Re: [patch net-next] bonding: create netlink event when bonding option is changed

[Veaceslav Falico <vfalico@gmail.com>]

On Wed, Aug 20, 2014 at 08:44:58AM +0200, Jiri Pirko wrote:
>Tue, Aug 19, 2014 at 10:46:34PM CEST, gospo@cumulusnetworks.com wrote:
>>On Tue, Aug 19, 2014 at 10:37:48PM +0200, Jiri Pirko wrote:
>>> Tue, Aug 19, 2014 at 10:34:01PM CEST, gospo@cumulusnetworks.com wrote:
>>> >On Tue, Aug 19, 2014 at 04:02:12PM +0200, Jiri Pirko wrote:
...snip...
>>> >>  	if (ret)
>>> >>  		bond_opt_error_interpret(bond, opt, ret, val);
>>> >> +	else
>>> >> +		call_netdevice_notifiers(NETDEV_CHANGEINFODATA, bond->dev);
...snip...
>>My question was:  Is there a need for 2 netlink messages to indicate
>>that a bonding configuration change was needed when the config came over
>>netlink.  I did not see the need for 2 netlink messages in this case and
>>was asking for clarification from you.
>
>Imagine 2 applications. One is just monitoring netlink events ("ip
>mon"), the second is setting up bond via netlink. Now, the second sends
>a message to kernel, that is unicast to kernel. The first application
>does not see that message. Therefore there is need to generate the event
>message in kernel and send it back to userspace via multicast.
>That message the first application will see. And that is exactly what
>my patch is doing.

Seems fair, as there's no other way to catch those modifications, even
though they're known to the "changing" application.

Acked-by: Veaceslav Falico <vfalico@gmail.com>