1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/affs/amigaffs.c |
4 | * |
5 | * (c) 1996 Hans-Joachim Widmaier - Rewritten |
6 | * |
7 | * (C) 1993 Ray Burr - Amiga FFS filesystem. |
8 | * |
9 | * Please send bug reports to: hjw@zvw.de |
10 | */ |
11 | |
12 | #include <linux/math64.h> |
13 | #include <linux/iversion.h> |
14 | #include "affs.h" |
15 | |
16 | /* |
17 | * Functions for accessing Amiga-FFS structures. |
18 | */ |
19 | |
20 | |
21 | /* Insert a header block bh into the directory dir |
22 | * caller must hold AFFS_DIR->i_hash_lock! |
23 | */ |
24 | |
25 | int |
26 | affs_insert_hash(struct inode *dir, struct buffer_head *bh) |
27 | { |
28 | struct super_block *sb = dir->i_sb; |
29 | struct buffer_head *dir_bh; |
30 | u32 ino, hash_ino; |
31 | int offset; |
32 | |
33 | ino = bh->b_blocknr; |
34 | offset = affs_hash_name(sb, AFFS_TAIL(sb, bh)->name + 1, AFFS_TAIL(sb, bh)->name[0]); |
35 | |
36 | pr_debug("%s(dir=%lu, ino=%d)\n" , __func__, dir->i_ino, ino); |
37 | |
38 | dir_bh = affs_bread(sb, block: dir->i_ino); |
39 | if (!dir_bh) |
40 | return -EIO; |
41 | |
42 | hash_ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[offset]); |
43 | while (hash_ino) { |
44 | affs_brelse(bh: dir_bh); |
45 | dir_bh = affs_bread(sb, block: hash_ino); |
46 | if (!dir_bh) |
47 | return -EIO; |
48 | hash_ino = be32_to_cpu(AFFS_TAIL(sb, dir_bh)->hash_chain); |
49 | } |
50 | AFFS_TAIL(sb, bh)->parent = cpu_to_be32(dir->i_ino); |
51 | AFFS_TAIL(sb, bh)->hash_chain = 0; |
52 | affs_fix_checksum(sb, bh); |
53 | |
54 | if (dir->i_ino == dir_bh->b_blocknr) |
55 | AFFS_HEAD(dir_bh)->table[offset] = cpu_to_be32(ino); |
56 | else |
57 | AFFS_TAIL(sb, dir_bh)->hash_chain = cpu_to_be32(ino); |
58 | |
59 | affs_adjust_checksum(bh: dir_bh, val: ino); |
60 | mark_buffer_dirty_inode(bh: dir_bh, inode: dir); |
61 | affs_brelse(bh: dir_bh); |
62 | |
63 | inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir)); |
64 | inode_inc_iversion(inode: dir); |
65 | mark_inode_dirty(inode: dir); |
66 | |
67 | return 0; |
68 | } |
69 | |
70 | /* Remove a header block from its directory. |
71 | * caller must hold AFFS_DIR->i_hash_lock! |
72 | */ |
73 | |
74 | int |
75 | affs_remove_hash(struct inode *dir, struct buffer_head *rem_bh) |
76 | { |
77 | struct super_block *sb; |
78 | struct buffer_head *bh; |
79 | u32 rem_ino, hash_ino; |
80 | __be32 ino; |
81 | int offset, retval; |
82 | |
83 | sb = dir->i_sb; |
84 | rem_ino = rem_bh->b_blocknr; |
85 | offset = affs_hash_name(sb, AFFS_TAIL(sb, rem_bh)->name+1, AFFS_TAIL(sb, rem_bh)->name[0]); |
86 | pr_debug("%s(dir=%lu, ino=%d, hashval=%d)\n" , __func__, dir->i_ino, |
87 | rem_ino, offset); |
88 | |
89 | bh = affs_bread(sb, block: 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, inode: dir); |
104 | AFFS_TAIL(sb, rem_bh)->parent = 0; |
105 | retval = 0; |
106 | break; |
107 | } |
108 | affs_brelse(bh); |
109 | bh = affs_bread(sb, block: 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 | inode_set_mtime_to_ts(inode: dir, ts: inode_set_ctime_current(inode: dir)); |
118 | inode_inc_iversion(inode: dir); |
119 | mark_inode_dirty(inode: dir); |
120 | |
121 | return retval; |
