Virtualization - Apr 2019 - [PATCH net v5] failover: allow name change on IFF_UP slave interfaces

On Tue, 2 Apr 2019 15:23:29 -0700
si-wei liu <si-wei.liu at oracle.com> wrote:
> On 4/2/2019 2:53 PM, Stephen Hemminger wrote:
> > On Mon,  1 Apr 2019 19:04:53 -0400
> > Si-Wei Liu <si-wei.liu at oracle.com> wrote:
> >  
> >> +	if (dev->flags & IFF_UP &&
> >> +	    likely(!(dev->priv_flags & IFF_FAILOVER_SLAVE)))  
> > Why is property limited to failover slave, it would make sense for
netvsc
> > as well. Why not make it a flag like live address change?  
> Well, netvsc today is still taking the delayed approach meaning that it 
> is incompatible yet with this live name change flag if need be. ;-)
> 
> I thought Sridhar did not like to introduce an additional 
> IFF_SLAVE_RENAME_OK flag given that failover slave is the only consumer 
> for the time being. Even though I can get it back, patch is needed for 
> netvsc to remove the VF takeover delay IMHO.
> 
> Sridhar, what do you think we revive the IFF_SLAVE_RENAME_OK flag which 
> allows netvsc to be used later on? Or maybe, IFF_LIVE_RENAME_OK for a 
> better name?
> 
> -Siwei
I would name it IFF_LIVE_NAME_CHANGE to match IFF_LIVE_ADDR_CHANGE
there is no reason its use should be restricted to SLAVE devices.

On 4/2/2019 8:14 PM, Stephen Hemminger wrote:
> On Tue, 2 Apr 2019 15:23:29 -0700
> si-wei liu <si-wei.liu at oracle.com> wrote:
> 
>> On 4/2/2019 2:53 PM, Stephen Hemminger wrote:
>>> On Mon,  1 Apr 2019 19:04:53 -0400
>>> Si-Wei Liu <si-wei.liu at oracle.com> wrote:
>>>   
>>>> +	if (dev->flags & IFF_UP &&
>>>> +	    likely(!(dev->priv_flags & IFF_FAILOVER_SLAVE)))
>>> Why is property limited to failover slave, it would make sense for
netvsc
>>> as well. Why not make it a flag like live address change?
>> Well, netvsc today is still taking the delayed approach meaning that it
>> is incompatible yet with this live name change flag if need be. ;-)
>>
>> I thought Sridhar did not like to introduce an additional
>> IFF_SLAVE_RENAME_OK flag given that failover slave is the only consumer
>> for the time being. Even though I can get it back, patch is needed for
>> netvsc to remove the VF takeover delay IMHO.
>>
>> Sridhar, what do you think we revive the IFF_SLAVE_RENAME_OK flag which
>> allows netvsc to be used later on? Or maybe, IFF_LIVE_RENAME_OK for a
>> better name?
>>
>> -Siwei
> 
> I would name it IFF_LIVE_NAME_CHANGE to match IFF_LIVE_ADDR_CHANGE
> there is no reason its use should be restricted to SLAVE devices.
>
Stephen,
May be you should consider moving netvsc to use the net_failover driver now?

On Tue, 2 Apr 2019 22:22:18 -0700
"Samudrala, Sridhar" <sridhar.samudrala at intel.com> wrote:
> On 4/2/2019 8:14 PM, Stephen Hemminger wrote:
> > On Tue, 2 Apr 2019 15:23:29 -0700
> > si-wei liu <si-wei.liu at oracle.com> wrote:
> >   
> >> On 4/2/2019 2:53 PM, Stephen Hemminger wrote:  
> >>> On Mon,  1 Apr 2019 19:04:53 -0400
> >>> Si-Wei Liu <si-wei.liu at oracle.com> wrote:
> >>>     
> >>>> +	if (dev->flags & IFF_UP &&
> >>>> +	    likely(!(dev->priv_flags &
IFF_FAILOVER_SLAVE)))
> >>> Why is property limited to failover slave, it would make sense
for netvsc
> >>> as well. Why not make it a flag like live address change?  
> >> Well, netvsc today is still taking the delayed approach meaning
that it
> >> is incompatible yet with this live name change flag if need be.
;-)
> >>
> >> I thought Sridhar did not like to introduce an additional
> >> IFF_SLAVE_RENAME_OK flag given that failover slave is the only
consumer
> >> for the time being. Even though I can get it back, patch is needed
for
> >> netvsc to remove the VF takeover delay IMHO.
> >>
> >> Sridhar, what do you think we revive the IFF_SLAVE_RENAME_OK flag
which
> >> allows netvsc to be used later on? Or maybe, IFF_LIVE_RENAME_OK
for a
> >> better name?
> >>
> >> -Siwei  
> > 
> > I would name it IFF_LIVE_NAME_CHANGE to match IFF_LIVE_ADDR_CHANGE
> > there is no reason its use should be restricted to SLAVE devices.
> >  
> Stephen,
> May be you should consider moving netvsc to use the net_failover driver
now?
> 
NO

Why would I waste time doing that when there is a working and cleaner solution
that is working across 4 OS's and three versions of five major
distributions?