* gnu/build/file-systems (canonicalize-device-name): Fallback to tmpfs if spec is "none". Change-Id: Ia55c715d04c7611ba8c979f23f1ad4a8ed2e75b6 Signed-off-by: Ludovic Courtès <ludo@gnu.org>
		
			
				
	
	
		
			1230 lines
		
	
	
	
		
			48 KiB
		
	
	
	
		
			Scheme
		
	
	
	
	
	
			
		
		
	
	
			1230 lines
		
	
	
	
		
			48 KiB
		
	
	
	
		
			Scheme
		
	
	
	
	
	
| ;;; GNU Guix --- Functional package management for GNU
 | ||
| ;;; Copyright © 2014-2018, 2020-2022 Ludovic Courtès <ludo@gnu.org>
 | ||
| ;;; Copyright © 2016, 2017 David Craven <david@craven.ch>
 | ||
| ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
 | ||
| ;;; Copyright © 2019 Guillaume Le Vaillant <glv@posteo.net>
 | ||
| ;;; Copyright © 2019–2021 Tobias Geerinckx-Rice <me@tobias.gr>
 | ||
| ;;; Copyright © 2019 David C. Trudgian <dave@trudgian.net>
 | ||
| ;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 | ||
| ;;; Copyright © 2022 Oleg Pykhalov <go.wigust@gmail.com>
 | ||
| ;;; Copyright © 2024 Nicolas Graves <ngraves@ngraves.fr>
 | ||
| ;;;
 | ||
| ;;; 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 (gnu build file-systems)
 | ||
|   #:use-module (gnu system uuid)
 | ||
|   #:use-module (gnu system file-systems)
 | ||
|   #:use-module (guix build utils)
 | ||
|   #:use-module (guix build bournish)
 | ||
|   #:use-module ((guix build syscalls)
 | ||
|                 #:hide (file-system-type))
 | ||
|   #:use-module (guix diagnostics)
 | ||
|   #:use-module (guix i18n)
 | ||
|   #:use-module (rnrs io ports)
 | ||
|   #:use-module (rnrs bytevectors)
 | ||
|   #:use-module (ice-9 match)
 | ||
|   #:use-module (ice-9 rdelim)
 | ||
|   #:use-module (system foreign)
 | ||
|   #:autoload   (system repl repl) (start-repl)
 | ||
|   #:use-module (srfi srfi-1)
 | ||
|   #:use-module (srfi srfi-26)
 | ||
|   #:export (disk-partitions
 | ||
|             partition-label-predicate
 | ||
|             partition-uuid-predicate
 | ||
|             partition-luks-uuid-predicate
 | ||
|             find-partition-by-label
 | ||
|             find-partition-by-uuid
 | ||
|             find-partition-by-luks-uuid
 | ||
|             canonicalize-device-spec
 | ||
| 
 | ||
|             read-partition-label
 | ||
|             read-partition-uuid
 | ||
|             read-luks-partition-uuid
 | ||
| 
 | ||
|             cleanly-unmounted-ext2?
 | ||
| 
 | ||
|             bind-mount
 | ||
| 
 | ||
|             system*/tty
 | ||
|             mount-flags->bit-mask
 | ||
|             check-file-system
 | ||
|             mount-file-system
 | ||
| 
 | ||
|             swap-space->flags-bit-mask))
 | ||
| 
 | ||
| ;;; Commentary:
 | ||
| ;;;
 | ||
| ;;; This modules provides tools to deal with disk partitions, and to mount and
 | ||
| ;;; check file systems.
 | ||
| ;;;
 | ||
| ;;; Code:
 | ||
| 
 | ||
| (define (system*/console program . args)
 | ||
|   "Run PROGRAM with ARGS in a tty on top of /dev/console.  The return value is
 | ||
| as for 'system*'."
 | ||
|   (match (primitive-fork)
 | ||
|     (0
 | ||
|      (dynamic-wind
 | ||
|        (const #t)
 | ||
|        (lambda ()
 | ||
|          (login-tty (open-fdes "/dev/console" O_RDWR))
 | ||
|          (apply execlp program program args))
 | ||
|        (lambda ()
 | ||
|          (primitive-_exit 127))))
 | ||
|     (pid
 | ||
|      (cdr (waitpid pid)))))
 | ||
| 
 | ||
| (define (system*/tty program . args)
 | ||
|   "Run PROGRAM with ARGS, creating a tty if its standard input isn't one.
 | ||
| The return value is as for 'system*'.
 | ||
| 
 | ||
| This is necessary for commands such as 'cryptsetup open' or 'fsck' that may
 | ||
| need to interact with the user but might be invoked from shepherd, where
 | ||
| standard input is /dev/null."
 | ||
|   (apply (if (isatty? (current-input-port))
 | ||
|              system*
 | ||
|              system*/console)
 | ||
|          program args))
 | ||
| 
 | ||
| (define (call-with-input-file file proc)
 | ||
|   "Like 'call-with-input-file', but pass O_CLOEXEC."
 | ||
|   (let ((port #f))
 | ||
|     (dynamic-wind
 | ||
|       (lambda ()
 | ||
|         (set! port (open file (logior O_RDONLY O_CLOEXEC))))
 | ||
|       (lambda ()
 | ||
|         (proc port))
 | ||
|       (lambda ()
 | ||
|         (close-port port)
 | ||
|         (set! port #f)))))
 | ||
| 
 | ||
| (define (bind-mount source target)
 | ||
|   "Bind-mount SOURCE at TARGET."
 | ||
|   (mount source target "" MS_BIND))
 | ||
| 
 | ||
| (define (seek* fd/port offset whence)
 | ||
|   "Like 'seek' but return -1 instead of throwing to 'system-error' upon
 | ||
| EINVAL.  This makes it easier to catch cases like OFFSET being too large for
 | ||
| FD/PORT."
 | ||
|   (catch 'system-error
 | ||
|     (lambda ()
 | ||
|       (seek fd/port offset whence))
 | ||
|     (lambda args
 | ||
|       (if (= EINVAL (system-error-errno args))
 | ||
|           -1
 | ||
|           (apply throw args)))))
 | ||
| 
 | ||
| (define (read-superblock device offset size magic?)
 | ||
|   "Read a superblock of SIZE from OFFSET and DEVICE.  Return the raw
 | ||
| superblock on success, and #f if no valid superblock was found.  MAGIC?
 | ||
| takes a bytevector and returns #t when it's a valid superblock."
 | ||
|   (call-with-input-file device
 | ||
|     (lambda (port)
 | ||
|       (and (= offset (seek* port offset SEEK_SET))
 | ||
|            (let ((block (make-bytevector size)))
 | ||
|              (match (get-bytevector-n! port block 0 (bytevector-length block))
 | ||
|                ((? eof-object?)
 | ||
|                 #f)
 | ||
|                ((? number? len)
 | ||
|                 (and (= len (bytevector-length block))
 | ||
|                      (and (magic? block)
 | ||
|                           block)))))))))
 | ||
| 
 | ||
| (define null-terminated-latin1->string
 | ||
|   (cut latin1->string <> zero?))
 | ||
| 
 | ||
| (define (bytevector-utf16-length bv)
 | ||
|   "Given a bytevector BV containing a NUL-terminated UTF16-encoded string,
 | ||
| determine where the NUL terminator is and return its index.  If there's no
 | ||
| NUL terminator, return the size of the bytevector."
 | ||
|   (let ((length (bytevector-length bv)))
 | ||
|     (let loop ((index 0))
 | ||
|       (if (< index length)
 | ||
|           (if (zero? (bytevector-u16-ref bv index 'little))
 | ||
|               index
 | ||
|               (loop (+ index 2)))
 | ||
|           length))))
 | ||
| 
 | ||
| (define* (bytevector->u16-list bv endianness #:optional (index 0))
 | ||
|   (if (< index (bytevector-length bv))
 | ||
|       (cons (bytevector-u16-ref bv index endianness)
 | ||
|             (bytevector->u16-list bv endianness (+ index 2)))
 | ||
|       '()))
 | ||
| 
 | ||
| ;; The initrd doesn't have iconv data, so do the conversion ourselves.
 | ||
| (define (utf16->string bv endianness)
 | ||
|   (list->string
 | ||
|    (map integer->char
 | ||
|         (reverse
 | ||
|          (let loop ((remainder (bytevector->u16-list bv endianness))
 | ||
|                     (result '()))
 | ||
|              (match remainder
 | ||
|               (() result)
 | ||
|               ((a) (cons a result))
 | ||
|               ((a b x ...)
 | ||
|                (if (and (>= a #xD800) (< a #xDC00) ; high surrogate
 | ||
|                         (>= b #xDC00) (< b #xE000)) ; low surrogate
