Re: [PATCH v3] erofs: use Z_EROFS_LCLUSTER_TYPE_MAX to simplify switches

[Hongzhen Luo]

On 2025/2/10 10:59, Gao Xiang wrote:
> On 2025/2/7 17:14, Gao Xiang wrote:
> > On 2025/2/7 16:50, Hongzhen Luo wrote:
> > > There's no need to enumerate each type. No logic changes.
> > >
> > > Signed-off-by: Hongzhen Luo <hongzhen@xxxxxxxxxxxxxxxxx>
> > > ---> v3: Code cleanup, remove logically inequivalent changes.
> > > v2: 
> > > https://lore.kernel.org/all/20250207080829.2405528-1-hongzhen@xxxxxxxxxxxxxxxxx/
> > > v1: 
> > > https://lore.kernel.org/all/20250207064135.2249529-1-hongzhen@xxxxxxxxxxxxxxxxx/
> > > ---
> > >   fs/erofs/zmap.c | 60 
> > > +++++++++++++++++++------------------------------
> > >   1 file changed, 23 insertions(+), 37 deletions(-)
> > >
> > > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > > index 689437e99a5a..7dba1573498b 100644
> > > --- a/fs/erofs/zmap.c
> > > +++ b/fs/erofs/zmap.c
> > > @@ -265,23 +265,20 @@ static int z_erofs_extent_lookback(struct 
> > > z_erofs_maprecorder *m,
> > >           if (err)
> > >               return err;
> > > -        switch (m->type) {
> > > -        case Z_EROFS_LCLUSTER_TYPE_NONHEAD:
> > > +        if (m->type >= Z_EROFS_LCLUSTER_TYPE_MAX) {
> > > +            erofs_err(sb, "unknown type %u @ lcn %lu of nid %llu",
> > > +                  m->type, lcn, vi->nid);
> > > +            DBG_BUGON(1);
> > > +            return -EOPNOTSUPP;
> > > +        } else if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
> > >               lookback_distance = m->delta[0];
> > >               if (!lookback_distance)
> > >                   goto err_bogus;'
> >
> > Maybe just kill `goto err_bogus;` too, like:
> >                          if (!lookback_distance) {
> >                                  erofs_err(sb, "bogus lookback 
> > distance %u @ lcn %lu of nid %llu",
> >                                            lookback_distance, m->lcn, 
> > vi->nid);
> >                                  DBG_BUGON(1);
> >                                  return -EFSCORRUPTED;
> >                          }
> >
> > Otherwise it looks good to me.
>
> Sorry, I was wrong.  I was missing the part of the end of
> function, how about the following diff?
>
> diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> index 7dba1573498b..d278ebd60281 100644
> --- a/fs/erofs/zmap.c
> +++ b/fs/erofs/zmap.c
> @@ -273,7 +273,7 @@ static int z_erofs_extent_lookback(struct 
> z_erofs_maprecorder *m,
>                 } else if (m->type == Z_EROFS_LCLUSTER_TYPE_NONHEAD) {
>                         lookback_distance = m->delta[0];
>                         if (!lookback_distance)
> -                               goto err_bogus;
> +                               break;
>                         continue;
>                 } else {
>                         m->headtype = m->type;
> @@ -281,7 +281,6 @@ static int z_erofs_extent_lookback(struct 
> z_erofs_maprecorder *m,
>                         return 0;
>                 }
>         }
> -err_bogus:
>         erofs_err(sb, "bogus lookback distance %u @ lcn %lu of nid %llu",
>                   lookback_distance, m->lcn, vi->nid);
>         DBG_BUGON(1);
>
> Thanks,
> Gao Xiang

Sure, I will send an updated version later.

Thanks,
Hongzhen Luo