1 /*
2 * linux/fs/affs/amigaffs.c
3 *
4 * (c) 1996 Hans-Joachim Widmaier - Rewritten
5 *
6 * (C) 1993 Ray Burr - Amiga FFS filesystem.
7 *
8 * Please send bug reports to: hjw@zvw.de
9 */
10
11 #include <stdarg.h>
12 #include <linux/stat.h>
13 #include <linux/sched.h>
14 #include <linux/affs_fs.h>
15 #include <linux/string.h>
16 #include <linux/locks.h>
17 #include <linux/mm.h>
18 #include <linux/amigaffs.h>
19
20 extern struct timezone sys_tz;
21
22 static char ErrorBuffer[256];
23
24 /*
25 * Functions for accessing Amiga-FFS structures.
26 */
27
28
29 /* Insert a header block bh into the directory dir
30 * caller must hold AFFS_DIR->i_hash_lock!
31 */
32
33 int
affs_insert_hash(struct inode * dir,struct buffer_head * bh)34 affs_insert_hash(struct inode *dir, struct buffer_head *bh)
35 {
36 struct super_block *sb = dir->i_sb;
37 struct buffer_head *dir_bh;
38 u32 ino, hash_ino;
39 int offset;
40
41 ino = bh->b_blocknr;
42 offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
43
44 pr_debug("AFFS: insert_hash(dir=%u, ino=%d)\n", (u32)dir->i_ino, ino);
45
46 dir_bh = affs_bread(sb, dir->i_ino);
47 if (!dir_bh)
48 return -EIO;
49
50 hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
51 while (hash_ino) {
52 affs_brelse(dir_bh);
53 dir_bh = affs_bread(sb, hash_ino);
54 if (!dir_bh)
55 return -EIO;
56 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
57 }
58 AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
59 AFFS_TAIL(sb, bh)->hash_chain = 0;
60 affs_fix_checksum(sb, bh);
61
62 if (dir->i_ino == dir_bh->b_blocknr)
63 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
64 else
65 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
66
67 affs_adjust_checksum(dir_bh, ino);
68 mark_buffer_dirty_inode(dir_bh, dir);
69 affs_brelse(dir_bh);
70
71 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
72 dir->i_version = ++event;
73 mark_inode_dirty(dir);
74
75 return 0;
76 }
77
78 /* Remove a header block from its directory.
79 * caller must hold AFFS_DIR->i_hash_lock!
80 */
81
82 int
affs_remove_hash(struct inode * dir,struct buffer_head * rem_bh)83 affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
84 {
85 struct super_block *sb;
86 struct buffer_head *bh;
87 u32 rem_ino, hash_ino, ino;
88 int offset, retval;
89
90 sb = dir->i_sb;
91 rem_ino = rem_bh->b_blocknr;
92 offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
93 pr_debug("AFFS: remove_hash(dir=%d, ino=%d, hashval=%d)\n", (u32)dir->i_ino, rem_ino, offset);
94
95 bh = affs_bread(sb, dir->i_ino);
96 if (!bh)
97 return -EIO;
98
99 retval = -ENOENT;
100 hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
101 while (hash_ino) {
102 if (hash_ino == rem_ino) {
103 ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
104 if (dir->i_ino == bh->b_blocknr)
105 AFFS_HEAD(bh)->table[offset] = ino;
106 else
107 AFFS_TAIL(sb, bh)->hash_chain = ino;
108 affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
109 mark_buffer_dirty_inode(bh, dir);
110 AFFS_TAIL(sb, rem_bh)->parent = 0;
111 retval = 0;
112 break;
113 }
114 affs_brelse(bh);
115 bh = affs_bread(sb, hash_ino);
116 if (!bh)
117 return -EIO;
118 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
119 }
120
121 affs_brelse(bh);
122
123 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
124 dir->i_version = ++event;
125 mark_inode_dirty(dir);
126
127 return retval;
128 }
129
130 static void
affs_fix_dcache(struct dentry * dentry,u32 entry_ino)131 affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
132 {
