1 /*
2  * An FFS file system is a sequence of cylinder groups.
3  *
4  * Each cylinder group is laid out as follows:
5  *
6  *	fs superblock (Fsblk)
7  *	cylinder group block (Cgblk)
8  *	inodes
9  *	data
10  *
11  * The location of the fs superblock in the first cylinder
12  * group is known.  The rest of the info about cylinder group
13  * layout can be derived from the super block.
14  */
15 
16 #define daddr_t u32int
17 #define time_t u32int
18 
19 typedef struct Cgblk Cgblk;
20 typedef struct Cylgrp Cylgrp;
21 typedef struct Cylsum Cylsum;
22 typedef struct Cylsumtotal Cylsumtotal;
23 typedef struct Ffs Ffs;
24 typedef struct Fsblk Fsblk;
25 typedef struct Inode1 Inode1;
26 typedef struct Inode Inode;
27 typedef struct Dirent Dirent;
28 
29 enum
30 {
31 	BYTESPERSEC = 512,
32 
33 	/* constants for Fsblk */
34 	FSMAXMNTLEN = 512,
35 	FSMAXMNTLEN2 = 468,
36 	FSMAXVOLLEN = 32,				/* UFS2 */
37 	FSNOCSPTRSLEN = 128-12,
38 	FSNOCSPTRSLEN2 = 128-16,	/* UFS2 */
39 	FSMAXSNAP = 20,
40 	FSMAGIC = 0x011954,
41 	FSMAGIC2 = 0x19540119,
42 	FSCHECKSUM = 0x7c269d38,
43 	
44 	/* Fsblk.inodefmt */
45 	FS42INODEFMT = -1,
46 	FS44INODEFMT = 2,
47 
48 	/* offset and size of first boot block */
49 	BBOFF = 0,
50 	BBSIZE = 8192,
51 
52 	/* offset and size of first super block */
53 	SBOFF = BBOFF+BBSIZE,
54 	SBOFF2 = BBOFF+65536,			/* UFS2 */
55 	SBOFFPIGGY = BBOFF+262144,		/* UFS2 */
56 	SBSIZE = 8192,
57 
58 	/* minimum block size */
59 	MINBSIZE = 4096,
60 
61 	/* maximum fragments per block */
62 	MAXFRAG = 8,
63 
64 	/* constants for Cgblk */
65 	CGMAGIC = 0x090255,
66 
67 	/* inode-related */
68 	ROOTINODE = 2,
69 	WHITEOUT = 1,
70 
71 	NXADDR = 2,	/* UFS2 */
72 	NDADDR = 12,
73 	NIADDR = 3,
74 
75 	/* permissions in Inode.mode */
76 	IEXEC = 00100,
77 	IWRITE = 0200,
78 	IREAD = 0400,
79 	ISVTX = 01000,
80 	ISGID = 02000,
81 	ISUID = 04000,
82 
83 	/* type in Inode.mode */
84 	IFMT = 0170000,
85 	IFIFO = 0010000,
86 	IFCHR = 0020000,
87 	IFDIR = 0040000,
88 	IFBLK = 0060000,
89 	IFREG = 0100000,
90 	IFLNK = 0120000,
91 	IFSOCK = 0140000,
92 	IFWHT = 0160000,
93 
94 	/* type in Dirent.type */
95 	DTUNKNOWN = 0,
96 	DTFIFO = 1,
97 	DTCHR = 2,
98 	DTDIR = 4,
99 	DTBLK = 6,
100 	DTREG = 8,
101 	DTLNK = 10,
102 	DTSOCK = 12,
103 	DTWHT = 14
104 };
105 
106 struct Cylsum
107 {
108 	u32int	ndir;
109 	u32int	nbfree;
110 	u32int	nifree;
111 	u32int	nffree;
112 };
113 
114 struct Cylsumtotal
115 {
116 	u64int	ndir;
117 	u64int	nbfree;
118 	u64int	nifree;
119 	u64int	nffree;
120 	u64int	numclusters;
121 	u64int	unused[3];
122 };
123 
124 /* Fields beginning with underscore are deprecated in UFS2 */
125 struct Fsblk
126 {
127 	u32int	unused0;
128 	u32int	unused1;
129 	daddr_t	sfragno;		/* fragment address of super block in file system */
130 	daddr_t	cfragno;		/* fragment address if cylinder block in file system */
131 	daddr_t	ifragno;		/* fragment offset of inode blocks in file system */
132 	daddr_t	dfragno;		/* fragment offset of data blocks in cg */
