[systemd-devel] systemd-repart very slow creation of partitions with Encrypt=

[Lennart Poettering]

On Mo, 05.06.23 10:41, Valentin David (valentin.david at canonical.com) wrote:

> On Mon, Jun 5, 2023 at 9:56 AM Lennart Poettering <lennart at poettering.net>
> wrote:
>
> > On So, 04.06.23 14:25, Valentin David (valentin.david at canonical.com)
> > wrote:
> >
> > > I have been trying to create a root partition from initrd with
> > > systemd-repart. The repart.d file for this partition is as follow:
> > >
> > > [Partition]
> > > Type=root
> > > Label=root
> > > Encrypt=tpm2
> > > Format=ext4
> > > FactoryReset=yes
> > >
> > > I am just using systemd-repart.service in initrd, without modification
> > > (that is, it finds the disk from /sysusr/usr). Even though this is
> > working,
> > > the problem I have is that it takes a very long time for the partition to
> > > be created. Looking at the logs, it spends most of time in the
> > > reencryption.
> >
> > reencryption? We don't do any reencrytion really. i.e. we do not
> > actually support anything like "cryptsetup reencrypt" at all. All we
> > do is the equivalent of "cryptsetup luksFormat". Are you suggesting
> > that repart is slower at formatting a block device via LUKS than
> > invoking cryptsetup directly would be? I'd find that very surprising...
> >
>
> This is what it looks like in src/partition/repart.c. Function
> partition_encrypt calls sym_crypt_reencrypt_init_by_passphrase and
> then sym_crypt_reencrypt.
> And make_filesystem is called before partition_encrypt. So it must
> reencrypt since mkfs was called before.

Oh, fuck, yeah, Daan added that.

This is a bug really.

Lennart

--
Lennart Poettering, Berlin