1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/affs/namei.c
4 *
5 * (c) 1996 Hans-Joachim Widmaier - Rewritten
6 *
7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
8 *
9 * (C) 1991 Linus Torvalds - minix filesystem
10 */
11
12 #include "affs.h"
13 #include <linux/exportfs.h>
14
15 typedef int (*toupper_t)(int);
16
17 /* Simple toupper() for DOS\1 */
18
19 static int
20 affs_toupper(int ch)
21 {
22 return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
23 }
24
25 /* International toupper() for DOS\3 ("international") */
26
27 static int
28 affs_intl_toupper(int ch)
29 {
30 return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
31 && ch <= 0xFE && ch != 0xF7) ?
32 ch - ('a' - 'A') : ch;
33 }
34
35 static inline toupper_t
36 affs_get_toupper(struct super_block *sb)
37 {
38 return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ?
39 affs_intl_toupper : affs_toupper;
40 }
41
42 /*
43 * Note: the dentry argument is the parent dentry.
44 */
45 static inline int
46 __affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t fn, bool notruncate)
47 {
48 const u8 *name = qstr->name;
49 unsigned long hash;
50 int retval;
51 u32 len;
52
53 retval = affs_check_name(qstr->name, qstr->len, notruncate);
54 if (retval)
55 return retval;
56
57 hash = init_name_hash(dentry);
58 len = min(qstr->len, AFFSNAMEMAX);
59 for (; len > 0; name++, len--)
60 hash = partial_name_hash(fn(*name), hash);
61 qstr->hash = end_name_hash(hash);
62
63 return 0;
64 }
65
66 static int
67 affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
68 {
69 return __affs_hash_dentry(dentry, qstr, affs_toupper,
70 affs_nofilenametruncate(dentry));
71
72 }
73
74 static int
75 affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
76 {
77 return __affs_hash_dentry(dentry, qstr, affs_intl_toupper,
78 affs_nofilenametruncate(dentry));
79
80 }
81
82 static inline int __affs_compare_dentry(unsigned int len,
83 const char *str, const struct qstr *name, toupper_t fn,
84 bool notruncate)
85 {
86 const u8 *aname = str;
87 const u8 *bname = name->name;
88
89 /*
90 * 'str' is the name of an already existing dentry, so the name
91 * must be valid. 'name' must be validated first.
92 */
93
94 if (affs_check_name(name->name, name->len, notruncate))
95 return 1;
96
97 /*
98 * If the names are longer than the allowed 30 chars,
99 * the excess is ignored, so their length may differ.
100 */
101 if (len >= AFFSNAMEMAX) {
102 if (name->len < AFFSNAMEMAX)
103 return 1;
104 len = AFFSNAMEMAX;
105 } else if (len != name->len)
106 return 1;
107
108 for (; len > 0; len--)
109 if (fn(*aname++) != fn(*bname++))
110 return 1;
111
112 return 0;
113 }
114
115 static int
116 affs_compare_dentry(const struct dentry *dentry,
117 unsigned int len, const char *str, const struct qstr *name)
118 {
119
120 return __affs_compare_dentry(len, str, name, affs_toupper,
121 affs_nofilenametruncate(dentry));
122 }
123
124 static int
125 affs_intl_compare_dentry(const struct dentry *dentry,
126 unsigned int len, const char *str, const struct qstr *name)
127 {
128 return __affs_compare_dentry(len, str, name, affs_intl_toupper,
129 affs_nofilenametruncate(dentry));
130
131 }
132
133 /*
134 * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
135 */
136
