[PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications [ver #5]

[Ian Kent]

On Mon, 2020-08-03 at 13:31 +0100, David Howells wrote:
> Ian Kent <raven at themaw.net> wrote:
> 
> > > I'm changing it so that the fields are 64-bit, but initialised
> > > with the
> > > existing mount ID in the notifications set.  The fsinfo set
> > > changes that
> > > to a unique ID.  I'm tempted to make the unique IDs start at
> > > UINT_MAX+1 to
> > > disambiguate them.
> > 
> > Mmm ... so what would I use as a mount id that's not used, like
> > NULL
> > for strings?
> 
> Zero is skipped, so you could use that.
> 
> > I'm using -1 now but changing this will mean I need something
> > different.
> 
> It's 64-bits, so you're not likely to see it reach -1, even if it
> does start
> at UINT_MAX+1.

Ha, either or, I don't think it will be a problem, there's
bound to be a few changes so the components using this will
need to change a bit before it's finalized, shouldn't be a
big deal I think. At least not for me and shouldn't be much
for libmount either I think.

Ian