all_zeroes
for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
for (p=partial;p>chain && all_zeroes((block_t*)p->bh->b_data,p->p);p--)