File: /usr/src/linux/fs/affs/namei.c
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 <linux/sched.h>
12 #include <linux/affs_fs.h>
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/stat.h>
16 #include <linux/fcntl.h>
17 #include <linux/locks.h>
18 #include <linux/amigaffs.h>
19 #include <asm/uaccess.h>
20
21 #include <linux/errno.h>
22
23 typedef int (*toupper_t)(int);
24
25 extern struct inode_operations affs_symlink_inode_operations;
26
27 static int affs_toupper(int ch);
28 static int affs_hash_dentry(struct dentry *, struct qstr *);
29 static int affs_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
30 static int affs_intl_toupper(int ch);
31 static int affs_intl_hash_dentry(struct dentry *, struct qstr *);
32 static int affs_intl_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
33
34 struct dentry_operations affs_dentry_operations = {
35 d_hash: affs_hash_dentry,
36 d_compare: affs_compare_dentry,
37 };
38
39 struct dentry_operations affs_intl_dentry_operations = {
40 d_hash: affs_intl_hash_dentry,
41 d_compare: affs_intl_compare_dentry,
42 };
43
44
45 /* Simple toupper() for DOS\1 */
46
47 static int
48 affs_toupper(int ch)
49 {
50 return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
51 }
52
53 /* International toupper() for DOS\3 ("international") */
54
55 static int
56 affs_intl_toupper(int ch)
57 {
58 return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
59 && ch <= 0xFE && ch != 0xF7) ?
60 ch - ('a' - 'A') : ch;
61 }
62
63 static inline toupper_t
64 affs_get_toupper(struct super_block *sb)
65 {
66 return AFFS_SB->s_flags & SF_INTL ? affs_intl_toupper : affs_toupper;
67 }
68
69 /*
70 * Note: the dentry argument is the parent dentry.
71 */
72 static inline int
73 __affs_hash_dentry(struct dentry *dentry, struct qstr *qstr, toupper_t toupper)
74 {
75 const u8 *name = qstr->name;
76 unsigned long hash;
77 int i;
78
79 i = affs_check_name(qstr->name,qstr->len);
80 if (i)
81 return i;
82
83 hash = init_name_hash();
84 i = min(qstr->len, 30u);
85 for (; i > 0; name++, i--)
86 hash = partial_name_hash(toupper(*name), hash);
87 qstr->hash = end_name_hash(hash);
88
89 return 0;
90 }
91
92 static int
93 affs_hash_dentry(struct dentry *dentry, struct qstr *qstr)
94 {
95 return __affs_hash_dentry(dentry, qstr, affs_toupper);
96 }
97 static int
98 affs_intl_hash_dentry(struct dentry *dentry, struct qstr *qstr)
99 {
100 return __affs_hash_dentry(dentry, qstr, affs_intl_toupper);
101 }
102
103 static inline int
104 __affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b, toupper_t toupper)
105 {
106 const u8 *aname = a->name;
107 const u8 *bname = b->name;
108 int len;
109
110 /* 'a' is the qstr of an already existing dentry, so the name
111 * must be valid. 'b' must be validated first.
112 */
113
114 if (affs_check_name(b->name,b->len))
115 return 1;
116
117 /* If the names are longer than the allowed 30 chars,
118 * the excess is ignored, so their length may differ.
119 */
120 len = a->len;
121 if (len >= 30) {
122 if (b->len < 30)
123 return 1;
124 len = 30;
125 } else if (len != b->len)
126 return 1;
127
128 for (; len > 0; len--)
129 if (toupper(*aname++) != toupper(*bname++))
130 return 1;
131
132 return 0;
133 }
134
135 static int
136 affs_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
137 {
138 return __affs_compare_dentry(dentry, a, b, affs_toupper);
139 }
140 static int
141 affs_intl_compare_dentry(struct dentry *dentry, struct qstr *a, struct qstr *b)
142 {
143 return __affs_compare_dentry(dentry, a, b, affs_intl_toupper);
144 }
145
146 /*
147 * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
148 */
149
150 static inline int
151 affs_match(struct dentry *dentry, const u8 *name2, toupper_t toupper)
152 {
153 const u8 *name = dentry->d_name.name;
154 int len = dentry->d_name.len;
155
156 if (len >= 30) {
157 if (*name2 < 30)
158 return 0;
159 len = 30;
160 } else if (len != *name2)
161 return 0;
162
163 for (name2++; len > 0; len--)
