[PATCH 3.14 31/37] tcp: fixing TLPs FIN recovery

From: Greg Kroah-Hartman
Date: Sun Oct 12 2014 - 22:51:23 EST

3.14-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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/ipv4/tcp_output.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2069,9 +2069,7 @@ 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))

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