[tuellm...@kit.edu: Bug#866603: grub-common: enabling metadata_csum_seed feature on ext4 renders system unbootable]
Hi,
Could we possibly just ignore this feature for GRUB? For better or
worse we don't implement metadata checksumming, and we're only doing
read-only access, so I think it would be reasonably safe to ignore
metadata_csum_seed since we wouldn't do anything with it anyway.
Thanks,
--
Colin Watson [cjwat...@debian.org]
--- Begin Message ---
Package: grub-common
Version: 2.02-1
Severity: important
Dear Maintainer,
enabling metadata_csum_seed allows to change the UUID of a mounted ext4
filesystem, which
is useful for cloned virtual machines. Unfortunately, grub does not recognize
this feature.
If this is enabled on the root filesystem, the system is rendered unbootable.
root@stretch:~# grub-probe --target=fs --device /dev/sda1
ext2
root@stretch:~# tune2fs -O metadata_csum_seed /dev/sda1
tune2fs 1.43.4 (31-Jan-2017)
root@stretch:~# grub-probe --target=fs --device /dev/sda1
grub-probe: error: unknown filesystem.
root@stretch:~# file -Ls /dev/sda1
/dev/sda1: Linux rev 1.0 ext4 filesystem data,
UUID=e692d65c-6677-4123-8bef-5daa7edb1a52 (needs journal recovery) (extents)
(64bit) (large files) (huge files)
Thorsten
-- Package-specific info:
*** BEGIN /proc/mounts
/dev/sda1 / ext4 rw,relatime,errors=remount-ro,data=ordered 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 $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="0"
fi
if [ x"${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$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
}
if loadfont unicode ; then
set gfxmode=auto
load_video
insmod gfxterm
set locale_dir=$prefix/locale
set lang=en_US
insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
set timeout=30
else
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=menu
set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
set timeout=5
fi
fi
### END /etc/grub.d/00_header ###
### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=cyan/blue
set menu_color_highlight=white/blue
### END /etc/grub.d/05_debian_theme ###
### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
set gfxpayload="${1}"
}
set linux_gfx_mode=
export linux_gfx_mode
menuentry 'Debian GNU/Linux' --class debian --class gnu-linux --class gnu
--class os $menuentry_id_option 'gnulinux-simple-/dev/sda1' {
load_video
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
insmod part_msdos
echo'Loading Linux 4.9.0-3-amd64 ...'
linux /boot/vmlinuz-4.9.0-3-amd64 root=/dev/sda1 ro quiet
echo'Loading initial ramdisk ...'
initrd /boot/initrd.img-4.9.0-3-amd64
}
submenu 'Advanced options for Debian GNU/Linux' $menuentry_id_option
'gnulinux-advanced-/dev/sda1' {
menuentry 'Debian GNU/Linux, with Linux 4.9.0-3-amd64' --class debian
--class gnu-linux --class gnu --class os $menuentry_id_option
'gnulinux-4.9.0-3-amd64-advanced-/dev/sda1' {
load_video
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio;
fi
insmod part_msdos
echo'Loading Linux 4.9.0-3-amd64 ...'
linux /boot/vmlinuz-4.9.0-3-amd64 root=/dev/sda1 ro quiet
echo'Loading initial ramdisk ...'
initrd /boot/initrd.img-4.9.0-3-amd64
}
menuentry 'Debian GNU/Linux, with Linux 4.9.0-3-amd64 (recovery mode)'
--class debian --class gnu-linux --class gnu --class os $menuentry_id_option
'gnulinux-4.9.0-3-amd64-recovery-/dev/sda1' {
load_video
insmod gzio
if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio;
fi
insmod part_msdos
echo'Loading Linux 4.9.0-3-amd64 ...'
linux /boot/vmlinuz-4.9.0-3-amd64 root=/dev/sda1 ro single
echo'Loading initial ramdisk
Re: [tuellm...@kit.edu: Bug#866603: grub-common: enabling metadata_csum_seed feature on ext4 renders system unbootable]
пт, 30 июн. 2017 г., 14:38 Colin Watson :
> Hi,
>
> Could we possibly just ignore this feature for GRUB? For better or
> worse we don't implement metadata checksumming, and we're only doing
> read-only access, so I think it would be reasonably safe to ignore
> metadata_csum_seed since we wouldn't do anything with it anyway.
Is it incompat rather than ro_compat? If so, why?
>
> Thanks,
>
> --
> Colin Watson [cjwat...@debian.org]
>
>
>
> -- Forwarded message --
> From: "Thorsten Tüllmann"
> To: Debian Bug Tracking System
> Cc:
> Bcc:
> Date: Fri, 30 Jun 2017 14:00:27 +0200
> Subject: Bug#866603: grub-common: enabling metadata_csum_seed feature on
> ext4 renders system unbootable
> Package: grub-common
> Version: 2.02-1
> Severity: important
>
> Dear Maintainer,
>
> enabling metadata_csum_seed allows to change the UUID of a mounted ext4
> filesystem, which
> is useful for cloned virtual machines. Unfortunately, grub does not
> recognize this feature.
