diff options
| -rw-r--r-- | doc/guix.texi | 104 | ||||
| -rw-r--r-- | gnu/bootloader/depthcharge.scm | 3 | ||||
| -rw-r--r-- | gnu/bootloader/extlinux.scm | 3 | ||||
| -rw-r--r-- | gnu/bootloader/grub.scm | 123 | ||||
| -rw-r--r-- | gnu/system.scm | 9 | ||||
| -rw-r--r-- | gnu/system/file-systems.scm | 55 | ||||
| -rw-r--r-- | gnu/tests/install.scm | 94 | ||||
| -rw-r--r-- | tests/file-systems.scm | 45 |
8 files changed, 385 insertions, 51 deletions
diff --git a/doc/guix.texi b/doc/guix.texi index 05f2d595b2..216422fe31 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -11782,6 +11782,110 @@ and unmount user-space FUSE file systems. This requires the @code{fuse.ko} kernel module to be loaded. @end defvr +@node Btrfs file system +@subsection Btrfs file system + +The Btrfs has special features, such as subvolumes, that merit being +explained in more details. The following section attempts to cover +basic as well as complex uses of a Btrfs file system with the Guix +System. + +In its simplest usage, a Btrfs file system can be described, for +example, by: + +@lisp +(file-system + (mount-point "/home") + (type "btrfs") + (device (file-system-label "my-home"))) +@end lisp + +The example below is more complex, as it makes use of a Btrfs +subvolume, named @code{rootfs}. The parent Btrfs file system is labeled +@code{my-btrfs-pool}, and is located on an encrypted device (hence the +dependency on @code{mapped-devices}): + +@lisp +(file-system + (device (file-system-label "my-btrfs-pool")) + (mount-point "/") + (type "btrfs") + (options "subvol=rootfs") + (dependencies mapped-devices)) +@end lisp + +Some bootloaders, for example GRUB, only mount a Btrfs partition at its +top level during the early boot, and rely on their configuration to +refer to the correct subvolume path within that top level. The +bootloaders operating in this way typically produce their configuration +on a running system where the Btrfs partitions are already mounted and +where the subvolume information is readily available. As an example, +@command{grub-mkconfig}, the configuration generator command shipped +with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level +path of a subvolume. + +The Guix System produces a bootloader configuration using the operating +system configuration as its sole input; it is therefore necessary to +extract the subvolume name on which @file{/gnu/store} lives (if any) +from that operating system configuration. To better illustrate, +consider a subvolume named 'rootfs' which contains the root file system +data. In such situation, the GRUB bootloader would only see the top +level of the root Btrfs partition, e.g.: + +@example +/ (top level) +├── rootfs (subvolume directory) + ├── gnu (normal directory) + ├── store (normal directory) +[...] +@end example + +Thus, the subvolume name must be prepended to the @file{/gnu/store} path +of the kernel, initrd binaries and any other files referred to in the +GRUB configuration that must be found during the early boot. + +The next example shows a nested hierarchy of subvolumes and +directories: + +@example +/ (top level) +├── rootfs (subvolume) + ├── gnu (normal directory) + ├── store (subvolume) +[...] +@end example + +This scenario would work without mounting the 'store' subvolume. +Mounting 'rootfs' is sufficient, since the subvolume name matches its +intended mount point in the file system hierarchy. Alternatively, the +'store' subvolume could be referred to by setting the @code{subvol} +option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}. + +Finally, a more contrived example of nested subvolumes: + +@example +/ (top level) +├── root-snapshots (subvolume) + ├── root-current (subvolume) + ├── guix-store (subvolume) +[...] +@end example + +Here, the 'guix-store' subvolume doesn't match its intended mount point, +so it is necessary to mount it. The subvolume must be fully specified, +by passing its file name to the @code{subvol} option. To illustrate, +the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using +a file system declaration such as: + +@lisp +(file-system + (device (file-system-label "btrfs-pool-1")) + (mount-point "/gnu/store") + (type "btrfs") + (options "subvol=root-snapshots/root-current/guix-store,\ +compress-force=zstd,space_cache=v2")) +@end lisp + @node Mapped Devices @section Mapped Devices diff --git a/gnu/bootloader/depthcharge.scm b/gnu/bootloader/depthcharge.scm index 58cc3f3932..0a50374bd9 100644 --- a/gnu/bootloader/depthcharge.scm +++ b/gnu/bootloader/depthcharge.scm @@ -82,7 +82,8 @@ (define* (depthcharge-configuration-file config entries #:key (system (%current-system)) - (old-entries '())) + (old-entries '()) + #:allow-other-keys) (match entries ((entry) (let ((kernel (menu-entry-linux entry)) diff --git a/gnu/bootloader/extlinux.scm b/gnu/bootloader/extlinux.scm index 5b4dd84965..6b5ff298e7 100644 --- a/gnu/bootloader/extlinux.scm +++ b/gnu/bootloader/extlinux.scm @@ -28,7 +28,8 @@ (define* (extlinux-configuration-file config entries #:key (system (%current-system)) - (old-entries '())) + (old-entries '()) + #:allow-other-keys) "Return the U-Boot configuration file corresponding to CONFIG, a <u-boot-configuration> object, and where the store is available at STORE-FS, a <file-system> object. OLD-ENTRIES is taken to be a list of menu entries diff --git a/gnu/bootloader/grub.scm b/gnu/bootloader/grub.scm index fb871c6e96..bb40c551a7 100644 --- a/gnu/bootloader/grub.scm +++ b/gnu/bootloader/grub.scm @@ -58,18 +58,29 @@ ;;; ;;; Code: -(define (strip-mount-point mount-point file) - "Strip MOUNT-POINT from FILE, which is a gexp or other lowerable object -denoting a file name." - (match mount-point - ((? string? mount-point) - (if (string=? mount-point "/") - file - #~(let ((file #$file)) - (if (string-prefix? #$mount-point file) - (substring #$file #$(string-length mount-point)) - file)))) - (#f file))) +(define* (normalize-file file mount-point btrfs-subvolume-file-name) + "Strip MOUNT-POINT and prepend BTRFS-SUBVOLUME-FILE-NAME to FILE, a +G-expression or other lowerable object denoting a file name." + + (define (strip-mount-point mount-point file) + (if mount-point + (if (string=? mount-point "/") + file + #~(let ((file #$file)) + (if (string-prefix? #$mount-point file) + (substring #$file #$(string-length mount-point)) + file))) + file)) + + (define (prepend-btrfs-subvolume-file-name btrfs-subvolume-file-name file) + (if btrfs-subvolume-file-name + #~(string-append #$btrfs-subvolume-file-name #$file) + file)) + + (prepend-btrfs-subvolume-file-name btrfs-subvolume-file-name + (strip-mount-point mount-point file))) + + (define-record-type* <grub-theme> ;; Default theme contributed by Felipe López. @@ -124,13 +135,14 @@ file with the resolution provided in CONFIG." (_ #f))))) (define* (eye-candy config store-device store-mount-point - #:key system port) - "Return a gexp that writes to PORT (a port-valued gexp) the -'grub.cfg' part concerned with graphics mode, background images, colors, and -all that. STORE-DEVICE designates the device holding the store, and -STORE-MOUNT-POINT is its mount point; these are used to determine where the -background image and fonts must be searched for. SYSTEM must be the target -system string---e.g., \"x86_64-linux\"." + #:key btrfs-store-subvolume-file-name system port) + "Return a gexp that writes to PORT (a port-valued gexp) the 'grub.cfg' part +concerned with graphics mode, background images, colors, and all that. +STORE-DEVICE designates the device holding the store, and STORE-MOUNT-POINT is +its mount point; these are used to determine where the background image and +fonts must be searched for. SYSTEM must be the target system string---e.g., +\"x86_64-linux\". BTRFS-STORE-SUBVOLUME-FILE-NAME is the file name of the +Btrfs subvolume, to be prepended to any store path, if any." (define setup-gfxterm-body (let ((gfxmode (or (and-let* ((theme (bootloader-configuration-theme config)) @@ -167,11 +179,14 @@ fi~%" #+font-file) (symbol->string (assoc-ref colors 'bg))))) (define font-file - (strip-mount-point store-mount-point - (file-append grub "/share/grub/unicode.pf2"))) + (normalize-file (file-append grub "/share/grub/unicode.pf2") + store-mount-point + btrfs-store-subvolume-file-name)) (define image - (grub-background-image config)) + (normalize-file (grub-background-image config) + store-mount-point + btrfs-store-subvolume-file-name)) (and image #~(format #$port " @@ -196,7 +211,7 @@ fi~%" #$(setup-gfxterm config font-file) #$(grub-setup-io config) - #$(strip-mount-point store-mount-point image) + #$image #$(theme-colors grub-theme-color-normal) #$(theme-colors grub-theme-color-highlight)))) @@ -304,52 +319,66 @@ code." (define* (grub-configuration-file config entries #:key (system (%current-system)) - (old-entries '())) + (old-entries '()) + btrfs-subvolume-file-name) "Return the GRUB configuration file corresponding to CONFIG, a <bootloader-configuration> object, and where the store is available at -STORE-FS, a <file-system> object. OLD-ENTRIES is taken to be a list of menu -entries corresponding to old generations of the system." +STORE-FS, a <file-system> object. OLD-ENTRIES is taken to be a list +of menu entries corresponding to old generations of the system. +BTRFS-SUBVOLUME-FILE-NAME may be used to specify on which subvolume a +Btrfs root file system resides." (define all-entries (append entries (bootloader-configuration-menu-entries config))) (define (menu-entry->gexp entry) - (let ((device (menu-entry-device entry)) - (device-mount-point (menu-entry-device-mount-point entry)) - (label (menu-entry-label entry)) - (kernel (menu-entry-linux entry)) - (arguments (menu-entry-linux-arguments entry)) - (initrd (menu-entry-initrd entry))) + (let* ((device (menu-entry-device entry)) + (device-mount-point (menu-entry-device-mount-point entry)) + (label (menu-entry-label entry)) + (arguments (menu-entry-linux-arguments entry)) + (kernel (normalize-file (menu-entry-linux entry) + device-mount-point + btrfs-subvolume-file-name)) + (initrd (normalize-file (menu-entry-initrd entry) + device-mount-point + btrfs-subvolume-file-name))) ;; Here DEVICE is the store and DEVICE-MOUNT-POINT is its mount point. ;; Use the right file names for KERNEL and INITRD in case ;; DEVICE-MOUNT-POINT is not "/", meaning that the store is on a ;; separate partition. - (let ((kernel (strip-mount-point device-mount-point kernel)) - (initrd (strip-mount-point device-mount-point initrd))) - #~(format port "menuentry ~s { + + ;; When BTRFS-SUBVOLUME-FILE-NAME is defined, prepend it the kernel and + ;; initrd paths, to allow booting from a Btrfs subvolume. + #~(format port "menuentry ~s { ~a linux ~a ~a initrd ~a }~%" - #$label - #$(grub-root-search device kernel) - #$kernel (string-join (list #$@arguments)) - #$initrd)))) + #$label + #$(grub-root-search device kernel) + #$kernel (string-join (list #$@arguments)) + #$initrd))) (define sugar (eye-candy config (menu-entry-device (first all-entries)) (menu-entry-device-mount-point (first all-entries)) + #:btrfs-store-subvolume-file-name btrfs-subvolume-file-name #:system system #:port #~port)) (define keyboard-layout-config - (let ((layout (bootloader-configuration-keyboard-layout config)) - (grub (bootloader-package - (bootloader-configuration-bootloader config)))) - #~(let ((keymap #$(and layout - (keyboard-layout-file layout #:grub grub)))) - (when keymap - (format port "\ + (let* ((layout (bootloader-configuration-keyboard-layout config)) + (grub (bootloader-package + (bootloader-configuration-bootloader config))) + (keymap* (and layout + (keyboard-layout-file layout #:grub grub))) + (keymap (and keymap* + (if btrfs-subvolume-file-name + #~(string-append #$btrfs-subvolume-file-name + #$keymap*) + keymap*)))) + #~(when #$keymap + (format port "\ insmod keylayouts -keymap ~a~%" keymap))))) +keymap ~a~%" #$keymap)))) (define builder #~(call-with-output-file #$output diff --git a/gnu/system.scm b/gnu/system.scm index cd75e4d4ba..d929187695 100644 --- a/gnu/system.scm +++ b/gnu/system.scm @@ -8,6 +8,7 @@ ;;; Copyright © 2020 Danny Milosavljevic <dannym@scratchpost.org> ;;; Copyright © 2020 Brice Waegeneire <brice@waegenei.re> ;;; Copyright © 2020 Florian Pelz <pelzflorian@pelzflorian.de> +;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com> ;;; ;;; This