133 struct inode *inode = dentry->d_inode;
134 void *data = dentry->d_fsdata;
135 struct list_head *head, *next;
136
137 spin_lock(&dcache_lock);
138 head = &inode->i_dentry;
139 next = head->next;
140 while (next != head) {
141 dentry = list_entry(next, struct dentry, d_alias);
142 if (entry_ino == (u32)(long)dentry->d_fsdata) {
143 dentry->d_fsdata = data;
144 break;
145 }
146 next = next->next;
147 }
148 spin_unlock(&dcache_lock);
149 }
150
151
152 /* Remove header from link chain */
153
154 static int
affs_remove_link(struct dentry * dentry)155 affs_remove_link(struct dentry *dentry)
156 {
157 struct inode *dir, *inode = dentry->d_inode;
158 struct super_block *sb = inode->i_sb;
159 struct buffer_head *bh = NULL, *link_bh = NULL;
160 u32 link_ino, ino;
161 int retval;
162
163 pr_debug("AFFS: remove_link(key=%ld)\n", inode->i_ino);
164 retval = -EIO;
165 bh = affs_bread(sb, inode->i_ino);
166 if (!bh)
167 goto done;
168
169 link_ino = (u32)(long)dentry->d_fsdata;
170 if (inode->i_ino == link_ino) {
171 /* we can't remove the head of the link, as its blocknr is still used as ino,
172 * so we remove the block of the first link instead.
173 */
174 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
175 link_bh = affs_bread(sb, link_ino);
176 if (!link_bh)
177 goto done;
178
179 dir = iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
180 if (!dir)
181 goto done;
182
183 affs_lock_dir(dir);
184 affs_fix_dcache(dentry, link_ino);
185 retval = affs_remove_hash(dir, link_bh);
186 if (retval)
187 goto done;
188 mark_buffer_dirty_inode(link_bh, inode);
189
190 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
191 retval = affs_insert_hash(dir, bh);
192 if (retval)
193 goto done;
194 mark_buffer_dirty_inode(bh, inode);
195
196 affs_unlock_dir(dir);
197 iput(dir);
198 } else {
199 link_bh = affs_bread(sb, link_ino);
200 if (!link_bh)
201 goto done;
202 }
203
204 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain))) {
205 if (ino == link_ino) {
206 ino = AFFS_TAIL(sb, link_bh)->link_chain;
207 AFFS_TAIL(sb, bh)->link_chain = ino;
208 affs_adjust_checksum(bh, be32_to_cpu(ino) - link_ino);
209 mark_buffer_dirty_inode(bh, inode);
210 retval = 0;
211 /* Fix the link count, if bh is a normal header block without links */
212 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
213 case ST_LINKDIR:
214 case ST_LINKFILE:
215 break;
216 default:
217 if (!AFFS_TAIL(sb, bh)->link_chain)
218 inode->i_nlink = 1;
219 }
220 affs_free_block(sb, link_ino);
221 goto done;
222 }
223 affs_brelse(bh);
224 bh = affs_bread(sb, ino);
225 if (!bh)
226 goto done;
227 }
228 retval = -ENOENT;
229 done:
230 affs_brelse(link_bh);
231 affs_brelse(bh);
232 return retval;
233 }
234
235
236 static int
affs_empty_dir(struct inode * inode)237 affs_empty_dir(struct inode *inode)
238 {
239 struct super_block *sb = inode->i_sb;
240 struct buffer_head *bh;
241 int retval, size;
242
243 retval = -EIO;
244 bh = affs_bread(sb, inode->i_ino);
245 if (!bh)
246 goto done;
247
248 retval = -ENOTEMPTY;
249 for (size = AFFS_SB->s_hashsize - 1; size >= 0; size--)
250 if (AFFS_HEAD(bh)->table[size])
251 goto not_empty;
252 retval = 0;
253 not_empty:
254 affs_brelse(bh);
255 done:
256 return retval;
257 }
258
259
260 /* Remove a filesystem object. If the object to be removed has
261 * links to it, one of the links must be changed to inherit
262 * the file or directory. As above, any inode will do.
263 * The buffer will not be freed. If the header is a link, the
264 * block will be marked as free.
