sblock.c revision 107294 
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 107294 2002-11-27 02:18:58Z mckusick $");
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 <fcntl.h>
42#include <stdio.h>
43#include <string.h>
44#include <unistd.h>
45
46#include <libufs.h>
47
48static int superblocks[] = SBLOCKSEARCH;
49
50int
51sbread(struct uufsd *disk)
52{
53	struct fs *fs;
54	int sb, superblock;
55
56	DEBUG(NULL);
57
58	fs = &disk->d_fs;
59	superblock = superblocks[0];
60
61	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
62		if (bread(disk, superblock, disk->d_sb, SBLOCKSIZE) == -1) {
63			disk->d_error = "non-existent or truncated superblock";
64			DEBUG(NULL);
65			return -1;
66		}
67		if (fs->fs_magic == FS_UFS1_MAGIC)
68			disk->d_ufs = 1;
69		if ((fs->fs_magic == FS_UFS2_MAGIC) &&
70		    (fs->fs_sblockloc == superblock))
71			disk->d_ufs = 2;
72		if ((fs->fs_bsize <= MAXBSIZE) &&
73		    (fs->fs_bsize >= sizeof(*fs))) {
74			if (disk->d_ufs)
75				break;
76		}
77		disk->d_ufs = 0;
78	}
79	if (superblock == -1 || disk->d_ufs == 0) {
80		/*
81		 * Other error cases will result in errno being set, here we
82		 * must set it to indicate no superblock could be found with
83		 * which to associate this disk/filesystem.
84		 */
85		DEBUG("no superblock found");
86		disk->d_error = "no superblock found";
87		errno = ENOENT;
88		return -1;
89	}
90	disk->d_bsize = fs->fs_fsize / fsbtodb(fs, 1);
91	disk->d_sblock = superblock / disk->d_bsize;
92	return 0;
93}
94
95int
96sbwrite(struct uufsd *disk, int all)
97{
98	struct fs *fs;
99	int i, rofd;
100
101	DEBUG(NULL);
102
103	fs = &disk->d_fs;
104
105	rofd = disk->d_fd;
106	disk->d_fd = open(disk->d_name, O_WRONLY);
107	if (disk->d_fd < 0) {
108		DEBUG("open");
109		disk->d_error = "failed to open disk";
110		return -1;
111	}
112	if (bwrite(disk, disk->d_sblock, fs, SBLOCKSIZE) == -1) {
113		DEBUG(NULL);
114		disk->d_error = "failed to write superblock";
115		return -1;
116	}
117	if (all) {
118		for (i = 0; i < fs->fs_ncg; i++)
119			if (bwrite(disk, fsbtodb(fs, cgsblock(fs, i)),
120			    fs, SBLOCKSIZE) == -1) {
121				DEBUG(NULL);
122				disk->d_error = "failed to update a superblock";
123				return -1;
124			}
125	}
126	close(disk->d_fd);
127	disk->d_fd = rofd;
128	return 0;
129}
130