Re: [PATCH 2/4] fanotify: Add pids to events

From: Matt Helsley
Date: Sat Jan 16 2010 - 22:44:23 EST


On Sat, Jan 16, 2010 at 11:53:45PM +0100, Andreas Gruenbacher wrote:
> On Friday 15 January 2010 10:21:46 pm Matt Helsley wrote:
> > On Fri, Jan 15, 2010 at 04:12:09PM +0100, Andreas Gruenbacher wrote:
> > > > 2. If the event recipient does a clone and enters a new pidns the pid
> > > > number will be incorrect without any indication.
> > >
> > > No, if a process has a pid within the listener's namespace the listener
> > > will see this pid; otherwise, the resulting pid value is 0.
> >
> > So the pid reference is resolved at read(), correct? If so then that's
> > fine. (Otherwise I'd think the values could still become stale).
>
> Yes. Note that for non-blocking events, there is no guarantee that the
> triggering process still runs when the event is consumed though.

Holding the reference until the event is read ensures the pid
won't be reused in that namespace, so I think that's fine.

Cheers,
-Matt Helsley
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