Subject: [bug#60442] [PATCH] bootloader: grub: Add support for root on lvm.

From: Maxim Cournoyer <[email-masked]>
Date: Tue, 21 Mar 2023 13:39:38 -0400

Hi Michael,

Michael Rohleder <[email-masked]> writes:

> This fixes <https://issues.guix.gnu.org/44877>.
>
> * gnu/bootloader/grub.scm (install-grub)
> (install-grub-efi)
> (install-grub-efi-removable)
> (install-grub-efi32): Add setting GRUB_PRELOAD_MODULES to lvm.
> * gnu/tests/install.scm (test-lvm-root-os): New variable.
> ---
>  gnu/bootloader/grub.scm |  9 +++++
>  gnu/tests/install.scm   | 81 ++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 89 insertions(+), 1 deletion(-)
>
> diff --git a/gnu/bootloader/grub.scm b/gnu/bootloader/grub.scm
> index ecd44e7f3c..1e2d142452 100644
> --- a/gnu/bootloader/grub.scm
> +++ b/gnu/bootloader/grub.scm
> @@ -9,6 +9,7 @@
>  ;;; Copyright © 2020 Stefan <[email-masked]>
>  ;;; Copyright © 2022 Karl Hallsby <[email-masked]>
>  ;;; Copyright © 2022 Denis 'GNUtoo' Carikli <[email-masked]>
> +;;; Copyright © 2022 Michael Rohleder <[email-masked]>
>  ;;;
>  ;;; This file is part of GNU Guix.
>  ;;;
> @@ -557,6 +558,8 @@ (define install-grub
>                ;; Tell 'grub-install' that there might be a LUKS-encrypted
>                ;; /boot or root partition.
>                (setenv "GRUB_ENABLE_CRYPTODISK" "y")
> +              ;; Let us boot from lvm
> +              (setenv "GRUB_PRELOAD_MODULES" "lvm")
>  
>                ;; Hide potentially confusing messages from the user, such as
>                ;; "Installing for i386-pc platform."
> @@ -629,6 +632,8 @@ (define install-grub-efi
>            ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
>            ;; root partition.
>            (setenv "GRUB_ENABLE_CRYPTODISK" "y")
> +          ;; Let us boot from lvm
> +          (setenv "GRUB_PRELOAD_MODULES" "lvm")
>            (invoke/quiet grub-install "--boot-directory" install-dir
>                          "--bootloader-id=Guix"
>                          "--efi-directory" target-esp)))))
> @@ -652,6 +657,8 @@ (define install-grub-efi-removable
>            ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
>            ;; root partition.
>            (setenv "GRUB_ENABLE_CRYPTODISK" "y")
> +          ;; Let us boot from lvm
> +          (setenv "GRUB_PRELOAD_MODULES" "lvm")
>            (invoke/quiet grub-install "--boot-directory" install-dir
>                          "--removable"
>                          ;; "--no-nvram"
> @@ -675,6 +682,8 @@ (define install-grub-efi32
>            ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
>            ;; root partition.
>            (setenv "GRUB_ENABLE_CRYPTODISK" "y")
> +          ;; Let us boot from lvm
> +          (setenv "GRUB_PRELOAD_MODULES" "lvm")
>            (invoke/quiet grub-install "--boot-directory" install-dir
>                          "--bootloader-id=Guix"
>  			(cond ((target-x86?) "--target=i386-efi")
> diff --git a/gnu/tests/install.scm b/gnu/tests/install.scm
> index 4e0e274e66..f9d34c1e28 100644
> --- a/gnu/tests/install.scm
> +++ b/gnu/tests/install.scm
> @@ -5,6 +5,7 @@
>  ;;; Copyright © 2020 Danny Milosavljevic <[email-masked]>
>  ;;; Copyright © 2020 Jan (janneke) Nieuwenhuizen <[email-masked]>
>  ;;; Copyright © 2020, 2021, 2022 Maxim Cournoyer <[email-masked]>
> +;;; Copyright © 2022 Michael Rohleder <[email-masked]>
>  ;;;
>  ;;; This file is part of GNU Guix.
>  ;;;
> @@ -76,6 +77,7 @@ (define-module (gnu tests install)
>              %test-jfs-root-os
>              %test-f2fs-root-os
>              %test-xfs-root-os
> +            %test-lvm-root-os
>              %test-lvm-separate-home-os
>  
>              %test-gui-installed-os
> @@ -831,7 +833,6 @@ (define %test-encrypted-root-os
>  ;;; Separate /home on LVM
>  ;;;
>  
> -;; Since LVM support in guix currently doesn't allow root-on-LVM we use /home on LVM
>  (define-os-with-source (%lvm-separate-home-os %lvm-separate-home-os-source)
>    (use-modules (gnu) (gnu tests))
>  
> @@ -913,6 +914,84 @@ (define %test-lvm-separate-home-os
>                        `(,@command) "lvm-separate-home-os")))))
>  
>  
> +
> +;;;
> +;;; LVM root device.
> +;;;
> +
> +(define-os-with-source (%lvm-root-os %lvm-root-os-source)
> +  (use-modules (gnu) (gnu tests))
> +
> +  (operating-system
> +    (host-name "root-os-on-lvm")
> +    (timezone "Europe/Paris")
> +    (locale "en_US.utf8")
> +
> +    (bootloader (bootloader-configuration
> +                 (bootloader grub-bootloader)
> +                 (targets (list "/dev/vdb"))))
> +    (kernel-arguments '("console=ttyS0"))
> +
> +    (mapped-devices (list (mapped-device
> +                           (source "vg0")
> +                           (target "vg0-root")
> +                           (type lvm-device-mapping))))
> +    (file-systems (cons* (file-system
> +                           (device "/dev/mapper/vg0-root")
> +                           (mount-point "/")
> +                           (type "ext4")
> +                           (dependencies mapped-devices))
> +                         %base-file-systems))
> +    (users %base-user-accounts)
> +    (services (cons (service marionette-service-type
> +                             (marionette-configuration
> +                              (imported-modules '((gnu services herd)
> +                                                  (guix combinators)))))
> +                    %base-services))))
> +
> +(define %lvm-root-os-installation-script
> +  "\
> +. /etc/profile
> +set -e -x
> +guix --version
> +
> +export GUIX_BUILD_OPTIONS=--no-grafts
> +parted --script /dev/vdb mklabel gpt \\
> +  mkpart primary ext2 1M 3M \\
> +  mkpart primary 3M 1.7G \\
> +  set 1 boot on \\
> +  set 1 bios_grub on
> +pvcreate /dev/vdb2
> +vgcreate vg0 /dev/vdb2
> +lvcreate -l 100%FREE -n root vg0
> +vgchange -ay
> +mkfs.ext4 -L root-fs /dev/mapper/vg0-root
> +mount /dev/mapper/vg0-root /mnt
> +herd start cow-store /mnt
> +mkdir /mnt/etc
> +cp /etc/target-config.scm /mnt/etc/config.scm
> +guix system init /mnt/etc/config.scm /mnt --no-substitutes
> +sync
> +reboot\n")
> +
> +(define %test-lvm-root-os
> +  (system-test
> +   (name "lvm-root-os")
> +   (description
> +    "Test functionality of an OS installed with a LVM / partition")
> +   (value
> +    (mlet* %store-monad ((image   (run-install %lvm-root-os
> +                                               %lvm-root-os-source
> +                                               #:script
> +                                               %lvm-root-os-installation-script
> +                                               #:packages (list lvm2-static)))
> +                         (command (qemu-command* image
> +                                                 #:memory-size 512)))
> +      (run-basic-test %lvm-root-os
> +                      `(,@command) "lvm-root-os")))))
> +
> +
> +

