net: Resend IGMP memberships upon peer notification.

[ Upstream commit 37c343b4f4e70e9dc328ab04903c0ec8d154c1a4 ]

When we notify peers of potential changes,  it's also good to update
IGMP memberships.  For example, during VM migration, updating IGMP
memberships will redirect existing multicast streams to the VM at the
new location.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/core/dev.c b/net/core/dev.c
index 630704d8d6a2d0973e90b678157569c4a18ca80b..3b67c1e5756f99853630a55f9e819a7f49659ab1 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1300,6 +1300,7 @@ void netdev_notify_peers(struct net_device *dev)
 {
        rtnl_lock();
        call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
+       call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
        rtnl_unlock();
 }
 EXPORT_SYMBOL(netdev_notify_peers);