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| author | Yuchung Cheng <ycheng@google.com> | 2013-03-24 10:42:25 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-04-05 10:04:38 -0700 |
| commit | d1f60c6d91df21978218af4f5442993749ecbf7e (patch) | |
| tree | 9a950b44637f7df25d1c79d50c4820500a3664aa /net | |
| parent | 21b56e0f081f321334ef90d0d4ebe95e79d70a46 (diff) | |
| download | linux-3.10-d1f60c6d91df21978218af4f5442993749ecbf7e.tar.gz linux-3.10-d1f60c6d91df21978218af4f5442993749ecbf7e.tar.bz2 linux-3.10-d1f60c6d91df21978218af4f5442993749ecbf7e.zip | |
tcp: undo spurious timeout after SACK reneging
[ Upstream commit 7ebe183c6d444ef5587d803b64a1f4734b18c564 ]
On SACK reneging the sender immediately retransmits and forces a
timeout but disables Eifel (undo). If the (buggy) receiver does not
drop any packet this can trigger a false slow-start retransmit storm
driven by the ACKs of the original packets. This can be detected with
undo and TCP timestamps.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index fc2fc722a7e..0a1f159f66e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -2260,11 +2260,8 @@ void tcp_enter_loss(struct sock *sk, int how) if (tcp_is_reno(tp)) tcp_reset_reno_sack(tp); - if (!how) { - /* Push undo marker, if it was plain RTO and nothing - * was retransmitted. */ - tp->undo_marker = tp->snd_una; - } else { + tp->undo_marker = tp->snd_una; + if (how) { tp->sacked_out = 0; tp->fackets_out = 0; } |