Re: [PATCH v2 12/17] xen/hypfs: add new enter() and exit() per node callbacks

[Jürgen Groß <jgross@xxxxxxxx>]

On 04.12.20 09:30, Jan Beulich wrote:
> On 01.12.2020 09:21, Juergen Gross wrote:
> > @@ -100,11 +112,58 @@ static void hypfs_unlock(void)
> >       }
> >   }
> >   
> > +const struct hypfs_entry *hypfs_node_enter(const struct hypfs_entry *entry)
> > +{
> > +    return entry;
> > +}
> > +
> > +void hypfs_node_exit(const struct hypfs_entry *entry)
> > +{
> > +}
> > +
> > +static int node_enter(const struct hypfs_entry *entry)
> > +{
> > +    const struct hypfs_entry **last = &this_cpu(hypfs_last_node_entered);
> > +
> > +    entry = entry->funcs->enter(entry);
> > +    if ( IS_ERR(entry) )
> > +        return PTR_ERR(entry);
> > +
> > +    ASSERT(!*last || *last == entry->parent);
> > +
> > +    *last = entry;
> In such a callback case I wonder whether you wouldn't want to also
> guard against NULL coming back, perhaps simply by mistake, but of
> course once handling it here such could even become permissible
> behavior.
I think you are right. I should add an ASSERT(entry);


Juergen

Attachment: OpenPGP_0xB0DE9DD628BF132F.asc
Description: application/pgp-keys

Attachment: OpenPGP_signature
Description: OpenPGP digital signature