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01/02: file-systems: Add support for F2FS.
From: |
guix-commits |
Subject: |
01/02: file-systems: Add support for F2FS. |
Date: |
Sat, 2 May 2020 05:02:51 -0400 (EDT) |
dannym pushed a commit to branch master
in repository guix.
commit 23b37c3d40d497cc6f07437ab26ab10e60fb6e09
Author: raingloom <address@hidden>
AuthorDate: Fri Apr 3 02:32:23 2020 +0200
file-systems: Add support for F2FS.
* gnu/build/file-systems.scm (%f2fs-endianness): New syntax.
(f2fs-superblock?, read-f2fs-superblock, f2fs-superblock-uuid)
(f2fs-superblock-volume-name, check-f2fs-file-system): New procedures.
(%partition-label-readers, %partition-uuid-readers, check-file-system):
Register them.
Signed-off-by: Danny Milosavljevic <address@hidden>
---
gnu/build/file-systems.scm | 61 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 59 insertions(+), 2 deletions(-)
diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm
index 902563b..bbea4c7 100644
--- a/gnu/build/file-systems.scm
+++ b/gnu/build/file-systems.scm
@@ -338,6 +338,58 @@ 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."
+ (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 +524,9 @@ 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 +540,9 @@ 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 +638,7 @@ 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)))