Subject: Re: [ofa-general] Re: [PATCH V4 8/10] net/bonding: Handlle wrong assumptions that slave is always an Ethernet device

From: Moni Shoua <[email-masked]>
Date: Wed, 29 Aug 2007 16:37:34 +0300

Jay Vosburgh wrote:
> Moni Shoua <[email-masked]> wrote:
> 
>> bonding sometimes uses Ethernet constants (such as MTU and address length) which
>> are not good when it enslaves non Ethernet devices (such as InfiniBand).
>>
>> Signed-off-by: Moni Shoua <[email-masked]>
>> ---
>> drivers/net/bonding/bond_main.c  |    3 ++-
>> drivers/net/bonding/bond_sysfs.c |   19 +++++++++++++------
>> drivers/net/bonding/bonding.h    |    1 +
>> 3 files changed, 16 insertions(+), 7 deletions(-)
>>
>> Index: net-2.6/drivers/net/bonding/bond_main.c
>> ===================================================================
>> --- net-2.6.orig/drivers/net/bonding/bond_main.c	2007-08-15 10:55:48.000000000 +0300
>> +++ net-2.6/drivers/net/bonding/bond_main.c	2007-08-20 14:29:11.911298577 +0300
>> @@ -1224,7 +1224,8 @@ static int bond_compute_features(struct 
>> 	struct slave *slave;
>> 	struct net_device *bond_dev = bond->dev;
>> 	unsigned long features = bond_dev->features;
>> -	unsigned short max_hard_header_len = ETH_HLEN;
>> +	unsigned short max_hard_header_len = max((u16)ETH_HLEN,
>> +						bond_dev->hard_header_len);
> 
> 	Since non-IB bonding masters are run through ether_setup, which
> sets hard_header_len to ETH_HLEN, the max() is probably unnecessary, and
> I think this could just be bond_dev->hard_header_len.
> 
This is true except for the case where there are no slaves left.
In that case max_hard_header_len has equals to the initialization value.

       bond_for_each_slave(bond, slave, i) {
                features = netdev_compute_features(features,
                                                   slave->dev->features);
                if (slave->dev->hard_header_len > max_hard_header_len)
                        max_hard_header_len = slave->dev->hard_header_len;
        }

        features |= (bond_dev->features & BOND_VLAN_FEATURES);
        bond_dev->features = features;
        bond_dev->hard_header_len = max_hard_header_len;