;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014-2022 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2016 Andreas Enge <andreas@enge.fr>
+;;; Copyright © 2017, 2018 Mark H Weaver <mhw@netris.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu system mapped-devices)
+ #:use-module (guix gexp)
#:use-module (guix records)
- #:export (mapped-device
+ #:use-module ((guix modules) #:hide (file-name->module-name))
+ #:use-module (guix i18n)
+ #:use-module ((guix diagnostics)
+ #:select (source-properties->location
+ formatted-message
+ &fix-hint
+ &error-location))
+ #:use-module (guix deprecation)
+ #:use-module (gnu services)
+ #:use-module (gnu services shepherd)
+ #:use-module (gnu system uuid)
+ #:autoload (gnu build file-systems) (find-partition-by-luks-uuid)
+ #:autoload (gnu build linux-modules)
+ (missing-modules)
+ #:autoload (gnu packages cryptsetup) (cryptsetup-static)
+ #:autoload (gnu packages linux) (mdadm-static lvm2-static)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:use-module (srfi srfi-34)
+ #:use-module (srfi srfi-35)
+ #:use-module (ice-9 match)
+ #:use-module (ice-9 format)
+ #:export (%mapped-device
+ mapped-device
mapped-device?
mapped-device-source
mapped-device-target
+ mapped-device-targets
mapped-device-type
+ mapped-device-location
mapped-device-kind
mapped-device-kind?
mapped-device-kind-open
- mapped-device-kind-close))
+ mapped-device-kind-close
+ mapped-device-kind-check
+
+ device-mapping-service-type
+ device-mapping-service
+
+ check-device-initrd-modules ;XXX: needs a better place
+
+ luks-device-mapping
+ raid-device-mapping
+ lvm-device-mapping))
;;; Commentary:
;;;
;;;
;;; Code:
-(define-record-type* <mapped-device> mapped-device
+(define-record-type* <mapped-device> %mapped-device
make-mapped-device
mapped-device?
- (source mapped-device-source) ;string
- (target mapped-device-target) ;string
- (type mapped-device-type)) ;<mapped-device-kind>
+ (source mapped-device-source) ;string | list of strings
+ (targets mapped-device-targets) ;list of strings
+ (type mapped-device-type) ;<mapped-device-kind>
+ (location mapped-device-location
+ (default (current-source-location)) (innate)))
+
+(define-syntax mapped-device-compatibility-helper
+ (syntax-rules (target)
+ ((_ () (fields ...))
+ (%mapped-device fields ...))
+ ((_ ((target exp) rest ...) (others ...))
+ (%mapped-device others ...
+ (targets (list exp))
+ rest ...))
+ ((_ (field rest ...) (others ...))
+ (mapped-device-compatibility-helper (rest ...)
+ (others ... field)))))
+
+(define-syntax-rule (mapped-device fields ...)
+ "Build an <mapped-device> record, automatically converting 'target' field
+specifications to 'targets'."
+ (mapped-device-compatibility-helper (fields ...) ()))
+
+(define-deprecated (mapped-device-target md)
+ mapped-device-targets
+ (car (mapped-device-targets md)))
(define-record-type* <mapped-device-type> mapped-device-kind
make-mapped-device-kind
mapped-device-kind?
(open mapped-device-kind-open) ;source target -> gexp
(close mapped-device-kind-close ;source target -> gexp
- (default (const #~(const #f)))))
+ (default (const #~(const #f))))
+ (check mapped-device-kind-check ;source -> Boolean
+ (default (const #t))))
+
+\f
+;;;
+;;; Device mapping as a Shepherd service.
+;;;
+
+(define device-mapping-service-type
+ (shepherd-service-type
+ 'device-mapping
+ (match-lambda
+ (($ <mapped-device> source targets
+ ($ <mapped-device-type> open close))
+ (shepherd-service
+ (provision (list (symbol-append 'device-mapping- (string->symbol (string-join targets "-")))))
+ (requirement '(udev))
+ (documentation "Map a device node using Linux's device mapper.")