Thanks for this patch.  I've applied the change locally, and wanted to
see the test fail first, so I've reverted the following:

--8<---------------cut here---------------start------------->8---
Unstaged changes (1)
modified   gnu/bootloader/grub.scm
@@ -632,8 +632,6 @@ (define install-grub-efi
           ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
           ;; root partition.
           (setenv "GRUB_ENABLE_CRYPTODISK" "y")
-          ;; Let us boot from lvm
-          (setenv "GRUB_PRELOAD_MODULES" "lvm")
           (invoke/quiet grub-install "--boot-directory" install-dir
                         "--bootloader-id=Guix"
                         "--efi-directory" target-esp)))))
@@ -657,8 +655,6 @@ (define install-grub-efi-removable
           ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
           ;; root partition.
           (setenv "GRUB_ENABLE_CRYPTODISK" "y")
-          ;; Let us boot from lvm
-          (setenv "GRUB_PRELOAD_MODULES" "lvm")
           (invoke/quiet grub-install "--boot-directory" install-dir
                         "--removable"
                         ;; "--no-nvram"
@@ -682,8 +678,6 @@ (define install-grub-efi32
           ;; Tell 'grub-install' that there might be a LUKS-encrypted /boot or
           ;; root partition.
           (setenv "GRUB_ENABLE_CRYPTODISK" "y")
-          ;; Let us boot from lvm
-          (setenv "GRUB_PRELOAD_MODULES" "lvm")
           (invoke/quiet grub-install "--boot-directory" install-dir
                         "--bootloader-id=Guix"
 			(cond ((target-x86?) "--target=i386-efi")
--8<---------------cut here---------------end--------------->8---

And to my surprise 'make check-system TESTS=lvm-root-os' passed:

--8<---------------cut here---------------start------------->8---
%%%% Starting test basic  (Writing full log to "/gnu/store/m3rifzddpnc4x47r7nhfjkms97nzrc69-lvm-root-os/b)
marionette is ready
PASS: uname
PASS: shepherd socket ready
PASS: stdin is /dev/null
PASS: shell and user commands
PASS: special files
PASS: accounts

;;; (services (guix-daemon syslogd mcron console-font-tty3 file-system-/dev/shm console-font-tty5 file-sy)
PASS: shepherd services
PASS: libc honors /etc/localtime
PASS: /var/log/messages is not world-readable
PASS: homes
PASS: skeletons in home directories
PASS: permissions on /root
PASS: ownership and permissions of /var/empty
PASS: no extra home directories
PASS: login on tty1
PASS: getlogin on tty1
PASS: utmpx entry
PASS: wtmp entry
PASS: host name resolution
PASS: nscd configuration action
PASS: nscd invalidate action
SKIP: nscd invalidate action, wrong table
PASS: host not found
PASS: locale
PASS: /run/current-system is a GC root
PASS: /var/guix/gcroots/profiles is a valid symlink
PASS: guix-daemon set-http-proxy action
PASS: guix-daemon set-http-proxy action, clear
PASS: screendump
PASS: screen text
# of expected passes      29
# of skipped tests        1

Some deprecated features have been used.  Set the environment
variable GUILE_WARN_DEPRECATED to "detailed" and rerun the
program to get more information.  Set it to "no" to suppress
this message.
successfully built /gnu/store/69naxa7pcjlkn25xz033964z3vgp5c9d-lvm-root-os.drv
/gnu/store/m3rifzddpnc4x47r7nhfjkms97nzrc69-lvm-root-os
--8<---------------cut here---------------end--------------->8---

Are you sure this change is really needed?  Otherwise why would the test
pass even without the change?

-- 
Thanks,
Maxim