Ventoy/Unix/ventoy_unix_src/DragonFly/mount_null.c
2020-12-31 21:56:58 +08:00

107 lines
3.3 KiB
C

/*
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
* @(#) Copyright (c) 1992, 1993, 1994 The Regents of the University of California. All rights reserved.
* @(#)mount_null.c 8.6 (Berkeley) 4/26/95
* $FreeBSD: src/sbin/mount_null/mount_null.c,v 1.13 1999/10/09 11:54:11 phk Exp $
*/
#include <sys/param.h>
#include <sys/mount.h>
#include <vfs/nullfs/null.h>
#include <err.h>
#include <mntopts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
static struct mntopt mopts[] = {
MOPT_STDOPTS,
MOPT_UPDATE,
MOPT_NULL
};
static void usage(void) __dead2;
int
mount_null(const char *src, const char *dst)
{
struct null_args args;
int ch, mntflags;
char source[MAXPATHLEN];
char target[MAXPATHLEN];
struct vfsconf vfc;
int error;
bzero(&args, sizeof(args));
mntflags = 0;
args.target = target;
checkpath(src, target);
checkpath(dst, source);
/*
* Mount points that did not use distinct paths (e.g. / on /mnt)
* used to be disallowed because mount linkages were stored in
* vnodes and would lead to endlessly recursive trees. DragonFly
* stores mount linkages in the namecache topology and does not
* have this problem, so paths no longer need to be distinct.
*/
error = getvfsbyname("null", &vfc);
if (error && vfsisloadable("null")) {
if(vfsload("null"))
err(EX_OSERR, "vfsload(null)");
endvfsent();
error = getvfsbyname("null", &vfc);
}
if (error)
errx(EX_OSERR, "null/loopback filesystem is not available");
if (mount(vfc.vfc_name, source, mntflags, &args))
err(1, NULL);
return 0;
}
static void
usage(void)
{
fprintf(stderr,
"usage: mount_null [-o options] target_fs mount_point\n");
fprintf(stderr,
" mount_null -u [-o options] mount_point\n");
exit(1);
}