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* [PATCH] tcp: fix regression in urgent data handling
@ 2012-09-17 22:51 Eric Dumazet
  2012-09-18  7:54 ` [PATCH v2] " Eric Dumazet
  2012-09-18 20:26 ` [PATCH] " David Miller
  0 siblings, 2 replies; 4+ messages in thread
From: Eric Dumazet @ 2012-09-17 22:51 UTC (permalink / raw)
  To: David Miller; +Cc: netdev, Stephan Springl, Alexander Duyck

From: Eric Dumazet <edumazet@google.com>

Stephan Springl found that commit 1402d366019fed "tcp: introduce
tcp_try_coalesce" introduced a regression for rlogin

It turns out problem comes from TCP urgent data handling and
a change in behavior in input path.

rlogin sends two one-byte packets with URG ptr set, and when next data
frame is coalesced, we lack sk_data_ready() calls to wakeup consumer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stephan Springl <springl-k@lar.bfw.de>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/ipv4/tcp_input.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6e38c6c..d377f48 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4661,7 +4661,7 @@ queue_and_out:
 
 		if (eaten > 0)
 			kfree_skb_partial(skb, fragstolen);
-		else if (!sock_flag(sk, SOCK_DEAD))
+		if (!sock_flag(sk, SOCK_DEAD))
 			sk->sk_data_ready(sk, 0);
 		return;
 	}
@@ -5556,8 +5556,7 @@ no_ack:
 #endif
 			if (eaten)
 				kfree_skb_partial(skb, fragstolen);
-			else
-				sk->sk_data_ready(sk, 0);
+			sk->sk_data_ready(sk, 0);
 			return 0;
 		}
 	}

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH v2] tcp: fix regression in urgent data handling
  2012-09-17 22:51 [PATCH] tcp: fix regression in urgent data handling Eric Dumazet
@ 2012-09-18  7:54 ` Eric Dumazet
  2012-09-18  8:00   ` Stephan Springl
  2012-09-18 20:26 ` [PATCH] " David Miller
  1 sibling, 1 reply; 4+ messages in thread
From: Eric Dumazet @ 2012-09-18  7:54 UTC (permalink / raw)
  To: David Miller; +Cc: netdev, Stephan Springl, Alexander Duyck

From: Eric Dumazet <edumazet@google.com>

Stephan Springl found that commit 1402d366019fed "tcp: introduce
tcp_try_coalesce" introduced a regression for rlogin

It turns out problem comes from TCP urgent data handling and
a change in behavior in input path.

rlogin sends two one-byte packets with URG ptr set, and when next data
frame is coalesced, we lack sk_data_ready() calls to wakeup consumer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stephan Springl <springl-k@bfw-online.de>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
---
v2: Changed Stephan Springl email address in changelog/CC

 net/ipv4/tcp_input.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 6e38c6c..d377f48 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4661,7 +4661,7 @@ queue_and_out:
 
 		if (eaten > 0)
 			kfree_skb_partial(skb, fragstolen);
-		else if (!sock_flag(sk, SOCK_DEAD))
+		if (!sock_flag(sk, SOCK_DEAD))
 			sk->sk_data_ready(sk, 0);
 		return;
 	}
@@ -5556,8 +5556,7 @@ no_ack:
 #endif
 			if (eaten)
 				kfree_skb_partial(skb, fragstolen);
-			else
-				sk->sk_data_ready(sk, 0);
+			sk->sk_data_ready(sk, 0);
 			return 0;
 		}
 	}

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] tcp: fix regression in urgent data handling
  2012-09-18  7:54 ` [PATCH v2] " Eric Dumazet
@ 2012-09-18  8:00   ` Stephan Springl
  0 siblings, 0 replies; 4+ messages in thread
From: Stephan Springl @ 2012-09-18  8:00 UTC (permalink / raw)
  To: Eric Dumazet; +Cc: David Miller, netdev, Alexander Duyck

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1980 bytes --]

Works here on top of 3.5.4, so

Tested-by: Stephan Springl <springl-k@bfw-online.de>

On Tue, 18 Sep 2012, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> Stephan Springl found that commit 1402d366019fed "tcp: introduce
> tcp_try_coalesce" introduced a regression for rlogin
>
> It turns out problem comes from TCP urgent data handling and
> a change in behavior in input path.
>
> rlogin sends two one-byte packets with URG ptr set, and when next data
> frame is coalesced, we lack sk_data_ready() calls to wakeup consumer.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Stephan Springl <springl-k@bfw-online.de>
> Cc: Alexander Duyck <alexander.h.duyck@intel.com>
> ---
> v2: Changed Stephan Springl email address in changelog/CC
>
> net/ipv4/tcp_input.c |    5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index 6e38c6c..d377f48 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -4661,7 +4661,7 @@ queue_and_out:
>
> 		if (eaten > 0)
> 			kfree_skb_partial(skb, fragstolen);
> -		else if (!sock_flag(sk, SOCK_DEAD))
> +		if (!sock_flag(sk, SOCK_DEAD))
> 			sk->sk_data_ready(sk, 0);
> 		return;
> 	}
> @@ -5556,8 +5556,7 @@ no_ack:
> #endif
> 			if (eaten)
> 				kfree_skb_partial(skb, fragstolen);
> -			else
> -				sk->sk_data_ready(sk, 0);
> +			sk->sk_data_ready(sk, 0);
> 			return 0;
> 		}
> 	}
>
>
>


Freundliche Grüße

BFW Werner Völk GmbH
ppa. Stephan Springl
-- 
Stephan Springl                           BFW Werner Völk GmbH
Tel.:  +49 89 82917-452                   Energiemesstechnik & Service
Fax:   +49 89 82917-599                   Pasinger Str. 20 - 22
Mail:  springl@bfw-online.de              D-82166 Gräfelfing
Web:   http://www.novamess.de             Geschäftsführer: Georg F. Völk
                                           HRB 44779 Amtsgericht München
                                           USt.-ID: DE129301566

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] tcp: fix regression in urgent data handling
  2012-09-17 22:51 [PATCH] tcp: fix regression in urgent data handling Eric Dumazet
  2012-09-18  7:54 ` [PATCH v2] " Eric Dumazet
@ 2012-09-18 20:26 ` David Miller
  1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2012-09-18 20:26 UTC (permalink / raw)
  To: eric.dumazet; +Cc: netdev, springl-k, alexander.h.duyck

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 18 Sep 2012 00:51:39 +0200

> From: Eric Dumazet <edumazet@google.com>
> 
> Stephan Springl found that commit 1402d366019fed "tcp: introduce
> tcp_try_coalesce" introduced a regression for rlogin
> 
> It turns out problem comes from TCP urgent data handling and
> a change in behavior in input path.
> 
> rlogin sends two one-byte packets with URG ptr set, and when next data
> frame is coalesced, we lack sk_data_ready() calls to wakeup consumer.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Stephan Springl <springl-k@lar.bfw.de>
> Cc: Alexander Duyck <alexander.h.duyck@intel.com>

Applied, thanks Eric.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2012-09-18 20:26 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-09-17 22:51 [PATCH] tcp: fix regression in urgent data handling Eric Dumazet
2012-09-18  7:54 ` [PATCH v2] " Eric Dumazet
2012-09-18  8:00   ` Stephan Springl
2012-09-18 20:26 ` [PATCH] " David Miller

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