opensolaris_uio.c revision 326425 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
27/*        All Rights Reserved   */
28
29/*
30 * University Copyright- Copyright (c) 1982, 1986, 1988
31 * The Regents of the University of California
32 * All Rights Reserved
33 *
34 * University Acknowledgment- Portions of this document are derived from
35 * software developed by the University of California, Berkeley, and its
36 * contributors.
37 */
38
39/*
40 * $FreeBSD: stable/11/sys/cddl/compat/opensolaris/kern/opensolaris_uio.c 326425 2017-12-01 11:06:51Z avg $
41 */
42
43#include <sys/types.h>
44#include <sys/uio.h>
45#include <sys/vnode.h>
46
47/*
48 * same as uiomove() but doesn't modify uio structure.
49 * return in cbytes how many bytes were copied.
50 */
51int
52uiocopy(void *p, size_t n, enum uio_rw rw, struct uio *uio, size_t *cbytes)
53{
54	struct iovec small_iovec[1];
55	struct uio small_uio_clone;
56	struct uio *uio_clone;
57	int error;
58
59	ASSERT3U(uio->uio_rw, ==, rw);
60	if (uio->uio_iovcnt == 1) {
61		small_uio_clone = *uio;
62		small_iovec[0] = *uio->uio_iov;
63		small_uio_clone.uio_iov = small_iovec;
64		uio_clone = &small_uio_clone;
65	} else {
66		uio_clone = cloneuio(uio);
67	}
68
69	error = vn_io_fault_uiomove(p, n, uio_clone);
70	*cbytes = uio->uio_resid - uio_clone->uio_resid;
71	if (uio_clone != &small_uio_clone)
72		free(uio_clone, M_IOV);
73	return (error);
74}
75
76/*
77 * Drop the next n chars out of *uiop.
78 */
79void
80uioskip(uio_t *uio, size_t n)
81{
82	enum uio_seg segflg;
83
84	/* For the full compatibility with illumos. */
85	if (n > uio->uio_resid)
86		return;
87
88	segflg = uio->uio_segflg;
89	uio->uio_segflg = UIO_NOCOPY;
90	uiomove(NULL, n, uio->uio_rw, uio);
91	uio->uio_segflg = segflg;
92}
93