[CRIU] [PATCH 1/2] Re-create cgroups if necessary

[Pavel Emelyanov]

On 06/24/2014 05:38 PM, Tycho Andersen wrote:
> Hi Pavel,
> 
> On Tue, Jun 24, 2014 at 10:53:26AM +0400, Pavel Emelyanov wrote:
>> On 06/23/2014 07:54 PM, Tycho Andersen wrote:
>>> If a task had cgroups, these should be restored. (Also any properties of
>>> cgroups, but this commit doesn't do that yet.)
>>>
>>> Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
>>> ---
>>>  cgroup.c       |  6 +++++-
>>>  include/util.h |  5 +++++
>>>  util.c         | 26 ++++++++++++++++++++++++++
>>>  3 files changed, 36 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/cgroup.c b/cgroup.c
>>> index 2d9ebad..8b2deb2 100644
>>> --- a/cgroup.c
>>> +++ b/cgroup.c
>>> @@ -258,9 +258,13 @@ static int move_in_cgroup(CgSetEntry *se)
>>>  		int fd, err;
>>>  		ControllerEntry *ce = se->ctls[i];
>>>  
>>> +		sprintf(aux, "%s/%s", ce->name, ce->path);
>>> +		if (mkdirpat(cg, aux) < 0)
>>> +			return -1;
>>> +
>>>  		sprintf(aux, "%s/%s/tasks", ce->name, ce->path);
>>>  		pr_debug("  `-> %s\n", aux);
>>> -		err = fd = openat(cg, aux, O_WRONLY);
>>> +		err = fd = openat(cg, aux, O_WRONLY | O_CREAT, 0700);
>>
>> Why O_CREAT here? The cgroup files should just exist.
> 
> I guess it won't exist if the directory is created by mpdirpat above,

It should, since it's cgroupfs, which populates directories with
files once they are created. And the "tasks" file is one of such.

Thanks,
Pavel