[Devel] Re: [PATCH 3/7] Containers (V8): Add generic multi-subsystem API to containers

[Paul Menage]

On 4/6/07, Srivatsa Vaddagiri <vatsa at in.ibm.com> wrote:
> On Fri, Apr 06, 2007 at 04:32:24PM -0700, menage at google.com wrote:
> > +static int attach_task(struct container *cont, struct task_struct *tsk)
> >  {
>
> [snip]
>
> > +     task_lock(tsk);
>
> You need to check here if task state is PF_EXITING and fail with
> -ESRCH if so? Otherwise we risk breaking refcount on
> init_container_group.
>

Yes, I think you're right; I've now changed it to this in my tree:

        task_lock(tsk);
        if (tsk->flags & PF_EXITING) {
                task_unlock(tsk);
                put_container_group(newcg);
                return -ESRCH;
        }
        rcu_assign_pointer(tsk->containers, newcg);
        task_unlock(tsk);

Thanks,

Paul