1 /*
2  * volume_id - reads filesystem label and uuid
3  *
4  * Copyright (C) 2012 S-G Bergh <sgb@systemasis.org>
5  *
6  * Licensed under GPLv2, see file LICENSE in this source tree.
7  */
8 //config:config FEATURE_VOLUMEID_F2FS
9 //config:	bool "f2fs filesystem"
10 //config:	default y
11 //config:	depends on VOLUMEID
12 //config:	help
13 //config:	F2FS (aka Flash-Friendly File System) is a log-structured file system,
14 //config:	which is adapted to newer forms of storage. F2FS also remedies some
15 //config:	known issues of the older log structured file systems, such as high
16 //config:	cleaning overhead.
17 
18 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_F2FS) += f2fs.o
19 
20 #include "volume_id_internal.h"
21 
22 #define F2FS_MAGIC		0xF2F52010	// F2FS Magic Number
23 #define F2FS_UUID_SIZE		16
24 #define F2FS_LABEL_SIZE		512
25 #define F2FS_LABEL_BYTES	1024
26 #define F2FS_SB1_OFFSET		0x400		// offset for 1:st super block
27 /*
28 #define F2FS_SB2_OFFSET		0x1400		// offset for 2:nd super block
29 */
30 
31 struct f2fs_super_block {	// According to version 1.1
32 /* 0x00 */	uint32_t	magic;			// Magic Number
33 /* 0x04 */	uint16_t	major_ver;		// Major Version
34 /* 0x06 */	uint16_t	minor_ver;		// Minor Version
35 /* 0x08 */	uint32_t	log_sectorsize;		// log2 sector size in bytes
36 /* 0x0C */	uint32_t	log_sectors_per_block;	// log2 # of sectors per block
37 /* 0x10 */	uint32_t	log_blocksize;		// log2 block size in bytes
38 /* 0x14 */	uint32_t	log_blocks_per_seg;	// log2 # of blocks per segment
39 /* 0x18 */	uint32_t	segs_per_sec;		// # of segments per section
40 /* 0x1C */	uint32_t	secs_per_zone;		// # of sections per zone
41 /* 0x20 */	uint32_t	checksum_offset;	// checksum offset inside super block
42 /* 0x24 */	uint64_t	block_count;		// total # of user blocks
43 /* 0x2C */	uint32_t	section_count;		// total # of sections
44 /* 0x30 */	uint32_t	segment_count;		// total # of segments
45 /* 0x34 */	uint32_t	segment_count_ckpt;	// # of segments for checkpoint
46 /* 0x38 */	uint32_t	segment_count_sit;	// # of segments for SIT
47 /* 0x3C */	uint32_t	segment_count_nat;	// # of segments for NAT
48 /* 0x40 */	uint32_t	segment_count_ssa;	// # of segments for SSA
49 /* 0x44 */	uint32_t	segment_count_main;	// # of segments for main area
50 /* 0x48 */	uint32_t	segment0_blkaddr;	// start block address of segment 0
51 /* 0x4C */	uint32_t	cp_blkaddr;		// start block address of checkpoint
52 /* 0x50 */	uint32_t	sit_blkaddr;		// start block address of SIT
53 /* 0x54 */	uint32_t	nat_blkaddr;		// start block address of NAT
54 /* 0x58 */	uint32_t	ssa_blkaddr;		// start block address of SSA
55 /* 0x5C */	uint32_t	main_blkaddr;		// start block address of main area
56 /* 0x60 */	uint32_t	root_ino;		// root inode number
57 /* 0x64 */	uint32_t	node_ino;		// node inode number
58 /* 0x68 */	uint32_t	meta_ino;		// meta inode number
59 /* 0x6C */	uint8_t		uuid[F2FS_UUID_SIZE];	// 128-bit uuid for volume
60 /* 0x7C */	uint16_t	volume_name[F2FS_LABEL_SIZE];	// volume name
61 // /* 0x47C */	uint32_t	extension_count;	// # of extensions below
62 // /* 0x480 */	uint8_t		extension_list[64][8];	// extension array
63 } PACKED;
64 
65 
volume_id_probe_f2fs(struct volume_id * id)66 int FAST_FUNC volume_id_probe_f2fs(struct volume_id *id /*,uint64_t off*/)
67 {
68 	struct f2fs_super_block *sb;
69 
70 	// Go for primary super block (ignore second sb)
71 	dbg("f2fs: probing at offset 0x%x", F2FS_SB1_OFFSET);
72 	sb = volume_id_get_buffer(id, F2FS_SB1_OFFSET, sizeof(*sb));
73 
74 	if (!sb)
75 		return -1;
76 
77 	if (sb->magic != cpu_to_le32(F2FS_MAGIC))
78 		return -1;
79 
80 	IF_FEATURE_BLKID_TYPE(id->type = "f2fs");
81 
82 	// For version 1.0 we don't know sb structure and can't set label/uuid
83 	if (sb->major_ver == cpu_to_le16(1) && sb->minor_ver == cpu_to_le16(0))
84 		return 0;
85 
86 	volume_id_set_label_unicode16(id, (uint8_t *)sb->volume_name,
87 				      LE, MIN(F2FS_LABEL_BYTES, VOLUME_ID_LABEL_SIZE));
88 
89 	volume_id_set_uuid(id, sb->uuid, UUID_DCE);
90 
91 	return 0;
92 }
93