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

From	Tahsin Erdogan <tahsin@google.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 27/28] ext4: xattr inode deduplication
Date	2017-06-02 14:50 +0200
Message-ID	<tNUbD-1bn-1@gated-at.bofh.it> (permalink)
References	<tNem7-73N-31@gated-at.bofh.it> <tNkrw-2Bv-3@gated-at.bofh.it> <tNNDc-4UD-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

> 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.

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH v2 27/28] ext4: xattr inode deduplication Tahsin Erdogan <tahsin@google.com> - 2017-06-02 14:50 +0200
  Re: [PATCH v2 27/28] ext4: xattr inode deduplication "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-06-02 20:10 +0200

csiph-web