On Mon, Jun 12, 2023 at 09:37:51AM +0300, Amir Goldstein wrote:
> On Mon, Jun 12, 2023 at 7:45 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> >
> > On Sun, Jun 11, 2023 at 10:47:05PM +0300, Amir Goldstein wrote:
> > > Overlayfs and cachefiles use open_with_fake_path() to allocate internal
> > > files, where overlayfs also puts a "fake" path in f_path - a path which
> > > is not on the same fs as f_inode.
> >
> > But cachefs doesn't, so this needs a better explanation / documentation.
> >
> > > Allocate a container struct file_fake for those internal files, that
> > > is used to hold the fake path along with an optional real path.
> >
> > The idea looks sensible, but fake a is a really weird term here.
> > I know open_with_fake_path also uses it, but we really need to
> > come up with a better name, and also good documentation of the
> > concept here.
> >
> > > +/* Returns the real_path field that could be empty */
> > > +struct path *__f_real_path(struct file *f)
> > > +{
> > > + struct file_fake *ff = file_fake(f);
> > > +
> > > + if (f->f_mode & FMODE_FAKE_PATH)
> > > + return &ff->real_path;
> > > + else
> > > + return &f->f_path;
> > > +}
> >
> > two of the three callers always have FMODE_FAKE_PATH set, so please
> > just drop this helper and open code it in the three callers.
> >
>
> I wanted to keep the container opaque
This is preferable to me tbh to not leak this detail into callsites.
