Let's simplify things and drop the logic that /var/lib/machines is setup
as auto-growing btrfs loopback file /var/lib/machines.raw.
THis was done in order to make quota available for machine management,
but quite frankly never really worked properly, as we couldn't grow the
file system in sync with its use properly. Moreover philosophically it's
problematic overriding the admin's choice of file system like this.
Let's hence drop this, and simplify things. Deleting code is a good
feeling.
Now that regular file systems provide project quota we could probably
add per-machine quota support based on that, hence the btrfs quota
argument is not that interesting anymore (though btrfs quota is a bit
more powerful as it allows recursive quota, i.e. that the machine pool
gets an overall quota in addition to per-machine quota).
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This also adds "machinectl import-raw" and "machinectl import-tar" to
wrap these new bus calls.
THe commands basically do for local files that "machinectl pull-raw" and
friends do for remote files.
If /var/lib/machines is mounted as btrfs loopback file system in
/var/lib/machines.raw with this change we automatically grow the file
system as it fills up. After each 10M we write to it during imports, we
check the free disk space, and if the fill level grows beyond 66% we
increase the size of the file system to 3x the fill level (thus lowering
it to 33%).