lib/libstand/write.c

   1 /*      $NetBSD: write.c,v 1.7 1996/06/21 20:29:30 pk Exp $     */
   2 /* $DragonFly: src/lib/libstand/write.c,v 1.3 2005/12/11 02:27:26 swildner 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. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by the University of
  22  *      California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  *
  39  *      @(#)write.c     8.1 (Berkeley) 6/11/93
  40  *
  41  *
  42  * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
  43  * All Rights Reserved.
  44  *
  45  * Author: Alessandro Forin
  46  *
  47  * Permission to use, copy, modify and distribute this software and its
  48  * documentation is hereby granted, provided that both the copyright
  49  * notice and this permission notice appear in all copies of the
  50  * software, derivative works or modified versions, and any portions
  51  * thereof, and that both notices appear in supporting documentation.
  52  *
  53  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  54  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  55  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  56  *
  57  * Carnegie Mellon requests users of this software to return to
  58  *
  59  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  60  *  School of Computer Science
  61  *  Carnegie Mellon University
  62  *  Pittsburgh PA 15213-3890
  63  *
  64  * any improvements or extensions that they make and grant Carnegie the
  65  * rights to redistribute these changes.
  66  */
  67
  68 #include <sys/param.h>
  69 #include "stand.h"
  70
  71 ssize_t
  72 write(int fd, void *dest, size_t bcount)
  73 {
  74         struct open_file *f = &files[fd];
  75         size_t resid;
  76
  77         if ((unsigned)fd >= SOPEN_MAX || !(f->f_flags & F_WRITE)) {
  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_WRITE,
  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->fo_write)(f, dest, bcount, &resid)))
  92                 return (-1);
  93         return (0);
  94 }