![[first]](../icons/first.png){kind=icon}
![[previous]](../icons/n_left.png){kind=icon}
![[next]](../icons/n_right.png){kind=icon}
![[last]](../icons/last.png){kind=icon}
![[top]](../icons/n_top.png){kind=icon}
![[bottom]](../icons/bottom.png){kind=icon}
![[index]](../icons/index.png){kind=icon}
![[help]](../icons/help.png){kind=icon}
*/
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 unsigned long coh_ulong;
41
42 static inline coh_ulong to_coh_ulong (unsigned long x)
/* ![[next]](../icons/right.png)
![[first]](../icons/n_first.png)
![[top]](../icons/top.png)
*/
43 {
44 return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
45 }
46
47 static inline unsigned long from_coh_ulong (coh_ulong x)
/* ![[previous]](../icons/left.png)
*/
48 {
49 return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
50 }
51
52 /* inode numbers are 16 bit */
53
54 typedef unsigned short 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 unsigned long 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 unsigned short s_isize; /* index of first data zone */
79 unsigned long s_fsize __packed2__; /* total number of zones of this fs */
80 /* the start of the free block list: */
81 unsigned short s_nfree; /* number of free blocks in s_free, <= XENIX_NICFREE */
82 unsigned long s_free[XENIX_NICFREE]; /* first free block list chunk */
83 /* the cache of free inodes: */
84 unsigned short 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 unsigned long s_time __packed2__; /* time of last super block update */
92 unsigned long s_tfree __packed2__; /* total number of free zones */
93 unsigned short s_tinode; /* total number of free inodes */
94 short 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 long s_magic; /* version of file system */
100 long s_type; /* type of file system: 1 for 512 byte blocks
101 2 for 1024 byte blocks */
102 };
103
104 /* Xenix free list block on disk */
105 struct xenix_freelist_chunk {
106 unsigned short fl_nfree; /* number of free blocks in fl_free, <= XENIX_NICFREE] */
107 unsigned long fl_free[XENIX_NICFREE] __packed2__;
108 };
109
110 /* SystemV FS comes in two variants:
111 * sysv2: System V Release 2 (e.g. Microport), structure elements aligned(2).
112 * sysv4: System V Release 4 (e.g. Consensys), structure elements aligned(4).
113 */
114 #define SYSV_NICINOD 100 /* number of inode cache entries */
115 #define SYSV_NICFREE 50 /* number of free block list chunk entries */
116
117 /* SystemV4 super-block data on disk */
118 struct sysv4_super_block {
119 unsigned short s_isize; /* index of first data zone */
120 unsigned long s_fsize; /* total number of zones of this fs */
121 /* the start of the free block list: */
122 unsigned short s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
123 unsigned long s_free[SYSV_NICFREE]; /* first free block list chunk */
124 /* the cache of free inodes: */
125 unsigned short s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
126 sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
127 /* locks, not used by Linux: */
128 char s_flock; /* lock during free block list manipulation */
129 char s_ilock; /* lock during inode cache manipulation */
130 char s_fmod; /* super-block modified flag */
131 char s_ronly; /* flag whether fs is mounted read-only */
132 unsigned long s_time; /* time of last super block update */
133 short s_dinfo[4]; /* device information ?? */
134 unsigned long s_tfree; /* total number of free zones */
135 unsigned short s_tinode; /* total number of free inodes */
136 char s_fname[6]; /* file system volume name */
137 char s_fpack[6]; /* file system pack name */
138 long s_fill[12];
139 long s_state; /* file system state */
140 long s_magic; /* version of file system */
141 long s_type; /* type of file system: 1 for 512 byte blocks
142 2 for 1024 byte blocks */
143 };
144
145 /* SystemV4 free list block on disk */
146 struct sysv4_freelist_chunk {
