RE: [PATCH net-next 1/3] skbuff: Add skb_list_linearize()

["Harout Hedeshian" <harouth@codeaurora.org>]

> -----Original Message-----
> From: netdev-owner@vger.kernel.org [mailto:netdev-owner@vger.kernel.org]
> On Behalf Of Pravin B Shelar
> Sent: Tuesday, January 20, 2015 1:26 PM
> To: davem@davemloft.net
> Cc: netdev@vger.kernel.org; Pravin B Shelar
> Subject: [PATCH net-next 1/3] skbuff: Add skb_list_linearize()
> 
> similar to skb_linearize(), this API takes skb list as arg and linearize
> it into one big skb. STT driver patch will use this.
> 
> Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
> ---
>  include/linux/skbuff.h |  2 ++
>  net/core/skbuff.c      | 35 +++++++++++++++++++++++++++++++++++
>  2 files changed, 37 insertions(+)
> 
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index
> 85ab7d7..c9194c1 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -2532,6 +2532,8 @@ static inline int skb_linearize(struct sk_buff
> *skb)
>  	return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;  }
> 
> +int skb_list_linearize(struct sk_buff *head, gfp_t gfp_mask);
> +
>  /**
>   * skb_has_shared_frag - can any frag be overwritten
>   * @skb: buffer to test
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c index
> 56db472..9ef2881 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -2329,6 +2329,41 @@ void skb_copy_and_csum_dev(const struct sk_buff
> *skb, u8 *to)  }  EXPORT_SYMBOL(skb_copy_and_csum_dev);
> 
> +int skb_list_linearize(struct sk_buff *head, gfp_t gfp_mask) {
> +	struct sk_buff *skb;
> +	int tlen = 0;
> +	int err;
> +
> +	err = skb_linearize(head);
> +	if (err)
> +		return err;
> +
> +	skb = head->next;
> +	while (skb) {
> +		tlen += skb->len;
> +		skb = skb->next;
> +	}
> +	err = pskb_expand_head(head, 0, tlen, gfp_mask);
> +	if (err)
> +		return err;
> +
> +	skb = head->next;
> +	while (skb) {
> +		err = skb_copy_bits(skb, 0, skb_tail_pointer(head),
skb->len);
> +		if (err)
> +			return err;
> +		head->tail += skb->len;
> +		skb = skb->next;
> +	}
> +	kfree_skb_list(head->next);
> +	head->next = NULL;
> +	head->len += tlen;
> +	head->truesize = SKB_TRUESIZE(skb_end_offset(head));
> +	return 0;
> +}
> +EXPORT_SYMBOL(skb_list_linearize);
> +
>  /**
>   *	skb_dequeue - remove from the head of the queue
>   *	@list: list to dequeue from
> --
> 1.9.1
> 

This looks useful for us as well.

Acked-by: Harout Hedeshian <harouth@codeaurora.org>

Thanks,
Harout

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