Re: [PATCH v12 09/17] ovl: Do not mark a non dir as _OVL_PATH_MERGE in ovl_path_type()

[Vivek Goyal <vgoyal@redhat.com>]

On Wed, Mar 07, 2018 at 09:07:22AM +0200, Amir Goldstein wrote:
> On Tue, Mar 6, 2018 at 10:54 PM, Vivek Goyal <vgoyal@redhat.com> wrote:
> > With the addition of an origin chain for regular files, it is possible
> > that we don't have an upperdentry and oe->numlower > 1 for non-dir. So
> > mark a path __OVL_TYPE_MERGE only if it is a directory.
> >
> 
> Okay, but what's wrong with marking a non-dir as TYPE MERGE?
> It is, after all, a sort of merged entry.

Conceptually, I can't think of anything wrong. Just that currently we use
MERGE in the context of directory and we don't need it in the context of
non-dir. So this is just trying to be safe to make sure not to break any
existing code. 

I guess we could mark metacopy regular files as MERGE as well, if need be.
But that could be part of a separate patch series where we could run
various tests and make sure nothing is broken.

Vivek

> 
> > Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
> > ---
> >  fs/overlayfs/util.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
> > index 7929cc872df6..19b936b0a551 100644
> > --- a/fs/overlayfs/util.c
> > +++ b/fs/overlayfs/util.c
> > @@ -122,7 +122,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry)
> >                                 type |= __OVL_PATH_MERGE;
> >                 }
> >         } else {
> > -               if (oe->numlower > 1)
> > +               if (oe->numlower > 1 && d_is_dir(dentry))
> >                         type |= __OVL_PATH_MERGE;
> >         }
> >         return type;
> > --
> > 2.13.6
> >