grub-probe can't find device (regression) Bug #33133

grub-probe can't find device (regression) Bug #33133

[Ian Dall]

I have reported bug #33133 in savannah.

The issue is that "grub-probe -v --target=device /tmp/root/boot" fails
in current trunk. The issue appears to have been introduced in revision
3214 into
grub/grub-core/kern/emu/getroot.c:grub_find_root_device_from_mountinfo().

/tmp for me is a tmpfs. /tmp/root has mounted on it a USB pen
(/dev/sdd1).

Steppign through with gdb, it seems that the list of entries gets
created properly, but around line 209, there is something curious:

      if (entries[i].major != 0)
	continue; /* not a virtual device */

which I can't understand. Its effect is to always skip over mount points
for real devices. I'm not really sure I completely understand what this
virtual device work around is. But may this whole test is just bogus.
Why not the "lowest" mount enclosing the path?

Regards,
Ian
 

-- 
Ian Dall <ian@beware.dropbear.id.au>

Re: grub-probe can't find device (regression) Bug #33133

[Vladimir 'φ-coder/phcoder' Serbinenko]

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> Steppign through with gdb, it seems that the list of entries gets
> created properly, but around line 209, there is something curious:
>
>       if (entries[i].major != 0)
> 	continue; /* not a virtual device */
@cjwatson: it's a mismerge. Could you fix it?

-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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Re: grub-probe can't find device (regression) Bug #33133

[Colin Watson]

On Thu, Apr 21, 2011 at 09:29:46AM +0200, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
> Ian Dall wrote:
> > Steppign through with gdb, it seems that the list of entries gets
> > created properly, but around line 209, there is something curious:
> >
> >       if (entries[i].major != 0)
> > 	continue; /* not a virtual device */
> 
> @cjwatson: it's a mismerge. Could you fix it?

It is indeed.  Sorry about that.  I had the two relevant patches in the
opposite order in my quilt series from the order in which they were
applied to trunk, and a certain amount of confusion resulted from
resolving this.

I've removed this bogus test now.

2011-04-21  Colin Watson  <cjwatson@ubuntu.com>

	* grub-core/kern/emu/getroot.c
	(grub_find_root_device_from_mountinfo): Remove non-virtual-device
	test that was incorrectly reintroduced in r3214.
	Reported by: Ian Dall.  Fixes Savannah bug #33133.

Thanks,

-- 
Colin Watson                                       [cjwatson@ubuntu.com]