Revert "9p: init_in_iov_from_pdu can truncate the size"

This reverts commit 16724a173049ac29c7b5ade741da93a0f46edff7.
It causes https://bugs.launchpad.net/bugs/1877688.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20200521192627.15259-1-sstabellini@kernel.org>
Signed-off-by: Greg Kurz <groug@kaod.org>

1 files changed, 4 insertions, 7 deletions

diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index e5b44977c7..36f3aa9352 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -147,22 +147,19 @@ static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 }
 
 static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
-                                        unsigned int *pniov, size_t *size)
+                                        unsigned int *pniov, size_t size)
 {
     V9fsState *s = pdu->s;
     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
     VirtQueueElement *elem = v->elems[pdu->idx];
     size_t buf_size = iov_size(elem->in_sg, elem->in_num);
 
-    if (buf_size < P9_IOHDRSZ) {
+    if (buf_size < size) {
         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 
         virtio_error(vdev,
-                     "VirtFS reply type %d needs %zu bytes, buffer has %zu, less than minimum",
-                     pdu->id + 1, *size, buf_size);
-    }
-    if (buf_size < *size) {
-        *size = buf_size;
+                     "VirtFS reply type %d needs %zu bytes, buffer has %zu",
+                     pdu->id + 1, size, buf_size);
     }
 
     *piov = elem->in_sg;