Re: [PATCH v2] hv_sock: Add support for delayed close

[David Miller]

From: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
Date: Wed, 15 May 2019 00:56:05 +0000

> Currently, hvsock does not implement any delayed or background close
> logic. Whenever the hvsock socket is closed, a FIN is sent to the peer, and
> the last reference to the socket is dropped, which leads to a call to
> .destruct where the socket can hang indefinitely waiting for the peer to
> close it's side. The can cause the user application to hang in the close()
> call.
> 
> This change implements proper STREAM(TCP) closing handshake mechanism by
> sending the FIN to the peer and the waiting for the peer's FIN to arrive
> for a given timeout. On timeout, it will try to terminate the connection
> (i.e. a RST). This is in-line with other socket providers such as virtio.
> 
> This change does not address the hang in the vmbus_hvsock_device_unregister
> where it waits indefinitely for the host to rescind the channel. That
> should be taken up as a separate fix.
> 
> Signed-off-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>

Applied, thanks.