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
          */