Include initrd mounts in the final system also

[r-vdp]

Without this, things like RequiresMountsFor do not work correctly during shutdown.

See systemd/systemd#34327

Fixes #2

[WilliButz]

It seems like this change would re-introduce the ordering cycle for var-log.mount, systemd-journal-flush.service, and systemd-tmpfiles-setup.service (described in TODO.md).

Adding an entry in the integration test for /var/log with inInitrd=true should cause log messages about the ordering cycle to appear.

I'm not sure yet how to resolve this, other than the solution described at the end of the linked file.

[r-vdp]

I booted my system with this and didn't get any mention of a cycle in my logs.

[r-vdp]

The mount is still set up in initrd as before, it's just that we include the unit in the final system as well so that systemd takes it into account and uses the right ordering when unmounting.
Nothing gets remounted or such.

[WilliButz]

I booted my system with this and didn't get any mention of a cycle in my logs

I just pushed another branch based on yours where /var/log is also preserved in the test, here you can see the log messages that show the described ordering cycle:
https://github.com/WilliButz/preservation/actions/runs/10808159129/job/29980512998#step:5:1813

[r-vdp]

It's so weird that I don't have that cycle on my systems, I just checked again. I have the whole shutdown sequence in the logs and there's no mention of any cycle. I will try to find out what is different, something in my config must be preventing this cycle. I'm running nixos-unstable (with a bunch of unmerged PRs patched in).

I already notice that actually now there isn't any mention of unmounting /var/log or /var/lib on shutdown of my machine, neither of stopping systemd-journal-flush. They might only get unmounted after the journal already stopped, since the last message that I have is "Journal stopped".

[WilliButz]

This should be solved by 97104c0.
Now /var/log is also included in the test and it no longer needs inInitrd = true to avoid the ordering cycle.

[r-vdp]

Cool, I'll give that a try, thanks for your work on this!

[r-vdp]

Seems to be working well now, thanks!