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

[Pavel Emelyanov]

On 11/15/2012 06:03 PM, Andrey Vagin wrote:
> From: Andrew Vagin <avagin at openvz.org>
> 
> 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 at parallels.com>
> Cc: "David S. Miller" <davem at davemloft.net>
> Cc: Alexey Kuznetsov <kuznet at ms2.inr.ac.ru>
> Cc: James Morris <jmorris at namei.org>
> Cc: Hideaki YOSHIFUJI <yoshfuji at linux-ipv6.org>
> Cc: Patrick McHardy <kaber at trash.net>
> Signed-off-by: Andrey Vagin <avagin at openvz.org>

Acked-by: Pavel Emelyanov <xemul at parallels.com>