Chunker storing unmodified files

NEWB here, sorry
Is it possible for go-ipfs to cache the unmodified files in .ipfs/blocks/… ?
I guess ipfs add --chunker option influence the behavior but I cannot find the right argument.
The idea behind it is to hardlink ipfs cache to the original files stored on FS (using freedup or alike).

Have you tried ipfs add --no-copy ?
It might be what you are looking for. It will still be chunked, but IPFS will only store the metadata about the file. the actual file should stay where it is, and IPFS won’t be able to access it if it’s deleted from FS.

Take a look at the experimental filestore feature:

Note: if you change one of the original files, you’ll corrupt your IPFS repo.

Thanks, this quite answers my question.