RE: [PATCH v3 1/4] net: add name_assign_type netdev attribute

[David Laight <David.Laight@ACULAB.COM>]

From: David Herrmann
> The name_assign_type attribute gives hints where the interface name of a
> given net-device comes from. Three different values are currently defined:
>   NET_NAME_ENUM:
>     This is the default. The ifname is provided by the kernel with an
>     enumerated suffix. Names may be reused and unstable.
>   NET_NAME_USER:
>     The ifname was provided by user-space during net-device setup.
>   NET_NAME_RENAMED:
>     The net-device has been renamed via RTNL. Once this type is set, it
>     cannot change again.
...
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index b8d8c80..6698e87 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1248,6 +1248,7 @@ struct net_device {
>  	 * of the interface.
>  	 */
>  	char			name[IFNAMSIZ];
> +	unsigned char		name_assign_type; /* name assignment type */
> 
>  	/* device name hash chain, please keep it close to name[] */
>  	struct hlist_node	name_hlist;

Do you really need to add 7 byte of padding here?
There seems to be some padding lurking elsewhere that really ought
to be mergable.

	David