Date: Mon, 8 Nov 2010 00:05:09 +0100
From: Andi Kleen <andi@firstfloor.org>
To: Milan Broz <mbroz@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>, Matt <jackdachef@gmail.com>,
        Linux Kernel <linux-kernel@vger.kernel.org>, dm-devel@redhat.com,
        htd@fancy-poultry.org
Subject: Re: [PATCH] DM-CRYPT: Scale to multiple CPUs v3 on 2.6.37-rc* ?
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On Sun, Nov 07, 2010 at 10:39:23PM +0100, Milan Broz wrote:
> On 11/07/2010 08:45 PM, Andi Kleen wrote:
> >> I read about barrier-problems and data getting to the partition when
> >> using dm-crypt and several layers so I don't know if that could be
> >> related
> > 
> > Barriers seem to be totally broken on dm-crypt currently.
> 
> Can you explain it?

e.g. the btrfs mailing list is full of corruption reports
on dm-crypt and most of the symptoms point to broken barriers.

> Barriers/flush change should work, if it is broken, it is not only dm-crypt.
> (dm-crypt simply relies on dm-core implementation, when barrier/flush
> request come to dmcrypt, all previous IO must be already finished).

Possibly, at least it doesn't seem to work.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.
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