Minor Description
There are many "command groups" like "lctl lfsck_start", "... lfsck_stop", "... lfsck_query" that would be better handled as subcommands like "lctl lfsck start", "lctl lfsck stop", etc. in the way that "lfs mirror create" and "lfs pcc attach" are implemented.
For lctl these include barrier_*, snapshot_*, lcfg_*, llog_*, nodemap_*, net_drop_*, net_delay_*, changelog_*, and for lfs it is only hsm_*.
Probably each one could be a separate patch. The old commands should be kept for compatibility, but the usage messages and man pages should all reference the new format.
The man page should be renamed, but there should also should be manpage .so link added for the old format of the command (with a "-" instead of a "_" in the name).