diff mbox series

[RFC,v2,net-next,01/16] net: dsa: call dsa_port_bridge_join when joining a LAG that is already in a bridge

Message ID 20210318231829.3892920-2-olteanv@gmail.com
State New
Headers show
Series Better support for sandwiched LAGs with bridge and DSA | expand

Commit Message

Vladimir Oltean March 18, 2021, 11:18 p.m. UTC 
From: Vladimir Oltean <vladimir.oltean@nxp.com>

DSA can properly detect and offload this sequence of operations:

ip link add br0 type bridge
ip link add bond0 type bond
ip link set swp0 master bond0
ip link set bond0 master br0

But not this one:

ip link add br0 type bridge
ip link add bond0 type bond
ip link set bond0 master br0
ip link set swp0 master bond0

Actually the second one is more complicated, due to the elapsed time
between the enslavement of bond0 and the offloading of it via swp0, a
lot of things could have happened to the bond0 bridge port in terms of
switchdev objects (host MDBs, VLANs, altered STP state etc). So this is
a bit of a can of worms, and making sure that the DSA port's state is in
sync with this already existing bridge port is handled in the next
patches.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 net/dsa/port.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

Comments

Tobias Waldekranz March 22, 2021, 10:24 a.m. UTC | #1 
On Fri, Mar 19, 2021 at 01:18, Vladimir Oltean <olteanv@gmail.com> wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>

>

> DSA can properly detect and offload this sequence of operations:

>

> ip link add br0 type bridge

> ip link add bond0 type bond

> ip link set swp0 master bond0

> ip link set bond0 master br0

>

> But not this one:

>

> ip link add br0 type bridge

> ip link add bond0 type bond

> ip link set bond0 master br0

> ip link set swp0 master bond0

>

> Actually the second one is more complicated, due to the elapsed time

> between the enslavement of bond0 and the offloading of it via swp0, a

> lot of things could have happened to the bond0 bridge port in terms of

> switchdev objects (host MDBs, VLANs, altered STP state etc). So this is

> a bit of a can of worms, and making sure that the DSA port's state is in

> sync with this already existing bridge port is handled in the next

> patches.

>

> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

> ---


Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
diff mbox series

Patch

diff --git a/net/dsa/port.c b/net/dsa/port.c
index c9c6d7ab3f47..d39262a9fe0e 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -249,17 +249,31 @@  int dsa_port_lag_join(struct dsa_port *dp, struct net_device *lag,
 		.lag = lag,
 		.info = uinfo,
 	};
+	struct net_device *bridge_dev;
 	int err;
 
 	dsa_lag_map(dp->ds->dst, lag);
 	dp->lag_dev = lag;
 
 	err = dsa_port_notify(dp, DSA_NOTIFIER_LAG_JOIN, &info);
-	if (err) {
-		dp->lag_dev = NULL;
-		dsa_lag_unmap(dp->ds->dst, lag);
-	}
+	if (err)
+		goto err_lag_join;
 
+	bridge_dev = netdev_master_upper_dev_get(lag);
+	if (!bridge_dev || !netif_is_bridge_master(bridge_dev))
+		return 0;
+
+	err = dsa_port_bridge_join(dp, bridge_dev);
+	if (err)
+		goto err_bridge_join;
+
+	return 0;
+
+err_bridge_join:
+	dsa_port_notify(dp, DSA_NOTIFIER_LAG_LEAVE, &info);
+err_lag_join:
+	dp->lag_dev = NULL;
+	dsa_lag_unmap(dp->ds->dst, lag);
 	return err;
 }