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 <linux/math64.h>
12 #include "affs.h"
13
14 /*
15 * Functions for accessing Amiga-FFS structures.
16 */
17
18
19 /* Insert a header block bh into the directory dir
20 * caller must hold AFFS_DIR->i_hash_lock!
21 */
22
23 int
affs_insert_hash(struct inode * dir,struct buffer_head * bh)24 affs_insert_hash(struct inode *dir, struct buffer_head *bh)
25 {
26 struct super_block *sb = dir->i_sb;
27 struct buffer_head *dir_bh;
28 u32 ino, hash_ino;
29 int offset;
30
31 ino = bh->b_blocknr;
32 offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]);
33
34 pr_debug("%s(dir=%lu, ino=%d)\n", __func__, dir->i_ino, ino);
35
36 dir_bh = affs_bread(sb, dir->i_ino);
37 if (!dir_bh)
38 return -EIO;
39
40 hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]);
41 while (hash_ino) {
42 affs_brelse(dir_bh);
43 dir_bh = affs_bread(sb, hash_ino);
44 if (!dir_bh)
45 return -EIO;
46 hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain);
47 }
48 AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino);
49 AFFS_TAIL(sb, bh)->hash_chain = 0;
50 affs_fix_checksum(sb, bh);
51
52 if (dir->i_ino == dir_bh->b_blocknr)
53 AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino);
54 else
55 AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino);
56
57 affs_adjust_checksum(dir_bh, ino);
58 mark_buffer_dirty_inode(dir_bh, dir);
59 affs_brelse(dir_bh);
60
61 dir->i_mtime = dir->i_ctime = current_time(dir);
62 dir->i_version++;
63 mark_inode_dirty(dir);
64
65 return 0;
66 }
67
68 /* Remove a header block from its directory.
69 * caller must hold AFFS_DIR->i_hash_lock!
70 */
71
72 int
affs_remove_hash(struct inode * dir,struct buffer_head * rem_bh)73 affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh)
74 {
75 struct super_block *sb;
76 struct buffer_head *bh;
77 u32 rem_ino, hash_ino;
78 __be32 ino;
79 int offset, retval;
80
81 sb = dir->i_sb;
82 rem_ino = rem_bh->b_blocknr;
83 offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]);
84 pr_debug("%s(dir=%lu, ino=%d, hashval=%d)\n", __func__, dir->i_ino,
85 rem_ino, offset);
86
87 bh = affs_bread(sb, dir->i_ino);
88 if (!bh)
89 return -EIO;
90
91 retval = -ENOENT;
92 hash_ino = be32_to_cpu(AFFS_HEAD(bh)->table[offset]);
93 while (hash_ino) {
94 if (hash_ino == rem_ino) {
95 ino = AFFS_TAIL(sb, rem_bh)->hash_chain;
96 if (dir->i_ino == bh->b_blocknr)
97 AFFS_HEAD(bh)->table[offset] = ino;
98 else
99 AFFS_TAIL(sb, bh)->hash_chain = ino;
100 affs_adjust_checksum(bh, be32_to_cpu(ino) - hash_ino);
101 mark_buffer_dirty_inode(bh, dir);
102 AFFS_TAIL(sb, rem_bh)->parent = 0;
103 retval = 0;
104 break;
105 }
106 affs_brelse(bh);
107 bh = affs_bread(sb, hash_ino);
108 if (!bh)
109 return -EIO;
110 hash_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
111 }
112
113 affs_brelse(bh);
114
115 dir->i_mtime = dir->i_ctime = current_time(dir);
116 dir->i_version++;
117 mark_inode_dirty(dir);
118
119 return retval;
120 }
121
122 static void
affs_fix_dcache(struct inode * inode,u32 entry_ino)123 affs_fix_dcache(struct inode *inode, u32 entry_ino)
124 {
125 struct dentry *dentry;
126 spin_lock(&inode->i_lock);
127 hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
128 if (entry_ino == (u32)(long)dentry->d_fsdata) {
129 dentry->d_fsdata = (void *)inode->i_ino;
130 break;
131 }
132 }
133 spin_unlock(&inode->i_lock);
134 }
135
136
137 /* Remove header from link chain */
138
139 static int
affs_remove_link(struct dentry * dentry)140 affs_remove_link(struct dentry *dentry)
141 {
142 struct inode *dir, *inode = d_inode(dentry);
143 struct super_block *sb = inode->i_sb;
144 struct buffer_head *bh, *link_bh = NULL;
145 u32 link_ino, ino;
146 int retval;
147
148 pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
149 retval = -EIO;
150 bh = affs_bread(sb, inode->i_ino);
151 if (!bh)
152 goto done;
153
154 link_ino = (u32)(long)dentry->d_fsdata;
155 if (inode->i_ino == link_ino) {
156 /* we can't remove the head of the link, as its blocknr is still used as ino,
157 * so we remove the block of the first link instead.
