Messages in this thread | | | Date | Thu, 6 Aug 2009 12:10:59 +0200 | From | Pavel Machek <> | Subject | Re: fanotify - overall design before I start sending patches |
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On Wed 2009-08-05 17:46:16, Tvrtko Ursulin wrote: > On Wednesday 05 August 2009 03:05:34 Pavel Machek wrote: > > BTW my -@suse.cz address no longer works. pavel@ucw.cz should be ok. > > > > > If a FAN_ACCESS_PERM or FAN_OPEN_PERM event is received the listener > > > must send a response before the 5 second timeout. If no response is > > > sent before the 5 second timeout the original operation is allowed. If > > > this happens too many times (10 in a row) the fanotify group is evicted > > > from the kernel and will not get any new events. Sending a response is > > > done using the setsockopt() call with the socket options set to > > > FANOTIFY_ACCESS_RESPONSE. The buffer should contain a structure like: > > > > The timeout part of interface is very ugly. Will fanotify users have > > to be realtime/mlocked? > > Why do you think it is very ugly?
Do I need to explain?
> Just to make sure you haven't missed this - it is not that they have to > complete the whole operation before the timeout period (since you mention > realtime/mlock I suspect this is what you think?), but _during_ the operation > they have to show that they are active by sending something like keep alive > messages. > > Or you are worried about failing to meet even that on a loaded system? There > has to be something like this otherwise hung userspace client would kill the > whole system.
Of course, I'm worried about failing to meet this on loaded system. And the fact that I _have_ to worry about that means that interface is ugly/broken. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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