Re: 2.4.22-pre lockups (now decoded oops for pre10)

Oleg Drokin
2003-08-07T05:35:49Z

Hello!

On Thu, Aug 07, 2003 at 04:14:40AM +0200, Stephan von Krawczynski wrote:

> Unable to handle kernel NULL pointer dereference at virtual address 00000004

Hm NULL pointer in j_dirty_buffers list. This cannot happen, basically.
This is a cyclically linked list of buffers. And we add stuff to it via standard
functions, so the linkage happens by itself.

> Trace; c0183ef5 <reiserfs_sync_file+65/d0>
> Trace; f8c84fc8 <[nfsd]nfsd_sync+78/d0>
> Code; c0145060 <fsync_buffers_list+50/1b0>
> 00000000 <_EIP>:
> Code; c0145060 <fsync_buffers_list+50/1b0> <=====
> 0: 89 50 04 mov %edx,0x4(%eax) <=====

> As you can see reiserfs seems involved. Regarding reiserfs and my last postings
> I can assure you that all reiserfs partitions were checked via reiserfsck right
> before installation of rc1 - as Oleg advised - and found:
> "Comparing bitmaps.. vpf-10640: The on-disk and the correct bitmaps differs"

That might explain your prior "freeing already free block" messages.

> I was told to use --fix-fixable option which I did and it indeed fixed the
> problem. Trying reiserfsck after that found no errors any more. So I see no
> chance that corrupt data on the media (through former crashes) is responsible
> for this one. Hint: spelling in reiserfsck should be checked ;-)

Yes, but how the condition that triggered the oops have appeared is totally unclear for me.

Bye,
Oleg