| Message ID | 20140502165727.850ECE635B@unicorn.suse.cz |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 69aff72..34ca55d 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1038,6 +1038,7 @@ static void bond_compute_features(struct bonding *bond) if (!bond_has_slaves(bond)) goto done; + vlan_features &= NETIF_F_ALL_FOR_ALL; bond_for_each_slave(bond, slave, iter) { vlan_features = netdev_increment_features(vlan_features,
bond_compute_features() uses netdev_increment_features() to combine vlan_features of slaves into vlan_features of the bond. As netdev_increment_features() only adds most features and we start with BOND_VLAN_FEATURES, we may end up with features none of the slaves provided. In particular, BOND_VLAN_FEATURES contains NETIF_F_HW_CSUM so that netdev_increment_features() clears NETIF_F_IP{,V6}_CSUM and if we only have slaves with NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM (e.g. ixgbe based cards), the same will be in features of the bond and a vlan device on top of the bond would support no checksumming, resulting in significant performance degradation. If there is at least one slave, initialize vlan_features only with the flags in NETIF_F_ALL_FOR_ALL. Right now there is none in BOND_VLAN_FEATURES but stating it explicitely will make the code more future proof. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> --- drivers/net/bonding/bond_main.c | 1 + 1 file changed, 1 insertion(+)