Maybe I'm doing it entirely wrong, but I can't seem to get 'btrfs scrub resume' to work properly. During a running scrub the resume information (like data_bytes_scrubbed:1081454592) gets written to a file in /var/lib/btrfs, but as soon as the scrub is cancelled all relevant fields are zeroed. 'btrfs scrub resume' then seems to re-start from the very beginning. This is on linux-5.5-rc5 and btrfs-progs 5.4, but I've been seeing this for a while now. Is this intended/expected behavior? Am I using the btrfs-progs wrong? How can I interrupt and resume a scrub?
