[RFC PATCH v2 6/9] hv_sock: disable SO_RCVLOWAT support

[Arseniy Krasnov <AVKrasnov@sberdevices.ru>]

For Hyper-V it is quiet difficult to support this socket option,due to
transport internals, so disable it.

Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
---
 net/vmw_vsock/hyperv_transport.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index e111e13b6660..5fab8f356a86 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -802,6 +802,12 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
 	return 0;
 }
 
+static
+int hvs_set_rcvlowat(struct vsock_sock *vsk, int val)
+{
+	return -EOPNOTSUPP;
+}
+
 static struct vsock_transport hvs_transport = {
 	.module                   = THIS_MODULE,
 
@@ -837,6 +843,7 @@ static struct vsock_transport hvs_transport = {
 	.notify_send_pre_enqueue  = hvs_notify_send_pre_enqueue,
 	.notify_send_post_enqueue = hvs_notify_send_post_enqueue,
 
+	.set_rcvlowat             = hvs_set_rcvlowat
 };
 
 static bool hvs_check_transport(struct vsock_sock *vsk)
-- 
2.25.1