 | ||
|                    (loop x (cons (+ #x10000
 | ||
|                                     (* #x400 (- a #xD800))
 | ||
|                                     (- b #xDC00))
 | ||
|                                  result))
 | ||
|                    (loop (cons b x) (cons a result))))))))))
 | ||
| 
 | ||
| (define (null-terminated-utf16->string bv endianness)
 | ||
|   (utf16->string (sub-bytevector bv 0 (bytevector-utf16-length bv))
 | ||
|                  endianness))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; Ext2 file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; <http://www.nongnu.org/ext2-doc/ext2.html#DEF-SUPERBLOCK>.
 | ||
| ;; TODO: Use "packed structs" from Guile-OpenGL or similar.
 | ||
| 
 | ||
| (define-syntax %ext2-endianness
 | ||
|   ;; Endianness of ext2 file systems.
 | ||
|   (identifier-syntax (endianness little)))
 | ||
| 
 | ||
| (define (ext2-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is an ext2 superblock."
 | ||
|   (let ((magic (bytevector-u16-ref sblock 56 %ext2-endianness)))
 | ||
|     (= magic #xef53)))
 | ||
| 
 | ||
| (define (read-ext2-superblock device)
 | ||
|   "Return the raw contents of DEVICE's ext2 superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain an ext2 file system."
 | ||
|   (read-superblock device 1024 264 ext2-superblock?))
 | ||
| 
 | ||
| (define (ext2-superblock-cleanly-unmounted? sblock)
 | ||
|   "Return true if SBLOCK denotes a file system that was cleanly unmounted,
 | ||
| false otherwise."
 | ||
|   (define EXT2_VALID_FS 1)                        ;cleanly unmounted
 | ||
|   (define EXT2_ERROR_FS 2)                        ;errors detected
 | ||
| 
 | ||
|   (define EXT3_FEATURE_INCOMPAT_RECOVER #x0004)   ;journal needs recovery
 | ||
| 
 | ||
|   (let ((state (bytevector-u16-ref sblock 58 %ext2-endianness)))
 | ||
|     (cond ((= state EXT2_VALID_FS)
 | ||
|            (let ((incompatible-features
 | ||
|                   (bytevector-u32-ref sblock 96 %ext2-endianness)))
 | ||
|              (zero? (logand incompatible-features
 | ||
|                             EXT3_FEATURE_INCOMPAT_RECOVER))))
 | ||
|           ((= state EXT2_ERROR_FS) #f)
 | ||
|           (else (error "invalid ext2 superblock state" state)))))
 | ||
| 
 | ||
| (define (ext2-superblock-uuid sblock)
 | ||
|   "Return the UUID of ext2 superblock SBLOCK as a 16-byte bytevector."
 | ||
|   (sub-bytevector sblock 104 16))
 | ||
| 
 | ||
| (define (ext2-superblock-volume-name sblock)
 | ||
|   "Return the volume name of ext2 superblock SBLOCK as a string of at most 16
 | ||
| characters, or #f if SBLOCK has no volume name."
 | ||
|   (null-terminated-latin1->string (sub-bytevector sblock 120 16)))
 | ||
| 
 | ||
| (define (check-ext2-file-system device force? repair)
 | ||
|   "Return the health of an unmounted ext2 file system on DEVICE.  If FORCE? is
 | ||
| true, check the file system even if it's marked as clean.  If REPAIR is false,
 | ||
| do not write to the file system to fix errors.  If it's #t, fix all
 | ||
| errors.  Otherwise, fix only those considered safe to repair automatically."
 | ||
|   (match (status:exit-val
 | ||
|           (apply system*/tty "e2fsck" "-v" "-C" "0"
 | ||
|                  `(,@(if force? '("-f") '())
 | ||
|                    ,@(match repair
 | ||
|                        (#f '("-n"))
 | ||
|                        (#t '("-y"))
 | ||
|                        (_  '("-p")))
 | ||
|                    ,device)))
 | ||
|     (0 'pass)
 | ||
|     (1 'errors-corrected)
 | ||
|     (2 'reboot-required)
 | ||
|     (_ 'fatal-error)))
 | ||
| 
 | ||
| (define (cleanly-unmounted-ext2? device)          ;convenience procedure
 | ||
|   "Return true if DEVICE is an ext2 file system and if it was cleanly
 | ||
| unmounted."
 | ||
|   (ext2-superblock-cleanly-unmounted? (read-ext2-superblock device)))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; Linux swap.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; Linux "swap space" is not a file system but it has a UUID and volume name,
 | ||
| ;; like actual file systems, and we want to be able to look up swap partitions
 | ||
| ;; by UUID and by label.
 | ||
| 
 | ||
| (define %linux-swap-magic
 | ||
|   (string->utf8 "SWAPSPACE2"))
 | ||
| 
 | ||
| ;; Like 'PAGE_SIZE' in Linux, arch/x86/include/asm/page.h.
 | ||
| ;; XXX: This is always 4K on x86_64, i386, and ARMv7.  However, on AArch64,
 | ||
| ;; this is determined by 'CONFIG_ARM64_PAGE_SHIFT' in the kernel, which is 12
 | ||
| ;; by default (4K) but can be 14 or 16.
 | ||
| (define %page-size 4096)
 | ||
| 
 | ||
| (define (linux-swap-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is an linux-swap superblock."
 | ||
|   (and (= (bytevector-length sblock) %page-size)
 | ||
|        (bytevector=? (sub-bytevector sblock (- %page-size 10) 10)
 | ||
|                      %linux-swap-magic)))
 | ||
| 
 | ||
| (define (read-linux-swap-superblock device)
 | ||
|   "Return the raw contents of DEVICE's linux-swap superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain an linux-swap file system."
 | ||
|   (read-superblock device 0 %page-size linux-swap-superblock?))
 | ||
| 
 | ||
| ;; See 'union swap_header' in 'include/linux/swap.h'.
 | ||
| 
 | ||
| (define (linux-swap-superblock-uuid sblock)
 | ||
|   "Return the UUID of Linux-swap superblock SBLOCK as a 16-byte bytevector."
 | ||
|   (sub-bytevector sblock (+ 1024 4 4 4) 16))
 | ||
| 
 | ||
| (define (linux-swap-superblock-volume-name sblock)
 | ||
|   "Return the label of Linux-swap superblock SBLOCK as a string."
 | ||
|   (null-terminated-latin1->string
 | ||
|    (sub-bytevector sblock (+ 1024 4 4 4 16) 16)))
 | ||
| 
 | ||
| (define (swap-space->flags-bit-mask swap)
 | ||
|   "Return the number suitable for the 'flags' argument of 'mount'
 | ||
| that corresponds to the swap-space SWAP."
 | ||
|   (define prio-flag
 | ||
|     (let ((p (swap-space-priority swap))
 | ||
|           (max (ash SWAP_FLAG_PRIO_MASK (- SWAP_FLAG_PRIO_SHIFT))))
 | ||
|       (if p
 | ||
|           (logior SWAP_FLAG_PREFER
 | ||
|                   (ash (cond
 | ||
|                         ((< p 0)
 | ||
|                          (begin (warning
 | ||
|                                  (G_ "Given swap priority ~a is
 | ||
| negative, defaulting to 0.~%") p)
 | ||
|                                 0))
 | ||
|                         ((> p max)
 | ||
|                          (begin (warning
 | ||
|                                  (G_ "Limiting swap priority ~a to
 | ||
| ~a.~%")
 | ||
|                                  p max)
 | ||
|                                 max))
 | ||
|                         (else p))
 | ||
|                        SWAP_FLAG_PRIO_SHIFT))
 | ||
|           0)))
 | ||
|   (define delayed-flag
 | ||
|     (if (swap-space-discard? swap)
 | ||
|         SWAP_FLAG_DISCARD
 | ||
|         0))
 | ||
|   (logior prio-flag delayed-flag))
 | ||
| 
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; Bcachefs file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; <https://evilpiepirate.org/git/bcachefs-tools.git/tree/libbcachefs/bcachefs_format.h>
 | ||
| 
 | ||
| (define-syntax %bcachefs-endianness
 | ||
|   ;; Endianness of bcachefs file systems.
 | ||
|   (identifier-syntax (endianness little)))
 | ||
| 
 | ||
