tmp = is->types[type].freelist;
is->types[type].freelist = block;
if (bf_write(is->types[type].bf, block, 0, sizeof(tmp), &tmp) < 0)
{
tmp = is->types[type].freelist;
is->types[type].freelist = block;
if (bf_write(is->types[type].bf, block, 0, sizeof(tmp), &tmp) < 0)
{