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c5df1839 | 1 | ;;; GNU Guix --- Functional package management for GNU |
38434419 | 2 | ;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org> |
c5df1839 LC |
3 | ;;; |
4 | ;;; This file is part of GNU Guix. | |
5 | ;;; | |
6 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
7 | ;;; under the terms of the GNU General Public License as published by | |
8 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
9 | ;;; your option) any later version. | |
10 | ;;; | |
11 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
12 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | ;;; GNU General Public License for more details. | |
15 | ;;; | |
16 | ;;; You should have received a copy of the GNU General Public License | |
17 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
18 | ||
19 | (define-module (gnu system file-systems) | |
575b4b09 | 20 | #:use-module (ice-9 match) |
7597478e | 21 | #:use-module (srfi srfi-1) |
c5df1839 | 22 | #:use-module (guix records) |
9b336338 | 23 | #:use-module (gnu system uuid) |
47cef4ec LC |
24 | #:re-export (uuid ;backward compatibility |
25 | string->uuid | |
f8865db6 | 26 | uuid->string) |
c5df1839 LC |
27 | #:export (<file-system> |
28 | file-system | |
29 | file-system? | |
30 | file-system-device | |
d4c87617 | 31 | file-system-title |
c5df1839 LC |
32 | file-system-mount-point |
33 | file-system-type | |
34 | file-system-needed-for-boot? | |
35 | file-system-flags | |
36 | file-system-options | |
be21979d | 37 | file-system-mount? |
4e469051 LC |
38 | file-system-check? |
39 | file-system-create-mount-point? | |
e51710d1 | 40 | file-system-dependencies |
dd41a7f8 | 41 | file-system-location |
c5df1839 | 42 | |
278d486b LC |
43 | file-system-type-predicate |
44 | ||
575b4b09 | 45 | file-system->spec |
5970e8e2 | 46 | spec->file-system |
d77a0bd6 | 47 | specification->file-system-mapping |
575b4b09 | 48 | |
c5df1839 | 49 | %fuse-control-file-system |
a69576ea | 50 | %binary-format-file-system |
705f8b68 MW |
51 | %shared-memory-file-system |
52 | %pseudo-terminal-file-system | |
3c185b24 | 53 | %tty-gid |
3392ce5d | 54 | %immutable-store |
727636aa | 55 | %control-groups |
14454f0b | 56 | %elogind-file-systems |
a69576ea | 57 | |
5dae0186 | 58 | %base-file-systems |
c829bc80 | 59 | %container-file-systems |
5dae0186 | 60 | |
9110c2e9 DT |
61 | <file-system-mapping> |
62 | file-system-mapping | |
63 | file-system-mapping? | |
64 | file-system-mapping-source | |
65 | file-system-mapping-target | |
66 | file-system-mapping-writable? | |
67 | ||
d2a5e698 LC |
68 | file-system-mapping->bind-mount |
69 | ||
7597478e LC |
70 | %store-mapping |
71 | %network-configuration-files | |
72 | %network-file-mappings)) | |
c5df1839 LC |
73 | |
74 | ;;; Commentary: | |
75 | ;;; | |
76 | ;;; Declaring file systems to be mounted. | |
77 | ;;; | |
278d486b LC |
78 | ;;; Note: this file system is used both in the Shepherd and on the "host |
79 | ;;; side", so it must not include (gnu packages …) modules. | |
80 | ;;; | |
c5df1839 LC |
81 | ;;; Code: |
82 | ||
83 | ;; File system declaration. | |
84 | (define-record-type* <file-system> file-system | |
85 | make-file-system | |
86 | file-system? | |
87 | (device file-system-device) ; string | |
d4c87617 LC |
88 | (title file-system-title ; 'device | 'label | 'uuid |
89 | (default 'device)) | |
c5df1839 LC |
90 | (mount-point file-system-mount-point) ; string |
91 | (type file-system-type) ; string | |
92 | (flags file-system-flags ; list of symbols | |
93 | (default '())) | |
94 | (options file-system-options ; string or #f | |
95 | (default #f)) | |
be21979d LC |
96 | (mount? file-system-mount? ; Boolean |
97 | (default #t)) | |
4d6b879c | 98 | (needed-for-boot? %file-system-needed-for-boot? ; Boolean |
c5df1839 LC |
99 | (default #f)) |
100 | (check? file-system-check? ; Boolean | |
4e469051 LC |
101 | (default #t)) |
102 | (create-mount-point? file-system-create-mount-point? ; Boolean | |
e51710d1 | 103 | (default #f)) |
e502bf89 | 104 | (dependencies file-system-dependencies ; list of <file-system> |
