virtio-serial-bus: use correct lengths in control_out() message

Original code has one thing to process (cur_len), requests to
convert from iovec to buf another thing (len which is actually max_len),
and processes something else (copied).  Whole thing is very difficult
to understand, even if it does a right thing.  The iov_to_buf()
conversion in this case will always return cur_len, because it is
the length of the iovec it was asked to process, and the size we
asked to convert is the same or larger, and iov_to_buf() will stop
at reaching either iov or buf.

Make the code saner by doing the only sane thing: dropping `copied'
which is always the same as `cur_len' but just introduces questions.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index 72287d1..1e477e5 100644 (file)
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -454,7 +454,7 @@ static void control_out(VirtIODevice *vdev, VirtQueue *vq)
     len = 0;
     buf = NULL;
     while (virtqueue_pop(vq, &elem)) {
-        size_t cur_len, copied;
+        size_t cur_len;
 
         cur_len = iov_size(elem.out_sg, elem.out_num);
         /*
@@ -467,9 +467,9 @@ static void control_out(VirtIODevice *vdev, VirtQueue *vq)
             buf = g_malloc(cur_len);
             len = cur_len;
         }
-        copied = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, len);
+        iov_to_buf(elem.out_sg, elem.out_num, buf, 0, cur_len);
 
-        handle_control_message(vser, buf, copied);
+        handle_control_message(vser, buf, cur_len);
         virtqueue_push(vq, &elem, 0);
     }
     g_free(buf);