> If this is enabled on the root filesystem, the system is rendered
> unbootable.
>
> root@stretch:~# grub-probe --target=fs --device /dev/sda1
> ext2
> root@stretch:~# tune2fs -O metadata_csum_seed /dev/sda1
> tune2fs 1.43.4 (31-Jan-2017)
> root@stretch:~# grub-probe --target=fs --device /dev/sda1
> grub-probe: error: unknown filesystem.
> root@stretch:~# file -Ls /dev/sda1
> /dev/sda1: Linux rev 1.0 ext4 filesystem data,
> UUID=e692d65c-6677-4123-8bef-5daa7edb1a52 (needs journal recovery)
> (extents) (64bit) (large files) (huge files)
>
> Thorsten
>
>
> -- Package-specific info:
>
> *** BEGIN /proc/mounts
> /dev/sda1 / ext4 rw,relatime,errors=remount-ro,data=ordered 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 $prefix/grubenv ]; then
> set have_grubenv=true
> load_env
> fi
> if [ "${next_entry}" ] ; then
>set default="${next_entry}"
>set next_entry=
>save_env next_entry
>set boot_once=true
> else
>set default="0"
> fi
>
> if [ x"${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$feature_all_video_module = xy ]; then
> insmod all_video
> else
> insmod efi_gop
> insmod efi_uga
> insmod ieee1275_fb
> insmod vbe
> insmod vga
> insmod video_bochs
> insmod video_cirrus
> fi
> }
>
> if loadfont unicode ; then
> set gfxmode=auto
> load_video
> insmod gfxterm
> set locale_dir=$prefix/locale
> set lang=en_US
> insmod gettext
> fi
> terminal_output gfxterm
> if [ "${recordfail}" = 1 ] ; then
> set timeout=30
> else
> if [ x$feature_timeout_style = xy ] ; then
> set timeout_style=menu
> set timeout=5
> # Fallback normal timeout code in case the timeout_style feature is
> # unavailable.
> else
> set timeout=5
> fi
> fi
> ### END /etc/grub.d/00_header ###
>
> ### BEGIN /etc/grub.d/05_debian_theme ###
> set menu_color_normal=cyan/blue
> set menu_color_highlight=white/blue
> ### END /etc/grub.d/05_debian_theme ###
>
> ### BEGIN /etc/grub.d/10_linux ###
> function gfxmode {
> set gfxpayload="${1}"
> }
> set linux_gfx_mode=
> export linux_gfx_mode
> menuentry 'Debian GNU/Linux' --class debian --class gnu-linux --class gnu
> --class os $menuentry_id_option 'gnulinux-simple-/dev/sda1' {
> load_video
> insmod gzio
> if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
> insmod part_msdos
> echo'Loading Linux 4.9.0-3-amd64 ...'
> linux /boot/vmlinuz-4.9.0-3-amd64 root=/dev/sda1 ro quiet
> echo'Loading initial ramdisk ...'
> initrd /boot/initrd.img-4.9.0-3-amd64
> }
> submenu 'Advanced options for Debian GNU/Linux' $menuentry_id_option
> 'gnulinux-advanced-/dev/sda1' {
> menuentry 'Debian GNU/Linux, with Linux 4.9.0-3-amd64' --class
> debian --class gnu-linux --class gnu --class os $menuentry_id_option
> 'gnulinux-4.9.0-3-amd64-advanced-/dev/sda1' {
> load_video
> insmod gzio
> if [ x$grub_platform = xxen ]; then insmod xzio; insmod
> lzopio; fi
> insmod part_msdos
> echo'Loading Linux 4.9.0-3-amd64 ...'
> linux /boot/vmlinuz-4.9.0-3-amd64 root=/dev/sda1 ro
> quiet
> echo'Loading initial ra
Re: [tuellm...@kit.edu: Bug#866603: grub-common: enabling metadata_csum_seed feature on ext4 renders system unbootable]
On Fri, Jun 30, 2017 at 12:43:02PM +, Vladimir 'phcoder' Serbinenko wrote: > пт, 30 июн. 2017 г., 14:38 Colin Watson : > > Could we possibly just ignore this feature for GRUB? For better or > > worse we don't implement metadata checksumming, and we're only doing > > read-only access, so I think it would be reasonably safe to ignore > > metadata_csum_seed since we wouldn't do anything with it anyway. > > Is it incompat rather than ro_compat? If so, why? It's incompat, and I don't know. Maybe it's incompat but only if you implement metadata_csum (which would make sense). -- Colin Watson [cjwat...@debian.org] ___ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
