xref: /linux/fs/omfs/omfs_fs.h (revision a1c613ae4c322ddd58d5a8539dbfba2a0380a8c0)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _OMFS_FS_H
3 #define _OMFS_FS_H
4 
5 /* OMFS On-disk structures */
6 
7 #define OMFS_MAGIC 0xC2993D87
8 #define OMFS_IMAGIC 0xD2
9 
10 #define OMFS_DIR 'D'
11 #define OMFS_FILE 'F'
12 #define OMFS_INODE_NORMAL 'e'
13 #define OMFS_INODE_CONTINUATION 'c'
14 #define OMFS_INODE_SYSTEM 's'
15 #define OMFS_NAMELEN 256
16 #define OMFS_DIR_START 0x1b8
17 #define OMFS_EXTENT_START 0x1d0
18 #define OMFS_EXTENT_CONT 0x40
19 #define OMFS_XOR_COUNT 19
20 #define OMFS_MAX_BLOCK_SIZE 8192
21 #define OMFS_MAX_CLUSTER_SIZE 8
22 #define OMFS_MAX_BLOCKS (1ul << 31)
23 
24 struct omfs_super_block {
25 	char s_fill1[256];
26 	__be64 s_root_block;		/* block number of omfs_root_block */
27 	__be64 s_num_blocks;		/* total number of FS blocks */
28 	__be32 s_magic;			/* OMFS_MAGIC */
29 	__be32 s_blocksize;		/* size of a block */
30 	__be32 s_mirrors;		/* # of mirrors of system blocks */
31 	__be32 s_sys_blocksize;		/* size of non-data blocks */
32 };
33 
34 struct omfs_header {
35 	__be64 h_self;			/* FS block where this is located */
36 	__be32 h_body_size;		/* size of useful data after header */
37 	__be16 h_crc;			/* crc-ccitt of body_size bytes */
38 	char h_fill1[2];
39 	u8 h_version;			/* version, always 1 */
40 	char h_type;			/* OMFS_INODE_X */
41 	u8 h_magic;			/* OMFS_IMAGIC */
42 	u8 h_check_xor;			/* XOR of header bytes before this */
43 	__be32 h_fill2;
44 };
45 
46 struct omfs_root_block {
47 	struct omfs_header r_head;	/* header */
48 	__be64 r_fill1;
49 	__be64 r_num_blocks;		/* total number of FS blocks */
50 	__be64 r_root_dir;		/* block # of root directory */
51 	__be64 r_bitmap;		/* block # of free space bitmap */
52 	__be32 r_blocksize;		/* size of a block */
53 	__be32 r_clustersize;		/* size allocated for data blocks */
54 	__be64 r_mirrors;		/* # of mirrors of system blocks */
55 	char r_name[OMFS_NAMELEN];	/* partition label */
56 };
57 
58 struct omfs_inode {
59 	struct omfs_header i_head;	/* header */
60 	__be64 i_parent;		/* parent containing this inode */
61 	__be64 i_sibling;		/* next inode in hash bucket */
62 	__be64 i_ctime;			/* ctime, in milliseconds */
63 	char i_fill1[35];
64 	char i_type;			/* OMFS_[DIR,FILE] */
65 	__be32 i_fill2;
66 	char i_fill3[64];
67 	char i_name[OMFS_NAMELEN];	/* filename */
68 	__be64 i_size;			/* size of file, in bytes */
69 };
70 
71 struct omfs_extent_entry {
72 	__be64 e_cluster;		/* start location of a set of blocks */
73 	__be64 e_blocks;		/* number of blocks after e_cluster */
74 };
75 
76 struct omfs_extent {
77 	__be64 e_next;			/* next extent table location */
78 	__be32 e_extent_count;		/* total # extents in this table */
79 	__be32 e_fill;
80 	struct omfs_extent_entry e_entry[];	/* start of extent entries */
81 };
82 
83 #endif
84