xfrm: prefer secpath_set over secpath_dup

secpath_set is a wrapper for secpath_dup that will not perform
an allocation if the secpath attached to the skb has a reference count
of one, i.e., it doesn't need to be COW'ed.

Also, secpath_dup doesn't attach the secpath to the skb, it leaves
this to the caller.

Use secpath_set in places that immediately assign the return value to
skb.

This allows to remove skb->sp without touching these spots again.

secpath_dup can eventually be removed in followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 5 deletions

diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 4ae87c5ce2e3..757c4d11983b 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -218,19 +218,16 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
         if (xfrm_dev_offload_ok(skb, x)) {
                 struct sec_path *sp;
 
-                sp = secpath_dup(skb->sp);
+                sp = secpath_set(skb);
                 if (!sp) {
                         XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
                         kfree_skb(skb);
                         return -ENOMEM;
                 }
-                if (skb->sp)
-                        secpath_put(skb->sp);
-                skb->sp = sp;
                 skb->encapsulation = 1;
 
                 sp->olen++;
-                sp->xvec[skb->sp->len++] = x;
+                sp->xvec[sp->len++] = x;
                 xfrm_state_hold(x);
 
                 if (skb_is_gso(skb)) {