Re: [PATCH] tcp: fix retransmission in repair mode

From: Pavel Emelyanov
Date: Thu Nov 15 2012 - 09:10:51 EST


On 11/15/2012 06:03 PM, Andrey Vagin wrote:
> From: Andrew Vagin <avagin@xxxxxxxxxx>
>
> Currently if a socket was repaired with a few packet in a write queue,
> a kernel bug may be triggered:
>
> kernel BUG at net/ipv4/tcp_output.c:2330!
> RIP: 0010:[<ffffffff8155784f>] tcp_retransmit_skb+0x5ff/0x610
>
> According to the initial realization v3.4-rc2-963-gc0e88ff,
> all skb-s should look like already posted. This patch fixes code
> according with this sentence.
>
> Here are three points, which were not done in the initial patch:
> 1. A tcp send head should not be changed
> 2. Initialize TSO state of a skb
> 3. Reset the retransmission time
>
> This patch moves logic from tcp_sendmsg to tcp_write_xmit. A packet
> passes the ussual way, but isn't sent to network. This patch solves
> all described problems and handles tcp_sendpages.
>
> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx>
> Cc: James Morris <jmorris@xxxxxxxxx>
> Cc: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx>
> Cc: Patrick McHardy <kaber@xxxxxxxxx>
> Signed-off-by: Andrey Vagin <avagin@xxxxxxxxxx>

Acked-by: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
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