1 ;;; GNU Guix --- Functional package management for GNU
2 ;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
3 ;;; Copyright © 2016 Andreas Enge <andreas@enge.fr>
4 ;;; Copyright © 2017, 2018 Mark H Weaver <mhw@netris.org>
6 ;;; This file is part of GNU Guix.
8 ;;; GNU Guix is free software; you can redistribute it and/or modify it
9 ;;; under the terms of the GNU General Public License as published by
10 ;;; the Free Software Foundation; either version 3 of the License, or (at
11 ;;; your option) any later version.
13 ;;; GNU Guix is distributed in the hope that it will be useful, but
14 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
15 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 ;;; GNU General Public License for more details.
18 ;;; You should have received a copy of the GNU General Public License
19 ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
21 (define-module (gnu system mapped-devices)
22 #:use-module (guix gexp)
23 #:use-module (guix records)
24 #:use-module ((guix modules) #:hide (file-name->module-name))
25 #:use-module (guix i18n)
26 #:use-module ((guix utils)
27 #:select (source-properties->location
30 #:use-module (gnu services)
31 #:use-module (gnu services shepherd)
32 #:use-module (gnu system uuid)
33 #:autoload (gnu build file-systems) (find-partition-by-luks-uuid)
34 #:autoload (gnu build linux-modules)
35 (device-module-aliases matching-modules known-module-aliases
36 normalize-module-name file-name->module-name)
37 #:autoload (gnu packages cryptsetup) (cryptsetup-static)
38 #:autoload (gnu packages linux) (mdadm-static)
39 #:use-module (srfi srfi-1)
40 #:use-module (srfi srfi-26)
41 #:use-module (srfi srfi-34)
42 #:use-module (srfi srfi-35)
43 #:use-module (ice-9 match)
44 #:export (mapped-device
49 mapped-device-location
53 mapped-device-kind-open
54 mapped-device-kind-close
55 mapped-device-kind-check
57 device-mapping-service-type
58 device-mapping-service
60 check-device-initrd-modules ;XXX: needs a better place
67 ;;; This module supports "device mapping", a concept implemented by Linux's
72 (define-record-type* <mapped-device> mapped-device
75 (source mapped-device-source) ;string | list of strings
76 (target mapped-device-target) ;string
77 (type mapped-device-type) ;<mapped-device-kind>
78 (location mapped-device-location
79 (default (current-source-location)) (innate)))
81 (define-record-type* <mapped-device-type> mapped-device-kind
82 make-mapped-device-kind
84 (open mapped-device-kind-open) ;source target -> gexp
85 (close mapped-device-kind-close ;source target -> gexp
86 (default (const #~(const #f))))
87 (check mapped-device-kind-check ;source -> Boolean
88 (default (const #t))))
92 ;;; Device mapping as a Shepherd service.
95 (define device-mapping-service-type
96 (shepherd-service-type
99 (($ <mapped-device> source target
100 ($ <mapped-device-type> open close))
102 (provision (list (symbol-append 'device-mapping- (string->symbol target))))
103 (requirement '(udev))
104 (documentation "Map a device node using Linux's device mapper.")
105 (start #~(lambda () #$(open source target)))
106 (stop #~(lambda _ (not #$(close source target))))
109 (define (device-mapping-service mapped-device)
110 "Return a service that sets up @var{mapped-device}."
111 (service device-mapping-service-type mapped-device))
118 (define (check-device-initrd-modules device linux-modules location)
119 "Raise an error if DEVICE needs modules beyond LINUX-MODULES to operate.
120 DEVICE must be a \"/dev\" file name."
122 ;; Attempt to load 'modules.alias' from the current kernel, assuming we're
123 ;; on GuixSD, and assuming that corresponds to the kernel we'll be
124 ;; installing. Skip the whole thing if that file cannot be read.
127 (known-module-aliases))
131 (let* ((modules (delete-duplicates
132 (append-map (cut matching-modules <> aliases)
133 (device-module-aliases device))))
135 ;; Module names (not file names) are supposed to use underscores
136 ;; instead of hyphens. MODULES is a list of module names, whereas
137 ;; LINUX-MODULES is file names without '.ko', so normalize them.
138 (provided (map file-name->module-name linux-modules))
139 (missing (remove (cut member <> provided) modules)))
140 (unless (null? missing)
141 ;; Note: What we suggest here is a list of module names (e.g.,
142 ;; "usb_storage"), not file names (e.g., "usb-storage.ko"). This is
143 ;; OK because we have machinery that accepts both the hyphen and the
144 ;; underscore version.