137 static inline int
138 affs_match(struct dentry *dentry, const u8 *name2, toupper_t fn)
139 {
140 const u8 *name = dentry->d_name.name;
141 int len = dentry->d_name.len;
142
143 if (len >= AFFSNAMEMAX) {
144 if (*name2 < AFFSNAMEMAX)
145 return 0;
146 len = AFFSNAMEMAX;
147 } else if (len != *name2)
148 return 0;
149
150 for (name2++; len > 0; len--)
151 if (fn(*name++) != fn(*name2++))
152 return 0;
153 return 1;
154 }
155
156 int
157 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
158 {
159 toupper_t fn = affs_get_toupper(sb);
160 u32 hash;
161
162 hash = len = min(len, AFFSNAMEMAX);
163 for (; len > 0; len--)
164 hash = (hash * 13 + fn(*name++)) & 0x7ff;
165
166 return hash % AFFS_SB(sb)->s_hashsize;
167 }
168
169 static struct buffer_head *
170 affs_find_entry(struct inode *dir, struct dentry *dentry)
171 {
172 struct super_block *sb = dir->i_sb;
173 struct buffer_head *bh;
174 toupper_t fn = affs_get_toupper(sb);
175 u32 key;
176
177 pr_debug("%s(\"%pd\")\n", __func__, dentry);
178
179 bh = affs_bread(sb, dir->i_ino);
180 if (!bh)
181 return ERR_PTR(-EIO);
182
183 key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
184
185 for (;;) {
186 affs_brelse(bh);
187 if (key == 0)
188 return NULL;
189 bh = affs_bread(sb, key);
190 if (!bh)
191 return ERR_PTR(-EIO);
192 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, fn))
193 return bh;
194 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
195 }
196 }
197
198 struct dentry *
199 affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
200 {
201 struct super_block *sb = dir->i_sb;
202 struct buffer_head *bh;
203 struct inode *inode = NULL;
204 struct dentry *res;
205
206 pr_debug("%s(\"%pd\")\n", __func__, dentry);
207
208 affs_lock_dir(dir);
209 bh = affs_find_entry(dir, dentry);
210 if (IS_ERR(bh)) {
211 affs_unlock_dir(dir);
212 return ERR_CAST(bh);
213 }
214 if (bh) {
215 u32 ino = bh->b_blocknr;
216
217 /* store the real header ino in d_fsdata for faster lookups */
218 dentry->d_fsdata = (void *)(long)ino;
219 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
220 //link to dirs disabled
221 //case ST_LINKDIR:
222 case ST_LINKFILE:
223 ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
224 }
225 affs_brelse(bh);
226 inode = affs_iget(sb, ino);
227 }
228 res = d_splice_alias(inode, dentry);
229 if (!IS_ERR_OR_NULL(res))
230 res->d_fsdata = dentry->d_fsdata;
231 affs_unlock_dir(dir);
232 return res;
233 }
234
235 int
236 affs_unlink(struct inode *dir, struct dentry *dentry)
237 {
238 pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
239 d_inode(dentry)->i_ino, dentry);
240
241 return affs_remove_header(dentry);
242 }
243
244 int
245 affs_create(struct mnt_idmap *idmap, struct inode *dir,
246 struct dentry *dentry, umode_t mode, bool excl)
247 {
248 struct super_block *sb = dir->i_sb;
249 struct inode *inode;
250 int error;
251
252 pr_debug("%s(%lu,\"%pd\",0%ho)\n",
253 __func__, dir->i_ino, dentry, mode);
254
255 inode = affs_new_inode(dir);
256 if (!inode)
257 return -ENOSPC;
258
259 inode->i_mode = mode;
260 affs_mode_to_prot(inode);
261 mark_inode_dirty(inode);
262
263 inode->i_op = &affs_file_inode_operations;
264 inode->i_fop = &affs_file_operations;
265 inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ?
