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