1 typedef struct Super Super;
2 typedef struct Group Group;
3 typedef struct Inode Inode;
4 typedef struct Dirent Dirent;
5 typedef struct Ext2 Ext2;
6 
7 enum
8 {
9 	BYTESPERSEC	= 512,
10 
11 	SBOFF = 1024,
12 	SBSIZE = 1024,
13 
14 	SUPERMAGIC = 0xEF53,
15 	MINBLOCKSIZE = 1024,
16 	MAXBLOCKSIZE = 4096,
17 	ROOTINODE = 2,
18 	FIRSTINODE = 11,
19 	VALIDFS = 0x0001,
20 	ERRORFS = 0x0002,
21 
22 	NDIRBLOCKS = 12,
23 	INDBLOCK = NDIRBLOCKS,
24 	DINDBLOCK = INDBLOCK+1,
25 	TINDBLOCK = DINDBLOCK+1,
26 	NBLOCKS = TINDBLOCK+1,
27 
28 	NAMELEN = 255,
29 
30 	/* permissions in Inode.mode */
31 	IEXEC = 00100,
32 	IWRITE = 0200,
33 	IREAD = 0400,
34 	ISVTX = 01000,
35 	ISGID = 02000,
36 	ISUID = 04000,
37 
38 	/* type in Inode.mode */
39 	IFMT = 0170000,
40 	IFIFO = 0010000,
41 	IFCHR = 0020000,
42 	IFDIR = 0040000,
43 	IFBLK = 0060000,
44 	IFREG = 0100000,
45 	IFLNK = 0120000,
46 	IFSOCK = 0140000,
47 	IFWHT = 0160000,
48 };
49 
50 #define DIRLEN(namlen)	(((namlen)+8+3)&~3)
51 
52 
53 /*
54  * Super block on-disk format.
55  */
56 struct Super
57 {
58 	u32int	ninode;		/* Inodes count */
59 	u32int	nblock;		/* Blocks count */
60 	u32int	rblockcount;	/* Reserved blocks count */
61 	u32int	freeblockcount;	/* Free blocks count */
62 	u32int	freeinodecount;	/* Free inodes count */
63 	u32int	firstdatablock;	/* First Data Block */
64 	u32int	logblocksize;	/* Block size */
65 	u32int	logfragsize;	/* Fragment size */
66 	u32int	blockspergroup;	/* # Blocks per group */
67 	u32int	fragpergroup;	/* # Fragments per group */
68 	u32int	inospergroup;	/* # Inodes per group */
69 	u32int	mtime;		/* Mount time */
70 	u32int	wtime;		/* Write time */
71 	u16int	mntcount;		/* Mount count */
72 	u16int	maxmntcount;	/* Maximal mount count */
73 	u16int	magic;		/* Magic signature */
74 	u16int	state;		/* File system state */
75 	u16int	errors;		/* Behaviour when detecting errors */
76 	u16int	pad;
77 	u32int	lastcheck;		/* time of last check */
78 	u32int	checkinterval;	/* max. time between checks */
79 	u32int	creatoros;		/* OS */
80 	u32int	revlevel;		/* Revision level */
81 	u16int	defresuid;		/* Default uid for reserved blocks */
82 	u16int	defresgid;		/* Default gid for reserved blocks */
83 	u32int	reserved[235];	/* Padding to the end of the block */
84 };
85 
86 /*
87  * Blcok group on-disk format.
88  */
89 struct Group
90 {
91 	u32int	bitblock;		/* Blocks bitmap block */
92 	u32int	inodebitblock;		/* Inodes bitmap block */
93 	u32int	inodeaddr;		/* Inodes table block */
94 	u16int	freeblockscount;	/* Free blocks count */
95 	u16int	freeinodescount;	/* Free inodes count */
96 	u16int	useddirscount;	/* Directories count */
97 	u16int	pad;
98 	u32int	reserved[3];
99 };
100 enum
101 {
102 	GroupSize = 32
103 };
104 
105 /*
106  * Structure of an inode on the disk
107  */
108 struct Inode
109 {
110 	u16int	mode;		/* File mode */
111 	u16int	uid;		/* Owner Uid */
112 	u32int	size;		/* Size in bytes */
113 	u32int	atime;		/* Access time */
114 	u32int	ctime;		/* Creation time */
115 	u32int	mtime;		/* Modification time */
116 	u32int	dtime;		/* Deletion Time */
117 	u16int	gid;		/* Group Id */
118 	u16int	nlink;	/* Links count */
119 	u32int	nblock;	/* Blocks count */
120 	u32int	flags;		/* File flags */
121 	u32int	osd1;				
122 	u32int	block[NBLOCKS];/* Pointers to blocks */
123 	u32int	version;	/* File version (for NFS) */
124 	u32int	fileacl;	/* File ACL */
125 	u32int	diracl;	/* Directory ACL */
126 	u32int	faddr;		/* Fragment address */
127 	uchar	osd2[12];
128 };
129 enum
130 {
131 	InodeSize = 128
132 };
133 
134 /*
135  * Directory entry on-disk structure.
136  */
137 struct Dirent
138 {
139 	u32int	ino;			/* Inode number */
140 	u16int	reclen;		/* Directory entry length */
141 	u8int	namlen;		/* Name length */
142 	u8int	pad;
143 	char	name[NAMELEN];	/* File name */
144 };
145 enum
146 {
147 	MinDirentSize = 4+2+1+1,
148 };
149 
150 /*
151  * In-core fs info.
152  */
153 struct Ext2
154 {
155 	uint	blocksize;
156 	uint	nblock;
157 	uint	ngroup;
158 	uint	inospergroup;
159 	uint	blockspergroup;
160 	uint	inosperblock;
161 	uint	groupaddr;
162 	uint	descperblock;
163 	uint	firstblock;
164 	Disk *disk;
165 	Fsys *fsys;
166 };
167