RUMP_VOP_WRITE
rv = RUMP_VOP_WRITE(vp, uio, ioflag, cred);
rv = RUMP_VOP_WRITE(devvp, uio, 0, rootcred);
rv = RUMP_VOP_WRITE(devvp, uio, 0, rootcred);
int RUMP_VOP_WRITE(struct vnode *, struct uio *, int, struct kauth_cred *);