commit bc3b04ef3b521346ba570aecaf50ca3740f458af
author Luis R. Rodriguez <mcgrof@do-not-panic.com> Tue Apr 01 21:22:41 2014 +0000
committer Luis R. Rodriguez <mcgrof@do-not-panic.com> Tue Apr 08 18:16:20 2014 -0700
tree b9fb54c7668737c8df31932c7339e0d63d0ce085
parent 3179ed459c15ca57791729ca00e6243ba1835ba7

backports: backport skb_unclone()

Pravin added this via commit 14bbd6a565 through v3.9. This is
a straight forward backport using the LINUX_BACKPORT() namespace.

mcgrof@ergon ~/linux-next (git::master)$ git describe --contains 14bbd6a565
v3.9-rc1~139^2~56

commit 14bbd6a565e1bcdc240d44687edb93f721cfdf99
Author: Pravin B Shelar <pshelar@nicira.com>
Date:   Thu Feb 14 09:44:49 2013 +0000

    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>

Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>

backport/backport-include/linux/skbuff.h

diff --git a/backport/backport-include/linux/skbuff.h b/backport/backport-include/linux/skbuff.h
index 7ea44f5..2a63e95 100644
--- a/backport/backport-include/linux/skbuff.h
+++ b/backport/backport-include/linux/skbuff.h
@@ -300,4 +300,15 @@
 #endif
 #endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,9,0) */
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,9,0)
+#define skb_unclone LINUX_BACKPORT(skb_unclone)
+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;
+}
+#endif
+
 #endif /* __BACKPORT_SKBUFF_H */