are reflink copies atomic on Btrfs?

[Chris Murphy <lists@xxxxxxxxxxxxxxxxx>]

I was referred to this on the XFS list
https://www.spinics.net/lists/linux-xfs/msg15969.html

That suggests that, at least in theory, they are atomic on XFS. But
I'm not sure what that numbered list looks like on Btrfs either, and
whether there are expected differences.

Thanks,

-- 
Chris Murphy