2 * Copyright (c) 1992, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software donated to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
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15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * @(#) Copyright (c) 1992, 1993, 1994 The Regents of the University of California. All rights reserved.
33 * @(#)mount_null.c 8.6 (Berkeley) 4/26/95
34 * $FreeBSD: src/sbin/mount_null/mount_null.c,v 1.13 1999/10/09 11:54:11 phk Exp $
37 #include <sys/param.h>
38 #include <sys/mount.h>
39 #include <vfs/nullfs/null.h>
49 struct mntopt mopts
[] = {
55 static void usage(void) __dead2
;
58 main(int argc
, char **argv
)
60 struct null_args args
;
62 char source
[MAXPATHLEN
];
63 char target
[MAXPATHLEN
];
67 bzero(&args
, sizeof(args
));
69 while ((ch
= getopt(argc
, argv
, "o:u")) != -1)
72 getmntopts(optarg
, mopts
, &mntflags
, 0);
75 mntflags
|= MNT_UPDATE
;
85 * Resolve target and source with realpath(3). Only the mount point
86 * needs be specified in update mode, but mount(8) passes us two
87 * arguments, the second of which is the source directory.
89 if ((mntflags
& MNT_UPDATE
) && argc
== 1) {
91 checkpath(argv
[0], source
);
92 } else if (argc
== 2) {
94 checkpath(argv
[0], target
);
95 checkpath(argv
[1], source
);
100 * Mount points that did not use distinct paths (e.g. / on /mnt)
101 * used to be disallowed because mount linkages were stored in
102 * vnodes and would lead to endlessly recursive trees. DragonFly
103 * stores mount linkages in the namecache topology and does not
104 * have this problem, so paths no longer need to be distinct.
107 error
= getvfsbyname("null", &vfc
);
108 if (error
&& vfsisloadable("null")) {
110 err(EX_OSERR
, "vfsload(null)");
112 error
= getvfsbyname("null", &vfc
);
115 errx(EX_OSERR
, "null/loopback filesystem is not available");
117 if (mount(vfc
.vfc_name
, source
, mntflags
, &args
))
126 "usage: mount_null [-o options] target_fs mount_point\n");
128 " mount_null -u [-o options] mount_point\n");