+ (start #~(lambda () #$(open source targets)))
+ (stop #~(lambda _ (not #$(close source targets))))
+ (respawn? #f))))
+ (description "Map a device node using Linux's device mapper.")))
+
+(define (device-mapping-service mapped-device)
+ "Return a service that sets up @var{mapped-device}."
+ (service device-mapping-service-type mapped-device))
+
+\f
+;;;
+;;; Static checks.
+;;;
+
+(define (check-device-initrd-modules device linux-modules location)
+ "Raise an error if DEVICE needs modules beyond LINUX-MODULES to operate.
+DEVICE must be a \"/dev\" file name."
+ (define missing
+ ;; Attempt to determine missing modules.
+ (catch 'system-error
+ (lambda ()
+ (missing-modules device linux-modules))
+
+ ;; If we can't do that (e.g., EPERM), skip the whole thing.
+ (const '())))
+
+ (unless (null? missing)
+ ;; Note: What we suggest here is a list of module names (e.g.,
+ ;; "usb_storage"), not file names (e.g., "usb-storage.ko"). This is
+ ;; OK because we have machinery that accepts both the hyphen and the
+ ;; underscore version.
+ (raise (make-compound-condition
+ (formatted-message (G_ "you may need these modules \
+in the initrd for ~a:~{ ~a~}")
+ device missing)
+ (condition
+ (&fix-hint
+ (hint (format #f (G_ "Try adding them to the
+@code{initrd-modules} field of your @code{operating-system} declaration, along
+these lines:
+
+@example
+ (operating-system
+ ;; @dots{}
+ (initrd-modules (append (list~{ ~s~})
+ %base-initrd-modules)))
+@end example
+
+If you think this diagnostic is inaccurate, use the @option{--skip-checks}
+option of @command{guix system}.\n")
+ missing))))
+ (condition
+ (&error-location
+ (location (source-properties->location location))))))))
+
+\f
+;;;
+;;; Common device mappings.
+;;;
+
+(define (open-luks-device source targets)
+ "Return a gexp that maps SOURCE to TARGET as a LUKS device, using
+'cryptsetup'."
+ (with-imported-modules (source-module-closure
+ '((gnu build file-systems)
+ (guix build utils))) ;; For mkdir-p
+ (match targets
+ ((target)
+ #~(let ((source #$(if (uuid? source)
+ (uuid-bytevector source)
+ source)))
+ ;; XXX: 'use-modules' should be at the top level.
+ (use-modules (rnrs bytevectors) ;bytevector?
+ ((gnu build file-systems)
+ #:select (find-partition-by-luks-uuid
+ system*/tty))
+ ((guix build utils) #:select (mkdir-p)))
+
+ ;; Create '/run/cryptsetup/' if it does not exist, as device locking
+ ;; is mandatory for LUKS2.
+ (mkdir-p "/run/cryptsetup/")
+
+ ;; Use 'cryptsetup-static', not 'cryptsetup', to avoid pulling the
+ ;; whole world inside the initrd (for when we're in an initrd).
+ ;; 'cryptsetup open' requires standard input to be a tty to allow
+ ;; for interaction but shepherd sets standard input to /dev/null;
+ ;; thus, explicitly request a tty.
+ (zero? (system*/tty
+ #$(file-append cryptsetup-static "/sbin/cryptsetup")
+ "open" "--type" "luks"
+
+ ;; Note: We cannot use the "UUID=source" syntax here
+ ;; because 'cryptsetup' implements it by searching the
+ ;; udev-populated /dev/disk/by-id directory but udev may
+ ;; be unavailable at the time we run this.
+ (if (bytevector? source)
+ (or (let loop ((tries-left 10))
+ (and (positive? tries-left)
+ (or (find-partition-by-luks-uuid source)
+ ;; If the underlying partition is
+ ;; not found, try again after
+ ;; waiting a second, up to ten
+ ;; times. FIXME: This should be
+ ;; dealt with in a more robust way.
