systemd-shim needs to grow support for abandoncgroup and stopsession

[James Hunt]

The fix for upstart bug 1357252 has highlighted the fact that systemd-shim does not support functionality required by logind, namely:

- abandoncgroup (delete if possible)
- stopsession(kill all tasks and remove cgroup)

Because of this, systemd-shim sets the remove-on-empty bit on all cgroups that are created under the users logind session. As a result, when an upstart user job running under the upstart session init asks cgmanager to create a cgroup, that cgroup is created and inherits the remove-on-empty bit set by systemd-shim.

This can result in failed upstart jobs since when a subsequent job process (a secondary process that runs as part of a single overall upstart job) is started by upstart, it may fail to move the pid into the already-created cgroup since cgmanager may have (just) deleted it.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: systemd-shim 7-1
ProcVersionSignature: Ubuntu 3.16.0-10.15-generic 3.16.1
Uname: Linux 3.16.0-10-generic x86_64
ApportVersion: 2.14.6-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Aug 29 16:21:28 2014
InstallationDate: Installed on 2014-04-11 (139 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Daily amd64 (20140409)
SourcePackage: systemd-shim
UpgradeStatus: Upgraded to utopic on 2014-05-08 (113 days ago)