Tested with (locally fixed) lvm-separate-home-os system test. * gnu/system/mapped-devices.scm (lvm-device-mapping): Add SRFI-1 to modules. Change-Id: I8c155b47c29004bdc59057391dfba94ce33bdbc2
		
			
				
	
	
		
			359 lines
		
	
	
	
		
			14 KiB
		
	
	
	
		
			Scheme
		
	
	
	
	
	
			
		
		
	
	
			359 lines
		
	
	
	
		
			14 KiB
		
	
	
	
		
			Scheme
		
	
	
	
	
	
| ;;; GNU Guix --- Functional package management for GNU
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| ;;; Copyright © 2014-2022, 2024 Ludovic Courtès <ludo@gnu.org>
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| ;;; Copyright © 2016 Andreas Enge <andreas@enge.fr>
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| ;;; Copyright © 2017, 2018 Mark H Weaver <mhw@netris.org>
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| ;;; Copyright © 2024 Tomas Volf <~@wolfsden.cz>
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| ;;;
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| ;;; This file is part of GNU Guix.
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| ;;;
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| ;;; GNU Guix is free software; you can redistribute it and/or modify it
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| ;;; under the terms of the GNU General Public License as published by
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| ;;; the Free Software Foundation; either version 3 of the License, or (at
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| ;;; your option) any later version.
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| ;;;
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| ;;; GNU Guix is distributed in the hope that it will be useful, but
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| ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
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| ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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| ;;; GNU General Public License for more details.
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| ;;;
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| ;;; You should have received a copy of the GNU General Public License
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| ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
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| 
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| (define-module (gnu system mapped-devices)
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|   #:use-module (guix gexp)
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|   #:use-module (guix records)
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|   #:use-module ((guix modules) #:hide (file-name->module-name))
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|   #:use-module (guix i18n)
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|   #:use-module ((guix diagnostics)
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|                 #:select (source-properties->location
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|                           formatted-message
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|                           &fix-hint
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|                           &error-location))
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|   #:use-module (guix deprecation)
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|   #:use-module (gnu services)
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|   #:use-module (gnu services shepherd)
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|   #:use-module (gnu system uuid)
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|   #:autoload   (gnu build file-systems) (find-partition-by-luks-uuid)
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|   #:autoload   (gnu build linux-modules)
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|                  (missing-modules)
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|   #:autoload   (gnu packages cryptsetup) (cryptsetup-static)
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|   #:autoload   (gnu packages linux) (mdadm-static lvm2-static)
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|   #:use-module (srfi srfi-1)
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|   #:use-module (srfi srfi-26)
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|   #:use-module (srfi srfi-34)
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|   #:use-module (srfi srfi-35)
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|   #:use-module (ice-9 match)
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|   #:use-module (ice-9 format)
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|   #:export (%mapped-device
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|             mapped-device
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|             mapped-device?
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|             mapped-device-source
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|             mapped-device-target
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|             mapped-device-targets
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|             mapped-device-type
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|             mapped-device-location
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| 
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|             mapped-device-kind
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|             mapped-device-kind?
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|             mapped-device-kind-open
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|             mapped-device-kind-close
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|             mapped-device-kind-modules
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|             mapped-device-kind-check
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| 
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|             device-mapping-service-type
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|             device-mapping-service
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| 
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|             check-device-initrd-modules           ;XXX: needs a better place
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| 
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|             luks-device-mapping
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|             luks-device-mapping-with-options
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|             raid-device-mapping
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|             lvm-device-mapping))
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| 
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| ;;; Commentary:
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| ;;;
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| ;;; This module supports "device mapping", a concept implemented by Linux's
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| ;;; device-mapper.
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| ;;;
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| ;;; Code:
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| 
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| (define-record-type* <mapped-device> %mapped-device
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|   make-mapped-device
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|   mapped-device?
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|   (source    mapped-device-source)                ;string | list of strings
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|   (targets   mapped-device-targets)               ;list of strings
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|   (type      mapped-device-type)                  ;<mapped-device-kind>
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|   (location  mapped-device-location
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|              (default (current-source-location)) (innate)))
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| 
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| (define-syntax mapped-device-compatibility-helper
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|   (syntax-rules (target)
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|     ((_ () (fields ...))
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|      (%mapped-device fields ...))
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|     ((_ ((target exp) rest ...) (others ...))
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|      (%mapped-device others ...
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|                       (targets (list exp))
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|                       rest ...))
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|     ((_ (field rest ...) (others ...))
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|      (mapped-device-compatibility-helper (rest ...)
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|                                          (others ... field)))))
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| 
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| (define-syntax-rule (mapped-device fields ...)
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|   "Build an <mapped-device> record, automatically converting 'target' field
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| specifications to 'targets'."
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|   (mapped-device-compatibility-helper (fields ...) ()))
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| 
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| (define-deprecated (mapped-device-target md)
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|   mapped-device-targets
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|   (car (mapped-device-targets md)))
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| 
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| (define-record-type* <mapped-device-type> mapped-device-kind
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|   make-mapped-device-kind
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|   mapped-device-kind?
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|   (open      mapped-device-kind-open)             ;source target -> gexp
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|   (close     mapped-device-kind-close             ;source target -> gexp
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|              (default (const #~(const #f))))
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|   (modules   mapped-device-kind-modules           ;list of module names
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|              (default '()))
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|   (check     mapped-device-kind-check             ;source -> Boolean
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|              (default (const #t))))
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| 
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| 
