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 "affs.h"
12
13 extern struct timezone sys_tz;
14
15 static char ErrorBuffer[256];
16
17 /*
18 * Functions for accessing Amiga-FFS structures.
19 */
20
21
22 /* Insert a header block bh into the directory dir
23 * caller must hold AFFS_DIR->i_hash_lock!
24 */
25
26 int
affs_insert_hash(struct inode * dir,struct buffer_head * bh)27 affs_insert_hash(struct inode *dir, struct buffer_head *bh)
28 {
29 struct super_block *sb = dir->i_sb;
30 struct buffer_head *dir_bh;
31 u32 ino, hash_ino;
32 int offset;
33
34 ino = bh->b_blocknr;
35 offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
36
37 pr_debug("AFFS: insert_hash(dir=%u, ino=%d)\n", (u32)dir->i_ino, ino);
38
39 dir_bh = affs_bread(sb, dir->i_ino);
40 if (!dir_bh)
41 return -EIO;
42
43 hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
44 while (hash_ino) {
45 affs_brelse(dir_bh);
46 dir_bh = affs_bread(sb, hash_ino);
47 if (!dir_bh)
48 return -EIO;
49 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
50 }
51 AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
52 AFFS_TAIL(sb, bh)->hash_chain = 0;
53 affs_fix_checksum(sb, bh);
54
55 if (dir->i_ino == dir_bh->b_blocknr)
56 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
57 else
58 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
59
60 affs_adjust_checksum(dir_bh, ino);
61 mark_buffer_dirty_inode(dir_bh, dir);
62 affs_brelse(dir_bh);
63
64 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
65 dir->i_version++;
66 mark_inode_dirty(dir);
67
68 return 0;
69 }
70
71 /* Remove a header block from its directory.
72 * caller must hold AFFS_DIR->i_hash_lock!
73 */
74
75 int
affs_remove_hash(struct inode * dir,struct buffer_head * rem_bh)76 affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
77 {
78 struct super_block *sb;
79 struct buffer_head *bh;
80 u32 rem_ino, hash_ino;
81 __be32 ino;
82 int offset, retval;
83
84 sb = dir->i_sb;
85 rem_ino = rem_bh->b_blocknr;
86 offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
87 pr_debug("AFFS: remove_hash(dir=%d, ino=%d, hashval=%d)\n", (u32)dir->i_ino, rem_ino, offset);
88
89 bh = affs_bread(sb, dir->i_ino);
90 if (!bh)
91 return -EIO;
92
93 retval = -ENOENT;
94 hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
95 while (hash_ino) {
96 if (hash_ino == rem_ino) {
97 ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
98 if (dir->i_ino == bh->b_blocknr)
99 AFFS_HEAD(bh)->table[offset] = ino;
100 else
101 AFFS_TAIL(sb, bh)->hash_chain = ino;
102 affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
103 mark_buffer_dirty_inode(bh, dir);
104 AFFS_TAIL(sb, rem_bh)->parent = 0;
105 retval = 0;
106 break;
107 }
108 affs_brelse(bh);
109 bh = affs_bread(sb, hash_ino);
110 if (!bh)
111 return -EIO;
112 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
113 }
114
115 affs_brelse(bh);
116
117 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
118 dir->i_version++;
119 mark_inode_dirty(dir);
120
121 return retval;
122 }
123
124 static void
affs_fix_dcache(struct dentry * dentry,u32 entry_ino)125 affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
126 {
127 struct inode *inode = dentry->d_inode;
128 void *data = dentry->d_fsdata;
129 struct list_head *head, *next;
130
131 spin_lock(&inode->i_lock);
132 head = &inode->i_dentry;
133 next = head->next;
134 while (next != head) {
135 dentry = list_entry(next, struct dentry, d_alias);
136 if (entry_ino == (u32)(long)dentry->d_fsdata) {
137 dentry->d_fsdata = data;
138 break;
139 }
140 next = next->next;
141 }
142 spin_unlock(&inode->i_lock);
143 }
144
145
146 /* Remove header from link chain */
147
148 static int
affs_remove_link(struct dentry * dentry)149 affs_remove_link(struct dentry *dentry)
150 {
151 struct inode *dir, *inode = dentry->d_inode;
152 struct super_block *sb = inode->i_sb;
153 struct buffer_head *bh = NULL, *link_bh = NULL;
154 u32 link_ino, ino;
155 int retval;
156
157 pr_debug("AFFS: remove_link(key=%ld)\n", inode->i_ino);
158 retval = -EIO;
159 bh = affs_bread(sb, inode->i_ino);
160 if (!bh)
161 goto done;
162
163 link_ino = (u32)(long)dentry->d_fsdata;
164 if (inode->i_ino == link_ino) {
165 /* we can't remove the head of the link, as its blocknr is still used as ino,
166 * so we remove the block of the first link instead.