+ (begin (sleep 1)
+ (loop (- tries-left 1))))))
+ (error "LUKS partition not found" source))
+ source)
+
+ #$target)))))))
+
+(define (close-luks-device source targets)
+ "Return a gexp that closes TARGET, a LUKS device."
+ (match targets
+ ((target)
+ #~(zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup")
+ "close" #$target)))))
+
+(define* (check-luks-device md #:key
+ needed-for-boot?
+ (initrd-modules '())
+ #:allow-other-keys
+ #:rest rest)
+ "Ensure the source of MD is valid."
+ (let ((source (mapped-device-source md))
+ (location (mapped-device-location md)))
+ (or (not (zero? (getuid)))
+ (if (uuid? source)
+ (match (find-partition-by-luks-uuid (uuid-bytevector source))
+ (#f
+ (raise (make-compound-condition
+ (formatted-message (G_ "no LUKS partition with UUID '~a'")
+ (uuid->string source))
+ (condition
+ (&error-location
+ (location (source-properties->location
+ (mapped-device-location md))))))))
+ ((? string? device)
+ (check-device-initrd-modules device initrd-modules location)))
+ (check-device-initrd-modules source initrd-modules location)))))
+
+(define luks-device-mapping
+ ;; The type of LUKS mapped devices.
+ (mapped-device-kind
+ (open open-luks-device)
+ (close close-luks-device)
+ (check check-luks-device)))
+
+(define (open-raid-device sources targets)
+ "Return a gexp that assembles SOURCES (a list of devices) to the RAID device
+TARGET (e.g., \"/dev/md0\"), using 'mdadm'."
+ (match targets
+ ((target)
+ #~(let ((sources '#$sources)
+
+ ;; XXX: We're not at the top level here. We could use a
+ ;; non-top-level 'use-modules' form but that doesn't work when the
+ ;; code is eval'd, like the Shepherd does.
+ (every (@ (srfi srfi-1) every))
+ (format (@ (ice-9 format) format)))
+ (let loop ((attempts 0))
+ (unless (every file-exists? sources)
+ (when (> attempts 20)
+ (error "RAID devices did not show up; bailing out"
+ sources))
+
+ (format #t "waiting for RAID source devices~{ ~a~}...~%"
+ sources)
+ (sleep 1)
+ (loop (+ 1 attempts))))
+
+ ;; Use 'mdadm-static' rather than 'mdadm' to avoid pulling its whole
+ ;; closure (80 MiB) in the initrd when a RAID device is needed for boot.
+ (zero? (apply system* #$(file-append mdadm-static "/sbin/mdadm")
+ "--assemble" #$target sources))))))
+
+(define (close-raid-device sources targets)
+ "Return a gexp that stops the RAID device TARGET."
+ (match targets
+ ((target)
+ #~(zero? (system* #$(file-append mdadm-static "/sbin/mdadm")
+ "--stop" #$target)))))
+
+(define raid-device-mapping
+ ;; The type of RAID mapped devices.
+ (mapped-device-kind
+ (open open-raid-device)
+ (close close-raid-device)))
+
+(define (open-lvm-device source targets)
+ #~(and
+ (zero? (system* #$(file-append lvm2-static "/sbin/lvm")
+ "vgchange" "--activate" "ay" #$source))
+ ; /dev/mapper nodes are usually created by udev, but udev may be unavailable at the time we run this. So we create them here.
+ (zero? (system* #$(file-append lvm2-static "/sbin/lvm")
+ "vgscan" "--mknodes"))
+ (every file-exists? (map (lambda (file) (string-append "/dev/mapper/" file))
+ '#$targets))))
+
+
+(define (close-lvm-device source targets)
+ #~(zero? (system* #$(file-append lvm2-static "/sbin/lvm")
+ "vgchange" "--activate" "n" #$source)))
+
+(define lvm-device-mapping
+ (mapped-device-kind
+ (open open-lvm-device)
+ (close close-lvm-device)))
;;; mapped-devices.scm ends here
HCoop / jackhill / guix / guix.git / blobdiff