btrfs: cloning of compressed inline extent after truncation

btrfs: cloning of compressed inline extent after truncation

Test that truncating a file that consists of a compressed and inlined extent
to a smaller size and then cloning it into another file is not possible and
does not result in leaking stale data (data past the truncation offset) nor
losing data in the clone operation's destination file.

This btrfs issue is fixed by the linux kernel patch titled:

  "Btrfs: fix truncation of compressed and inlined extents"

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>