B_DIRECT
bp->b_flags &= ~(B_NOCACHE | B_RELBUF | B_DIRECT);
if (bp->b_flags & B_DIRECT) {
if (tbp->b_flags & B_DIRECT)
bp->b_flags |= B_DIRECT | B_TTC;
bp->b_flags |= B_DIRECT;
bp->b_flags |= B_DIRECT;