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74a74d22 TT |
1 | /* |
2 | * findsuper --- quick hacked up program to find ext2 superblocks. | |
3 | * | |
4 | * This is a hack, and really shouldn't be installed anywhere. If you | |
5 | * need a program which does this sort of functionality, please try | |
6 | * using gpart program. | |
7 | * | |
8 | * Portions Copyright 1998-2000, Theodore Ts'o. | |
9 | * | |
74a74d22 | 10 | * Well, here's my linux version of findsuper. |
7f88b043 TT |
11 | * I'm sure you coulda done it faster. :) |
12 | * IMHO there isn't as much interesting data to print in the | |
13 | * linux superblock as there is in the SunOS superblock--disk geometry is | |
14 | * not there...and linux seems to update the dates in all the superblocks. | |
15 | * SunOS doesn't ever touch the backup superblocks after the fs is created, | |
16 | * as far as I can tell, so the date is more interesting IMHO and certainly | |
17 | * marks which superblocks are backup ones. | |
18 | * | |
7f88b043 TT |
19 | * I wanted to add msdos support, but I couldn't make heads or tails |
20 | * of the kernel include files to find anything I could look for in msdos. | |
21 | * | |
22 | * Reading every block of a Sun partition is fairly quick. Doing the | |
23 | * same under linux (slower hardware I suppose) just isn't the same. | |
24 | * It might be more useful to default to reading the first (second?) block | |
25 | * on each cyl; however, if the disk geometry is wrong, this is useless. | |
26 | * But ya could still get the cyl size to print the numbers as cyls instead | |
27 | * of blocks... | |
28 | * | |
29 | * run this as (for example) | |
30 | * findsuper /dev/hda | |
31 | * findsuper /dev/hda 437760 1024 (my disk has cyls of 855*512) | |
32 | * | |
33 | * I suppose the next step is to figgure out a way to determine if | |
34 | * the block found is the first superblock somehow, and if so, build | |
35 | * a partition table from the superblocks found... but this is still | |
36 | * useful as is. | |
37 | * | |
38 | * Steve | |
39 | * ssd@nevets.oau.org | |
40 | * ssd@mae.engr.ucf.edu | |
d6903ecc AD |
41 | * |
42 | * Additional notes by Andreas Dilger <adilger@turbolinux.com>: | |
43 | * - fixed to support > 2G devices by using lseek64 | |
44 | * - add reliability checking for the superblock to avoid random garbage | |
45 | * - add adaptive progress meter | |
46 | * | |
47 | * It _should_ also handle signals and tell you the ending block, so | |
48 | * that you can resume at a later time, but it doesn't yet... | |
49 | * | |
50 | * Note that gpart does not appear to find all superblocks that aren't aligned | |
51 | * with the start of a possible partition, so it is not useful in systems | |
52 | * with LVM or similar setups which don't use fat partition alignment. | |
16fa86b9 TT |
53 | * |
54 | * %Begin-Header% | |
55 | * This file may be redistributed under the terms of the GNU Public | |
56 | * License. | |
57 | * %End-Header% | |
7f88b043 TT |
58 | */ |
59 | ||
e2423cc0 TT |
60 | /* |
61 | * Documentation addendum added by Andreas dwguest@win.tue.nl/aeb@cwi.nl | |
62 | * | |
63 | * The program findsuper is a utility that scans a disk and finds | |
bb145b01 | 64 | * copies of ext2 superblocks (by checking for the ext2 signature). |
e2423cc0 TT |
65 | * |
66 | * For each superblock found, it prints the offset in bytes, the | |
bb145b01 | 67 | * offset in 1024-byte blocks, the size of the ext2 partition in fs |
d6903ecc AD |
68 | * blocks, the filesystem blocksize (in bytes), the block group number |
69 | * (always 0 for older ext2 systems), and a timestamp (s_mtime). | |
e2423cc0 TT |
70 | * |
71 | * This program can be used to retrieve partitions that have been | |
72 | * lost. The superblock for block group 0 is found 1 block (2 | |
73 | * sectors) after the partition start. | |
74 | * | |
75 | * For new systems that have a block group number in the superblock it | |
76 | * is immediately clear which superblock is the first of a partition. | |
77 | * For old systems where no group numbers are given, the first | |
78 | * superblock can be recognised by the timestamp: all superblock | |
79 | * copies have the creation time in s_mtime, except the first, which | |
80 | * has the last time e2fsck or tune2fs wrote to the filesystem. | |
81 | * | |
82 | */ | |
83 | ||
d6903ecc | 84 | #define _FILE_OFFSET_BITS 64 |
e2423cc0 | 85 | |
7f88b043 TT |
86 | #include <stdio.h> |
87 | #include <stdlib.h> | |
d6903ecc AD |
88 | #include <string.h> |
