> Excellent idea - you've just described fallthru dentries. :)
Yes.... after writing that I went back through the original article, noticed 'fallthru' this time, and felt a bit sheepish.
I don't quite see either how you would implement fallthru using whiteout though, or why you would still want whiteout if you were using copy-up + fallthru..
It is a pity that a block-based COW solution is so inefficent - it is such a simple solution that would address many of the use-cases (not the NFS-as-underlying-filesystem case of course).