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| ;;;
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| ;;; Device mapping as a Shepherd service.
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| ;;;
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| 
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| (define device-mapping-service-type
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|   (shepherd-service-type
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|    'device-mapping
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|    (match-lambda
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|      (($ <mapped-device> source targets
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|                          ($ <mapped-device-type> open close modules))
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|       (shepherd-service
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|        (provision (list (symbol-append 'device-mapping- (string->symbol (string-join targets "-")))))
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|        (requirement '(udev))
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|        (documentation "Map a device node using Linux's device mapper.")
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|        (start #~(lambda () #$(open source targets)))
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|        (stop #~(lambda _ (not #$(close source targets))))
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|        (modules (append %default-modules modules))
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|        (respawn? #f))))
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|    (description "Map a device node using Linux's device mapper.")))
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| 
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| (define (device-mapping-service mapped-device)
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|   "Return a service that sets up @var{mapped-device}."
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|   (service device-mapping-service-type mapped-device))
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| 
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| 
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| ;;;
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| ;;; Static checks.
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| ;;;
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| 
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| (define (check-device-initrd-modules device linux-modules location)
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|   "Raise an error if DEVICE needs modules beyond LINUX-MODULES to operate.
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| DEVICE must be a \"/dev\" file name."
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|   (define missing
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|     ;; Attempt to determine missing modules.
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|     (catch 'system-error
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|       (lambda ()
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|         (missing-modules device linux-modules))
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| 
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|       ;; If we can't do that (e.g., EPERM), skip the whole thing.
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|       (const '())))
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| 
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|   (unless (null? missing)
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|     ;; Note: What we suggest here is a list of module names (e.g.,
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|     ;; "usb_storage"), not file names (e.g., "usb-storage.ko").  This is
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|     ;; OK because we have machinery that accepts both the hyphen and the
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|     ;; underscore version.
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|     (raise (make-compound-condition
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|             (formatted-message (G_ "you may need these modules \
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| in the initrd for ~a:~{ ~a~}")
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|                                device missing)
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|             (condition
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|              (&fix-hint
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|               (hint (format #f (G_ "Try adding them to the
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| @code{initrd-modules} field of your @code{operating-system} declaration, along
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| these lines:
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| 
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| @example
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|  (operating-system
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|    ;; @dots{}
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|    (initrd-modules (append (list~{ ~s~})
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|                            %base-initrd-modules)))
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| @end example
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| 
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| If you think this diagnostic is inaccurate, use the @option{--skip-checks}
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| option of @command{guix system}.\n")
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|                             missing))))
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|             (condition
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|              (&error-location
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|               (location (source-properties->location location))))))))
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| 
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| 
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| ;;;
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| ;;; Common device mappings.
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| ;;;
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| 
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| (define* (open-luks-device source targets #:key key-file)
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|   "Return a gexp that maps SOURCE to TARGET as a LUKS device, using
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| 'cryptsetup'."
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|   (with-imported-modules (source-module-closure
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|                           '((gnu build file-systems)
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|                             (guix build utils))) ;; For mkdir-p
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|     (match targets
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|       ((target)
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|        #~(let ((source #$(if (uuid? source)
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|                              (uuid-bytevector source)
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|                              source))
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|                (keyfile #$key-file))
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| 
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|            ;; Create '/run/cryptsetup/' if it does not exist, as device locking
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|            ;; is mandatory for LUKS2.
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|            (mkdir-p "/run/cryptsetup/")
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| 
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|            ;; Use 'cryptsetup-static', not 'cryptsetup', to avoid pulling the
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|            ;; whole world inside the initrd (for when we're in an initrd).
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|            ;; 'cryptsetup open' requires standard input to be a tty to allow
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|            ;; for interaction but shepherd sets standard input to /dev/null;
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|            ;; thus, explicitly request a tty.
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|            (let ((partition
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|                   ;; Note: We cannot use the "UUID=source" syntax here
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|                   ;; because 'cryptsetup' implements it by searching the
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|                   ;; udev-populated /dev/disk/by-id directory but udev may
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|                   ;; be unavailable at the time we run this.
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|                   (if (bytevector? source)
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|                       (or (let loop ((tries-left 10))
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|                             (and (positive? tries-left)
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|                                  (or (find-partition-by-luks-uuid source)
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|                                      ;; If the underlying partition is
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|                                      ;; not found, try again after
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|                                      ;; waiting a second, up to ten
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|                                      ;; times.  FIXME: This should be
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|                                      ;; dealt with in a more robust way.
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|                                      (begin (sleep 1)
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|                                             (loop (- tries-left 1))))))
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|                           (error "LUKS partition not found" source))
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|                       source)))
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|              ;; We want to fallback to the password unlock if the keyfile fails.
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|              (or (and keyfile
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|                       (zero? (system*/tty
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|                               #$(file-append cryptsetup-static "/sbin/cryptsetup")
