[pkg-cryptsetup-devel] Bug#768314: Bug#768314: cryptsetup: Passphrase prompt rolls by without stopping

[Jonas Meurer]

Hi Tomas,

thanks for taking care of the bugreport.

Am 30.12.2014 um 19:27 schrieb Tomas Pospisek:
> Hello Jonas & Kjetil,
> 
> (context: I'm reading through release-notes bug reports).
> 
> I'm not sure I understand what you are expecting as a result by
> cloning/reassigning this to the release notes -
> 
> Let me try to understand the problem:
> 
> * if there's an encrypted partition, then systemd, who aparently would be
>   responsible to do so will not prompt for the password, if plymouth is
>   not installed.
> 
> Is my understanding of the problem correct?

Yes. Actually, it is even more complicated, but your understanding is
correct:

Systemd includes its own dm-crypt/cryptsetup device unlocking functions.
With systemd as init system, it processes all dm-crypt encrypted devices
that shall be unlocked during the boot process and *after* initramfs.
I don't know systemd, but from the bugreports I learned that it
apparently doesn't implement a proper mechanism to prompt for user input
itself. Instead it relies on plymouth doing that task. As a result,
systemd without plymouth doesn't wait for user input at unlocking
dm-crypt devices but instead continues to print boot logging output to
the console.

> So I think the right thing to do would be, that during the upgrade the
> systemd postinstallation should check whether there are some mounted
> partitions that are crypted and then recommend to install plymouth. Do
> you concur?

I would even go futher and say that systemd should recommend plymouth in
any case. Still, if it's only recommended and not a hard dependency, the
discovered behaviour should be documented in the release notes in my eyes.

> Otherwise, should the release-notes recommend to install plymouth to the
> user if s/he has crypted partitions that should get mounted during boot?

Yes, that's what needs to be done at least.

> Ideally IMHO the release notes should also explain the problem in
> sufficient technical detail to allow the user to take his own steps to
> further understand the problem and to choose an alternative solution if
> he deems so.
> 
> Optimally you could suggest a wording?

Unfortunately I've not enough knowledge about systemd to propose a
wording. But feel free to use anything I wrote in the bugreport for a draft.

Cheers,
 jonas