| Message ID | 1352988197-14414-1-git-send-email-avagin@openvz.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 11/15/2012 06:03 PM, Andrey Vagin wrote: > From: Andrew Vagin <avagin@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@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> > Signed-off-by: Andrey Vagin <avagin@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2012-11-15 at 18:03 +0400, Andrey Vagin wrote: > From: Andrew Vagin <avagin@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@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> > Signed-off-by: Andrey Vagin <avagin@openvz.org> Any chance these tcp repair hacks could be done outside of tcp fast path ? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Pavel Emelyanov <xemul@parallels.com> Date: Thu, 15 Nov 2012 18:10:59 +0400 > On 11/15/2012 06:03 PM, Andrey Vagin wrote: >> From: Andrew Vagin <avagin@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. ... >> Signed-off-by: Andrey Vagin <avagin@openvz.org> > > Acked-by: Pavel Emelyanov <xemul@parallels.com> Applied and queued up for -stable, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 197c000..083092e 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1212,7 +1212,7 @@ new_segment: wait_for_sndbuf: set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); wait_for_memory: - if (copied && likely(!tp->repair)) + if (copied) tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) @@ -1223,7 +1223,7 @@ wait_for_memory: } out: - if (copied && likely(!tp->repair)) + if (copied) tcp_push(sk, flags, mss_now, tp->nonagle); release_sock(sk); return copied + copied_syn; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index cfe6ffe..2798706 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1986,6 +1986,9 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, tso_segs = tcp_init_tso_segs(sk, skb, mss_now); BUG_ON(!tso_segs); + if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) + goto repair; /* Skip network transmission */ + cwnd_quota = tcp_cwnd_test(tp, skb); if (!cwnd_quota) break; @@ -2026,6 +2029,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp))) break; +repair: /* Advance the send_head. This one is sent out. * This call will increment packets_out. */