Commit 0ce294d8 authored by Yuchung Cheng's avatar Yuchung Cheng Committed by David S. Miller

tcp: correctly test congestion state in RACK

RACK does not test the loss recovery state correctly to compute
the reordering window. It assumes if lost_out is zero then TCP is
not in loss recovery. But it can be zero during recovery before
calling tcp_rack_detect_loss(): when an ACK acknowledges all
packets marked lost before receiving this ACK, but has not yet
to discover new ones by tcp_rack_detect_loss(). The fix is to
simply test the congestion state directly.
Signed-off-by: 's avatarYuchung Cheng <ycheng@google.com>
Reviewed-by: 's avatarNeal Cardwell <ncardwell@google.com>
Reviewed-by: 's avatarPriyaranjan Jha <priyarjha@google.com>
Reviewed-by: 's avatarEric Dumazet <edumazet@google.com>
Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
parent 2edbdb31
......@@ -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);
}
......
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