dd41a7f8 LC |
105 | (default '())) ; or <mapped-device> |
106 | (location file-system-location | |
107 | (default (current-source-location)) | |
108 | (innate))) | |
c5df1839 | 109 | |
ad167d02 LC |
110 | ;; Note: This module is used both on the build side and on the host side. |
111 | ;; Arrange not to pull (guix store) and (guix config) because the latter | |
112 | ;; differs from user to user. | |
113 | (define (%store-prefix) | |
114 | "Return the store prefix." | |
115 | (cond ((resolve-module '(guix store) #:ensure #f) | |
116 | => | |
117 | (lambda (store) | |
118 | ((module-ref store '%store-prefix)))) | |
119 | ((getenv "NIX_STORE") | |
120 | => identity) | |
121 | (else | |
122 | "/gnu/store"))) | |
123 | ||
38434419 LC |
124 | (define %not-slash |
125 | (char-set-complement (char-set #\/))) | |
126 | ||
127 | (define (file-prefix? file1 file2) | |
128 | "Return #t if FILE1 denotes the name of a file that is a parent of FILE2, | |
129 | where both FILE1 and FILE2 are absolute file name. For example: | |
130 | ||
131 | (file-prefix? \"/gnu\" \"/gnu/store\") | |
132 | => #t | |
133 | ||
134 | (file-prefix? \"/gn\" \"/gnu/store\") | |
135 | => #f | |
136 | " | |
137 | (and (string-prefix? "/" file1) | |
138 | (string-prefix? "/" file2) | |
139 | (let loop ((file1 (string-tokenize file1 %not-slash)) | |
140 | (file2 (string-tokenize file2 %not-slash))) | |
141 | (match file1 | |
142 | (() | |
143 | #t) | |
144 | ((head1 tail1 ...) | |
145 | (match file2 | |
146 | ((head2 tail2 ...) | |
147 | (and (string=? head1 head2) (loop tail1 tail2))) | |
148 | (() | |
149 | #f))))))) | |
150 | ||
151 | (define (file-system-needed-for-boot? fs) | |
152 | "Return true if FS has the 'needed-for-boot?' flag set, or if it holds the | |
153 | store--e.g., if FS is the root file system." | |
4d6b879c | 154 | (or (%file-system-needed-for-boot? fs) |
38434419 LC |
155 | (and (file-prefix? (file-system-mount-point fs) (%store-prefix)) |
156 | (not (memq 'bind-mount (file-system-flags fs)))))) | |
4d6b879c | 157 | |
575b4b09 DT |
158 | (define (file-system->spec fs) |
159 | "Return a list corresponding to file-system FS that can be passed to the | |
160 | initrd code." | |
161 | (match fs | |
be21979d | 162 | (($ <file-system> device title mount-point type flags options _ _ check?) |
9b336338 LC |
163 | (list (if (uuid? device) |
164 | (uuid-bytevector device) | |
165 | device) | |
166 | title mount-point type flags options check?)))) | |
575b4b09 | 167 | |
5970e8e2 LC |
168 | (define (spec->file-system sexp) |
169 | "Deserialize SEXP, a list, to the corresponding <file-system> object." | |
170 | (match sexp | |
171 | ((device title mount-point type flags options check?) | |
172 | (file-system | |
173 | (device device) (title title) | |
174 | (mount-point mount-point) (type type) | |
175 | (flags flags) (options options) | |
176 | (check? check?))))) | |
177 | ||
d77a0bd6 LC |
178 | (define (specification->file-system-mapping spec writable?) |
179 | "Read the SPEC and return the corresponding <file-system-mapping>. SPEC is | |
180 | a string of the form \"SOURCE\" or \"SOURCE=TARGET\". The former specifies | |
181 | that SOURCE from the host should be mounted at SOURCE in the other system. | |
182 | The latter format specifies that SOURCE from the host should be mounted at | |
183 | TARGET in the other system." | |
184 | (let ((index (string-index spec #\=))) | |
185 | (if index | |
186 | (file-system-mapping | |
187 | (source (substring spec 0 index)) | |
188 | (target (substring spec (+ 1 index))) | |
189 | (writable? writable?)) | |
190 | (file-system-mapping | |
191 | (source spec) | |
192 | (target spec) | |
193 | (writable? writable?))))) | |
194 | ||
661a1d79 LC |
195 | \f |
196 | ;;; | |
197 | ;;; Common file systems. | |
198 | ;;; | |
199 | ||
c5df1839 LC |
200 | (define %fuse-control-file-system |
201 | ;; Control file system for Linux' file systems in user-space (FUSE). | |
202 | (file-system | |
203 | (device "fusectl") | |
204 | (mount-point "/sys/fs/fuse/connections") | |
