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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> |
060d62a7 LC |
4 | ;;; |
5 | ;;; This file is part of GNU Guix. | |
6 | ;;; | |
7 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
8 | ;;; under the terms of the GNU General Public License as published by | |
9 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
10 | ;;; your option) any later version. | |
11 | ;;; | |
12 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
13 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | ;;; GNU General Public License for more details. | |
16 | ;;; | |
17 | ;;; You should have received a copy of the GNU General Public License | |
18 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
19 | ||
20 | (define-module (gnu system mapped-devices) | |
374f14c2 | 21 | #:use-module (guix gexp) |
060d62a7 | 22 | #:use-module (guix records) |
239c6e27 | 23 | #:use-module (guix modules) |
1ea507bc LC |
24 | #:use-module (gnu services) |
25 | #:use-module (gnu services shepherd) | |
374f14c2 | 26 | #:autoload (gnu packages cryptsetup) (cryptsetup) |
97c8aef1 | 27 | #:autoload (gnu packages linux) (mdadm) |
ffba7d49 | 28 | #:use-module (srfi srfi-1) |
1ea507bc | 29 | #:use-module (ice-9 match) |
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30 | #:export (mapped-device |
31 | mapped-device? | |
32 | mapped-device-source | |
33 | mapped-device-target | |
34 | mapped-device-type | |
35 | ||
36 | mapped-device-kind | |
37 | mapped-device-kind? | |
38 | mapped-device-kind-open | |
374f14c2 LC |
39 | mapped-device-kind-close |
40 | ||
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41 | device-mapping-service-type |
42 | device-mapping-service | |
43 | ||
97c8aef1 AE |
44 | luks-device-mapping |
45 | raid-device-mapping)) | |
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46 | |
47 | ;;; Commentary: | |
48 | ;;; | |
49 | ;;; This module supports "device mapping", a concept implemented by Linux's | |
50 | ;;; device-mapper. | |
51 | ;;; | |
52 | ;;; Code: | |
53 | ||
54 | (define-record-type* <mapped-device> mapped-device | |
55 | make-mapped-device | |
56 | mapped-device? | |
57 | (source mapped-device-source) ;string | |
58 | (target mapped-device-target) ;string | |
59 | (type mapped-device-type)) ;<mapped-device-kind> | |
60 | ||
61 | (define-record-type* <mapped-device-type> mapped-device-kind | |
62 | make-mapped-device-kind | |
63 | mapped-device-kind? | |
64 | (open mapped-device-kind-open) ;source target -> gexp | |
65 | (close mapped-device-kind-close ;source target -> gexp | |
66 | (default (const #~(const #f))))) | |
67 | ||
374f14c2 | 68 | \f |
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69 | ;;; |
70 | ;;; Device mapping as a Shepherd service. | |
71 | ;;; | |
72 | ||
73 | (define device-mapping-service-type | |
74 | (shepherd-service-type | |
75 | 'device-mapping | |
76 | (match-lambda | |
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77 | (($ <mapped-device> source target |
78 | ($ <mapped-device-type> open close)) | |
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79 | (shepherd-service |
80 | (provision (list (symbol-append 'device-mapping- (string->symbol target)))) | |
81 | (requirement '(udev)) | |
82 | (documentation "Map a device node using Linux's device mapper.") | |
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83 | (start #~(lambda () #$(open source target))) |
84 | (stop #~(lambda _ (not #$(close source target)))) | |
dfe06f6e | 85 | (respawn? #f)))))) |
1ea507bc | 86 | |
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87 | (define (device-mapping-service mapped-device) |
88 | "Return a service that sets up @var{mapped-device}." | |
89 | (service device-mapping-service-type mapped-device)) | |
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90 | |
91 | \f | |
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92 | ;;; |
93 | ;;; Common device mappings. | |
94 | ;;; | |
95 | ||
96 | (define (open-luks-device source target) | |
97 | "Return a gexp that maps SOURCE to TARGET as a LUKS device, using | |
98 | 'cryptsetup'." | |
239c6e27 LC |
99 | (with-imported-modules (source-module-closure |
100 | '((gnu build file-systems))) | |
a91c3fc7 | 101 | #~(let ((source #$source)) |
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102 | ;; XXX: 'use-modules' should be at the top level. |
103 | (use-modules (rnrs bytevectors) ;bytevector? | |
104 | ((gnu build file-systems) | |
105 | #:select (find-partition-by-luks-uuid))) | |
106 | ||
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107 | (zero? (system* (string-append #$cryptsetup "/sbin/cryptsetup") |
108 | "open" "--type" "luks" | |
109 | ||
110 | ;; Note: We cannot use the "UUID=source" syntax here | |
111 | ;; because 'cryptsetup' implements it by searching the | |
112 | ;; udev-populated /dev/disk/by-id directory but udev may | |
113 | ;; be unavailable at the time we run this. | |
114 | (if (bytevector? source) | |
115 | (or (find-partition-by-luks-uuid source) | |
116 | (error "LUKS partition not found" source)) | |
117 | source) | |
118 | ||
119 | #$target))))) | |
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120 | |
121 | (define (close-luks-device source target) | |
122 | "Return a gexp that closes TARGET, a LUKS device." | |
123 | #~(zero? (system* (string-append #$cryptsetup "/sbin/cryptsetup") | |
124 | "close" #$target))) | |
125 | ||
126 | (define luks-device-mapping | |
127 | ;; The type of LUKS mapped devices. | |
128 | (mapped-device-kind | |
129 | (open open-luks-device) | |
130 | (close close-luks-device))) | |
131 | ||
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132 | (define (open-raid-device sources target) |
133 | "Return a gexp that assembles SOURCES (a list of devices) to the RAID device | |
134 | TARGET (e.g., \"/dev/md0\"), using 'mdadm'." | |
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135 | #~(let ((sources '#$sources) |
136 | ||
137 | ;; XXX: We're not at the top level here. We could use a | |
138 | ;; non-top-level 'use-modules' form but that doesn't work when the | |
139 | ;; code is eval'd, like the Shepherd does. | |
140 | (every (@ (srfi srfi-1) every)) | |
141 | (format (@ (ice-9 format) format))) | |
142 | (let loop ((attempts 0)) | |
143 | (unless (every file-exists? sources) | |
144 | (when (> attempts 20) | |
145 | (error "RAID devices did not show up; bailing out" | |
146 | sources)) | |
147 | ||
148 | (format #t "waiting for RAID source devices~{ ~a~}...~%" | |
149 | sources) | |
150 | (sleep 1) | |
151 | (loop (+ 1 attempts)))) | |
152 | ||
153 | (zero? (system* (string-append #$mdadm "/sbin/mdadm") | |
154 | "--assemble" #$target sources)))) | |
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155 | |
156 | (define (close-raid-device sources target) | |
97c8aef1 AE |
157 | "Return a gexp that stops the RAID device TARGET." |
158 | #~(zero? (system* (string-append #$mdadm "/sbin/mdadm") | |
159 | "--stop" #$target))) | |
160 | ||
161 | (define raid-device-mapping | |
162 | ;; The type of RAID mapped devices. | |
163 | (mapped-device-kind | |
164 | (open open-raid-device) | |
165 | (close close-raid-device))) | |
166 | ||
060d62a7 | 167 | ;;; mapped-devices.scm ends here |