On Wed, Mar 1, 2017 at 8:11 AM, Brad Campbell <lists2...@fnarfbargle.com> wrote:
> G'day Jarod,
>
> I have a pair of machines that are linked by a pair of quad port e1000 cards
> with all 4 ports bonded. The network is configured with an mtu of 9000.
>
> Kernel 4.10 fails to bring these interfaces up as it fails when trying to
> set the mtu on the bond interface higher than 1500. A bisect between 4.9 &
> 4.10 winds up identifying this commit as where it all goes wrong. If I
> modify the network config to not touch the mtu (ie leave it at 1500) then it
> comes up ok.
>
> I can individually configure each port with an mtu of 9000, so the e1000
> driver is ok, but there appears to be breakage in the bonding driver related
> to your mtu api changes.
>
> I've just reverted to an older kernel, so it's no biggie. And as it's still
> a problem in the latest git head I assume nobody else has encountered it. I
> thought it worth reporting in case it triggers a quick lightbulb.
I think we need the following patch:
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 6321f12..de47006 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4179,6 +4179,7 @@ void bond_setup(struct net_device *bond_dev)
/* Initialize the device entry points */
ether_setup(bond_dev);
+ dev->max_mtu = ETH_MAX_MTU;
bond_dev->netdev_ops = &bond_netdev_ops;
bond_dev->ethtool_ops = &bond_ethtool_ops;