205 | (type "fusectl") | |
206 | (check? #f))) | |
207 | ||
208 | (define %binary-format-file-system | |
209 | ;; Support for arbitrary executable binary format. | |
210 | (file-system | |
211 | (device "binfmt_misc") | |
212 | (mount-point "/proc/sys/fs/binfmt_misc") | |
213 | (type "binfmt_misc") | |
214 | (check? #f))) | |
215 | ||
7f239fd3 LC |
216 | (define %tty-gid |
217 | ;; ID of the 'tty' group. Allocate it statically to make it easy to refer | |
218 | ;; to it from here and from the 'tty' group definitions. | |
c8fa3426 | 219 | 996) |
7f239fd3 LC |
220 | |
221 | (define %pseudo-terminal-file-system | |
222 | ;; The pseudo-terminal file system. It needs to be mounted so that | |
223 | ;; statfs(2) returns DEVPTS_SUPER_MAGIC like libc's getpt(3) expects (and | |
224 | ;; thus openpty(3) and its users, such as xterm.) | |
225 | (file-system | |
226 | (device "none") | |
227 | (mount-point "/dev/pts") | |
228 | (type "devpts") | |
229 | (check? #f) | |
230 | (needed-for-boot? #f) | |
231 | (create-mount-point? #t) | |
232 | (options (string-append "gid=" (number->string %tty-gid) ",mode=620")))) | |
a69576ea | 233 | |
db17ae5c LC |
234 | (define %shared-memory-file-system |
235 | ;; Shared memory. | |
236 | (file-system | |
237 | (device "tmpfs") | |
238 | (mount-point "/dev/shm") | |
239 | (type "tmpfs") | |
240 | (check? #f) | |
241 | (flags '(no-suid no-dev)) | |
242 | (options "size=50%") ;TODO: make size configurable | |
243 | (create-mount-point? #t))) | |
244 | ||
3392ce5d LC |
245 | (define %immutable-store |
246 | ;; Read-only store to avoid users or daemons accidentally modifying it. | |
247 | ;; 'guix-daemon' has provisions to remount it read-write in its own name | |
248 | ;; space. | |
249 | (file-system | |
250 | (device (%store-prefix)) | |
251 | (mount-point (%store-prefix)) | |
252 | (type "none") | |
253 | (check? #f) | |
254 | (flags '(read-only bind-mount)))) | |
255 | ||
727636aa | 256 | (define %control-groups |
b78cad85 LC |
257 | (let ((parent (file-system |
258 | (device "cgroup") | |
259 | (mount-point "/sys/fs/cgroup") | |
260 | (type "tmpfs") | |
261 | (check? #f)))) | |
262 | (cons parent | |
263 | (map (lambda (subsystem) | |
264 | (file-system | |
265 | (device "cgroup") | |
266 | (mount-point (string-append "/sys/fs/cgroup/" subsystem)) | |
267 | (type "cgroup") | |
268 | (check? #f) | |
269 | (options subsystem) | |
270 | (create-mount-point? #t) | |
271 | ||
272 | ;; This must be mounted after, and unmounted before the | |
273 | ;; parent directory. | |
274 | (dependencies (list parent)))) | |
275 | '("cpuset" "cpu" "cpuacct" "memory" "devices" "freezer" | |
276 | "blkio" "perf_event" "hugetlb"))))) | |
727636aa | 277 | |
14454f0b MW |
278 | (define %elogind-file-systems |
279 | ;; We don't use systemd, but these file systems are needed for elogind, | |
280 | ;; which was extracted from systemd. | |
281 | (list (file-system | |
282 | (device "none") | |
283 | (mount-point "/run/systemd") | |
284 | (type "tmpfs") | |
285 | (check? #f) | |
286 | (flags '(no-suid no-dev no-exec)) | |
287 | (options "mode=0755") | |
288 | (create-mount-point? #t)) | |
289 | (file-system | |
290 | (device "none") | |
291 | (mount-point "/run/user") | |
292 | (type "tmpfs") | |
293 | (check? #f) | |
294 | (flags '(no-suid no-dev no-exec)) | |
295 | (options "mode=0755") | |
a7e50a2a AW |
296 | (create-mount-point? #t)) |
297 | ;; Elogind uses cgroups to organize processes, allowing it to map PIDs | |
298 | ;; to sessions. Elogind's cgroup hierarchy isn't associated with any | |
299 | ;; resource controller ("subsystem"). | |
300 | (file-system | |
301 | (device "cgroup") | |
302 | (mount-point "/sys/fs/cgroup/elogind") | |
303 | (type "cgroup") | |
304 | (check? #f) | |
305 | (options "none,name=elogind") | |
306 | (create-mount-point? #t) | |
307 | (dependencies (list (car %control-groups)))))) | |
14454f0b | 308 | |
a69576ea LC |
309 | (define %base-file-systems |
310 | ;; List of basic file systems to be mounted. Note that /proc and /sys are | |
311 | ;; currently mounted by the initrd. | |
