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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/vfat/namei.c | |
3 | * | |
4 | * Written 1992,1993 by Werner Almesberger | |
5 | * | |
6 | * Windows95/Windows NT compatible extended MSDOS filesystem | |
7 | * by Gordon Chaffee Copyright (C) 1995. Send bug reports for the | |
8 | * VFAT filesystem to <chaffee@cs.berkeley.edu>. Specify | |
9 | * what file operation caused you trouble and if you can duplicate | |
10 | * the problem, send a script that demonstrates it. | |
11 | * | |
12 | * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de> | |
13 | * | |
14 | * Support Multibyte characters and cleanup by | |
15 | * OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | |
16 | */ | |
17 | ||
18 | #include <linux/module.h> | |
19 | ||
20 | #include <linux/jiffies.h> | |
21 | #include <linux/msdos_fs.h> | |
22 | #include <linux/ctype.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/smp_lock.h> | |
25 | #include <linux/buffer_head.h> | |
26 | #include <linux/namei.h> | |
27 | ||
28 | static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd) | |
29 | { | |
30 | int ret = 1; | |
31 | ||
32 | if (!dentry->d_inode && | |
33 | nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_CREATE)) | |
34 | /* | |
35 | * negative dentry is dropped, in order to make sure | |
36 | * to use the name which a user desires if this is | |
37 | * create path. | |
38 | */ | |
39 | ret = 0; | |
40 | else { | |
41 | spin_lock(&dentry->d_lock); | |
42 | if (dentry->d_time != dentry->d_parent->d_inode->i_version) | |
43 | ret = 0; | |
44 | spin_unlock(&dentry->d_lock); | |
45 | } | |
46 | return ret; | |
47 | } | |
48 | ||
49 | /* returns the length of a struct qstr, ignoring trailing dots */ | |
50 | static unsigned int vfat_striptail_len(struct qstr *qstr) | |
51 | { | |
52 | unsigned int len = qstr->len; | |
53 | ||
54 | while (len && qstr->name[len - 1] == '.') | |
55 | len--; | |
56 | return len; | |
57 | } | |
58 | ||
59 | /* | |
60 | * Compute the hash for the vfat name corresponding to the dentry. | |
61 | * Note: if the name is invalid, we leave the hash code unchanged so | |
62 | * that the existing dentry can be used. The vfat fs routines will | |
63 | * return ENOENT or EINVAL as appropriate. | |
64 | */ | |
65 | static int vfat_hash(struct dentry *dentry, struct qstr *qstr) | |
66 | { | |
67 | qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr)); | |
68 | return 0; | |
69 | } | |
70 | ||
71 | /* | |
72 | * Compute the hash for the vfat name corresponding to the dentry. | |
73 | * Note: if the name is invalid, we leave the hash code unchanged so | |
74 | * that the existing dentry can be used. The vfat fs routines will | |
75 | * return ENOENT or EINVAL as appropriate. | |
76 | */ | |
77 | static int vfat_hashi(struct dentry *dentry, struct qstr *qstr) | |
78 | { | |
79 | struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io; | |
80 | const unsigned char *name; | |
81 | unsigned int len; | |
82 | unsigned long hash; | |
83 | ||
84 | name = qstr->name; | |
85 | len = vfat_striptail_len(qstr); | |
86 | ||
87 | hash = init_name_hash(); | |
88 | while (len--) | |
89 | hash = partial_name_hash(nls_tolower(t, *name++), hash); | |
90 | qstr->hash = end_name_hash(hash); | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
95 | /* | |
96 | * Case insensitive compare of two vfat names. | |
97 | */ | |
98 | static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b) | |
99 | { | |
100 | struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io; | |
101 | unsigned int alen, blen; | |
102 | ||
103 | /* A filename cannot end in '.' or we treat it like it has none */ | |
