]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - net/ipv4/tcp_input.c
tcp: kill pointless urg_mode
[linux-2.6-omap-h63xx.git] / net / ipv4 / tcp_input.c
index f79a51607292bc7a39dd45fd3389139533af49a2..c19f429dc4434f9cfc2b18bfb1644cba0e1c03f7 100644 (file)
@@ -979,6 +979,39 @@ static void tcp_update_reordering(struct sock *sk, const int metric,
        }
 }
 
+/* This must be called before lost_out is incremented */
+static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb)
+{
+       if ((tp->retransmit_skb_hint == NULL) ||
+           before(TCP_SKB_CB(skb)->seq,
+                  TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
+               tp->retransmit_skb_hint = skb;
+
+       if (!tp->lost_out ||
+           after(TCP_SKB_CB(skb)->end_seq, tp->retransmit_high))
+               tp->retransmit_high = TCP_SKB_CB(skb)->end_seq;
+}
+
+static void tcp_skb_mark_lost(struct tcp_sock *tp, struct sk_buff *skb)
+{
+       if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) {
+               tcp_verify_retransmit_hint(tp, skb);
+
+               tp->lost_out += tcp_skb_pcount(skb);
+               TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+       }
+}
+
+void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb)
+{
+       tcp_verify_retransmit_hint(tp, skb);
+
+       if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) {
+               tp->lost_out += tcp_skb_pcount(skb);
+               TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+       }
+}
+
 /* This procedure tags the retransmission queue when SACKs arrive.
  *
  * We have three tag bits: SACKED(S), RETRANS(R) and LOST(L).
@@ -1155,13 +1188,7 @@ static void tcp_mark_lost_retrans(struct sock *sk)
                        TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                        tp->retrans_out -= tcp_skb_pcount(skb);
 
-                       /* clear lost hint */
-                       tp->retransmit_skb_hint = NULL;
-
-                       if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) {
-                               tp->lost_out += tcp_skb_pcount(skb);
-                               TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
-                       }
+                       tcp_skb_mark_lost_uncond_verify(tp, skb);
                        NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT);
                } else {
                        if (before(ack_seq, new_low_seq))
@@ -1271,9 +1298,6 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
                                        ~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
                                tp->lost_out -= tcp_skb_pcount(skb);
                                tp->retrans_out -= tcp_skb_pcount(skb);
-
-                               /* clear lost hint */
-                               tp->retransmit_skb_hint = NULL;
                        }
                } else {
                        if (!(sacked & TCPCB_RETRANS)) {
@@ -1292,9 +1316,6 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
                        if (sacked & TCPCB_LOST) {
                                TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
                                tp->lost_out -= tcp_skb_pcount(skb);
-
-                               /* clear lost hint */
-                               tp->retransmit_skb_hint = NULL;
                        }
                }
 
@@ -1324,7 +1345,6 @@ static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
        if (dup_sack && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)) {
                TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
                tp->retrans_out -= tcp_skb_pcount(skb);
-               tp->retransmit_skb_hint = NULL;
        }
 
        return flag;
@@ -1726,6 +1746,8 @@ int tcp_use_frto(struct sock *sk)
                return 0;
 
        skb = tcp_write_queue_head(sk);
+       if (tcp_skb_is_last(sk, skb))
+               return 1;
        skb = tcp_write_queue_next(sk, skb);    /* Skips head */
        tcp_for_write_queue_from(skb, sk) {
                if (skb == tcp_send_head(sk))
@@ -1867,6 +1889,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
                if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) {
                        TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                        tp->lost_out += tcp_skb_pcount(skb);
+                       tp->retransmit_high = TCP_SKB_CB(skb)->end_seq;
                }
        }
        tcp_verify_left_out(tp);
@@ -1883,7 +1906,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
        tp->high_seq = tp->snd_nxt;
        TCP_ECN_queue_cwr(tp);
 
-       tcp_clear_retrans_hints_partial(tp);
+       tcp_clear_all_retrans_hints(tp);
 }
 
 static void tcp_clear_retrans_partial(struct tcp_sock *tp)
@@ -1934,12 +1957,11 @@ void tcp_enter_loss(struct sock *sk, int how)
                /* Push undo marker, if it was plain RTO and nothing
                 * was retransmitted. */
                tp->undo_marker = tp->snd_una;
-               tcp_clear_retrans_hints_partial(tp);
        } else {
                tp->sacked_out = 0;
                tp->fackets_out = 0;
-               tcp_clear_all_retrans_hints(tp);
        }
+       tcp_clear_all_retrans_hints(tp);
 
        tcp_for_write_queue(skb, sk) {
                if (skb == tcp_send_head(sk))
@@ -1952,6 +1974,7 @@ void tcp_enter_loss(struct sock *sk, int how)
                        TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED;
                        TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                        tp->lost_out += tcp_skb_pcount(skb);
+                       tp->retransmit_high = TCP_SKB_CB(skb)->end_seq;
                }
        }
        tcp_verify_left_out(tp);
@@ -2157,19 +2180,6 @@ static int tcp_time_to_recover(struct sock *sk)
        return 0;
 }
 
