[TCP]: Restore 2.6.24 mark_head_lost behavior for newreno/fack
The fast retransmission can be forced locally to the rfc3517
branch in tcp_update_scoreboard instead of making such fragile
constructs deeper in tcp_mark_head_lost.
This is necessary for the next patch which must not have
loopholes for cnt > packets check. As one can notice,
readability got some improvements too because of this :-).
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 7facdb0..5573202 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2134,7 +2134,7 @@
/* Mark head of queue up as lost. With RFC3517 SACK, the packets is
* is against sacked "cnt", otherwise it's against facked "cnt"
*/
-static void tcp_mark_head_lost(struct sock *sk, int packets, int fast_rexmit)
+static void tcp_mark_head_lost(struct sock *sk, int packets)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
@@ -2161,7 +2161,7 @@
(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
cnt += tcp_skb_pcount(skb);
- if (((!fast_rexmit || (tp->lost_out > 0)) && (cnt > packets)) ||
+ if ((cnt > packets) ||
after(TCP_SKB_CB(skb)->end_seq, tp->high_seq))
break;
if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_SACKED_ACKED|TCPCB_LOST))) {
@@ -2180,17 +2180,17 @@
struct tcp_sock *tp = tcp_sk(sk);
if (tcp_is_reno(tp)) {
- tcp_mark_head_lost(sk, 1, fast_rexmit);
+ tcp_mark_head_lost(sk, 1);
} else if (tcp_is_fack(tp)) {
int lost = tp->fackets_out - tp->reordering;
if (lost <= 0)
lost = 1;
- tcp_mark_head_lost(sk, lost, fast_rexmit);
+ tcp_mark_head_lost(sk, lost);
} else {
int sacked_upto = tp->sacked_out - tp->reordering;
- if (sacked_upto < 0)
- sacked_upto = 0;
- tcp_mark_head_lost(sk, sacked_upto, fast_rexmit);
+ if (sacked_upto < fast_rexmit)
+ sacked_upto = fast_rexmit;
+ tcp_mark_head_lost(sk, sacked_upto);
}
/* New heuristics: it is possible only after we switched
@@ -2524,7 +2524,7 @@
before(tp->snd_una, tp->high_seq) &&
icsk->icsk_ca_state != TCP_CA_Open &&
tp->fackets_out > tp->reordering) {
- tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering, 0);
+ tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering);
NET_INC_STATS_BH(LINUX_MIB_TCPLOSS);
}