[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>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index bac17c5..34acee6 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -332,8 +332,10 @@
struct tcp_sack_block_wire recv_sack_cache[4];
- u32 highest_sack; /* Start seq of globally highest revd SACK
- * (validity guaranteed only if sacked_out > 0) */
+ struct sk_buff *highest_sack; /* highest skb with SACK received
+ * (validity guaranteed only if
+ * sacked_out > 0)
+ */
/* from STCP, retrans queue hinting */
struct sk_buff* lost_skb_hint;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index d893b44..0ede804 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1312,6 +1312,16 @@
return skb_queue_empty(&sk->sk_write_queue);
}
+/* Start sequence of the highest skb with SACKed bit, valid only if
+ * sacked > 0 or when the caller has ensured validity by itself.
+ */
+static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp)
+{
+ if (!tp->sacked_out)
+ return tp->snd_una;
+ return TCP_SKB_CB(tp->highest_sack)->seq;
+}
+
/* /proc */
enum tcp_seq_states {
TCP_SEQ_STATE_LISTENING,
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c0e8f2b..31294b5 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1245,7 +1245,7 @@
int num_sacks = (ptr[1] - TCPOLEN_SACK_BASE)>>3;
int reord = tp->packets_out;
int prior_fackets;
- u32 highest_sack_end_seq = tp->lost_retrans_low;
+ u32 highest_sack_end_seq;
int flag = 0;
int found_dup_sack = 0;
int cached_fack_count;
@@ -1256,7 +1256,7 @@
if (!tp->sacked_out) {
if (WARN_ON(tp->fackets_out))
tp->fackets_out = 0;
- tp->highest_sack = tp->snd_una;
+ tp->highest_sack = tcp_write_queue_head(sk);
}
prior_fackets = tp->fackets_out;
@@ -1483,10 +1483,9 @@
if (fack_count > tp->fackets_out)
tp->fackets_out = fack_count;
- if (after(TCP_SKB_CB(skb)->seq, tp->highest_sack)) {
- tp->highest_sack = TCP_SKB_CB(skb)->seq;
- highest_sack_end_seq = TCP_SKB_CB(skb)->end_seq;
- }
+ if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+ tp->highest_sack = skb;
+
} else {
if (dup_sack && (sacked&TCPCB_RETRANS))
reord = min(fack_count, reord);
@@ -1514,6 +1513,7 @@
flag &= ~FLAG_ONLY_ORIG_SACKED;
}
+ highest_sack_end_seq = TCP_SKB_CB(tp->highest_sack)->end_seq;
if (tcp_is_fack(tp) && tp->retrans_out &&
after(highest_sack_end_seq, tp->lost_retrans_low) &&
icsk->icsk_ca_state == TCP_CA_Recovery)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f4c1eef..ce506af 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -657,13 +657,15 @@
* 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 @@
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 @@
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 @@
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 @@
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 @@
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)