167 */
168 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
169 link_bh = affs_bread(sb, link_ino);
170 if (!link_bh)
171 goto done;
172
173 dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
174 if (IS_ERR(dir)) {
175 retval = PTR_ERR(dir);
176 goto done;
177 }
178
179 affs_lock_dir(dir);
180 affs_fix_dcache(dentry, link_ino);
181 retval = affs_remove_hash(dir, link_bh);
182 if (retval) {
183 affs_unlock_dir(dir);
184 goto done;
185 }
186 mark_buffer_dirty_inode(link_bh, inode);
187
188 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
189 retval = affs_insert_hash(dir, bh);
190 if (retval) {
191 affs_unlock_dir(dir);
192 goto done;
193 }
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)) != 0) {
205 if (ino == link_ino) {
206 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
207 AFFS_TAIL(sb, bh)->link_chain = ino2;
208 affs_adjust_checksum(bh, be32_to_cpu(ino2) - 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 set_nlink(inode, 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(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 clear_nlink(inode);
320 affs_unlock_link(inode);
321 inode->i_ctime = CURRENT_TIME_SEC;
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 __be32 *ptr = (__be32 *)bh->b_data;
345 u32 sum;
346 int bsize;
347
348 sum = 0;
349 for (bsize = sb->s_blocksize / sizeof(__be32); 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(__be32);
363 __be32 *ptr = (__be32 *)bh->b_data;
364 u32 checksum;
365 __be32 *checksumptr;
366
367 checksumptr = ptr + 5;
368 *checksumptr = 0;
369 for (checksum = 0; cnt > 0; ptr++, cnt--)
370 checksum += be32_to_cpu(*ptr);
371 *checksumptr = cpu_to_be32(-checksum);
372 }
373
374 void
secs_to_datestamp(time_t secs,struct affs_date * ds)375 secs_to_datestamp(time_t secs, struct affs_date *ds)
376 {
377 u32 days;
378 u32 minute;
379
380 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
381 if (secs < 0)
382 secs = 0;
383 days = secs / 86400;
384 secs -= days * 86400;
385 minute = secs / 60;
386 secs -= minute * 60;
387
388 ds->days = cpu_to_be32(days);
389 ds->mins = cpu_to_be32(minute);
390 ds->ticks = cpu_to_be32(secs * 50);
391 }
392
393 umode_t
prot_to_mode(u32 prot)394 prot_to_mode(u32 prot)
395 {
396 umode_t mode = 0;
397
398 if (!(prot & FIBF_NOWRITE))
399 mode |= S_IWUSR;
400 if (!(prot & FIBF_NOREAD))
401 mode |= S_IRUSR;
402 if (!(prot & FIBF_NOEXECUTE))
403 mode |= S_IXUSR;
404 if (prot & FIBF_GRP_WRITE)
405 mode |= S_IWGRP;
406 if (prot & FIBF_GRP_READ)
407 mode |= S_IRGRP;
408 if (prot & FIBF_GRP_EXECUTE)
409 mode |= S_IXGRP;
410 if (prot & FIBF_OTR_WRITE)
411 mode |= S_IWOTH;
412 if (prot & FIBF_OTR_READ)
413 mode |= S_IROTH;
414 if (prot & FIBF_OTR_EXECUTE)
415 mode |= S_IXOTH;
416
417 return mode;
418 }
419
420 void
mode_to_prot(struct inode * inode)421 mode_to_prot(struct inode *inode)
422 {
423 u32 prot = AFFS_I(inode)->i_protect;
424 umode_t mode = inode->i_mode;
425
426 if (!(mode & S_IXUSR))
427 prot |= FIBF_NOEXECUTE;
428 if (!(mode & S_IRUSR))
429 prot |= FIBF_NOREAD;
430 if (!(mode & S_IWUSR))
431 prot |= FIBF_NOWRITE;
432 if (mode & S_IXGRP)
433 prot |= FIBF_GRP_EXECUTE;
434 if (mode & S_IRGRP)
435 prot |= FIBF_GRP_READ;
436 if (mode & S_IWGRP)
437 prot |= FIBF_GRP_WRITE;
438 if (mode & S_IXOTH)
439 prot |= FIBF_OTR_EXECUTE;
440 if (mode & S_IROTH)
441 prot |= FIBF_OTR_READ;
442 if (mode & S_IWOTH)
443 prot |= FIBF_OTR_WRITE;
444
445 AFFS_I(inode)->i_protect = prot;
446 }
447
448 void
affs_error(struct super_block * sb,const char * function,const char * fmt,...)449 affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
450 {
451 va_list args;
452
453 va_start(args,fmt);
454 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
455 va_end(args);
456
457 printk(KERN_CRIT "AFFS error (device %s): %s(): %s\n", sb->s_id,
458 function,ErrorBuffer);
459 if (!(sb->s_flags & MS_RDONLY))
460 printk(KERN_WARNING "AFFS: Remounting filesystem read-only\n");
461 sb->s_flags |= MS_RDONLY;
462 }
463
464 void
affs_warning(struct super_block * sb,const char * function,const char * fmt,...)465 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
466 {
467 va_list args;
468
469 va_start(args,fmt);
470 vsnprintf(ErrorBuffer,sizeof(ErrorBuffer),fmt,args);
471 va_end(args);
472
473 printk(KERN_WARNING "AFFS warning (device %s): %s(): %s\n", sb->s_id,
474 function,ErrorBuffer);
475 }
476
477 /* Check if the name is valid for a affs object. */
478
479 int
affs_check_name(const unsigned char * name,int len)480 affs_check_name(const unsigned char *name, int len)
481 {
482 int i;
483
484 if (len > 30)
485 #ifdef AFFS_NO_TRUNCATE
486 return -ENAMETOOLONG;
487 #else
488 len = 30;
489 #endif
490
491 for (i = 0; i < len; i++) {
492 if (name[i] < ' ' || name[i] == ':'
493 || (name[i] > 0x7e && name[i] < 0xa0))
494 return -EINVAL;
495 }
496
497 return 0;
498 }
499
500 /* This function copies name to bstr, with at most 30
501 * characters length. The bstr will be prepended by
502 * a length byte.
503 * NOTE: The name will must be already checked by
504 * affs_check_name()!
505 */
506
507 int
affs_copy_name(unsigned char * bstr,struct dentry * dentry)508 affs_copy_name(unsigned char *bstr, struct dentry *dentry)
509 {
510 int len = min(dentry->d_name.len, 30u);
511
512 *bstr++ = len;
513 memcpy(bstr, dentry->d_name.name, len);
514 return len;
515 }
516