vn_renamepath
vn_renamepath(tvp, srcvp, args->to.name,
vn_renamepath(ndvp, srcvp, nnm, nlen - 1);
vn_renamepath(tovp, srcvp, args->rna_to.da_name,
vn_renamepath(tdvp, ZTOV(szp), tnm,
void vn_renamepath(vnode_t *dvp, vnode_t *vp, const char *nm, size_t len);