158 */
159 link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain);
160 link_bh = affs_bread(sb, link_ino);
161 if (!link_bh)
162 goto done;
163
164 dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent));
165 if (IS_ERR(dir)) {
166 retval = PTR_ERR(dir);
167 goto done;
168 }
169
170 affs_lock_dir(dir);
171 /*
172 * if there's a dentry for that block, make it
173 * refer to inode itself.
174 */
175 affs_fix_dcache(inode, link_ino);
176 retval = affs_remove_hash(dir, link_bh);
177 if (retval) {
178 affs_unlock_dir(dir);
179 goto done;
180 }
181 mark_buffer_dirty_inode(link_bh, inode);
182
183 memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32);
184 retval = affs_insert_hash(dir, bh);
185 if (retval) {
186 affs_unlock_dir(dir);
187 goto done;
188 }
189 mark_buffer_dirty_inode(bh, inode);
190
191 affs_unlock_dir(dir);
192 iput(dir);
193 } else {
194 link_bh = affs_bread(sb, link_ino);
195 if (!link_bh)
196 goto done;
197 }
198
199 while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) {
200 if (ino == link_ino) {
201 __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain;
202 AFFS_TAIL(sb, bh)->link_chain = ino2;
203 affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino);
204 mark_buffer_dirty_inode(bh, inode);
205 retval = 0;
206 /* Fix the link count, if bh is a normal header block without links */
207 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
208 case ST_LINKDIR:
209 case ST_LINKFILE:
210 break;
211 default:
212 if (!AFFS_TAIL(sb, bh)->link_chain)
213 set_nlink(inode, 1);
214 }
215 affs_free_block(sb, link_ino);
216 goto done;
217 }
218 affs_brelse(bh);
219 bh = affs_bread(sb, ino);
220 if (!bh)
221 goto done;
222 }
223 retval = -ENOENT;
224 done:
225 affs_brelse(link_bh);
226 affs_brelse(bh);
227 return retval;
228 }
229
230
231 static int
affs_empty_dir(struct inode * inode)232 affs_empty_dir(struct inode *inode)
233 {
234 struct super_block *sb = inode->i_sb;
235 struct buffer_head *bh;
236 int retval, size;
237
238 retval = -EIO;
239 bh = affs_bread(sb, inode->i_ino);
240 if (!bh)
241 goto done;
242
243 retval = -ENOTEMPTY;
244 for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--)
245 if (AFFS_HEAD(bh)->table[size])
246 goto not_empty;
247 retval = 0;
248 not_empty:
249 affs_brelse(bh);
250 done:
251 return retval;
252 }
253
254
255 /* Remove a filesystem object. If the object to be removed has
256 * links to it, one of the links must be changed to inherit
257 * the file or directory. As above, any inode will do.
258 * The buffer will not be freed. If the header is a link, the
259 * block will be marked as free.
260 * This function returns a negative error number in case of
261 * an error, else 0 if the inode is to be deleted or 1 if not.
