[vhost] fix 'direction' argument of iov_iter_{init,bvec}()

READ means "data destination", WRITE - "data source".

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

drivers/vhost/vhost.c

@@ -832,7 +832,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to,
 				     VHOST_ACCESS_WO);
 		if (ret < 0)
 			goto out;
-		iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size);
+		iov_iter_init(&t, READ, vq->iotlb_iov, ret, size);
 		ret = copy_to_iter(from, size, &t);
 		if (ret == size)
 			ret = 0;
@@ -871,7 +871,7 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,
 			       (unsigned long long) size);
 			goto out;
 		}
-		iov_iter_init(&f, READ, vq->iotlb_iov, ret, size);
+		iov_iter_init(&f, WRITE, vq->iotlb_iov, ret, size);
 		ret = copy_from_iter(to, size, &f);
 		if (ret == size)
 			ret = 0;
@@ -2135,7 +2135,7 @@ static int get_indirect(struct vhost_virtqueue *vq,
 			vq_err(vq, "Translation failure %d in indirect.\n", ret);
 		return ret;
 	}
-	iov_iter_init(&from, READ, vq->indirect, ret, len);
+	iov_iter_init(&from, WRITE, vq->indirect, ret, len);
 	count = len / sizeof desc;
 	/* Buffers are chained via a 16 bit next field, so
 	 * we can have at most 2^16 of these. */

drivers/vhost/vringh.c

@@ -1162,7 +1162,7 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
 		else if (ret < 0)
 			return ret;
 
-		iov_iter_bvec(&iter, READ, iov, ret, translated);
+		iov_iter_bvec(&iter, WRITE, iov, ret, translated);
 
 		ret = copy_from_iter(dst, translated, &iter);
 		if (ret < 0)
@@ -1195,7 +1195,7 @@ static inline int copy_to_iotlb(const struct vringh *vrh, void *dst,
 		else if (ret < 0)
 			return ret;
 
-		iov_iter_bvec(&iter, WRITE, iov, ret, translated);
+		iov_iter_bvec(&iter, READ, iov, ret, translated);
 
 		ret = copy_to_iter(src, translated, &iter);
 		if (ret < 0)