LUKS root shutdown failure

[Mason Loring Bliss]

I've opened a bug about this, but it seems not to have been looked at yet.

    https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1554795

What's the chance that if I were to do the work to implement a "shutdown-
initrd" it'd make it into Xenial? As things stand, this is breakage in what
was previously a working configuration.

To recap the bug, systemd fails to stop crypto services and defaults to a
90-second timeout when root is on LUKS. The Freenode #systemd people pointed
me to this:

    https://www.freedesktop.org/wiki/Software/systemd/InitrdInterface/

and that says, in part:

    If the executable /run/initramfs/shutdown exists systemd will use it to
    jump back into the initrd on shutdown. /run/initramfs should be a usable
    initrd environment to which systemd will pivot back and the "shutdown"
    executable in it should be able to detach all complex storage that for
    example was needed to mount the root file system.

The documentation (like much of systemd) approaches inscrutability, but my
guess is that they want a complete initrd environment on /run/initramfs based
on this:

    It's the job of the initrd to set up this directory and executable in the
    right way so that this works correctly. The shutdown binary is invoked
    with the shutdown verb as argv[1], optionally followed (in argv[2],
    argv[3], ...) by systemd's original command line options, for example
    --log-level= and similar.

They have a couple more details on the page, but my main point is that this
whole notion of supporting a shutdown initrd seems to be missing from Ubuntu,
and my bug is a case where we seem to actually need it. That said, it's
possible to imagine additional cases that would need similar shutdown-initrd
care. The idea of a shutdown-initrd seems sane and even useful, so I'm
curious if there'd be support for this sort of thing. Time is growing short
for it, though, making me think that Xenial Xerus will, as noted, ship with
breakage in a previously-working configuration.

-- 
Mason Loring Bliss             mason at blisses.org            Ewige Blumenkraft!
(if awake 'sleep (aref #(sleep dream) (random 2))) -- Hamlet, Act III, Scene I