164 if (toupper(*name++) != toupper(*name2++))
165 return 0;
166 return 1;
167 }
168
169 int
170 affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
171 {
172 toupper_t toupper = affs_get_toupper(sb);
173 int hash;
174
175 hash = len = min(len, 30u);
176 for (; len > 0; len--)
177 hash = (hash * 13 + toupper(*name++)) & 0x7ff;
178
179 return hash % AFFS_SB->s_hashsize;
180 }
181
182 static struct buffer_head *
183 affs_find_entry(struct inode *dir, struct dentry *dentry)
184 {
185 struct super_block *sb = dir->i_sb;
186 struct buffer_head *bh;
187 toupper_t toupper = affs_get_toupper(sb);
188 u32 key;
189
190 pr_debug("AFFS: find_entry(\"%.*s\")\n", (int)dentry->d_name.len, dentry->d_name.name);
191
192 bh = affs_bread(sb, dir->i_ino);
193 if (!bh)
194 return ERR_PTR(-EIO);
195
196 key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
197
198 for (;;) {
199 affs_brelse(bh);
200 if (key == 0)
201 return NULL;
202 bh = affs_bread(sb, key);
203 if (!bh)
204 return ERR_PTR(-EIO);
205 if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, toupper))
206 return bh;
207 key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
208 }
209 }
210
211 struct dentry *
212 affs_lookup(struct inode *dir, struct dentry *dentry)
213 {
214 struct super_block *sb = dir->i_sb;
215 struct buffer_head *bh;
216 struct inode *inode = NULL;
217
218 pr_debug("AFFS: lookup(\"%.*s\")\n",(int)dentry->d_name.len,dentry->d_name.name);
219
220 affs_lock_dir(dir);
221 bh = affs_find_entry(dir, dentry);
222 affs_unlock_dir(dir);
223 if (IS_ERR(bh))
224 return ERR_PTR(PTR_ERR(bh));
225 if (bh) {
226 u32 ino = bh->b_blocknr;
227
228 /* store the real header ino in d_fsdata for faster lookups */
229 dentry->d_fsdata = (void *)(long)ino;
230 switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
231 //link to dirs disabled
232 //case ST_LINKDIR:
233 case ST_LINKFILE:
234 ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
235 }
236 affs_brelse(bh);
237 inode = iget(sb, ino);
238 if (!inode)
239 return ERR_PTR(-EACCES);
240 }
241 dentry->d_op = AFFS_SB->s_flags & SF_INTL ? &affs_intl_dentry_operations : &affs_dentry_operations;
242 d_add(dentry, inode);
243 return NULL;
244 }
245
246 int
247 affs_unlink(struct inode *dir, struct dentry *dentry)
248 {
249 pr_debug("AFFS: unlink(dir=%d, \"%.*s\")\n", (u32)dir->i_ino,
250 (int)dentry->d_name.len, dentry->d_name.name);
251
252 if (!dentry->d_inode)
253 return -ENOENT;
254
255 return affs_remove_header(dentry);
256 }
257
258 int
259 affs_create(struct inode *dir, struct dentry *dentry, int mode)
260 {
261 struct super_block *sb = dir->i_sb;
262 struct inode *inode;
263 int error;
264
265 pr_debug("AFFS: create(%lu,\"%.*s\",0%o)\n",dir->i_ino,(int)dentry->d_name.len,
266 dentry->d_name.name,mode);
267
268 inode = affs_new_inode(dir);
269 if (!inode)
270 return -ENOSPC;
271
272 inode->i_mode = mode;
273 mode_to_prot(inode);
274 mark_inode_dirty(inode);
275
276 inode->i_op = &affs_file_inode_operations;
277 inode->i_fop = &affs_file_operations;
278 inode->i_mapping->a_ops = (AFFS_SB->s_flags & SF_OFS) ? &affs_aops_ofs : &affs_aops;
279 error = affs_add_entry(dir, inode, dentry, ST_FILE);
280 if (error) {
281 inode->i_nlink = 0;
282 iput(inode);
283 return error;
284 }
285 return 0;
286 }
287
288 int
289 affs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
290 {
291 struct inode *inode;
292 int error;
293
294 pr_debug("AFFS: mkdir(%lu,\"%.*s\",0%o)\n",dir->i_ino,
295 (int)dentry->d_name.len,dentry->d_name.name,mode);
296
297 inode = affs_new_inode(dir);
298 if (!inode)
299 return -ENOSPC;
300
301 inode->i_mode = S_IFDIR | mode;
302 mode_to_prot(inode);
303
304 inode->i_op = &affs_dir_inode_operations;
305 inode->i_fop = &affs_dir_operations;
306
307 error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
308 if (error) {
309 inode->i_nlink = 0;
310 mark_inode_dirty(inode);
311 iput(inode);
312 return error;
313 }
314 return 0;
315 }
316
317 int
318 affs_rmdir(struct inode *dir, struct dentry *dentry)
319 {
320 pr_debug("AFFS: rmdir(dir=%u, \"%.*s\")\n", (u32)dir->i_ino,
321 (int)dentry->d_name.len, dentry->d_name.name);
322
323 if (!dentry->d_inode)
324 return -ENOENT;
325
326 return affs_remove_header(dentry);
327 }
328
329 int
330 affs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
331 {
332 struct super_block *sb = dir->i_sb;
333 struct buffer_head *bh;
334 struct inode *inode;
335 char *p;
336 int i, maxlen, error;
337 char c, lc;
338
339 pr_debug("AFFS: symlink(%lu,\"%.*s\" -> \"%s\")\n",dir->i_ino,
340 (int)dentry->d_name.len,dentry->d_name.name,symname);
341
342 maxlen = AFFS_SB->s_hashsize * sizeof(u32) - 1;
343 error = -ENOSPC;
344 inode = affs_new_inode(dir);
345 if (!inode)
346 return -ENOSPC;
347
348 inode->i_op = &affs_symlink_inode_operations;
349 inode->i_data.a_ops = &affs_symlink_aops;
350 inode->i_mode = S_IFLNK | 0777;
351 mode_to_prot(inode);
352
353 error = -EIO;
354 bh = affs_bread(sb, inode->i_ino);
355 if (!bh)
356 goto err;
357 i = 0;
358 p = (char *)AFFS_HEAD(bh)->table;
359 lc = '/';
360 if (*symname == '/') {
361 while (*symname == '/')
362 symname++;
363 while (AFFS_SB->s_volume[i]) /* Cannot overflow */
364 *p++ = AFFS_SB->s_volume[i++];
365 }
366 while (i < maxlen && (c = *symname++)) {
367 if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
368 *p++ = '/';
369 i++;
370 symname += 2;
371 lc = '/';
372 } else if (c == '.' && lc == '/' && *symname == '/') {
373 symname++;
374 lc = '/';
375 } else {
376 *p++ = c;
377 lc = c;
378 i++;
379 }
380 if (lc == '/')
381 while (*symname == '/')
382 symname++;
383 }
384 *p = 0;
385 mark_buffer_dirty_inode(bh, inode);
386 affs_brelse(bh);
387 mark_inode_dirty(inode);
388
389 error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
390 if (error)
391 goto err;
392
393 return 0;
394
395 err:
396 inode->i_nlink = 0;
397 mark_inode_dirty(inode);
398 iput(inode);
399 return error;
400 }
401
402 int
403 affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
404 {
405 struct inode *inode = old_dentry->d_inode;
406 int error;
407
408 pr_debug("AFFS: link(%u, %u, \"%.*s\")\n", (u32)inode->i_ino, (u32)dir->i_ino,
409 (int)dentry->d_name.len,dentry->d_name.name);
410
411 if (S_ISDIR(inode->i_mode))
412 return -EPERM;
413
414 error = affs_add_entry(dir, inode, dentry, S_ISDIR(inode->i_mode) ? ST_LINKDIR : ST_LINKFILE);
415 if (error) {
416 inode->i_nlink = 0;
417 mark_inode_dirty(inode);
418 iput(inode);
419 return error;
420 }
421 return 0;
422 }
423
424 int
425 affs_rename(struct inode *old_dir, struct dentry *old_dentry,
426 struct inode *new_dir, struct dentry *new_dentry)
427 {
428 struct super_block *sb = old_dir->i_sb;
429 struct buffer_head *bh = NULL;
430 int retval;
431
432 pr_debug("AFFS: rename(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
433 (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
434 (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);
435
436 if ((retval = affs_check_name(new_dentry->d_name.name,new_dentry->d_name.len)))
437 goto done;
438
439 /* Unlink destination if it already exists */
440 if (new_dentry->d_inode) {
441 retval = affs_remove_header(new_dentry);
442 if (retval)
443 return retval;
444 }
445
446 retval = -EIO;
447 bh = affs_bread(sb, old_dentry->d_inode->i_ino);
448 if (!bh)
449 goto done;
450
451 /* Remove header from its parent directory. */
452 affs_lock_dir(old_dir);
453 retval = affs_remove_hash(old_dir, bh);
454 affs_unlock_dir(old_dir);
455 if (retval)
456 goto done;
457
458 /* And insert it into the new directory with the new name. */
459 affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
460 affs_fix_checksum(sb, bh);
461 affs_lock_dir(new_dir);
462 retval = affs_insert_hash(new_dir, bh);
463 affs_unlock_dir(new_dir);
464 /* TODO: move it back to old_dir, if error? */
465
466 done:
467 mark_buffer_dirty_inode(bh, retval ? old_dir : new_dir);
468 affs_brelse(bh);
469 return retval;
470 }
471