From 5dae0186dea1e72e73bf223161620cfeddef5a63 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Thu, 11 Sep 2014 23:39:15 +0200 Subject: [PATCH] system: Add support for Linux-style mapped devices. * gnu/system/file-systems.scm (): New record type. * gnu/system.scm ()[mapped-devices]: New field. (luks-device-mapping): New procedure. (other-file-system-services)[device-mappings, requirements]: New procedures. Pass #:requirements to 'file-system-service'. (device-mapping-services): New procedure. (essential-services): Use it. Append its result to the return value. (operating-system-initrd-file): Add comment. * gnu/services/base.scm (file-system-service): Add #:requirements parameter and honor it. (device-mapping-service): New procedure. * gnu/system/linux-initrd.scm (base-initrd): Add comment. --- gnu/services/base.scm | 24 +++++++++++-- gnu/system.scm | 67 ++++++++++++++++++++++++++++++------- gnu/system/file-systems.scm | 21 +++++++++++- gnu/system/linux-initrd.scm | 1 + 4 files changed, 97 insertions(+), 16 deletions(-) diff --git a/gnu/services/base.scm b/gnu/services/base.scm index bf5af8369e..014eef053b 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -38,6 +38,7 @@ #:use-module (ice-9 format) #:export (root-file-system-service file-system-service + device-mapping-service user-processes-service host-name-service console-font-service @@ -99,18 +100,20 @@ This service must be the root of the service dependency graph so that its (define* (file-system-service device target type #:key (flags '()) (check? #t) - create-mount-point? options (title 'any)) + create-mount-point? options (title 'any) + (requirements '())) "Return a service that mounts DEVICE on TARGET as a file system TYPE with OPTIONS. TITLE is a symbol specifying what kind of name DEVICE is: 'label for a partition label, 'device for a device file name, or 'any. When CHECK? is true, check the file system before mounting it. When CREATE-MOUNT-POINT? is true, create TARGET if it does not exist yet. FLAGS is a list of symbols, -such as 'read-only' etc." +such as 'read-only' etc. Optionally, REQUIREMENTS may be a list of service +names such as device-mapping services." (with-monad %store-monad (return (service (provision (list (symbol-append 'file-system- (string->symbol target)))) - (requirement '(root-file-system)) + (requirement `(root-file-system ,@requirements)) (documentation "Check, mount, and unmount the given file system.") (start #~(lambda args (let ((device (canonicalize-device-spec #$device '#$title))) @@ -567,6 +570,21 @@ extra rules from the packages listed in @var{rules}." pid))))) (stop #~(make-kill-destructor)))))) +(define (device-mapping-service target command) + "Return a service that maps device @var{target}, a string such as +@code{\"home\"} (meaning @code{/dev/mapper/home}), by executing @var{command}, +a gexp." + (with-monad %store-monad + (return (service + (provision (list (symbol-append 'device-mapping- + (string->symbol target)))) + (requirement '(udev)) + (documentation "Map a device node using Linux's device mapper.") + (start #~(lambda () + #$command)) + (stop #~(const #f)) + (respawn? #f))))) + (define %base-services ;; Convenience variable holding the basic services. (let ((motd (text-file "motd" " diff --git a/gnu/system.scm b/gnu/system.scm index 8a3f4f6ba8..9bdf227eca 100644 --- a/gnu/system.scm +++ b/gnu/system.scm @@ -44,6 +44,7 @@ #:use-module (gnu system linux) #:use-module (gnu system linux-initrd) #:use-module (gnu system file-systems) + #:autoload (gnu packages cryptsetup) (cryptsetup) #:use-module (ice-9 match) #:use-module (srfi srfi-1) #:use-module (srfi srfi-26) @@ -64,6 +65,7 @@ operating-system-packages operating-system-timezone operating-system-locale + operating-system-mapped-devices operating-system-file-systems operating-system-activation-script @@ -72,7 +74,9 @@ operating-system-grub.cfg %setuid-programs - %base-packages)) + %base-packages + + luks-device-mapping)) ;;; Commentary: ;;; @@ -96,6 +100,8 @@ (hosts-file operating-system-hosts-file ; M item | #f (default #f)) + (mapped-devices operating-system-mapped-devices ; list of + (default '())) (file-systems operating-system-file-systems) ; list of fs (users operating-system-users ; list of user accounts @@ -152,6 +158,13 @@ file." ;;; Services. ;;; +(define (luks-device-mapping source target) + "Return a gexp that maps SOURCE to TARGET as a LUKS device, using +'cryptsetup'." + #~(zero? (system* (string-append #$cryptsetup "/sbin/cryptsetup") + "open" "--type" "luks" + #$source #$target))) + (define (other-file-system-services os) "Return file system services for the file systems of OS that are not marked as 'needed-for-boot'." @@ -161,30 +174,58 @@ as 'needed-for-boot'." (string=? "/" (file-system-mount-point fs)))) (operating-system-file-systems os))) + (define (device-mappings fs) + (filter (lambda (md) + (string=? (string-append "/dev/mapper/" + (mapped-device-target md)) + (file-system-device fs))) + (operating-system-mapped-devices os))) + + (define (requirements fs) + (map (lambda (md) + (symbol-append 'device-mapping- + (string->symbol (mapped-device-target md)))) + (device-mappings fs))) + (sequence %store-monad - (map (match-lambda - (($ device title target type flags opts - #f check? create?) - (file-system-service device target type - #:title title - #:check? check? - #:create-mount-point? create? - #:options opts - #:flags flags))) + (map (lambda (fs) + (match fs + (($ device title target type flags opts + #f check? create?) + (file-system-service device target type + #:title title + #:requirements (requirements fs) + #:check? check? + #:create-mount-point? create? + #:options opts + #:flags flags)))) file-systems))) +(define (device-mapping-services os) + "Return the list of device-mapping services for OS as a monadic list." + (sequence %store-monad + (map (lambda (md) + (let ((source (mapped-device-source md)) + (target (mapped-device-target md)) + (command (mapped-device-command md))) + (device-mapping-service target + (command source target)))) + (operating-system-mapped-devices os)))) + (define (essential-services os) "Return the list of essential services for OS. These are special services that implement part of what's declared in OS are responsible for low-level bookkeeping." - (mlet* %store-monad ((root-fs (root-file-system-service)) + (mlet* %store-monad ((mappings (device-mapping-services os)) + (root-fs (root-file-system-service)) (other-fs (other-file-system-services os)) (procs (user-processes-service (map (compose first service-provision) other-fs))) (host-name (host-name-service (operating-system-host-name os)))) - (return (cons* host-name procs root-fs other-fs)))) + (return (cons* host-name procs root-fs + (append other-fs mappings))))) (define (operating-system-services os) "Return all the services of OS, including \"internal\" services that do not @@ -490,6 +531,8 @@ we're running in the final root." boot?)) (operating-system-file-systems os))) + ;; TODO: Pass the mapped devices required by boot-time file systems to the + ;; initrd. (mlet %store-monad ((initrd ((operating-system-initrd os) boot-file-systems))) (return #~(string-append #$initrd "/initrd")))) diff --git a/gnu/system/file-systems.scm b/gnu/system/file-systems.scm index 48c4fc7e77..90e2b0c796 100644 --- a/gnu/system/file-systems.scm +++ b/gnu/system/file-systems.scm @@ -37,7 +37,13 @@ %pseudo-terminal-file-system %devtmpfs-file-system - %base-file-systems)) + %base-file-systems + + mapped-device + mapped-device? + mapped-device-source + mapped-device-target + mapped-device-command)) ;;; Commentary: ;;; @@ -128,4 +134,17 @@ %pseudo-terminal-file-system %shared-memory-file-system)) + + +;;; +;;; Mapped devices, for Linux's device-mapper. +;;; + +(define-record-type* mapped-device + make-mapped-device + mapped-device? + (source mapped-device-source) ;string + (target mapped-device-target) ;string + (command mapped-device-command)) ;source target -> gexp + ;;; file-systems.scm ends here diff --git a/gnu/system/linux-initrd.scm b/gnu/system/linux-initrd.scm index e83a9a5b23..93f751b757 100644 --- a/gnu/system/linux-initrd.scm +++ b/gnu/system/linux-initrd.scm @@ -131,6 +131,7 @@ initrd code." volatile-root? (extra-modules '()) guile-modules-in-chroot?) + ;; TODO: Support boot-time device mappings. "Return a monadic derivation that builds a generic initrd. FILE-SYSTEMS is a list of file-systems to be mounted by the initrd, possibly in addition to the root file system specified on the kernel command line via '--root'.