266 &affs_aops_ofs : &affs_aops;
267 error = affs_add_entry(dir, inode, dentry, ST_FILE);
268 if (error) {
269 clear_nlink(inode);
270 iput(inode);
271 return error;
272 }
273 return 0;
274 }
275
276 int
277 affs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
278 struct dentry *dentry, umode_t mode)
279 {
280 struct inode *inode;
281 int error;
282
283 pr_debug("%s(%lu,\"%pd\",0%ho)\n",
284 __func__, dir->i_ino, dentry, mode);
285
286 inode = affs_new_inode(dir);
287 if (!inode)
288 return -ENOSPC;
289
290 inode->i_mode = S_IFDIR | mode;
291 affs_mode_to_prot(inode);
292
293 inode->i_op = &affs_dir_inode_operations;
294 inode->i_fop = &affs_dir_operations;
295
296 error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
297 if (error) {
298 clear_nlink(inode);
299 mark_inode_dirty(inode);
300 iput(inode);
301 return error;
302 }
303 return 0;
304 }
305
306 int
307 affs_rmdir(struct inode *dir, struct dentry *dentry)
308 {
309 pr_debug("%s(dir=%lu, %lu \"%pd\")\n", __func__, dir->i_ino,
310 d_inode(dentry)->i_ino, dentry);
311
312 return affs_remove_header(dentry);
313 }
314
315 int
316 affs_symlink(struct mnt_idmap *idmap, struct inode *dir,
317 struct dentry *dentry, const char *symname)
318 {
319 struct super_block *sb = dir->i_sb;
320 struct buffer_head *bh;
321 struct inode *inode;
322 char *p;
323 int i, maxlen, error;
324 char c, lc;
325
326 pr_debug("%s(%lu,\"%pd\" -> \"%s\")\n",
327 __func__, dir->i_ino, dentry, symname);
328
329 maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
330 inode = affs_new_inode(dir);
331 if (!inode)
332 return -ENOSPC;
333
334 inode->i_op = &affs_symlink_inode_operations;
335 inode_nohighmem(inode);
336 inode->i_data.a_ops = &affs_symlink_aops;
337 inode->i_mode = S_IFLNK | 0777;
338 affs_mode_to_prot(inode);
339
340 error = -EIO;
341 bh = affs_bread(sb, inode->i_ino);
342 if (!bh)
343 goto err;
344 i = 0;
345 p = (char *)AFFS_HEAD(bh)->table;
346 lc = '/';
347 if (*symname == '/') {
348 struct affs_sb_info *sbi = AFFS_SB(sb);
349 while (*symname == '/')
350 symname++;
351 spin_lock(&sbi->symlink_lock);
352 while (sbi->s_volume[i]) /* Cannot overflow */
353 *p++ = sbi->s_volume[i++];
354 spin_unlock(&sbi->symlink_lock);
355 }
356 while (i < maxlen && (c = *symname++)) {
357 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
358 *p++ = '/';
359 i++;
360 symname += 2;
361 lc = '/';
362 } else if (c == '.' && lc == '/' && *symname == '/') {
363 symname++;
364 lc = '/';
365 } else {
366 *p++ = c;
367 lc = c;
368 i++;
369 }
370 if (lc == '/')
371 while (*symname == '/')
372 symname++;
373 }
374 *p = 0;
375 inode->i_size = i + 1;
376 mark_buffer_dirty_inode(bh, inode);
377 affs_brelse(bh);
378 mark_inode_dirty(inode);
379
380 error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
381 if (error)
382 goto err;
383
384 return 0;
385
386 err:
387 clear_nlink(inode);
388 mark_inode_dirty(inode);
389 iput(inode);
390 return error;
391 }
392
393 int
394 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
395 {
396 struct inode *inode = d_inode(old_dentry);
397
398 pr_debug("%s(%lu, %lu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
399 dentry);
400
401 return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
402 }
403
404 static int
405 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
406 struct inode *new_dir, struct dentry *new_dentry)
407 {
408 struct super_block *sb = old_dir->i_sb;
409 struct buffer_head *bh = NULL;
410 int retval;
411
412 retval = affs_check_name(new_dentry->d_name.name,
413 new_dentry->d_name.len,
414 affs_nofilenametruncate(old_dentry));
415
416 if (retval)
417 return retval;
418
419 /* Unlink destination if it already exists */
420 if (d_really_is_positive(new_dentry)) {
421 retval = affs_remove_header(new_dentry);
422 if (retval)
423 return retval;
424 }
425
426 bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
427 if (!bh)
428 return -EIO;
429
430 /* Remove header from its parent directory. */
431 affs_lock_dir(old_dir);
432 retval = affs_remove_hash(old_dir, bh);
433 affs_unlock_dir(old_dir);
434 if (retval)
435 goto done;
436
437 /* And insert it into the new directory with the new name. */
438 affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
