Re: [dm-devel] [PATCH v2 0/4] Diskseq support in device-mapper

From: Martin Wilck
Date: Mon Jan 15 2024 - 12:56:38 EST


On Sat, 2023-06-24 at 19:09 -0400, Demi Marie Obenour wrote:
> This work aims to allow userspace to create and destroy device-mapper
> devices in a race-free way.

The discussion about this feature seems to have stalled ... will there
be a v3 of this series any time soon?

Also, I am wondering what should happen if a device-mapper table is
changed in a SUSPEND/LOAD/RESUME cycle. Such operations can change the
content of the device, thus I assume that the diskseq should also
change. But AFAICS this wasn't part of your patch set.

In general, whether the content changes in a reload operation depends
on the target. The multipath target, for example, reloads frequently
without changing the content of the dm device. An ever-changing diskseq
wouldn't make a lot of sense for dm-multipath. But I doubt we want to
start making distinctions on this level, so I guess that diskseq and
multipath just won't go well together.

Regards,
Martin