sblock.c revision 111111 
1/*
2 * Copyright (c) 2002 Juli Mallett.  All rights reserved.
3 *
4 * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
5 * FreeBSD project.  Redistribution and use in source and binary forms, with
6 * or without modification, are permitted provided that the following
7 * conditions are met:
8 *
9 * 1. Redistribution of source code must retain the above copyright notice,
10 *    this list of conditions and the following disclaimer.
11 * 2. Redistribution in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: head/lib/libufs/sblock.c 111111 2003-02-19 00:32:48Z jmallett $");
30
31#include <sys/param.h>
32#include <sys/mount.h>
33#include <sys/disklabel.h>
34#include <sys/stat.h>
35
36#include <ufs/ufs/ufsmount.h>
37#include <ufs/ufs/dinode.h>
38#include <ufs/ffs/fs.h>
39
40#include <errno.h>
41#include <stdio.h>
42#include <string.h>
43#include <unistd.h>
44
45#include <libufs.h>
46
47static int superblocks[] = SBLOCKSEARCH;
48
49int
50sbread(struct uufsd *disk)
51{
52	struct fs *fs;
53	int sb, superblock;
54
55	ERROR(disk, NULL);
56
57	fs = &disk->d_fs;
58	superblock = superblocks[0];
59
60	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
61		if (bread(disk, superblock, disk->d_sb, SBLOCKSIZE) == -1) {
62			ERROR(disk, "non-existent or truncated superblock");
63			return -1;
64		}
65		if (fs->fs_magic == FS_UFS1_MAGIC)
66			disk->d_ufs = 1;
67		if (fs->fs_magic == FS_UFS2_MAGIC &&
68		    fs->fs_sblockloc == superblock)
69			disk->d_ufs = 2;
70		if (fs->fs_bsize <= MAXBSIZE &&
71		    (size_t)fs->fs_bsize >= sizeof(*fs)) {
72			if (disk->d_ufs)
73				break;
74		}
75		disk->d_ufs = 0;
76	}
77	if (superblock == -1 || disk->d_ufs == 0) {
78		/*
79		 * Other error cases will result in errno being set, here we
80		 * must set it to indicate no superblock could be found with
81		 * which to associate this disk/filesystem.
82		 */
83		ERROR(disk, "no usable known superblock found");
84		errno = ENOENT;
85		return -1;
86	}
87	disk->d_bsize = fs->fs_fsize / fsbtodb(fs, 1);
88	disk->d_sblock = superblock / disk->d_bsize;
89	return 0;
90}
91
92int
93sbwrite(struct uufsd *disk, int all)
94{
95	struct fs *fs;
96	int i;
97
98	ERROR(disk, NULL);
99
100	fs = &disk->d_fs;
101
102	if (!disk->d_sblock) {
103		disk->d_sblock = disk->d_fs.fs_sblockloc / disk->d_bsize;
104	}
105
106	if (bwrite(disk, disk->d_sblock, fs, SBLOCKSIZE) == -1) {
107		ERROR(disk, "failed to write superblock");
108		return -1;
109	}
110	if (all) {
111		for (i = 0; i < fs->fs_ncg; i++)
112			if (bwrite(disk, fsbtodb(fs, cgsblock(fs, i)),
113			    fs, SBLOCKSIZE) == -1) {
114				ERROR(disk, "failed to update a superblock");
115				return -1;
116			}
117	}
118	return 0;
119}
120