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authorZheng Junjie <zhengjunjie@iscas.ac.cn>2024-07-08 20:57:19 +0800
committerZheng Junjie <zhengjunjie@iscas.ac.cn>2024-07-18 10:45:29 +0800
commite9b97b193a9b444399b3cdb33e10906087664b39 (patch)
treebcbb1371e151605dc25928405e77e353e168bbfe /gnu/packages/image.scm
parenta0807675f78bba4889be563dd2823a81c8051a40 (diff)
downloadguix-e9b97b193a9b444399b3cdb33e10906087664b39.tar.gz
guix-e9b97b193a9b444399b3cdb33e10906087664b39.zip
gnu: freeimage: Adjust for libraw 0.21.
* gnu/packages/patches/freeimage-libraw-0.21-compat.patch: New file. * gnu/local.mk (dist_patch_DATA): Add it. * gnu/packages/image.scm (freeimage)[source](patches): Add it. Change-Id: Ief930d50be3e1f44074cd772756fb813bbad4389
Diffstat (limited to 'gnu/packages/image.scm')
-rw-r--r--gnu/packages/image.scm3
1 files changed, 2 insertions, 1 deletions
diff --git a/gnu/packages/image.scm b/gnu/packages/image.scm
index 7d5fc3707e..a709822e5b 100644
--- a/gnu/packages/image.scm
+++ b/gnu/packages/image.scm
@@ -1268,7 +1268,8 @@ supplies a generic doubly-linked list and some string functions.")
(search-patches "freeimage-unbundle.patch"
"freeimage-libtiff-compat.patch"
"freeimage-CVE-2020-21428.patch"
- "freeimage-CVE-2020-22524.patch")
+ "freeimage-CVE-2020-22524.patch"
+ "freeimage-libraw-0.21-compat.patch")
;; Take one patch from Arch Linux that adds LibRaw 0.20 compatibility.
(list (origin
(method url-fetch)
='#n163'>163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
;;; 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>
;;;
;;; 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>, or a 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 (string-contains spec ":/")
         spec                  ; do not resolve NFS 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))
    (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