From: Ian Campbell <ian.campbell@docker.com>
Date: Wed, 4 May 2016 13:21:53 +0000 (+0100)
Subject: VSOCK: do not disconnect socket when peer has shutdown SEND only
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ced4eef10a732bd33ee9289771fada4a07bf508d;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

VSOCK: do not disconnect socket when peer has shutdown SEND only

commit dedc58e067d8c379a15a8a183c5db318201295bb upstream.

The peer may be expecting a reply having sent a request and then done a
shutdown(SHUT_WR), so tearing down the whole socket at this point seems
wrong and breaks for me with a client which does a SHUT_WR.

Looking at other socket family's stream_recvmsg callbacks doing a shutdown
here does not seem to be the norm and removing it does not seem to have
had any adverse effects that I can see.

I'm using Stefan's RFC virtio transport patches, I'm unsure of the impact
on the vmci transport.

Signed-off-by: Ian Campbell <ian.campbell@docker.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: Andy King <acking@vmware.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: Adit Ranadive <aditr@vmware.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 9b88693bcc99..66a9bf52fac6 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1804,27 +1804,8 @@ vsock_stream_recvmsg(struct kiocb *kiocb,
 	else if (sk->sk_shutdown & RCV_SHUTDOWN)
 		err = 0;
 
-	if (copied > 0) {
-		/* We only do these additional bookkeeping/notification steps
-		 * if we actually copied something out of the queue pair
-		 * instead of just peeking ahead.
-		 */
-
-		if (!(flags & MSG_PEEK)) {
-			/* If the other side has shutdown for sending and there
-			 * is nothing more to read, then modify the socket
-			 * state.
-			 */
-			if (vsk->peer_shutdown & SEND_SHUTDOWN) {
-				if (vsock_stream_has_data(vsk) <= 0) {
-					sk->sk_state = SS_UNCONNECTED;
-					sock_set_flag(sk, SOCK_DONE);
-					sk->sk_state_change(sk);
-				}
-			}
-		}
+	if (copied > 0)
 		err = copied;
-	}
 
 out_wait:
 	finish_wait(sk_sleep(sk), &wait);