Re: [PATCH v2 27/28] ext4: xattr inode deduplication

[Tahsin Erdogan]

> Hmm... normally we'd supply sbi->s_csum_seed as the second argument so
> that the metadata checksum value also has the fs uuid stamped into it.

I have thought about using sbi->s_csum_seed and was a little hesitant
because it involves adding more complexity to e2fsprogs to handle
cases like changing uuid or turning off metadata_csum. After thinking
more about this, I think it is doable.

> Even if you dismiss that, we usually follow the convention of
> initializing the crc32c calculation with (~0U), not (0U), to strengthen
> crc32c's ability to detect zeroes being injected at the start of the
> stream.

Agreed, using ~0 is definitely better than 0.