1 #ifndef _LINUX_SYSV_FS_H
2 #define _LINUX_SYSV_FS_H
3
4 /*
5 * The SystemV/Coherent filesystem constants/structures/macros
6 */
7
8
9 /* This code assumes
10 - a little endian processor like 386,
11 - sizeof(short) = 2, sizeof(int) = 4, sizeof(long) = 4,
12 - alignof(short) = 2, alignof(long) = 4.
13 */
14
15 #ifdef __GNUC__
16 #define __packed2__ __attribute__ ((packed, aligned(2)))
17 #else
18 #error I want gcc!
19 #endif
20
21 #include <linux/stat.h> /* declares S_IFLNK etc. */
22 #include <linux/sched.h> /* declares wake_up() */
23 #include <linux/sysv_fs_sb.h> /* defines the sv_... shortcuts */
24
25
26 /* Layout on disk */
27 /* ============== */
28
29
30 /* The block size is sb->sv_block_size which may be smaller than BLOCK_SIZE. */
31
32 /* zones (= data allocation units) are blocks */
33
34 /* On Coherent FS, 32 bit quantities are stored using (I quote the Coherent
35 manual) a "canonical byte ordering". This is the PDP-11 byte ordering:
36 x = 2^24 * byte3 + 2^16 * byte2 + 2^8 * byte1 + byte0 is stored
37 as { byte2, byte3, byte0, byte1 }. We need conversions.
38 */
39
40 typedef u32 coh_ulong;
41
42 static inline coh_ulong to_coh_ulong (u32 x)
43 {
44 return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
45 }
46
47 static inline u32 from_coh_ulong (coh_ulong x)
48 {
49 return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
50 }
51
52 /* inode numbers are 16 bit */
53
54 typedef u16 sysv_ino_t;
55
56 /* Block numbers are 24 bit, sometimes stored in 32 bit.
57 On Coherent FS, they are always stored in PDP-11 manner: the least
58 significant 16 bits come last.
59 */
60
61 typedef u32 sysv_zone_t;
62
63 /* Among the blocks ... */
64 /* Xenix FS, Coherent FS: block 0 is the boot block, block 1 the super-block.
65 SystemV FS: block 0 contains both the boot sector and the super-block. */
66 /* The first inode zone is sb->sv_firstinodezone (1 or 2). */
67
68 /* Among the inodes ... */
69 /* 0 is non-existent */
70 #define SYSV_BADBL_INO 1 /* inode of bad blocks file */
71 #define SYSV_ROOT_INO 2 /* inode of root directory */
72
73
74 /* Xenix super-block data on disk */
75 #define XENIX_NICINOD 100 /* number of inode cache entries */
76 #define XENIX_NICFREE 100 /* number of free block list chunk entries */
77 struct xenix_super_block {
78 u16 s_isize; /* index of first data zone */
79 u32 s_fsize __packed2__; /* total number of zones of this fs */
80 /* the start of the free block list: */
81 u16 s_nfree; /* number of free blocks in s_free, <= XENIX_NICFREE */
82 u32 s_free[XENIX_NICFREE]; /* first free block list chunk */
83 /* the cache of free inodes: */
84 u16 s_ninode; /* number of free inodes in s_inode, <= XENIX_NICINOD */
85 sysv_ino_t s_inode[XENIX_NICINOD]; /* some free inodes */
86 /* locks, not used by Linux: */
87 char s_flock; /* lock during free block list manipulation */
88 char s_ilock; /* lock during inode cache manipulation */
89 char s_fmod; /* super-block modified flag */
90 char s_ronly; /* flag whether fs is mounted read-only */
91 u32 s_time __packed2__; /* time of last super block update */
92 u32 s_tfree __packed2__; /* total number of free zones */
93 u16 s_tinode; /* total number of free inodes */
94 s16 s_dinfo[4]; /* device information ?? */
95 char s_fname[6]; /* file system volume name */
96 char s_fpack[6]; /* file system pack name */
97 char s_clean; /* set to 0x46 when filesystem is properly unmounted */
98 char s_fill[371];
99 s32 s_magic; /* version of file system */
100 s32 s_type; /* type of file system: 1 for 512 byte blocks
101 2 for 1024 byte blocks
102 3 for 2048 byte blocks */
103
104 };
105
106 /* Xenix free list block on disk */
107 struct xenix_freelist_chunk {
108 u16 fl_nfree; /* number of free blocks in fl_free, <= XENIX_NICFREE] */
109 u32 fl_free[XENIX_NICFREE] __packed2__;
110 };
111
112 /* SystemV FS comes in two variants:
113 * sysv2: System V Release 2 (e.g. Microport), structure elements aligned(2).
