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+/*
+ * findsuper --- quick hacked up program to find ext2 superblocks.
+ *
+ * This is a hack, and really shouldn't be installed anywhere. If you
+ * need a program which does this sort of functionality, please try
+ * using gpart program.
+ *
+ * Portions Copyright 1998-2000, Theodore Ts'o.
+ *
+ * Well, here's my linux version of findsuper.
+ * I'm sure you coulda done it faster. :)
+ * IMHO there isn't as much interesting data to print in the
+ * linux superblock as there is in the SunOS superblock--disk geometry is
+ * not there...and linux seems to update the dates in all the superblocks.
+ * SunOS doesn't ever touch the backup superblocks after the fs is created,
+ * as far as I can tell, so the date is more interesting IMHO and certainly
+ * marks which superblocks are backup ones.
+ *
+ * I wanted to add msdos support, but I couldn't make heads or tails
+ * of the kernel include files to find anything I could look for in msdos.
+ *
+ * Reading every block of a Sun partition is fairly quick. Doing the
+ * same under linux (slower hardware I suppose) just isn't the same.
+ * It might be more useful to default to reading the first (second?) block
+ * on each cyl; however, if the disk geometry is wrong, this is useless.
+ * But ya could still get the cyl size to print the numbers as cyls instead
+ * of blocks...
+ *
+ * run this as (for example)
+ * findsuper /dev/hda
+ * findsuper /dev/hda 437760 1024 (my disk has cyls of 855*512)
+ *
+ * I suppose the next step is to figure out a way to determine if
+ * the block found is the first superblock somehow, and if so, build
+ * a partition table from the superblocks found... but this is still
+ * useful as is.
+ *
+ * Steve
+ * ssd@nevets.oau.org
+ * ssd@mae.engr.ucf.edu
+ *
+ * Additional notes by Andreas Dilger <adilger@turbolinux.com>:
+ * - fixed to support > 2G devices by using lseek64
+ * - add reliability checking for the superblock to avoid random garbage
+ * - add adaptive progress meter
+ *
+ * It _should_ also handle signals and tell you the ending block, so
+ * that you can resume at a later time, but it doesn't yet...
+ *
+ * Note that gpart does not appear to find all superblocks that aren't aligned
+ * with the start of a possible partition, so it is not useful in systems
+ * with LVM or similar setups which don't use fat partition alignment.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+/*
+ * Documentation addendum added by Andreas dwguest@win.tue.nl/aeb@cwi.nl
+ *
+ * The program findsuper is a utility that scans a disk and finds
+ * copies of ext2 superblocks (by checking for the ext2 signature).
+ *
+ * For each superblock found, it prints the offset in bytes, the
+ * offset in 1024-byte blocks, the size of the ext2 partition in fs
+ * blocks, the filesystem blocksize (in bytes), the block group number
+ * (always 0 for older ext2 systems), and a timestamp (s_mtime).
+ *
+ * This program can be used to retrieve partitions that have been
+ * lost. The superblock for block group 0 is found 1 block (2
+ * sectors) after the partition start.
+ *
+ * For new systems that have a block group number in the superblock it
+ * is immediately clear which superblock is the first of a partition.
+ * For old systems where no group numbers are given, the first
+ * superblock can be recognized by the timestamp: all superblock
+ * copies have the creation time in s_mtime, except the first, which
+ * has the last time e2fsck or tune2fs wrote to the filesystem.
+ *
+ */
+
+#define _FILE_OFFSET_BITS 64
+
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+
+#include "ext2fs/ext2_fs.h"
+#include "ext2fs/ext2fs.h"
+#include "support/nls-enable.h"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define WHY(fmt, arg...) { printf("\r%Ld: " fmt, sk, ##arg) ; continue; }
+#else
+#define WHY(fmt, arg...) { continue; }
+#endif
+
+static void usage(void)
+{
+ fprintf(stderr,
+ _("Usage: findsuper device [skipbytes [startkb]]\n"));
+ exit(1);
+}
+
+
+int main(int argc, char *argv[])
+{
+ int skiprate=512; /* one sector */
+ ext2_loff_t sk=0, skl=0;