| (define (bcachefs-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is an bcachefs superblock."
 | ||
|   (bytevector=? (sub-bytevector sblock 24 16)
 | ||
|                 #vu8(#xc6 #x85 #x73 #xf6 #x4e #x1a #x45 #xca
 | ||
|                      #x82 #x65 #xf5 #x7f #x48 #xba #x6d #x81)))
 | ||
| 
 | ||
| (define (read-bcachefs-superblock device)
 | ||
|   "Return the raw contents of DEVICE's bcachefs superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain a bcachefs file system."
 | ||
|   ;; Field offsets & lengths, in bytes.  There are more (and the superblock is
 | ||
|   ;; extensible) but we need only some basic information here:
 | ||
|   ;;  0 16 bch_csum
 | ||
|   ;; 16  8 version
 | ||
|   ;; 24 16 magic
 | ||
|   ;; 40 16 uuid               ← ‘internal’: you probably don't want this one
 | ||
|   ;; 56 16 user_uuid          ← ‘external’: user-visible one by which to mount
 | ||
|   ;; 72 32 label
 | ||
|   ;; Assume a sane file system: ignore the back-up superblock & checksums.
 | ||
|   (read-superblock device 4096 104 bcachefs-superblock?))
 | ||
| 
 | ||
| (define (bcachefs-superblock-external-uuid sblock)
 | ||
|   "Return the external UUID of bcachefs superblock SBLOCK as a 16-byte
 | ||
| bytevector."
 | ||
|   (sub-bytevector sblock 56 16))
 | ||
| 
 | ||
| (define (bcachefs-superblock-volume-name sblock)
 | ||
|   "Return the volume name of bcachefs superblock SBLOCK as a string of at most
 | ||
| 32 characters, or #f if SBLOCK has no volume name."
 | ||
|   (null-terminated-latin1->string (sub-bytevector sblock 72 32)))
 | ||
| 
 | ||
| (define (check-bcachefs-file-system device force? repair)
 | ||
|   "Return the health of an unmounted bcachefs file system on DEVICE.  If FORCE?
 | ||
| is true, check the file system even if it's marked as clean.  If REPAIR is
 | ||
| false, do not write to the file system to fix errors.  If it's #t, fix all
 | ||
| errors. Otherwise, fix only those considered safe to repair automatically."
 | ||
|   (let ((ignored-bits (logior 2))       ; DEVICE was mounted read-only
 | ||
|         (status
 | ||
|          ;; A number, or #f on abnormal termination (e.g., assertion failure).
 | ||
|          (status:exit-val
 | ||
|           (apply system*/tty "bcachefs" "fsck" "-v"
 | ||
|                  `(,@(if force? '("-f") '())
 | ||
|                    ,@(match repair
 | ||
|                        (#f '("-n"))
 | ||
|                        (#t '("-y"))
 | ||
|                        (_  '("-p")))
 | ||
|                    ;; Make each multi-device member a separate argument.
 | ||
|                    ,@(string-split device #\:))))))
 | ||
|     (match (and=> status (cut logand <> (lognot ignored-bits)))
 | ||
|       (0 'pass)
 | ||
|       (1 'errors-corrected)
 | ||
|       (_ 'fatal-error))))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; Btrfs file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; <https://btrfs.wiki.kernel.org/index.php/On-disk_Format#Superblock>.
 | ||
| 
 | ||
| (define-syntax %btrfs-endianness
 | ||
|   ;; Endianness of btrfs file systems.
 | ||
|   (identifier-syntax (endianness little)))
 | ||
| 
 | ||
| (define (btrfs-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is a btrfs superblock."
 | ||
|   (bytevector=? (sub-bytevector sblock 64 8)
 | ||
|                 (string->utf8 "_BHRfS_M")))
 | ||
| 
 | ||
| (define (read-btrfs-superblock device)
 | ||
|   "Return the raw contents of DEVICE's btrfs superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain a btrfs file system."
 | ||
|   (read-superblock device 65536 4096 btrfs-superblock?))
 | ||
| 
 | ||
| (define (btrfs-superblock-uuid sblock)
 | ||
|   "Return the UUID of a btrfs superblock SBLOCK as a 16-byte bytevector."
 | ||
|   (sub-bytevector sblock 32 16))
 | ||
| 
 | ||
| (define (btrfs-superblock-volume-name sblock)
 | ||
|   "Return the volume name of btrfs superblock SBLOCK as a string of at most 256
 | ||
| characters, or #f if SBLOCK has no volume name."
 | ||
|   (null-terminated-latin1->string (sub-bytevector sblock 299 256)))
 | ||
| 
 | ||
| (define (check-btrfs-file-system device force? repair)
 | ||
|   "Return the health of an unmounted btrfs file system on DEVICE.  If FORCE? is
 | ||
| false, return 'PASS unconditionally as btrfs claims no need for off-line checks.
 | ||
| When FORCE? is true, do perform a real check.  This is not recommended!  See
 | ||
| @uref{https://bugzilla.redhat.com/show_bug.cgi?id=625967#c8}.  If REPAIR is
 | ||
| false, do not write to DEVICE.  If it's #t, fix any errors found.  Otherwise,
 | ||
| fix only those considered safe to repair automatically."
 | ||
|   (if force?
 | ||
|       (match (status:exit-val
 | ||
|               (apply system*/tty "btrfs" "check" "--progress"
 | ||
|                      ;; Btrfs's ‘--force’ is not relevant to us here.
 | ||
|                      `(,@(match repair
 | ||
|                            ;; Upstream considers ALL repairs dangerous
 | ||
|                            ;; and will warn the user at run time.
 | ||
|                            (#t '("--repair"))
 | ||
|                            (_  '("--readonly"     ; a no-op for clarity
 | ||
|                                  ;; A 466G file system with 180G used is
 | ||
|                                  ;; enough to kill btrfs with 6G of RAM.
 | ||
|                                  "--mode" "lowmem")))
 | ||
|                        ,device)))
 | ||
|         (0 'pass)
 | ||
|         (_ 'fatal-error))
 | ||
|       'pass))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; FAT32 file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; <http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-107.pdf>.
 | ||
| 
 | ||
| (define (fat32-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is a fat32 superblock."
 | ||
|   (bytevector=? (sub-bytevector sblock 82 8)
 | ||
|                 (string->utf8 "FAT32   ")))
 | ||
| 
 | ||
| (define (read-fat32-superblock device)
 | ||
|   "Return the raw contents of DEVICE's fat32 superblock as a bytevector, or
 | ||
| #f if DEVICE does not contain a fat32 file system."
 | ||
|   (read-superblock device 0 90 fat32-superblock?))
 | ||
| 
 | ||
| (define (fat32-superblock-uuid sblock)
 | ||
|   "Return the Volume ID of a fat superblock SBLOCK as a 4-byte bytevector."
 | ||
|   (sub-bytevector sblock 67 4))
 | ||
| 
 | ||
| (define (fat32-superblock-volume-name sblock)
 | ||
|   "Return the volume name of fat superblock SBLOCK as a string of at most 11
 | ||
| characters, or #f if SBLOCK has no volume name.  The volume name is a latin1
 | ||
| string.  Trailing spaces are trimmed."
 | ||
|   (string-trim-right (latin1->string (sub-bytevector sblock 71 11) (lambda (c) #f)) #\space))
 | ||
| 
 | ||
| (define (check-fat-file-system device force? repair)
 | ||
|   "Return the health of an unmounted FAT file system on DEVICE.  FORCE? is
 | ||
| ignored: a full file system scan is always performed.  If REPAIR is false, do
 | ||
| not write to the file system to fix errors. Otherwise, automatically fix them
 | ||
| using the least destructive approach."
 | ||
|   (match (status:exit-val
 | ||
|           (system*/tty "fsck.vfat" "-v"
 | ||
|                        (match repair
 | ||
|                          (#f "-n")
 | ||
|                          (_  "-a"))               ;no 'safe/#t distinction
 | ||
|                        device))
 | ||
|     (0 'pass)
 | ||
|     (1 'errors-corrected)
 | ||
|     (_ 'fatal-error)))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; FAT16 file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| (define (fat16-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is a fat16 boot record."
 | ||
|   (bytevector=? (sub-bytevector sblock 54 8)
 | ||
|                 (string->utf8 "FAT16   ")))
 | ||
| 
 | ||
| (define (read-fat16-superblock device)
 | ||
|   "Return the raw contents of DEVICE's fat16 superblock as a bytevector, or
 | ||
| #f if DEVICE does not contain a fat16 file system."
 | ||
|   (read-superblock device 0 62 fat16-superblock?))
 | ||
| 
 | ||
| (define (fat16-superblock-uuid sblock)
 | ||
|   "Return the Volume ID of a fat superblock SBLOCK as a 4-byte bytevector."
 | ||
|   (sub-bytevector sblock 39 4))
 | ||
| 
 | ||
| (define (fat16-superblock-volume-name sblock)
 | ||
|   "Return the volume name of fat superblock SBLOCK as a string of at most 11
 | ||
| characters, or #f if SBLOCK has no volume name.  The volume name is a latin1
 | ||
| string.  Trailing spaces are trimmed."
 | ||
|   (string-trim-right (latin1->string (sub-bytevector sblock 43 11)
 | ||
|                                      (lambda (c) #f))
 | ||
|                      #\space))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; ISO9660 file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; <http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf>.
 | ||
| 
 | ||
| (define (iso9660-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is an iso9660 volume descriptor."
 | ||
|   (bytevector=? (sub-bytevector sblock 1 6)
 | ||
|                 ;; Note: "\x01" is the volume descriptor format version
 | ||
|                 (string->utf8 "CD001\x01")))
 | ||
| 
 | ||
| (define (read-iso9660-primary-volume-descriptor device offset)
 | ||
|   "Find and read the first primary volume descriptor, starting at OFFSET.
 | ||
|    Return #f if not found."
 | ||
|   (let* ((sblock    (read-superblock device offset 2048 iso9660-superblock?))
 | ||
|          (type-code (if sblock
 | ||
|                         (bytevector-u8-ref sblock 0)
 | ||
|                         (error (format #f
 | ||
|                                        "Could not read ISO9660 primary
 | ||
| volume descriptor from ~s"
 | ||
|                                        device)))))
 | ||
|     (match type-code
 | ||
|       (255 #f) ; Volume Descriptor Set Terminator.
 | ||
|       (1 sblock) ; Primary Volume Descriptor
 | ||
|       (_ (read-iso9660-primary-volume-descriptor device (+ offset 2048))))))
 | ||
| 
 | ||
| (define (read-iso9660-superblock device)
 | ||
|   "Return the raw contents of DEVICE's iso9660 primary volume descriptor
 | ||
| as a bytevector, or #f if DEVICE does not contain an iso9660 file system."
 | ||
|   ;; Start reading at sector 16.
 | ||
|   ;; Since we are not sure that the device contains an ISO9660 file system,
 | ||
|   ;; we have to find that out first.
 | ||
|   (if (read-superblock device (* 2048 16) 2048 iso9660-superblock?)
 | ||
|       (read-iso9660-primary-volume-descriptor device (* 2048 16))
 | ||
|       #f)) ; Device does not contain an iso9660 file system.
 | ||
| 
 | ||
| (define (iso9660-superblock-uuid sblock)
 | ||
|   "Return the modification time of an iso9660 primary volume descriptor
 | ||
| SBLOCK as a bytevector.  If that's not set, returns the creation time."
 | ||
|   ;; Drops GMT offset for compatibility with Grub, blkid and /dev/disk/by-uuid.
 | ||
|   ;; Compare Grub: "2014-12-02-19-30-23-00".
 | ||
|   ;; Compare blkid result: "2014-12-02-19-30-23-00".
 | ||
|   ;; Compare /dev/disk/by-uuid entry: "2014-12-02-19-30-23-00".
 | ||
|   (let* ((creation-time (sub-bytevector sblock 813 17))
 | ||
|          (modification-time (sub-bytevector sblock 830 17))
 | ||
|          (unset-time (make-bytevector 17 0))
 | ||
|          (time (if (bytevector=? unset-time modification-time)
 | ||
|                    creation-time
 | ||
|                    modification-time)))
 | ||
|     (sub-bytevector time 0 16))) ; strips GMT offset.
 | ||
| 
 | ||
| (define (iso9660-superblock-volume-name sblock)
 | ||
|   "Return the volume name of iso9660 superblock SBLOCK as a string.  The volume
 | ||
| name is an ASCII string.  Trailing spaces are trimmed."
 | ||
|   ;; Note: Valid characters are of the set "[0-9][A-Z]_" (ECMA-119 Appendix A)
 | ||
|   (string-trim-right (latin1->string (sub-bytevector sblock 40 32)
 | ||
|                                      (lambda (c) #f)) #\space))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; JFS file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; Taken from <linux-libre>/fs/jfs/jfs_superblock.h.
 | ||
| 
 | ||
| (define-syntax %jfs-endianness
 | ||
|   ;; Endianness of JFS file systems.
 | ||
|   (identifier-syntax (endianness little)))
 | ||
| 
 | ||
| (define (jfs-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is a JFS superblock."
 | ||
|   (bytevector=? (sub-bytevector sblock 0 4)
 | ||
|                 (string->utf8 "JFS1")))
 | ||
| 
 | ||
| (define (read-jfs-superblock device)
 | ||
|   "Return the raw contents of DEVICE's JFS superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain a JFS file system."
 | ||
|   (read-superblock device 32768 184 jfs-superblock?))
 | ||
| 
 | ||
| (define (jfs-superblock-uuid sblock)
 | ||
|   "Return the UUID of JFS superblock SBLOCK as a 16-byte bytevector."
 | ||
|   (sub-bytevector sblock 136 16))
 | ||
| 
 | ||
| (define (jfs-superblock-volume-name sblock)
 | ||
|   "Return the volume name of JFS superblock SBLOCK as a string of at most 16
 | ||
| characters, or #f if SBLOCK has no volume name."
 | ||
|   (null-terminated-latin1->string (sub-bytevector sblock 152 16)))
 | ||
| 
 | ||
| (define (check-jfs-file-system device force? repair)
 | ||
|   "Return the health of an unmounted JFS file system on DEVICE.  If FORCE? is
 | ||
| true, check the file system even if it's marked as clean.  If REPAIR is false,
 | ||
| do not write to the file system to fix errors, and replay the transaction log
 | ||
| only if FORCE?  is true. Otherwise, replay the transaction log before checking
 | ||
| and automatically fix found errors."
 | ||
|   (match (status:exit-val
 | ||
|           (apply system*/tty
 | ||
|                  `("jfs_fsck" "-v"
 | ||
|                    ;; The ‘LEVEL’ logic is convoluted.  To quote fsck/xchkdsk.c
 | ||
|                    ;; (‘-p’, ‘-a’, and ‘-r’ are aliases in every way):
 | ||
|                    ;; “If -f was chosen, have it override [-p] by [forcing] a
 | ||
|                    ;;  check regardless of the outcome after the log is
 | ||
|                    ;;  replayed”.
 | ||
|                    ;; “If -n is specified by itself, don't replay the journal.
 | ||
|                    ;;  If -n is specified with [-p], replay the journal but
 | ||
|                    ;;  don't make any other changes”.
 | ||
|                    ,@(if force? '("-f") '())
 | ||
|                    ,@(match repair
 | ||
|                        (#f '("-n"))
 | ||
|                        (_  '("-p"))) ; no 'safe/#t distinction
 | ||
|                    ,device)))
 | ||
|     (0 'pass)
 | ||
|     (1 'errors-corrected)
 | ||
|     (2 'reboot-required)
 | ||
|     (_ 'fatal-error)))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; F2FS (Flash-Friendly File System)
 | ||
| ;;;
 | ||
| 
 | ||
| ;;; https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/tree/include/linux/f2fs_fs.h
 | ||
| ;;; (but using xxd proved to be simpler)
 | ||
| 
 | ||
| (define-syntax %f2fs-endianness
 | ||
|   ;; Endianness of F2FS file systems
 | ||
|   (identifier-syntax (endianness little)))
 | ||
| 
 | ||
| ;; F2FS actually stores two adjacent copies of the superblock.
 | ||
| ;; should we read both?
 | ||
| (define (f2fs-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is an F2FS superblock."
 | ||
|   (let ((magic (bytevector-u32-ref sblock 0 %f2fs-endianness)))
 | ||
|     (= magic #xF2F52010)))
 | ||
| 
 | ||
| (define (read-f2fs-superblock device)
 | ||
|   "Return the raw contents of DEVICE's F2FS superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain an F2FS file system."
 | ||
|   (read-superblock device
 | ||
|                    ;; offset of magic in first copy
 | ||
|                    #x400
 | ||
|                    ;; difference between magic of second
 | ||
|                    ;; and first copies
 | ||
|                    (- #x1400 #x400)
 | ||
|                    f2fs-superblock?))
 | ||
| 
 | ||
| (define (f2fs-superblock-uuid sblock)
 | ||
|   "Return the UUID of F2FS superblock SBLOCK as a 16-byte bytevector."
 | ||
|   (sub-bytevector sblock
 | ||
|                   (- (+ #x460 12)
 | ||
|                      ;; subtract superblock offset
 | ||
|                      #x400)
 | ||
|                   16))
 | ||
| 
 | ||
| (define (f2fs-superblock-volume-name sblock)
 | ||
|   "Return the volume name of F2FS superblock SBLOCK as a string of at most 512
 | ||
| characters, or #f if SBLOCK has no volume name."
 | ||
|   (null-terminated-utf16->string
 | ||
|    (sub-bytevector sblock (- (+ #x470 12) #x400) 512)
 | ||
|    %f2fs-endianness))
 | ||
| 
 | ||
| (define (check-f2fs-file-system device force? repair)
 | ||
|   "Return the health of an unmuounted F2FS file system on DEVICE.  If FORCE? is
 | ||
| true, check the file system even if it's marked as clean.  If either FORCE? or
 | ||
| REPAIR are true, automatically fix found errors."
 | ||
|   ;; There's no ‘-n’ equivalent (‘--dry-run’ does not disable writes).
 | ||
|   ;; ’-y’ is an alias of ‘-f’.  The man page is bad: read main.c.
 | ||
|   (when (and force? (not repair))
 | ||
|     (format (current-error-port)
 | ||
|             "warning: forced check of F2FS ~a implies repairing any errors~%"
 | ||
|             device))
 | ||
|   (match (status:exit-val
 | ||
|           (apply system*/tty "fsck.f2fs"
 | ||
|                  `(,@(if force? '("-f") '())
 | ||
|                    ,@(if repair '("-p") '("--dry-run"))
 | ||
|                    ,device)))
 | ||
|     ;; 0 and -1 are the only two possibilities according to the man page.
 | ||
|     (0 'pass)
 | ||
|     (_ 'fatal-error)))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; LUKS encrypted devices.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; The LUKS header format is described in "LUKS On-Disk Format Specification":
 | ||
| ;; <https://gitlab.com/cryptsetup/cryptsetup/wikis/Specification>.  We follow
 | ||
| ;; version 1.2.1 of this document.
 | ||
| 
 | ||
| ;; The LUKS2 header format is described in "LUKS2 On-Disk Format Specification":
 | ||
| ;; <https://gitlab.com/cryptsetup/LUKS2-docs/blob/master/luks2_doc_wip.pdf>.
 | ||
| ;; It is a WIP document.
 | ||
| 
 | ||
| (define-syntax %luks-endianness
 | ||
|   ;; Endianness of LUKS headers.
 | ||
|   (identifier-syntax (endianness big)))
 | ||
| 
 | ||
| (define (luks-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is a luks superblock."
 | ||
|   (define %luks-magic
 | ||
|     ;; The 'LUKS_MAGIC' constant.
 | ||
|     (u8-list->bytevector (append (map char->integer (string->list "LUKS"))
 | ||
|                                  (list #xba #xbe))))
 | ||
|   (let ((magic   (sub-bytevector sblock 0 6))
 | ||
|         (version (bytevector-u16-ref sblock 6 %luks-endianness)))
 | ||
|     (and (bytevector=? magic %luks-magic)
 | ||
|          (or (= version 1) (= version 2)))))
 | ||
| 
 | ||
| (define (read-luks-header file)
 | ||
|   "Read a LUKS header from FILE.  Return the raw header on success, and #f if
 | ||
| not valid header was found."
 | ||
|   ;; Size in bytes of the LUKS binary header, which includes key slots in
 | ||
|   ;; LUKS1.  In LUKS2 the binary header is partially backward compatible, so
 | ||
|   ;; that UUID can be extracted as for LUKS1. Keyslots and other metadata are
 | ||
|   ;; not part of this header in LUKS2, but are included in the JSON metadata
 | ||
|   ;; area that follows.
 | ||
|   (read-superblock file 0 592 luks-superblock?))
 | ||
| 
 | ||
| (define (luks-header-uuid header)
 | ||
|   "Return the LUKS UUID from HEADER, as a 16-byte bytevector."
 | ||
|   ;; 40 bytes are reserved for the UUID, but in practice, it contains the 36
 | ||
|   ;; bytes of its ASCII representation.
 | ||
|   (let ((uuid (sub-bytevector header 168 36)))
 | ||
|     (string->uuid (utf8->string uuid))))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; NTFS file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; Taken from <linux-libre>/fs/ntfs/layout.h
 | ||
| 
 | ||
| (define-syntax %ntfs-endianness
 | ||
|   ;; Endianness of NTFS file systems.
 | ||
|   (identifier-syntax (endianness little)))
 | ||
| 
 | ||
| (define (ntfs-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is a NTFS superblock."
 | ||
|   (bytevector=? (sub-bytevector sblock 3 8)
 | ||
|                 (string->utf8 "NTFS    ")))
 | ||
| 
 | ||
| (define (read-ntfs-superblock device)
 | ||
|   "Return the raw contents of DEVICE's NTFS superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain a NTFS file system."
 | ||
|   (read-superblock device 0 511 ntfs-superblock?))
 | ||
| 
 | ||
| (define (ntfs-superblock-uuid sblock)
 | ||
|   "Return the UUID of NTFS superblock SBLOCK as a 8-byte bytevector."
 | ||
|   (sub-bytevector sblock 72 8))
 | ||
| 
 | ||
| ;; TODO: Add ntfs-superblock-volume-name.  The partition label is not stored
 | ||
| ;; in the BOOT SECTOR like the UUID, but in the MASTER FILE TABLE, which seems
 | ||
| ;; way harder to access.
 | ||
| 
 | ||
| (define (check-ntfs-file-system device force? repair)
 | ||
|   "Return the health of an unmounted NTFS file system on DEVICE.  FORCE? is
 | ||
| ignored: a full check is always performed.  Repair is not possible: if REPAIR is
 | ||
| true and the volume has been repaired by an external tool, clear the volume
 | ||
| dirty flag to indicate that it's now safe to mount."
 | ||
|   (match (status:exit-val
 | ||
|           (system*/tty "ntfsfix"
 | ||
|                        (if repair "--clear-dirty" "--no-action")
 | ||
|                        device))
 | ||
|     (0 'pass)
 | ||
|     (_ 'fatal-error)))
 | ||
| 
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; XFS file systems.
 | ||
| ;;;
 | ||
| 
 | ||
| ;; <https://git.kernel.org/pub/scm/fs/xfs/xfs-documentation.git/tree/design/XFS_Filesystem_Structure/allocation_groups.asciidoc>
 | ||
| 
 | ||
| (define-syntax %xfs-endianness
 | ||
|   ;; Endianness of XFS file systems.
 | ||
|   (identifier-syntax (endianness big)))
 | ||
| 
 | ||
| (define (xfs-superblock? sblock)
 | ||
|   "Return #t when SBLOCK is an XFS superblock."
 | ||
|   (bytevector=? (sub-bytevector sblock 0 4)
 | ||
|                 (string->utf8 "XFSB")))
 | ||
| 
 | ||
| (define (read-xfs-superblock device)
 | ||
|   "Return the raw contents of DEVICE's XFS superblock as a bytevector, or #f
 | ||
| if DEVICE does not contain an XFS file system."
 | ||
|   (read-superblock device 0 120 xfs-superblock?))
 | ||
| 
 | ||
| (define (xfs-superblock-uuid sblock)
 | ||
|   "Return the UUID of XFS superblock SBLOCK as a 16-byte bytevector."
 | ||
|   (sub-bytevector sblock 32 16))
 | ||
| 
 | ||
| (define (xfs-superblock-volume-name sblock)
 | ||
|   "Return the volume name of XFS superblock SBLOCK as a string of at most 12
 | ||
| characters, or #f if SBLOCK has no volume name."
 | ||
|   (null-terminated-latin1->string (sub-bytevector sblock 108 12)))
 | ||
| 
 | ||
| (define (check-xfs-file-system device force? repair)
 | ||
|   "Return the health of an unmounted XFS file system on DEVICE.  If FORCE? is
 | ||
| false, return 'PASS unconditionally as XFS claims no need for off-line checks.
 | ||
| When FORCE? is true, do perform a thorough check.  If REPAIR is false, do not
 | ||
| write to DEVICE.  If it's #t, replay the log, check, and fix any errors found.
 | ||
| Otherwise, only replay the log, and check without attempting further repairs."
 | ||
|   (define (xfs_repair)
 | ||
|     (status:exit-val
 | ||
|      (system*/tty "xfs_repair" "-Pv"
 | ||
|                   (match repair
 | ||
|                     (#t "-e")
 | ||
|                     (_  "-n"))                    ;will miss some errors
 | ||
|                   device)))
 | ||
|   (if force?
 | ||
|       ;; xfs_repair fails with exit status 2 if the log is dirty, which is
 | ||
|       ;; likely in situations where you're running xfs_repair.  Only the kernel
 | ||
|       ;; can replay the log by {,un}mounting it cleanly.
 | ||
|       (match (let ((status (xfs_repair)))
 | ||
|                (if (and repair (eq? 2 status))
 | ||
|                    (let ((target "/replay-XFS-log"))
 | ||
|                      ;; The kernel helpfully prints a ‘Mounting…’ notice for us.
 | ||
|                      (mkdir target)
 | ||
|                      (mount device target "xfs")
 | ||
|                      (umount target)
 | ||
|                      (rmdir target)
 | ||
|                      (xfs_repair))
 | ||
|                    status))
 | ||
|         (0 'pass)
 | ||
|         (4 'errors-corrected)
 | ||
|         (_ 'fatal-error))
 | ||
|       'pass))
 | ||
| 
 | ||
| 
 | ||
| ;;;
 | ||
| ;;; Partition lookup.
 | ||
| ;;;
 | ||
| 
 | ||
| (define (disk-partitions)
 | ||
|   "Return the list of device names corresponding to valid disk partitions."
 | ||
|   (define (partition? name major minor)
 | ||
|     ;; grub-mkrescue does some funny things for EFI support which
 | ||
|     ;; makes it a lot more difficult than one would expect to support
 | ||
|     ;; booting an ISO-9660 image from an USB flash drive.
 | ||
|     ;; For example there's a buggy (too small) hidden partition in it
 | ||
|     ;; which Linux mounts and then proceeds to fail while trying to
 | ||
|     ;; fall off the edge.
 | ||
|     ;; In any case, partition tables are supposed to be optional so
 | ||
|     ;; here we allow checking entire disks for file systems, too.
 | ||
|     (> major 2))                      ;ignore RAM disks and floppy disks
 | ||
| 
 | ||
|   (call-with-input-file "/proc/partitions"
 | ||
|     (lambda (port)
 | ||
|       ;; Skip the two header lines.
 | ||
|       (read-line port)
 | ||
|       (read-line port)
 | ||
| 
 | ||
|       ;; Read each subsequent line, and extract the last space-separated
 | ||
|       ;; field.
 | ||
|       (let loop ((parts '()))
 | ||
|         (let ((line  (read-line port)))
 | ||
|           (if (eof-object? line)
 | ||
|               (reverse parts)
 | ||
|               (match (string-tokenize line)
 | ||
|                 (((= string->number major) (= string->number minor)
 | ||
|                   blocks name)
 | ||
|                  (if (partition? name major minor)
 | ||
|                      (loop (cons name parts))
 | ||
|                      (loop parts))))))))))
 | ||
| 
 | ||
| (define (ENOENT-safe proc)
 | ||
|   "Wrap the one-argument PROC such that ENOENT, EIO, and ENOMEDIUM errors are
 | ||
| caught and lead to a warning and #f as the result."
 | ||
|   (lambda (device)
 | ||
|     (catch 'system-error
 | ||
|       (lambda ()
 | ||
|         (proc device))
 | ||
|       (lambda args
 | ||
|         (let ((errno (system-error-errno args)))
 | ||
|           (cond ((= ENOENT errno)
 | ||
|                  (format (current-error-port)
 | ||
|                          "warning: device '~a' not found~%" device)
 | ||
|                  #f)
 | ||
|                 ((= ENOMEDIUM errno)              ;for removable media
 | ||
|                  #f)
 | ||
|                 ((= EIO errno)                    ;unreadable hardware like audio CDs
 | ||
|                  (format (current-error-port)
 | ||
|                          "warning: failed to read from device '~a'~%" device)
 | ||
|                  #f)
 | ||
|                 ((= EMEDIUMTYPE errno)            ;inaccessible, like DRBD secondaries
 | ||
|                  (format (current-error-port)
 | ||
|                          "warning: failed to open device '~a'~%" device)
 | ||
|                  #f)
 | ||
|                 (else
 | ||
|                  (apply throw args))))))))
 | ||
| 
 | ||
| (define (partition-field-reader read field)
 | ||
|   "Return a procedure that takes a device and returns the value of a FIELD in
 | ||
| the partition superblock or #f."
 | ||
|   (lambda (device)
 | ||
|     (let ((sblock (read device)))
 | ||
|       (and sblock
 | ||
|            (field sblock)))))
 | ||
| 
 | ||
| (define (read-partition-field device partition-field-readers)
 | ||
|   "Returns the value of a FIELD in the partition superblock of DEVICE or #f. It
 | ||
| takes a list of PARTITION-FIELD-READERS and returns the result of the first
 | ||
| partition field reader that returned a value."
 | ||
|   (match (filter-map (cut apply <> (list device)) partition-field-readers)
 | ||
|     ((field . _) field)
 | ||
|     (_ #f)))
 | ||
| 
 | ||
| (define %partition-label-readers
 | ||
|   (list (partition-field-reader read-iso9660-superblock
 | ||
|                                 iso9660-superblock-volume-name)
 | ||
|         (partition-field-reader read-ext2-superblock
 | ||
|                                 ext2-superblock-volume-name)
 | ||
|         (partition-field-reader read-linux-swap-superblock
 | ||
|                                 linux-swap-superblock-volume-name)
 | ||
|         (partition-field-reader read-bcachefs-superblock
 | ||
|                                 bcachefs-superblock-volume-name)
 | ||
|         (partition-field-reader read-btrfs-superblock
 | ||
|                                 btrfs-superblock-volume-name)
 | ||
|         (partition-field-reader read-fat32-superblock
 | ||
|                                 fat32-superblock-volume-name)
 | ||
|         (partition-field-reader read-fat16-superblock
 | ||
|                                 fat16-superblock-volume-name)
 | ||
|         (partition-field-reader read-jfs-superblock
 | ||
|                                 jfs-superblock-volume-name)
 | ||
|         (partition-field-reader read-f2fs-superblock
 | ||
|                                 f2fs-superblock-volume-name)
 | ||
|         (partition-field-reader read-xfs-superblock
 | ||
|                                 xfs-superblock-volume-name)))
 | ||
| 
 | ||
| (define %partition-uuid-readers
 | ||
|   (list (partition-field-reader read-iso9660-superblock
 | ||
|                                 iso9660-superblock-uuid)
 | ||
|         (partition-field-reader read-ext2-superblock
 | ||
|                                 ext2-superblock-uuid)
 | ||
|         (partition-field-reader read-linux-swap-superblock
 | ||
|                                 linux-swap-superblock-uuid)
 | ||
|         (partition-field-reader read-bcachefs-superblock
 | ||
|                                 bcachefs-superblock-external-uuid)
 | ||
|         (partition-field-reader read-btrfs-superblock
 | ||
|                                 btrfs-superblock-uuid)
 | ||
|         (partition-field-reader read-fat32-superblock
 | ||
|                                 fat32-superblock-uuid)
 | ||
|         (partition-field-reader read-fat16-superblock
 | ||
|                                 fat16-superblock-uuid)
 | ||
|         (partition-field-reader read-jfs-superblock
 | ||
|                                 jfs-superblock-uuid)
 | ||
|         (partition-field-reader read-f2fs-superblock
 | ||
|                                 f2fs-superblock-uuid)
 | ||
|         (partition-field-reader read-ntfs-superblock
 | ||
|                                 ntfs-superblock-uuid)
 | ||
|         (partition-field-reader read-xfs-superblock
 | ||
|                                 xfs-superblock-uuid)))
 | ||
| 
 | ||
| (define read-partition-label
 | ||
|   (cut read-partition-field <> %partition-label-readers))
 | ||
| 
 | ||
| (define read-partition-uuid
 | ||
|   (cut read-partition-field <> %partition-uuid-readers))
 | ||
| 
 | ||
| (define luks-partition-field-reader
 | ||
|   (partition-field-reader read-luks-header luks-header-uuid))
 | ||
| 
 | ||
| (define read-luks-partition-uuid
 | ||
|   (cut read-partition-field <> (list luks-partition-field-reader)))
 | ||
| 
 | ||
| (define (partition-predicate reader =)
 | ||
|   "Return a predicate that returns true if the FIELD of partition header that
 | ||
| was READ is = to the given value."
 | ||
|   ;; When running on the hand-made /dev, 'disk-partitions' could return
 | ||
|   ;; partitions for which we have no /dev node.  Handle that gracefully.
 | ||
|   (let ((reader (ENOENT-safe reader)))
 | ||
|     (lambda (expected)
 | ||
|       (lambda (device)
 | ||
|         (let ((actual (reader device)))
 | ||
|           (and actual
 | ||
|                (= actual expected)))))))
 | ||
| 
 | ||
| (define partition-label-predicate
 | ||
|   (partition-predicate read-partition-label string=?))
 | ||
| 
 | ||
| (define partition-uuid-predicate
 | ||
|   (partition-predicate read-partition-uuid uuid=?))
 | ||
| 
 | ||
| (define luks-partition-uuid-predicate
 | ||
|   (partition-predicate luks-partition-field-reader uuid=?))
 | ||
| 
 | ||
| (define (find-partition predicate)
 | ||
|   "Return the first partition found that matches PREDICATE, or #f if none
 | ||
| were found."
 | ||
|   (lambda (expected)
 | ||
|     (find (predicate expected)
 | ||
|           (map (cut string-append "/dev/" <>)
 | ||
|                (disk-partitions)))))
 | ||
| 
 | ||
| (define find-partition-by-label
 | ||
|   (find-partition partition-label-predicate))
 | ||
| 
 | ||
| (define find-partition-by-uuid
 | ||
|   (find-partition partition-uuid-predicate))
 | ||
| 
 | ||
| (define find-partition-by-luks-uuid
 | ||
|   (find-partition luks-partition-uuid-predicate))
 | ||
| 
 | ||
| 
 | ||
| (define (canonicalize-device-spec spec)
 | ||
|   "Return the device name corresponding to SPEC, which can be a <uuid>, a
 | ||
| <file-system-label>, the string 'none' or another string (typically a /dev
 | ||
| file name or an nfs-root containing ':/')."
 | ||
|   (define max-trials
 | ||
|     ;; Number of times we retry partition label resolution, 1 second per
 | ||
|     ;; trial.  Note: somebody reported a delay of 16 seconds (!) before their
 | ||
|     ;; USB key would be detected by the kernel, so we must wait for at least
 | ||
|     ;; this long.
 | ||
|     20)
 | ||
| 
 | ||
|   (define (resolve find-partition spec fmt)
 | ||
|     (let loop ((count 0))
 | ||
|       (let ((device (find-partition spec)))
 | ||
|         (or device
 | ||
|             ;; Some devices take a bit of time to appear, most notably USB
 | ||
|             ;; storage devices.  Thus, wait for the device to appear.
 | ||
|             (if (> count max-trials)
 | ||
|                 (error "failed to resolve partition" (fmt spec))
 | ||
|                 (begin
 | ||
|                   (format #t "waiting for partition '~a' to appear...~%"
 | ||
|                           (fmt spec))
 | ||
|                   (sleep 1)
 | ||
|                   (loop (+ 1 count))))))))
 | ||
| 
 | ||
|   (match spec
 | ||
|     ((? string?)
 | ||
|      (if (or (string-contains spec ":/") (string=? spec "none"))
 | ||
|          spec                  ; do not resolve NFS / tmpfs devices
 | ||
|          ;; Nothing to do, but wait until SPEC shows up.
 | ||
|          (resolve identity spec identity)))
 | ||
|     ((? file-system-label?)
 | ||
|      ;; Resolve the label.
 | ||
|      (resolve find-partition-by-label
 | ||
|               (file-system-label->string spec)
 | ||
|               identity))
 | ||
|     ((? uuid?)
 | ||
|      (resolve find-partition-by-uuid
 | ||
|               (uuid-bytevector spec)
 | ||
|               uuid->string))))
 | ||
| 
 | ||
| (define (check-file-system device type force? repair)
 | ||
|   "Check an unmounted TYPE file system on DEVICE.  Do nothing but warn if it is
 | ||
| mounted.  If FORCE? is true, check even when considered unnecessary.  If REPAIR
 | ||
| is false, try not to write to DEVICE at all.  If it's #t, try to fix all errors
 | ||
| found.  Otherwise, fix only those considered safe to repair automatically.  Not
 | ||
| all TYPEs support all values or combinations of FORCE? and REPAIR.  Don't throw
 | ||
| an exception in such cases but perform the nearest sane action."
 | ||
|   (define check-procedure
 | ||
|     (cond
 | ||
|      ((string-prefix? "ext" type) check-ext2-file-system)
 | ||
|      ((string-prefix? "bcachefs" type) check-bcachefs-file-system)
 | ||
|      ((string-prefix? "btrfs" type) check-btrfs-file-system)
 | ||
|      ((string-suffix? "fat" type) check-fat-file-system)
 | ||
|      ((string-prefix? "jfs" type) check-jfs-file-system)
 | ||
|      ((string-prefix? "f2fs" type) check-f2fs-file-system)
 | ||
|      ((string-prefix? "ntfs" type) check-ntfs-file-system)
 | ||
|      ((string-prefix? "nfs" type) (const 'pass))
 | ||
|      ((string-prefix? "xfs" type) check-xfs-file-system)
 | ||
|      (else #f)))
 | ||
| 
 | ||
|   (if check-procedure
 | ||
|       (let ((mount (find (lambda (mount)