265 * This function returns a negative error number in case of
266 * an error, else 0 if the inode is to be deleted or 1 if not.
267 */
268
269 int
affs_remove_header(struct dentry * dentry)270 affs_remove_header(struct dentry *dentry)
271 {
272 struct super_block *sb;
273 struct inode *inode, *dir;
274 struct buffer_head *bh = NULL;
275 int retval;
276
277 dir = dentry->d_parent->d_inode;
278 sb = dir->i_sb;
279
280 retval = -ENOENT;
281 inode = dentry->d_inode;
282 if (!inode)
283 goto done;
284
285 pr_debug("AFFS: remove_header(key=%ld)\n", inode->i_ino);
286 retval = -EIO;
287 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
288 if (!bh)
289 goto done;
290
291 affs_lock_link(inode);
292 affs_lock_dir(dir);
293 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
294 case ST_USERDIR:
295 /* if we ever want to support links to dirs
296 * i_hash_lock of the inode must only be
297 * taken after some checks
298 */
299 affs_lock_dir(inode);
300 retval = affs_empty_dir(inode);
301 affs_unlock_dir(inode);
302 if (retval)
303 goto done_unlock;
304 break;
305 default:
306 break;
307 }
308
309 retval = affs_remove_hash(dir, bh);
310 if (retval)
311 goto done_unlock;
312 mark_buffer_dirty_inode(bh, inode);
313
314 affs_unlock_dir(dir);
315
316 if (inode->i_nlink > 1)
317 retval = affs_remove_link(dentry);
318 else
319 inode->i_nlink = 0;
320 affs_unlock_link(inode);
321 inode->i_ctime = CURRENT_TIME;
322 mark_inode_dirty(inode);
323
324 done:
325 affs_brelse(bh);
326 return retval;
327
328 done_unlock:
329 affs_unlock_dir(dir);
330 affs_unlock_link(inode);
331 goto done;
332 }
333
334 /* Checksum a block, do various consistency checks and optionally return
335 the blocks type number. DATA points to the block. If their pointers
336 are non-null, *PTYPE and *STYPE are set to the primary and secondary
337 block types respectively, *HASHSIZE is set to the size of the hashtable
338 (which lets us calculate the block size).
339 Returns non-zero if the block is not consistent. */
340
341 u32
affs_checksum_block(struct super_block * sb,struct buffer_head * bh)342 affs_checksum_block(struct super_block *sb, struct buffer_head *bh)
343 {
344 u32 *ptr = (u32 *)bh->b_data;
345 u32 sum;
346 int bsize;
347
348 sum = 0;
349 for (bsize = sb->s_blocksize / sizeof(u32); bsize > 0; bsize--)
350 sum += be32_to_cpu(*ptr++);
351 return sum;
352 }
353
354 /*
355 * Calculate the checksum of a disk block and store it
356 * at the indicated position.
357 */
358
359 void
affs_fix_checksum(struct super_block * sb,struct buffer_head * bh)360 affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)
361 {
362 int cnt = sb->s_blocksize / sizeof(u32);
363 u32 *ptr = (u32 *)bh->b_data;
364 u32 checksum, *checksumptr;
365
366 checksumptr = ptr + 5;
367 *checksumptr = 0;
368 for (checksum = 0; cnt > 0; ptr++, cnt--)
369 checksum += be32_to_cpu(*ptr);
370 *checksumptr = cpu_to_be32(-checksum);
371 }
372
373 void
secs_to_datestamp(time_t secs,struct affs_date * ds)374 secs_to_datestamp(time_t secs, struct affs_date *ds)
375 {
376 u32 days;
377 u32 minute;
378
379 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
380 if (secs < 0)
381 secs = 0;
382 days = secs / 86400;
383 secs -= days * 86400;
384 minute = secs / 60;
385 secs -= minute * 60;
