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From:   Cong Wang <xiyou.wangcong@gmail.com>
Date:   Tue, 27 Jul 2021 19:07:43 -0700
Message-ID: <CAM_iQpVedTzRbf-bC7WuGMFYF=qnUxbnUdqJ9+FaxrTAn5DkTw@mail.gmail.com>
Subject: Re: [PATCH bpf-next v1 2/5] af_unix: add unix_stream_proto for sockmap
To:     John Fastabend <john.fastabend@gmail.com>
Cc:     Jiang Wang <jiang.wang@bytedance.com>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        "Cong Wang ." <cong.wang@bytedance.com>,
        Xiongchun Duan <duanxiongchun@bytedance.com>,
        xieyongji@bytedance.com, chaiwen.cc@bytedance.com,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jakub Sitnicki <jakub@cloudflare.com>,
        Lorenz Bauer <lmb@cloudflare.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
        Johan Almbladh <johan.almbladh@anyfinetworks.com>,
        linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
        linux-kselftest@vger.kernel.org
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On Tue, Jul 27, 2021 at 9:37 AM John Fastabend <john.fastabend@gmail.com> wrote:
> Do we really need an unhash hook for unix_stream? I'm doing some testing
> now to pull it out of TCP side as well. It seems to be an artifact of old
> code that is no longer necessary. On TCP side at least just using close()
> looks to be enough now.

How do you handle the disconnection from remote without ->unhash()?

For all stream sockets, we still only allow established sockets to stay
in sockmap, which means we have to remove it if it is disconnected
or closed.

But it seems Jiang forgot to call ->unhash() when disconnecting.

Thanks.