147 (message (format #f (G_ "you may need these modules \
148 in the initrd for ~a:~{ ~a~}")
151 (hint (format #f (G_ "Try adding them to the
152 @code{initrd-modules} field of your @code{operating-system} declaration, along
158 (initrd-modules (append (list~{ ~s~})
159 %base-initrd-modules)))
162 If you think this diagnostic is inaccurate, use the @option{--skip-checks}
163 option of @command{guix system}.\n")
166 (location (source-properties->location location)))))))))
170 ;;; Common device mappings.
173 (define (open-luks-device source target)
174 "Return a gexp that maps SOURCE to TARGET as a LUKS device, using
176 (with-imported-modules (source-module-closure
177 '((gnu build file-systems)))
178 #~(let ((source #$(if (uuid? source)
179 (uuid-bytevector source)
181 ;; XXX: 'use-modules' should be at the top level.
182 (use-modules (rnrs bytevectors) ;bytevector?
183 ((gnu build file-systems)
184 #:select (find-partition-by-luks-uuid)))
186 ;; Use 'cryptsetup-static', not 'cryptsetup', to avoid pulling the
187 ;; whole world inside the initrd (for when we're in an initrd).
188 (zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup")
189 "open" "--type" "luks"
191 ;; Note: We cannot use the "UUID=source" syntax here
192 ;; because 'cryptsetup' implements it by searching the
193 ;; udev-populated /dev/disk/by-id directory but udev may
194 ;; be unavailable at the time we run this.
195 (if (bytevector? source)
196 (or (let loop ((tries-left 10))
197 (and (positive? tries-left)
198 (or (find-partition-by-luks-uuid source)
199 ;; If the underlying partition is
200 ;; not found, try again after
201 ;; waiting a second, up to ten
202 ;; times. FIXME: This should be
203 ;; dealt with in a more robust way.
205 (loop (- tries-left 1))))))
206 (error "LUKS partition not found" source))
211 (define (close-luks-device source target)
212 "Return a gexp that closes TARGET, a LUKS device."
213 #~(zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup")
216 (define* (check-luks-device md #:key
221 "Ensure the source of MD is valid."
222 (let ((source (mapped-device-source md))
223 (location (mapped-device-location md)))
224 (or (not (zero? (getuid)))
226 (match (find-partition-by-luks-uuid (uuid-bytevector source))
230 (message (format #f (G_ "no LUKS partition with UUID '~a'")
231 (uuid->string source))))
233 (location (source-properties->location
234 (mapped-device-location md)))))))
236 (check-device-initrd-modules device initrd-modules location)))
237 (check-device-initrd-modules source initrd-modules location)))))
239 (define luks-device-mapping
240 ;; The type of LUKS mapped devices.
242 (open open-luks-device)
243 (close close-luks-device)
244 (check check-luks-device)))
246 (define (open-raid-device sources target)
247 "Return a gexp that assembles SOURCES (a list of devices) to the RAID device
248 TARGET (e.g., \"/dev/md0\"), using 'mdadm'."
249 #~(let ((sources '#$sources)
251 ;; XXX: We're not at the top level here. We could use a
252 ;; non-top-level 'use-modules' form but that doesn't work when the
253 ;; code is eval'd, like the Shepherd does.
254 (every (@ (srfi srfi-1) every))
255 (format (@ (ice-9 format) format)))
256 (let loop ((attempts 0))
257 (unless (every file-exists? sources)
258 (when (> attempts 20)
259 (error "RAID devices did not show up; bailing out"
262 (format #t "waiting for RAID source devices~{ ~a~}...~%"
265 (loop (+ 1 attempts))))
267 ;; Use 'mdadm-static' rather than 'mdadm' to avoid pulling its whole
268 ;; closure (80 MiB) in the initrd when a RAID device is needed for boot.
269 (zero? (apply system* #$(file-append mdadm-static "/sbin/mdadm")
270 "--assemble" #$target sources))))
272 (define (close-raid-device sources target)
273 "Return a gexp that stops the RAID device TARGET."
274 #~(zero? (system* #$(file-append mdadm-static "/sbin/mdadm")
277 (define raid-device-mapping
278 ;; The type of RAID mapped devices.
280 (open open-raid-device)
281 (close close-raid-device)))
283 ;;; mapped-devices.scm ends here