Message ID | 20240212191844.1055186-3-tobias@waldekranz.com (mailing list archive) |
---|---|
State | Superseded |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | net: bridge: switchdev: Ensure MDB events are delivered exactly once | expand |
On Mon, Feb 12, 2024 at 08:18:44PM +0100, Tobias Waldekranz wrote: > When unoffloading a device, it is important to ensure that all > relevant deferred events are delivered to it before it disassociates > itself from the bridge. > > Before this change, this was true for the normal case when a device > maps 1:1 to a net_bridge_port, i.e. > > br0 > / > swp0 > > When swp0 leaves br0, the call to switchdev_deferred_process() in > del_nbp() makes sure to process any outstanding events while the > device is still associated with the bridge. > > In the case when the association is indirect though, i.e. when the > device is attached to the bridge via an intermediate device, like a > LAG... > > br0 > / > lag0 > / > swp0 > > ...then detaching swp0 from lag0 does not cause any net_bridge_port to > be deleted, so there was no guarantee that all events had been > processed before the device disassociated itself from the bridge. > > Fix this by always synchronously processing all deferred events before > signaling completion of unoffloading back to the driver. > > Fixes: 4e51bf44a03a ("net: bridge: move the switchdev object replay helpers to "push" mode") > Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> > --- Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c index 6a7cb01f121c..7b41ee8740cb 100644 --- a/net/bridge/br_switchdev.c +++ b/net/bridge/br_switchdev.c @@ -804,6 +804,16 @@ static void nbp_switchdev_unsync_objs(struct net_bridge_port *p, br_switchdev_mdb_replay(br_dev, dev, ctx, false, blocking_nb, NULL); br_switchdev_vlan_replay(br_dev, ctx, false, blocking_nb, NULL); + + /* Make sure that the device leaving this bridge has seen all + * relevant events before it is disassociated. In the normal + * case, when the device is directly attached to the bridge, + * this is covered by del_nbp(). If the association was indirect + * however, e.g. via a team or bond, and the device is leaving + * that intermediate device, then the bridge port remains in + * place. + */ + switchdev_deferred_process(); } /* Let the bridge know that this port is offloaded, so that it can assign a
When unoffloading a device, it is important to ensure that all relevant deferred events are delivered to it before it disassociates itself from the bridge. Before this change, this was true for the normal case when a device maps 1:1 to a net_bridge_port, i.e. br0 / swp0 When swp0 leaves br0, the call to switchdev_deferred_process() in del_nbp() makes sure to process any outstanding events while the device is still associated with the bridge. In the case when the association is indirect though, i.e. when the device is attached to the bridge via an intermediate device, like a LAG... br0 / lag0 / swp0 ...then detaching swp0 from lag0 does not cause any net_bridge_port to be deleted, so there was no guarantee that all events had been processed before the device disassociated itself from the bridge. Fix this by always synchronously processing all deferred events before signaling completion of unoffloading back to the driver. Fixes: 4e51bf44a03a ("net: bridge: move the switchdev object replay helpers to "push" mode") Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> --- net/bridge/br_switchdev.c | 10 ++++++++++ 1 file changed, 10 insertions(+)