nfs4_get_otw_cred
cred_otw = nfs4_get_otw_cred(cr, VTOMI4(vp), oop);
*cred_otw = nfs4_get_otw_cred(search_cr, VTOMI4(vp), NULL);
cred_otw = nfs4_get_otw_cred(cr, mi, oop);
cred_otw = nfs4_get_otw_cred(cr, mi, osp->os_open_owner);
extern cred_t *nfs4_get_otw_cred(cred_t *, mntinfo4_t *, nfs4_open_owner_t *);