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Message-ID: <d91ac5f0-1f47-58b3-d033-f492d0e17da7@sberdevices.ru>
Date:   Tue, 28 Mar 2023 12:32:10 +0300
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Subject: Re: [RFC PATCH v2 2/3] virtio/vsock: WARN_ONCE() for invalid state of
 socket
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To:     Stefano Garzarella <sgarzare@redhat.com>
CC:     Stefan Hajnoczi <stefanha@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Bobby Eshleman <bobby.eshleman@bytedance.com>,
        <kvm@vger.kernel.org>, <virtualization@lists.linux-foundation.org>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <kernel@sberdevices.ru>, <oxffffaa@gmail.com>
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 <lgpswwclsuiukh2q5couf33jytf6abneazmwkty6fevoxcgh5p@3dzfbmenjhco>
From:   Arseniy Krasnov <avkrasnov@sberdevices.ru>
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On 28.03.2023 12:29, Stefano Garzarella wrote:
> On Sun, Mar 26, 2023 at 01:09:25AM +0300, Arseniy Krasnov wrote:
>> This adds WARN_ONCE() and return from stream dequeue callback when
>> socket's queue is empty, but 'rx_bytes' still non-zero.
> 
> Nit: I would explain why we add this, for example:
> 
> This allows the detection of potential bugs due to packet merging
> (see previous patch).
> 
>>
>> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
>> ---
>> net/vmw_vsock/virtio_transport_common.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
> 
>>
>> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>> index b9144af71553..ad70531de133 100644
>> --- a/net/vmw_vsock/virtio_transport_common.c
>> +++ b/net/vmw_vsock/virtio_transport_common.c
>> @@ -398,6 +398,13 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
>>     u32 free_space;
>>
>>     spin_lock_bh(&vvs->rx_lock);
>> +
>> +    if (WARN_ONCE(skb_queue_empty(&vvs->rx_queue) && vvs->rx_bytes,
>> +              "No skbuffs with non-zero 'rx_bytes'\n")) {
> 
> Nit: I would rephrase it this way:
> "rx_queue is empty, but rx_bytes is non-zero"
> 
>> +        spin_unlock_bh(&vvs->rx_lock);
>> +        return err;
>> +    }
>> +
>>     while (total < len && !skb_queue_empty(&vvs->rx_queue)) {
>>         skb = skb_peek(&vvs->rx_queue);
>>
>> -- 
>> 2.25.1
>>
> 
> Anyway the patch LGTM!

Thanks for review! Since only string value and commit message should be
updated, i can resend it with 'net' (as it is fix) and update two thing
above in 'net' version?

Thanks, Arseniy
> 
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
>