Should layernode Lookups for "diff1".. "diffN" be addressed in store/fs.go?

[GerrySeidman]

I was trying to understand why layernode lookups are occurring for the name = "diff1" in store/fs.go:

• func (n *layernode) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*fusefs.Inode, syscall.Errno)

Looking at the containers/storage repo, I see that in /drivers/overlay/overlay.go there is looping through "diff<diffN>" for the path filepath.Join(dir, nameWithSuffix("diff", diffN)) which were introduced along with these commits:

• Implement UpdateLayerIDMap for overlay
• Tighten permissions on created directory

It appears that that the use of"diff<diffN>" was added to better support Additional Image Stores, however I am having difficulty figuring out exactly what this is doing. I think it has something to do with UID/GID mappings.

Should stargz-snapshotter be doing anything with these?