147 unsigned short fl_nfree; /* number of free blocks in fl_free, <= SYSV_NICFREE] */
148 unsigned long fl_free[SYSV_NICFREE];
149 };
150
151 /* SystemV2 super-block data on disk */
152 struct sysv2_super_block {
153 unsigned short s_isize; /* index of first data zone */
154 unsigned long s_fsize __packed2__; /* total number of zones of this fs */
155 /* the start of the free block list: */
156 unsigned short s_nfree; /* number of free blocks in s_free, <= SYSV_NICFREE */
157 unsigned long s_free[SYSV_NICFREE]; /* first free block list chunk */
158 /* the cache of free inodes: */
159 unsigned short s_ninode; /* number of free inodes in s_inode, <= SYSV_NICINOD */
160 sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */
161 /* locks, not used by Linux: */
162 char s_flock; /* lock during free block list manipulation */
163 char s_ilock; /* lock during inode cache manipulation */
164 char s_fmod; /* super-block modified flag */
165 char s_ronly; /* flag whether fs is mounted read-only */
166 unsigned long s_time __packed2__; /* time of last super block update */
167 short s_dinfo[4]; /* device information ?? */
168 unsigned long s_tfree __packed2__; /* total number of free zones */
169 unsigned short s_tinode; /* total number of free inodes */
170 char s_fname[6]; /* file system volume name */
171 char s_fpack[6]; /* file system pack name */
172 long s_fill[14];
173 long s_state; /* file system state */
174 long s_magic; /* version of file system */
175 long s_type; /* type of file system: 1 for 512 byte blocks
176 2 for 1024 byte blocks */
177 };
178
179 /* SystemV2 free list block on disk */
180 struct sysv2_freelist_chunk {
181 unsigned short fl_nfree; /* number of free blocks in fl_free, <= SYSV_NICFREE] */
182 unsigned long fl_free[SYSV_NICFREE] __packed2__;
183 };
184
185 /* Coherent super-block data on disk */
186 #define COH_NICINOD 100 /* number of inode cache entries */
187 #define COH_NICFREE 64 /* number of free block list chunk entries */
188 struct coh_super_block {
189 unsigned short s_isize; /* index of first data zone */
190 coh_ulong s_fsize __packed2__; /* total number of zones of this fs */
191 /* the start of the free block list: */
192 unsigned short s_nfree; /* number of free blocks in s_free, <= COH_NICFREE */
193 coh_ulong s_free[COH_NICFREE] __packed2__; /* first free block list chunk */
194 /* the cache of free inodes: */
195 unsigned short s_ninode; /* number of free inodes in s_inode, <= COH_NICINOD */
196 sysv_ino_t s_inode[COH_NICINOD]; /* some free inodes */
197 /* locks, not used by Linux: */
198 char s_flock; /* lock during free block list manipulation */
199 char s_ilock; /* lock during inode cache manipulation */
200 char s_fmod; /* super-block modified flag */
201 char s_ronly; /* flag whether fs is mounted read-only */
202 coh_ulong s_time __packed2__; /* time of last super block update */
203 coh_ulong s_tfree __packed2__; /* total number of free zones */
204 unsigned short s_tinode; /* total number of free inodes */
205 unsigned short s_interleave_m; /* interleave factor */
206 unsigned short s_interleave_n;
207 char s_fname[6]; /* file system volume name */
208 char s_fpack[6]; /* file system pack name */
209 unsigned long s_unique; /* zero, not used */
210 };
211
212 /* Coherent free list block on disk */
213 struct coh_freelist_chunk {
214 unsigned short fl_nfree; /* number of free blocks in fl_free, <= COH_NICFREE] */
215 unsigned long fl_free[COH_NICFREE] __packed2__;
216 };
217
218
219 /* SystemV/Coherent inode data on disk */
220
221 struct sysv_inode {
222 unsigned short i_mode;
223 unsigned short i_nlink;
224 unsigned short i_uid;
225 unsigned short i_gid;
226 unsigned long i_size;
227 union { /* directories, regular files, ... */
228 char i_addb[3*(10+1+1+1)+1]; /* zone numbers: max. 10 data blocks,
229 * then 1 indirection block,
230 * then 1 double indirection block,
231 * then 1 triple indirection block.
232 * Then maybe a "file generation number" ??
