FS corruption? bogus i_mode

[Rajaraman Ramanarayanan]

Hello,
I am doing some testing on a PXA270 based processor (on a single 
board computer) which makes the processor vulnerable to bit flips. One
such bit flips seems to have corrupted the file system.

The debug port on the board (it is a single board computer) had the 
following message when i think the FS corruption occured :

<7>init_special_inode: bogus i_mode (33061)

init_special_inode: bogus i_mode (30071)

init_special_inode: bogus i_mode (34065)

init_special_inode: bogus i_mode (30061)

init_special_inode: bogus i_mode (33061)

init_special_inode: bogus i_mode (30071)


After this happened, directories like bin etc. were corrupted ( I am 
pasting the screen shot of ll commands that i did) which meant that i 
could not start the board again using the same FS (I had to re install the 
root file system on the hard drive).

My question is what error could have caused a file system corruption like 
this. Is it possible to trace and analyze if i have the whole FS backed 
up? The OS was debian linux. I hope the question is clear and the given 
information is useful enough to make some comments. Here is the screen 
shot of the ll commands for 2 of the directories:
(The total space in the partition was 4GB)
*************************************************************************
segrith.cse.psu.edu 66% du -khs bin
426G    bin
segrith.cse.psu.edu 67% ll
total 446404348
cr-Sr-S--- 8240 959265076 876099129 32, 50 Oct  2  1997 bin
drwxr-xr-x    2 root      root        4096 Sep 30  2005 boot
drwxr-xr-x    6 root      root       24576 Oct 10 15:29 dev
drwxr-xr-x   61 root      root        4096 Oct 10 15:32 etc
drwxr-xr-x    2 root      root        4096 Sep 30  2005 home
drwxr-xr-x    2 root      root        4096 Dec 31  1969 initrd
drwxr-xr-x    9 root      root        4096 Jan 12  2006 lib
drwxr-xr-x    2 root      root       16384 Dec 31  1969 lost+found
drwxr-xr-x    4 root      root        4096 Dec 19  2005 media
drwxr-xr-x    8 root      root        4096 Apr 26 15:39 mnt
drwxr-xr-x    3 root      root        4096 Dec 19  2005 opt
dr-xr-xr-x    2 root      root        4096 Dec 31  1969 proc
drwxr-xr-x    4 root      root        4096 Oct  9 23:10 root
drwxr-xr-x    2 root      root        4096 May  1 11:38 sbin
drwxr-xr-x    2 root      root        4096 Jan 12  2006 selinux
drwxr-xr-x    2 root      root        4096 Dec 31  1969 srv
drwxr-xr-x    2 root      root        4096 Dec 31  1969 sys
drwxrwxrwt    4 root      root        4096 Oct 10 15:29 tmp
drwxr-xr-x   12 root      root        4096 Dec 19  2005 usr
drwxr-xr-x   13 root      root        4096 Dec 19  2005 var
segrith.cse.psu.edu 68% cd root/samplecodes/test7/
segrith.cse.psu.edu 69% du -khs *
426G    a.out
0       err.out
434G    matrix_a
458G    matrix_b
394G    matrix_c
426G    matrix_d
434G    matrix_e
394G    matrix_f
segrith.cse.psu.edu 70% ll
total 3107434033
?---rw---x 11552 892546336 959789109 943207220 Dec 28  1993 a.out
-rw-r--r--     1 root      root              0 Oct 10 15:09 err.out
?---rwS--t 13869 909522483 540549173 926166304 Dec 28  1993 matrix_a
?--Srw-r-x 11552 943140128 757084720 808726580 Dec 28  1993 matrix_b
?---rwx--x  8246 842276912 540030005 859124013 Feb 11  1987 matrix_c
?---rw---x 11552 892546336 959789109 943207220 Dec 28  1993 matrix_d
?---rwS--t 13869 909522483 540549173 926166304 Dec 28  1993 matrix_e
?---rwx--x  8246 842276912 540030005 859124013 Feb 11  1987 matrix_f
segrith.cse.psu.edu 71%
************************************************************************
Thank you!
Sincerely,
Rajaraman