[CRIU] [PATCHv2 0/3] Support C/R of frozen cgroup

[Eugene Batalov]

This patchset implements c/r of ps tree
that was frozen using freezer controller before start of
ps tree dumping.
Such ps tree will be frozen after restore.
This means that we can c/r paused Docker containers.
See details in issue #20 on github:
https://github.com/xemul/criu/issues/20

We'll send patch with autotest for this feature later.

>From user point of view we extend functionality of --freeze-cgroup
option so CRIU documentation and help message for --freeze-cgroup
option may need some improvement/clarification.

=== v0 to v1 changes ===
Save freezer state not in new cgroup.img field but in existing
cgroup_prop_entry. This should make next changes in freezer c/r
much easier. For example if CRIU supports c/r of complete freezer
hierarchy.

=== v1 to v2 changes ===
- Return error code on restore if freezer controller has >1 root
  freezer cgroup. Runtime assertion was used in v1 in this case.
- One code style fix
- Print message in case of freezer state restore error.
  This is needed because freezer is restored in the moment when
  restore can't fail. We should print message at least.

Evgeniy Akimov (3):
  cgroups: save freezer state during dump
  restore: split finalize_restore into two stages
  restore: restore freezer cgroup state

 cgroup.c         | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 cr-restore.c     | 39 ++++++++++++++++++++++------------
 include/cgroup.h |  1 +
 include/seize.h  |  1 +
 seize.c          |  5 +++++
 5 files changed, 97 insertions(+), 13 deletions(-)

-- 
1.9.1