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file-systems: Add support for bcachefs. 

* gnu/build/file-systems.scm (%bcachefs-endianness): New syntax.
(bcachefs-superblock?, read-bcachefs-superblock)
(bcachefs-superblock-external-uuid, bcachefs-superblock-volume-name)
(check-bcachefs-file-system): New procedures.
(%partition-label-readers, %partition-uuid-readers, check-file-system):
Register them.
master
Tobias Geerinckx-Rice 2020-11-05 13:06:18 +01:00
parent c073efc91c
commit 174254749d
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1 changed files with 58 additions and 1 deletions
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59
gnu/build/file-systems.scm
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@ -3,7 +3,7 @@
;;; 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>
;;;
@ -218,6 +218,58 @@ if DEVICE does not contain an linux-swap file system."
"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)))
;;;
@ -638,6 +690,8 @@ partition field reader that returned a value."
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
@ -656,6 +710,8 @@ partition field reader that returned a value."
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
@ -763,6 +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)