diff options
Diffstat (limited to 'gnu/build/file-systems.scm')
| -rw-r--r-- | gnu/build/file-systems.scm | 105 |
1 files changed, 103 insertions, 2 deletions
diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm index 734d648575..b762e82ad2 100644 --- a/gnu/build/file-systems.scm +++ b/gnu/build/file-systems.scm @@ -1,9 +1,9 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2014, 2015, 2016, 2017, 2018, 2020 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 Tobias Geerinckx-Rice <me@tobias.gr> +;;; Copyright © 2019, 2020 Tobias Geerinckx-Rice <me@tobias.gr> ;;; Copyright © 2019 David C. Trudgian <dave@trudgian.net> ;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com> ;;; @@ -181,6 +181,98 @@ if DEVICE does not contain an ext2 file system." ;;; +;;; 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))) + + +;;; +;;; 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." + ;; We completely ignore the back-up superblock & any checksum errors. + ;; Superblock field names, with offset & length respectively, in bytes: + ;; 0 16 bch_csum + ;; 16 8 version + ;; 24 16 magic + ;; 40 16 uuid ← ‘internal UUID’, you probably don't want this + ;; 56 16 user_uuid ← ‘external UUID’, the one by which to mount + ;; 72 32 label + ;; … there are more & the superblock is extensible, but we don't care yet. + (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 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) + "Return the health of a bcachefs file system on DEVICE." + (match (status:exit-val + (apply system* "bcachefs" "fsck" "-p" "-v" + ;; Make each multi-device member a separate argument. + (string-split device #\:))) + (0 'pass) + (1 'errors-corrected) + (2 'reboot-required) + (_ 'fatal-error))) + + +;;; ;;; Btrfs file systems. ;;; @@ -596,6 +688,10 @@ partition field reader that returned a value." 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 @@ -612,6 +708,10 @@ partition field reader that returned a value." 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 @@ -719,6 +819,7 @@ containing ':/')." (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) |