[Libguestfs] [PATCH INCOMPLETE] daemon: Reimplement LVM filters using lvmdevices command

[David Teigland]

> > The modern way of this with new lvm is simply:
> > 
> >    --devices /dev/sdb,/dev/sde

> Unfortunately this doesn't work if /dev/sdb is partitioned.  You have
> to list all the partitions explicitly.
> 
> This is a change (regression, really) over the existing behaviour
> where it was possible to specify a regexp such as a|^/dev/sdb$|,
> a|^/dev/sdb[0-9]| to mean either /dev/sdb or any current or future
> partition of /dev/sdb.
> 
> This is what we baked into the libguestfs API and I'm trying to make
> work again.

You can certainly continue using the lvm filter since it's unlikely to
ever go away (set use_devicesfile=0 in the lvm config).

The devices file is clearly at odds with this usage, since the central
premise is to prescribe exactly which devices lvm can use.  But, using an
option like --devices to specify a pattern of allowed devices would
probably make sense.

Dave