This brings explicit support in for the following versions of Ubuntu, which required refreshes of various ldiskfs kernel patches along the way:
    - 20.04 at 5.4.0-1091
    - 20.04 at 5.4.0-1095
    - 20.04 at 5.15.0-1034
    - 20.04 at 5.15.0-1046
    - 20.04 at 5.15.0-1056
    - 20.04 at 5.15.0-1058

Patch version between the 5.4 and 5.15 patch versions shown function as well, as does 5.15.0 up to the most recent patch available today.  Most testing was performed on 20.04.6 LTS, though some of the 5.4 testing was on 18.04 as well as 20.04 versions.

Patch to be sent shortly.