[3.19.y-ckt stable] Patch "VSOCK: do not disconnect socket when peer has shutdown SEND only" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt22.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 5175ed6b780a668391e00dba063cdf5ae175c4df Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell at docker.com>
Date: Wed, 4 May 2016 14:21:53 +0100
Subject: VSOCK: do not disconnect socket when peer has shutdown SEND only

[ Upstream commit dedc58e067d8c379a15a8a183c5db318201295bb ]

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 at docker.com>
Cc: "David S. Miller" <davem at davemloft.net>
Cc: Stefan Hajnoczi <stefanha at redhat.com>
Cc: Claudio Imbrenda <imbrenda at linux.vnet.ibm.com>
Cc: Andy King <acking at vmware.com>
Cc: Dmitry Torokhov <dtor at vmware.com>
Cc: Jorgen Hansen <jhansen at vmware.com>
Cc: Adit Ranadive <aditr at vmware.com>
Cc: netdev at vger.kernel.org
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/vmw_vsock/af_vsock.c | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 1d0e39c..316e856 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1796,27 +1796,8 @@ 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);
--
2.7.4