[Devel] [RFC][PATCH] Add child reaper to struct pspace

[Eric W. Biederman]

"Serge E. Hallyn" <serue at us.ibm.com> writes:

> Quoting Eric W. Biederman (ebiederm at xmission.com):
>> 
>> My point being not that we can't get this correct with simple code, but
>> that it is easy to get it wrong.
>
> True.
>
> I should think the list has to go into the struct pid, not the
> task_struct.  There is one struct pid per (pid_ns, pid), so we can keep
> just one simple list to walk the pid_ns processes.  If we were to put it
> in the task_struct, well there's really no clean way to go about it then :)

Exactly.

Add to this that all of the extra struct pids are really something akin
to symlinks and you are redirected to the primary one on lookup and
you see an even bigger slice of the puzzle.  So I'm not really certain
we have additional pids to work with.

readdir in /proc has the same problem (except for the atomic requirement)
and I think I just handled it.

So this is definitely going to be doable but it is something we need
to handle very carefully.

Eric