[dm-devel] [PATCH 7/8] dm: delay registering the gendisk

[Alasdair G Kergon]

On Tue, Aug 10, 2021 at 12:31:43AM +0100, Alasdair G Kergon wrote:
> When loading tables, our tools also always refer to devices using
> the 'major:minor' format, which isn't affected, rather than using
                            ^^^^^^^^^^^^^^^^^^^^
Wrong - that is also affected.

So there is a new general constraint that a table must be loaded into a
device before another device's table can reference that device.  (The
stacked device handling in lvm2 as supported by libdevmapper should
always be doing this.)

(The original implementation had to be a bit loose to accommodate
multipath device paths that were essentially placeholders at the point
they got set up.)

Alasdair