Re: [PATCH nf-next 1/3] netfilter: nf_tables: add generation mask to table objects

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Mon, Aug 10, 2015 at 09:56:46AM +0200, Patrick McHardy wrote:
> On 06.08, Pablo Neira Ayuso wrote:
> > On Wed, Aug 05, 2015 at 11:09:16AM +0200, Patrick McHardy wrote:
[...]
> > > > - preparation phase -
> > > > delete table y
> > > > create table y
> > > > create set x
> > > > - commit phase -
> > > > send NEWGEN, attribute type: begin
> > > > delete table y
> > > > create table y
> > > > create set x
> > > > send NEWGEN, attribute type: end
> > > > 
> > > > Thanks for your feedback!
> > > 
> > > That might work if the message ordering is then guaranteed. However I think
> > > we can fix this case without changing NEWGEN. Let me think about that a bit,
> > > for now just taking care of the genid checks correctly seems like a good
> > > step forward.
> > 
> > But we can catch this problem through ->res_id, OK?
> 
> I guess we could with a unique res_id per object, but how would this work
> with multiple object types? Any change bumps res_id, so we'd invalidate
> the full dump for any change.

I see, if we want to be able to invalidate caches at per-object level,
then I think we have to recover the idea of having a netlink attribute
for the per-object generation counter.