[reiserfs-list] Re: [OpenAFS-devel] more on the 2.2.18pre17 SMPcpu hog/etc.

[Jeffrey Hutzelman]

On Tue, 5 Dec 2000, Andi Kleen wrote:

> On Mon, Dec 04, 2000 at 07:34:42PM -0500, Jeffrey Hutzelman wrote:
> > > > > copied inode structure looks very fragile and has e.g. caused problems
> > > > > with the suse kernel (which has two fields more than a normal linux 2.2
> > > > > inode)
> > > > 
> > > > It's not as fragile as you might think.  The inode structure doesn't
> > > > change all that frequently, and using symbol versions catches it when
> > > > it does change.  Unfortunately, far too many people use AFS modules
> > > > without symbol versions.  I'm hoping that will begin to change.
> > > 
> > > I know that it breaks here.
> > 
> > Because you try to load a module that is not compatible with your kernel.
> 
> I hacked it now to handle the additional fields, but it is rather ugly.
> 
> > If the modules used symbol versions (I assume your kernels already do),
> > then you'd notice right away.
> 
> SuSE kernels do not use symbol versions. In practice they're causing more
> problems than they solve, mostly because the mangling is not complete 
> enough.

In which case, a SuSE 2.2.17 kernel should not call itself '2.2.17', since
that subverts the only mechanism left to a module to be sure it's being
loaded into the right kernel.