122 | } |
123 | |
124 | static void |
125 | affs_fix_dcache(struct inode *inode, u32 entry_ino) |
126 | { |
127 | struct dentry *dentry; |
128 | spin_lock(lock: &inode->i_lock); |
129 | hlist_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) { |
130 | if (entry_ino == (u32)(long)dentry->d_fsdata) { |
131 | dentry->d_fsdata = (void *)inode->i_ino; |
132 | break; |
133 | } |
134 | } |
135 | spin_unlock(lock: &inode->i_lock); |
136 | } |
137 | |
138 | |
139 | /* Remove header from link chain */ |
140 | |
141 | static int |
142 | affs_remove_link(struct dentry *dentry) |
143 | { |
144 | struct inode *dir, *inode = d_inode(dentry); |
145 | struct super_block *sb = inode->i_sb; |
146 | struct buffer_head *bh, *link_bh = NULL; |
147 | u32 link_ino, ino; |
148 | int retval; |
149 | |
150 | pr_debug("%s(key=%ld)\n" , __func__, inode->i_ino); |
151 | retval = -EIO; |
152 | bh = affs_bread(sb, block: inode->i_ino); |
153 | if (!bh) |
154 | goto done; |
155 | |
156 | link_ino = (u32)(long)dentry->d_fsdata; |
157 | if (inode->i_ino == link_ino) { |
158 | /* we can't remove the head of the link, as its blocknr is still used as ino, |
159 | * so we remove the block of the first link instead. |
160 | */ |
161 | link_ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain); |
162 | link_bh = affs_bread(sb, block: link_ino); |
163 | if (!link_bh) |
164 | goto done; |
165 | |
166 | dir = affs_iget(sb, be32_to_cpu(AFFS_TAIL(sb, link_bh)->parent)); |
167 | if (IS_ERR(ptr: dir)) { |
168 | retval = PTR_ERR(ptr: dir); |
169 | goto done; |
170 | } |
171 | |
172 | affs_lock_dir(inode: dir); |
173 | /* |
174 | * if there's a dentry for that block, make it |
175 | * refer to inode itself. |
176 | */ |
177 | affs_fix_dcache(inode, entry_ino: link_ino); |
178 | retval = affs_remove_hash(dir, rem_bh: link_bh); |
179 | if (retval) { |
180 | affs_unlock_dir(inode: dir); |
181 | goto done; |
182 | } |
183 | mark_buffer_dirty_inode(bh: link_bh, inode); |
184 | |
185 | memcpy(AFFS_TAIL(sb, bh)->name, AFFS_TAIL(sb, link_bh)->name, 32); |
186 | retval = affs_insert_hash(dir, bh); |
187 | if (retval) { |
188 | affs_unlock_dir(inode: dir); |
189 | goto done; |
190 | } |
191 | mark_buffer_dirty_inode(bh, inode); |
192 | |
193 | affs_unlock_dir(inode: dir); |
194 | iput(dir); |
195 | } else { |
196 | link_bh = affs_bread(sb, block: link_ino); |
197 | if (!link_bh) |
198 | goto done; |
199 | } |
200 | |
201 | while ((ino = be32_to_cpu(AFFS_TAIL(sb, bh)->link_chain)) != 0) { |
202 | if (ino == link_ino) { |
203 | __be32 ino2 = AFFS_TAIL(sb, link_bh)->link_chain; |
204 | AFFS_TAIL(sb, bh)->link_chain = ino2; |
205 | affs_adjust_checksum(bh, be32_to_cpu(ino2) - link_ino); |
206 | mark_buffer_dirty_inode(bh, inode); |
207 | retval = 0; |
208 | /* Fix the link count, if bh is a normal header block without links */ |
209 | switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { |
210 | case ST_LINKDIR: |
211 | case ST_LINKFILE: |
212 | break; |
213 | default: |
214 | if (!AFFS_TAIL(sb, bh)->link_chain) |
215 | set_nlink(inode, nlink: 1); |
216 | } |
217 | affs_free_block(sb, block: link_ino); |
218 | goto done; |
219 | } |
