@@ -466,6 +466,18 @@ static bool vhost_exceeds_maxpend(struct vhost_net *net)
min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2);
}
+static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
+ size_t hdr_size, int out)
+{
+ /* Skip header. TODO: support TSO. */
+ size_t len = iov_length(vq->iov, out);
+
+ iov_iter_init(iter, WRITE, vq->iov, out, len);
+ iov_iter_advance(iter, hdr_size);
+
+ return iov_iter_count(iter);
+}
+
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
static void handle_tx(struct vhost_net *net)
@@ -531,18 +543,14 @@ static void handle_tx(struct vhost_net *net)
"out %d, int %d\n", out, in);
break;
}
- /* Skip header. TODO: support TSO. */
- len = iov_length(vq->iov, out);
- iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
- iov_iter_advance(&msg.msg_iter, hdr_size);
+
/* Sanity check */
- if (!msg_data_left(&msg)) {
- vq_err(vq, "Unexpected header len for TX: "
- "%zd expected %zd\n",
- len, hdr_size);
+ len = init_iov_iter(vq, &msg.msg_iter, hdr_size, out);
+ if (!len) {
+ vq_err(vq, "Unexpected header len for TX: %zd expected %zd\n",
+ len, hdr_size);
break;
}
- len = msg_data_left(&msg);
zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
&& !vhost_exceeds_maxpend(net)
Introduce init_iov_iter() in order to be reused by future patch. Signed-off-by: Jason Wang <jasowang@redhat.com> --- drivers/vhost/net.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)