datapath: Enforce mutual exclusion between bridge and brcompat_mod.

[sliver-openvswitch.git] / datapath / vport-netdev.c

diff --git a/datapath/vport-netdev.c b/datapath/vport-netdev.c
index 07c7abd..4cca7fe 100644 (file)
--- a/datapath/vport-netdev.c
+++ b/datapath/vport-netdev.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007-2011 Nicira Networks.
+ * Copyright (c) 2007-2012 Nicira Networks.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
@@ -420,19 +420,10 @@ const struct vport_ops ovs_netdev_vport_ops = {
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
 /*
- * In kernels earlier than 2.6.36, Open vSwitch cannot safely coexist with
- * the Linux bridge module on any released version of Linux, because there
- * is only a single bridge hook function and only a single br_port member
- * in struct net_device.
- *
- * Declaring and exporting this symbol enforces mutual exclusion.  The bridge
- * module also exports the same symbol, so the module loader will refuse to
- * load both modules at the same time (e.g. "bridge: exports duplicate symbol
- * br_should_route_hook (owned by openvswitch_mod)").
- *
- * The use of "typeof" here avoids the need to track changes in the type of
- * br_should_route_hook over various kernel versions.
+ * In kernels earlier than 2.6.36, Open vSwitch cannot safely coexist with the
+ * Linux bridge module, because there is only a single bridge hook function and
+ * only a single br_port member in struct net_device, so this prevents loading
+ * both bridge and openvswitch_mod at the same time.
  */
-typeof(br_should_route_hook) br_should_route_hook;
-EXPORT_SYMBOL(br_should_route_hook);
+BRIDGE_MUTUAL_EXCLUSION;
 #endif