# gdb /opt/e2fsprogs/sbin/e2fsck 
GNU gdb 6.8-debian
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i486-linux-gnu"...
(gdb) run -v /mnt/cifs/backup/sdb2.img
Starting program: /opt/e2fsprogs/sbin/e2fsck -v /mnt/cifs/backup/sdb2.img
e2fsck 1.41-WIP (27-Apr-2008)
Superblock has an invalid ext3 journal (inode 8).
Clear<y>? yes

*** ext3 journal has been deleted - filesystem is now ext2 only ***

The filesystem size (according to the superblock) is 9371600 blocks
The physical size of the device is 9338882 blocks
Either the superblock or the partition table is likely to be corrupt!
Abort<y>? no

Resize inode not valid.  Recreate<y>? yes

/mnt/cifs/backup/sdb2.img contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Error while iterating over blocks in inode 1: Operation not supported for inodes containing extents
Recreate journal to make the filesystem ext3 again?
Fix<y>? yes

Creating journal (32768 blocks):  Done.

*** journal has been re-created - filesystem is now ext3 again ***
e2fsck: aborted

Program exited with code 010.
(gdb) bt full
No stack.
(gdb) quit