file is part of GNU Guix. ;;; @@ -1102,19 +1103,23 @@ entry." (define* (operating-system-bootcfg os #:optional (old-entries '())) "Return the bootloader configuration file for OS. Use OLD-ENTRIES, a list of <menu-entry>, to populate the \"old entries\" menu." - (let* ((root-fs (operating-system-root-file-system os)) + (let* ((file-systems (operating-system-file-systems os)) + (root-fs (operating-system-root-file-system os)) (root-device (file-system-device root-fs)) (params (operating-system-boot-parameters os root-device #:system-kernel-arguments? #t)) (entry (boot-parameters->menu-entry params)) (bootloader-conf (operating-system-bootloader os))) + (define generate-config-file (bootloader-configuration-file-generator (bootloader-configuration-bootloader bootloader-conf))) (generate-config-file bootloader-conf (list entry) - #:old-entries old-entries))) + #:old-entries old-entries + #:btrfs-subvolume-file-name + (btrfs-store-subvolume-file-name file-systems)))) (define* (operating-system-boot-parameters os root-device #:key system-kernel-arguments?) diff --git a/gnu/system/file-systems.scm b/gnu/system/file-systems.scm index 07f272db7c..0f94577760 100644 --- a/gnu/system/file-systems.scm +++ b/gnu/system/file-systems.scm @@ -22,7 +22,10 @@ #:use-module (ice-9 match) #:use-module (rnrs bytevectors) #:use-module (srfi srfi-1) + #:use-module (srfi srfi-2) #:use-module (srfi srfi-9) + #:use-module (srfi srfi-26) + #:use-module (srfi srfi-35) #:use-module (srfi srfi-9 gnu) #:use-module (guix records) #:use-module (gnu system uuid) @@ -49,6 +52,8 @@ file-system-location file-system-type-predicate + btrfs-subvolume? + btrfs-store-subvolume-file-name file-system-label file-system-label? @@ -566,4 +571,54 @@ system has the given TYPE." (lambda (fs) (string=? (file-system-type fs) type))) + +;;; +;;; Btrfs specific helpers. +;;; + +(define (btrfs-subvolume? fs) + "Predicate to check if FS, a file-system object, is a Btrfs subvolume." + (and-let* ((btrfs-file-system? (string= "btrfs" (file-system-type fs))) + (option-keys (map (match-lambda + ((key . value) key) + (key key)) + (file-system-options->alist + (file-system-options fs))))) + (find (cut string-prefix? "subvol" <>) option-keys))) + +(define (btrfs-store-subvolume-file-name file-systems) + "Return the subvolume file name within the Btrfs top level onto which the +store is located, else #f." + + (define (prepend-slash/maybe s) + (if (string=? "/" (string-take s 1)) + s + (string-append "/" s))) + + (define (file-name-depth file-name) + (length (string-tokenize file-name %not-slash))) + + (and-let* ((btrfs-subvolume-fs (filter btrfs-subvolume? file-systems)) + (btrfs-subvolume-fs* + (sort btrfs-subvolume-fs + (lambda (fs1 fs2) + (> (file-name-depth (file-system-mount-point fs1)) + (file-name-depth (file-system-mount-point fs2)))))) + (store-subvolume-fs + (find (lambda (fs) (file-prefix? (file-system-mount-point fs) + (%store-prefix))) + btrfs-subvolume-fs*)) + (options (file-system-options->alist + (file-system-options store-subvolume-fs)))) + ;; XXX: Deriving the subvolume name based from a subvolume ID is not + ;; supported, as we'd need to query the actual file system. + (or (and=> (assoc-ref options "subvol") prepend-slash/maybe) + ;; FIXME: Use &fix-hint once it no longer pulls in (guix utils). + (raise (condition + (&message + (message "The store is on a Btrfs subvolume, but the \ +subvolume name is unknown. +Hint: Use the \"subvol\" Btrfs file system option."))))))) + + ;;; file-systems.scm ends here diff --git a/gnu/tests/install.scm b/gnu/tests/install.scm index 94d970e1cc..cea26c8ef3 100644 --- a/gnu/tests/install.scm +++ b/gnu/tests/install.scm @@ -61,6 +61,7 @@ %test-raid-root-os %test-encrypted-root-os %test-btrfs-root-os + %test-btrfs-root-on-subvolume-os %test-jfs-root-os %test-f2fs-root-os @@ -865,6 +866,99 @@ build (current-guix) and then store a couple of full system images.") ;;; +;;; Btrfs root file system on a subvolume. +;;; + +(define-os-with-source (%btrfs-root-on-subvolume-os + %btrfs-root-on-subvolume-os-source) + ;; The