[OpenAFS] OpenAFS 1.2.7 on Linux 2.2.19 kernel: oops with 'increase -stat parameter on afsd(VLRU cycle)' again?

[Derrick J Brashear]

On Thu, 14 Nov 2002, Rainer Toebbicke wrote:

> Hello all,
> 
> I've got the feeling I've seen this mentioned recently but somehow can't find 
> it now:
> 
> We upgraded a couple hundred RedHat 6.2 kernel 2.2.19 from OpenAfs 1.2.3+ to 
> OpenAFS 1.2.7 and now run into something that looks like triggered through an 
> 'rsync' the system crashes with
> 
> Nov 12 02:12:02 lxplus026 kernel: Increase -stat parameter of afsd(VLRU 
> cycle?)<1>Unable to handle kernel paging request at vi\rtual address ffffffff
> 
> We did NOT see this under 1.2.3.  The '-stat' is set to 10000 already!

A modification of afs_TryFlushDcacheChildren in src/afs/afs_vcache.c was
made to prevent a race which caused an oops in dput(), and it may be the
cause of this. Chas Williams and I worked out something better that's in
the head which should be pulled up for 1.2.8, which is comparable to
shrink_dcache_parent but adapted for our purposes.