Comment # 27 on bug 966255 from Jacob W

Thank you Fabian for your quick replies.

(In reply to Fabian Vogt from comment #26)
> (In reply to Jacob W from comment #25)
> > Created attachment 667207 [details]
> > cryptsetup boot password prompt goes into background as a job
> 
> That's not the plymouth prompt, so a totally different issue.
> It didn't even try to use plymouth for password asking.

This is when booting without kernel options "splash=silent" and "quiet". So of
course plymouth is not started, because it's not supposed to. The point of this
screenshot is to show that even without plymouth, the password prompting is
incorrect.

If I do have the above kernel options enabled, I do not get a splash screen.
All I get is a blank black screen. VT switching does not work. This blank black
screen shows up where previously, prior to this bug, I would get the plymouth
password prompt.

> 
> > Password prompt is not shown and plymouth theme never shows up, instead it freezes the system where VT switching does not work.
> 
> If even the cursor stops blinking, the kernel either froze or panics ->
> kernel bug.

Logs show no mention of kernel panic. Kernel loads fine from what I can tell.
Have not had a kernel panic since I started having this cryptsetup issue. I've
check both /var/log/messages and systemd journald.

> To confirm, run on a booted system as root on a TTY:
> 
> > rcxdm stop
> > plymouthd --no-daemon --no-boot-log --tty=/dev/tty0 --debug --mode=boot
> 
> and on a different tty also as root
> 
> > plymouth show-splash
> 
> and you should the the splash screen (on TTY7).

I do not see the splash screen. All I see is the regular output of booting:
[ OK ] ....
[ OK ] ....

No errors, nothing unusual, no interruptions, etc. None of the above commands
showed errors from what I could tell.

> 
> > Forcing the system to boot without plymouth (press e on grub's kernel list) shows what looks like cryptsetup trying to prompt for the password, but instead instantly being backgrounded as a job. After more processes go through their boot procedure, the boot process stops and looks frozen. If I press a button on the keyboard, it forces the password prompt to re-appear. Now I can enter my password and everything works from there.
> 
> It's not backgrounded, it's the current TTY so systemd uses it, although
> it's also being used by something else... -> systemd bug(?)

Exactly! The password prompt should halt all further processes until the
correct password is entered, but this is not the case. The password prompt is
suppressed and other things just keep loading. I call this backgrounding,
because that's exactly how it looks like: the job (it's literally called that)
of cryptsetup password prompt is being suppressed. Hitting a button later
"reveals" the job (to me, that's like foregrounding it). Maybe that's bad use
of terminology.

Yes, this looks like a systemd bug. I've been trying to say that from the
beginning. Isn't this bug report a systemd issue? I'm confused. 

Like I mentioned before, I do not think plymouth is to blame, but systemd
because even without plymouth, there is an issue with the password prompt (see
previously attached screenshot).

See also (like you already have) my comments on bug 942940

To recap:
1) without kernel options "splash=silent" and "quiet", it's clear cryptsetup
password prompt is not being correctly initiated (see previously attached
screenshot).
2) with kernel option "quiet" but NOT "splash=silent" (or with
"splash=verbose"), password prompt is correctly shown and halts everything
until a correct password is provided. Once provded, everything continues to
load. This is how it's supposed to work.
3) with both "splash=silent" and "quiet", the instance plymouth is supposed
show the password prompt, what I assume is the graphical system freezes and all
I get is a blank black screen. I cannot switch VT.

>From the above, I am guessing that this is a systemd issue. When using
plymouth, it is getting two conflicting "signals": 1) the passowrd prompt is
needed and 2) don't show password prompt. This is exactly what happens without
kernel options "splash=silent" and "quiet" (see previously attached
screenshot): cryptsetup is asked to show password prompt and 2) the password
prompt is not shown / hidden (I call this the job being backgrounded). But
because there is no plymouth being loaded, the system does not freeze and you
wait until other things load, press a button on the keyboard, and the password
prompt is then foregrounded.