#!/bin/bash
BVOL1=$1
BVOL2=$2

uname -a
btrfs --version

cd "$BVOL1"
btrfs sub create C
dd if=/dev/urandom of=C/test count=100
cp --reflink=always -vp C/test{,.ref}
btrfs property set C ro true
btrfs send -v C | btrfs receive "$BVOL2"
btrfs fi du C/* "$BVOL2"/C/*