1 /*
2  * unused.c --- quick and dirty unused space dumper
3  *
4  * Copyright (C) 1997 Theodore Ts'o.  This file may be redistributed
5  * under the terms of the GNU Public License.
6  */
7 
8 #include "config.h"
9 #include <stdio.h>
10 #include <unistd.h>
11 #include <stdlib.h>
12 #include <ctype.h>
13 #include <string.h>
14 #include <time.h>
15 #ifdef HAVE_ERRNO_H
16 #include <errno.h>
17 #endif
18 #include <sys/types.h>
19 #ifdef HAVE_GETOPT_H
20 #include <getopt.h>
21 #else
22 extern int optind;
23 extern char *optarg;
24 #endif
25 
26 #include "debugfs.h"
27 
28 void do_dump_unused(int argc EXT2FS_ATTR((unused)), char **argv)
29 {
30 	blk64_t		blk;
31 	unsigned char	buf[EXT2_MAX_BLOCK_SIZE];
32 	unsigned int	i;
33 	errcode_t	retval;
34 
35 	if (common_args_process(argc, argv, 1, 1,
36 				"dump_unused", "", 0))
37 		return;
38 
39 	for (blk=current_fs->super->s_first_data_block;
40 	     blk < ext2fs_blocks_count(current_fs->super); blk++) {
41 		if (ext2fs_test_block_bitmap2(current_fs->block_map,blk))
42 			continue;
43 		retval = io_channel_read_blk64(current_fs->io, blk, 1, buf);
44 		if (retval) {
45 			com_err(argv[0], retval, "While reading block\n");
46 			return;
47 		}
48 		for (i=0; i < current_fs->blocksize; i++)
49 			if (buf[i])
50 				break;
51 		if (i >= current_fs->blocksize)
52 			continue;
53 		printf("\nUnused block %llu contains non-zero data:\n\n",
54 		       blk);
55 		for (i=0; i < current_fs->blocksize; i++)
56 			fputc(buf[i], stdout);
57 	}
58 }
59