Re: [PATCH 4/9] pstore: Allow the user to explicitly choose a backend

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Mon, Jul 18, 2011 at 01:58:28PM -0700, Tony Luck wrote:
> On Mon, Jul 18, 2011 at 1:30 PM, Matthew Garrett <mjg@redhat.com> wrote:.
> > +
> > +               Pstore only supports one backend at a time. If multiple
> > +               backends are available, the preferred backend may be
> > +               set by passing the pstore.backend= argument to the kernel
> > +               or writing to /sys/module/pstore/parameters/backend .
> > \ No newline at end of file
> 
> Maybe we should have a newline :-)

True...

> We don't allow backends to be unregistered (currently) - Do you think it would
> be helpful to mention in this text that you cannot change your mind and
> switch to a different back end once you have registered one? Writing
> to /sys/module/... sounds a lot more flexible than what reality will allow.

Mm. Yes, the lack of unregistration does make that less helpful. Perhaps 
best to make that unwritable.

> 
> > +       if (backend && strcmp(backend, psi->name)) {
> > +               spin_unlock(&pstore_lock);
> > +               return -EBUSY;
> > +       }
> 
> EBUSY doesn't feel like the right error here (and we are using that
> to indicate that some other backend is already registered).  Not
> sure what is the right one though. ENOENT? EINVAL?

EINVAL, I guess?

-- 
Matthew Garrett | mjg59@srcf.ucam.org