220 | affs_brelse(bh); |
221 | bh = affs_bread(sb, block: ino); |
222 | if (!bh) |
223 | goto done; |
224 | } |
225 | retval = -ENOENT; |
226 | done: |
227 | affs_brelse(bh: link_bh); |
228 | affs_brelse(bh); |
229 | return retval; |
230 | } |
231 | |
232 | |
233 | static int |
234 | affs_empty_dir(struct inode *inode) |
235 | { |
236 | struct super_block *sb = inode->i_sb; |
237 | struct buffer_head *bh; |
238 | int retval, size; |
239 | |
240 | retval = -EIO; |
241 | bh = affs_bread(sb, block: inode->i_ino); |
242 | if (!bh) |
243 | goto done; |
244 | |
245 | retval = -ENOTEMPTY; |
246 | for (size = AFFS_SB(sb)->s_hashsize - 1; size >= 0; size--) |
247 | if (AFFS_HEAD(bh)->table[size]) |
248 | goto not_empty; |
249 | retval = 0; |
250 | not_empty: |
251 | affs_brelse(bh); |
252 | done: |
253 | return retval; |
254 | } |
255 | |
256 | |
257 | /* Remove a filesystem object. If the object to be removed has |
258 | * links to it, one of the links must be changed to inherit |
259 | * the file or directory. As above, any inode will do. |
260 | * The buffer will not be freed. If the header is a link, the |
261 | * block will be marked as free. |
262 | * This function returns a negative error number in case of |
263 | * an error, else 0 if the inode is to be deleted or 1 if not. |
264 | */ |
265 | |
266 | int |
267 | (struct dentry *dentry) |
268 | { |
269 | struct super_block *sb; |
270 | struct inode *inode, *dir; |
271 | struct buffer_head *bh = NULL; |
272 | int retval; |
273 | |
274 | dir = d_inode(dentry: dentry->d_parent); |
275 | sb = dir->i_sb; |
276 | |
277 | retval = -ENOENT; |
278 | inode = d_inode(dentry); |
279 | if (!inode) |
280 | goto done; |
281 | |
282 | pr_debug("%s(key=%ld)\n" , __func__, inode->i_ino); |
283 | retval = -EIO; |
284 | bh = affs_bread(sb, block: (u32)(long)dentry->d_fsdata); |
285 | if (!bh) |
286 | goto done; |
287 | |
288 | affs_lock_link(inode); |
289 | affs_lock_dir(inode: dir); |
290 | switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) { |
291 | case ST_USERDIR: |
292 | /* if we ever want to support links to dirs |
293 | * i_hash_lock of the inode must only be |
294 | * taken after some checks |
295 | */ |
296 | affs_lock_dir(inode); |
297 | retval = affs_empty_dir(inode); |
298 | affs_unlock_dir(inode); |
299 | if (retval) |
300 | goto done_unlock; |
301 | break; |
302 | default: |
303 | break; |
304 | } |
305 | |
306 | retval = affs_remove_hash(dir, rem_bh: bh); |
307 | if (retval) |
308 | goto done_unlock; |
309 | mark_buffer_dirty_inode(bh, inode); |
310 | |
311 | affs_unlock_dir(inode: dir); |
312 | |
313 | if (inode->i_nlink > 1) |
314 | retval = affs_remove_link(dentry); |
315 | else |
316 | clear_nlink(inode); |
317 | affs_unlock_link(inode); |
318 | inode_set_ctime_current(inode); |
319 | mark_inode_dirty(inode); |
320 | |
321 | done: |
322 | affs_brelse(bh); |
323 | return retval; |
324 | |
325 | done_unlock: |
326 | affs_unlock_dir(inode: dir); |
327 | affs_unlock_link(inode); |
328 | goto done; |
329 | } |
330 | |
331 | /* Checksum a block, do various consistency checks and optionally return |
332 | the blocks type number. DATA points to the block. If their pointers |