104 | alen = vfat_striptail_len(a); | |
105 | blen = vfat_striptail_len(b); | |
106 | if (alen == blen) { | |
107 | if (nls_strnicmp(t, a->name, b->name, alen) == 0) | |
108 | return 0; | |
109 | } | |
110 | return 1; | |
111 | } | |
112 | ||
113 | /* | |
114 | * Case sensitive compare of two vfat names. | |
115 | */ | |
116 | static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b) | |
117 | { | |
118 | unsigned int alen, blen; | |
119 | ||
120 | /* A filename cannot end in '.' or we treat it like it has none */ | |
121 | alen = vfat_striptail_len(a); | |
122 | blen = vfat_striptail_len(b); | |
123 | if (alen == blen) { | |
124 | if (strncmp(a->name, b->name, alen) == 0) | |
125 | return 0; | |
126 | } | |
127 | return 1; | |
128 | } | |
129 | ||
130 | static struct dentry_operations vfat_dentry_ops[4] = { | |
131 | { | |
132 | .d_hash = vfat_hashi, | |
133 | .d_compare = vfat_cmpi, | |
134 | }, | |
135 | { | |
136 | .d_revalidate = vfat_revalidate, | |
137 | .d_hash = vfat_hashi, | |
138 | .d_compare = vfat_cmpi, | |
139 | }, | |
140 | { | |
141 | .d_hash = vfat_hash, | |
142 | .d_compare = vfat_cmp, | |
143 | }, | |
144 | { | |
145 | .d_revalidate = vfat_revalidate, | |
146 | .d_hash = vfat_hash, | |
147 | .d_compare = vfat_cmp, | |
148 | } | |
149 | }; | |
150 | ||
151 | /* Characters that are undesirable in an MS-DOS file name */ | |
152 | ||
153 | static inline wchar_t vfat_bad_char(wchar_t w) | |
154 | { | |
155 | return (w < 0x0020) | |
156 | || (w == '*') || (w == '?') || (w == '<') || (w == '>') | |
157 | || (w == '|') || (w == '"') || (w == ':') || (w == '/') | |
158 | || (w == '\\'); | |
159 | } | |
160 | ||
161 | static inline wchar_t vfat_replace_char(wchar_t w) | |
162 | { | |
163 | return (w == '[') || (w == ']') || (w == ';') || (w == ',') | |
164 | || (w == '+') || (w == '='); | |
165 | } | |
166 | ||
167 | static wchar_t vfat_skip_char(wchar_t w) | |
168 | { | |
169 | return (w == '.') || (w == ' '); | |
170 | } | |
171 | ||
172 | static inline int vfat_is_used_badchars(const wchar_t *s, int len) | |
173 | { | |
174 | int i; | |
175 | ||
176 | for (i = 0; i < len; i++) | |
177 | if (vfat_bad_char(s[i])) | |
178 | return -EINVAL; | |
179 | return 0; | |
180 | } | |
181 | ||
182 | static int vfat_valid_longname(const unsigned char *name, unsigned int len) | |
183 | { | |
184 | if (name[len - 1] == ' ') | |
185 | return -EINVAL; | |
186 | if (len >= 256) | |
187 | return -ENAMETOOLONG; | |
1da177e4 LT |
188 | return 0; |
189 | } | |
190 | ||
191 | static int vfat_find_form(struct inode *dir, unsigned char *name) | |
192 | { | |
193 | struct fat_slot_info sinfo; | |
194 | int err = fat_scan(dir, name, &sinfo); | |
195 | if (err) | |
196 | return -ENOENT; | |
197 | brelse(sinfo.bh); | |
198 | return 0; | |
199 | } | |
200 | ||
201 | /* | |
202 | * 1) Valid characters for the 8.3 format alias are any combination of | |
203 | * letters, uppercase alphabets, digits, any of the | |
204 | * following special characters: | |
205 | * $ % ' ` - @ { } ~ ! # ( ) & _ ^ | |
206 | * In this case Longfilename is not stored in disk. | |
207 | * | |
208 | * WinNT's Extension: | |
209 | * File name and extension name is contain uppercase/lowercase | |
210 | * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT. | |
211 | * | |
212 | * 2) File name is 8.3 format, but it contain the uppercase and | |
213 | * lowercase char, muliti bytes char, etc. In this case numtail is not | |
214 | * added, but Longfilename is stored. | |
215 | * | |
216 | * 3) When the one except for the above, or the following special | |
217 | * character are contained: | |
218 | * . [ ] ; , + = | |
219 | * numtail is added, and Longfilename must be stored in disk . | |
220 | */ | |
221 | struct shortname_info { | |
222 | unsigned char lower:1, | |
223 | upper:1, | |
224 | valid:1; | |
225 | }; | |
226 | #define INIT_SHORTNAME_INFO(x) do { \ | |
227 | (x)->lower = 1; \ | |
228 | (x)->upper = 1; \ | |
229 | (x)->valid = 1; \ | |
230 | } while (0) | |
231 | ||
232 | static inline int to_shortname_char(struct nls_table *nls, | |
233 | unsigned char *buf, int buf_size, | |
234 | wchar_t *src, struct shortname_info *info) | |
235 | { | |
236 | int len; | |
237 | ||
238 | if (vfat_skip_char(*src)) { | |
239 | info->valid = 0; | |
240 | return 0; | |
241 | } | |
242 | if (vfat_replace_char(*src)) { | |
243 | info->valid = 0; | |
244 | buf[0] = '_'; | |
245 | return 1; | |
246 | } | |
247 | ||
248 | len = nls->uni2char(*src, buf, buf_size); | |
249 | if (len <= 0) { | |
250 | info->valid = 0; | |
251 | buf[0] = '_'; | |
252 | len = 1; | |
253 | } else if (len == 1) { | |
254 | unsigned char prev = buf[0]; | |
255 | ||
256 | if (buf[0] >= 0x7F) { | |
257 | info->lower = 0; | |
258 | info->upper = 0; | |
259 | } | |
260 | ||
261 | buf[0] = nls_toupper(nls, buf[0]); | |
262 | if (isalpha(buf[0])) { | |
263 | if (buf[0] == prev) | |
264 | info->lower = 0; | |
265 | else | |
266 | info->upper = 0; | |
267 | } | |
268 | } else { | |
269 | info->lower = 0; | |
270 | info->upper = 0; | |
271 | } | |
272 | ||
273 | return len; | |
274 | } | |
275 | ||
276 | /* | |
277 | * Given a valid longname, create a unique shortname. Make sure the | |
278 | * shortname does not exist | |
279 | * Returns negative number on error, 0 for a normal | |
280 | * return, and 1 for valid shortname | |
281 | */ | |
282 | static int vfat_create_shortname(struct inode *dir, struct nls_table *nls, | |
283 | wchar_t *uname, int ulen, | |
284 | unsigned char *name_res, unsigned char *lcase) | |
285 | { | |
286 | struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options; | |
287 | wchar_t *ip, *ext_start, *end, *name_start; | |
288 | unsigned char base[9], ext[4], buf[8], *p; | |
289 | unsigned char charbuf[NLS_MAX_CHARSET_SIZE]; | |
290 | int chl, chi; | |
291 | int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen; | |
292 | int is_shortname; | |
293 | struct shortname_info base_info, ext_info; | |
294 | ||
295 | is_shortname = 1; | |
296 | INIT_SHORTNAME_INFO(&base_info); | |
297 | INIT_SHORTNAME_INFO(&ext_info); | |
298 | ||
299 | /* Now, we need to create a shortname from the long name */ | |
300 | ext_start = end = &uname[ulen]; | |
301 | while (--ext_start >= uname) { | |
302 | if (*ext_start == 0x002E) { /* is `.' */ | |
303 | if (ext_start == end - 1) { | |
304 | sz = ulen; | |
305 | ext_start = NULL; | |
306 | } | |
307 | break; | |
308 | } | |
309 | } | |
310 | ||
311 | if (ext_start == uname - 1) { | |
312 | sz = ulen; | |
313 | ext_start = NULL; | |
314 | } else if (ext_start) { | |
315 | /* | |
316 | * Names which start with a dot could be just | |
317 | * an extension eg. "...test". In this case Win95 | |
318 | * uses the extension as the name and sets no extension. | |
319 | */ | |
320 | name_start = &uname[0]; | |
321 | while (name_start < ext_start) { | |
322 | if (!vfat_skip_char(*name_start)) | |
323 | break; | |
324 | name_start++; | |
325 | } | |
326 | if (name_start != ext_start) { | |
327 | sz = ext_start - uname; | |
328 | ext_start++; | |
329 | } else { | |
330 | sz = ulen; | |
331 | ext_start = NULL; | |
332 | } | |
333 | } | |
334 | ||
335 | numtail_baselen = 6; | |
336 | numtail2_baselen = 2; | |
337 | for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) { | |
338 | chl = to_shortname_char(nls, charbuf, sizeof(charbuf), | |
339 | ip, &base_info); | |
340 | if (chl == 0) | |
341 | continue; | |
342 | ||
