minix/sys/lib/libsa/open.c
2012-02-09 18:48:13 +01:00

158 lines
4.6 KiB
C

/* $NetBSD: open.c,v 1.26 2007/11/24 13:20:56 isaki Exp $ */
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)open.c 8.1 (Berkeley) 6/11/93
*
*
* Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Author: Alessandro Forin
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include "stand.h"
/*
* File primitives proper
*/
#ifdef HELLO_CTAGS
oopen(){}
#endif
int
#ifndef __INTERNAL_LIBSA_CREAD
open(const char *fname, int mode)
#else
oopen(const char *fname, int mode)
#endif
{
struct open_file *f;
int fd, error;
#if !defined(LIBSA_SINGLE_FILESYSTEM)
int i, besterror;
#endif
char *file;
/* find a free file descriptor */
for (fd = 0, f = files; fd < SOPEN_MAX; fd++, f++)
if (f->f_flags == 0)
goto fnd;
errno = EMFILE;
return -1;
fnd:
/*
* Try to open the device.
* Convert open mode (0,1,2) to F_READ, F_WRITE.
*/
f->f_flags = mode + 1;
#if !defined(LIBSA_SINGLE_DEVICE)
f->f_dev = (struct devsw *)0;
#endif
#if !defined(LIBSA_SINGLE_FILESYSTEM)
f->f_ops = (struct fs_ops *)0;
#endif
#if !defined(LIBSA_NO_RAW_ACCESS)
f->f_offset = 0;
#endif
file = (char *)0;
error = devopen(f, fname, &file);
if (error
#if !defined(LIBSA_SINGLE_DEVICE)
|| (((f->f_flags & F_NODEV) == 0) &&
f->f_dev == (struct devsw *)0)
#endif
)
goto err;
#if !defined(LIBSA_NO_RAW_ACCESS)
/* see if we opened a raw device; otherwise, 'file' is the file name. */
if (file == (char *)0 || *file == '\0') {
f->f_flags |= F_RAW;
return fd;
}
#endif
/* pass file name to the different filesystem open routines */
#if !defined(LIBSA_SINGLE_FILESYSTEM)
besterror = ENOENT;
for (i = 0; i < nfsys; i++) {
error = FS_OPEN(&file_system[i])(file, f);
if (error == 0) {
f->f_ops = &file_system[i];
return fd;
}
if (error != EINVAL)
besterror = error;
}
error = besterror;
#else
error = FS_OPEN(&file_system[i])(file, f);
if (error == 0)
return fd;
if (error == EINVAL)
error = ENOENT;
#endif
if ((f->f_flags & F_NODEV) == 0) {
#if !defined(LIBSA_SINGLE_DEVICE)
if (DEV_CLOSE(f->f_dev) != NULL)
#endif
(void)DEV_CLOSE(f->f_dev)(f);
}
err:
f->f_flags = 0;
errno = error;
return -1;
}