Re: [take2] Inotify: nested attributes support.

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 26 Nov 2008 10:42:39 +0300 Evgeniy Polyakov <zbr@ioremap.net> wrote:

> Hi Andrew.
> 
> On Tue, Nov 25, 2008 at 04:24:34PM -0800, Andrew Morton (akpm@linux-foundation.org) wrote:
> > I guess I'm being more than usually thick, but I don't understand what
> > this is all about, why it was implemented, what value it provides to
> > users, etc, etc?  Why do I want scalable nested attributes in inotify??
> 
> Originally I just wanted to have a PID value in the inotify events, so
> reused cookie for that, but people rather vocally rised against this. So
> solution is to extend its structure. It would be possible just to add
> couple more bytes and store data there, but if we will want to add some
> more data into event later, we will have to implement inotify3 and so
> on. So I implemented a way to put essentially any number of new and old
> events in any order, turn then on and off, and do not care about
> possible limitation of the structure. As example I added PID, TID,
> write IO start/size and name attributes.

OK, so we have a super-duper framework which will allow us to add pids
(and other things) to inotify messages.

This still doesn't provide a reason for anyone to be interested in the
code!  Why do we want pids in inotify messages?

And how does this work give that pids are (no longer) system-wide unique?

> > I'm buried in patches which I don't understand lately, and having
> > hundreds of people send patches at one guy who doesn't understand them
> > isn't a good system.  Eric Paris is working on inotify-type things as
> > well.  It would be neat if you guys were to understand and review each
> > other's work.  Please.
> 
> No problem, I will review patches if added to the copy. I'm not
> subscsribed to linux-kernel@ so will miss them otherwise.

Thanks.