checkalias(vp, letoh32(ip->i_e2din->e2di_rdev), mp);
if ((nvp = checkalias(vp, DIP(ip, rdev), mntp)) != NULL) {
if (checkalias(devvp, makedev(255, mfs_minor), NULL))