Re: [PATCH net-next 1/2] vsock: fold sk_acceptq_added() into vsock_enqueue_accept()

[Bobby Eshleman <bobbyeshleman@gmail.com>]

On Wed, Jun 10, 2026 at 09:11:20AM +0000, Raf Dickson wrote:
> All three transports (vmci, virtio, hyperv) call sk_acceptq_added()
> immediately before vsock_enqueue_accept(). Move the call into
> vsock_enqueue_accept() itself so callers cannot forget it and the
> accounting is always consistent.
> 
> Suggested-by: Paolo Abeni <pabeni@redhat.com>
> Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
> 
> Signed-off-by: Raf Dickson <rafdog35@gmail.com>
> ---
>  net/vmw_vsock/af_vsock.c                | 1 +
>  net/vmw_vsock/hyperv_transport.c        | 1 -
>  net/vmw_vsock/virtio_transport_common.c | 1 -
>  net/vmw_vsock/vmci_transport.c          | 1 -
>  4 files changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 2ce1063d4a..73e6416ee9 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -507,6 +507,7 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
>  	sock_hold(connected);
>  	sock_hold(listener);
>  	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
> +	sk_acceptq_added(listener);
>  }
>  EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
>  
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index b3394946b2..0de8148877 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -410,7 +410,6 @@ static void hvs_open_connection(struct vmbus_channel *chan)
>  
>  	if (conn_from_host) {
>  		new->sk_state = TCP_ESTABLISHED;
> -		sk_acceptq_added(sk);
>  
>  		hvs_new->vm_srv_id = *if_type;
>  		hvs_new->host_srv_id = *if_instance;
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index b10666937c..4a39d48db9 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -1582,7 +1582,6 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
>  		return ret;
>  	}
>  
> -	sk_acceptq_added(sk);
>  	if (virtio_transport_space_update(child, skb))
>  		child->sk_write_space(child);
>  
> diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
> index 91516488a7..4ce6660c11 100644
> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -1109,7 +1109,6 @@ static int vmci_transport_recv_listen(struct sock *sk,
>  	}
>  
>  	vsock_add_pending(sk, pending);
> -	sk_acceptq_added(sk);

It looks like vmci might be an odd duck here, where sk_acceptq_added
actually pairs with vsock_add_pending(), instead of
vsock_enqueue_accept()...

For example, if the pending work timer below fires, vsock_pending_work()
will see vsock_is_pending() is true, and then hit sk_acceptq_removed()
and underflow the zero backlog counter?

Best,
Bobby