[systemd-devel] PrivateTmp and systemd-tmpfiles

[Lukáš Nykrýn]

Kay Sievers píše v St 17. 10. 2012 v 18:28 +0200:
> On Wed, Oct 17, 2012 at 6:10 PM, Lennart Poettering
> <lennart at poettering.net> wrote:
> > On Wed, 17.10.12 14:16, Lukáš Nykrýn (lnykryn at redhat.com) wrote:
> >
> >> Hello,
> >> Today I have read this bug
> >> https://bugzilla.redhat.com/show_bug.cgi?id=866693 and described
> >> systemd-tmpfiles behavior look pretty wrong to me, but I am not sure how
> >> to fix it. Some ideas cross my mind; moving systemd-namespace-*
> >> elsewhere, adding some option to exclude dirs in tmpfiles conf files,
> >> stop cleaning /tmp, hardcode some excludes to tmpfiles, but I don't like
> >> any of these solutions.
> >
> > We already allow files to be excluded from clean up by setting the
> > sticky bit on them. We can't do that for dirs however, since the sticky
> > bit for dirs has a different meaning. One possible way to solve this
> > issue otherwise might be by introducing an xattr for this. The one thing
> > blocking this right now however is that tmpfs still can't handle xattrs
> > properly. There were multiple attempts to get xattrs for tmpfs into the
> > kernel, not sure what the latest state on this is.
> >
> > The best would probably be to exclude these dirs from clean-up via
> > explicit tmpfiles lines. Unfortunately "x" is probably not going to do
> > it here, since we actually want recursive clean-up inside the dir, just
> > not of the dir... So maybe introduce a new type of "X" that excludes the
> > dir itself from clean-up but does not exclude recursively?
> 
> Pre-create and protect a  /tmp/systemd-namespace/ subdir?
> 
> Kay

What about saving private tmp and var/tmp paths to service struct when
service is started and then systemd-tmpfiles can obtain all currently
used paths and skip them (but not their content)?

I don't think that simply skip /tmp/systemd-privat-XXX would be a good
idea because these dirs would be never deleted even if the service is
already dead.

Lukas