[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>
This commit is contained in:
Ilpo Järvinen 2008-04-07 22:31:38 -07:00 committed by David S. Miller
parent bfe87dbc7b
commit 1b69d74539

View File

@ -2134,7 +2134,7 @@ static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb)
/* 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 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int fast_rexmit)
(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 @@ static void tcp_update_scoreboard(struct sock *sk, int fast_rexmit)
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 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag)
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);
}