init: mount /var instead of systemd var.mount service

[MilhouseVH]

Based on suggestion from @stefansaraev: #1469 (comment)

[MilhouseVH]

@stefansaraev this looked like a good idea but systemd continues to unmount /var during shutdown (while lock files are open)... systemd automatically manages all mount points present at runtime (ie. mounted by init) based on /proc/self/mountinfo - see man systemd.mount.

This is systemctl status var.mount on a system with this PR:

NUC:~ # systemctl status var.mount
● var.mount - /var
   Loaded: loaded (/proc/self/mountinfo)
   Active: active (mounted) since Thu 2017-04-20 08:55:04 BST; 24min ago
    Where: /var
     What: none
   CGroup: /system.slice/var.mount

Any thoughts on how to prevent systemd from unmounting /var? noauto as a mount option might work, but busybox doesn't understand it...

Otherwise the original solution, while ugly, worked and ensured /var would be unmounted after all dependencies has been stopped.

[stefansaraev]

stupid thing. the generated var.mount has no DefaultDependencies=no now so that happens.. even more pain indeed. keep it as it was. and sorry for the noise.

honestly I dont know why would systemd would ever try umounting tmpfs mounts on shutdown EDIT: before it stopped all services, or do you perhaps have too many services with defaultdependencies=no?

I am happy that I dont have to use systemd now /me runs ;)

[MilhouseVH]

No worries, worth a try and I learned something new (and unpleasant) about Systemd!