1 /*
2 * Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
25 *
26 * http://www.sgi.com
27 *
28 * For further information regarding this notice, see:
29 *
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31 */
32
33 #include <xfs.h>
34
35 /* Read from kernel buffer at src to user/kernel buffer defined
36 * by the uio structure. Advance the pointer in the uio struct
37 * as we go.
38 */
39 int
uio_read(caddr_t src,size_t len,struct uio * uio)40 uio_read(caddr_t src, size_t len, struct uio *uio)
41 {
42 size_t count;
43
44 if (!len || !uio->uio_resid)
45 return 0;
46
47 count = uio->uio_iov->iov_len;
48 if (!count)
49 return 0;
50 if (count > len)
51 count = len;
52
53 if (uio->uio_segflg == UIO_USERSPACE) {
54 if (copy_to_user(uio->uio_iov->iov_base, src, count))
55 return EFAULT;
56 } else {
57 ASSERT(uio->uio_segflg == UIO_SYSSPACE);
58 memcpy(uio->uio_iov->iov_base, src, count);
59 }
60
61 uio->uio_iov->iov_base = (void*)((char*)uio->uio_iov->iov_base + count);
62 uio->uio_iov->iov_len -= count;
63 uio->uio_offset += count;
64 uio->uio_resid -= count;
65 return 0;
66 }
67