Re: [PATCH V5 mlx5-next 01/16] net/core: Introduce netdev_get_xmit_slave

[David Ahern <dsahern@gmail.com>]

On 4/23/20 6:55 AM, Maor Gottlieb wrote:
> Add new ndo to get the xmit slave of master device.
> Caller should call dev_put() when it no longer works with
> slave netdevice.

description needs to be updated.

> User can ask to get the xmit slave assume all the slaves can
> transmit by set all_slaves arg to true.
> 
> Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
> ---
>  include/linux/netdevice.h |  6 ++++++
>  net/core/dev.c            | 22 ++++++++++++++++++++++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 130a668049ab..d1206f08e099 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1389,6 +1389,9 @@ struct net_device_ops {
>  						 struct netlink_ext_ack *extack);
>  	int			(*ndo_del_slave)(struct net_device *dev,
>  						 struct net_device *slave_dev);
> +	struct net_device*	(*ndo_get_xmit_slave)(struct net_device *dev,
> +						      struct sk_buff *skb,
> +						      bool all_slaves);

documentation above struct net_device_ops { }; needs to be updated.

>  	netdev_features_t	(*ndo_fix_features)(struct net_device *dev,
>  						    netdev_features_t features);
>  	int			(*ndo_set_features)(struct net_device *dev,
> @@ -2731,6 +2734,9 @@ void netdev_freemem(struct net_device *dev);
>  void synchronize_net(void);
>  int init_dummy_netdev(struct net_device *dev);
>  
> +struct net_device *netdev_get_xmit_slave(struct net_device *dev,
> +					 struct sk_buff *skb,
> +					 bool all_slaves);
>  struct net_device *dev_get_by_index(struct net *net, int ifindex);
>  struct net_device *__dev_get_by_index(struct net *net, int ifindex);
>  struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex);
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 9c9e763bfe0e..e6c10980abfd 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -7785,6 +7785,28 @@ void netdev_bonding_info_change(struct net_device *dev,
>  }
>  EXPORT_SYMBOL(netdev_bonding_info_change);
>  
> +/**
> + * netdev_get_xmit_slave - Get the xmit slave of master device
> + * @skb: The packet
> + * @all_slaves: assume all the slaves are active
> + *
> + * The reference counters are not incremented so the caller must be
> + * careful with locks. The caller must hold RCU lock.
> + * %NULL is returned if no slave is found.
> + */
> +
> +struct net_device *netdev_get_xmit_slave(struct net_device *dev,
> +					 struct sk_buff *skb,
> +					 bool all_slaves)
> +{
> +	const struct net_device_ops *ops = dev->netdev_ops;
> +
> +	if (!ops->ndo_get_xmit_slave)
> +		return NULL;
> +	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
> +}
> +EXPORT_SYMBOL(netdev_get_xmit_slave);
> +
>  static void netdev_adjacent_add_links(struct net_device *dev)
>  {
>  	struct netdev_adjacent *iter;
>