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>

4 files changed, 4 insertions, 6 deletions

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 384233188ac1..bb02e176cb70 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -521,8 +521,7 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
 
         /* We are going to _remove_ AH header to keep sockets happy,
          * so... Later this can change. */
-        if (skb_cloned(skb) &&
-            pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+        if (skb_unclone(skb, GFP_ATOMIC))
                 goto out;
 
         skb->ip_summed = CHECKSUM_NONE;
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index c674f158efa8..b89a8c3186cd 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -368,7 +368,7 @@ nf_ct_frag6_reasm(struct frag_queue *fq, struct net_device *dev)
         }
 
         /* Head of list must not be cloned. */
-        if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
+        if (skb_unclone(head, GFP_ATOMIC)) {
                 pr_debug("skb is cloned but can't expand head");
                 goto out_oom;
         }
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index bab2c270f292..e354743ed426 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -404,7 +404,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
                 goto out_oversize;
 
         /* Head of list must not be cloned. */
-        if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+        if (skb_unclone(head, GFP_ATOMIC))
                 goto out_oom;
 
         /* If the first fragment is fragmented itself, we split
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 9f2095b19ad0..93c41a81c4c3 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -69,8 +69,7 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
                 goto out;
 
-        if (skb_cloned(skb) &&
-            (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+        if (err = skb_unclone(skb, GFP_ATOMIC))
                 goto out;
 
         if (x->props.flags & XFRM_STATE_DECAP_DSCP)