BFDIRTY
bp->b_flag |= BFDIRTY;
if ((bp->b_flag & (BFCHG | BFDIRTY)) == 0)
bp->b_flag |= BFDIRTY;
if ((bp->b_flag & (BFDIRTY | BFIGNDIRTY)) == BFDIRTY) {
bp->b_flag &= ~BFDIRTY;
bp->b_flag &= ~(BFIGNDIRTY | BFDIRTY);
curbp->b_flag |= BFDIRTY;