ceph: use copy-from2 op in copy_file_range

ceph: use copy-from2 op in copy_file_range

Instead of using the copy-from operation, switch copy_file_range to the
new copy-from2 operation, which allows to send the truncate_seq and
truncate_size parameters.

If an OSD does not support the copy-from2 operation it will return
-EOPNOTSUPP.  In that case, the kernel client will stop trying to do
remote object copies for this fs client and will always use the generic
VFS copy_file_range.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>