[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>

1 files changed, 16 insertions, 15 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 813f2049b85d..7d843c429381 100644
--- 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);
                         }
                 }