Merge branch 'net-support-binding-vlan-dev-link-state-to-vlan-member-bridge-ports'

Mike Manning says:

====================
net: support binding vlan dev link state to vlan member bridge ports

For vlan filtering on bridges, the bridge may also have vlan devices
as upper devices. For switches, these are used to provide L3 packet
processing for ports that are members of a given vlan.

While it is correct that the admin state for these vlan devices is
either set directly for the device or inherited from the lower device,
the link state is also transferred from the lower device. So this is
always up if the bridge is in admin up state and there is at least one
bridge port that is up, regardless of the vlan that the port is in.

The link state of the vlan device may need to track only the state of
the subset of ports that are also members of the corresponding vlan,
rather than that of all ports.

This series provides an optional vlan flag so that the link state of
the vlan device is only up if there is at least one bridge port that is
up AND is a member of the corresponding vlan.

v2:
   - Address review comments from Nikolay Aleksandrov
     in patches 3 & 4 and add patch 5 to address bridge link down due to STP
v3:
   - Address review comment from Nikolay Aleksandrov
     in patch 4 so as to remove unnecessary inline #ifdef
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 8 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 8d77b6ee4477..f044ae56a313 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -223,7 +223,8 @@ int vlan_dev_change_flags(const struct net_device *dev, u32 flags, u32 mask)
         u32 old_flags = vlan->flags;
 
         if (mask & ~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP |
-                     VLAN_FLAG_LOOSE_BINDING | VLAN_FLAG_MVRP))
+                     VLAN_FLAG_LOOSE_BINDING | VLAN_FLAG_MVRP |
+                     VLAN_FLAG_BRIDGE_BINDING))
                 return -EINVAL;
 
         vlan->flags = (old_flags & ~mask) | (flags & mask);
@@ -296,7 +297,8 @@ static int vlan_dev_open(struct net_device *dev)
         if (vlan->flags & VLAN_FLAG_MVRP)
                 vlan_mvrp_request_join(dev);
 
-        if (netif_carrier_ok(real_dev))
+        if (netif_carrier_ok(real_dev) &&
+            !(vlan->flags & VLAN_FLAG_BRIDGE_BINDING))
                 netif_carrier_on(dev);
         return 0;
 
@@ -326,7 +328,8 @@ static int vlan_dev_stop(struct net_device *dev)
         if (!ether_addr_equal(dev->dev_addr, real_dev->dev_addr))
                 dev_uc_del(real_dev, dev->dev_addr);
 
-        netif_carrier_off(dev);
+        if (!(vlan->flags & VLAN_FLAG_BRIDGE_BINDING))
+                netif_carrier_off(dev);
         return 0;
 }
 
@@ -550,7 +553,8 @@ static const struct net_device_ops vlan_netdev_ops;
 
 static int vlan_dev_init(struct net_device *dev)
 {
-        struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
+        struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
+        struct net_device *real_dev = vlan->real_dev;
 
         netif_carrier_off(dev);
 
@@ -561,6 +565,9 @@ static int vlan_dev_init(struct net_device *dev)
                                           (1<<__LINK_STATE_DORMANT))) |
                       (1<<__LINK_STATE_PRESENT);
 
+        if (vlan->flags & VLAN_FLAG_BRIDGE_BINDING)
+                dev->state |= (1 << __LINK_STATE_NOCARRIER);
+
         dev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG |
                            NETIF_F_FRAGLIST | NETIF_F_GSO_SOFTWARE |
                            NETIF_F_GSO_ENCAP_ALL |
@@ -591,8 +598,7 @@ static int vlan_dev_init(struct net_device *dev)
 #endif
 
         dev->needed_headroom = real_dev->needed_headroom;
-        if (vlan_hw_offload_capable(real_dev->features,
-                                    vlan_dev_priv(dev)->vlan_proto)) {
+        if (vlan_hw_offload_capable(real_dev->features, vlan->vlan_proto)) {
                 dev->header_ops      = &vlan_passthru_header_ops;
                 dev->hard_header_len = real_dev->hard_header_len;
         } else {
@@ -606,8 +612,8 @@ static int vlan_dev_init(struct net_device *dev)
 
         vlan_dev_set_lockdep_class(dev, vlan_dev_get_lock_subclass(dev));
 
-        vlan_dev_priv(dev)->vlan_pcpu_stats = netdev_alloc_pcpu_stats(struct vlan_pcpu_stats);
-        if (!vlan_dev_priv(dev)->vlan_pcpu_stats)
+        vlan->vlan_pcpu_stats = netdev_alloc_pcpu_stats(struct vlan_pcpu_stats);
+        if (!vlan->vlan_pcpu_stats)
                 return -ENOMEM;
 
         return 0;