Re: [tipc-discussion] [PATCH net v1 1/2] tipc: fix socket flow control errors

[Parthasarathy B. <par...@er...>]

Please ignore this patch and
'tipc: Fix missing connection request handling'.

They dont belong to this series and they are not the right version.

/Partha

On 03/13/2017 06:57 PM, Parthasarathy Bhuvaragan wrote:
> In this commit, we fix the following two errors:
> 1. In tipc_send_stream(), fix the return value during congestion
>    when the send is partially successful. Until now, we return -1
>    instead of returning the partial sent bytes.
> 2. In tipc_recv_stream(), we update the rcv_unack not based on the
>    message size, but on sz. Usually they are the same, but in cases
>    where the socket receivers buffer is smaller than the incoming
>    message, these two parameters differ greatly. This introduces a
>    slack in accounting leading to permanent congestion. In this
>    commit, we perform accounting always based on the incoming message.
>
> Signed-off-by: Parthasarathy Bhuvaragan <par...@er...>
> ---
>  net/tipc/socket.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/net/tipc/socket.c b/net/tipc/socket.c
> index 6b09a778cc71..79e628cd08a9 100644
> --- a/net/tipc/socket.c
> +++ b/net/tipc/socket.c
> @@ -1080,7 +1080,7 @@ static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dlen)
>  		}
>  	} while (sent < dlen && !rc);
>
> -	return rc ? rc : sent;
> +	return sent ? sent : rc;
>  }
>
>  /**
> @@ -1481,16 +1481,15 @@ static int tipc_recv_stream(struct socket *sock, struct msghdr *m,
>  	if (unlikely(flags & MSG_PEEK))
>  		goto exit;
>
> -	tsk->rcv_unacked += tsk_inc(tsk, hlen + sz);
> +	tsk->rcv_unacked += tsk_inc(tsk, hlen + msg_data_sz(msg));
>  	if (unlikely(tsk->rcv_unacked >= (tsk->rcv_win / 4)))
>  		tipc_sk_send_ack(tsk);
>  	tsk_advance_rx_queue(sk);
>
>  	/* Loop around if more data is required */
> -	if ((sz_copied < buf_len) &&	/* didn't get all requested data */
> +	if ((!err) && (sz_copied < buf_len) &&
>  	    (!skb_queue_empty(&sk->sk_receive_queue) ||
> -	    (sz_copied < target)) &&	/* and more is ready or required */
> -	    (!err))			/* and haven't reached a FIN */
> +	     (sz_copied < target)))
>  		goto restart;
>
>  exit:
>