[PATCH] vhost: use another variable to store vhost msg result code

[Andy Pei <andy.pei@intel.com>]

Currently in function vhost_user_msg_handler, variable ret is used to
store both vhost msg result code and function call return value.
After this patch, variable ret is used only to store function call
return value, a new variable msg_result is used to store vhost msg
result. This can improve readability.

Signed-off-by: Andy Pei <andy.pei@intel.com>
---
 lib/vhost/vhost_user.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 4ad28ba..dac06c9 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -2969,6 +2969,7 @@ static int is_vring_iotlb(struct virtio_net *dev,
 	struct vhu_msg_context ctx;
 	vhost_message_handler_t *msg_handler;
 	struct rte_vdpa_device *vdpa_dev;
+	int msg_result = RTE_VHOST_MSG_RESULT_OK;
 	int ret;
 	int unlock_required = 0;
 	bool handled;
@@ -3061,8 +3062,8 @@ static int is_vring_iotlb(struct virtio_net *dev,
 	handled = false;
 	if (dev->extern_ops.pre_msg_handle) {
 		RTE_BUILD_BUG_ON(offsetof(struct vhu_msg_context, msg) != 0);
-		ret = (*dev->extern_ops.pre_msg_handle)(dev->vid, &ctx);
-		switch (ret) {
+		msg_result = (*dev->extern_ops.pre_msg_handle)(dev->vid, &ctx);
+		switch (msg_result) {
 		case RTE_VHOST_MSG_RESULT_REPLY:
 			send_vhost_reply(dev, fd, &ctx);
 			/* Fall-through */
@@ -3080,12 +3081,12 @@ static int is_vring_iotlb(struct virtio_net *dev,
 		goto skip_to_post_handle;
 
 	if (!msg_handler->accepts_fd && validate_msg_fds(dev, &ctx, 0) != 0) {
-		ret = RTE_VHOST_MSG_RESULT_ERR;
+		msg_result = RTE_VHOST_MSG_RESULT_ERR;
 	} else {
-		ret = msg_handler->callback(&dev, &ctx, fd);
+		msg_result = msg_handler->callback(&dev, &ctx, fd);
 	}
 
-	switch (ret) {
+	switch (msg_result) {
 	case RTE_VHOST_MSG_RESULT_ERR:
 		VHOST_LOG_CONFIG(dev->ifname, ERR,
 			"processing %s failed.\n",
@@ -3110,11 +3111,11 @@ static int is_vring_iotlb(struct virtio_net *dev,
 	}
 
 skip_to_post_handle:
-	if (ret != RTE_VHOST_MSG_RESULT_ERR &&
+	if (msg_result != RTE_VHOST_MSG_RESULT_ERR &&
 			dev->extern_ops.post_msg_handle) {
 		RTE_BUILD_BUG_ON(offsetof(struct vhu_msg_context, msg) != 0);
-		ret = (*dev->extern_ops.post_msg_handle)(dev->vid, &ctx);
-		switch (ret) {
+		msg_result = (*dev->extern_ops.post_msg_handle)(dev->vid, &ctx);
+		switch (msg_result) {
 		case RTE_VHOST_MSG_RESULT_REPLY:
 			send_vhost_reply(dev, fd, &ctx);
 			/* Fall-through */
@@ -3133,7 +3134,7 @@ static int is_vring_iotlb(struct virtio_net *dev,
 			"vhost message (req: %d) was not handled.\n",
 			request);
 		close_msg_fds(&ctx);
-		ret = RTE_VHOST_MSG_RESULT_ERR;
+		msg_result = RTE_VHOST_MSG_RESULT_ERR;
 	}
 
 	/*
@@ -3142,17 +3143,16 @@ static int is_vring_iotlb(struct virtio_net *dev,
 	 * VHOST_USER_NEED_REPLY was cleared in send_vhost_reply().
 	 */
 	if (ctx.msg.flags & VHOST_USER_NEED_REPLY) {
-		ctx.msg.payload.u64 = ret == RTE_VHOST_MSG_RESULT_ERR;
+		ctx.msg.payload.u64 = msg_result == RTE_VHOST_MSG_RESULT_ERR;
 		ctx.msg.size = sizeof(ctx.msg.payload.u64);
 		ctx.fd_num = 0;
 		send_vhost_reply(dev, fd, &ctx);
-	} else if (ret == RTE_VHOST_MSG_RESULT_ERR) {
+	} else if (msg_result == RTE_VHOST_MSG_RESULT_ERR) {
 		VHOST_LOG_CONFIG(dev->ifname, ERR, "vhost message handling failed.\n");
 		ret = -1;
 		goto unlock;
 	}
 
-	ret = 0;
 	for (i = 0; i < dev->nr_vring; i++) {
 		struct vhost_virtqueue *vq = dev->virtqueue[i];
 		bool cur_ready = vq_is_ready(dev, vq);
-- 
1.8.3.1