On Tue, 13 May 2014 17:16:11 +0200 Jiri Pirko <[email protected]> wrote:
> Tue, May 13, 2014 at 09:55:08AM CEST, [email protected] wrote: > >From: Jon Maxwell <[email protected]> > > > >There has been a number incidents recently where customers running KVM have > >reported that VM hosts on different Hypervisors are unreachable. Based on > >pcap traces we found that the bridge was broadcasting the ARP request out > >onto the network. However some NICs have an inbuilt switch which on > >occasions > >were broadcasting the VMs ARP request back through the physical NIC on the > >Hypervisor. This resulted in the bridge changing ports and incorrectly > >learning > >that the VMs mac address was external. As a result the ARP reply was > >directed > >back onto the external network and VM never updated it's ARP cache. This > >patch > >will notify the bridge command to identify such port toggling. > > > >Signed-off-by: Jon Maxwell <[email protected]> > >--- > > net/bridge/br_fdb.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > >diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c > >index 9203d5a..37742e2 100644 > >--- a/net/bridge/br_fdb.c > >+++ b/net/bridge/br_fdb.c > >@@ -507,6 +507,8 @@ void br_fdb_update(struct net_bridge *br, struct > >net_bridge_port *source, > > source->dev->name); > > } else { > > /* fastpath: update of existing entry */ > >+ if (source->port_no != fdb->dst->port_no) > >+ fdb_notify(br, fdb, RTM_NEWNEIGH); > > fdb->dst = source; > > fdb->updated = jiffies; > > if (unlikely(added_by_user)) > >-- > >1.8.3.1 > > > Reviewed-by: Jiri Pirko <[email protected]> I like the patch, but please add unlikely() to this conditional. This is in the fast path code for bridge learning. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
