net: Add skb_unclone() helper function.

This function will be used in next GRE_GSO patch. This patch does
not change any functionality.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Eric Dumazet <edumazet@google.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 9da99520ccd5..ca6ee7d93edb 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -804,6 +804,16 @@ static inline int skb_cloned(const struct sk_buff *skb)
                (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
 }
 
+static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
+{
+        might_sleep_if(pri & __GFP_WAIT);
+
+        if (skb_cloned(skb))
+                return pskb_expand_head(skb, 0, 0, pri);
+
+        return 0;
+}
+
 /**
  *      skb_header_cloned - is the header a clone
  *      @skb: buffer to check