[dm-devel] [PATCH 06/12] multipathd: fix device creation issues

[Martin Wilck]

On Tue, 2018-01-30 at 12:34 -0600, Benjamin Marzinski wrote:
> On Tue, Jan 30, 2018 at 05:51:03PM +0100, Martin Wilck wrote:
> > 
> > It just occured to me while reviewing this patch once more that
> > this
> > might cause problems if the path WWID changes, as recently
> > discussed.Perhaps you should at least skip paths with the
> > "wwid_changed" attribute?
> 
> I thought that we agreed that updating pp->udev was a bad idea if the
> wwid changed.  I'm still not sure that we need to update the udev
> device
> at all.  For things that might reasonably change, we should grab them
> from sysfs or from the current uevent (without necessarily updating
> the
> one attached to the path). For things that aren't supposed to change,
> we
> can get them through libudev, and then they'll be cached for the
> future.
> 
> But at any rate, as long as we don't update pp->udev when the new
> udev
> device has a different wwid, this shouldn't be a problem. right?

Allright, the only thing that matters here is pp->hwe. So yes, we may
be ok. I have a rather bad feeling about these "zombie" paths being
carried around in multipathd, and parts of the code relying on that
being the case, but I guess I can't offer a better solution.

Thanks,
Martin

-- 
Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)