1 files changed, 0 insertions, 105 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 71ce33decd97..62018ea6f45f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -400,7 +400,6 @@ void tcp_init_sock(struct sock *sk)
 
 	tp->out_of_order_queue = RB_ROOT;
 	tcp_init_xmit_timers(sk);
-	tcp_prequeue_init(tp);
 	INIT_LIST_HEAD(&tp->tsq_node);
 
 	icsk->icsk_rto = TCP_TIMEOUT_INIT;
@@ -1525,20 +1524,6 @@ static void tcp_cleanup_rbuf(struct sock *sk, int copied)
 		tcp_send_ack(sk);
 }
 
-static void tcp_prequeue_process(struct sock *sk)
-{
-	struct sk_buff *skb;
-	struct tcp_sock *tp = tcp_sk(sk);
-
-	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
-
-	while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
-		sk_backlog_rcv(sk, skb);
-
-	/* Clear memory counter. */
-	tp->ucopy.memory = 0;
-}
-
 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
 {
 	struct sk_buff *skb;
@@ -1671,7 +1656,6 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 	int err;
 	int target;		/* Read at least this many bytes */
 	long timeo;
-	struct task_struct *user_recv = NULL;
 	struct sk_buff *skb, *last;
 	u32 urg_hole = 0;
 
@@ -1806,51 +1790,6 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 
 		tcp_cleanup_rbuf(sk, copied);
 
-		if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
-			/* Install new reader */
-			if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
-				user_recv = current;
-				tp->ucopy.task = user_recv;
-				tp->ucopy.msg = msg;
-			}
-
-			tp->ucopy.len = len;
-
-			WARN_ON(tp->copied_seq != tp->rcv_nxt &&
-				!(flags & (MSG_PEEK | MSG_TRUNC)));
-
-			/* Ugly... If prequeue is not empty, we have to
-			 * process it before releasing socket, otherwise
-			 * order will be broken at second iteration.
-			 * More elegant solution is required!!!
-			 *
-			 * Look: we have the following (pseudo)queues:
-			 *
-			 * 1. packets in flight
-			 * 2. backlog
-			 * 3. prequeue
-			 * 4. receive_queue
-			 *
-			 * Each queue can be processed only if the next ones
-			 * are empty. At this point we have empty receive_queue.
-			 * But prequeue _can_ be not empty after 2nd iteration,
-			 * when we jumped to start of loop because backlog
-			 * processing added something to receive_queue.
-			 * We cannot release_sock(), because backlog contains
-			 * packets arrived _after_ prequeued ones.
-			 *
-			 * Shortly, algorithm is clear --- to process all
-			 * the queues in order. We could make it more directly,
-			 * requeueing packets from backlog to prequeue, if
-			 * is not empty. It is more elegant, but eats cycles,
-			 * unfortunately.
-			 */
-			if (!skb_queue_empty(&tp->ucopy.prequeue))
-				goto do_prequeue;
-
-			/* __ Set realtime policy in scheduler __ */
-		}
-
 		if (copied >= target) {
 			/* Do not sleep, just process backlog. */
 			release_sock(sk);
@@ -1859,31 +1798,6 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 			sk_wait_data(sk, &timeo, last);
 		}
 
-		if (user_recv) {
-			int chunk;
-
-			/* __ Restore normal policy in scheduler __ */
-
-			chunk = len - tp->ucopy.len;
-			if (chunk != 0) {
-				NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
-				len -= chunk;
-				copied += chunk;
-			}
-
-			if (tp->rcv_nxt == tp->copied_seq &&
-			    !skb_queue_empty(&tp->ucopy.prequeue)) {
-do_prequeue:
-				tcp_prequeue_process(sk);
-
-				chunk = len - tp->ucopy.len;
-				if (chunk != 0) {
-					NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
-					len -= chunk;
-					copied += chunk;
-				}
-			}
-		}
 		if ((flags & MSG_PEEK) &&
 		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
 			net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
@@ -1955,25 +1869,6 @@ skip_copy:
 		break;
 	} while (len > 0);
 
-	if (user_recv) {
-		if (!skb_queue_empty(&tp->ucopy.prequeue)) {
-			int chunk;
-
-			tp->ucopy.len = copied > 0 ? len : 0;
-
-			tcp_prequeue_process(sk);
-
-			if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
-				NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
-				len -= chunk;
-				copied += chunk;
-			}
-		}
-
-		tp->ucopy.task = NULL;
-		tp->ucopy.len = 0;
-	}
-
 	/* According to UNIX98, msg_name/msg_namelen are ignored
 	 * on connected socket. I was just happy when found this 8) --ANK
 	 */