[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>

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e8c3948..101054c 100644 (file)
--- 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);