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Diffstat (limited to 'usr/src/boot/libsa/open.c')
| -rw-r--r-- | usr/src/boot/libsa/open.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/usr/src/boot/libsa/open.c b/usr/src/boot/libsa/open.c new file mode 100644 index 0000000000..6d026f1ca6 --- /dev/null +++ b/usr/src/boot/libsa/open.c @@ -0,0 +1,204 @@ +/* $NetBSD: open.c,v 1.16 1997/01/28 09:41:03 pk 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 <sys/cdefs.h> + +#include "stand.h" + +struct fs_ops *exclusive_file_system; + +/* + * Open file list. The current implementation and assumption is, + * we only remove entries from tail and we only add new entries to tail. + * This decision is to keep file id management simple - we get list + * entries ordered by continiously growing f_id field. + * If we do have multiple files open and we do close file not from tail, + * this entry will be marked unused. open() will reuse unused entry, or + * close will free all unused tail entries. + * + * Only case we expect open file list to grow long, is with zfs pools with + * many disks. + */ +file_list_t files = TAILQ_HEAD_INITIALIZER(files); + +/* + * Walk file list and return pointer to open_file structure. + * if fd is < 0, return first unused open_file. + */ +struct open_file * +fd2open_file(int fd) +{ + struct open_file *f; + + TAILQ_FOREACH(f, &files, f_link) { + if (fd >= 0) { + if (f->f_id == fd) + break; + continue; + } + if (f->f_flags == 0) + break; + } + return (f); +} + +static int +o_gethandle(struct open_file **ptr) +{ + struct open_file *f, *last; + + /* Pick up unused entry */ + f = fd2open_file(-1); + if (f != NULL) { + *ptr = f; + return (f->f_id); + } + + /* Add new entry */ + f = calloc(1, sizeof (*f)); + if (f == NULL) + return (-1); + + last = TAILQ_LAST(&files, file_list); + if (last != NULL) + f->f_id = last->f_id + 1; + TAILQ_INSERT_TAIL(&files, f, f_link); + + *ptr = f; + return (f->f_id); +} + +static void +o_rainit(struct open_file *f) +{ + f->f_rabuf = malloc(SOPEN_RASIZE); + f->f_ralen = 0; + f->f_raoffset = 0; +} + +int +open(const char *fname, int mode) +{ + struct fs_ops *fs; + struct open_file *f; + int fd, i, error, besterror; + const char *file; + + if ((fd = o_gethandle(&f)) == -1) { + errno = EMFILE; + return (-1); + } + + f->f_flags = mode + 1; + f->f_dev = NULL; + f->f_ops = NULL; + f->f_offset = 0; + f->f_devdata = NULL; + file = NULL; + + if (exclusive_file_system != NULL) { + fs = exclusive_file_system; + error = (fs->fo_open)(fname, f); + if (error == 0) + goto ok; + goto err; + } + + error = devopen(f, fname, &file); + if (error || + (((f->f_flags & F_NODEV) == 0) && f->f_dev == NULL)) + goto err; + + /* see if we opened a raw device; otherwise, 'file' is the file name. */ + if (file == NULL || *file == '\0') { + f->f_flags |= F_RAW; + f->f_rabuf = NULL; + return (fd); + } + + /* pass file name to the different filesystem open routines */ + besterror = ENOENT; + for (i = 0; file_system[i] != NULL; i++) { + fs = file_system[i]; + error = (fs->fo_open)(file, f); + if (error == 0) + goto ok; + if (error != EINVAL) + besterror = error; + } + error = besterror; + + if ((f->f_flags & F_NODEV) == 0 && f->f_dev != NULL) + f->f_dev->dv_close(f); + if (error) + devclose(f); + +err: + f->f_flags = 0; + errno = error; + return (-1); + +ok: + f->f_ops = fs; + o_rainit(f); + return (fd); +} |