262 */
263
264 int
affs_remove_header(struct dentry * dentry)265 affs_remove_header(struct dentry *dentry)
266 {
267 struct super_block *sb;
268 struct inode *inode, *dir;
269 struct buffer_head *bh = NULL;
270 int retval;
271
272 dir = d_inode(dentry->d_parent);
273 sb = dir->i_sb;
274
275 retval = -ENOENT;
276 inode = d_inode(dentry);
277 if (!inode)
278 goto done;
279
280 pr_debug("%s(key=%ld)\n", __func__, inode->i_ino);
281 retval = -EIO;
282 bh = affs_bread(sb, (u32)(long)dentry->d_fsdata);
283 if (!bh)
284 goto done;
285
286 affs_lock_link(inode);
287 affs_lock_dir(dir);
288 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
289 case ST_USERDIR:
290 /* if we ever want to support links to dirs
291 * i_hash_lock of the inode must only be
292 * taken after some checks
293 */
294 affs_lock_dir(inode);
295 retval = affs_empty_dir(inode);
296 affs_unlock_dir(inode);
297 if (retval)
298 goto done_unlock;
299 break;
300 default:
301 break;
302 }
303
304 retval = affs_remove_hash(dir, bh);
305 if (retval)
306 goto done_unlock;
307 mark_buffer_dirty_inode(bh, inode);
308
309 affs_unlock_dir(dir);
310
311 if (inode->i_nlink > 1)
312 retval = affs_remove_link(dentry);
313 else
314 clear_nlink(inode);
315 affs_unlock_link(inode);
316 inode->i_ctime = current_time(inode);
317 mark_inode_dirty(inode);
318
319 done:
320 affs_brelse(bh);
321 return retval;
322
323 done_unlock:
324 affs_unlock_dir(dir);
325 affs_unlock_link(inode);
326 goto done;
327 }
328
329 /* Checksum a block, do various consistency checks and optionally return
330 the blocks type number. DATA points to the block. If their pointers
331 are non-null, *PTYPE and *STYPE are set to the primary and secondary
332 block types respectively, *HASHSIZE is set to the size of the hashtable
333 (which lets us calculate the block size).
334 Returns non-zero if the block is not consistent. */
335
336 u32
affs_checksum_block(struct super_block * sb,struct buffer_head * bh)337 affs_checksum_block(struct super_block *sb, struct buffer_head *bh)
338 {
339 __be32 *ptr = (__be32 *)bh->b_data;
340 u32 sum;
341 int bsize;
342
343 sum = 0;
344 for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--)
345 sum += be32_to_cpu(*ptr++);
346 return sum;
347 }
348
349 /*
350 * Calculate the checksum of a disk block and store it
351 * at the indicated position.
352 */
353
354 void
affs_fix_checksum(struct super_block * sb,struct buffer_head * bh)355 affs_fix_checksum(struct super_block *sb, struct buffer_head *bh)
356 {
357 int cnt = sb->s_blocksize / sizeof(__be32);
358 __be32 *ptr = (__be32 *)bh->b_data;
359 u32 checksum;
360 __be32 *checksumptr;
361
362 checksumptr = ptr + 5;
363 *checksumptr = 0;
364 for (checksum = 0; cnt > 0; ptr++, cnt--)
365 checksum += be32_to_cpu(*ptr);
366 *checksumptr = cpu_to_be32(-checksum);
367 }
368
369 void
secs_to_datestamp(time64_t secs,struct affs_date * ds)370 secs_to_datestamp(time64_t secs, struct affs_date *ds)
371 {
372 u32 days;
373 u32 minute;
374 s32 rem;
375
376 secs -= sys_tz.tz_minuteswest * 60 + ((8 * 365 + 2) * 24 * 60 * 60);
377 if (secs < 0)
378 secs = 0;
