Is this also the case for bcachefs? If that is the case, then the situation is even simpler - If filesystem can singal to vfs/ovl that directory is empty (i.e. S_EMPTYDIR) then overlayfs can ignore this dir altogether when composing the merged directory. But again, I don't think there is a good reason to treat this case of changing the underlying layer specially. Please explain if I missed anything. Thanks, Amir.
