ahci: jmb361 has only one port

[linux-2.6] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 26c936930e927fe42ba64da212492b522885e424..cad73b7dfef07798ddc0b8debba24c9aad94c53b 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1392,9 +1392,9 @@ static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
 
        if (before(next_dup->start_seq, skip_to_seq)) {
                skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq, fack_count);
-               tcp_sacktag_walk(skb, sk, NULL,
-                                next_dup->start_seq, next_dup->end_seq,
-                                1, fack_count, reord, flag);
+               skb = tcp_sacktag_walk(skb, sk, NULL,
+                                    next_dup->start_seq, next_dup->end_seq,
+                                    1, fack_count, reord, flag);
        }
 
        return skb;
@@ -1842,9 +1842,16 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
                        TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                }
 
-               /* Don't lost mark skbs that were fwd transmitted after RTO */
-               if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) &&
-                   !after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark)) {
+               /* Marking forward transmissions that were made after RTO lost
+                * can cause unnecessary retransmissions in some scenarios,
+                * SACK blocks will mitigate that in some but not in all cases.
+                * We used to not mark them but it was causing break-ups with
+                * receivers that do only in-order receival.
+                *
+                * TODO: we could detect presence of such receiver and select
+                * different behavior per flow.
+                */
+               if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) {
                        TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                        tp->lost_out += tcp_skb_pcount(skb);
                }
@@ -1860,7 +1867,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
        tp->reordering = min_t(unsigned int, tp->reordering,
                               sysctl_tcp_reordering);
        tcp_set_ca_state(sk, TCP_CA_Loss);
-       tp->high_seq = tp->frto_highmark;
+       tp->high_seq = tp->snd_nxt;
        TCP_ECN_queue_cwr(tp);
 
        tcp_clear_retrans_hints_partial(tp);
@@ -2476,28 +2483,34 @@ static inline void tcp_complete_cwr(struct sock *sk)
        tcp_ca_event(sk, CA_EVENT_COMPLETE_CWR);
 }
 
+static void tcp_try_keep_open(struct sock *sk)
+{
+       struct tcp_sock *tp = tcp_sk(sk);
+       int state = TCP_CA_Open;
+
+       if (tcp_left_out(tp) || tp->retrans_out || tp->undo_marker)
+               state = TCP_CA_Disorder;
+
+       if (inet_csk(sk)->icsk_ca_state != state) {
+               tcp_set_ca_state(sk, state);
+               tp->high_seq = tp->snd_nxt;
+       }
+}
+
 static void tcp_try_to_open(struct sock *sk, int flag)
 {
        struct tcp_sock *tp = tcp_sk(sk);
 
        tcp_verify_left_out(tp);
 
-       if (tp->retrans_out == 0)
+       if (!tp->frto_counter && tp->retrans_out == 0)
                tp->retrans_stamp = 0;
 
        if (flag & FLAG_ECE)
                tcp_enter_cwr(sk, 1);
 
        if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) {
-               int state = TCP_CA_Open;
-
-               if (tcp_left_out(tp) || tp->retrans_out || tp->undo_marker)
-                       state = TCP_CA_Disorder;
-
-               if (inet_csk(sk)->icsk_ca_state != state) {
-                       tcp_set_ca_state(sk, state);
-                       tp->high_seq = tp->snd_nxt;
-               }
+               tcp_try_keep_open(sk);
                tcp_moderate_cwnd(tp);
        } else {
                tcp_cwnd_down(sk, flag);
@@ -3303,8 +3316,11 @@ no_queue:
        return 1;
 
 old_ack:
-       if (TCP_SKB_CB(skb)->sacked)
+       if (TCP_SKB_CB(skb)->sacked) {
                tcp_sacktag_write_queue(sk, skb, prior_snd_una);
+               if (icsk->icsk_ca_state == TCP_CA_Open)
+                       tcp_try_keep_open(sk);
+       }
 
 uninteresting_ack:
        SOCK_DEBUG(sk, "Ack %u out of %u:%u\n", ack, tp->snd_una, tp->snd_nxt);
@@ -4525,49 +4541,6 @@ static void tcp_urg(struct sock *sk, struct sk_buff *skb, struct tcphdr *th)
        }
 }
 
-static int tcp_defer_accept_check(struct sock *sk)
-{
-       struct tcp_sock *tp = tcp_sk(sk);
-
-       if (tp->defer_tcp_accept.request) {
-               int queued_data =  tp->rcv_nxt - tp->copied_seq;
-               int hasfin =  !skb_queue_empty(&sk->sk_receive_queue) ?
-                       tcp_hdr((struct sk_buff *)
-                               sk->sk_receive_queue.prev)->fin : 0;
-
-               if (queued_data && hasfin)
-                       queued_data--;
-
-               if (queued_data &&
-                   tp->defer_tcp_accept.listen_sk->sk_state == TCP_LISTEN) {
-                       if (sock_flag(sk, SOCK_KEEPOPEN)) {
-                               inet_csk_reset_keepalive_timer(sk,
-                                                              keepalive_time_when(tp));
-                       } else {
-                               inet_csk_delete_keepalive_timer(sk);
-                       }
-
-                       inet_csk_reqsk_queue_add(
-                               tp->defer_tcp_accept.listen_sk,
-                               tp->defer_tcp_accept.request,
-                               sk);
-
-                       tp->defer_tcp_accept.listen_sk->sk_data_ready(
-                               tp->defer_tcp_accept.listen_sk, 0);
-
-                       sock_put(tp->defer_tcp_accept.listen_sk);
-                       sock_put(sk);
-                       tp->defer_tcp_accept.listen_sk = NULL;
-                       tp->defer_tcp_accept.request = NULL;
-               } else if (hasfin ||
-                          tp->defer_tcp_accept.listen_sk->sk_state != TCP_LISTEN) {
-                       tcp_reset(sk);
-                       return -1;
-               }
-       }
-       return 0;
-}
-
 static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen)
 {
        struct tcp_sock *tp = tcp_sk(sk);
@@ -4928,8 +4901,6 @@ step5:
 
        tcp_data_snd_check(sk);
        tcp_ack_snd_check(sk);
-
-       tcp_defer_accept_check(sk);
        return 0;
 
 csum_error: