[PATCH 3.13 027/162] tcp: fixing TLP's FIN recovery

[Kamal Mostafa]

3.13.11.11 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Per Hurtig <per.hurtig@xxxxxx>

[ Upstream commit bef1909ee3ed1ca39231b260a8d3b4544ecd0c8f ]

Fix to a problem observed when losing a FIN segment that does not
contain data.  In such situations, TLP is unable to recover from
*any* tail loss and instead adds at least PTO ms to the
retransmission process, i.e., RTO = RTO + PTO.

Signed-off-by: Per Hurtig <per.hurtig@xxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Nandita Dukkipati <nanditad@xxxxxxxxxx>
Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 net/ipv4/tcp_output.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f587e1c..395f909 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2048,9 +2048,7 @@ void tcp_send_loss_probe(struct sock *sk)
 	if (WARN_ON(!skb || !tcp_skb_pcount(skb)))
 		goto rearm_timer;
 
-	/* Probe with zero data doesn't trigger fast recovery. */
-	if (skb->len > 0)
-		err = __tcp_retransmit_skb(sk, skb);
+	err = __tcp_retransmit_skb(sk, skb);
 
 	/* Record snd_nxt for loss detection. */
 	if (likely(!err))
-- 
1.9.1

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