;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2013, 2014, 2015 Ludovic Courtès ;;; ;;; 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 . (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-device file-system-title file-system-mount-point file-system-type file-system-needed-for-boot? file-system-flags file-system-options file-system-check? file-system-create-mount-point? file-system-dependencies file-system->spec string->uuid uuid %fuse-control-file-system %binary-format-file-system %shared-memory-file-system %pseudo-terminal-file-system %devtmpfs-file-system %immutable-store %control-groups %base-file-systems %container-file-systems mapped-device mapped-device? mapped-device-source mapped-device-target mapped-device-type mapped-device-kind mapped-device-kind? mapped-device-kind-open mapped-device-kind-close file-system-mapping file-system-mapping? file-system-mapping-source file-system-mapping-target file-system-mapping-writable? %store-mapping)) ;;; Commentary: ;;; ;;; Declaring file systems to be mounted. ;;; ;;; Code: ;; File system declaration. (define-record-type* file-system make-file-system file-system? (device file-system-device) ; string (title file-system-title ; 'device | 'label | 'uuid (default 'device)) (mount-point file-system-mount-point) ; string (type file-system-type) ; string (flags file-system-flags ; list of symbols (default '())) (options file-system-options ; string or #f (default #f)) (needed-for-boot? %file-system-needed-for-boot? ; Boolean (default #f)) (check? file-system-check? ; Boolean (default #t)) (create-mount-point? file-system-create-mount-point? ; Boolean (default #f)) (dependencies file-system-dependencies ; list of strings (mount ; points depended on) (default '()))) (define-inlinable (file-system-needed-for-boot? fs) "Return true if FS has the 'needed-for-boot?' flag set, or if it's the root file system." (or (%file-system-needed-for-boot? fs) (string=? "/" (file-system-mount-point fs)))) (define (file-system->spec fs) "Return a list corresponding to file-system FS that can be passed to the initrd code." (match fs (($ 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 ) 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. (let ((bv (string->uuid (syntax->datum #'str)))) (unless bv (syntax-violation 'uuid "invalid UUID" s)) (datum->syntax #'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 (device "fusectl") (mount-point "/sys/fs/fuse/connections") (type "fusectl") (check? #f))) (define %binary-format-file-system ;; Support for arbitrary executable binary format. (file-system (device "binfmt_misc") (mount-point "/proc/sys/fs/binfmt_misc") (type "binfmt_misc") (check? #f))) (define %devtmpfs-file-system ;; /dev as a 'devtmpfs' file system, needed for udev. (file-system (device "none") (mount-point "/dev") (type "devtmpfs") (check? #f) ;; Mount it from the initrd so /dev/pts & co. can then be mounted over it. (needed-for-boot? #t))) (define %tty-gid ;; ID of the 'tty' group. Allocate it statically to make it easy to refer ;; to it from here and from the 'tty' group definitions. 996) (define %pseudo-terminal-file-system ;; The pseudo-terminal file system. It needs to be mounted so that ;; statfs(2) returns DEVPTS_SUPER_MAGIC like libc's getpt(3) expects (and ;; thus openpty(3) and its users, such as xterm.) (file-system (device "none") (mount-point "/dev/pts") (type "devpts") (check? #f) (needed-for-boot? #f) (create-mount-point? #t) (options (string-append "gid=" (number->string %tty-gid) ",mode=620")))) (define %shared-memory-file-system ;; Shared memory. (file-system (device "tmpfs") (mount-point "/dev/shm") (type "tmpfs") (check? #f) (flags '(no-suid no-dev)) (options "size=50%") ;TODO: make size configurable (create-mount-point? #t))) (define %immutable-store ;; Read-only store to avoid users or daemons accidentally modifying it. ;; 'guix-daemon' has provisions to remount it read-write in its own name ;; space. (file-system (device (%store-prefix)) (mount-point (%store-prefix)) (type "none") (check? #f) (flags '(read-only bind-mount)))) (define %control-groups (let ((parent (file-system (device "cgroup") (mount-point "/sys/fs/cgroup") (type "tmpfs") (check? #f)))) (cons parent (map (lambda (subsystem) (file-system (device "cgroup") (mount-point (string-append "/sys/fs/cgroup/" subsystem)) (type "cgroup") (check? #f) (options subsystem) (create-mount-point? #t) ;; This must be mounted after, and unmounted before the ;; parent directory. (dependencies (list parent)))) '("cpuset" "cpu" "cpuacct" "memory" "devices" "freezer" "blkio" "perf_event" "hugetlb"))))) (define %base-file-systems ;; List of basic file systems to be mounted. Note that /proc and /sys are ;; currently mounted by the initrd. (append (list %devtmpfs-file-system %pseudo-terminal-file-system %shared-memory-file-system %immutable-store) %control-groups)) ;; File systems for Linux containers differ from %base-file-systems in that ;; they impose additional restrictions such as no-exec or need different ;; options to function properly. ;; ;; The file system flags and options conform to the libcontainer ;; specification: ;; https://github.com/docker/libcontainer/blob/master/SPEC.md#filesystem (define %container-file-systems (list ;; Pseudo-terminal file system. (file-system (device "none") (mount-point "/dev/pts") (type "devpts") (flags '(no-exec no-suid)) (needed-for-boot? #t) (create-mount-point? #t) (check? #f) (options "newinstance,ptmxmode=0666,mode=620")) ;; Shared memory file system. (file-system (device "tmpfs") (mount-point "/dev/shm") (type "tmpfs") (flags '(no-exec no-suid no-dev)) (options "mode=1777,size=65536k") (needed-for-boot? #t) (create-mount-point? #t) (check? #f)) ;; Message queue file system. (file-system (device "mqueue") (mount-point "/dev/mqueue") (type "mqueue") (flags '(no-exec no-suid no-dev)) (needed-for-boot? #t) (create-mount-point? #t) (check? #f)))) ;;; ;;; 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 (type mapped-device-type)) ; (define-record-type* mapped-device-kind make-mapped-device-kind mapped-device-kind? (open mapped-device-kind-open) ;source target -> gexp (close mapped-device-kind-close ;source target -> gexp (default (const #~(const #f))))) ;;; ;;; Shared file systems, for VMs/containers. ;;; ;; Mapping of host file system SOURCE to mount point TARGET in the guest. (define-record-type* file-system-mapping make-file-system-mapping file-system-mapping? (source file-system-mapping-source) ;string (target file-system-mapping-target) ;string (writable? file-system-mapping-writable? ;Boolean (default #f))) (define %store-mapping ;; Mapping of the host's store into the guest. (file-system-mapping (source (%store-prefix)) (target (%store-prefix)) (writable? #f))) ;;; file-systems.scm ends here