find_chunknum
chunknum = find_chunknum(d, info, ptr, 0);
find_chunknum(pool, info, p, 0);
find_chunknum(pool, info, p, mopts.chunk_canaries);
chunknum = find_chunknum(pool, info, p, 0);
uint32_t chunknum = find_chunknum(pool, info, p, 0);
chunknum = find_chunknum(pool, chunkinfo, p, 0);