4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Julian Wiedmann jwi@linux.vnet.ibm.com
[ Upsteam commit bc3ab70584696cb798b9e1e0ac8e6ced5fd4c3b8 ]
Commit 5f78e29ceebf ("qeth: optimize IP handling in rx_mode callback") reworked how secondary addresses are managed for qeth devices. Instead of dropping & subsequently re-adding all addresses on every ndo_set_rx_mode() call, qeth now keeps track of the addresses that are currently registered with the HW. On a ndo_set_rx_mode(), we thus only need to do (de-)registration requests for the addresses that have actually changed.
On L3 devices, the lookup for IPv4 Multicast addresses checks the wrong hashtable - and thus never finds a match. As a result, we first delete *all* such addresses, and then re-add them again. So each set_rx_mode() causes a short period where the IPv4 Multicast addresses are not registered, and the card stops forwarding inbound traffic for them.
Fix this by setting the ->is_multicast flag on the lookup object, thus enabling qeth_l3_ip_from_hash() to search the correct hashtable and find a match there.
Fixes: 5f78e29ceebf ("qeth: optimize IP handling in rx_mode callback") Signed-off-by: Julian Wiedmann jwi@linux.vnet.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/net/qeth_l3_main.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -1416,6 +1416,7 @@ qeth_l3_add_mc_to_hash(struct qeth_card
tmp->u.a4.addr = im4->multiaddr; memcpy(tmp->mac, buf, sizeof(tmp->mac)); + tmp->is_multicast = 1;
ipm = qeth_l3_ip_from_hash(card, tmp); if (ipm) {