[Devel] Re: [PATCH linux-cr] nested pid namespaces (v2)

Louis Rilling Louis.Rilling at kerlabs.com
Mon Mar 22 23:41:41 PDT 2010


On Mon, Mar 22, 2010 at 12:57:35PM -0700, Matt Helsley wrote:
> On Mon, Mar 22, 2010 at 09:38:00AM -0500, Serge E. Hallyn wrote:
> > Quoting Louis Rilling (Louis.Rilling at kerlabs.com):
> > > On Fri, Mar 19, 2010 at 04:39:55PM -0500, Serge E. Hallyn wrote:
> > > > Support checkpoint and restart of tasks in nested pid namespaces.  At
> 
> <snip>
> 
> > > It would probably be safer too to use task_active_pid_ns() instead of
> > > task->nsproxy->pid_ns, just in case some PID namespace unsharing like proposed
> > > by Eric makes it to mainline.
> > 
> > The task is frozen though so it shouldn't be able to unshare while being
> > checkpointed, right?  But it's probably better code anyway.
> 
> By the time it reaches checkpoint a frozen task is in the refrigerator
> -- most often in the signal delivery portion of syscall return. So it can't
> be making any new unshare/setns syscalls and any changes to the namespaces
> should be visible.

And what about a task having already unshared its pid namespace (from within
the container)? In this case, all pid-related stuff should be based on
task_active_pid_ns(), and ->nsproxy->pid_ns should be recorded too to correctly
restore pid unsharing.

Thanks,

Louis

-- 
Dr Louis Rilling			Kerlabs
Skype: louis.rilling			Batiment Germanium
Phone: (+33|0) 6 80 89 08 23		80 avenue des Buttes de Coesmes
http://www.kerlabs.com/			35700 Rennes
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: Digital signature
URL: <http://lists.openvz.org/pipermail/devel/attachments/20100323/f73e822a/attachment-0001.sig>
-------------- next part --------------
_______________________________________________
Containers mailing list
Containers at lists.linux-foundation.org
https://lists.linux-foundation.org/mailman/listinfo/containers


More information about the Devel mailing list