diff options
| -rw-r--r-- | Makefile.am | 1 | ||||
| -rw-r--r-- | doc/guix.texi | 18 | ||||
| -rw-r--r-- | gnu/system/file-systems.scm | 57 | ||||
| -rw-r--r-- | tests/file-systems.scm | 46 |
4 files changed, 121 insertions, 1 deletions
diff --git a/Makefile.am b/Makefile.am index 7059a8f594..5cf9314014 100644 --- a/Makefile.am +++ b/Makefile.am @@ -203,6 +203,7 @@ SCM_TESTS = \ tests/lint.scm \ tests/publish.scm \ tests/size.scm \ + tests/file-systems.scm \ tests/containers.scm if HAVE_GUILE_JSON diff --git a/doc/guix.texi b/doc/guix.texi index 7b1d18a151..ad5b38af31 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -4963,8 +4963,24 @@ interpreted as a file name; when it is @code{label}, then @code{device} is interpreted as a partition label name; when it is @code{uuid}, @code{device} is interpreted as a partition unique identifier (UUID). +UUIDs may be converted from their string representation (as shown by the +@command{tune2fs -l} command) using the @code{uuid} form, like this: + +@example +(file-system + (mount-point "/home") + (type "ext4") + (title 'uuid) + (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))) +@end example + The @code{label} and @code{uuid} options offer a way to refer to disk -partitions without having to hard-code their actual device name. +partitions without having to hard-code their actual device +name@footnote{Note that, while it is tempting to use +@file{/dev/disk/by-uuid} and similar device names to achieve the same +result, this is not recommended: These special device nodes are created +by the udev daemon and may be unavailable at the time the device is +mounted.}. However, when a file system's source is a mapped device (@pxref{Mapped Devices}), its @code{device} field @emph{must} refer to the mapped diff --git a/gnu/system/file-systems.scm b/gnu/system/file-systems.scm index 33926444b6..ece8fb41e6 100644 --- a/gnu/system/file-systems.scm +++ b/gnu/system/file-systems.scm @@ -18,9 +18,13 @@ (define-module (gnu system file-systems) #:use-module (ice-9 match) + #:use-module (ice-9 regex) #:use-module (guix gexp) #:use-module (guix records) #:use-module (guix store) + #:use-module (rnrs bytevectors) + #:use-module ((gnu build file-systems) #:select (uuid->string)) + #:re-export (uuid->string) #:export (<file-system> file-system file-system? @@ -35,6 +39,8 @@ file-system-create-mount-point? file-system->spec + string->uuid + uuid %fuse-control-file-system %binary-format-file-system @@ -106,6 +112,57 @@ initrd code." (($ <file-system> device title mount-point type flags options _ check?) (list device title mount-point type flags options check?)))) +(define %uuid-rx + ;; The regexp of a UUID. + (make-regexp "^([[:xdigit:]]{8})-([[:xdigit:]]{4})-([[:xdigit:]]{4})-([[:xdigit:]]{4})-([[:xdigit:]]{12})$")) + +(define (string->uuid str) + "Parse STR as a DCE UUID (see <https://tools.ietf.org/html/rfc4122>) and +return its contents as a 16-byte bytevector. Return #f if STR is not a valid +UUID representation." + (and=> (regexp-exec %uuid-rx str) + (lambda (match) + (letrec-syntax ((hex->number + (syntax-rules () + ((_ index) + (string->number (match:substring match index) + 16)))) + (put! + (syntax-rules () + ((_ bv index (number len) rest ...) + (begin + (bytevector-uint-set! bv index number + (endianness big) len) + (put! bv (+ index len) rest ...))) + ((_ bv index) + bv)))) + (let ((time-low (hex->number 1)) + (time-mid (hex->number 2)) + (time-hi (hex->number 3)) + (clock-seq (hex->number 4)) + (node (hex->number 5)) + (uuid (make-bytevector 16))) + (put! uuid 0 + (time-low 4) (time-mid 2) (time-hi 2) + (clock-seq 2) (node 6))))))) + +(define-syntax uuid + (lambda (s) + "Return the bytevector corresponding to the given UUID representation." + (syntax-case s () + ((_ str) + (string? (syntax->datum #'str)) + ;; A literal string: do the conversion at expansion time. + (with-syntax ((bv (string->uuid (syntax->datum #'str)))) + #''bv)) + ((_ str) + #'(string->uuid str))))) + + +;;; +;;; Common file systems. +;;; + (define %fuse-control-file-system ;; Control file system for Linux' file systems in user-space (FUSE). (file-system diff --git a/tests/file-systems.scm b/tests/file-systems.scm new file mode 100644 index 0000000000..d445b4971f --- /dev/null +++ b/tests/file-systems.scm @@ -0,0 +1,46 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2015 Ludovic Courtès <ludo@gnu.org> +;;; +;;; This file is part of GNU Guix. +;;; +;;; GNU Guix is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or (at +;;; your option) any later version. +;;; +;;; GNU Guix is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. + +(define-module (test-file-systems) + #:use-module (gnu system file-systems) + #:use-module (srfi srfi-64) + #:use-module (rnrs bytevectors)) + +;; Test the (gnu system file-systems) module. + +(test-begin "file-systems") + +(test-equal "uuid->string" + "c5307e6b-d1ba-499d-89c5-cb0b143577c4" + (uuid->string + #vu8(197 48 126 107 209 186 73 157 137 197 203 11 20 53 119 196))) + +(test-equal "string->uuid" + '(16 "4dab5feb-d176-45de-b287-9b0a6e4c01cb") + (let ((uuid (string->uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))) + (list (bytevector-length uuid) (uuid->string uuid)))) + +(test-assert "uuid" + (let ((str "4dab5feb-d176-45de-b287-9b0a6e4c01cb")) + (bytevector=? (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb") + (string->uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))) + +(test-end) + + +(exit (= (test-runner-fail-count (test-runner-current)) 0)) |