i_rdev
ip->i_rdev = 0;
addaliasu(vp, umajor(ip->i_rdev), uminor(ip->i_rdev));
ip->i_rdev = makeudev(vap->va_rmajor, vap->va_rminor);
ip->i_rdev = 0;
addaliasu(vp, umajor(ip->i_rdev), uminor(ip->i_rdev));
ip->i_rdev = makeudev(vap->va_rmajor, vap->va_rminor);
vap->va_rmajor = umajor(ip->i_rdev);
vap->va_rminor = uminor(ip->i_rdev);
fsp->rdev = inode.i_rdev;
if (usenumflag || ((name = devname(ip->i_rdev, type)) == NULL))
major(ip->i_rdev), minor(ip->i_rdev));