Re: [PATCH 5/5 v2] net: add old_queue_mapping into skb->cb

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mercredi 15 décembre 2010 à 13:23 +0800, Changli Gao a écrit :
> For the skbs returned from ifb, we should use the queue_mapping
> saved before ifb.
> 
> We save old queue_mapping in old_queue_mapping just before calling 
> dev_queue_xmit, and restore the old_queue_mapping to queue_mapping
> just before reinjecting the skb.
> 
> dev_pick_tx() use the current queue_mapping for the skbs reinjected
> by ifb.
> 
> A new struct dev_skb_cb is added, and valid in qdisc and gso layer.
> The original qdisc_skb_cb and DEV_GSO_CB are placed after dev_skb_cb.
> 
> Signed-off-by: Changli Gao <xiaosuo@gmail.com>

This is really ugly and error prone.

Could you just use a more normal way to express this ?


struct ifb_save_fields_cb {
	u16 queue_mapping;
};

struct napi_gro_cb {
	struct ifb_save_fields_cb ifb_cb; /* needed by ifb, must be first */
	...
}


struct qdisc_skb_cb {
	struct ifb_save_fields_cb ifb_cb; /* needed by ifb, must be first */
	unsigned int	pkt_len;
};