Re: [PATCH net-next 3/6] net: bridge: break if __br_mdb_del fails

[Nikolay Aleksandrov]

On 5/18/17 6:08 PM, Vivien Didelot wrote:
> Hi Nikolay,
>
> Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx> writes:
>
> > >    			err = __br_mdb_del(br, entry);
> > > -			if (!err)
> > > -				__br_mdb_notify(dev, p, entry, RTM_DELMDB);
> > > +			if (err)
> > > +				break;
> > > +			__br_mdb_notify(dev, p, entry, RTM_DELMDB);
> > >    		}
> > >    	} else {
> > >    		err = __br_mdb_del(br, entry);
> >
> > This can potentially break user-space scripts that rely on the best-effort
> > behaviour, this is the normal "delete without vid & enabled vlan filtering".
> > You can check the fdb delete code which does the same, this was intentional.
> >
> > You can add an mdb entry without a vid to all vlans, add a vlan and then try
> > to remove it from all vlans where it is present - with this patch obviously
> > that will fail at the new vlan.
>
> OK good to know. That intention wasn't obvious. I can make __br_mdb_del
> return void instead? What about the rest of the patchset if I do so?
>
> Thanks,
>
>          Vivien

If you make it return void we will not be able to return proper error value
when doing a single operation (the else case). About the rest I see only some
minor style issues, I'll comment on the respective patches. Another minor nit is 
using switch() instead of if/else for the message types but that is really up to 
you, I don't mind either way. :-)

Cheers,
 Nik