From: Milan Broz <gmazyland@gmail.com>
To: Jasper Surmont <surmontjasper@gmail.com>, cryptsetup@lists.linux.dev
Subject: Re: dm-verity setup on loop device
Date: Thu, 7 Apr 2022 12:05:44 +0200 [thread overview]
Message-ID: <b59b57b6-1468-1041-bdbd-ec9399329dd2@gmail.com> (raw)
In-Reply-To: <CAH4tiUt1_1B64=QgU7uXmnBZZw=4FYEHtN=rZcx-zANJSbaYSQ@mail.gmail.com>
On 07/04/2022 11:40, Jasper Surmont wrote:
> While trying to understand the dm-verity code, I tried making a small
> verity setup. I created 1 readonly loop device and 1 non-readonly loop
> device. When I then try to create the verity target with the readonly
> as data device (not using veritysetup because I want to experiment on
> a low level), dmesg still says that the device is not in readonly
> mode.
>
> Is it possible what I'm trying to achieve?
Yes, it should be possible.
(If you have device with Merkle-tree already prepared, if not, it will only
activate in failed state - but it will allow creation of the DM device.)
And if you post the exact command you are trying,
maybe we can show you where is the problem :-)
Both devices should be read only (dm-verity cannot be mapped for writes)
and I guess you need to call dmsetup with -r (--readonly) option.
Milan
next prev parent reply other threads:[~2022-04-07 10:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-07 9:40 dm-verity setup on loop device Jasper Surmont
2022-04-07 10:05 ` Milan Broz [this message]
2022-04-07 11:42 ` Jasper Surmont
2022-04-07 12:15 ` Milan Broz
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