Re: [PATCH] ovl: skip stale entries in merge dir cache iteration

[Amir Goldstein <amir73il@gmail.com>]

On Mon, Jul 19, 2021 at 6:24 PM Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> On Fri, 4 Jun 2021 at 12:43, Amir Goldstein <amir73il@gmail.com> wrote:
> >
> > On Mon, Apr 26, 2021 at 6:20 PM Amir Goldstein <amir73il@gmail.com> wrote:
> > >
> > > On the first getdents call, ovl_iterate() populates the readdir cache
> > > with a list of entries, but for upper entries with origin lower inode,
> > > p->ino remains zero.
> > >
> > > Following getdents calls traverse the readdir cache list and call
> > > ovl_cache_update_ino() for entries with zero p->ino to lookup the entry
> > > in the overlay and return d_ino that is consistent with st_ino.
> > >
> > > If the upper file was unlinked between the first getdents call and the
> > > getdents call that lists the file entry, ovl_cache_update_ino() will not
> > > find the entry and fall back to setting d_ino to the upper real st_ino,
> > > which is inconsistent with how this object was presented to users.
> > >
> > > Instead of listing a stale entry with inconsistent d_ino, simply skip
> > > the stale entry, which is better for users.
> > >
> >
> > Miklos,
> >
> > I forgot to follow up on this patch.
> > Upstream xfstest overlay/077 is failing without this patch.
>
> Can't reproduce (on ext4/xfs and "-oxino=on").
>
> Is there some trick?

Not sure. overlay/077 fails for me on v5.14.0-rc2 on ext4/xfs.

     QA output created by 077
    +entry m100 has inconsistent d_ino (234 != 232)
    +entry f100 has inconsistent d_ino (335 != 16777542)
     Silence is golden

Maybe you need to build src/t_dir_offset2?

Thanks,
Amir.