B_CKHASH
rabp->b_flags |= B_CKHASH;
bp->b_flags |= B_CKHASH;
if ((bp->b_flags & B_CKHASH) != 0) {
(bp->b_flags & B_CKHASH) != 0 &&
bp->b_flags &= ~B_CKHASH;
bp->b_flags &= ~B_CKHASH;
bp->b_flags &= ~B_CKHASH;