[NETLINK]: Avoid pointer in netlink_run_queue

I was looking at Patrick's fix to inet_diag and it occured
to me that we're using a pointer argument to return values
unnecessarily in netlink_run_queue.  Changing it to return
the value will allow the compiler to generate better code
since the value won't have to be memory-backed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netlink.h

@@ -220,7 +220,7 @@ struct nl_info {
 	u32			pid;
 };
 
-extern void		netlink_run_queue(struct sock *sk, unsigned int *qlen,
+extern unsigned int	netlink_run_queue(struct sock *sk, unsigned int qlen,
 					  int (*cb)(struct sk_buff *,
 						    struct nlmsghdr *));
 extern int		nlmsg_notify(struct sock *sk, struct sk_buff *skb,

net/core/rtnetlink.c

@@ -1320,7 +1320,7 @@ static void rtnetlink_rcv(struct sock *sk, int len)
 
 	do {
 		mutex_lock(&rtnl_mutex);
-		netlink_run_queue(sk, &qlen, &rtnetlink_rcv_msg);
+		qlen = netlink_run_queue(sk, qlen, &rtnetlink_rcv_msg);
 		mutex_unlock(&rtnl_mutex);
 
 		netdev_run_todo();

net/ipv4/inet_diag.c

@@ -845,7 +845,7 @@ static void inet_diag_rcv(struct sock *sk, int len)
 
 	do {
 		mutex_lock(&inet_diag_mutex);
-		netlink_run_queue(sk, &qlen, &inet_diag_rcv_msg);
+		qlen = netlink_run_queue(sk, qlen, &inet_diag_rcv_msg);
 		mutex_unlock(&inet_diag_mutex);
 	} while (qlen);
 }

net/netfilter/nfnetlink.c

@@ -248,7 +248,7 @@ static void nfnetlink_rcv(struct sock *sk, int len)
 	do {
 		if (nfnl_trylock())
 			return;
-		netlink_run_queue(sk, &qlen, nfnetlink_rcv_msg);
+		qlen = netlink_run_queue(sk, qlen, nfnetlink_rcv_msg);
 		__nfnl_unlock();
 	} while (qlen);
 }

net/netlink/af_netlink.c

@@ -1629,7 +1629,7 @@ static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
 /**
  * nelink_run_queue - Process netlink receive queue.
  * @sk: Netlink socket containing the queue
- * @qlen: Place to store queue length upon entry
+ * @qlen: Initial queue length
  * @cb: Callback function invoked for each netlink message found
  *
  * Processes as much as there was in the queue upon entry and invokes
@@ -1639,35 +1639,37 @@ static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
  * returns with a qlen != 0.
  *
  * qlen must be initialized to 0 before the initial entry, afterwards
- * the function may be called repeatedly until qlen reaches 0.
+ * the function may be called repeatedly until the returned qlen is 0.
  *
  * The callback function may return -EINTR to signal that processing
  * of netlink messages shall be interrupted. In this case the message
  * currently being processed will NOT be requeued onto the receive
  * queue.
  */
-void netlink_run_queue(struct sock *sk, unsigned int *qlen,
-		       int (*cb)(struct sk_buff *, struct nlmsghdr *))
+unsigned int netlink_run_queue(struct sock *sk, unsigned int qlen,
+			       int (*cb)(struct sk_buff *, struct nlmsghdr *))
 {
 	struct sk_buff *skb;
 
-	if (!*qlen || *qlen > skb_queue_len(&sk->sk_receive_queue))
-		*qlen = skb_queue_len(&sk->sk_receive_queue);
+	if (!qlen || qlen > skb_queue_len(&sk->sk_receive_queue))
+		qlen = skb_queue_len(&sk->sk_receive_queue);
 
-	for (; *qlen; (*qlen)--) {
+	for (; qlen; qlen--) {
 		skb = skb_dequeue(&sk->sk_receive_queue);
 		if (netlink_rcv_skb(skb, cb)) {
 			if (skb->len)
 				skb_queue_head(&sk->sk_receive_queue, skb);
 			else {
 				kfree_skb(skb);
-				(*qlen)--;
+				qlen--;
 			}
 			break;
 		}
 
 		kfree_skb(skb);
 	}
+
+	return qlen;
 }
 
 /**

net/netlink/genetlink.c

@@ -485,7 +485,7 @@ static void genl_rcv(struct sock *sk, int len)
 	do {
 		if (genl_trylock())
 			return;
-		netlink_run_queue(sk, &qlen, genl_rcv_msg);
+		qlen = netlink_run_queue(sk, qlen, genl_rcv_msg);
 		genl_unlock();
 	} while (qlen && genl_sock && genl_sock->sk_receive_queue.qlen);
 }

net/xfrm/xfrm_user.c

@@ -1887,7 +1887,7 @@ static void xfrm_netlink_rcv(struct sock *sk, int len)
 
 	do {
 		mutex_lock(&xfrm_cfg_mutex);
-		netlink_run_queue(sk, &qlen, &xfrm_user_rcv_msg);
+		qlen = netlink_run_queue(sk, qlen, &xfrm_user_rcv_msg);
 		mutex_unlock(&xfrm_cfg_mutex);
 
 	} while (qlen);