xref: /freebsd-src/sys/contrib/openzfs/module/os/freebsd/spl/spl_uio.c (revision 4e859e67dde2cb4a583d340b27793a255f62f53e)
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 https://opensource.org/licenses/CDDL-1.0.
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  * $FreeBSD$
41  */
42 
43 #include <sys/param.h>
44 #include <sys/uio_impl.h>
45 #include <sys/vnode.h>
46 #include <sys/zfs_znode.h>
47 
48 static void
49 zfs_freeuio(struct uio *uio)
50 {
51 #if __FreeBSD_version > 1500013
52 	freeuio(uio);
53 #else
54 	free(uio, M_IOV);
55 #endif
56 }
57 
58 int
59 zfs_uiomove(void *cp, size_t n, zfs_uio_rw_t dir, zfs_uio_t *uio)
60 {
61 	ASSERT3U(zfs_uio_rw(uio), ==, dir);
62 	return (uiomove(cp, (int)n, GET_UIO_STRUCT(uio)));
63 }
64 
65 /*
66  * same as zfs_uiomove() but doesn't modify uio structure.
67  * return in cbytes how many bytes were copied.
68  */
69 int
70 zfs_uiocopy(void *p, size_t n, zfs_uio_rw_t rw, zfs_uio_t *uio, size_t *cbytes)
71 {
72 	struct iovec small_iovec[1];
73 	struct uio small_uio_clone;
74 	struct uio *uio_clone;
75 	int error;
76 
77 	ASSERT3U(zfs_uio_rw(uio), ==, rw);
78 	if (zfs_uio_iovcnt(uio) == 1) {
79 		small_uio_clone = *(GET_UIO_STRUCT(uio));
80 		small_iovec[0] = *(GET_UIO_STRUCT(uio)->uio_iov);
81 		small_uio_clone.uio_iov = small_iovec;
82 		uio_clone = &small_uio_clone;
83 	} else {
84 		uio_clone = cloneuio(GET_UIO_STRUCT(uio));
85 	}
86 
87 	error = vn_io_fault_uiomove(p, n, uio_clone);
88 	*cbytes = zfs_uio_resid(uio) - uio_clone->uio_resid;
89 	if (uio_clone != &small_uio_clone)
90 		zfs_freeuio(uio_clone);
91 	return (error);
92 }
93 
94 /*
95  * Drop the next n chars out of *uiop.
96  */
97 void
98 zfs_uioskip(zfs_uio_t *uio, size_t n)
99 {
100 	zfs_uio_seg_t segflg;
101 
102 	/* For the full compatibility with illumos. */
103 	if (n > zfs_uio_resid(uio))
104 		return;
105 
106 	segflg = zfs_uio_segflg(uio);
107 	zfs_uio_segflg(uio) = UIO_NOCOPY;
108 	zfs_uiomove(NULL, n, zfs_uio_rw(uio), uio);
109 	zfs_uio_segflg(uio) = segflg;
110 }
111 
112 int
113 zfs_uio_fault_move(void *p, size_t n, zfs_uio_rw_t dir, zfs_uio_t *uio)
114 {
115 	ASSERT3U(zfs_uio_rw(uio), ==, dir);
116 	return (vn_io_fault_uiomove(p, n, GET_UIO_STRUCT(uio)));
117 }
118