Re: [ckrm-tech] [PATCH 0/2] resource control file system - aka containers on top of nsproxy!

[ebiederm@xmission.com (Eric W. Biederman)]

"Paul Menage" <menage@google.com> writes:

> On 3/7/07, Eric W. Biederman <ebiederm@xmission.com> wrote:
>> The real trick is that I believe these groupings are designed to be something
>> you can setup on login and then not be able to switch out of.
>
> That's going to to be the case for most resource controllers - is that
> the case for namespaces? (e.g. can any task unshare say its mount
> namespace?)

With namespaces there are secondary issues with unsharing.  Weird things
like a simple unshare might allow you to replace /etc/shadow and thus
mess up a suid root application.

Once people have worked through those secondary issues unsharing of
namespaces is likely allowable (for someone without CAP_SYS_ADMIN).
Although if you pick the truly hierarchical namespaces the pid
namespace unsharing will simply give you a parent of the current
namespace.

For resource controls I expect unsharing is likely to be like the pid
namespace.  You might allow it but if you do you are forced to be a
child and possible there will be hierarchy depth restrictions.
Assuming you can implement hierarchical accounting without to much
expense.



Eric