439 affs_fix_checksum(sb, bh);
440 affs_lock_dir(new_dir);
441 retval = affs_insert_hash(new_dir, bh);
442 affs_unlock_dir(new_dir);
443 /* TODO: move it back to old_dir, if error? */
444
445 done:
446 mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
447 affs_brelse(bh);
448 return retval;
449 }
450
451 static int
452 affs_xrename(struct inode *old_dir, struct dentry *old_dentry,
453 struct inode *new_dir, struct dentry *new_dentry)
454 {
455
456 struct super_block *sb = old_dir->i_sb;
457 struct buffer_head *bh_old = NULL;
458 struct buffer_head *bh_new = NULL;
459 int retval;
460
461 bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino);
462 if (!bh_old)
463 return -EIO;
464
465 bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
466 if (!bh_new) {
467 affs_brelse(bh_old);
468 return -EIO;
469 }
470
471 /* Remove old header from its parent directory. */
472 affs_lock_dir(old_dir);
473 retval = affs_remove_hash(old_dir, bh_old);
474 affs_unlock_dir(old_dir);
475 if (retval)
476 goto done;
477
478 /* Remove new header from its parent directory. */
479 affs_lock_dir(new_dir);
480 retval = affs_remove_hash(new_dir, bh_new);
481 affs_unlock_dir(new_dir);
482 if (retval)
483 goto done;
484
485 /* Insert old into the new directory with the new name. */
486 affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry);
487 affs_fix_checksum(sb, bh_old);
488 affs_lock_dir(new_dir);
489 retval = affs_insert_hash(new_dir, bh_old);
490 affs_unlock_dir(new_dir);
491
492 /* Insert new into the old directory with the old name. */
493 affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry);
494 affs_fix_checksum(sb, bh_new);
495 affs_lock_dir(old_dir);
496 retval = affs_insert_hash(old_dir, bh_new);
497 affs_unlock_dir(old_dir);
498 done:
499 mark_buffer_dirty_inode(bh_old, new_dir);
500 mark_buffer_dirty_inode(bh_new, old_dir);
501 affs_brelse(bh_old);
502 affs_brelse(bh_new);
503 return retval;
504 }
505
506 int affs_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
507 struct dentry *old_dentry, struct inode *new_dir,
508 struct dentry *new_dentry, unsigned int flags)
509 {
510
511 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
512 return -EINVAL;
513
514 pr_debug("%s(old=%lu,\"%pd\" to new=%lu,\"%pd\")\n", __func__,
515 old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
516
517 if (flags & RENAME_EXCHANGE)
518 return affs_xrename(old_dir, old_dentry, new_dir, new_dentry);
519
520 return affs_rename(old_dir, old_dentry, new_dir, new_dentry);
521 }
522
523 static struct dentry *affs_get_parent(struct dentry *child)
524 {
525 struct inode *parent;
526 struct buffer_head *bh;
527
528 bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
529 if (!bh)
530 return ERR_PTR(-EIO);
531
532 parent = affs_iget(child->d_sb,
533 be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
534 brelse(bh);
535 return d_obtain_alias(parent);
536 }
537
538 static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
539 u32 generation)
540 {
541 struct inode *inode;
542
543 if (!affs_validblock(sb, ino))
544 return ERR_PTR(-ESTALE);
545
546 inode = affs_iget(sb, ino);
547 if (IS_ERR(inode))
548 return ERR_CAST(inode);
549
550 return inode;
551 }
552
553 static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
554 int fh_len, int fh_type)
555 {
556 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
557 affs_nfs_get_inode);
558 }
559
560 static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
561 int fh_len, int fh_type)
562 {
563 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
564 affs_nfs_get_inode);
565 }
566
567 const struct export_operations affs_export_ops = {
568 .encode_fh = generic_encode_ino32_fh,
569 .fh_to_dentry = affs_fh_to_dentry,
570 .fh_to_parent = affs_fh_to_parent,
571 .get_parent = affs_get_parent,
572 };
573
574 const struct dentry_operations affs_dentry_operations = {
575 .d_hash = affs_hash_dentry,
576 .d_compare = affs_compare_dentry,
577 };
578
579 const struct dentry_operations affs_intl_dentry_operations = {
580 .d_hash = affs_intl_hash_dentry,
581 .d_compare = affs_intl_compare_dentry,
582 };
583
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