OS we want to install. + (use-modules (gnu) (gnu tests) (srfi srfi-1)) + + (operating-system + (host-name "hurd") + (timezone "America/Montreal") + (locale "en_US.UTF-8") + (bootloader (bootloader-configuration + (bootloader grub-bootloader) + (target "/dev/vdb"))) + (kernel-arguments '("console=ttyS0")) + (file-systems (cons* (file-system + (device (file-system-label "btrfs-pool")) + (mount-point "/") + (options "subvol=rootfs,compress=zstd") + (type "btrfs")) + (file-system + (device (file-system-label "btrfs-pool")) + (mount-point "/home") + (options "subvol=homefs,compress=lzo") + (type "btrfs")) + %base-file-systems)) + (users (cons (user-account + (name "charlie") + (group "users") + (supplementary-groups '("wheel" "audio" "video"))) + %base-user-accounts)) + (services (cons (service marionette-service-type + (marionette-configuration + (imported-modules '((gnu services herd) + (guix combinators))))) + %base-services)))) + +(define %btrfs-root-on-subvolume-installation-script + ;; Shell script of a simple installation. + "\ +. /etc/profile +set -e -x +guix --version + +export GUIX_BUILD_OPTIONS=--no-grafts +ls -l /run/current-system/gc-roots +parted --script /dev/vdb mklabel gpt \\ + mkpart primary ext2 1M 3M \\ + mkpart primary ext2 3M 2G \\ + set 1 boot on \\ + set 1 bios_grub on + +# Setup the top level Btrfs file system with its subvolume. +mkfs.btrfs -L btrfs-pool /dev/vdb2 +mount /dev/vdb2 /mnt +btrfs subvolume create /mnt/rootfs +btrfs subvolume create /mnt/homefs +umount /dev/vdb2 + +# Mount the subvolumes, ready for installation. +mount LABEL=btrfs-pool -o 'subvol=rootfs,compress=zstd' /mnt +mkdir /mnt/home +mount LABEL=btrfs-pool -o 'subvol=homefs,compress=zstd' /mnt/home + +herd start cow-store /mnt +mkdir /mnt/etc +cp /etc/target-config.scm /mnt/etc/config.scm +guix system build /mnt/etc/config.scm +guix system init /mnt/etc/config.scm /mnt --no-substitutes +sync +reboot\n") + +(define %test-btrfs-root-on-subvolume-os + (system-test + (name "btrfs-root-on-subvolume-os") + (description + "Test basic functionality of an OS installed like one would do by hand. +This test is expensive in terms of CPU and storage usage since we need to +build (current-guix) and then store a couple of full system images.") + (value + (mlet* %store-monad + ((image + (run-install %btrfs-root-on-subvolume-os + %btrfs-root-on-subvolume-os-source + #:script + %btrfs-root-on-subvolume-installation-script)) + (command (qemu-command/writable-image image))) + (run-basic-test %btrfs-root-on-subvolume-os command + "btrfs-root-on-subvolume-os"))))) + + +;;; ;;; JFS root file system. ;;; diff --git a/tests/file-systems.scm b/tests/file-systems.scm index 41f1021067..7f7c373884 100644 --- a/tests/file-systems.scm +++ b/tests/file-systems.scm @@ -83,4 +83,49 @@ #f (alist->file-system-options '())) + +;;; +;;; Btrfs related. +;;; + +(define %btrfs-root-subvolume + (file-system + (device (file-system-label "btrfs-pool")) + (mount-point "/") + (type "btrfs") + (options "subvol=rootfs,compress=zstd"))) + +(define %btrfs-store-subvolid + (file-system + (device (file-system-label "btrfs-pool")) + (mount-point "/gnu/store") + (type "btrfs") + (options "subvolid=10,compress=zstd") + (dependencies (list %btrfs-root-subvolume)))) + +(define %btrfs-store-subvolume + (file-system + (device (file-system-label "btrfs-pool")) + (mount-point "/gnu/store") + (type "btrfs") + (options "subvol=/some/nested/file/name") + (dependencies (list %btrfs-root-subvolume)))) + +(test-assert "btrfs-subvolume? (subvol)" + (btrfs-subvolume? %btrfs-root-subvolume)) + +(test-assert "btrfs-subvolume? (subvolid)" + (btrfs-subvolume? %btrfs-store-subvolid)) + +(test-equal "btrfs-store-subvolume-file-name" + "/some/nested/file/name" + (parameterize ((%store-prefix "/gnu/store")) + (btrfs-store-subvolume-file-name (list %btrfs-root-subvolume + %btrfs-store-subvolume)))) + +(test-error "btrfs-store-subvolume-file-name (subvolid)" + (parameterize ((%store-prefix "/gnu/store")) + (btrfs-store-subvolume-file-name (list %btrfs-root-subvolume + %btrfs-store-subvolid)))) + (test-end) |