[PATCH] [RFC] c/r: Add UTS support

[Oren Laadan]

Daniel Lezcano wrote:
> Dan Smith wrote:
>> NL> I'd like there to be some discussion about this, because namespace
>> NL> creation seems like a significant addition to the semantics of
>> NL> restart as I understand it.
>>
>> Indeed.
>>
>> NL> Is namespace creation during restart unavoidable, or merely
>> NL> desirable?  Is there a case for requiring the user to provide a
>> NL> suitable namespace environment before attempting restart?
>>
>> Information about the namespaces has to be saved at checkpoint time no
>> matter what, right?  I guess I don't see any compelling reason to not
>> have the restart operation replicate the environment of the original
>> process.  Otherwise we require userspace to read and interpret the
>> checkpoint stream and selectively feed the bits that the kernel is
>> responsible for to the kernel and process the rest itself (or have the
>> kernel ignore those records).
>>   
> 
> Assuming you have a process and this one unshared the network 100 times 
> and each time opens a socket, how do you checkpoint these namespaces ?
> 
>> What's the argument for depending on userspace to set this up?
>>   
> Maybe, CR of the namespaces is more complicate topic than it looks like 

s/Maybe/Surely/ ...

> and the CR itself is big enough to not complicate things. IMHO, I would 
> recommend as the first step to forbid the unshare inside a container and 
> let the container implementation to save the configuration with the 
> statefile in order to recreate it at the restart
> 

Agreed.

Oren.