Patch "tcp: fix incorrect ca_state in tail loss probe" has been added to the 3.10-stable tree

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This is a note to let you know that I've just added the patch titled

    tcp: fix incorrect ca_state in tail loss probe

to the 3.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tcp-fix-incorrect-ca_state-in-tail-loss-probe.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 81f50cf8065f81d67e2f771f334cb47873415f0b Mon Sep 17 00:00:00 2001
From: Yuchung Cheng <ycheng@xxxxxxxxxx>
Date: Sat, 12 Oct 2013 10:16:27 -0700
Subject: tcp: fix incorrect ca_state in tail loss probe

From: Yuchung Cheng <ycheng@xxxxxxxxxx>

[ Upstream commit 031afe4990a7c9dbff41a3a742c44d3e740ea0a1 ]

On receiving an ACK that covers the loss probe sequence, TLP
immediately sets the congestion state to Open, even though some packets
are not recovered and retransmisssion are on the way.  The later ACks
may trigger a WARN_ON check in step D of tcp_fastretrans_alert(), e.g.,
https://bugzilla.redhat.com/show_bug.cgi?id=989251

The fix is to follow the similar procedure in recovery by calling
tcp_try_keep_open(). The sender switches to Open state if no packets
are retransmissted. Otherwise it goes to Disorder and let subsequent
ACKs move the state to Recovery or Open.

Reported-By: Michael Sterrett <michael@xxxxxxxxxxxxx>
Tested-By: Dormando <dormando@xxxxxxxxx>
Signed-off-by: Yuchung Cheng <ycheng@xxxxxxxxxx>
Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/ipv4/tcp_input.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3345,7 +3345,7 @@ static void tcp_process_tlp_ack(struct s
 			tcp_init_cwnd_reduction(sk, true);
 			tcp_set_ca_state(sk, TCP_CA_CWR);
 			tcp_end_cwnd_reduction(sk);
-			tcp_set_ca_state(sk, TCP_CA_Open);
+			tcp_try_keep_open(sk);
 			NET_INC_STATS_BH(sock_net(sk),
 					 LINUX_MIB_TCPLOSSPROBERECOVERY);
 		}


Patches currently in stable-queue which might be from ycheng@xxxxxxxxxx are

queue-3.10/tcp-tsq-can-use-a-dynamic-limit.patch
queue-3.10/tcp-must-unclone-packets-before-mangling-them.patch
queue-3.10/tcp-fix-incorrect-ca_state-in-tail-loss-probe.patch
queue-3.10/tcp-do-not-forget-fin-in-tcp_shifted_skb.patch
queue-3.10/tcp-tso-packets-automatic-sizing.patch
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