[PATCH v2] vhost: use dedicated variable for vhost message result code

[Andy Pei]

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 dedicated variable msg_result is used to
store vhost msg result. This can improve readability.

Signed-off-by: Andy Pei <andy....@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 0182090..6d93495 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -2954,6 +2954,7 @@ 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;
@@ -3046,8 +3047,8 @@ 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 */
@@ -3065,12 +3066,12 @@ 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",
@@ -3095,11 +3096,11 @@ 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 */
@@ -3118,7 +3119,7 @@ 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;
        }
 
        /*
@@ -3127,17 +3128,16 @@ 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