Might be easy to extende fdupes and jdupes to be able to do this without much effort. I haven't seen the api/syscall invokved but I use them with btrfs for a s

Might be easy to extende fdupes and jdupes to be able to do this without much effort. I haven't seen the api/syscall invokved but I use them with btrfs for a specific use where I have a lot of known duplicates.