From: Milan Broz <gmazyland@gmail.com>
To: Piergiorgio Sartor <piergiorgio.sartor@nexgo.de>,
cryptsetup@lists.linux.dev
Subject: Re: luks2 + integrity + discard
Date: Mon, 20 Jul 2026 22:28:27 +0200 [thread overview]
Message-ID: <1ddcf551-ae22-4677-9910-37aee6895422@gmail.com> (raw)
In-Reply-To: <al4RjyA894rnZxAK@lazy.lzy>
On 7/20/26 2:16 PM, Piergiorgio Sartor wrote:
> Hello,
>
> I'm quite puzzled about the, apparently,
> missing support of discard (or trim) in
> case of encryption with integrity.
>
> From what I understand, which might be
> very wrong, both the encryption layer
> and dm-integrity should support discard.
>
> Reading the documentation does not really,
> at least for me, clarify what is the
> reason why it should not be possible to
> have encryption + integrity + discard.
>
> On the other hand, in case of integrity
> under the raid, with lvm and luks2 on
> top, it seems possible to have discard.
>
> Can someone provide some clarification
> on this?
Discard (TRIM) is supported for dm-integrity
standalone mode. It is also supported for dm-crypt
standalone.
It is not supported for stacked dm-crypt over dm-integrity
(In authenticated encryption mode where dm-integrity only provides
interleaved metadata sectors for dm-crypt.)
(And it never will be implemented for this case.)
Milan
next prev parent reply other threads:[~2026-07-20 20:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-20 12:16 luks2 + integrity + discard Piergiorgio Sartor
2026-07-20 20:28 ` Milan Broz [this message]
2026-07-20 20:36 ` Piergiorgio Sartor
2026-07-20 21:03 ` Milan Broz
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