unshare() pid ns

[Serge E. Hallyn]

Quoting Pavel Emelyanov (xemul at openvz.org):
> sukadev at us.ibm.com wrote:
>> Pavel,
>> unshare() of pid ns seems to fail with -EINVAL in 2.6.23-rc3-mm1.
>> I thought we supported it in the earlier patchsets.  I guess
>> I missed that in the review of recent patchsets.
>
> I disabled unsharing of pid namespaces because it's almost
> impossible. Look - you have to reattach all the pids to the
> task with saving its ids as seen in previous namespaces.

We agree, but thought you for some perverse reason preferred unshare to
clone for pidns :)

Thanks for clarifying.

-serge