240 lines
9.5 KiB
Scheme
240 lines
9.5 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
||
;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
|
||
;;; Copyright © 2016 Andreas Enge <andreas@enge.fr>
|
||
;;; Copyright © 2017 Mark H Weaver <mhw@netris.org>
|
||
;;;
|
||
;;; This file is part of GNU Guix.
|
||
;;;
|
||
;;; GNU Guix is free software; you can redistribute it and/or modify it
|
||
;;; under the terms of the GNU General Public License as published by
|
||
;;; the Free Software Foundation; either version 3 of the License, or (at
|
||
;;; your option) any later version.
|
||
;;;
|
||
;;; GNU Guix is distributed in the hope that it will be useful, but
|
||
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
;;; GNU General Public License for more details.
|
||
;;;
|
||
;;; You should have received a copy of the GNU General Public License
|
||
;;; 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)
|
||
#:use-module (guix modules)
|
||
#:use-module (guix i18n)
|
||
#:use-module ((guix utils)
|
||
#:select (source-properties->location
|
||
&error-location))
|
||
#: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)
|
||
(device-module-aliases matching-modules)
|
||
#:autoload (gnu packages cryptsetup) (cryptsetup-static)
|
||
#:autoload (gnu packages linux) (mdadm-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)
|
||
#:export (mapped-device
|
||
mapped-device?
|
||
mapped-device-source
|
||
mapped-device-target
|
||
mapped-device-type
|
||
mapped-device-location
|
||
|
||
mapped-device-kind
|
||
mapped-device-kind?
|
||
mapped-device-kind-open
|
||
mapped-device-kind-close
|
||
mapped-device-kind-check
|
||
|
||
device-mapping-service-type
|
||
device-mapping-service
|
||
|
||
luks-device-mapping
|
||
raid-device-mapping))
|
||
|
||
;;; Commentary:
|
||
;;;
|
||
;;; This module supports "device mapping", a concept implemented by Linux's
|
||
;;; device-mapper.
|
||
;;;
|
||
;;; Code:
|
||
|
||
(define-record-type* <mapped-device> mapped-device
|
||
make-mapped-device
|
||
mapped-device?
|
||
(source mapped-device-source) ;string | list of strings
|
||
(target mapped-device-target) ;string
|
||
(type mapped-device-type) ;<mapped-device-kind>
|
||
(location mapped-device-location
|
||
(default (current-source-location)) (innate)))
|
||
|
||
(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))))
|
||
(check mapped-device-kind-check ;source -> Boolean
|
||
(default (const #t))))
|
||
|
||
|
||
;;;
|
||
;;; Device mapping as a Shepherd service.
|
||
;;;
|
||
|
||
(define device-mapping-service-type
|
||
(shepherd-service-type
|
||
'device-mapping
|
||
(match-lambda
|
||
(($ <mapped-device> source target
|
||
($ <mapped-device-type> open close))
|
||
(shepherd-service
|
||
(provision (list (symbol-append 'device-mapping- (string->symbol target))))
|
||
(requirement '(udev))
|
||
(documentation "Map a device node using Linux's device mapper.")
|
||
(start #~(lambda () #$(open source target)))
|
||
(stop #~(lambda _ (not #$(close source target))))
|
||
(respawn? #f))))))
|
||
|
||
(define (device-mapping-service mapped-device)
|
||
"Return a service that sets up @var{mapped-device}."
|
||
(service device-mapping-service-type mapped-device))
|
||
|
||
|
||
;;;
|
||
;;; Common device mappings.
|
||
;;;
|
||
|
||
(define (open-luks-device source target)
|
||
"Return a gexp that maps SOURCE to TARGET as a LUKS device, using
|
||
'cryptsetup'."
|
||
(with-imported-modules (source-module-closure
|
||
'((gnu build file-systems)))
|
||
#~(let ((source #$(if (uuid? source)
|
||
(uuid-bytevector source)
|
||
source)))
|
||
;; XXX: 'use-modules' should be at the top level.
|
||
(use-modules (rnrs bytevectors) ;bytevector?
|
||
((gnu build file-systems)
|
||
#:select (find-partition-by-luks-uuid)))
|
||
|
||
;; Use 'cryptsetup-static', not 'cryptsetup', to avoid pulling the
|
||
;; whole world inside the initrd (for when we're in an initrd).
|
||
(zero? (system* #$(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)
|
||
|
||
#$target)))))
|
||
|
||
(define (close-luks-device source target)
|
||
"Return a gexp that closes TARGET, a LUKS device."
|
||
#~(zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup")
|
||
"close" #$target)))
|
||
|
||
(define (check-device-initrd-modules device linux-modules location)
|
||
"Raise an error if DEVICE needs modules beyond LINUX-MODULES to operate.
|
||
DEVICE must be a \"/dev\" file name."
|
||
(let ((modules (delete-duplicates
|
||
(append-map matching-modules
|
||
(device-module-aliases device)))))
|
||
(unless (every (cute member <> linux-modules) modules)
|
||
(raise (condition
|
||
(&message
|
||
(message (format #f (G_ "you may need these modules \
|
||
in the initrd for ~a:~{ ~a~}")
|
||
device modules)))
|
||
(&error-location
|
||
(location (source-properties->location location))))))))
|
||
|
||
(define* (check-luks-device md #:key
|
||
needed-for-boot?
|
||
(initrd-modules '())
|
||
#:allow-other-keys
|
||
#:rest rest)
|
||
"Ensure the source of MD is valid."
|
||
(let ((source (mapped-device-source md))
|
||
(location (mapped-device-location md)))
|
||
(or (not (zero? (getuid)))
|
||
(if (uuid? source)
|
||
(match (find-partition-by-luks-uuid (uuid-bytevector source))
|
||
(#f
|
||
(raise (condition
|
||
(&message
|
||
(message (format #f (G_ "no LUKS partition with UUID '~a'")
|
||
(uuid->string source))))
|
||
(&error-location
|
||
(location (source-properties->location
|
||
(mapped-device-location md)))))))
|
||
((? string? device)
|
||
(check-device-initrd-modules device initrd-modules location)))
|
||
(check-device-initrd-modules source initrd-modules location)))))
|
||
|
||
(define luks-device-mapping
|
||
;; The type of LUKS mapped devices.
|
||
(mapped-device-kind
|
||
(open open-luks-device)
|
||
(close close-luks-device)
|
||
(check check-luks-device)))
|
||
|
||
(define (open-raid-device sources target)
|
||
"Return a gexp that assembles SOURCES (a list of devices) to the RAID device
|
||
TARGET (e.g., \"/dev/md0\"), using 'mdadm'."
|
||
#~(let ((sources '#$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 target)
|
||
"Return a gexp that stops the RAID device 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)))
|
||
|
||
;;; mapped-devices.scm ends here
|