Re: [PATCH v5 2/4] iommufd: Add iommufd_access_replace() API

[Nicolin Chen]

On Fri, Mar 24, 2023 at 03:02:46AM +0000, Tian, Kevin wrote:
> External email: Use caution opening links or attachments
> 
> 
> > From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> > Sent: Thursday, March 23, 2023 4:33 PM
> >
> > +int iommufd_access_replace(struct iommufd_access *access, u32 ioas_id)
> > +{
> > +     struct iommufd_ioas *new_ioas;
> > +
> > +     mutex_lock(&access->ioas_lock);
> > +     if (!access->ioas) {
> >               mutex_unlock(&access->ioas_lock);
> > -             iommufd_put_object(obj);
> > -             return rc;
> > +             return -ENOENT;
> > +     }
> > +     if (access->ioas->obj.id == ioas_id) {
> > +             mutex_unlock(&access->ioas_lock);
> > +             return 0;
> >       }
> > -     iommufd_ref_to_users(obj);
> >
> > +     new_ioas = iommufd_access_change_pt(access, ioas_id);
> > +     if (IS_ERR(new_ioas)) {
> > +             mutex_unlock(&access->ioas_lock);
> > +             return PTR_ERR(new_ioas);
> > +     }
> > +     __iommufd_access_detach(access);
> >       access->ioas = new_ioas;
> >       access->ioas_unpin = new_ioas;
> 
> Above three lines can be moved into iommufd_access_change_pt():
> 
>         If (access->ioas)
>                 __iommufd_access_detach(access);
>         access->ioas = new_ioas;
>         access->ioas_unpin = new_ioas;
> 
> Then both attach/replace can end by calling the common function.

OK. Will do that in v6.

Thanks
Nicolin