-/* RFC: This is from the original, I doubt that this is necessary at all:
- * clear xmit_retrans hint if seq of this skb is beyond hint. How could we
- * retransmitted past LOST markings in the first place? I'm not fully sure
- * about undo and end of connection cases, which can cause R without L?
- */
-static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb)
-{
-       if ((tp->retransmit_skb_hint != NULL) &&
-           before(TCP_SKB_CB(skb)->seq,
-                  TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
-               tp->retransmit_skb_hint = NULL;
-}
-
 /* Mark head of queue up as lost. With RFC3517 SACK, the packets is
  * is against sacked "cnt", otherwise it's against facked "cnt"
  */
@@ -2217,11 +2227,7 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
                        cnt = packets;
                }
 
-               if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_SACKED_ACKED|TCPCB_LOST))) {
-                       TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
-                       tp->lost_out += tcp_skb_pcount(skb);
-                       tcp_verify_retransmit_hint(tp, skb);
-               }
+               tcp_skb_mark_lost(tp, skb);
        }
        tcp_verify_left_out(tp);
 }
@@ -2263,11 +2269,7 @@ static void tcp_update_scoreboard(struct sock *sk, int fast_rexmit)
                        if (!tcp_skb_timedout(sk, skb))
                                break;
 
-                       if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_SACKED_ACKED|TCPCB_LOST))) {
-                               TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
-                               tp->lost_out += tcp_skb_pcount(skb);
-                               tcp_verify_retransmit_hint(tp, skb);
-                       }
+                       tcp_skb_mark_lost(tp, skb);
                }
 
                tp->scoreboard_skb_hint = skb;
@@ -2378,10 +2380,6 @@ static void tcp_undo_cwr(struct sock *sk, const int undo)
        }
        tcp_moderate_cwnd(tp);
        tp->snd_cwnd_stamp = tcp_time_stamp;
-
-       /* There is something screwy going on with the retrans hints after
-          an undo */
-       tcp_clear_all_retrans_hints(tp);
 }
 
 static inline int tcp_may_undo(struct tcp_sock *tp)
@@ -2838,7 +2836,8 @@ static u32 tcp_tso_acked(struct sock *sk, struct sk_buff *skb)
  * is before the ack sequence we can discard it as it's confirmed to have
  * arrived at the other end.
  */
-static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
+static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
+                              u32 prior_snd_una)
 {
        struct tcp_sock *tp = tcp_sk(sk);
        const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -2848,6 +2847,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
        int flag = 0;
        u32 pkts_acked = 0;
        u32 reord = tp->packets_out;
+       u32 prior_sacked = tp->sacked_out;
        s32 seq_rtt = -1;
        s32 ca_seq_rtt = -1;
        ktime_t last_ackt = net_invalid_timestamp();
@@ -2904,9 +2904,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
                if (sacked & TCPCB_LOST)
                        tp->lost_out -= acked_pcount;
 
-               if (unlikely(tp->urg_mode && !before(end_seq, tp->snd_up)))
-                       tp->urg_mode = 0;
-
                tp->packets_out -= acked_pcount;
                pkts_acked += acked_pcount;
 
@@ -2929,9 +2926,16 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
 
                tcp_unlink_write_queue(skb, sk);
                sk_wmem_free_skb(sk, skb);
-               tcp_clear_all_retrans_hints(tp);
+               tp->scoreboard_skb_hint = NULL;
+               if (skb == tp->retransmit_skb_hint)
+                       tp->retransmit_skb_hint = NULL;
+               if (skb == tp->lost_skb_hint)
+                       tp->lost_skb_hint = NULL;
        }
 
+       if (likely(between(tp->snd_up, prior_snd_una, tp->snd_una)))
+               tp->snd_up = tp->snd_una;
+
        if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
                flag |= FLAG_SACK_RENEGING;
 
@@ -2948,6 +2952,15 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets)
                        /* Non-retransmitted hole got filled? That's reordering */
                        if (reord < prior_fackets)
                                tcp_update_reordering(sk, tp->fackets_out - reord, 0);
+
+                       /* No need to care for underflows here because
+                        * the lost_skb_hint gets NULLed if we're past it
+                        * (or something non-trivial happened)
+                        */
+                       if (tcp_is_fack(tp))
+                               tp->lost_cnt_hint -= pkts_acked;
+                       else
+                               tp->lost_cnt_hint -= prior_sacked - tp->sacked_out;
                }
 
                tp->fackets_out -= min(pkts_acked, tp->fackets_out);
@@ -3299,7 +3312,7 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
                goto no_queue;
 
        /* See if we can take anything off of the retransmit queue. */
-       flag |= tcp_clean_rtx_queue(sk, prior_fackets);
+       flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una);
 
        if (tp->frto_counter)
                frto_cwnd = tcp_process_frto(sk, flag);
@@ -4146,7 +4159,7 @@ drop:
                                skb1 = skb1->prev;
                        }
                }
-               __skb_insert(skb, skb1, skb1->next, &tp->out_of_order_queue);
+               __skb_queue_after(&tp->out_of_order_queue, skb1, skb);
 
                /* And clean segments covered by new one as whole. */
                while ((skb1 = skb->next) !=
@@ -4244,7 +4257,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list,
                memcpy(nskb->head, skb->head, header);
                memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
                TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
-               __skb_insert(nskb, skb->prev, skb, list);
+               __skb_queue_before(list, skb, nskb);
                skb_set_owner_r(nskb, sk);
 
                /* Copy data, releasing collapsed skbs. */