[OpenAFS] kernel panic

[Chris Majewski]

All was happy until, after rebooting this morning, I got this from my kernel:

Starting AFS cache scan...found 0 non-empty cache files (0%%).
Unable to handle kernel NULL pointer dereference at virtual address 00000000
 printing eip:
eb2e6b22
*pde = 00000000
Oops: 0000
CPU: 0
EIP:    0010:[<eb2e6b22>]    Tainted: PF
EFLAGS: 00010283
eax: 00000063   ebx: eb33dccc   ecx: e3dd1f54   edx: d7b2caa0
esi: dc3e0421   edi: 00000000   ebp: e3dd1f54   esp: e3dd1dc8
ds: 0018   es: 0018   ss: 0018
Process afsd (pid: 1074, stackpage=e3dd1000)
Stack: 00000000 eb2e6b14 eb2e6a63 d7b2caa0 00000000 00000000 eb2f23f9 b60b60b7 
May  19  11:14:17  mi  kernel:  00000000  00000001  00001913  e3dd1e8c
3ec91ef9 00000000 eb2e6ac3 eb2e6b14 
       00000000 00000001 eb2f75a0 b60b60b7 eb3466c0 0000000c 00000000 b60b60b7 
Call Trace:    [<eb2e6b14>] [<eb2e6a63>] [<eb2f23f9>] [<eb2e6ac3>] [<eb2e6b14>]
  [<eb2f75a0>] [<eb3466c0>] [<eb2e6ba1>] [<eb2e6b14>] [<eb2e6bc0>] [<eb32fe58>]
  [<eb2e6d76>] [<eb2e831a>] [<eb2e82ab>] [_alloc_pages+22/24] [schedule+762/804] [<eb3226ad>]
  [<eb2e7fe7>] [<eb2e81f9>] [sprintf+20/24] [<eb334e05>] [<eb324dee>] [<eb334e05>]
  [<eb324cda>] [kernel_thread+31/56] [kernel_thread+40/56]

Code: ae 75 08 84 c0 75 f8 31 c0 eb 04 19 c0 0c 01 31 c9 85 c0 75 


I  had started  afsd  with '-verbose-'.  Following  the usual  lengthy
logging of the cache scan, I got this on the console:

, 28, 10)=0 SScall(137, 28, 10)=0 SScall(137, 28, 10)=0 SScall(137, 28, 10)=0 SScall(137, 28, 10)=0 SScall(137, 28, 10)=0 SScall(137, 28, 10)=0 SScall(137, 28, 100)=0 afsd: All AFS daemons started.
afsd: Forking trunc-cache daemon.
afsd: Mounting the AFS root on '/afs', flags: 0.
SScall(137, 28, 3)=0 

Yow, please help.  This is the first time  I've rebooted since getting
OpenAFS working (i've built 1.2.9 from vanilla source).  

I should add that I had just rebuilt my kernel modules (though not the
kernel) to tweak something in the parport driver. During this process,
an old  Debian openafs module  source (/usr/src/modules/openafs) got
rebuilt as well.  However, this  is probably a red herring, because my
/etc/init.d/afs  only makes  reference to  my own  OpenAFS  install in
/usr/local. And, checking the date on /lib/modules/current/fs/openafs.o,
it's something very old. So that module hasn't changed, even if it
were  loaded. Which  it isn't,  because I  cleverly renamed  it before
rebooting. Phew. 

-chris