Annotation of sys/lib/libsa/read.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: read.c,v 1.7 2003/08/11 06:23:09 deraadt Exp $ */
2: /* $NetBSD: read.c,v 1.7 1996/06/21 20:29:28 pk Exp $ */
3:
4: /*-
5: * Copyright (c) 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * This code is derived from software contributed to Berkeley by
9: * The Mach Operating System project at Carnegie-Mellon University.
10: *
11: * Redistribution and use in source and binary forms, with or without
12: * modification, are permitted provided that the following conditions
13: * are met:
14: * 1. Redistributions of source code must retain the above copyright
15: * notice, this list of conditions and the following disclaimer.
16: * 2. Redistributions in binary form must reproduce the above copyright
17: * notice, this list of conditions and the following disclaimer in the
18: * documentation and/or other materials provided with the distribution.
19: * 3. Neither the name of the University nor the names of its contributors
20: * may be used to endorse or promote products derived from this software
21: * without specific prior written permission.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33: * SUCH DAMAGE.
34: *
35: * @(#)read.c 8.1 (Berkeley) 6/11/93
36: *
37: *
38: * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
39: * All Rights Reserved.
40: *
41: * Author: Alessandro Forin
42: *
43: * Permission to use, copy, modify and distribute this software and its
44: * documentation is hereby granted, provided that both the copyright
45: * notice and this permission notice appear in all copies of the
46: * software, derivative works or modified versions, and any portions
47: * thereof, and that both notices appear in supporting documentation.
48: *
49: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
50: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
51: * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52: *
53: * Carnegie Mellon requests users of this software to return to
54: *
55: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
56: * School of Computer Science
57: * Carnegie Mellon University
58: * Pittsburgh PA 15213-3890
59: *
60: * any improvements or extensions that they make and grant Carnegie the
61: * rights to redistribute these changes.
62: */
63:
64: #include <sys/param.h>
65: #include "stand.h"
66:
67: ssize_t
68: #ifndef __INTERNAL_LIBSA_CREAD
69: read(int fd, void *dest, size_t bcount)
70: #else
71: oread(int fd, void *dest, size_t bcount)
72: #endif
73: {
74: struct open_file *f = &files[fd];
75: size_t resid;
76:
77: if ((unsigned)fd >= SOPEN_MAX || !(f->f_flags & F_READ)) {
78: errno = EBADF;
79: return (-1);
80: }
81: if (f->f_flags & F_RAW) {
82: twiddle();
83: errno = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
84: btodb(f->f_offset), bcount, dest, &resid);
85: if (errno)
86: return (-1);
87: f->f_offset += resid;
88: return (resid);
89: }
90: resid = bcount;
91: if ((errno = (f->f_ops->read)(f, dest, bcount, &resid)))
92: return (-1);
93: return (ssize_t)(bcount - resid);
94: }
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