[reiserfs-list] RE: [OpenAFS-devel] weird issue with reiserfs on 2.4.3 and openaf s

[Chris Mason]

On Wednesday, April 11, 2001 09:39:43 AM -0500 "Neulinger, Nathan"
<nneul@umr.edu> wrote:

> I wonder, would the workaround that we came up with for the performance
> issue with 2.2 help here? i.e. opening the files with afsd prior to doing
> the iget in the kernel?
> 
> In that case it was just for performance to eliminate the bad fallback. In
> this case, would it still eliminate the bad fallback? Or would it just
> eliminate the panic most of the time and possibly it would come back in
> the case where the inode cache got flushed?
> 

Sorry, my memory of the workaround isn't that great.  This will always work:
open(file)
iget(file's inode)
close(file)

This will work most of the time, but has a window where the inode can go
out of cache:
open(file)
close(file)
iget(file's inode)

> Can you get me some more details about what would need to be stored/etc.
> Is there any way to code that in a reasonably filesystem independent
> manner? I.e. I'd hate to have afsd/libafs have to be configured
> differently for different filesystems, yuck.

As far as I know, none of the current filesystems need more than 64 bits of
data to find a given inode.  If AFS needs things like a generation number,
or the ability to also find the paren't inode (like NFS does), things start
getting more complicated.

The best thing is probably to work with the NFS guys on something you both
can use.

-chris