gro: Open-code final pskb_may_pull
As we know the only packets which need the final pskb_may_pull
are completely non-linear, and have all the required bits in
frag0, we can perform a straight memcpy instead of going through
pskb_may_pull and doing skb_copy_bits.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index cd29e61..ed4550f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2452,10 +2452,25 @@
ret = GRO_HELD;
pull:
- if (unlikely(!pskb_may_pull(skb, skb_gro_offset(skb)))) {
- if (napi->gro_list == skb)
- napi->gro_list = skb->next;
- ret = GRO_DROP;
+ if (skb_headlen(skb) < skb_gro_offset(skb)) {
+ int grow = skb_gro_offset(skb) - skb_headlen(skb);
+
+ BUG_ON(skb->end - skb->tail < grow);
+
+ memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
+
+ skb->tail += grow;
+ skb->data_len -= grow;
+
+ skb_shinfo(skb)->frags[0].page_offset += grow;
+ skb_shinfo(skb)->frags[0].size -= grow;
+
+ if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
+ put_page(skb_shinfo(skb)->frags[0].page);
+ memmove(skb_shinfo(skb)->frags,
+ skb_shinfo(skb)->frags + 1,
+ --skb_shinfo(skb)->nr_frags);
+ }
}
ok: