From 9b336338cdc0e46a3bf7a2913c2f61cd2410c4d6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Wed, 6 Sep 2017 09:28:28 +0200 Subject: [PATCH] system: Introduce a disjoint UUID type. Conceptually a UUID is just a bytevector. However, there's software out there such as GRUB that relies on the string representation of different UUID types (e.g., the string representation of DCE UUIDs differs from that of ISO-9660 UUIDs, even if they are actually bytevectors of the same length). This new record type allows us to preserve information about the type of UUID so we can eventually convert it to a string using the right representation. * gnu/system/uuid.scm (): New record type. (bytevector->uuid): New procedure. (uuid): Return calls to 'make-uuid'. (uuid->string): Rewrite using 'match-lambda*' to accept a single 'uuid?' argument. * gnu/bootloader/grub.scm (grub-root-search): Check for 'uuid?' instead of 'bytevector?'. * gnu/system.scm (bootable-kernel-arguments): Check whether ROOT-DEVICE is 'uuid?'. (read-boot-parameters): Use 'bytevector->uuid' when the store device is a bytevector. (read-boot-parameters-file): Check for 'uuid?' instead of 'bytevector?'. (device->sexp): New procedure. (operating-system-boot-parameters-file): Use it for 'root-device' and 'store'. (operating-system-bootcfg): Remove conditional in definition of 'root-device'. * gnu/system/file-systems.scm (file-system->spec): Check for 'uuid?' on DEVICE and take its bytevector. * gnu/system/mapped-devices.scm (open-luks-device): Likewise. * gnu/system/vm.scm (iso9660-image): Call 'uuid-bytevector' for the #:volume-uuid argument. --- gnu/bootloader/grub.scm | 4 +-- gnu/system.scm | 38 +++++++++++++++++++-------- gnu/system/file-systems.scm | 8 +++--- gnu/system/mapped-devices.scm | 7 +++-- gnu/system/uuid.scm | 48 +++++++++++++++++++++++++++++------ gnu/system/vm.scm | 4 ++- 6 files changed, 82 insertions(+), 27 deletions(-) diff --git a/gnu/bootloader/grub.scm b/gnu/bootloader/grub.scm index a9f0875f36..96e53c5c2b 100644 --- a/gnu/bootloader/grub.scm +++ b/gnu/bootloader/grub.scm @@ -30,7 +30,7 @@ (define-module (gnu bootloader grub) #:use-module (gnu artwork) #:use-module (gnu system) #:use-module (gnu bootloader) - #:use-module (gnu system file-systems) + #:use-module (gnu system uuid) #:autoload (gnu packages bootloaders) (grub) #:autoload (gnu packages compression) (gzip) #:autoload (gnu packages gtk) (guile-cairo guile-rsvg) @@ -300,7 +300,7 @@ (define (grub-root-search device file) (match device ;; Preferably refer to DEVICE by its UUID or label. This is more ;; efficient and less ambiguous, see . - ((? bytevector? uuid) + ((? uuid? uuid) (format #f "search --fs-uuid --set ~a" (uuid->string device))) ((? string? label) diff --git a/gnu/system.scm b/gnu/system.scm index 6b35e3c0c7..a8d2a81316 100644 --- a/gnu/system.scm +++ b/gnu/system.scm @@ -54,6 +54,7 @@ (define-module (gnu system) #:use-module (gnu system locale) #:use-module (gnu system pam) #:use-module (gnu system linux-initrd) + #:use-module (gnu system uuid) #:use-module (gnu system file-systems) #:use-module (gnu system mapped-devices) #:use-module (ice-9 match) @@ -128,7 +129,14 @@ (define-module (gnu system) (define (bootable-kernel-arguments kernel-arguments system.drv root-device) "Prepend extra arguments to KERNEL-ARGUMENTS that allow SYSTEM.DRV to be booted from ROOT-DEVICE" - (cons* (string-append "--root=" root-device) + (cons* (string-append "--root=" + (if (uuid? root-device) + + ;; Note: Always use the DCE format because that's + ;; what (gnu build linux-boot) expects for the + ;; '--root' kernel command-line option. + (uuid->string (uuid-bytevector root-device) 'dce) + root-device)) #~(string-append "--system=" #$system.drv) #~(string-append "--load=" #$system.drv "/boot") kernel-arguments)) @@ -261,6 +269,8 @@ (define (read-boot-parameters port) (store-device (match (assq 'store rest) + (('store ('device (? bytevector? bv)) _ ...) + (bytevector->uuid bv)) (('store ('device device) _ ...) device) (_ ;the old format @@ -289,16 +299,12 @@ (define (read-boot-parameters-file system) (let* ((file (string-append system "/parameters")) (params (call-with-input-file file read-boot-parameters)) (root (boot-parameters-root-device params)) - (root-device (if (bytevector? root) - (uuid->string root) - root)) (kernel-arguments (boot-parameters-kernel-arguments params))) (if params (boot-parameters (inherit params) (kernel-arguments (bootable-kernel-arguments kernel-arguments - system - root-device))) + system root))) #f))) (define (boot-parameters->menu-entry conf) @@ -875,9 +881,7 @@ (define* (operating-system-bootcfg os #:optional (old-entries '())) (mlet* %store-monad ((system (operating-system-derivation os)) (root-fs -> (operating-system-root-file-system os)) - (root-device -> (if (eq? 'uuid (file-system-title root-fs)) - (uuid->string (file-system-device root-fs)) - (file-system-device root-fs))) + (root-device -> (file-system-device root-fs)) (params (operating-system-boot-parameters os system root-device)) (entry -> (boot-parameters->menu-entry params)) (bootloader-conf -> (operating-system-bootloader os))) @@ -917,6 +921,15 @@ (define (operating-system-boot-parameters os system.drv root-device) (store-device (fs->boot-device store)) (store-mount-point (file-system-mount-point store)))))) +(define (device->sexp device) + "Serialize DEVICE as an sexp (really, as an object with a read syntax.)" + (match device + ((? uuid? uuid) + ;; TODO: Preserve the type of UUID. + (uuid-bytevector uuid)) + (_ + device))) + (define* (operating-system-boot-parameters-file os #:optional (system.drv #f)) "Return a file that describes the boot parameters of OS. The primary use of this file is the reconstruction of GRUB menu entries for old configurations. @@ -934,14 +947,17 @@ (define* (operating-system-boot-parameters-file os #:optional (system.drv #f)) #~(boot-parameters (version 0) (label #$(boot-parameters-label params)) - (root-device #$(boot-parameters-root-device params)) + (root-device + #$(device->sexp + (boot-parameters-root-device params))) (kernel #$(boot-parameters-kernel params)) (kernel-arguments #$(boot-parameters-kernel-arguments params)) (initrd #$(boot-parameters-initrd params)) (bootloader-name #$(boot-parameters-bootloader-name params)) (store - (device #$(boot-parameters-store-device params)) + (device + #$(device->sexp (boot-parameters-store-device params))) (mount-point #$(boot-parameters-store-mount-point params)))) #:set-load-path? #f))) diff --git a/gnu/system/file-systems.scm b/gnu/system/file-systems.scm index dd30559d7e..52f16676f5 100644 --- a/gnu/system/file-systems.scm +++ b/gnu/system/file-systems.scm @@ -20,8 +20,7 @@ (define-module (gnu system file-systems) #:use-module (ice-9 match) #:use-module (srfi srfi-1) #:use-module (guix records) - #:use-module ((gnu system uuid) - #:select (uuid string->uuid uuid->string)) + #:use-module (gnu system uuid) #:re-export (uuid ;backward compatibility string->uuid uuid->string) @@ -157,7 +156,10 @@ (define (file-system->spec fs) initrd code." (match fs (($ device title mount-point type flags options _ _ check?) - (list device title mount-point type flags options check?)))) + (list (if (uuid? device) + (uuid-bytevector device) + device) + title mount-point type flags options check?)))) (define (spec->file-system sexp) "Deserialize SEXP, a list, to the corresponding object." diff --git a/gnu/system/mapped-devices.scm b/gnu/system/mapped-devices.scm index 18b9f5b4b6..17cf6b7163 100644 --- a/gnu/system/mapped-devices.scm +++ b/gnu/system/mapped-devices.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2014, 2015, 2016 Ludovic Courtès +;;; Copyright © 2014, 2015, 2016, 2017 Ludovic Courtès ;;; Copyright © 2016 Andreas Enge ;;; Copyright © 2017 Mark H Weaver ;;; @@ -24,6 +24,7 @@ (define-module (gnu system mapped-devices) #:use-module (guix modules) #:use-module (gnu services) #:use-module (gnu services shepherd) + #:use-module (gnu system uuid) #:autoload (gnu packages cryptsetup) (cryptsetup-static) #:autoload (gnu packages linux) (mdadm-static) #:use-module (srfi srfi-1) @@ -99,7 +100,9 @@ (define (open-luks-device source target) 'cryptsetup'." (with-imported-modules (source-module-closure '((gnu build file-systems))) - #~(let ((source #$source)) + #~(let ((source #$(if (uuid? source) + (uuid-bytevector source) + source))) ;; XXX: 'use-modules' should be at the top level. (use-modules (rnrs bytevectors) ;bytevector? ((gnu build file-systems) diff --git a/gnu/system/uuid.scm b/gnu/system/uuid.scm index 64dad5a374..60626ebb12 100644 --- a/gnu/system/uuid.scm +++ b/gnu/system/uuid.scm @@ -19,12 +19,19 @@ (define-module (gnu system uuid) #:use-module (srfi srfi-1) + #:use-module (srfi srfi-9) #:use-module (rnrs bytevectors) #:use-module (ice-9 match) #:use-module (ice-9 vlist) #:use-module (ice-9 regex) #:use-module (ice-9 format) #:export (uuid + uuid? + uuid-type + uuid-bytevector + + bytevector->uuid + uuid->string dce-uuid->string string->uuid @@ -206,15 +213,27 @@ (define* (string->uuid str #:key (type 'dce)) (#f #f) ((_ . (? procedure? parse)) (parse str)))) -(define* (uuid->string bv #:key (type 'dce)) - "Convert BV, a bytevector, to the UUID string representation for TYPE." - (match (vhash-assq type %uuid-printers) - (#f #f) - ((_ . (? procedure? unparse)) (unparse bv)))) +;; High-level UUID representation that carries its type with it. +;; +;; This is necessary to serialize bytevectors with the right printer in some +;; circumstances. For instance, GRUB "search --fs-uuid" command compares the +;; string representation of UUIDs, not the raw bytes; thus, when emitting a +;; GRUB 'search' command, we need to procedure the right string representation +;; (see ). +(define-record-type + (make-uuid type bv) + uuid? + (type uuid-type) ;'dce | 'iso9660 | ... + (bv uuid-bytevector)) + +(define* (bytevector->uuid bv #:optional (type 'dce)) + "Return a UUID object make of BV and TYPE." + (make-uuid type bv)) (define-syntax uuid (lambda (s) - "Return the bytevector corresponding to the given UUID representation." + "Return the UUID object corresponding to the given UUID representation." + ;; TODO: Extend to types other than DCE. (syntax-case s () ((_ str) (string? (syntax->datum #'str)) @@ -222,6 +241,19 @@ (define-syntax uuid (let ((bv (string->uuid (syntax->datum #'str)))) (unless bv (syntax-violation 'uuid "invalid UUID" s)) - (datum->syntax #'str bv))) + #`(make-uuid 'dce #,(datum->syntax #'str bv)))) ((_ str) - #'(string->uuid str))))) + #'(make-uuid 'dce (string->uuid str)))))) + +(define uuid->string + ;; Convert the given bytevector or UUID object, to the corresponding UUID + ;; string representation. + (match-lambda* + (((? bytevector? bv)) + (uuid->string bv 'dce)) + (((? bytevector? bv) type) + (match (vhash-assq type %uuid-printers) + (#f #f) + ((_ . (? procedure? unparse)) (unparse bv)))) + (((? uuid? uuid)) + (uuid->string (uuid-bytevector uuid) (uuid-type uuid))))) diff --git a/gnu/system/vm.scm b/gnu/system/vm.scm index b106dff0a8..92f0444ed8 100644 --- a/gnu/system/vm.scm +++ b/gnu/system/vm.scm @@ -57,6 +57,7 @@ (define-module (gnu system vm) #:use-module (gnu system file-systems) #:use-module (gnu system) #:use-module (gnu services) + #:use-module (gnu system uuid) #:use-module (srfi srfi-1) #:use-module (srfi srfi-26) @@ -231,7 +232,8 @@ (define* (iso9660-image #:key #:register-closures? #$register-closures? #:closures graphs #:volume-id #$file-system-label - #:volume-uuid #$file-system-uuid) + #:volume-uuid #$(and=> file-system-uuid + uuid-bytevector)) (reboot)))) #:system system #:make-disk-image? #f