233 */
234 /* devices */
235 dev_t i_rdev;
236 /* named pipes on Coherent */
237 struct {
238 char p_addp[30];
239 short p_pnc;
240 short p_prx;
241 short p_pwx;
242 } i_p;
243 } i_a;
244 unsigned long i_atime; /* time of last access */
245 unsigned long i_mtime; /* time of last modification */
246 unsigned long i_ctime; /* time of creation */
247 };
248
249 /* The admissible values for i_mode are listed in <linux/stat.h> :
250 * #define S_IFMT 00170000 mask for type
251 * #define S_IFREG 0100000 type = regular file
252 * #define S_IFBLK 0060000 type = block device
253 * #define S_IFDIR 0040000 type = directory
254 * #define S_IFCHR 0020000 type = character device
255 * #define S_IFIFO 0010000 type = named pipe
256 * #define S_ISUID 0004000 set user id
257 * #define S_ISGID 0002000 set group id
258 * #define S_ISVTX 0001000 save swapped text even after use
259 * Additionally for SystemV:
260 * #define S_IFLNK 0120000 type = symbolic link
261 * #define S_IFNAM 0050000 type = XENIX special named file ??
262 * Additionally for Coherent:
263 * #define S_IFMPB 0070000 type = multiplexed block device ??
264 * #define S_IFMPC 0030000 type = multiplexed character device ??
265 *
266 * Since Coherent doesn't know about symbolic links, we use a kludgey
267 * implementation of symbolic links: i_mode = COH_KLUDGE_SYMLINK_MODE
268 * denotes a symbolic link. When a regular file should get this mode by
269 * accident, it is automatically converted to COH_KLUDGE_NOT_SYMLINK.
270 * We use S_IFREG because only regular files (and Coherent pipes...) can have
271 * data blocks with arbitrary contents associated with them, and S_ISVTX
272 * ("save swapped text after use") because it is unused on both Linux and
273 * Coherent: Linux does much more intelligent paging, and Coherent hasn't
274 * virtual memory at all.
275 * Same trick for Xenix.
276 */
277 #define COH_KLUDGE_SYMLINK_MODE (S_IFREG | S_ISVTX)
278 #define COH_KLUDGE_NOT_SYMLINK (S_IFREG | S_ISVTX | S_IRUSR) /* force read access */
279 extern inline mode_t from_coh_imode(unsigned short mode)
/* */
280 {
281 if (mode == COH_KLUDGE_SYMLINK_MODE)
282 return (S_IFLNK | 0777);
283 else
284 return mode;
285 }
286 extern inline unsigned short to_coh_imode(mode_t mode)
/* */
287 {
288 if (S_ISLNK(mode))
289 return COH_KLUDGE_SYMLINK_MODE;
290 else if (mode == COH_KLUDGE_SYMLINK_MODE)
291 return COH_KLUDGE_NOT_SYMLINK;
292 else
293 return mode;
294 }
295
296 /* Admissible values for i_nlink: 0.._LINK_MAX */
297 #define XENIX_LINK_MAX 126 /* ?? */
298 #define SYSV_LINK_MAX 126 /* 127? 251? */
299 #define COH_LINK_MAX 10000 /* max number of hard links to an inode */
300
301 /* The number of inodes per block is
302 sb->sv_inodes_per_block = block_size / sizeof(struct sysv_inode) */
303 /* The number of indirect pointers per block is
304 sb->sv_ind_per_block = block_size / sizeof(unsigned long) */
305
306
307 /* SystemV/Coherent directory entry on disk */
308
309 #define SYSV_NAMELEN 14 /* max size of name in struct sysv_dir_entry */
310
311 struct sysv_dir_entry {
312 sysv_ino_t inode;
313 char name[SYSV_NAMELEN]; /* up to 14 characters, the rest are zeroes */
314 };
315
316 #define SYSV_DIRSIZE sizeof(struct sysv_dir_entry) /* size of every directory entry */
317
318
319 /* Operations */
320 /* ========== */
321
322
323 /* identify the FS in memory */
324 #define FSTYPE_XENIX 1
325 #define FSTYPE_SYSV4 2
326 #define FSTYPE_SYSV2 3
327 #define FSTYPE_COH 4
328
329 #define SYSV_MAGIC_BASE 0x012FF7B3
330
331 #define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_XENIX)
332 #define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
333 #define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
334 #define COH_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_COH)
335
336 /* Because the block size may be smaller than 1024 (which is the unit used by
337 the disk drivers and the buffer code), many functions must return a pointer
338 to the buffer data additionally to the buffer head pointer.
339 */
340 #if 0
341 struct bh_data {
342 struct buffer_head * bh;
343 char * bh_data;
344 };
345 #endif
346
347 /* sysv_bread(sb,dev,block,...) would be equivalent to
348 bread(dev,block,BLOCK_SIZE)
349 if the block size were always 1024, which is the only one bread() supports.
