[TCP]: Extracted rexmit hint clearing from the LOST marking code

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 813f2049b85d911f33d8885aa42f9f671179c32c..7d843c42938154924aa6521c60df83d8a280ba42 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1765,6 +1765,20 @@ static inline void tcp_reset_reno_sack(struct tcp_sock *tp)
        tp->left_out = tp->lost_out;
 }
 
+/* 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 = skb;
+}
+
 /* Mark head of queue up as lost. */
 static void tcp_mark_head_lost(struct sock *sk,
                               int packets, u32 high_seq)
@@ -1795,14 +1809,7 @@ static void tcp_mark_head_lost(struct sock *sk,
                if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
                        TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                        tp->lost_out += tcp_skb_pcount(skb);
-
-                       /* clear xmit_retransmit_queue hints
-                        *  if this is beyond hint */
-                       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;
-
+                       tcp_verify_retransmit_hint(tp, skb);
                }
        }
        tcp_sync_left_out(tp);
@@ -1843,13 +1850,7 @@ static void tcp_update_scoreboard(struct sock *sk)
                        if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) {
                                TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
                                tp->lost_out += tcp_skb_pcount(skb);
-
-                               /* clear xmit_retrans hint */
-                               if (tp->retransmit_skb_hint &&
-                                   before(TCP_SKB_CB(skb)->seq,
-                                          TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
-
-                                       tp->retransmit_skb_hint = NULL;
+                               tcp_verify_retransmit_hint(tp, skb);
                        }
                }