Re: [PATCH] Fix when installing on pationless but partionable medium

[Robert Millan <rmh@aybabtu.com>]

On Sat, Jul 18, 2009 at 09:00:36PM +0200, Vladimir 'phcoder' Serbinenko wrote:
> On Sat, Jul 18, 2009 at 8:42 PM, Robert Millan<rmh@aybabtu.com> wrote:
> > On Fri, Jul 17, 2009 at 06:41:59PM +0200, Vladimir 'phcoder' Serbinenko wrote:
> >> Sometimes a media that can be partioned isn't really partioned. E.g.
> >> usb sticks. This is a patch to handle this situation.
> >
> > But we had a check for this already, is it not working?
> >
> >  if (! dest_dev->disk->has_partitions)
> >    {
> >      grub_util_warn ("Attempting to install GRUB to a partitionless disk.  This is a BAD idea.");
> >      goto unable_to_embed;
> >    }
> has_partitions is set by driver and has_partitions is a misnomer and
> it should be really can_be_partitioned.

You're right.  I think it's fine if we rename it.

> As a matter of fact this is
> even more problematic since whether has_partition is set or no often
> depends whether author know about partitioned media of given kind. I
> think this field should be ditched altogether

I don't understand what you mean here.

> > I'm not sure there's much we can do about this.  Using heuristics sounds like
> > it will make the solution worse than the problem.  I don't care much about
> > Microsoft filesystems, but I'd hate to see GRUB fail on a completely sane
> > ext3 inside msdos label because it happened to look like FAT in raw disk at
> > the same time.
> The approach proposed by Collin avoids such problems since correct
> pc_partition_map is always detected as such.

I haven't looked at the source code, but what he said is we can determine if
an MBR is valid by checking the bootable flag, and this is not always so.

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."