From mboxrd@z Thu Jan  1 00:00:00 1970
From: "George Spelvin" <linux@horizon.com>
Subject: Re: Where exactly will arch_fast_hash be used
Date: 7 Dec 2014 08:30:56 -0500
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Thanks for the encouragement!

> Please consider xfs, too.
> AFAIK xfs doesn't seed their hashing so far and the hashing function is
> pretty weak. One example:
> http://marc.info/?l=linux-xfs&m=139590613002926&w=2

Is that something that *can* be changed without breaking the
disk format?  SipHash is explicitly *not* designed to be secure as
an unkeyed hash in the way that SHA-type algorithms are.

What it's designed to do is provide second preimage resistance
of its output, or a function (like modular reduction) of its output,
against an attacker who doesn't know the secret seed.

> Ack. If we want to use it in the networking stack we should be able to
> use it without a dependency to the crypto framework.

Already understood.  My big question is whether a single function call
is okay or we need something inlinable.