Commit b7e445a1 authored by David S. Miller's avatar David S. Miller

Merge branch 'tcp-RACK-loss-recovery-bug-fixes'

Yuchung Cheng says:

====================
tcp: RACK loss recovery bug fixes

This patch set has four minor bug fixes in TCP RACK loss recovery.
====================
Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
parents 2edbdb31 6065fd0d
......@@ -2329,6 +2329,7 @@ static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss)
}
tp->snd_cwnd_stamp = tcp_jiffies32;
tp->undo_marker = 0;
tp->rack.advanced = 1; /* Force RACK to re-exam losses */
}
static inline bool tcp_may_undo(const struct tcp_sock *tp)
......
......@@ -55,7 +55,8 @@ static void tcp_rack_detect_loss(struct sock *sk, u32 *reo_timeout)
* to queuing or delayed ACKs.
*/
reo_wnd = 1000;
if ((tp->rack.reord || !tp->lost_out) && min_rtt != ~0U) {
if ((tp->rack.reord || inet_csk(sk)->icsk_ca_state < TCP_CA_Recovery) &&
min_rtt != ~0U) {
reo_wnd = max((min_rtt >> 2) * tp->rack.reo_wnd_steps, reo_wnd);
reo_wnd = min(reo_wnd, tp->srtt_us >> 3);
}
......@@ -79,12 +80,12 @@ static void tcp_rack_detect_loss(struct sock *sk, u32 *reo_timeout)
*/
remaining = tp->rack.rtt_us + reo_wnd -
tcp_stamp_us_delta(tp->tcp_mstamp, skb->skb_mstamp);
if (remaining < 0) {
if (remaining <= 0) {
tcp_rack_mark_skb_lost(sk, skb);
list_del_init(&skb->tcp_tsorted_anchor);
} else {
/* Record maximum wait time (+1 to avoid 0) */
*reo_timeout = max_t(u32, *reo_timeout, 1 + remaining);
/* Record maximum wait time */
*reo_timeout = max_t(u32, *reo_timeout, remaining);
}
}
}
......@@ -116,13 +117,8 @@ void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq,
{
u32 rtt_us;
if (tp->rack.mstamp &&
!tcp_rack_sent_after(xmit_time, tp->rack.mstamp,
end_seq, tp->rack.end_seq))
return;
rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, xmit_time);
if (sacked & TCPCB_RETRANS) {
if (rtt_us < tcp_min_rtt(tp) && (sacked & TCPCB_RETRANS)) {
/* If the sacked packet was retransmitted, it's ambiguous
* whether the retransmission or the original (or the prior
* retransmission) was sacked.
......@@ -133,13 +129,15 @@ void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq,
* so it's at least one RTT (i.e., retransmission is at least
* an RTT later).
*/
if (rtt_us < tcp_min_rtt(tp))
return;
return;
}
tp->rack.rtt_us = rtt_us;
tp->rack.mstamp = xmit_time;
tp->rack.end_seq = end_seq;
tp->rack.advanced = 1;
tp->rack.rtt_us = rtt_us;
if (tcp_rack_sent_after(xmit_time, tp->rack.mstamp,
end_seq, tp->rack.end_seq)) {
tp->rack.mstamp = xmit_time;
tp->rack.end_seq = end_seq;
}
}
/* We have waited long enough to accommodate reordering. Mark the expired
......
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