Update net/ to use sg helpers

[linux-2.6] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 39aba4862f2122838476b5b0c2f0762a8b8c1c06..38b03da5c1ca93d061cfe250195bbfc8898b9da6 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1362,22 +1362,21 @@ int skb_checksum_help(struct sk_buff *skb)
                goto out_set_summed;
        }
 
-       if (skb_cloned(skb)) {
+       offset = skb->csum_start - skb_headroom(skb);
+       BUG_ON(offset >= skb_headlen(skb));
+       csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+       offset += skb->csum_offset;
+       BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
+
+       if (skb_cloned(skb) &&
+           !skb_clone_writable(skb, offset + sizeof(__sum16))) {
                ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
                if (ret)
                        goto out;
        }
 
-       offset = skb->csum_start - skb_headroom(skb);
-       BUG_ON(offset > (int)skb->len);
-       csum = skb_checksum(skb, offset, skb->len-offset, 0);
-
-       offset = skb_headlen(skb) - offset;
-       BUG_ON(offset <= 0);
-       BUG_ON(skb->csum_offset + 2 > offset);
-
-       *(__sum16 *)(skb->head + skb->csum_start + skb->csum_offset) =
-               csum_fold(csum);
+       *(__sum16 *)(skb->data + offset) = csum_fold(csum);
 out_set_summed:
        skb->ip_summed = CHECKSUM_NONE;
 out: