net: add __pskb_copy_fclone and pskb_copy_for_clone

There are several instances where a pskb_copy or __pskb_copy is
immediately followed by an skb_clone.

Add a couple of new functions to allow the copy skb to be allocated
from the fclone cache and thus speed up subsequent skb_clone calls.

Cc: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <antonio@meshcoding.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Arvid Brodin <arvid.brodin@alten.se>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Cc: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Allan Stephens <allan.stephens@windriver.com>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c705808..1f50bfe 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -744,7 +744,13 @@
 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
-struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, gfp_t gfp_mask);
+struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
+				   gfp_t gfp_mask, bool fclone);
+static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
+					  gfp_t gfp_mask)
+{
+	return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
+}
 
 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
@@ -2238,6 +2244,14 @@
 	return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
 }
 
+
+static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
+						  gfp_t gfp_mask)
+{
+	return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
+}
+
+
 /**
  *	skb_clone_writable - is the header of a clone writable
  *	@skb: buffer to check