Which three statements are true about Btrfs copy —reflink?

A.
Itworks only on the samebtrfsfile system.

B.
tt works only on the same subvolumes.

C.
it creates a new link pointing to an existing inode.

D.
it creates a new inode that shares the same disk blocks as the original.

E.
it creates a clone file and disk blocks are duplicated.

Explanation:
Reference:https://blogs.oracle.com/OTNGarage/entry/save_disk_space_on_linux