read.c revision 1.14 1 1.14 isaki /* $NetBSD: read.c,v 1.14 2007/11/24 13:20:57 isaki Exp $ */
2 1.3 cgd
3 1.1 brezak /*-
4 1.1 brezak * Copyright (c) 1993
5 1.1 brezak * The Regents of the University of California. All rights reserved.
6 1.1 brezak *
7 1.1 brezak * This code is derived from software contributed to Berkeley by
8 1.1 brezak * The Mach Operating System project at Carnegie-Mellon University.
9 1.1 brezak *
10 1.1 brezak * Redistribution and use in source and binary forms, with or without
11 1.1 brezak * modification, are permitted provided that the following conditions
12 1.1 brezak * are met:
13 1.1 brezak * 1. Redistributions of source code must retain the above copyright
14 1.1 brezak * notice, this list of conditions and the following disclaimer.
15 1.1 brezak * 2. Redistributions in binary form must reproduce the above copyright
16 1.1 brezak * notice, this list of conditions and the following disclaimer in the
17 1.1 brezak * documentation and/or other materials provided with the distribution.
18 1.11 agc * 3. Neither the name of the University nor the names of its contributors
19 1.1 brezak * may be used to endorse or promote products derived from this software
20 1.1 brezak * without specific prior written permission.
21 1.1 brezak *
22 1.1 brezak * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 1.1 brezak * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 1.1 brezak * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 1.1 brezak * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 1.1 brezak * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 1.1 brezak * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 1.1 brezak * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 1.1 brezak * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 1.1 brezak * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 1.1 brezak * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 1.1 brezak * SUCH DAMAGE.
33 1.1 brezak *
34 1.3 cgd * @(#)read.c 8.1 (Berkeley) 6/11/93
35 1.12 perry *
36 1.1 brezak *
37 1.1 brezak * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
38 1.1 brezak * All Rights Reserved.
39 1.1 brezak *
40 1.1 brezak * Author: Alessandro Forin
41 1.12 perry *
42 1.1 brezak * Permission to use, copy, modify and distribute this software and its
43 1.1 brezak * documentation is hereby granted, provided that both the copyright
44 1.1 brezak * notice and this permission notice appear in all copies of the
45 1.1 brezak * software, derivative works or modified versions, and any portions
46 1.1 brezak * thereof, and that both notices appear in supporting documentation.
47 1.12 perry *
48 1.1 brezak * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 1.1 brezak * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
50 1.1 brezak * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51 1.12 perry *
52 1.1 brezak * Carnegie Mellon requests users of this software to return to
53 1.12 perry *
54 1.1 brezak * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU
55 1.1 brezak * School of Computer Science
56 1.1 brezak * Carnegie Mellon University
57 1.1 brezak * Pittsburgh PA 15213-3890
58 1.12 perry *
59 1.1 brezak * any improvements or extensions that they make and grant Carnegie the
60 1.1 brezak * rights to redistribute these changes.
61 1.1 brezak */
62 1.1 brezak
63 1.6 pk #include <sys/param.h>
64 1.1 brezak #include "stand.h"
65 1.1 brezak
66 1.5 pk ssize_t
67 1.8 cgd #ifndef __INTERNAL_LIBSA_CREAD
68 1.14 isaki read(int fd, void *dest, size_t bcount)
69 1.8 cgd #else
70 1.14 isaki oread(int fd, void *dest, size_t bcount)
71 1.8 cgd #endif
72 1.1 brezak {
73 1.10 augustss struct open_file *f = &files[fd];
74 1.5 pk size_t resid;
75 1.1 brezak
76 1.9 cgd #if !defined(LIBSA_NO_FD_CHECKING)
77 1.1 brezak if ((unsigned)fd >= SOPEN_MAX || !(f->f_flags & F_READ)) {
78 1.1 brezak errno = EBADF;
79 1.14 isaki return -1;
80 1.1 brezak }
81 1.9 cgd #endif
82 1.9 cgd #if !defined(LIBSA_NO_RAW_ACCESS)
83 1.1 brezak if (f->f_flags & F_RAW) {
84 1.9 cgd #if !defined(LIBSA_NO_TWIDDLE)
85 1.4 mycroft twiddle();
86 1.9 cgd #endif
87 1.9 cgd errno = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
88 1.6 pk btodb(f->f_offset), bcount, dest, &resid);
89 1.1 brezak if (errno)
90 1.14 isaki return -1;
91 1.7 pk f->f_offset += resid;
92 1.14 isaki return resid;
93 1.1 brezak }
94 1.9 cgd #endif
95 1.1 brezak resid = bcount;
96 1.9 cgd if ((errno = FS_READ(f->f_ops)(f, dest, bcount, &resid)))
97 1.14 isaki return -1;
98 1.5 pk return (ssize_t)(bcount - resid);
99 1.1 brezak }
100