[TCP]: Convert highest_sack to sk_buff to allow direct access

It is going to replace the sack fastpath hint quite soon... :-)

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

1 files changed, 10 insertions, 9 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f4c1eef89af0..ce506af5ce07 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -657,13 +657,15 @@ static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned
  * tweak SACK fastpath hint too as it would overwrite all changes unless
  * hint is also changed.
  */
-static void tcp_adjust_fackets_out(struct tcp_sock *tp, struct sk_buff *skb,
+static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb,
                                    int decr)
 {
+        struct tcp_sock *tp = tcp_sk(sk);
+
         if (!tp->sacked_out || tcp_is_reno(tp))
                 return;
 
-        if (!before(tp->highest_sack, TCP_SKB_CB(skb)->seq))
+        if (!before(tcp_highest_sack_seq(tp), TCP_SKB_CB(skb)->seq))
                 tp->fackets_out -= decr;
 
         /* cnt_hint is "off-by-one" compared with fackets_out (see sacktag) */
@@ -712,9 +714,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
         TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq;
         TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
 
-        if (tcp_is_sack(tp) && tp->sacked_out &&
-            (TCP_SKB_CB(skb)->seq == tp->highest_sack))
-                tp->highest_sack = TCP_SKB_CB(buff)->seq;
+        if (tcp_is_sack(tp) && tp->sacked_out && (skb == tp->highest_sack))
+                tp->highest_sack = buff;
 
         /* PSH and FIN should only be set in the second packet. */
         flags = TCP_SKB_CB(skb)->flags;
@@ -772,7 +773,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss
                         tcp_dec_pcount_approx_int(&tp->sacked_out, diff);
                         tcp_verify_left_out(tp);
                 }
-                tcp_adjust_fackets_out(tp, skb, diff);
+                tcp_adjust_fackets_out(sk, skb, diff);
         }
 
         /* Link BUFF into the send queue. */
@@ -1712,7 +1713,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                        tcp_skb_pcount(next_skb) != 1);
 
                 if (WARN_ON(tcp_is_sack(tp) && tp->sacked_out &&
-                    (TCP_SKB_CB(next_skb)->seq == tp->highest_sack)))
+                    (next_skb == tp->highest_sack)))
                         return;
 
                 /* Ok.  We will be able to collapse the packet. */
@@ -1747,7 +1748,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m
                 if (tcp_is_reno(tp) && tp->sacked_out)
                         tcp_dec_pcount_approx(&tp->sacked_out, next_skb);
 
-                tcp_adjust_fackets_out(tp, next_skb, tcp_skb_pcount(next_skb));
+                tcp_adjust_fackets_out(sk, next_skb, tcp_skb_pcount(next_skb));
                 tp->packets_out -= tcp_skb_pcount(next_skb);
 
                 /* changed transmit queue under us so clear hints */
@@ -2028,7 +2029,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
                         break;
                 tp->forward_skb_hint = skb;
 
-                if (after(TCP_SKB_CB(skb)->seq, tp->highest_sack))
+                if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
                         break;
 
                 if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)