tcp: fix retransmission in repair mode
authorAndrew Vagin <avagin@openvz.org>
Thu, 15 Nov 2012 04:03:17 +0000 (04:03 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 26 Nov 2012 20:14:19 +0000 (12:14 -0800)
commitc6f7b86211233142300aeec7b1ab4ae640b81abd
tree5b8f0580777fc714b9dd1597ee1bac61da701011
parenta809dffbbbcfbac5f6e6e291e472ac3ca91e0ca2
tcp: fix retransmission in repair mode

[ Upstream commit ec34232575083fd0f43d3a101e8ebb041b203761 ]

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.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/ipv4/tcp.c
net/ipv4/tcp_output.c