Introduce a new test image, which has an extent item with no inlined
extent data ref, but all keyed extent data ref.
Only in this case we can trigger fase data extent backref lost bug in
lowmem mode.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo