[TCP]: Separate lost_retrans loop into own function

Follows own function for each task principle, this is really
somewhat separate task being done in sacktag. Also reduces
indentation.

In addition, added ack_seq local var to break some long
lines & fixed coding style things.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 43 insertions, 37 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e8c39488cf58..101054cb13e9 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1106,6 +1106,47 @@ static int tcp_is_sackblock_valid(struct tcp_sock *tp, int is_dsack,
         return !before(start_seq, end_seq - tp->max_window);
 }
 
+/* Check for lost retransmit. This superb idea is borrowed from "ratehalving".
+ * Event "C". Later note: FACK people cheated me again 8), we have to account
+ * for reordering! Ugly, but should help.
+ */
+static int tcp_mark_lost_retrans(struct sock *sk, u32 lost_retrans)
+{
+        struct tcp_sock *tp = tcp_sk(sk);
+        struct sk_buff *skb;
+        int flag = 0;
+
+        tcp_for_write_queue(skb, sk) {
+                u32 ack_seq = TCP_SKB_CB(skb)->ack_seq;
+
+                if (skb == tcp_send_head(sk))
+                        break;
+                if (after(TCP_SKB_CB(skb)->seq, lost_retrans))
+                        break;
+                if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
+                        continue;
+
+                if ((TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) &&
+                    after(lost_retrans, ack_seq) &&
+                    (tcp_is_fack(tp) ||
+                     !before(lost_retrans,
+                             ack_seq + tp->reordering * tp->mss_cache))) {
+                        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;
+                                flag |= FLAG_DATA_SACKED;
+                                NET_INC_STATS_BH(LINUX_MIB_TCPLOSTRETRANSMIT);
+                        }
+                }
+        }
+        return flag;
+}
 
 static int tcp_check_dsack(struct tcp_sock *tp, struct sk_buff *ack_skb,
                            struct tcp_sack_block_wire *sp, int num_sacks,
@@ -1422,43 +1463,8 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
                 }
         }
 
-        /* Check for lost retransmit. This superb idea is
-         * borrowed from "ratehalving". Event "C".
-         * Later note: FACK people cheated me again 8),
-         * we have to account for reordering! Ugly,
-         * but should help.
-         */
-        if (lost_retrans && icsk->icsk_ca_state == TCP_CA_Recovery) {
-                struct sk_buff *skb;
-
-                tcp_for_write_queue(skb, sk) {
-                        if (skb == tcp_send_head(sk))
-                                break;
-                        if (after(TCP_SKB_CB(skb)->seq, lost_retrans))
-                                break;
-                        if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
-                                continue;
-                        if ((TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS) &&
-                            after(lost_retrans, TCP_SKB_CB(skb)->ack_seq) &&
-                            (tcp_is_fack(tp) ||
-                             !before(lost_retrans,
-                                     TCP_SKB_CB(skb)->ack_seq + tp->reordering *
-                                     tp->mss_cache))) {
-                                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;
-                                        flag |= FLAG_DATA_SACKED;
-                                        NET_INC_STATS_BH(LINUX_MIB_TCPLOSTRETRANSMIT);
-                                }
-                        }
-                }
-        }
+        if (lost_retrans && icsk->icsk_ca_state == TCP_CA_Recovery)
+                flag |= tcp_mark_lost_retrans(sk, lost_retrans);
 
         tcp_verify_left_out(tp);