superblock 0.2.1

A script written in Python 2 to analyze the superblock of an ext2/ext3 formatted file.

A script written in Python 2 to analyze the superblock of an ext2/ext3 formatted file.

Such a file can be created as follows:

$ dd count=4096 if=/dev/zero of=filesystem.ext3
$ sudo mkfs.ext3 filesystem.ext3

It can be mounted with

$ sudo mount -t ext3 -o loop filesystem.ext3 /mnt/mountpoint

Install

You can either download superblock.py file and use it directly, or install the superblock command via pip:

$ sudo pip install superblock

Usage

$ superblock [dump|analyze] <filename>

License

MIT License, see LICENSE file.

Examples

Dump

Printing superblock (bytes 1024-1535) of file fs.ext2.

                     HEX                       ASCII
 1:  40000000 00020000 19000000 e2010000  @...............
 2:  32000000 01000000 00000000 00000000  2...............
 3:  00200000 00200000 40000000 82bad550  . ... ..@......P
 4:  c4bcd550 0200ffff 53ef0100 01000000  ...P....S.......
 5:  968bd550 00000000 00000000 01000000  ...P............
 6:  00000000 0b000000 80000000 38000000  ............8...
 7:  02000000 01000000 dc0cb51b 2ab54967  ............*.Ig
 8:  8e602492 87974d10 65787065 72696d5f  .`$...M.experim_
 9:  65787432 00000000 2f686f6d 652f6461  ext2..../home/da
10:  6e696c6f 2f50726f 6a656374 732f7375  nilo/Projects/su
11:  70657262 6c6f636b 2f6d6e74 00000000  perblock/mnt....
12:  00000000 00000000 00000000 00000000  ................
13:  00000000 00000000 00000000 00000100  ................
14:  00000000 00000000 00000000 00000000  ................
15:  00000000 00000000 00000000 ff27f89c  .............'..
16:  b5cb41d1 987de848 6b3e81ba 01000000  ..A..}.Hk>......
17:  0c000000 00000000 968bd550 00000000  ...........P....
18:  00000000 00000000 00000000 00000000  ................
19:  00000000 00000000 00000000 00000000  ................
20:  00000000 00000000 00000000 00000000  ................
21:  00000000 00000000 00000000 00000000  ................
22:  00000000 00000000 00000000 00000000  ................
23:  01000000 00000000 00000000 00000000  ................
24:  00000000 00000000 00000000 00000000  ................
25:  00000000 00000000 00000000 00000000  ................
26:  00000000 00000000 00000000 00000000  ................
27:  00000000 00000000 00000000 00000000  ................
28:  00000000 00000000 00000000 00000000  ................
29:  00000000 00000000 00000000 00000000  ................
30:  00000000 00000000 00000000 00000000  ................
31:  00000000 00000000 00000000 00000000  ................
32:  00000000 00000000 00000000 00000000  ................

Analyze

Analyzing superblock (bytes 1024-1535) of file fs.ext2.

Total number of inodes: 64
Filesystem size in blocks: 512
Number of reserved blocks: 25
Free blocks counter: 482
Free inodes counter: 50
Number of first block: 1
Block size: 0 (1024 Byte)
Fragment size: 0
Number blocks per group: 8192
Number fragments per group: 8192
Number inodes per group: 64
Number of block groups: 1
Time of last mount: 1356184194 (2012-12-22 14:49:54)
Time of last write: 1356184772 (2012-12-22 14:59:32)
Mount operations counter: 2
Number of mount operations before check: 65535
Magic signature: 0XEF53
Status flag: 1
Behavior when detecting errors: 1
Minor revision level: 0
Time of last check: 1356172182 (2012-12-22 11:29:42)
Time between checks: 0
OS Filesystem created: 0
Revision level: 1
Default user ID for reserved blocks: 0
Default group ID for reserved blocks: 0
Number first nonreserved inode: 11
Size of on-disk inode structure: 128
Block group number of this superblock: 0
Compatible features bitmap: 111000 (ext_attr resize_ino dir_index)
Incompatible features bitmap: 00010 (filetype)
Read-only features bitmap: 001 (sparse_super)
128-bit filesystem identifier: dc0cb51b-2ab5-4967-8e60-249287974d10
Volume name: experim_ext2
Path of last mount point: /home/danilo/Projects/superblock/mnt
Compression Algorithm: 00000 (none)
Number of blocks to preallocate: 0
Number of blocks to preallocate for directories: 0
Journal UUID: 00000000-0000-0000-0000-000000000000
Journal inode number: 0
Journal device number: 0
Journal last orphan: 0
Hash seed: 2633508863 3510750133 1223196056 3129032299
Hash version: 1
Default mount options: 01100 (xattr_user acl)
First meta block group ID: 0

Resources

• The Second Extended File System

• /usr/include/ext2fs/ext2_fs.h