+ int fd;
+ char *s;
+ time_t tm, last = time(0);
+ ext2_loff_t interval = 1024 * 1024;
+ int c, print_jnl_copies = 0;
+ const char * device_name;
+ struct ext2_super_block ext2;
+ /* interesting fields: EXT2_SUPER_MAGIC
+ * s_blocks_count s_log_block_size s_mtime s_magic s_lastcheck */
+
+#ifdef ENABLE_NLS
+ setlocale(LC_MESSAGES, "");
+ setlocale(LC_CTYPE, "");
+ bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
+ textdomain(NLS_CAT_NAME);
+ set_com_err_gettext(gettext);
+#endif
+
+ while ((c = getopt (argc, argv, "j")) != EOF) {
+ switch (c) {
+ case 'j':
+ print_jnl_copies++;
+ break;
+ default:
+ usage();
+ }
+ }
+
+ if (optind == argc)
+ usage();
+
+ device_name = argv[optind++];
+
+ if (optind < argc) {
+ skiprate = strtol(argv[optind], &s, 0);
+ if (s == argv[optind]) {
+ fprintf(stderr,_("skipbytes should be a number, not %s\n"), s);
+ exit(1);
+ }
+ optind++;
+ }
+ if (skiprate & 0x1ff) {
+ fprintf(stderr,
+ _("skipbytes must be a multiple of the sector size\n"));
+ exit(2);
+ }
+ if (optind < argc) {
+ sk = skl = strtoll(argv[optind], &s, 0) << 10;
+ if (s == argv[optind]) {
+ fprintf(stderr,
+ _("startkb should be a number, not %s\n"), s);
+ exit(1);
+ }
+ optind++;
+ }
+ if (sk < 0) {
+ fprintf(stderr, _("startkb should be positive, not %llu\n"),sk);
+ exit(1);
+ }
+
+ fd = open(device_name, O_RDONLY);
+ if (fd < 0) {
+ perror(device_name);
+ exit(1);
+ }
+
+ /* Now, go looking for the superblock! */
+ printf(_("starting at %llu, with %u byte increments\n"), sk, skiprate);
+ if (print_jnl_copies)
+ printf(_("[*] probably superblock written in the ext3 "
+ "journal superblock,\n\tso start/end/grp wrong\n"));
+ printf(_("byte_offset byte_start byte_end fs_blocks blksz grp mkfs/mount_time sb_uuid label\n"));
+ for (; lseek64(fd, sk, SEEK_SET) != -1 &&
+ read(fd, &ext2, 512) == 512; sk += skiprate) {
+ static unsigned char last_uuid[16] = "blah";
+ unsigned long long bsize, grpsize;
+ int jnl_copy, sb_offset;
+
+ if (sk && !(sk & (interval - 1))) {
+ time_t now, diff;
+
+ now = time(0);
+ diff = now - last;
+
+ if (diff > 0) {
+ s = ctime(&now);
+ s[24] = 0;
+ printf("\r%11Lu: %8LukB/s @ %s", sk,
+ (((sk - skl)) / diff) >> 10, s);
+ fflush(stdout);
+ }
+ if (diff < 5)
+ interval <<= 1;
+ else if (diff > 20)
+ interval >>= 1;
+ last = now;
+ skl = sk;
+ }
+ if (ext2.s_magic != EXT2_SUPER_MAGIC)
+ continue;
+ if (ext2.s_log_block_size > 6)
+ WHY("log block size > 6 (%u)\n", ext2.s_log_block_size);
+ if (ext2fs_r_blocks_count(&ext2) > ext2fs_blocks_count(&ext2))
+ WHY("r_blocks_count > blocks_count (%u > %u)\n",
+ ext2fs_r_blocks_count(&ext2),
+ ext2fs_blocks_count(&ext2));
+ if (ext2fs_free_blocks_count(&ext2) > ext2fs_blocks_count(&ext2))
+ WHY("free_blocks_count > blocks_count\n (%u > %u)\n",
+ ext2fs_free_blocks_count(&ext2),
+ ext2fs_blocks_count(&ext2));
+ if (ext2.s_free_inodes_count > ext2.s_inodes_count)
+ WHY("free_inodes_count > inodes_count (%u > %u)\n",
+ ext2.s_free_inodes_count, ext2.s_inodes_count);
+
+ if (ext2.s_mkfs_time != 0)
+ tm = ext2.s_mkfs_time;
+ else
+ tm = ext2.s_mtime;
+ s = ctime(&tm);
+ s[24] = 0;
+ bsize = 1 << (ext2.s_log_block_size + 10);
+ grpsize = bsize * ext2.s_blocks_per_group;
+ if (memcmp(ext2.s_uuid, last_uuid, sizeof(last_uuid)) == 0 &&
+ ext2.s_rev_level > 0 && ext2.s_block_group_nr == 0) {
+ jnl_copy = 1;
+ } else {
+ jnl_copy = 0;
+ memcpy(last_uuid, ext2.s_uuid, sizeof(last_uuid));
+ }
+ if (ext2.s_block_group_nr == 0 || bsize == 1024)
+ sb_offset = 1024;
+ else
+ sb_offset = 0;
+ if (jnl_copy && !print_jnl_copies)
+ continue;
+ printf("\r%11Lu %11Lu%s %11Lu%s %9u %5Lu %4u%s %s %02x%02x%02x%02x %.*s\n",
+ sk, sk - ext2.s_block_group_nr * grpsize - sb_offset,
+ jnl_copy ? "*":" ",
+ sk + ext2fs_blocks_count(&ext2) * bsize -
+ ext2.s_block_group_nr * grpsize - sb_offset,
+ jnl_copy ? "*" : " ", ext2fs_blocks_count(&ext2), bsize,
+ ext2.s_block_group_nr, jnl_copy ? "*" : " ", s,
+ ext2.s_uuid[0], ext2.s_uuid[1],
+ ext2.s_uuid[2], ext2.s_uuid[3],
+ EXT2_LEN_STR(ext2.s_volume_name));
+ }
+ printf(_("\n%11Lu: finished with errno %d\n"), sk, errno);
+ close(fd);
+
+ return errno;
+}