VTBLK_MIN_SEGMENTS
if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) {
if (sc->vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1)
sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS, /* max # segments */
nsegs = VTBLK_MIN_SEGMENTS;
dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS) *
nreqs /= VTBLK_MIN_SEGMENTS;