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 <>
Reviewed-by: 's avatarNeal Cardwell <>
Reviewed-by: 's avatarPriyaranjan Jha <>
Reviewed-by: 's avatarEric Dumazet <>
Signed-off-by: 's avatarDavid S. Miller <>
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);
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment