Re: GRUB bug with Btrfs multiple devices

From: Andrei Borzenkov <arvidjaar@gmail.com>
To: Chris Murphy <lists@colorremedies.com>
Cc: Goffredo Baroncelli <kreijack@inwind.it>,
	Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: GRUB bug with Btrfs multiple devices
Date: Sat, 30 Nov 2019 10:31:04 +0300	[thread overview]
Message-ID: <6bc5b69e-188e-a7b2-e695-bd1bcb6a9ba3@gmail.com> (raw)
In-Reply-To: <CAJCQCtTuu=k3FsKYmon4zP2b7c9D3zYzJwGZ3pLzFXMoJTepYA@mail.gmail.com>

30.11.2019 00:11, Chris Murphy пишет:
> On Fri, Nov 29, 2019 at 1:50 PM Andrei Borzenkov <arvidjaar@gmail.com> wrote:
>>
>> 27.11.2019 02:53, Chris Murphy пишет:
>>>
>>> The storage is one CD-ROM drive and one SSD drive. That's it. So I
>>> don't know why there's hd2 and hd3, it seems like GRUB is confused
>>> about how many drives there are, but that pre-dates this problem.
>>>
>>
>> grub enumerates what EFI provides. What "lsefi" in grub says?
> 
> https://photos.app.goo.gl/pBxLJNdbzz6J9Vo56
> 

These are vendor media device paths handles that are children of (some) 
disk partitions. GRUB already tries to skip such handles:

       /* Ghosts proudly presented by Apple.  */
       if (GRUB_EFI_DEVICE_PATH_TYPE (dp) == GRUB_EFI_MEDIA_DEVICE_PATH_TYPE
           && GRUB_EFI_DEVICE_PATH_SUBTYPE (dp)
           == GRUB_EFI_VENDOR_MEDIA_DEVICE_PATH_SUBTYPE)
         {
           grub_efi_vendor_device_path_t *vendor = 
(grub_efi_vendor_device_path_t *) dp;
           const struct grub_efi_guid apple = GRUB_EFI_VENDOR_APPLE_GUID;

           if (vendor->header.length == sizeof (*vendor)
               && grub_memcmp (&vendor->vendor_guid, &apple,
                               sizeof (vendor->vendor_guid)) == 0
               && find_parent_device (devices, d))
             continue;
         }

but these have different GUID. Google search comes with something 
hinting on Apple still (like 
https://www.macos86.it/topic/1136-asus-x202e-hm76-vs-n56vb-hm76/page/2/?tab=comments#comment-31186). 
  Device paths look like

PciRoot(0x0)\Pci(0x1F,0x2)\Sata(0x0,0xFFFF,0x0)\HD(4,GPT,A640EF60-F7E9-4945-81A9-B04CCE53EE97,0x176F4800,0x482FC88)\VenMedia(BE74FCF7-0B7C-49F3-9147-01F4042E6842,4F20CFA89785973FAAF730597BFC41BA)

where vendor GUID is BE74FCF7-0B7C-49F3-9147-01F4042E6842

So we have hard disk, then partition as child and then this vendor media 
as child of partition.

This should certainly be reported to grub list. What system is it - is 
it Apple?