[OpenAFS-devel] Kernel panic with openafs 1.4.0

[Jeffrey Hutzelman]

On Thursday, August 24, 2006 01:14:11 PM +0200 Harald Barth 
<haba@pdc.kth.se> wrote:

>
>> Today I've encountered the following kernel panic with openafs 1.4.0 on
>> a Scientific Linux 4 system (RedHat Enterprise 4 compatible). Will this
>> be fixed in 1.4.2?
>
> That's a bit difficult to tell before we know why it broke.
> I have not seen this particular bug before, someone else
> might.
>
> Let me see... We are in afs_NewVCache() and call osi_Panic().
> Unfortunately osi_Panic() did not write the message string,
> but only called BUG(). (Can we fix that for the future?)

There's nothing to fix.  osi_Panic _does_ print out the message string, but 
necessarily does so _before_ it calls BUG().  Which means that users 
habitually don't actually copy the message when sending in a report. 
Fixing this would require changes to Linux to allow something calling BUG 
to include a message that gets included _below_ the "cut here" line.


> Normally afs_NewVCache() works, so why did it not work for
> you here?
>
> So the standard questions are:

... all the ones you mentioned, plus "what were the last few messages right 
_before_ the 'cut here' line.


Also, the standard cause of NewVCache failing in 1.4.0 on a Linux 2.6 
system is that the default parameters include only 300 vcache entries, 
which is nowhere near enough.

-- Jeff