On Wed, 21 Sep 2022 07:45:07 +0300 Nikolay Aleksandrov wrote:

quoted

IDK, vlan knows it's calling the bridge:

+	if ((vlan->flags ^ old_flags) & VLAN_FLAG_BRIDGE_BINDING &&
+	    netif_is_bridge_master(vlan->real_dev)) {

This one is more of an optimization so notifications are sent only when the bridge
is involved, it can be removed if other interested parties show up.

quoted

bridge knows it's vlan calling:

+	if (is_vlan_dev(dev)) {
+		br_vlan_device_event(dev, event, ptr);

going thru the generic NETDEV notifier seems odd.

If this is just to avoid the dependency we can perhaps add a stub 
like net/ipv4/udp_tunnel_stub.c ?

I suggested the notifier to be more generic and be able to re-use it for other link types although
I don't have other use cases in mind right now. Stubs are an alternative as long as they and
their lifetime are properly managed. I don't have a strong preference here so if you prefer
stubs I'm good.

Yup, stub seems simpler and more efficient to me. Only time will
tell if indeed this ntf type would have been reused further.. 🤷