114 * sysv4: System V Release 4 (e.g. Consensys), structure elements aligned(4).
115 */
116 #define SYSV_NICINOD 100 /* number of inode cache entries */
117 #define SYSV_NICFREE 50 /* number of free block list chunk entries */
118
119 /* SystemV4 super-block data on disk */
120 struct sysv4_super_block {
121 u16 s_isize; /* index of first data zone */
122 u16 s_pad0;
123 u32 s_fsize; /* total number of zones of this fs */
124 /* the start of the free block list: */
125 u16 s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
126 u16 s_pad1;
127 u32 s_free[SYSV_NICFREE]; /* first free block list chunk */
128 /* the cache of free inodes: */
129 u16 s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
130 u16 s_pad2;
131 sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
132 /* locks, not used by Linux: */
133 char s_flock; /* lock during free block list manipulation */
134 char s_ilock; /* lock during inode cache manipulation */
135 char s_fmod; /* super-block modified flag */
136 char s_ronly; /* flag whether fs is mounted read-only */
137 u32 s_time; /* time of last super block update */
138 s16 s_dinfo[4]; /* device information ?? */
139 u32 s_tfree; /* total number of free zones */
140 u16 s_tinode; /* total number of free inodes */
141 u16 s_pad3;
142 char s_fname[6]; /* file system volume name */
143 char s_fpack[6]; /* file system pack name */
144 s32 s_fill[12];
145 s32 s_state; /* file system state: 0x7c269d38-s_time means clean */
146 s32 s_magic; /* version of file system */
147 s32 s_type; /* type of file system: 1 for 512 byte blocks
148 2 for 1024 byte blocks */
149 };
150
151 /* SystemV4 free list block on disk */
152 struct sysv4_freelist_chunk {
153 u16 fl_nfree; /* number of free blocks in fl_free, <= SYSV_NICFREE] */
154 u32 fl_free[SYSV_NICFREE];
155 };
156
157 /* SystemV2 super-block data on disk */
158 struct sysv2_super_block {
159 u16 s_isize; /* index of first data zone */
160 u32 s_fsize __packed2__; /* total number of zones of this fs */
161 /* the start of the free block list: */
162 u16 s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
163 u32 s_free[SYSV_NICFREE]; /* first free block list chunk */
164 /* the cache of free inodes: */
165 u16 s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
166 sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
167 /* locks, not used by Linux: */
168 char s_flock; /* lock during free block list manipulation */
169 char s_ilock; /* lock during inode cache manipulation */
170 char s_fmod; /* super-block modified flag */
171 char s_ronly; /* flag whether fs is mounted read-only */
172 u32 s_time __packed2__; /* time of last super block update */
173 s16 s_dinfo[4]; /* device information ?? */
174 u32 s_tfree __packed2__; /* total number of free zones */
175 u16 s_tinode; /* total number of free inodes */
176 char s_fname[6]; /* file system volume name */
177 char s_fpack[6]; /* file system pack name */
178 s32 s_fill[14];
179 s32 s_state; /* file system state: 0xcb096f43 means clean */
180 s32 s_magic; /* version of file system */
181 s32 s_type; /* type of file system: 1 for 512 byte blocks
182 2 for 1024 byte blocks */
183 };
184
185 /* SystemV2 free list block on disk */
186 struct sysv2_freelist_chunk {
187 u16 fl_nfree; /* number of free blocks in fl_free, <= SYSV_NICFREE] */
188 u32 fl_free[SYSV_NICFREE] __packed2__;
189 };
190
191 /* Coherent super-block data on disk */
192 #define COH_NICINOD 100 /* number of inode cache entries */
193 #define COH_NICFREE 64 /* number of free block list chunk entries */
194 struct coh_super_block {
195 u16 s_isize; /* index of first data zone */
