Bug#717720: grub-pc: grub-install/update-grub and btrfs.mod disagree about root path

Tobias Gruetzmacher tobias-debian at 23.gs
Wed Jul 24 09:15:00 UTC 2013


Package: grub-pc
Version: 2.00-15
Severity: normal

Dear Maintainer,

testing btrfs I came across a situation where grubn is unable to boot the
system with the configuration it generated. My btrfs is set up like this:

$ sudo btrfs subvolume list /
ID 257 gen 11785 top level 5 path root
ID 258 gen 11785 top level 5 path home

$ mount
[...]
/dev/sda1 on / type btrfs (rw,relatime,compress=lzo,ssd,space_cache)
/dev/sda1 on /home type btrfs (rw,relatime,compress=lzo,ssd,space_cache)

The home directory is mounted with subvol=/home, which you can't see in the
mount output.

As you can see, the btrfs has 2 subvolumes. subvolume /root was set as default.
I think there lies the problem. btrfs.mod considers the btrfs default and
searches everything from the /root subvolume, but grub's userspace tools
generate all paths from the root of the btrfs filesystem.

I don't know which side is in error, but I would lean more in the direction of
btrfs.mod, so you can access any subvolume from grub.

Best regards, Tobias

PS: grub currently just boots into rescue mode, to get to normal mode, I just
fix the prefix variable (set prefix=(hd0,msdos1)/boot/grub/i386-pc) and then
load (insmod normal) and start (normal) normal mode. After that I still have to
fix the kernel command line...

PPS: I think it worked in 1.99, maybe?

-- Package-specific info:

*********************** BEGIN /proc/mounts
/dev/sda1 / btrfs rw,relatime,compress=lzo,ssd,space_cache 0 0
/dev/sda1 /home btrfs rw,relatime,compress=lzo,ssd,space_cache 0 0
*********************** END /proc/mounts

*********************** BEGIN /boot/grub/grub.cfg
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  load_env
fi
set default="0"

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_msdos
insmod btrfs
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  93d8a4bf-d419-4398-8275-cf36e31db859
else
  search --no-floppy --fs-uuid --set=root 93d8a4bf-d419-4398-8275-cf36e31db859
fi
    font="/root/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=1024x768
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=de_DE
  insmod gettext
fi
terminal_output gfxterm
set timeout=5
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
insmod part_msdos
insmod btrfs
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  93d8a4bf-d419-4398-8275-cf36e31db859
else
  search --no-floppy --fs-uuid --set=root 93d8a4bf-d419-4398-8275-cf36e31db859
fi
insmod png
if background_image /root/usr/share/images/desktop-base/joy-grub.png; then
  set color_normal=white/black
  set color_highlight=black/white
else
  set menu_color_normal=cyan/blue
  set menu_color_highlight=white/blue
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Debian GNU/Linux' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-93d8a4bf-d419-4398-8275-cf36e31db859' {
	load_video
	set gfxpayload=keep
	insmod gzio
	insmod part_msdos
	insmod btrfs
	set root='hd0,msdos1'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  93d8a4bf-d419-4398-8275-cf36e31db859
	else
	  search --no-floppy --fs-uuid --set=root 93d8a4bf-d419-4398-8275-cf36e31db859
	fi
	echo	'Loading Linux 3.10-1-amd64 ...'
	linux	/root/boot/vmlinuz-3.10-1-amd64 root=UUID=93d8a4bf-d419-4398-8275-cf36e31db859 ro rootflags=subvol=root  init=/bin/systemd quiet fastboot
	echo	'Loading initial ramdisk ...'
	initrd	/root/boot/initrd.img-3.10-1-amd64
}
submenu 'Advanced options for Debian GNU/Linux' $menuentry_id_option 'gnulinux-advanced-93d8a4bf-d419-4398-8275-cf36e31db859' {
	menuentry 'Debian GNU/Linux, with Linux 3.10-1-amd64' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.10-1-amd64-advanced-93d8a4bf-d419-4398-8275-cf36e31db859' {
		load_video
		set gfxpayload=keep
		insmod gzio
		insmod part_msdos
		insmod btrfs
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  93d8a4bf-d419-4398-8275-cf36e31db859
		else
		  search --no-floppy --fs-uuid --set=root 93d8a4bf-d419-4398-8275-cf36e31db859
		fi
		echo	'Loading Linux 3.10-1-amd64 ...'
		linux	/root/boot/vmlinuz-3.10-1-amd64 root=UUID=93d8a4bf-d419-4398-8275-cf36e31db859 ro rootflags=subvol=root  init=/bin/systemd quiet fastboot
		echo	'Loading initial ramdisk ...'
		initrd	/root/boot/initrd.img-3.10-1-amd64
	}
	menuentry 'Debian GNU/Linux, with Linux 3.9-1-amd64' --class debian --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.9-1-amd64-advanced-93d8a4bf-d419-4398-8275-cf36e31db859' {
		load_video
		set gfxpayload=keep
		insmod gzio
		insmod part_msdos
		insmod btrfs
		set root='hd0,msdos1'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  93d8a4bf-d419-4398-8275-cf36e31db859
		else
		  search --no-floppy --fs-uuid --set=root 93d8a4bf-d419-4398-8275-cf36e31db859
		fi
		echo	'Loading Linux 3.9-1-amd64 ...'
		linux	/root/boot/vmlinuz-3.9-1-amd64 root=UUID=93d8a4bf-d419-4398-8275-cf36e31db859 ro rootflags=subvol=root  init=/bin/systemd quiet fastboot
		echo	'Loading initial ramdisk ...'
		initrd	/root/boot/initrd.img-3.9-1-amd64
	}
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
*********************** END /boot/grub/grub.cfg

