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 93e36e9102e96b850c65651d3c5946a8b40cecbd..cae21f769212617b8e03a3015205eb9b22871bb0 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1248,6 +1248,7 @@ 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);