From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <hijacker@oldum.net>
Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com
 [IPv6:2a00:1450:4864:20::643])
 (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)
 key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256)
 (No client certificate requested)
 by mail.server123.net (Postfix) with ESMTPS
 for <dm-crypt@saout.de>; Sat,  9 May 2020 21:42:03 +0200 (CEST)
Received: by mail-ej1-x643.google.com with SMTP id z5so3492382ejb.3
 for <dm-crypt@saout.de>; Sat, 09 May 2020 12:42:03 -0700 (PDT)
Date: Sat, 9 May 2020 21:41:59 +0200
From: Nikolay Kichukov <hijacker@oldum.net>
Message-ID: <20200509214159.3d85409c@glena.fritz.box>
In-Reply-To: <CAJCQCtQAuhh3aLFa7Sze17wmYqUa=JtPDXMiH7KirJE18Powzg@mail.gmail.com>
References: <20200509162535.13a4086e@glena.fritz.box>
 <CAJCQCtQAuhh3aLFa7Sze17wmYqUa=JtPDXMiH7KirJE18Powzg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: Re: [dm-crypt] luks2 and discard/trim not working
List-Id: <dm-crypt.saout.de>
List-Unsubscribe: <https://www.saout.de/mailman/options/dm-crypt>,
 <mailto:dm-crypt-request@saout.de?subject=unsubscribe>
List-Archive: <https://www.saout.de/pipermail/dm-crypt/>
List-Post: <mailto:dm-crypt@saout.de>
List-Help: <mailto:dm-crypt-request@saout.de?subject=help>
List-Subscribe: <https://www.saout.de/mailman/listinfo/dm-crypt>,
 <mailto:dm-crypt-request@saout.de?subject=subscribe>
To: Chris Murphy <lists@colorremedies.com>
Cc: dm-crypt@saout.de

Hello Chris,

On Sat, 9 May 2020 09:45:13 -0600
Chris Murphy <lists@colorremedies.com> wrote:

> On Sat, May 9, 2020 at 8:28 AM Nikolay Kichukov <hijacker@oldum.net>
> wrote:
> >
> > Hello folks,
> >
> > Recently, I upgraded to LUKS2 on a NVME SSD disk and noticed that
> > fstrim does not work. Surely it was running fine with LUKS1.  
> 
> ...
> 
> > dmsetup table /dev/mapper/root | grep allow
> > 0 947028136 crypt capi:rfc7539(chacha20,poly1305)-random
> > :32:logon:cryptsetup:6ae40ec7-1b4c-40ea-871b-d13c9ae66b92-d0 0
> > 254:0 0 2 allow_discards integrity:28:aead  
> 
> Was the original luksFormat command combined with --integrity option?

yes

> From man cryptsetup: Since dm-integrity doesn't support discards
> (TRIM), dm-crypt device on top of it inherits this, so integrity
> protection mode doesn't support discards either.

Thanks for the direction! It seems like, this is in the pipeline for
dm-integrity, which is to arrive in version 1.6.0 in kernel 5.7:

"allow_discards
Allow block discard requests (a.k.a. TRIM) for the integrity device.
Discards are only allowed to devices using internal hash.
The default is to ignore discard requests.
Available since: 1.6.0 (kernel 5.7)"

source: https://gitlab.com/cryptsetup/cryptsetup/-/wikis/DMIntegrity
 
Does mine use an internal hash?

Thanks,
-Nik