On Fri, 1 Feb 2008, Ilpo Järvinen wrote:
> @@ -1322,6 +1324,206 @@ static int tcp_sacktag_one(struct sk_buff *skb,
> struct sock *sk,
> return flag;
> }
>
> +/* Attempts to shift up to shiftlen worth of bytes from prev to skb.
> + * Returns number bytes shifted.
> + *
> + * TODO: in case the prev runs out of frag space, operation could be
> + * made to return with a partial result (would allow tighter packing).
> + */
> +static int skb_shift(struct sk_buff *prev, struct sk_buff *skb,
> + unsigned int shiftlen)
> +{
> + int i, to, merge;
> + unsigned int todo;
> + struct skb_frag_struct *from, *fragto;
> +
> + if (skb_cloned(skb) || skb_cloned(prev))
> + return 0;
> +
> + todo = shiftlen;
> + i = 0;
> + from = &skb_shinfo(skb)->frags[i];
> + to = skb_shinfo(prev)->nr_frags;
> +
> + merge = to - 1;
> + if (!skb_can_coalesce(prev, merge + 1, from->page, from->page_offset))
> + merge = -1;
> + if (merge >= 0) {
> + i++;
> + if (from->size >= shiftlen)
> + goto onlymerge;
> + todo -= from->size;
> + }
> +
> + /* Skip full, not-fitting skb to avoid expensive operations */
> + if ((shiftlen == skb->len) &&
> + (skb_shinfo(skb)->nr_frags - merge) < (MAX_SKB_FRAGS - to))
Before somebody else notices it:
s/merge/i/, a leftover from flag -> idx conversion.
> + return 0;
> +
> + while (todo && (i < skb_shinfo(skb)->nr_frags)) {
> + if (to == MAX_SKB_FRAGS)
> + return 0;
> +
--
i.
