xfrm: move the checking for old xfrm_policy hold_queue to beginning

if hold_queue of old xfrm_policy is NULL, return directly, then not need to
run other codes, especially take the spin lock

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 435bc0d..3d264e5 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -700,6 +700,9 @@ static void xfrm_policy_requeue(struct xfrm_policy *old,
        struct xfrm_policy_queue *pq = &old->polq;
        struct sk_buff_head list;
 
+       if (skb_queue_empty(&pq->hold_queue))
+               return;
+
        __skb_queue_head_init(&list);
 
        spin_lock_bh(&pq->hold_queue.lock);
@@ -708,9 +711,6 @@ static void xfrm_policy_requeue(struct xfrm_policy *old,
                xfrm_pol_put(old);
        spin_unlock_bh(&pq->hold_queue.lock);
 
-       if (skb_queue_empty(&list))
-               return;
-
        pq = &new->polq;
 
        spin_lock_bh(&pq->hold_queue.lock);