Subject: Re: [PATCH net-next v3 2/5] swdevice: add new api to set and del bridge port attributes

From: roopa <[email-masked]>
Date: Fri, 23 Jan 2015 14:45:46 -0800

On 1/23/15, 8:06 AM, Jiri Pirko wrote:
> Fri, Jan 23, 2015 at 04:58:57PM CET, [email-masked] wrote:
>> On 1/23/15, 2:41 AM, Jiri Pirko wrote:
>>
>> <snip..>
>>> +
>>> +/**
>>> + *	netdev_switch_port_bridge_dellink - Notify switch device port of bridge
>>> + *	attribute delete
>>> + *
>>> + *	@dev: port device
>>> + *	@nlh: netlink msg with bridge port attributes
>>> + *
>>> + *	Notify switch device port of bridge port attribute delete
>>> + */
>>> +int netdev_switch_port_bridge_dellink(struct net_device *dev,
>>> +				      struct nlmsghdr *nlh, u16 flags)
>>> +{
>>> +	const struct net_device_ops *ops = dev->netdev_ops;
>>> +	struct net_device *lower_dev;
>>> +	struct list_head *iter;
>>> +	int ret = 0, err = 0;
>>> +
>>> +	if (!(dev->features & NETIF_F_HW_NETFUNC_OFFLOAD))
>>> +		return err;
>>> +
>>> +	if (ops->ndo_bridge_dellink) {
>>> +		WARN_ON(!ops->ndo_switch_parent_id_get);
>>> +		return ops->ndo_bridge_dellink(dev, nlh, flags);
>>> +	}
>>> +
>>> +	netdev_for_each_lower_dev(dev, lower_dev, iter) {
>>> +		err = netdev_switch_port_bridge_dellink(lower_dev, nlh, flags);
>>> +		if (err)
>>> +			ret = err;
>>> +	}
>>> +
>>> +	return ret;
>>> +}
>>> +EXPORT_SYMBOL(netdev_switch_port_bridge_dellink);
>>> -- 
>>> 1.7.10.4
>>>
>>> Is there any other place, other than bridge code, this functions are
>>> suppored to be called from?
>> No other place today. Its usually the master that implements
>> ndo_bridge_setlink/dellink.
>>
>>> If not, which I consider likely, it would
>>> make more sense to me to:
>>>
>>> - move netdev_for_each_lower_dev iterations directly to bridge code
>>> - let the masters (bond, team, ..) implement ndo_bridge_*link and do
>>>    the traversing there (can be in a form of pre-prepared default
>>>    ndo callback (ndo_dflt_netdev_switch_port_bridge_*link)
>> But, i am still not understanding why i would modify bond, team and other
>> slaves
> Well, that is the usual way to propagate ndo calls. People are used to
> this. It is visible right away in bonding/other code that is propagated
> some ndo call to slaves. With your code, that is somehow hidden and only
> dependent on NETIF_F_HW_NETFUNC_OFFLOAD flag.
>
> Note that there are only couple of "master drivers" (for this, most likely
> only bond and team modifications are needed).
>   
ndo_bridge_setlink today is only implemented by drivers that implement 
bridging function.
So, having the bond and team driver implement it...seems odd.

But if you insist, i am going to do just that.