[NET]: Transform skb_queue_len() binary tests into skb_queue_empty()

This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 11 insertions, 13 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 29894c74916..ddb6ce4ecff 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1105,7 +1105,7 @@ static void tcp_prequeue_process(struct sock *sk)
 	struct sk_buff *skb;
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	NET_ADD_STATS_USER(LINUX_MIB_TCPPREQUEUED, skb_queue_len(&tp->ucopy.prequeue));
+	NET_INC_STATS_USER(LINUX_MIB_TCPPREQUEUED);
 
 	/* RX process wants to run with disabled BHs, though it is not
 	 * necessary */
@@ -1369,7 +1369,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			 * is not empty. It is more elegant, but eats cycles,
 			 * unfortunately.
 			 */
-			if (skb_queue_len(&tp->ucopy.prequeue))
+			if (!skb_queue_empty(&tp->ucopy.prequeue))
 				goto do_prequeue;
 
 			/* __ Set realtime policy in scheduler __ */
@@ -1394,7 +1394,7 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			}
 
 			if (tp->rcv_nxt == tp->copied_seq &&
-			    skb_queue_len(&tp->ucopy.prequeue)) {
+			    !skb_queue_empty(&tp->ucopy.prequeue)) {
 do_prequeue:
 				tcp_prequeue_process(sk);
 
@@ -1476,7 +1476,7 @@ skip_copy:
 	} while (len > 0);
 
 	if (user_recv) {
-		if (skb_queue_len(&tp->ucopy.prequeue)) {
+		if (!skb_queue_empty(&tp->ucopy.prequeue)) {
 			int chunk;
 
 			tp->ucopy.len = copied > 0 ? len : 0;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8de2f1071c2..53a8a5399f1 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2802,7 +2802,7 @@ static void tcp_sack_remove(struct tcp_sock *tp)
 	int this_sack;
 
 	/* Empty ofo queue, hence, all the SACKs are eaten. Clear. */
-	if (skb_queue_len(&tp->out_of_order_queue) == 0) {
+	if (skb_queue_empty(&tp->out_of_order_queue)) {
 		tp->rx_opt.num_sacks = 0;
 		tp->rx_opt.eff_sacks = tp->rx_opt.dsack;
 		return;
@@ -2935,13 +2935,13 @@ queue_and_out:
 		if(th->fin)
 			tcp_fin(skb, sk, th);
 
-		if (skb_queue_len(&tp->out_of_order_queue)) {
+		if (!skb_queue_empty(&tp->out_of_order_queue)) {
 			tcp_ofo_queue(sk);
 
 			/* RFC2581. 4.2. SHOULD send immediate ACK, when
 			 * gap in queue is filled.
 			 */
-			if (!skb_queue_len(&tp->out_of_order_queue))
+			if (skb_queue_empty(&tp->out_of_order_queue))
 				tp->ack.pingpong = 0;
 		}
 
@@ -3249,9 +3249,8 @@ static int tcp_prune_queue(struct sock *sk)
 	 * This must not ever occur. */
 
 	/* First, purge the out_of_order queue. */
-	if (skb_queue_len(&tp->out_of_order_queue)) {
-		NET_ADD_STATS_BH(LINUX_MIB_OFOPRUNED, 
-				 skb_queue_len(&tp->out_of_order_queue));
+	if (!skb_queue_empty(&tp->out_of_order_queue)) {
+		NET_INC_STATS_BH(LINUX_MIB_OFOPRUNED);
 		__skb_queue_purge(&tp->out_of_order_queue);
 
 		/* Reset SACK state.  A conforming SACK implementation will
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index b127b449856..0084227438c 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -231,11 +231,10 @@ static void tcp_delack_timer(unsigned long data)
 	}
 	tp->ack.pending &= ~TCP_ACK_TIMER;
 
-	if (skb_queue_len(&tp->ucopy.prequeue)) {
+	if (!skb_queue_empty(&tp->ucopy.prequeue)) {
 		struct sk_buff *skb;
 
-		NET_ADD_STATS_BH(LINUX_MIB_TCPSCHEDULERFAILED, 
-				 skb_queue_len(&tp->ucopy.prequeue));
+		NET_INC_STATS_BH(LINUX_MIB_TCPSCHEDULERFAILED);
 
 		while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
 			sk->sk_backlog_rcv(sk, skb);