stropen
if ((error = stropen(oldvp, &pdev, flag, crp)) != 0) {
if ((error = stropen(oldvp, &pdev, flag, crp)) != 0) {
error = stropen(vp, &newdev, flags, cr);
error = stropen(cvp, &newdev, flag, cr);
extern int stropen(struct vnode *, dev_t *, int, cred_t *);