Ondrej Kozina authored Aug 25, 2020 and Milan Broz committed Aug 27, 2020

In case LUKS2 backup segment creates gap in between last regular
segment and backup segment report invalid metadata imediately. We stop
on first error so there's no need to allocate large memory on heap
(we may ran with mlock(MCL_FUTURE) set).

Example:
- total segments count is 3
- regular segments have keys "0" and "1"
- first backup segment has key "42"