mlxsw: spectrum_router: Take router lock from inetaddr listeners

Another entry point into the routing code is from inetaddr listeners.
The driver registers listeners to IPv4 and IPv6 inetaddr notification
chains in order to understand when a RIF needs to be created or
destroyed.

Serialize access to shared router structures from these listeners by
taking the router lock when processing inetaddr events.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -7029,15 +7029,17 @@ static int mlxsw_sp_inetaddr_event(struct notifier_block *nb,
 
 	/* NETDEV_UP event is handled by mlxsw_sp_inetaddr_valid_event */
 	if (event == NETDEV_UP)
-		goto out;
+		return NOTIFY_DONE;
 
 	router = container_of(nb, struct mlxsw_sp_router, inetaddr_nb);
+	mutex_lock(&router->lock);
 	rif = mlxsw_sp_rif_find_by_dev(router->mlxsw_sp, dev);
 	if (!mlxsw_sp_rif_should_config(rif, dev, event))
 		goto out;
 
 	err = __mlxsw_sp_inetaddr_event(router->mlxsw_sp, dev, event, NULL);
 out:
+	mutex_unlock(&router->lock);
 	return notifier_from_errno(err);
 }
 
@@ -7052,8 +7054,9 @@ int mlxsw_sp_inetaddr_valid_event(struct notifier_block *unused,
 
 	mlxsw_sp = mlxsw_sp_lower_get(dev);
 	if (!mlxsw_sp)
-		goto out;
+		return NOTIFY_DONE;
 
+	mutex_lock(&mlxsw_sp->router->lock);
 	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
 	if (!mlxsw_sp_rif_should_config(rif, dev, event))
 		goto out;
@@ -7065,6 +7068,7 @@ int mlxsw_sp_inetaddr_valid_event(struct notifier_block *unused,
 
 	err = __mlxsw_sp_inetaddr_event(mlxsw_sp, dev, event, ivi->extack);
 out:
+	mutex_unlock(&mlxsw_sp->router->lock);
 	return notifier_from_errno(err);
 }
 
@@ -7138,8 +7142,9 @@ int mlxsw_sp_inet6addr_valid_event(struct notifier_block *unused,
 
 	mlxsw_sp = mlxsw_sp_lower_get(dev);
 	if (!mlxsw_sp)
-		goto out;
+		return NOTIFY_DONE;
 
+	mutex_lock(&mlxsw_sp->router->lock);
 	rif = mlxsw_sp_rif_find_by_dev(mlxsw_sp, dev);
 	if (!mlxsw_sp_rif_should_config(rif, dev, event))
 		goto out;
@@ -7151,6 +7156,7 @@ int mlxsw_sp_inet6addr_valid_event(struct notifier_block *unused,
 
 	err = __mlxsw_sp_inetaddr_event(mlxsw_sp, dev, event, i6vi->extack);
 out:
+	mutex_unlock(&mlxsw_sp->router->lock);
 	return notifier_from_errno(err);
 }