Re: [PATCH 2/3] ovl: Do not check for redirect if this is last layer

[Vivek Goyal <vgoyal@redhat.com>]

On Fri, Mar 09, 2018 at 12:27:21AM +0200, Amir Goldstein wrote:
> On Fri, Mar 9, 2018 at 12:18 AM, Vivek Goyal <vgoyal@redhat.com> wrote:
> > If we are looking in last layer, then there should not be any need to
> > process redirect. redirect information is used only for lookup in next
> > lower layer and there is no more lower layer to look into. So no need
> > to process redirects.
> >
> > IOW, ignore redirects on lowest layer.
> >
> > Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> 
> Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> 
> > ---
> >  fs/overlayfs/namei.c | 15 +++++++++------
> >  1 file changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
> > index 2e173cfbda0e..32d1d96f80b6 100644
> > --- a/fs/overlayfs/namei.c
> > +++ b/fs/overlayfs/namei.c
> > @@ -248,13 +248,16 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
> >                 goto out;
> >         }
> >         d->is_dir = true;
> > -       if (!d->last && ovl_is_opaquedir(this)) {
> > -               d->stop = d->opaque = true;
> > -               goto out;
> 
> I preferred to go with if (d->last) goto out; I like to avoid nesting
> when possible.
> but choose whichever you like.

I liked your version better as well. :-). Will do if (d->last) goto out;

Vivek

> 
> > +       if (!d->last) {
> > +               if (ovl_is_opaquedir(this)) {
> > +                       d->stop = d->opaque = true;
> > +                       goto out;
> > +               }
> > +
> > +               err = ovl_check_redirect(this, d, prelen, post);
> > +               if (err)
> > +                       goto out_err;
> >         }
> > -       err = ovl_check_redirect(this, d, prelen, post);
> > -       if (err)
> > -               goto out_err;
> >  out:
> >         *ret = this;
> >         return 0;
> > --
> > 2.13.6
> >