Re: XFS latest changes, sb corruption?

[Paul Blazejowski <paul@blazebox.homeip.net>]

Hi Eric,

I have a bug i think...i was able to reproduce the sb corruption after
compiling new kernel.

Updated my xfs tree with todays CVS (no changes) then i generated a diff 
against clean 2.4.18 kernel patched with xfs and jfs patches,did make dep 
then make bzImage followed by make modules...all of these steps went fine.
I rerun /sbin/lilo to update the loader and made a quick boot disk using:
dd if=/dev/sda2 of=/dev/fd0 ibs=1440 count=1 (sda2 is the partition with xfs).
Again there was no crashes or forced shutdowns...rebooted the box and when 
new kernel booted it showed these errors: 

XFS: bad magic number
XFS: SB validate failed
VFS: unable to mount block device on (8,2) or something close.

Again this is on Slackware Linux 8.0 with kernel 2.4.18 and gcc 2.95.3.

This is what xfs_repair shows:

xfs_repair -n /dev/sda2
Phase 1 - find and verify superblock...
bad primary superblock - bad magic number !!!

attempting to find secondary superblock...
.................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................found 
candidate secondary superblock...
verified secondary superblock...
would write modified primary superblock
primary superblock would have been modified.
cannot proceed further in no_modify mode.
exiting now.

I did not make any changes to the fs yet...how would i pull the first few kb 
off of the fs you mentioned earlier? Thanks again for your help.

Regards,

Paul