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|                               "open" "--type" "luks"
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|                               "--key-file" keyfile
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|                               partition #$target)))
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|                  (zero? (system*/tty
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|                          #$(file-append cryptsetup-static "/sbin/cryptsetup")
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|                          "open" "--type" "luks"
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|                          partition #$target)))))))))
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| 
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| (define (close-luks-device source targets)
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|   "Return a gexp that closes TARGET, a LUKS device."
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|   (match targets
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|     ((target)
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|      #~(zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup")
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|                        "close" #$target)))))
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| 
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| (define* (check-luks-device md #:key
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|                             needed-for-boot?
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|                             (initrd-modules '())
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|                             #:allow-other-keys
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|                             #:rest rest)
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|   "Ensure the source of MD is valid."
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|   (let ((source   (mapped-device-source md))
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|         (location (mapped-device-location md)))
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|     (or (not (zero? (getuid)))
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|         (if (uuid? source)
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|             (match (find-partition-by-luks-uuid (uuid-bytevector source))
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|               (#f
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|                (raise (make-compound-condition
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|                        (formatted-message (G_ "no LUKS partition with UUID '~a'")
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|                                           (uuid->string source))
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|                        (condition
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|                         (&error-location
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|                          (location (source-properties->location
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|                                     (mapped-device-location md))))))))
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|               ((? string? device)
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|                (check-device-initrd-modules device initrd-modules location)))
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|             (check-device-initrd-modules source initrd-modules location)))))
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| 
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| (define luks-device-mapping
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|   ;; The type of LUKS mapped devices.
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|   (mapped-device-kind
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|    (open open-luks-device)
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|    (close close-luks-device)
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|    (check check-luks-device)
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|    (modules '((rnrs bytevectors)                  ;bytevector?
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|               ((gnu build file-systems)
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|                #:select (find-partition-by-luks-uuid system*/tty))))))
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| 
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| (define* (luks-device-mapping-with-options #:key key-file)
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|   "Return a luks-device-mapping object with open modified to pass the arguments
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| into the open-luks-device procedure."
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|   (mapped-device-kind
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|    (inherit luks-device-mapping)
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|    (open (λ (source targets) (open-luks-device source targets
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|                                                #:key-file key-file)))))
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| 
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| (define (open-raid-device sources targets)
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|   "Return a gexp that assembles SOURCES (a list of devices) to the RAID device
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| TARGET (e.g., \"/dev/md0\"), using 'mdadm'."
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|   (match targets
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|     ((target)
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|      #~(let ((sources '#$sources)
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| 
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|              ;; XXX: We're not at the top level here.  We could use a
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|              ;; non-top-level 'use-modules' form but that doesn't work when the
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|              ;; code is eval'd, like the Shepherd does.
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|              (every   (@ (srfi srfi-1) every))
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|              (format  (@ (ice-9 format) format)))
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|          (let loop ((attempts 0))
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|            (unless (every file-exists? sources)
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|              (when (> attempts 20)
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|                (error "RAID devices did not show up; bailing out"
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|                       sources))
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| 
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|              (format #t "waiting for RAID source devices~{ ~a~}...~%"
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|                      sources)
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|              (sleep 1)
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|              (loop (+ 1 attempts))))
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| 
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|          ;; Use 'mdadm-static' rather than 'mdadm' to avoid pulling its whole
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|          ;; closure (80 MiB) in the initrd when a RAID device is needed for boot.
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|          (zero? (apply system* #$(file-append mdadm-static "/sbin/mdadm")
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|                        "--assemble" #$target sources))))))
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| 
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| (define (close-raid-device sources targets)
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|   "Return a gexp that stops the RAID device TARGET."
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|   (match targets
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|     ((target)
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|      #~(zero? (system* #$(file-append mdadm-static "/sbin/mdadm")
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|                        "--stop" #$target)))))
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| 
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| (define raid-device-mapping
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|   ;; The type of RAID mapped devices.
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|   (mapped-device-kind
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|    (open open-raid-device)
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|    (close close-raid-device)))
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| 
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| (define (open-lvm-device source targets)
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|   #~(and
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|      (zero? (system* #$(file-append lvm2-static "/sbin/lvm")
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|                      "vgchange" "--activate" "ay" #$source))
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|      ; /dev/mapper nodes are usually created by udev, but udev may be unavailable at the time we run this. So we create them here.
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|      (zero? (system* #$(file-append lvm2-static "/sbin/lvm")
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|                      "vgscan" "--mknodes"))
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|      (every file-exists? (map (lambda (file) (string-append "/dev/mapper/" file))
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|                               '#$targets))))
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| 
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| 
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| (define (close-lvm-device source targets)
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|   #~(zero? (system* #$(file-append lvm2-static "/sbin/lvm")
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|                     "vgchange" "--activate" "n" #$source)))
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| 
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| (define lvm-device-mapping
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|   (mapped-device-kind
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|    (open open-lvm-device)
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|    (close close-lvm-device)
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|    (modules '((srfi srfi-1)))))
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| 
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| ;;; mapped-devices.scm ends here
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