Re: Re: Make /tmp/ a tmpfs and cleanup /var/tmp/ on a timer by default [was: Re: systemd: tmpfiles.d not cleaning /var/tmp by default]

[Sam Hartman <hartmans@debian.org>]

>>>>> "Johannes" == Johannes Schauer Marin Rodrigues <josch@debian.org> writes:
    >> > > If [files can be deleted automatically while mmdebstrap is using them],
    >> > > how should applications guard against that from
    >> > > happening?
    >> >
    >> > As documented in tmpfiles.d(5), if mmdebstrap takes out an exclusive
    >> > flock(2) lock on its chroot's root directory, systemd-tmpfiles should
    >> > fail to take out its own lock on the directory during cleanup, and
    >> > respond to that by treating the directory as "in use" and skipping it.
    >> 
    >> That also works, but only as long as mmdebootstrap is actually
    >> running, and as far as I understand it is not a long-running service,
    >> not sure if it works for this use case

Note that according to the man page, ctime is used as well as mtime.
So for roots that are actually temporary, I don't think much needs to be
done.
It won't matter that the mtime might be old because the ctime should be
consistent with when the root is unpacked.

I do wish there were a way to specify for /var/tmp that directories
under /var/tmp should be deleted in their entirety or entirely left
alone.
I realize we'd have a big debate about whether that was a good default,
but I'd find it useful for my systems at least.