This only falls back if the plain version of balance start is used.
Any args make us report the ioctl isn't supported.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add balance command group under both 'btrfs' and 'btrfs filesystem'.
Preserve the old 'btrfs filesystem balance <path>' behaviour.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>