On Thu, Jul 15, 2021 at 01:23:36PM -0700, Luis Chamberlain wrote:

The GENHD_FL_UP is used internally so we can know when we can add and
remove partitions, so just clarify that. Right now it has this 1980's
description comparing it to network drivers "ifconfig up" idea, and
that can easily lead to invalid uses.

GENHD_FL_UP actually is pretty horrible - it uses a value used for
something that should be mostly read only at device runtime for
state an does so badly.  I actually have a patch to kill it, as we can
just check if the inode for the whole device blockdev is hashed instead.