89 | #include <unistd.h> | |
90 | #include <errno.h> | |
91 | #include <fcntl.h> | |
7f88b043 TT |
92 | #include <time.h> |
93 | ||
54c637d4 | 94 | #include "ext2fs/ext2_fs.h" |
d9c56d3c | 95 | #include "nls-enable.h" |
7f88b043 | 96 | |
d6903ecc AD |
97 | #undef DEBUG |
98 | ||
99 | #ifdef DEBUG | |
100 | #define WHY(fmt, arg...) { printf("\r%Ld: " fmt, sk, ##arg) ; continue; } | |
101 | #else | |
102 | #define WHY(fmt, arg...) { continue; } | |
103 | #endif | |
7f88b043 | 104 | |
d6903ecc | 105 | int main(int argc, char *argv[]) |
7f88b043 | 106 | { |
19c78dc0 | 107 | int skiprate=512; /* one sector */ |
d6903ecc AD |
108 | loff_t sk=0, skl=0; |
109 | int fd; | |
19c78dc0 | 110 | char *s; |
d6903ecc AD |
111 | time_t tm, last = time(0); |
112 | loff_t interval = 1024 * 1024; | |
7f88b043 | 113 | |
19c78dc0 TT |
114 | struct ext2_super_block ext2; |
115 | /* interesting fields: EXT2_SUPER_MAGIC | |
116 | * s_blocks_count s_log_block_size s_mtime s_magic s_lastcheck */ | |
d9c56d3c TT |
117 | |
118 | #ifdef ENABLE_NLS | |
119 | setlocale(LC_MESSAGES, ""); | |
14308a53 | 120 | setlocale(LC_CTYPE, ""); |
d9c56d3c TT |
121 | bindtextdomain(NLS_CAT_NAME, LOCALEDIR); |
122 | textdomain(NLS_CAT_NAME); | |
123 | #endif | |
19c78dc0 TT |
124 | if (argc<2) { |
125 | fprintf(stderr, | |
d6903ecc | 126 | _("Usage: findsuper device [skipbytes [startkb]]\n")); |
19c78dc0 TT |
127 | exit(1); |
128 | } | |
129 | if (argc>2) | |
d6903ecc AD |
130 | skiprate = strtol(argv[2], &s, 0); |
131 | if (s == argv[2]) { | |
ddc32a04 | 132 | fprintf(stderr,_("skipbytes should be a number, not %s\n"), s); |
d6903ecc AD |
133 | exit(1); |
134 | } | |
135 | if (skiprate & 0x1ff) { | |
19c78dc0 | 136 | fprintf(stderr, |
d6903ecc | 137 | _("skipbytes must be a multiple of the sector size\n")); |
19c78dc0 TT |
138 | exit(2); |
139 | } | |
140 | if (argc>3) | |
d6903ecc AD |
141 | sk = skl = strtoll(argv[3], &s, 0) << 10; |
142 | if (s == argv[3]) { | |
143 | fprintf(stderr,_("startkb should be a number, not %s\n"), s); | |
144 | exit(1); | |
145 | } | |
146 | if (sk < 0) { | |
147 | fprintf(stderr,_("startkb should be positive, not %Ld\n"), sk); | |
19c78dc0 TT |
148 | exit(1); |
149 | } | |
d6903ecc AD |
150 | fd = open(argv[1], O_RDONLY); |
151 | if (fd < 0) { | |
19c78dc0 TT |
152 | perror(argv[1]); |
153 | exit(1); | |
154 | } | |
7f88b043 | 155 | |
598ff014 | 156 | /* Now, go looking for the superblock! */ |
d6903ecc AD |
157 | printf(_("starting at %Ld, with %d byte increments\n"), sk, skiprate); |
158 | printf(_(" thisoff block fs_blk_sz blksz grp last_mount\n")); | |
159 | for (; lseek64(fd, sk, SEEK_SET) != -1 && | |
160 | read(fd, &ext2, 512) == 512; sk += skiprate) { | |
161 | ||
162 | if (sk && !(sk & (interval - 1))) { | |
163 | time_t now, diff; | |
164 | ||
165 | now = time(0); | |
166 | diff = now - last; | |
167 | ||
168 | if (diff > 0) { | |
169 | s = ctime(&now); | |
170 | s[24] = 0; | |
171 | printf("\r%14Ld: %8LdkB/s @ %s", sk, | |
172 | (((sk - skl)) / diff) >> 10, s); | |
173 | fflush(stdout); | |
174 | } | |
175 | if (diff < 5) | |
176 | interval <<= 1; | |
177 | else if (diff > 20) | |
178 | interval >>= 1; | |
179 | last = now; | |
180 | skl = sk; | |
19c78dc0 | 181 | } |
e2423cc0 TT |
182 | if (ext2.s_magic != EXT2_SUPER_MAGIC) |
183 | continue; | |
d6903ecc | 184 | if (ext2.s_log_block_size > 4) |
8deb80a5 | 185 | WHY("log block size > 4 (%u)\n", ext2.s_log_block_size); |
d6903ecc | 186 | if (ext2.s_r_blocks_count > ext2.s_blocks_count) |
8deb80a5 | 187 | WHY("r_blocks_count > blocks_count (%u > %u)\n", |
d6903ecc AD |
188 | ext2.s_r_blocks_count, ext2.s_blocks_count); |
189 | if (ext2.s_free_blocks_count > ext2.s_blocks_count) | |
8deb80a5 | 190 | WHY("free_blocks_count > blocks_count\n (%u > %u)\n", |
d6903ecc AD |
191 | ext2.s_free_blocks_count, ext2.s_blocks_count); |
192 | if (ext2.s_free_inodes_count > ext2.s_inodes_count) | |
8deb80a5 | 193 | WHY("free_inodes_count > inodes_count (%u > %u)\n", |
d6903ecc AD |
194 | ext2.s_free_inodes_count, ext2.s_inodes_count); |
195 | ||
e2423cc0 TT |
196 | tm = ext2.s_mtime; |
197 | s=ctime(&tm); | |
198 | s[24]=0; | |
d6903ecc AD |
199 | printf("\r%14Ld %9Ld %9d %5d %4d %s\n", |
200 | sk, sk >> 10, ext2.s_blocks_count, | |
201 | 1 << (ext2.s_log_block_size + 10), | |
e2423cc0 | 202 | ext2.s_block_group_nr, s); |
19c78dc0 | 203 | } |
d6903ecc AD |
204 | printf(_("\n%14Ld: finished with errno %d\n"), sk, errno); |
205 | close(fd); | |
206 | ||
207 | return errno; | |
7f88b043 | 208 | } |