[BRIDGE]: fix race on bridge del if

This fixes the RCU race on bridge delete interface.  Basically,
the network device has to be detached from the bridge in the first
step (pre-RCU), rather than later. At that point, no more bridge traffic
will come in, and the other code will not think that network device
is part of a bridge.

This should also fix the XEN test problems.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 91bb895375f4c8e90c4ef6190e19dd7de4de6c0f..defcf6a8607c3714f54dbb225b471570837dc630 100644 (file)
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -79,7 +79,6 @@ static void destroy_nbp(struct net_bridge_port *p)
 {
        struct net_device *dev = p->dev;
 
-       dev->br_port = NULL;
        p->br = NULL;
        p->dev = NULL;
        dev_put(dev);
@@ -100,6 +99,7 @@ static void del_nbp(struct net_bridge_port *p)
        struct net_bridge *br = p->br;
        struct net_device *dev = p->dev;
 
+       dev->br_port = NULL;
        dev_set_promiscuity(dev, -1);
 
        spin_lock_bh(&br->lock);