vtodv
if (vtodv(vp, &dvp, CRED(), TRUE) != 0)
return (vtodv(dvp, vpp, cr, TRUE));
(void) vtodv(vp, &dvp, cred_otw, FALSE);
if ((error = vtodv(open_vp, &dvp, cr, TRUE)) != 0)
if ((error = vtodv(*vpp, &dvp, cr, TRUE)) != 0)
extern int vtodv(vnode_t *, vnode_t **, cred_t *, bool_t);