Re: fanotify - overall design before I start sending patches

Pavel Machek
2009-08-08T10:36:34Z

On Fri 2009-08-07 13:43:10, Eric Paris wrote:
> On Fri, 2009-08-07 at 18:36 +0200, Miklos Szeredi wrote:
> > On Thu, 06 Aug 2009, Eric Paris wrote:
> > > just work. The whole reason for the timeout is because I don't trust
> > > userspace not to get it wrong and I'd rather not lose my box because of
> > > it.
> >
> > IMO this has nothing to do with userspace(*) and everything to do with
> > complexity. Virus scanning is complex and any such code, whether
> > runing in userspace or not, can easily screw up and freeze the system.
>
> I agree, 'userspace' was not the best term. Let me rephrase:
>
> "The whole reason for the timeout is because I don't trust anything not
> to get it wrong and I'd rather not lose my box because of it."
>
> > The way to solve that is not to implement hacks on the kernel
> > interface, but rather by separating the complex parts and implementing
> > a simple watchdog layer on top of that, that makes sure things don't
> > go wrong.
>
> So you would argue that every fanotify listener implement their own
> watchdog layer that may or may not be correct rather than do a single
> watchdog layer for everyone? And that's better?

Yes.

(You can do library, and maybe you can just make fanotify listener
simple enough. Or you can just scrap the open vetoing [mis]feature).
Pavel

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