 | ||
|                            (string=? device (mount-source mount)))
 | ||
|                          (mounts))))
 | ||
|         (if mount
 | ||
|             (format (current-error-port)
 | ||
|                     "Refusing to check ~a file system already mounted at ~a~%"
 | ||
|                     device (mount-point mount))
 | ||
|             (match (check-procedure device force? repair)
 | ||
|               ('pass
 | ||
|                #t)
 | ||
|               ('errors-corrected
 | ||
|                (format (current-error-port)
 | ||
|                        "File system check corrected errors on ~a; continuing~%"
 | ||
|                        device))
 | ||
|               ('reboot-required
 | ||
|                (format (current-error-port)
 | ||
|                        "File system check corrected errors on ~a; rebooting~%"
 | ||
|                        device)
 | ||
|                (sleep 3)
 | ||
|                (reboot))
 | ||
|               ('fatal-error
 | ||
|                (format (current-error-port) "File system check on ~a failed~%"
 | ||
|                        device)
 | ||
| 
 | ||
|                ;; Spawn a REPL only if someone might interact with it.
 | ||
|                (when (isatty? (current-input-port))
 | ||
|                  (format (current-error-port) "Spawning Bourne-like REPL.~%")
 | ||
| 
 | ||
|                  ;; 'current-output-port' is typically connected to /dev/klog
 | ||
|                  ;; (in PID 1), but here we want to make sure we talk directly
 | ||
|                  ;; to the user.
 | ||
|                  (with-output-to-file "/dev/console"
 | ||
|                    (lambda ()
 | ||
|                      (start-repl %bournish-language))))))))
 | ||
|       (format (current-error-port)
 | ||
|               "No file system check procedure for ~a; skipping~%"
 | ||
|               device)))
 | ||
| 
 | ||
| (define (mount-flags->bit-mask flags)
 | ||
|   "Return the number suitable for the 'flags' argument of 'mount' that
 | ||
| corresponds to the symbols listed in FLAGS."
 | ||
|   (let loop ((flags flags))
 | ||
|     ;; Note: Keep in sync with ‘invalid-file-system-flags’.
 | ||
|     (match flags
 | ||
|       (('read-only rest ...)
 | ||
|        (logior MS_RDONLY (loop rest)))
 | ||
|       (('bind-mount rest ...)
 | ||
|        (logior MS_REC (logior MS_BIND (loop rest))))
 | ||
|       (('no-suid rest ...)
 | ||
|        (logior MS_NOSUID (loop rest)))
 | ||
|       (('no-dev rest ...)
 | ||
|        (logior MS_NODEV (loop rest)))
 | ||
|       (('no-exec rest ...)
 | ||
|        (logior MS_NOEXEC (loop rest)))
 | ||
|       (('no-atime rest ...)
 | ||
|        (logior MS_NOATIME (loop rest)))
 | ||
|       (('no-diratime rest ...)
 | ||
|        (logior MS_NODIRATIME (loop rest)))
 | ||
|       (('strict-atime rest ...)
 | ||
|        (logior MS_STRICTATIME (loop rest)))
 | ||
|       (('lazy-time rest ...)
 | ||
|        (logior MS_LAZYTIME (loop rest)))
 | ||
|       (('shared rest ...)
 | ||
|        (loop rest))
 | ||
|       (()
 | ||
|        0))))
 | ||
| 
 | ||
| (define* (mount-file-system fs #:key (root "/root")
 | ||
|                             (check? (file-system-check? fs))
 | ||
|                             (skip-check-if-clean?
 | ||
|                              (file-system-skip-check-if-clean? fs))
 | ||
|                             (repair (file-system-repair fs)))
 | ||
|   "Mount the file system described by FS, a <file-system> object, under ROOT."
 | ||
| 
 | ||
|   (define (mount-nfs source mount-point type flags options)
 | ||
|     (let* ((idx (string-rindex source #\:))
 | ||
|            (host-part (string-take source idx))
 | ||
|            ;; Strip [] from around host if present
 | ||
|            (host (match (string-split host-part (string->char-set "[]"))
 | ||
|                  (("" h "") h)
 | ||
|                  ((h) h)))
 | ||
|            (aa (match (getaddrinfo host "nfs") ((x . _) x)))
 | ||
|            (sa (addrinfo:addr aa))
 | ||
|            (inet-addr (inet-ntop (sockaddr:fam sa)
 | ||
|                                  (sockaddr:addr sa))))
 | ||
| 
 | ||
|       ;; Mounting an NFS file system requires passing the address
 | ||
|       ;; of the server in the addr= option
 | ||
|       (mount source mount-point type flags
 | ||
|              (string-append "addr="
 | ||
|                             inet-addr
 | ||
|                             (if options
 | ||
|                                 (string-append "," options)
 | ||
|                                 "")))))
 | ||
|   (let* ((type    (file-system-type fs))
 | ||
|          (source  (canonicalize-device-spec (file-system-device fs)))
 | ||
|          (target  (string-append root "/"
 | ||
|                                  (file-system-mount-point fs)))
 | ||
|          (flags   (logior (mount-flags->bit-mask (file-system-flags fs))
 | ||
| 
 | ||
|                           ;; For bind mounts, preserve the original flags such
 | ||
|                           ;; as MS_NOSUID, etc.  Failing to do that, the
 | ||
|                           ;; MS_REMOUNT call below fails with EPERM.
 | ||
|                           ;; See <https://bugs.gnu.org/46292>
 | ||
|                           (if (memq 'bind-mount (file-system-flags fs))
 | ||
|                               (statfs-flags->mount-flags
 | ||
|                                (file-system-mount-flags (statfs source)))
 | ||
|                               0)))
 | ||
|          (options (file-system-options fs)))
 | ||
|     (when check?
 | ||
|       (check-file-system source type (not skip-check-if-clean?) repair))
 | ||
| 
 | ||
|     (catch 'system-error
 | ||
|       (lambda ()
 | ||
|         ;; Create the mount point.  Most of the time this is a directory, but
 | ||
|         ;; in the case of a bind mount, a regular file or socket may be
 | ||
|         ;; needed.
 | ||
|         (if (and (= MS_BIND (logand flags MS_BIND))
 | ||
|                  (not (file-is-directory? source)))
 | ||
|             (unless (file-exists? target)
 | ||
|               (mkdir-p (dirname target))
 | ||
|               (close-fdes
 | ||
|                (open-fdes target (logior O_WRONLY O_CREAT O_CLOEXEC))))
 | ||
|             (mkdir-p target))
 | ||
| 
 | ||
|         (cond
 | ||
|          ((string-prefix? "nfs" type)
 | ||
|           (mount-nfs source target type flags options))
 | ||
|          ((memq 'shared (file-system-flags fs))
 | ||
|           (mount source target type flags options)
 | ||
|           (mount "none" target #f MS_SHARED))
 | ||
|          (else
 | ||
|           (mount source target type flags options)))
 | ||
| 
 | ||
|         ;; For read-only bind mounts, an extra remount is needed, as per
 | ||
|         ;; <http://lwn.net/Articles/281157/>, which still applies to Linux
 | ||
|         ;; 4.0.
 | ||
|         (when (and (= MS_BIND (logand flags MS_BIND))
 | ||
|                    (= MS_RDONLY (logand flags MS_RDONLY)))
 | ||
|           (let ((flags (logior MS_REMOUNT flags)))
 | ||
|             (mount source target type flags options))))
 | ||
|       (lambda args
 | ||
|         (or (file-system-mount-may-fail? fs)
 | ||
|             (apply throw args))))))
 | ||
| 
 | ||
| ;;; file-systems.scm ends here
 |