*********************** BEGIN /proc/mdstat
cat: /proc/mdstat: No such file or directory
*********************** END /proc/mdstat

*********************** BEGIN LVM
*********************** END LVM

*********************** BEGIN /dev/disk/by-id
total 0
lrwxrwxrwx 1 root root  9 Jul 24 10:13 ata-VBOX_CD-ROM_VB1-1a2b3c4d -> ../../sr0
lrwxrwxrwx 1 root root  9 Jul 24 10:13 ata-VBOX_HARDDISK_VB88d1fd94-dcccde4a -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 24 10:13 ata-VBOX_HARDDISK_VB88d1fd94-dcccde4a-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 24 10:13 ata-VBOX_HARDDISK_VB88d1fd94-dcccde4a-part2 -> ../../sda2
lrwxrwxrwx 1 root root  9 Jul 24 10:13 scsi-SATA_VBOX_HARDDISK_VB88d1fd94-dcccde4a -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 24 10:13 scsi-SATA_VBOX_HARDDISK_VB88d1fd94-dcccde4a-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jul 24 10:13 scsi-SATA_VBOX_HARDDISK_VB88d1fd94-dcccde4a-part2 -> ../../sda2
*********************** END /dev/disk/by-id

*********************** BEGIN /dev/disk/by-uuid
total 0
lrwxrwxrwx 1 root root 10 Jul 24 10:13 547886e6-d0da-40ab-98ab-252621672b2d -> ../../sda2
lrwxrwxrwx 1 root root 10 Jul 24 10:13 93d8a4bf-d419-4398-8275-cf36e31db859 -> ../../sda1
*********************** END /dev/disk/by-uuid

-- System Information:
Debian Release: jessie/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (101, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.10-1-amd64 (SMP w/1 CPU core)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages grub-pc depends on:
ii  debconf [debconf-2.0]  1.5.50
ii  grub-common            2.00-15
ii  grub-pc-bin            2.00-15
ii  grub2-common           2.00-15
ii  ucf                    3.0027+nmu1

grub-pc recommends no packages.

grub-pc suggests no packages.

-- debconf information:
  grub-pc/kopt_extracted: false
  grub2/kfreebsd_cmdline:
  grub2/device_map_regenerated:
* grub-pc/install_devices: /dev/disk/by-id/ata-VBOX_HARDDISK_VB88d1fd94-dcccde4a
  grub-pc/postrm_purge_boot_grub: false
  grub-pc/install_devices_failed_upgrade: true
  grub-pc/disk_description:
* grub2/linux_cmdline:
  grub-pc/install_devices_empty: false
  grub2/kfreebsd_cmdline_default: quiet
  grub-pc/partition_description:
  grub-pc/install_devices_failed: false
* grub-pc/install_devices_disks_changed: /dev/disk/by-id/ata-VBOX_HARDDISK_VB708f1f3e-12482856
* grub2/linux_cmdline_default: init=/bin/systemd quiet
  grub-pc/chainload_from_menu.lst: true
  grub-pc/mixed_legacy_and_grub2: true



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