[PATCH 3.14 14/17] VSOCK: do not disconnect socket when peer has shutdown SEND only

Greg Kroah-Hartman
2016-05-17T01:14:33Z

From: Ian Campbell <ian.campbell@docker.com>

[ 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@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>
---
net/vmw_vsock/af_vsock.c | 21 +--------------------
1 file changed, 1 insertion(+), 20 deletions(-)

--- 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);