Subject: Re: [PATCH net-next v9 2/4] net: Introduce generic failover module

From: "Michael S. Tsirkin" <[email-masked]>
Date: Wed, 2 May 2018 23:30:02 +0300

On Wed, May 02, 2018 at 10:51:12AM -0700, Samudrala, Sridhar wrote:
> 
> 
> On 5/2/2018 9:15 AM, Jiri Pirko wrote:
> > Sat, Apr 28, 2018 at 11:06:01AM CEST, [email-masked] wrote:
> > > Fri, Apr 27, 2018 at 07:06:58PM CEST, [email-masked] wrote:
> > [...]
> > 
> > 
> > > > +
> > > > +	err = netdev_rx_handler_register(slave_dev, net_failover_handle_frame,
> > > > +					 failover_dev);
> > > > +	if (err) {
> > > > +		netdev_err(slave_dev, "can not register failover rx handler (err = %d)\n",
> > > > +			   err);
> > > > +		goto err_handler_register;
> > > > +	}
> > > > +
> > > > +	err = netdev_upper_dev_link(slave_dev, failover_dev, NULL);
> > > Please use netdev_master_upper_dev_link().
> > Don't forget to fillup struct netdev_lag_upper_info - NETDEV_LAG_TX_TYPE_ACTIVEBACKUP
> > 
> > 
> > Also, please call netdev_lower_state_changed() when the active slave
> > device changes from primary->backup of backup->primary and whenever link
> > state of a slave changes
> > 
> Sure. will look into it.  Do you think this will help with the issue
> you saw with having to change mac on standy twice to get the init scripts
> working? We are now going to block changing the mac on both standby and
> failover.
> 
> Also, i was wondering if we should set dev->flags to IFF_MASTER on failover
> and IFF_SLAVE on primary and standby.

We do need a way to find things out, that's for sure.
How does userspace know it's a failover
config and find the failover device right now?

> netvsc does this.
> Does this help with the init scripts and network manager to skip slave
> devices for dhcp requests?

Try it?