From: jbeulich@novell.com
Subject: Module use count must be updated as bridges are created/destroyed
Patch-mainline: unknown
References: 267651

Otherwise 'modprobe -r' on a module having a dependency on bridge will
implicitly unload bridge, bringing down all connectivity that was using
bridges.

---
 net/bridge/br_if.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -239,12 +239,19 @@ int br_add_bridge(struct net *net, const
 	if (!dev)
 		return -ENOMEM;
 
+	if (!try_module_get(THIS_MODULE)) {
+		free_netdev(dev);
+		return -ENOENT;
+	}
+
 	dev_net_set(dev, net);
 	dev->rtnl_link_ops = &br_link_ops;
 
 	res = register_netdev(dev);
-	if (res)
+	if (res) {
 		free_netdev(dev);
+		module_put(THIS_MODULE);
+	}
 	return res;
 }
 
@@ -272,6 +279,8 @@ int br_del_bridge(struct net *net, const
 		br_dev_delete(dev, NULL);
 
 	rtnl_unlock();
+	if (ret == 0)
+		module_put(THIS_MODULE);
 	return ret;
 }