- if (delta || skb_cloned(skb))
- return pskb_expand_head(skb, (delta + (NET_SKB_PAD-1)) &
- ~(NET_SKB_PAD-1), 0, GFP_ATOMIC);
- return 0;
+/**
+ * skb_cow_head - skb_cow but only making the head writable
+ * @skb: buffer to cow
+ * @headroom: needed headroom
+ *
+ * This function is identical to skb_cow except that we replace the
+ * skb_cloned check by skb_header_cloned. It should be used when
+ * you only need to push on some header and do not need to modify
+ * the data.
+ */
+static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
+{
+ return __skb_cow(skb, headroom, skb_header_cloned(skb));