Commit b0d0ea50 authored by Jason Wang's avatar Jason Wang Committed by David S. Miller
Browse files

vhost_net: introduce helper to initialize tx iov iter 



Introduce init_iov_iter() in order to be reused by future patch.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 652e4f3e

drivers/vhost/net.c

+17 −9
Original line number Diff line number Diff line
@@ -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 = 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)