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1 | ;;; GNU Guix --- Functional package management for GNU |
2 | ;;; Copyright © 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org> | |
97c8aef1 | 3 | ;;; Copyright © 2016 Andreas Enge <andreas@enge.fr> |
f45878a8 | 4 | ;;; Copyright © 2017 Mark H Weaver <mhw@netris.org> |
060d62a7 LC |
5 | ;;; |
6 | ;;; This file is part of GNU Guix. | |
7 | ;;; | |
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. | |
12 | ;;; | |
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. | |
17 | ;;; | |
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/>. | |
20 | ||
21 | (define-module (gnu system mapped-devices) | |
374f14c2 | 22 | #:use-module (guix gexp) |
060d62a7 | 23 | #:use-module (guix records) |
239c6e27 | 24 | #:use-module (guix modules) |
1ea507bc LC |
25 | #:use-module (gnu services) |
26 | #:use-module (gnu services shepherd) | |
b7d408ec | 27 | #:autoload (gnu packages cryptsetup) (cryptsetup-static) |
4ed2f515 | 28 | #:autoload (gnu packages linux) (mdadm-static) |
ffba7d49 | 29 | #:use-module (srfi srfi-1) |
1ea507bc | 30 | #:use-module (ice-9 match) |
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31 | #:export (mapped-device |
32 | mapped-device? | |
33 | mapped-device-source | |
34 | mapped-device-target | |
35 | mapped-device-type | |
36 | ||
37 | mapped-device-kind | |
38 | mapped-device-kind? | |
39 | mapped-device-kind-open | |
374f14c2 LC |
40 | mapped-device-kind-close |
41 | ||
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42 | device-mapping-service-type |
43 | device-mapping-service | |
44 | ||
97c8aef1 AE |
45 | luks-device-mapping |
46 | raid-device-mapping)) | |
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47 | |
48 | ;;; Commentary: | |
49 | ;;; | |
50 | ;;; This module supports "device mapping", a concept implemented by Linux's | |
51 | ;;; device-mapper. | |
52 | ;;; | |
53 | ;;; Code: | |
54 | ||
55 | (define-record-type* <mapped-device> mapped-device | |
56 | make-mapped-device | |
57 | mapped-device? | |
d6d1cea6 | 58 | (source mapped-device-source) ;string | list of strings |
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59 | (target mapped-device-target) ;string |
60 | (type mapped-device-type)) ;<mapped-device-kind> | |
61 | ||
62 | (define-record-type* <mapped-device-type> mapped-device-kind | |
63 | make-mapped-device-kind | |
64 | mapped-device-kind? | |
65 | (open mapped-device-kind-open) ;source target -> gexp | |
66 | (close mapped-device-kind-close ;source target -> gexp | |
67 | (default (const #~(const #f))))) | |
68 | ||
374f14c2 | 69 | \f |
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70 | ;;; |
71 | ;;; Device mapping as a Shepherd service. | |
72 | ;;; | |
73 | ||
74 | (define device-mapping-service-type | |
75 | (shepherd-service-type | |
76 | 'device-mapping | |
77 | (match-lambda | |
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78 | (($ <mapped-device> source target |
79 | ($ <mapped-device-type> open close)) | |
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80 | (shepherd-service |
81 | (provision (list (symbol-append 'device-mapping- (string->symbol target)))) | |
82 | (requirement '(udev)) | |
83 | (documentation "Map a device node using Linux's device mapper.") | |
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84 | (start #~(lambda () #$(open source target))) |
85 | (stop #~(lambda _ (not #$(close source target)))) | |
dfe06f6e | 86 | (respawn? #f)))))) |
1ea507bc | 87 | |
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88 | (define (device-mapping-service mapped-device) |
89 | "Return a service that sets up @var{mapped-device}." | |
90 | (service device-mapping-service-type mapped-device)) | |
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91 | |
92 | \f | |
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93 | ;;; |
94 | ;;; Common device mappings. | |
95 | ;;; | |
96 | ||
97 | (define (open-luks-device source target) | |
98 | "Return a gexp that maps SOURCE to TARGET as a LUKS device, using | |
99 | 'cryptsetup'." | |
