[BRIDGE]: Fix deadlock in br_stp_disable_bridge

Looks like somebody forgot to use the _bh spin_lock variant. We ran into a
deadlock where br->hello_timer expired while br_stp_disable_br() walked
br->port_list.

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

diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index cc047f7..35cf3a0 100644 (file)
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -67,7 +67,7 @@ void br_stp_disable_bridge(struct net_bridge *br)
 {
        struct net_bridge_port *p;
 
-       spin_lock(&br->lock);
+       spin_lock_bh(&br->lock);
        list_for_each_entry(p, &br->port_list, list) {
                if (p->state != BR_STATE_DISABLED)
                        br_stp_disable_port(p);
@@ -76,7 +76,7 @@ void br_stp_disable_bridge(struct net_bridge *br)
 
        br->topology_change = 0;
        br->topology_change_detected = 0;
-       spin_unlock(&br->lock);
+       spin_unlock_bh(&br->lock);
 
        del_timer_sync(&br->hello_timer);
        del_timer_sync(&br->topology_change_timer);