379 days = div_s64_rem(secs, 86400, &rem);
380 minute = rem / 60;
381 rem -= minute * 60;
382
383 ds->days = cpu_to_be32(days);
384 ds->mins = cpu_to_be32(minute);
385 ds->ticks = cpu_to_be32(rem * 50);
386 }
387
388 umode_t
prot_to_mode(u32 prot)389 prot_to_mode(u32 prot)
390 {
391 umode_t mode = 0;
392
393 if (!(prot & FIBF_NOWRITE))
394 mode |= S_IWUSR;
395 if (!(prot & FIBF_NOREAD))
396 mode |= S_IRUSR;
397 if (!(prot & FIBF_NOEXECUTE))
398 mode |= S_IXUSR;
399 if (prot & FIBF_GRP_WRITE)
400 mode |= S_IWGRP;
401 if (prot & FIBF_GRP_READ)
402 mode |= S_IRGRP;
403 if (prot & FIBF_GRP_EXECUTE)
404 mode |= S_IXGRP;
405 if (prot & FIBF_OTR_WRITE)
406 mode |= S_IWOTH;
407 if (prot & FIBF_OTR_READ)
408 mode |= S_IROTH;
409 if (prot & FIBF_OTR_EXECUTE)
410 mode |= S_IXOTH;
411
412 return mode;
413 }
414
415 void
mode_to_prot(struct inode * inode)416 mode_to_prot(struct inode *inode)
417 {
418 u32 prot = AFFS_I(inode)->i_protect;
419 umode_t mode = inode->i_mode;
420
421 if (!(mode & S_IXUSR))
422 prot |= FIBF_NOEXECUTE;
423 if (!(mode & S_IRUSR))
424 prot |= FIBF_NOREAD;
425 if (!(mode & S_IWUSR))
426 prot |= FIBF_NOWRITE;
427 if (mode & S_IXGRP)
428 prot |= FIBF_GRP_EXECUTE;
429 if (mode & S_IRGRP)
430 prot |= FIBF_GRP_READ;
431 if (mode & S_IWGRP)
432 prot |= FIBF_GRP_WRITE;
433 if (mode & S_IXOTH)
434 prot |= FIBF_OTR_EXECUTE;
435 if (mode & S_IROTH)
436 prot |= FIBF_OTR_READ;
437 if (mode & S_IWOTH)
438 prot |= FIBF_OTR_WRITE;
439
440 AFFS_I(inode)->i_protect = prot;
441 }
442
443 void
affs_error(struct super_block * sb,const char * function,const char * fmt,...)444 affs_error(struct super_block *sb, const char *function, const char *fmt, ...)
445 {
446 struct va_format vaf;
447 va_list args;
448
449 va_start(args, fmt);
450 vaf.fmt = fmt;
451 vaf.va = &args;
452 pr_crit("error (device %s): %s(): %pV\n", sb->s_id, function, &vaf);
453 if (!(sb->s_flags & MS_RDONLY))
454 pr_warn("Remounting filesystem read-only\n");
455 sb->s_flags |= MS_RDONLY;
456 va_end(args);
457 }
458
459 void
affs_warning(struct super_block * sb,const char * function,const char * fmt,...)460 affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
461 {
462 struct va_format vaf;
463 va_list args;
464
465 va_start(args, fmt);
466 vaf.fmt = fmt;
467 vaf.va = &args;
468 pr_warn("(device %s): %s(): %pV\n", sb->s_id, function, &vaf);
469 va_end(args);
470 }
471
472 bool
affs_nofilenametruncate(const struct dentry * dentry)473 affs_nofilenametruncate(const struct dentry *dentry)
474 {
475 return affs_test_opt(AFFS_SB(dentry->d_sb)->s_flags, SF_NO_TRUNCATE);
476 }
477
478 /* Check if the name is valid for a affs object. */
479
480 int
affs_check_name(const unsigned char * name,int len,bool notruncate)481 affs_check_name(const unsigned char *name, int len, bool notruncate)
482 {
483 int i;
484
485 if (len > AFFSNAMEMAX) {
486 if (notruncate)
487 return -ENAMETOOLONG;
488 len = AFFSNAMEMAX;
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 u32 len = min(dentry->d_name.len, AFFSNAMEMAX);
510
511 *bstr++ = len;
512 memcpy(bstr, dentry->d_name.name, len);
513 return len;
514 }
515