386
387 ds->days = be32_to_cpu(days);
388 ds->mins = be32_to_cpu(minute);
389 ds->ticks = be32_to_cpu(secs * 50);
390 }
391
392 mode_t
prot_to_mode(u32 prot)393 prot_to_mode(u32 prot)
394 {
395 int mode = 0;
396
397 if (!(prot & FIBF_NOWRITE))
398 mode |= S_IWUSR;
399 if (!(prot & FIBF_NOREAD))
400 mode |= S_IRUSR;
401 if (!(prot & FIBF_NOEXECUTE))
402 mode |= S_IXUSR;
403 if (prot & FIBF_GRP_WRITE)
404 mode |= S_IWGRP;
405 if (prot & FIBF_GRP_READ)
406 mode |= S_IRGRP;
407 if (prot & FIBF_GRP_EXECUTE)
408 mode |= S_IXGRP;
409 if (prot & FIBF_OTR_WRITE)
410 mode |= S_IWOTH;
411 if (prot & FIBF_OTR_READ)
412 mode |= S_IROTH;
413 if (prot & FIBF_OTR_EXECUTE)
414 mode |= S_IXOTH;
415
416 return mode;
417 }
418
419 void
mode_to_prot(struct inode * inode)420 mode_to_prot(struct inode *inode)
421 {
422 u32 prot = AFFS_INODE->i_protect;
423 mode_t mode = inode->i_mode;
424
425 if (!(mode & S_IXUSR))
426 prot |= FIBF_NOEXECUTE;
427 if (!(mode & S_IRUSR))
428 prot |= FIBF_NOREAD;
429 if (!(mode & S_IWUSR))
430 prot |= FIBF_NOWRITE;
431 if (mode & S_IXGRP)
432 prot |= FIBF_GRP_EXECUTE;
433 if (mode & S_IRGRP)
434 prot |= FIBF_GRP_READ;
435 if (mode & S_IWGRP)
436 prot |= FIBF_GRP_WRITE;
437 if (mode & S_IXOTH)
438 prot |= FIBF_OTR_EXECUTE;
439 if (mode & S_IROTH)
440 prot |= FIBF_OTR_READ;
441 if (mode & S_IWOTH)
442 prot |= FIBF_OTR_WRITE;
443
444 AFFS_INODE->i_protect = prot;
445 }
446
447 void
affs_error(struct super_block * sb,const char * function,const char * fmt,...)448 affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
449 {
450 va_list args;
451
452 va_start(args,fmt);
453 vsprintf(ErrorBuffer,fmt,args);
454 va_end(args);
455
456 printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", bdevname(sb->s_dev),
457 function,ErrorBuffer);
458 if (!(sb->s_flags & MS_RDONLY))
459 printk(KERN_WARNING "AFFS: Remounting filesystem read-only\n");
460 sb->s_flags |= MS_RDONLY;
461 }
462
463 void
affs_warning(struct super_block * sb,const char * function,const char * fmt,...)464 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
465 {
466 va_list args;
467
468 va_start(args,fmt);
469 vsprintf(ErrorBuffer,fmt,args);
470 va_end(args);
471
472 printk(KERN_WARNING "AFFS warning (device %s): %s(): %s\n", bdevname(sb->s_dev),
473 function,ErrorBuffer);
474 }
475
476 /* Check if the name is valid for a affs object. */
477
478 int
affs_check_name(const unsigned char * name,int len)479 affs_check_name(const unsigned char *name, int len)
480 {
481 int i;
482
483 if (len > 30)
484 #ifdef AFFS_NO_TRUNCATE
485 return -ENAMETOOLONG;
486 #else
487 len = 30;
488 #endif
489
490 for (i = 0; i < len; i++) {
491 if (name[i] < ' ' || name[i] == ':'
492 || (name[i] > 0x7e && name[i] < 0xa0))
493 return -EINVAL;
494 }
495
496 return 0;
497 }
498
499 /* This function copies name to bstr, with at most 30
500 * characters length. The bstr will be prepended by
501 * a length byte.
502 * NOTE: The name will must be already checked by
503 * affs_check_name()!
504 */
505
506 int
affs_copy_name(unsigned char * bstr,struct dentry * dentry)507 affs_copy_name(unsigned char *bstr, struct dentry *dentry)
508 {
509 int len = min(dentry->d_name.len, 30u);
510
511 *bstr++ = len;
512 memcpy(bstr, dentry->d_name.name, len);
513 return len;
514 }
515