bridge: Use RCU list primitive in __br_mdb_ip_get

As Paul McKenney correctly pointed out, __br_mdb_ip_get needs
to use the RCU list walking primitive in order to work correctly
on platforms where data-dependency ordering is not guaranteed.

Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 8b25887..a1ffe15 100644 (file)
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -38,7 +38,7 @@ static struct net_bridge_mdb_entry *__br_mdb_ip_get(
        struct net_bridge_mdb_entry *mp;
        struct hlist_node *p;
 
-       hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
+       hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
                if (dst == mp->addr)
                        return mp;
        }