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

[Pavel Emelyanov]

On 06/24/2014 10:07 AM, Andrew Vagin wrote:
> On Mon, Jun 23, 2014 at 11:28:27PM -0500, Tycho Andersen wrote:
>> On Tue, Jun 24, 2014 at 08:03:25AM +0400, Andrew Vagin wrote:
>>> On Tue, Jun 24, 2014 at 02:29:27AM +0000, Tycho Andersen wrote:
>>>> On Mon, Jun 23, 2014 at 10:53:48PM +0400, Andrew Vagin wrote:
>>>>>
>>>>> Look at my version. It doesn't copy a path in another place.
>>>>
>>>> The copy is sort of unfortunate, strtok writes a null byte to the
>>>> string it is tokenizing, which seems impolite to do as callers won't
>>>> expect it, even though it might not break anything. I used it because
>>>> I prefer using library functions to rolling my own, but I'm happy to
>>>> switch it if the copy is a big issue.
>>>>
>>>> Tycho
>>>>
>>>
>>> The copy isn't a big issue. I don't like strtok:).
>>
>> That's fair :-)
>>
>>> Below you can find a version, which don't modify path in place.
>>
>> It still does modify the string, though, which means you can't pass
> 
> No, it doesn't. It creates a copy in made_path and does that for one
> call and then it modifies this copy.
> 
>> read-only memory to mkdirpat, which might also be a little surprising.
>> Maybe this version with a copy?
> 
> It's up to Pavel.

I think that the library function shouldn't corrupt the string it takes.
And since we don't have read-only memory (yet) it's OK if we modify
the string in place, then restore it back.

But, since cgroup paths are typically short, copying it to another place
doesn't cost much. Thus the simpler code we have, the better it is :)

Thanks,
Pavel