cc0e575a | 312 | (append (list %pseudo-terminal-file-system |
727636aa DT |
313 | %shared-memory-file-system |
314 | %immutable-store) | |
315 | %control-groups)) | |
a69576ea | 316 | |
c829bc80 DT |
317 | ;; File systems for Linux containers differ from %base-file-systems in that |
318 | ;; they impose additional restrictions such as no-exec or need different | |
319 | ;; options to function properly. | |
320 | ;; | |
321 | ;; The file system flags and options conform to the libcontainer | |
322 | ;; specification: | |
323 | ;; https://github.com/docker/libcontainer/blob/master/SPEC.md#filesystem | |
324 | (define %container-file-systems | |
325 | (list | |
b57ec5f6 | 326 | ;; Pseudo-terminal file system. |
c829bc80 DT |
327 | (file-system |
328 | (device "none") | |
329 | (mount-point "/dev/pts") | |
330 | (type "devpts") | |
331 | (flags '(no-exec no-suid)) | |
332 | (needed-for-boot? #t) | |
333 | (create-mount-point? #t) | |
334 | (check? #f) | |
335 | (options "newinstance,ptmxmode=0666,mode=620")) | |
336 | ;; Shared memory file system. | |
337 | (file-system | |
338 | (device "tmpfs") | |
339 | (mount-point "/dev/shm") | |
340 | (type "tmpfs") | |
341 | (flags '(no-exec no-suid no-dev)) | |
342 | (options "mode=1777,size=65536k") | |
343 | (needed-for-boot? #t) | |
344 | (create-mount-point? #t) | |
345 | (check? #f)) | |
346 | ;; Message queue file system. | |
347 | (file-system | |
348 | (device "mqueue") | |
349 | (mount-point "/dev/mqueue") | |
350 | (type "mqueue") | |
351 | (flags '(no-exec no-suid no-dev)) | |
352 | (needed-for-boot? #t) | |
353 | (create-mount-point? #t) | |
354 | (check? #f)))) | |
355 | ||
9110c2e9 DT |
356 | \f |
357 | ;;; | |
358 | ;;; Shared file systems, for VMs/containers. | |
359 | ;;; | |
360 | ||
361 | ;; Mapping of host file system SOURCE to mount point TARGET in the guest. | |
362 | (define-record-type* <file-system-mapping> file-system-mapping | |
363 | make-file-system-mapping | |
364 | file-system-mapping? | |
365 | (source file-system-mapping-source) ;string | |
366 | (target file-system-mapping-target) ;string | |
367 | (writable? file-system-mapping-writable? ;Boolean | |
368 | (default #f))) | |
369 | ||
d2a5e698 LC |
370 | (define (file-system-mapping->bind-mount mapping) |
371 | "Return a file system that realizes MAPPING, a <file-system-mapping>, using | |
372 | a bind mount." | |
373 | (match mapping | |
374 | (($ <file-system-mapping> source target writable?) | |
375 | (file-system | |
376 | (mount-point target) | |
377 | (device source) | |
378 | (type "none") | |
379 | (flags (if writable? | |
380 | '(bind-mount) | |
381 | '(bind-mount read-only))) | |
382 | (check? #f) | |
383 | (create-mount-point? #t))))) | |
384 | ||
9110c2e9 DT |
385 | (define %store-mapping |
386 | ;; Mapping of the host's store into the guest. | |
387 | (file-system-mapping | |
388 | (source (%store-prefix)) | |
389 | (target (%store-prefix)) | |
390 | (writable? #f))) | |
391 | ||
7597478e LC |
392 | (define %network-configuration-files |
393 | ;; List of essential network configuration files. | |
394 | '("/etc/resolv.conf" | |
395 | "/etc/nsswitch.conf" | |
396 | "/etc/services" | |
397 | "/etc/hosts")) | |
398 | ||
399 | (define %network-file-mappings | |
400 | ;; List of file mappings for essential network files. | |
401 | (filter-map (lambda (file) | |
402 | (file-system-mapping | |
403 | (source file) | |
404 | (target file) | |
405 | ;; XXX: On some GNU/Linux systems, /etc/resolv.conf is a | |
406 | ;; symlink to a file in a tmpfs which, for an unknown reason, | |
407 | ;; cannot be bind mounted read-only within the container. | |
408 | (writable? (string=? file "/etc/resolv.conf")))) | |
409 | %network-configuration-files)) | |
410 | ||
72089954 | 411 | (define (file-system-type-predicate type) |
7dbd75b3 LC |
412 | "Return a predicate that, when passed a file system, returns #t if that file |
413 | system has the given TYPE." | |
72089954 DM |
414 | (lambda (fs) |
415 | (string=? (file-system-type fs) type))) | |
416 | ||
c5df1839 | 417 | ;;; file-systems.scm ends here |