333 | are non-null, *PTYPE and *STYPE are set to the primary and secondary |
334 | block types respectively, *HASHSIZE is set to the size of the hashtable |
335 | (which lets us calculate the block size). |
336 | Returns non-zero if the block is not consistent. */ |
337 | |
338 | u32 |
339 | affs_checksum_block(struct super_block *sb, struct buffer_head *bh) |
340 | { |
341 | __be32 *ptr = (__be32 *)bh->b_data; |
342 | u32 sum; |
343 | int bsize; |
344 | |
345 | sum = 0; |
346 | for (bsize = sb->s_blocksize / sizeof(__be32); bsize > 0; bsize--) |
347 | sum += be32_to_cpu(*ptr++); |
348 | return sum; |
349 | } |
350 | |
351 | /* |
352 | * Calculate the checksum of a disk block and store it |
353 | * at the indicated position. |
354 | */ |
355 | |
356 | void |
357 | affs_fix_checksum(struct super_block *sb, struct buffer_head *bh) |
358 | { |
359 | int cnt = sb->s_blocksize / sizeof(__be32); |
360 | __be32 *ptr = (__be32 *)bh->b_data; |
361 | u32 checksum; |
362 | __be32 *checksumptr; |
363 | |
364 | checksumptr = ptr + 5; |
365 | *checksumptr = 0; |
366 | for (checksum = 0; cnt > 0; ptr++, cnt--) |
367 | checksum += be32_to_cpu(*ptr); |
368 | *checksumptr = cpu_to_be32(-checksum); |
369 | } |
370 | |
371 | void |
372 | affs_secs_to_datestamp(time64_t secs, struct affs_date *ds) |
373 | { |
374 | u32 days; |
375 | u32 minute; |
376 | s32 rem; |
377 | |
378 | secs -= sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA; |
379 | if (secs < 0) |
380 | secs = 0; |
381 | days = div_s64_rem(dividend: secs, divisor: 86400, remainder: &rem); |
382 | minute = rem / 60; |
383 | rem -= minute * 60; |
384 | |
385 | ds->days = cpu_to_be32(days); |
386 | ds->mins = cpu_to_be32(minute); |
387 | ds->ticks = cpu_to_be32(rem * 50); |
388 | } |
389 | |
390 | umode_t |
391 | affs_prot_to_mode(u32 prot) |
392 | { |
393 | umode_t mode = 0; |
394 | |
395 | if (!(prot & FIBF_NOWRITE)) |
396 | mode |= 0200; |
397 | if (!(prot & FIBF_NOREAD)) |
398 | mode |= 0400; |
399 | if (!(prot & FIBF_NOEXECUTE)) |
400 | mode |= 0100; |
401 | if (prot & FIBF_GRP_WRITE) |
402 | mode |= 0020; |
403 | if (prot & FIBF_GRP_READ) |
404 | mode |= 0040; |
405 | if (prot & FIBF_GRP_EXECUTE) |
406 | mode |= 0010; |
407 | if (prot & FIBF_OTR_WRITE) |
408 | mode |= 0002; |
409 | if (prot & FIBF_OTR_READ) |
410 | mode |= 0004; |
411 | if (prot & FIBF_OTR_EXECUTE) |
412 | mode |= 0001; |
413 | |
414 | return mode; |
415 | } |
416 | |
417 | void |
418 | affs_mode_to_prot(struct inode *inode) |
419 | { |
420 | u32 prot = AFFS_I(inode)->i_protect; |
421 | umode_t mode = inode->i_mode; |
422 | |
423 | /* |
424 | * First, clear all RWED bits for owner, group, other. |
425 | * Then, recalculate them afresh. |
426 | * |
427 | * We'll always clear the delete-inhibit bit for the owner, as that is |
428 | * the classic single-user mode AmigaOS protection bit and we need to |
429 | * stay compatible with all scenarios. |
430 | * |
431 | * Since multi-user AmigaOS is an extension, we'll only set the |
432 | * delete-allow bit if any of the other bits in the same user class |
433 | * (group/other) are used. |
434 | */ |
