Cleans up loop devices if part of the test or mount process fails.
Also increases btrfs default file size to 650MB to accommodate
minimum btrfs size on ppc64le and s390x
Signed-off-by: Christopher Jones <tophj@linux.vnet.ibm.com>
Implements btrfs usage using a double walking diff and
counting the result. Walking gives the most accurate
count and includes inode usage.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>