[PATCH net-next v2 5/5] bridge: update vlan dev link state for bridge netdev changes

[Mike Manning <mmanning@vyatta.att-mail.com>]

If vlan bridge binding is enabled, then the link state of a vlan device
that is an upper device of the bridge tracks the state of bridge ports
that are members of that vlan. But this can only be done when the link
state of the bridge is up. If it is down, then the link state of the
vlan devices must also be down. This is to maintain existing behavior
for when STP is enabled and there are no live ports, in which case the
link state for the bridge and any vlan devices is down.

Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
---
 net/bridge/br_vlan.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 89146a5f0c23..2db63997f313 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1343,6 +1343,11 @@ static void br_vlan_set_vlan_dev_state(const struct net_bridge *br,
 	struct net_bridge_port *p;
 	bool has_carrier = false;
 
+	if (!netif_carrier_ok(br->dev)) {
+		netif_carrier_off(vlan_dev);
+		return;
+	}
+
 	list_for_each_entry(p, &br->port_list, list) {
 		vg = nbp_vlan_group(p);
 		if (br_vlan_find(vg, vid) && br_vlan_is_dev_up(p->dev)) {
@@ -1367,10 +1372,12 @@ static void br_vlan_set_all_vlan_dev_state(struct net_bridge_port *p)
 		vlan_dev = br_vlan_get_upper_bind_vlan_dev(p->br->dev,
 							   vlan->vid);
 		if (vlan_dev) {
-			if (br_vlan_is_dev_up(p->dev))
-				netif_carrier_on(vlan_dev);
-			else
+			if (br_vlan_is_dev_up(p->dev)) {
+				if (netif_carrier_ok(p->br->dev))
+					netif_carrier_on(vlan_dev);
+			} else {
 				br_vlan_set_vlan_dev_state(p->br, vlan_dev);
+			}
 		}
 	}
 }
@@ -1393,6 +1400,34 @@ static void br_vlan_upper_change(struct net_device *dev,
 	}
 }
 
+struct br_vlan_link_state_walk_data {
+	struct net_bridge *br;
+};
+
+static int br_vlan_link_state_change_fn(struct net_device *vlan_dev,
+					void *data_in)
+{
+	struct br_vlan_link_state_walk_data *data = data_in;
+
+	if (br_vlan_is_bind_vlan_dev(vlan_dev))
+		br_vlan_set_vlan_dev_state(data->br, vlan_dev);
+
+	return 0;
+}
+
+static void br_vlan_link_state_change(struct net_device *dev,
+				      struct net_bridge *br)
+{
+	struct br_vlan_link_state_walk_data data = {
+		.br = br
+	};
+
+	rcu_read_lock();
+	netdev_walk_all_upper_dev_rcu(dev, br_vlan_link_state_change_fn,
+				      &data);
+	rcu_read_unlock();
+}
+
 /* Must be protected by RTNL. */
 static void nbp_vlan_set_vlan_dev_state(struct net_bridge_port *p, u16 vid)
 {
@@ -1411,12 +1446,21 @@ void br_vlan_bridge_event(struct net_device *dev, unsigned long event,
 			  void *ptr)
 {
 	struct netdev_notifier_changeupper_info *info;
+	struct net_bridge *br;
 
 	switch (event) {
 	case NETDEV_CHANGEUPPER:
 		info = ptr;
 		br_vlan_upper_change(dev, info->upper_dev, info->linking);
 		break;
+
+	case NETDEV_CHANGE:
+	case NETDEV_UP:
+		br = netdev_priv(dev);
+		if (!br_opt_get(br, BROPT_VLAN_BRIDGE_BINDING))
+			return;
+		br_vlan_link_state_change(dev, br);
+		break;
 	}
 }
 
-- 
2.11.0