133 	u32int	_cgoffset;		/* block (maybe fragment?) offset of Cgblk in cylinder */
134 	u32int	_cgmask;
135 	time_t	_time;
136 	u32int	_nfrag;			/* number of blocks in fs * fragsperblock */
137 	u32int	_ndfrag;
138 	u32int	ncg;			/* number of cylinder groups in fs */
139 	u32int	blocksize;		/* block size in fs */
140 	u32int	fragsize;		/* frag size in fs */
141 	u32int	fragsperblock;	/* fragments per block: blocksize / fragsize */
142 	u32int	minfree;		/* ignored by us */
143 	u32int	rotdelay;		/* ... */
144 	u32int	rps;
145 	u32int	bmask;
146 	u32int	fmask;
147 	u32int	bshift;
148 	u32int	fshift;
149 	u32int	maxcontig;
150 	u32int	maxbpg;
151 	u32int	fragshift;
152 	u32int	fsbtodbshift;
153 	u32int	sbsize;			/* size of super block */
154 	u32int	unused2;		/* more stuff we don't use ... */
155 	u32int	unused3;
156 	u32int	nindir;
157 	u32int	inosperblock;	/* inodes per block */
158 	u32int	_nspf;
159 	u32int	optim;
160 	u32int	_npsect;
161 	u32int	_interleave;
162 	u32int	_trackskew;
163 	u32int	id[2];
164 	daddr_t	_csaddr;		/* blk addr of cyl grp summary area */
165 	u32int	cssize;			/* size of cyl grp summary area */
166 	u32int	cgsize;			/* cylinder group size */
167 	u32int	_trackspercyl;	/* tracks per cylinder */
168 	u32int	_secspertrack;	/* sectors per track */
169 	u32int	_secspercyl;	/* sectors per cylinder */
170 	u32int	_ncyl;			/* cylinders in fs */
171 	u32int	_cylspergroup;	/* cylinders per group */
172 	u32int	inospergroup;	/* inodes per group */
173 	u32int	fragspergroup;	/* data blocks per group * fragperblock */
174 	Cylsum	_cstotal;		/* more unused... */
175 	u8int	fmod;
176 	u8int	clean;
177 	u8int	ronly;
178 	u8int	_flags;
179 	/* char fsmnt[512]; in UFS1 */
180 		char	fsmnt[FSMAXMNTLEN2];
181 		char	volname[FSMAXVOLLEN];
182 		u64int	swuid;
183 		u32int	pad;
184 	u32int	cgrotor;
185 	uchar	ocsp[FSNOCSPTRSLEN]; /* last 4 bytes is contigdirs in UFS2 */
186 	u32int	contigdirs;		/* csp in UFS2 */
187 	u32int	csp;			/* maxcluster in UFS2 */
188 	u32int	maxcluster;		/* active in UFS2 */
189 	u32int	_cpc;
190 	/* u16int	opostbl[16][8]; in UFS1 */
191 		u32int	maxbsize;
192 		u64int	spare64[17];
193 		u64int	sblockloc;
194 		Cylsumtotal	cstotal;
195 		u64int	time;
196 		u64int	nfrag;
197 		u64int	ndfrag;
198 		u64int	csaddr;
199 		u64int	pendingblocks;
200 		u32int	pendinginodes;
201 	u32int	snapinum[FSMAXSNAP];
202 	u32int	avgfilesize;
203 	u32int	avgfpdir;
204 	/* u32int sparecon[26], pendingblocks, pendinginodes; in UFS1 */
205 		u32int	savecgsize;
206 		u32int	sparecon[26];
207 		u32int	flags;
208 	u32int	contigsumsize;
209 	u32int	maxsymlinklen;
210 	u32int	_inodefmt;		/* format of on-disk inodes */
211 	u64int	maxfilesize;	/* maximum representable file size */
212 	u64int	qbmask;
213 	u64int	qfmask;
214 	u32int	state;
215 	u32int	_postblformat;
216 	u32int	_nrpos;
217 	u32int	_postbloff;
218 	u32int	_rotbloff;
219 	u32int	magic;			/* FSMAGIC or FSMAGIC2 */
220 };
221 
222 /*
223  * Cylinder group block for a file system.
