From: Eric Dumazet <dada1@cosmosbay•com>
To: Stephen Hemminger <shemminger@vyatta•com>
Cc: Herbert Xu <herbert@gondor•apana.org.au>,
Evgeniy Polyakov <zbr@ioremap•net>,
berrange@redhat•com, et-mgmt-tools@redhat•com,
davem@davemloft•net, netdev@vger•kernel.org
Subject: Re: virt-manager broken by bind(0) in net-next.
Date: Fri, 30 Jan 2009 19:41:59 +0100 [thread overview]
Message-ID: <498349F7.4050300@cosmosbay.com> (raw)
In-Reply-To: <20090130095737.103edbff@extreme>
Stephen Hemminger a écrit :
> On Fri, 30 Jan 2009 23:53:37 +1100
> Herbert Xu <herbert@gondor•apana.org.au> wrote:
>
>> Evgeniy Polyakov <zbr@ioremap•net> wrote:
>>> So it is not explicit bind call, but port autoselection in the
>>> connect(). Can you check what errno is returned?
>>> Did I understand it right, that connect fails, you try different
>>> address, but then suddenly all those sockets become 'alive'?
>> Yes, I think a good strace vs. a bad strace would be really helpful
>> in these cases.
>>
>> Thanks,
>
> I have the strace but it comes up no different.
> What is different is that in the broken case (net-next), I see
> IPV6 being used:
>
> State Recv-Q Send-Q Local Address:Port Peer Address:Port
> ESTAB 23769 0 ::ffff:127.0.0.1:5900 ::ffff:127.0.0.1:55987
> ESTAB 0 0 127.0.0.1:55987 127.0.0.1:5900
>
> and in the working case (2.6.29-rc3), IPV4 is being used
> State Recv-Q Send-Q Local Address:Port Peer Address:Port
> ESTAB 0 0 127.0.0.1:58894 127.0.0.1:5901
> ESTAB 0 0 127.0.0.1:5901 127.0.0.1:58894
>
Reviewing commit a9d8f9110d7e953c2f2b521087a4179677843c2a
I see use of a hashinfo->bsockets field that :
- lacks proper lock/synchronization
- suffers from cache line ping pongs on SMP
Also there might be a problem at line 175
if (sk->sk_reuse && sk->sk_state != TCP_LISTEN && --attempts >= 0) {
spin_unlock(&head->lock);
goto again;
If we entered inet_csk_get_port() with a non null snum, we can "goto again"
while it was not expected.
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index df8e72f..752c6b2 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -172,7 +172,8 @@ tb_found:
} else {
ret = 1;
if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
- if (sk->sk_reuse && sk->sk_state != TCP_LISTEN && --attempts >= 0) {
+ if (sk->sk_reuse && sk->sk_state != TCP_LISTEN &&
+ smallest_size == -1 && --attempts >= 0) {
spin_unlock(&head->lock);
goto again;
}
next prev parent reply other threads:[~2009-01-30 18:43 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20090128212114.38be3e8c@extreme>
[not found] ` <20090129103544.GC22110@redhat.com>
2009-01-30 5:35 ` virt-manager broken by bind(0) in net-next Stephen Hemminger
2009-01-30 8:16 ` Evgeniy Polyakov
[not found] ` <20090130081600.GA2717-i6C2adt8DTjR7s880joybQ@public.gmane.org>
2009-01-30 10:27 ` Daniel P. Berrange
2009-01-30 11:21 ` Evgeniy Polyakov
2009-01-30 12:53 ` Herbert Xu
[not found] ` <20090130125337.GA7155-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2009-01-30 17:57 ` Stephen Hemminger
2009-01-30 18:41 ` Eric Dumazet [this message]
2009-01-30 21:50 ` Evgeniy Polyakov
2009-01-30 22:30 ` Eric Dumazet
2009-01-30 22:51 ` Evgeniy Polyakov
[not found] ` <20090130225113.GA13977-i6C2adt8DTjR7s880joybQ@public.gmane.org>
2009-01-31 0:36 ` Stephen Hemminger
2009-01-31 8:35 ` Evgeniy Polyakov
2009-01-31 2:52 ` Stephen Hemminger
2009-01-31 8:37 ` Evgeniy Polyakov
2009-01-31 9:17 ` Eric Dumazet
2009-01-31 9:31 ` Evgeniy Polyakov
2009-01-31 9:49 ` Eric Dumazet
2009-01-31 9:56 ` Evgeniy Polyakov
2009-01-31 10:17 ` Eric Dumazet
2009-02-01 12:42 ` Evgeniy Polyakov
2009-02-01 16:12 ` Eric Dumazet
2009-02-01 17:40 ` Evgeniy Polyakov
2009-02-01 20:31 ` David Miller
[not found] ` <20090130215008.GB12210-i6C2adt8DTjR7s880joybQ@public.gmane.org>
2009-02-01 5:58 ` Stephen Hemminger
2009-02-01 9:07 ` David Miller
2009-02-01 12:44 ` Evgeniy Polyakov
[not found] ` <498349F7.4050300-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2009-02-01 5:29 ` Stephen Hemminger
2009-01-30 6:50 ` Stephen Hemminger
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