Re: [PATCH net-2.6] bonding: Bonding driver does not consider the gso_max_size setting of slaves.

[Neil Horman <nhorman@tuxdriver.com>]

On Wed, Nov 21, 2012 at 04:48:56PM +0530, sarveshwar.bandi@emulex.com wrote:
> From: Sarveshwar Bandi <sarveshwar.bandi@emulex.com>
> 
> Patch sets the lowest non-zero gso_max_size value of the slaves during enslave
> and detach.
> 
> Signed-off-by: Sarveshwar Bandi <sarveshwar.bandi@emulex.com>
> ---
>  drivers/net/bonding/bond_main.c |   27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index b2530b0..5f19d16 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -1198,6 +1198,31 @@ static void bond_attach_slave(struct bonding *bond, struct slave *new_slave)
>  	bond->slave_cnt++;
>  }
>  
> +static void bond_set_gso_max_size(struct bonding *bond)
> +{
> +	struct slave *slave;
> +	struct net_device *bond_dev = bond->dev;
> +	unsigned int gso_max_size = 0;
> +	bool reset_gso_size = true;
> +	int i;
> +
> +	bond_for_each_slave(bond, slave, i) {
> +		if (!slave->dev->gso_max_size)
> +			continue;
> +
> +		reset_gso_size = false;
> +
> +		if (!gso_max_size ||
> +		    slave->dev->gso_max_size < gso_max_size)
> +			gso_max_size = slave->dev->gso_max_size;
> +	}
> +
> +	if (gso_max_size && gso_max_size < bond_dev->gso_max_size)
> +		netif_set_gso_max_size(bond_dev, gso_max_size);
> +	else if (reset_gso_size)
> +		netif_set_gso_max_size(bond_dev, 0);
> +}
> +
This seems a bit overly complex.  It doesn't seem like you need the
reset_go_size bool in here at all.  Just initalize gso_max_size to GSO_MAX_SIZE
and reduce it every time you find a smaller gso value on a slave.  Then you can
unilaterally set the bond devices gso_max_size without having to check any bools
or do any comparisons.

Regards
Neil