224  */
225 struct Cgblk
226 {
227 	u32int	unused0;
228 	u32int	magic;			/* CGMAGIC */
229 	u32int	time;			/* time last written */
230 	u32int	num;			/* we are cg #cgnum */
231 	u16int	ncyl;			/* number of cylinders in gp */
232 	u16int	nino;			/* number of inodes */
233 	u32int	nfrag;			/* number of fragments  */
234 	Cylsum	csum;
235 	u32int	rotor;
236 	u32int	frotor;
237 	u32int	irotor;
238 	u32int	frsum[MAXFRAG];	/* counts of available frags */
239 	u32int	btotoff;
240 	u32int	boff;
241 	u32int	imapoff;		/* offset to used inode map */
242 	u32int	fmapoff;		/* offset to free fragment map */
243 	u32int	nextfrag;		/* next free fragment */
244 	u32int	csumoff;
245 	u32int	clusteroff;
246 	u32int	ncluster;
247 	u32int	sparecon[13];
248 };
249 
250 struct Cylgrp
251 {
252 	/* these are block numbers not fragment numbers */
253 	u64int	bno;			/* disk block address of start of cg */
254 	u64int	ibno;			/* disk block address of first inode */
255 	u64int	dbno;			/* disk block address of first data */
256 	u64int	cgblkno;
257 };
258 
259 /*
260  * this is the on-disk structure
261  */
262 struct Inode1
263 {
264 	u16int	mode;
265 	u16int	nlink;
266 	u32int	unused;
267 	u64int	size;
268 	u32int	atime;
269 	u32int	atimensec;
270 	u32int	mtime;
271 	u32int	mtimensec;
272 	u32int	ctime;
273 	u32int	ctimensec;
274 	/* rdev is db[0] */
275 	u32int	db[NDADDR];
276 	u32int	ib[NIADDR];
277 	u32int	flags;
278 	u32int	nblock;
279 	u32int	gen;
280 	u32int	uid;
281 	u32int	gid;
282 	u32int	spare[2];
283 };
284 
285 struct Inode
286 {
287 	u16int	mode;
288 	u16int	nlink;
289 	u32int	uid;
290 	u32int	gid;
291 	u32int	blksize;
292 	u64int	size;
293 	u64int	nblock;
294 	u64int	atime;
295 	u64int	mtime;
296 	u64int	ctime;
297 	u64int	btime;
298 	u32int	atimensec;
299 	u32int	mtimensec;
300 	u32int	ctimensec;
301 	u32int	btimensec;
302 	u32int	gen;
303 	u32int	kernflags;
304 	u32int	flags;
305 	u32int	extsize;
306 	u64int	ext[NXADDR];
307 	u64int	db[NDADDR];
308 	u64int	ib[NIADDR];
309 	u64int	spare[3];
310 };
311 
312 struct Dirent
313 {
314 	u32int	ino;
315 	u16int	reclen;
316 	u8int	type;
317 	u8int	namlen;
318 	char		name[1];
319 };
320 
321 /*
322  * main file system structure
323  */
324 struct Ffs
325 {
326 	int		ufs;
327 	int		blocksize;
328 	u64int	nblock;
329 	int		fragsize;
330 	int		fragsperblock;
331 	int		inosperblock;
332 	u64int	blockspergroup;
333 	u64int	fragspergroup;
334 	int		inospergroup;
335 
336 	u64int	nfrag;
337 	u64int	ndfrag;
338 
339 	int		ncg;
340 	Cylgrp	*cg;
341 
342 	Disk		*disk;
343 };
344