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. 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  *      @(#)write.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 write(int fd, void *dest, size_t bcount)
  69 {
  70         struct open_file *f = &files[fd];
  71         size_t resid;
  72
  73         if ((unsigned)fd >= SOPEN_MAX || !(f->f_flags & F_WRITE)) {
  74                 errno = EBADF;
  75                 return (-1);
  76         }
  77         if (f->f_flags & F_RAW) {
  78                 twiddle();
  79                 errno = (f->f_dev->dv_strategy)(f->f_devdata, F_WRITE,
  80                         btodb(f->f_offset), bcount, dest, &resid);
  81                 if (errno)
  82                         return (-1);
  83                 f->f_offset += resid;
  84                 return (resid);
  85         }
  86         resid = bcount;
  87         if ((errno = (f->f_ops->fo_write)(f, dest, bcount, &resid)))
  88                 return (-1);
  89         return (0);
  90 }