diff options
Diffstat (limited to 'gnu/build/file-systems.scm')
| -rw-r--r-- | gnu/build/file-systems.scm | 104 |
1 files changed, 102 insertions, 2 deletions
diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm index 902563b219..b920e8fc62 100644 --- a/gnu/build/file-systems.scm +++ b/gnu/build/file-systems.scm @@ -98,6 +98,47 @@ takes a bytevector and returns #t when it's a valid superblock." (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. @@ -338,6 +379,60 @@ if DEVICE does not contain a JFS file system." ;;; +;;; 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 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) + "Return the health of a F2FS file system on DEVICE." + (match (status:exit-val + (system* "fsck.f2fs" "-p" device)) + ;; 0 and -1 are the only two possibilities + ;; (according to the manpage) + (0 'pass) + (_ 'fatal-error))) + + +;;; ;;; LUKS encrypted devices. ;;; @@ -472,7 +567,9 @@ partition field reader that returned a value." (partition-field-reader read-fat16-superblock fat16-superblock-volume-name) (partition-field-reader read-jfs-superblock - jfs-superblock-volume-name))) + jfs-superblock-volume-name) + (partition-field-reader read-f2fs-superblock + f2fs-superblock-volume-name))) (define %partition-uuid-readers (list (partition-field-reader read-iso9660-superblock @@ -486,7 +583,9 @@ partition field reader that returned a value." (partition-field-reader read-fat16-superblock fat16-superblock-uuid) (partition-field-reader read-jfs-superblock - jfs-superblock-uuid))) + jfs-superblock-uuid) + (partition-field-reader read-f2fs-superblock + f2fs-superblock-uuid))) (define read-partition-label (cut read-partition-field <> %partition-label-readers)) @@ -582,6 +681,7 @@ were found." ((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? "nfs" type) (const 'pass)) (else #f))) |