1 files changed, 11 insertions, 43 deletions

diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 982a8dc49e03..62dcdf082349 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Hyper-V transport for vsock
  *
@@ -6,16 +7,6 @@
  * support in the VM by introducing the new vsock transport.
  *
  * Copyright (c) 2017, Microsoft Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
  */
 #include <linux/module.h>
 #include <linux/vmalloc.h>
@@ -220,18 +211,6 @@ static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan)
 	set_channel_pending_send_size(chan,
 				      HVS_PKT_LEN(HVS_SEND_BUF_SIZE));
 
-	/* See hvs_stream_has_space(): we must make sure the host has seen
-	 * the new pending send size, before we can re-check the writable
-	 * bytes.
-	 */
-	virt_mb();
-}
-
-static void hvs_clear_channel_pending_send_size(struct vmbus_channel *chan)
-{
-	set_channel_pending_send_size(chan, 0);
-
-	/* Ditto */
 	virt_mb();
 }
 
@@ -301,9 +280,6 @@ static void hvs_channel_cb(void *ctx)
 	if (hvs_channel_readable(chan))
 		sk->sk_data_ready(sk);
 
-	/* See hvs_stream_has_space(): when we reach here, the writable bytes
-	 * may be already less than HVS_PKT_LEN(HVS_SEND_BUF_SIZE).
-	 */
 	if (hv_get_bytes_to_write(&chan->outbound) > 0)
 		sk->sk_write_space(sk);
 }
@@ -344,8 +320,8 @@ static void hvs_open_connection(struct vmbus_channel *chan)
 
 	struct sockaddr_vm addr;
 	struct sock *sk, *new = NULL;
-	struct vsock_sock *vnew;
-	struct hvsock *hvs, *hvs_new;
+	struct vsock_sock *vnew = NULL;
+	struct hvsock *hvs, *hvs_new = NULL;
 	int ret;
 
 	if_type = &chan->offermsg.offer.if_type;
@@ -404,6 +380,13 @@ static void hvs_open_connection(struct vmbus_channel *chan)
 	set_per_channel_state(chan, conn_from_host ? new : sk);
 	vmbus_set_chn_rescind_callback(chan, hvs_close_connection);
 
+	/* Set the pending send size to max packet size to always get
+	 * notifications from the host when there is enough writable space.
+	 * The host is optimized to send notifications only when the pending
+	 * size boundary is crossed, and not always.
+	 */
+	hvs_set_channel_pending_send_size(chan);
+
 	if (conn_from_host) {
 		new->sk_state = TCP_ESTABLISHED;
 		sk->sk_ack_backlog++;
@@ -697,23 +680,8 @@ static s64 hvs_stream_has_data(struct vsock_sock *vsk)
 static s64 hvs_stream_has_space(struct vsock_sock *vsk)
 {
 	struct hvsock *hvs = vsk->trans;
-	struct vmbus_channel *chan = hvs->chan;
-	s64 ret;
 
-	ret = hvs_channel_writable_bytes(chan);
-	if (ret > 0)  {
-		hvs_clear_channel_pending_send_size(chan);
-	} else {
-		/* See hvs_channel_cb() */
-		hvs_set_channel_pending_send_size(chan);
-
-		/* Re-check the writable bytes to avoid race */
-		ret = hvs_channel_writable_bytes(chan);
-		if (ret > 0)
-			hvs_clear_channel_pending_send_size(chan);
-	}
-
-	return ret;
+	return hvs_channel_writable_bytes(hvs->chan);
 }
 
 static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk)