From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Berg <benjamin-cdvu00un1VgdHxzADdlk8Q@public.gmane.org>
Subject: Re: [BUG] NULL pointer de-ref when setting io.cost.qos on LUKS
 devices
Date: Thu, 05 Mar 2020 11:31:29 +0100
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To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
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On Wed, 2020-03-04 at 11:42 -0500, Tejun Heo wrote:
> [SNIP]
>=20
> Right now, the situation isn't great with dm. When pagecache
> writebacks go through dm, in some cases including dm-crypt, the cgroup
> ownership information is completely lost and all writes end up being
> issued as the root cgroup, so it breaks down when dm is in use.

Fair enough.

> In the longer term, what we wanna do is controlling at physical
> devices (sda here) and then updating dm so that it can maintain and
> propagate the ownership correctly but we aren't there yet.

Perfect, so what I am seeing is really just a small systemd bug. Thansk
for confirming, I'll submit a patch to fix it.

Benjamin

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