196 coh_ulong s_fsize __packed2__; /* total number of zones of this fs */
197 /* the start of the free block list: */
198 u16 s_nfree; /* number of free blocks in s_free, <= COH_NICFREE */
199 coh_ulong s_free[COH_NICFREE] __packed2__; /* first free block list chunk */
200 /* the cache of free inodes: */
201 u16 s_ninode; /* number of free inodes in s_inode, <= COH_NICINOD */
202 sysv_ino_t s_inode[COH_NICINOD]; /* some free inodes */
203 /* locks, not used by Linux: */
204 char s_flock; /* lock during free block list manipulation */
205 char s_ilock; /* lock during inode cache manipulation */
206 char s_fmod; /* super-block modified flag */
207 char s_ronly; /* flag whether fs is mounted read-only */
208 coh_ulong s_time __packed2__; /* time of last super block update */
209 coh_ulong s_tfree __packed2__; /* total number of free zones */
210 u16 s_tinode; /* total number of free inodes */
211 u16 s_interleave_m; /* interleave factor */
212 u16 s_interleave_n;
213 char s_fname[6]; /* file system volume name */
214 char s_fpack[6]; /* file system pack name */
215 u32 s_unique; /* zero, not used */
216 };
217
218 /* Coherent free list block on disk */
219 struct coh_freelist_chunk {
220 u16 fl_nfree; /* number of free blocks in fl_free, <= COH_NICFREE] */
221 u32 fl_free[COH_NICFREE] __packed2__;
222 };
223
224
225 /* SystemV/Coherent inode data on disk */
226
227 struct sysv_inode {
228 u16 i_mode;
229 u16 i_nlink;
230 u16 i_uid;
231 u16 i_gid;
232 u32 i_size;
233 union { /* directories, regular files, ... */
234 unsigned char i_addb[3*(10+1+1+1)+1]; /* zone numbers: max. 10 data blocks,
235 * then 1 indirection block,
236 * then 1 double indirection block,
237 * then 1 triple indirection block.
238 * Then maybe a "file generation number" ??
239 */
240 /* devices */
241 dev_t i_rdev;
242 /* named pipes on Coherent */
243 struct {
244 char p_addp[30];
245 s16 p_pnc;
246 s16 p_prx;
247 s16 p_pwx;
248 } i_p;
249 } i_a;
250 u32 i_atime; /* time of last access */
251 u32 i_mtime; /* time of last modification */
252 u32 i_ctime; /* time of creation */
253 };
254
255 /* The admissible values for i_mode are listed in <linux/stat.h> :
256 * #define S_IFMT 00170000 mask for type
257 * #define S_IFREG 0100000 type = regular file
258 * #define S_IFBLK 0060000 type = block device
259 * #define S_IFDIR 0040000 type = directory
260 * #define S_IFCHR 0020000 type = character device
261 * #define S_IFIFO 0010000 type = named pipe
262 * #define S_ISUID 0004000 set user id
263 * #define S_ISGID 0002000 set group id
264 * #define S_ISVTX 0001000 save swapped text even after use
265 * Additionally for SystemV:
266 * #define S_IFLNK 0120000 type = symbolic link
267 * #define S_IFNAM 0050000 type = XENIX special named file ??
268 * Additionally for Coherent:
269 * #define S_IFMPB 0070000 type = multiplexed block device ??
270 * #define S_IFMPC 0030000 type = multiplexed character device ??
271 *
272 * Since Coherent doesn't know about symbolic links, we use a kludgey
273 * implementation of symbolic links: i_mode = COH_KLUDGE_SYMLINK_MODE
274 * denotes a symbolic link. When a regular file should get this mode by
275 * accident, it is automatically converted to COH_KLUDGE_NOT_SYMLINK.
276 * We use S_IFREG because only regular files (and Coherent pipes...) can have
277 * data blocks with arbitrary contents associated with them, and S_ISVTX
278 * ("save swapped text after use") because it is unused on both Linux and
279 * Coherent: Linux does much more intelligent paging, and Coherent hasn't
280 * virtual memory at all.
281 * Same trick for Xenix.
