xref: /freebsd/stand/libsa/write.c (revision d7d962ead0b6e5e8a39202d0590022082bf5bfb6)
1 /*	$NetBSD: write.c,v 1.7 1996/06/21 20:29:30 pk Exp $	*/
2 
3 /*-
4  * Copyright (c) 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * The Mach Operating System project at Carnegie-Mellon University.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)write.c	8.1 (Berkeley) 6/11/93
35  *
36  *
37  * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
38  * All Rights Reserved.
39  *
40  * Author: Alessandro Forin
41  *
42  * Permission to use, copy, modify and distribute this software and its
43  * documentation is hereby granted, provided that both the copyright
44  * notice and this permission notice appear in all copies of the
45  * software, derivative works or modified versions, and any portions
46  * thereof, and that both notices appear in supporting documentation.
47  *
48  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
50  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51  *
52  * Carnegie Mellon requests users of this software to return to
53  *
54  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
55  *  School of Computer Science
56  *  Carnegie Mellon University
57  *  Pittsburgh PA 15213-3890
58  *
59  * any improvements or extensions that they make and grant Carnegie the
60  * rights to redistribute these changes.
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 #include <sys/param.h>
67 #include "stand.h"
68 
69 ssize_t
70 write(int fd, const void *dest, size_t bcount)
71 {
72 	struct open_file *f;
73 	size_t resid;
74 
75 	f = fd2open_file(fd);
76 	if (f == NULL || !(f->f_flags & F_WRITE)) {
77 		errno = EBADF;
78 		return (-1);
79 	}
80 	if (f->f_flags & F_RAW) {
81 		twiddle(4);
82 		errno = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
83 		    btodb(f->f_offset), bcount, __DECONST(void *, dest),
84 		    &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->fo_write)(f, dest, bcount, &resid)))
92 		return (-1);
93 	return (bcount - resid);
94 }
95