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100 | (with-imported-modules (source-module-closure |
101 | '((gnu build file-systems))) | |
a91c3fc7 | 102 | #~(let ((source #$source)) |
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103 | ;; XXX: 'use-modules' should be at the top level. |
104 | (use-modules (rnrs bytevectors) ;bytevector? | |
105 | ((gnu build file-systems) | |
106 | #:select (find-partition-by-luks-uuid))) | |
107 | ||
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108 | ;; Use 'cryptsetup-static', not 'cryptsetup', to avoid pulling the |
109 | ;; whole world inside the initrd (for when we're in an initrd). | |
110 | (zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup") | |
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111 | "open" "--type" "luks" |
112 | ||
113 | ;; Note: We cannot use the "UUID=source" syntax here | |
114 | ;; because 'cryptsetup' implements it by searching the | |
115 | ;; udev-populated /dev/disk/by-id directory but udev may | |
116 | ;; be unavailable at the time we run this. | |
117 | (if (bytevector? source) | |
f45878a8 MW |
118 | (or (let loop ((tries-left 10)) |
119 | (and (positive? tries-left) | |
120 | (or (find-partition-by-luks-uuid source) | |
121 | ;; If the underlying partition is | |
122 | ;; not found, try again after | |
123 | ;; waiting a second, up to ten | |
124 | ;; times. FIXME: This should be | |
125 | ;; dealt with in a more robust way. | |
126 | (begin (sleep 1) | |
127 | (loop (- tries-left 1)))))) | |
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128 | (error "LUKS partition not found" source)) |
129 | source) | |
130 | ||
131 | #$target))))) | |
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132 | |
133 | (define (close-luks-device source target) | |
134 | "Return a gexp that closes TARGET, a LUKS device." | |
b7d408ec | 135 | #~(zero? (system* #$(file-append cryptsetup-static "/sbin/cryptsetup") |
374f14c2 LC |
136 | "close" #$target))) |
137 | ||
138 | (define luks-device-mapping | |
139 | ;; The type of LUKS mapped devices. | |
140 | (mapped-device-kind | |
141 | (open open-luks-device) | |
142 | (close close-luks-device))) | |
143 | ||
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144 | (define (open-raid-device sources target) |
145 | "Return a gexp that assembles SOURCES (a list of devices) to the RAID device | |
146 | TARGET (e.g., \"/dev/md0\"), using 'mdadm'." | |
10618627 LC |
147 | #~(let ((sources '#$sources) |
148 | ||
149 | ;; XXX: We're not at the top level here. We could use a | |
150 | ;; non-top-level 'use-modules' form but that doesn't work when the | |
151 | ;; code is eval'd, like the Shepherd does. | |
152 | (every (@ (srfi srfi-1) every)) | |
153 | (format (@ (ice-9 format) format))) | |
154 | (let loop ((attempts 0)) | |
155 | (unless (every file-exists? sources) | |
156 | (when (> attempts 20) | |
157 | (error "RAID devices did not show up; bailing out" | |
158 | sources)) | |
159 | ||
160 | (format #t "waiting for RAID source devices~{ ~a~}...~%" | |
161 | sources) | |
162 | (sleep 1) | |
163 | (loop (+ 1 attempts)))) | |
164 | ||
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165 | ;; Use 'mdadm-static' rather than 'mdadm' to avoid pulling its whole |
166 | ;; closure (80 MiB) in the initrd when a RAID device is needed for boot. | |
167 | (zero? (apply system* #$(file-append mdadm-static "/sbin/mdadm") | |
6e52376d | 168 | "--assemble" #$target sources)))) |
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169 | |
170 | (define (close-raid-device sources target) | |
97c8aef1 | 171 | "Return a gexp that stops the RAID device TARGET." |
4ed2f515 | 172 | #~(zero? (system* #$(file-append mdadm-static "/sbin/mdadm") |
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173 | "--stop" #$target))) |
174 | ||
175 | (define raid-device-mapping | |
176 | ;; The type of RAID mapped devices. | |
177 | (mapped-device-kind | |
178 | (open open-raid-device) | |
179 | (close close-raid-device))) | |
180 | ||
060d62a7 | 181 | ;;; mapped-devices.scm ends here |