bridge: update sysfs link names if port device names have changed

Links for each port are created in sysfs using the device
name, but this could be changed after being added to the
bridge.

As well as being unable to remove interfaces after this
occurs (because userspace tools don't recognise the new
name, and the kernel won't recognise the old name), adding
another interface with the old name to the bridge will
cause an error trying to create the sysfs link.

This fixes the problem by listening for NETDEV_CHANGENAME
notifications and renaming the link.

https://bugzilla.kernel.org/show_bug.cgi?id=12743

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 1413b72acc7f..717e1fd6133c 100644
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -34,6 +34,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
         struct net_device *dev = ptr;
         struct net_bridge_port *p = dev->br_port;
         struct net_bridge *br;
+        int err;
 
         /* not a port of a bridge */
         if (p == NULL)
@@ -83,6 +84,12 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
                 br_del_if(br, dev);
                 break;
 
+        case NETDEV_CHANGENAME:
+                err = br_sysfs_renameif(p);
+                if (err)
+                        return notifier_from_errno(err);
+                break;
+
         case NETDEV_PRE_TYPE_CHANGE:
                 /* Forbid underlaying device to change its type. */
                 return NOTIFY_BAD;