tcp: sack lost marking fixes

When only fast rexmit should be done, tcp_mark_head_lost marks
L too far. Also, sacked_upto below 1 is perfectly valid number,
the packets == 0 then needs to be trapped elsewhere.

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 2010-10-14 01:42:30 +00:00 committed by David S. Miller
parent f3e85df845
commit 1fdb936101

View File

@ -2495,7 +2495,7 @@ static void tcp_timeout_skbs(struct sock *sk)
/* 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)
static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
@ -2503,13 +2503,13 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
int err;
unsigned int mss;
if (packets == 0)
return;
WARN_ON(packets > tp->packets_out);
if (tp->lost_skb_hint) {
skb = tp->lost_skb_hint;
cnt = tp->lost_cnt_hint;
/* Head already handled? */
if (mark_head && skb != tcp_write_queue_head(sk))
return;
} else {
skb = tcp_write_queue_head(sk);
cnt = 0;
@ -2544,6 +2544,9 @@ static void tcp_mark_head_lost(struct sock *sk, int packets)
}
tcp_skb_mark_lost(tp, skb);
if (mark_head)
break;
}
tcp_verify_left_out(tp);
}
@ -2555,17 +2558,18 @@ 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);
tcp_mark_head_lost(sk, 1, 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);
tcp_mark_head_lost(sk, lost, 0);
} else {
int sacked_upto = tp->sacked_out - tp->reordering;
if (sacked_upto < fast_rexmit)
sacked_upto = fast_rexmit;
tcp_mark_head_lost(sk, sacked_upto);
if (sacked_upto >= 0)
tcp_mark_head_lost(sk, sacked_upto, 0);
else if (fast_rexmit)
tcp_mark_head_lost(sk, 1, 1);
}
tcp_timeout_skbs(sk);
@ -2971,7 +2975,7 @@ 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);
tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering, 0);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSS);
}