350 */
351 static inline struct buffer_head *
352 sysv_bread (struct super_block *sb, int dev, unsigned int block, char* * data)
/* */
353 {
354 struct buffer_head *bh;
355
356 if (!(bh = bread (dev, (block >> sb->sv_block_size_ratio_bits) + sb->sv_block_base, BLOCK_SIZE)))
357 return NULL;
358 *data = bh->b_data + ((block & sb->sv_block_size_ratio_1) << sb->sv_block_size_bits);
359 return bh;
360 }
361
362
363 /* locks - protect against simultaneous write and truncate */
364
365 extern void _coh_wait_on_inode (struct inode * inode);
366
367 extern inline void coh_wait_on_inode (struct inode * inode)
/* */
368 {
369 if (inode->u.sysv_i.i_lock)
370 _coh_wait_on_inode(inode);
371 }
372
373 extern inline void coh_lock_inode (struct inode * inode)
/* */
374 {
375 if (inode->u.sysv_i.i_lock)
376 _coh_wait_on_inode(inode);
377 inode->u.sysv_i.i_lock = 1;
378 }
379
380 extern inline void coh_unlock_inode (struct inode * inode)
/* ![[last]](../icons/n_last.png)
*/
381 {
382 inode->u.sysv_i.i_lock = 0;
383 wake_up(&inode->u.sysv_i.i_wait);
384 }
385
386
387 /*
388 * Function prototypes
389 */
390
391 extern int sysv_lookup(struct inode * dir,const char * name, int len,
392 struct inode ** result);
393 extern int sysv_create(struct inode * dir,const char * name, int len, int mode,
394 struct inode ** result);
395 extern int sysv_mkdir(struct inode * dir, const char * name, int len, int mode);
396 extern int sysv_rmdir(struct inode * dir, const char * name, int len);
397 extern int sysv_unlink(struct inode * dir, const char * name, int len);
398 extern int sysv_symlink(struct inode * inode, const char * name, int len,
399 const char * symname);
400 extern int sysv_link(struct inode * oldinode, struct inode * dir, const char * name, int len);
401 extern int sysv_mknod(struct inode * dir, const char * name, int len, int mode, int rdev);
402 extern int sysv_rename(struct inode * old_dir, const char * old_name, int old_len,
403 struct inode * new_dir, const char * new_name, int new_len);
404 extern struct inode * sysv_new_inode(const struct inode * dir);
405 extern void sysv_free_inode(struct inode * inode);
406 extern unsigned long sysv_count_free_inodes(struct super_block *sb);
407 extern int sysv_new_block(struct super_block * sb);
408 extern void sysv_free_block(struct super_block * sb, unsigned int block);
409 extern unsigned long sysv_count_free_blocks(struct super_block *sb);
410
411 extern int sysv_bmap(struct inode *,int);
412
413 extern struct buffer_head * sysv_getblk(struct inode *, unsigned int, int, char* *);
414 extern struct buffer_head * sysv_file_bread(struct inode *, int, int, char* *);
415
416 extern void sysv_truncate(struct inode *);
417 extern void sysv_put_super(struct super_block *);
418 extern struct super_block *sysv_read_super(struct super_block *,void *,int);
419 extern void sysv_write_super(struct super_block *);
420 extern void sysv_read_inode(struct inode *);
421 extern int sysv_notify_change(int,struct inode *);
422 extern void sysv_write_inode(struct inode *);
423 extern void sysv_put_inode(struct inode *);
424 extern void sysv_statfs(struct super_block *, struct statfs *);
425 extern int sysv_sync_inode(struct inode *);
426 extern int sysv_sync_file(struct inode *, struct file *);
427 #if 0
428 extern int sysv_mmap(struct inode *, struct file *, unsigned long, size_t, int, unsigned long);
429 #endif
430
431 extern struct inode_operations sysv_file_inode_operations;
432 extern struct inode_operations sysv_file_inode_operations_with_bmap;
433 extern struct inode_operations sysv_dir_inode_operations;
434 extern struct inode_operations sysv_symlink_inode_operations;
435
436 #endif
437
![[bottom]](../icons/n_bottom.png){kind=icon}
*/