reflink support and Samba running over XFS

[Christoph Hellwig]

On Wed, Nov 09, 2022 at 10:47:41AM -0800, Jeremy Allison via samba-technical wrote:
> So it *looks* like the copy_file_range() syscall will internally
> call the equivalent of FICLONERANGE if the underlying file
> system supports it.

Yes.  The separate clone interface exists for the cases where
applications only want to do the fast metadata only operation and
not fall back toan actual copy.  I'll leave it to people with more
SMB experience if and how that matters to the protocol.  For NFS
CLONE and COPY primitives exist on the wire with a similar distinction.