282 */
283 #define COH_KLUDGE_SYMLINK_MODE (S_IFREG | S_ISVTX)
284 #define COH_KLUDGE_NOT_SYMLINK (S_IFREG | S_ISVTX | S_IRUSR) /* force read access */
285 extern inline mode_t from_coh_imode(unsigned short mode)
286 {
287 if (mode == COH_KLUDGE_SYMLINK_MODE)
288 return (S_IFLNK | 0777);
289 else
290 return mode;
291 }
292 extern inline unsigned short to_coh_imode(mode_t mode)
293 {
294 if (S_ISLNK(mode))
295 return COH_KLUDGE_SYMLINK_MODE;
296 else if (mode == COH_KLUDGE_SYMLINK_MODE)
297 return COH_KLUDGE_NOT_SYMLINK;
298 else
299 return mode;
300 }
301
302 /* Admissible values for i_nlink: 0.._LINK_MAX */
303 #define XENIX_LINK_MAX 126 /* ?? */
304 #define SYSV_LINK_MAX 126 /* 127? 251? */
305 #define COH_LINK_MAX 10000 /* max number of hard links to an inode */
306
307 /* The number of inodes per block is
308 sb->sv_inodes_per_block = block_size / sizeof(struct sysv_inode) */
309 /* The number of indirect pointers per block is
310 sb->sv_ind_per_block = block_size / sizeof(u32) */
311
312
313 /* SystemV/Coherent directory entry on disk */
314
315 #define SYSV_NAMELEN 14 /* max size of name in struct sysv_dir_entry */
316
317 struct sysv_dir_entry {
318 sysv_ino_t inode;
319 char name[SYSV_NAMELEN]; /* up to 14 characters, the rest are zeroes */
320 };
321
322 #define SYSV_DIRSIZE sizeof(struct sysv_dir_entry) /* size of every directory entry */
323
324
325 /* Operations */
326 /* ========== */
327
328
329 /* identify the FS in memory */
330 #define FSTYPE_XENIX 1
331 #define FSTYPE_SYSV4 2
332 #define FSTYPE_SYSV2 3
333 #define FSTYPE_COH 4
334
335 #define SYSV_MAGIC_BASE 0x012FF7B3
336
337 #define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_XENIX)
338 #define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
339 #define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
340 #define COH_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_COH)
341
342 #ifdef __KERNEL__
343
344 /* sv_get_hash_table(sb,dev,block) is equivalent to get_hash_table(dev,block,block_size) */
345 static inline struct buffer_head *
346 sv_get_hash_table (struct super_block *sb, kdev_t dev, unsigned int block)
347 {
348 return get_hash_table (dev, block + sb->sv_block_base, sb->sv_block_size);
349 }
350
351 /* sv_getblk(sb,dev,block) is equivalent to getblk(dev,block,block_size) */
352 static inline struct buffer_head *
353 sv_getblk (struct super_block *sb, kdev_t dev, unsigned int block)
354 {
355 return getblk (dev, block + sb->sv_block_base, sb->sv_block_size);
356 }
357
358 /* sv_bread(sb,dev,block) is equivalent to bread(dev,block,block_size) */
359 static inline struct buffer_head *
360 sv_bread (struct super_block *sb, kdev_t dev, unsigned int block)
361 {
362 return bread (dev, block + sb->sv_block_base, sb->sv_block_size);
363 }
364
365
366 /*
367 * Function prototypes
368 */
369
370 extern struct inode * sysv_new_inode(const struct inode * dir);
371 extern void sysv_free_inode(struct inode * inode);
372 extern unsigned long sysv_count_free_inodes(struct super_block *sb);
373 extern int sysv_new_block(struct super_block * sb);
374 extern void sysv_free_block(struct super_block * sb, unsigned int block);
375 extern unsigned long sysv_count_free_blocks(struct super_block *sb);
376
377 extern struct buffer_head * sysv_file_bread(struct inode *, int, int);
378
379 extern void sysv_truncate(struct inode *);
380 extern void sysv_write_inode(struct inode *, int);
381 extern int sysv_sync_inode(struct inode *);
382 extern int sysv_sync_file(struct file *, struct dentry *, int);
383 extern int sysv_notify_change(struct dentry *, struct iattr *);
384
385 extern struct inode_operations sysv_file_inode_operations;
386 extern struct inode_operations sysv_symlink_inode_operations;
387 extern struct inode_operations sysv_dir_inode_operations;
388 extern struct file_operations sysv_file_operations;
389 extern struct file_operations sysv_dir_operations;
390 extern struct address_space_operations sysv_aops;
391
392 #endif /* __KERNEL__ */
393
394 #endif
395
396
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