[Samba] Samba and BTRFS server-side copy

[Jeremy Allison]

On Fri, Oct 28, 2016 at 01:42:35AM +0200, Saint Germain via samba wrote:
> On Thu, 27 Oct 2016 16:27:05 -0700, Jeremy Allison <jra at samba.org>
> > if you see any of these then it happened.
> 
> Ok I understand how to check that it happened, but how can I make sure
> that it doesn't happen ?
> How can I ensure that clone range request sizes are integer divisible
> by 4096 on my server ?
> Should I change something on the BTRFS filesystem, or shift my
> partition or something ?

Nope. It's not a critical error. In smbclient, scopy
requests a copy of the entire filesize. The libsmbclient
layer splits this into copychunk requests of default
size 1mb - which is certainly integer divisible by
4096.

The only time you'll get the server copy is if the
last chunk isn't divisible by 4096. It's not a problem.