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In-Reply-To: <63316ba7-f612-af5a-3f33-125cf89de754@collabora.com>
From:   Eric Dumazet <edumazet@google.com>
Date:   Mon, 27 Jun 2022 13:47:25 +0200
Message-ID: <CANn89iK96naKmc5Ep1PBxvksShQk=WMEoY_V0qZneN_JAEgtRg@mail.gmail.com>
Subject: Re: [RFC] EADDRINUSE from bind() on application restart after killing
To:     Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Gabriel Krisman Bertazi <krisman@collabora.com>,
        open list <linux-kernel@vger.kernel.org>,
        Collabora Kernel ML <kernel@collabora.com>,
        Paul Gofman <pgofman@codeweavers.com>,
        "open list:NETWORKING [TCP]" <netdev@vger.kernel.org>,
        Sami Farin <hvtaifwkbgefbaei@gmail.com>
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On Mon, Jun 27, 2022 at 12:20 PM Muhammad Usama Anjum
<usama.anjum@collabora.com> wrote:
>
> Hi Eric,
>
> On 5/30/22 8:28 PM, Eric Dumazet wrote:
> >> The following command and patch work for my use case. The socket in
> >> TIME_WAIT_2 or TIME_WAIT state are closed when zapped.
> >>
> >> Can you please upstream this patch?
> > Yes, I will when net-next reopens, thanks for testing it.
> Have you tried upstreaming it?
>
> Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
>

I will do this today, thanks for the heads up.


> >
> >>> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> >>> index 9984d23a7f3e1353d2e1fc9053d98c77268c577e..1b7bde889096aa800b2994c64a3a68edf3b62434
> >>> 100644
> >>> --- a/net/ipv4/tcp.c
> >>> +++ b/net/ipv4/tcp.c
> >>> @@ -4519,6 +4519,15 @@ int tcp_abort(struct sock *sk, int err)
> >>>                         local_bh_enable();
> >>>                         return 0;
> >>>                 }
> >>> +               if (sk->sk_state == TCP_TIME_WAIT) {
> >>> +                       struct inet_timewait_sock *tw = inet_twsk(sk);
> >>> +
> >>> +                       refcount_inc(&tw->tw_refcnt);
> >>> +                       local_bh_disable();
> >>> +                       inet_twsk_deschedule_put(tw);
> >>> +                       local_bh_enable();
> >>> +                       return 0;
> >>> +               }
> >>>                 return -EOPNOTSUPP;
> >>>         }
>
> --
> Muhammad Usama Anjum