/sbin/btrfs-calc-size
/sbin/btrfsck
/sbin/btrfs-convert
/sbin/btrfs
/sbin/btrfs-debug-tree
/sbin/btrfs-find-root
/sbin/btrfs-image
/sbin/btrfs-map-logical
/sbin/btrfs-select-super
/sbin/btrfs-show-super
/sbin/btrfstune
/sbin/btrfs-zero-log
/sbin/fsck.btrfs
/sbin/mkfs.btrfs
You may install this package on Debian with
apt-get
install btrfs-tools