435 | prot &= ~(FIBF_NOEXECUTE | FIBF_NOREAD |
436 | | FIBF_NOWRITE | FIBF_NODELETE |
437 | | FIBF_GRP_EXECUTE | FIBF_GRP_READ |
438 | | FIBF_GRP_WRITE | FIBF_GRP_DELETE |
439 | | FIBF_OTR_EXECUTE | FIBF_OTR_READ |
440 | | FIBF_OTR_WRITE | FIBF_OTR_DELETE); |
441 | |
442 | /* Classic single-user AmigaOS flags. These are inverted. */ |
443 | if (!(mode & 0100)) |
444 | prot |= FIBF_NOEXECUTE; |
445 | if (!(mode & 0400)) |
446 | prot |= FIBF_NOREAD; |
447 | if (!(mode & 0200)) |
448 | prot |= FIBF_NOWRITE; |
449 | |
450 | /* Multi-user extended flags. Not inverted. */ |
451 | if (mode & 0010) |
452 | prot |= FIBF_GRP_EXECUTE; |
453 | if (mode & 0040) |
454 | prot |= FIBF_GRP_READ; |
455 | if (mode & 0020) |
456 | prot |= FIBF_GRP_WRITE; |
457 | if (mode & 0070) |
458 | prot |= FIBF_GRP_DELETE; |
459 | |
460 | if (mode & 0001) |
461 | prot |= FIBF_OTR_EXECUTE; |
462 | if (mode & 0004) |
463 | prot |= FIBF_OTR_READ; |
464 | if (mode & 0002) |
465 | prot |= FIBF_OTR_WRITE; |
466 | if (mode & 0007) |
467 | prot |= FIBF_OTR_DELETE; |
468 | |
469 | AFFS_I(inode)->i_protect = prot; |
470 | } |
471 | |
472 | void |
473 | affs_error(struct super_block *sb, const char *function, const char *fmt, ...) |
474 | { |
475 | struct va_format vaf; |
476 | va_list args; |
477 | |
478 | va_start(args, fmt); |
479 | vaf.fmt = fmt; |
480 | vaf.va = &args; |
481 | pr_crit("error (device %s): %s(): %pV\n" , sb->s_id, function, &vaf); |
482 | if (!sb_rdonly(sb)) |
483 | pr_warn("Remounting filesystem read-only\n" ); |
484 | sb->s_flags |= SB_RDONLY; |
485 | va_end(args); |
486 | } |
487 | |
488 | void |
489 | affs_warning(struct super_block *sb, const char *function, const char *fmt, ...) |
490 | { |
491 | struct va_format vaf; |
492 | va_list args; |
493 | |
494 | va_start(args, fmt); |
495 | vaf.fmt = fmt; |
496 | vaf.va = &args; |
497 | pr_warn("(device %s): %s(): %pV\n" , sb->s_id, function, &vaf); |
498 | va_end(args); |
499 | } |
500 | |
501 | bool |
502 | affs_nofilenametruncate(const struct dentry *dentry) |
503 | { |
504 | return affs_test_opt(AFFS_SB(dentry->d_sb)->s_flags, SF_NO_TRUNCATE); |
505 | } |
506 | |
507 | /* Check if the name is valid for a affs object. */ |
508 | |
509 | int |
510 | affs_check_name(const unsigned char *name, int len, bool notruncate) |
511 | { |
512 | int i; |
513 | |
514 | if (len > AFFSNAMEMAX) { |
515 | if (notruncate) |
516 | return -ENAMETOOLONG; |
517 | len = AFFSNAMEMAX; |
518 | } |
519 | for (i = 0; i < len; i++) { |
520 | if (name[i] < ' ' || name[i] == ':' |
521 | || (name[i] > 0x7e && name[i] < 0xa0)) |
522 | return -EINVAL; |
523 | } |
524 | |
525 | return 0; |
526 | } |
527 | |
528 | /* This function copies name to bstr, with at most 30 |
529 | * characters length. The bstr will be prepended by |
530 | * a length byte. |
531 | * NOTE: The name will must be already checked by |
532 | * affs_check_name()! |
533 | */ |
534 | |
535 | int |
536 | affs_copy_name(unsigned char *bstr, struct dentry *dentry) |
537 | { |
538 | u32 len = min(dentry->d_name.len, AFFSNAMEMAX); |
539 | |
540 | *bstr++ = len; |
541 | memcpy(bstr, dentry->d_name.name, len); |
542 | return len; |
543 | } |
544 | |