343 | if (baselen < 2 && (baselen + chl) > 2) | |
344 | numtail2_baselen = baselen; | |
345 | if (baselen < 6 && (baselen + chl) > 6) | |
346 | numtail_baselen = baselen; | |
347 | for (chi = 0; chi < chl; chi++) { | |
348 | *p++ = charbuf[chi]; | |
349 | baselen++; | |
350 | if (baselen >= 8) | |
351 | break; | |
352 | } | |
353 | if (baselen >= 8) { | |
354 | if ((chi < chl - 1) || (ip + 1) - uname < sz) | |
355 | is_shortname = 0; | |
356 | break; | |
357 | } | |
358 | } | |
359 | if (baselen == 0) { | |
360 | return -EINVAL; | |
361 | } | |
362 | ||
363 | extlen = 0; | |
364 | if (ext_start) { | |
365 | for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) { | |
366 | chl = to_shortname_char(nls, charbuf, sizeof(charbuf), | |
367 | ip, &ext_info); | |
368 | if (chl == 0) | |
369 | continue; | |
370 | ||
371 | if ((extlen + chl) > 3) { | |
372 | is_shortname = 0; | |
373 | break; | |
374 | } | |
375 | for (chi = 0; chi < chl; chi++) { | |
376 | *p++ = charbuf[chi]; | |
377 | extlen++; | |
378 | } | |
379 | if (extlen >= 3) { | |
380 | if (ip + 1 != end) | |
381 | is_shortname = 0; | |
382 | break; | |
383 | } | |
384 | } | |
385 | } | |
386 | ext[extlen] = '\0'; | |
387 | base[baselen] = '\0'; | |
388 | ||
389 | /* Yes, it can happen. ".\xe5" would do it. */ | |
390 | if (base[0] == DELETED_FLAG) | |
391 | base[0] = 0x05; | |
392 | ||
393 | /* OK, at this point we know that base is not longer than 8 symbols, | |
394 | * ext is not longer than 3, base is nonempty, both don't contain | |
395 | * any bad symbols (lowercase transformed to uppercase). | |
396 | */ | |
397 | ||
398 | memset(name_res, ' ', MSDOS_NAME); | |
399 | memcpy(name_res, base, baselen); | |
400 | memcpy(name_res + 8, ext, extlen); | |
401 | *lcase = 0; | |
402 | if (is_shortname && base_info.valid && ext_info.valid) { | |
403 | if (vfat_find_form(dir, name_res) == 0) | |
404 | return -EEXIST; | |
405 | ||
406 | if (opts->shortname & VFAT_SFN_CREATE_WIN95) { | |
407 | return (base_info.upper && ext_info.upper); | |
408 | } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) { | |
409 | if ((base_info.upper || base_info.lower) && | |
410 | (ext_info.upper || ext_info.lower)) { | |
411 | if (!base_info.upper && base_info.lower) | |
412 | *lcase |= CASE_LOWER_BASE; | |
413 | if (!ext_info.upper && ext_info.lower) | |
414 | *lcase |= CASE_LOWER_EXT; | |
415 | return 1; | |
416 | } | |
417 | return 0; | |
418 | } else { | |
419 | BUG(); | |
420 | } | |
421 | } | |
422 | ||
423 | if (opts->numtail == 0) | |
424 | if (vfat_find_form(dir, name_res) < 0) | |
425 | return 0; | |
426 | ||
427 | /* | |
428 | * Try to find a unique extension. This used to | |
429 | * iterate through all possibilities sequentially, | |
430 | * but that gave extremely bad performance. Windows | |
431 | * only tries a few cases before using random | |
432 | * values for part of the base. | |
433 | */ | |
434 | ||
435 | if (baselen > 6) { | |
436 | baselen = numtail_baselen; | |
437 | name_res[7] = ' '; | |
438 | } | |
439 | name_res[baselen] = '~'; | |
440 | for (i = 1; i < 10; i++) { | |
441 | name_res[baselen + 1] = i + '0'; | |
442 | if (vfat_find_form(dir, name_res) < 0) | |
443 | return 0; | |
444 | } | |
445 | ||
446 | i = jiffies & 0xffff; | |
447 | sz = (jiffies >> 16) & 0x7; | |
448 | if (baselen > 2) { | |
449 | baselen = numtail2_baselen; | |
450 | name_res[7] = ' '; | |
451 | } | |
452 | name_res[baselen + 4] = '~'; | |
453 | name_res[baselen + 5] = '1' + sz; | |
454 | while (1) { | |
455 | sprintf(buf, "%04X", i); | |
456 | memcpy(&name_res[baselen], buf, 4); | |
457 | if (vfat_find_form(dir, name_res) < 0) | |
458 | break; | |
459 | i -= 11; | |
460 | } | |
461 | return 0; | |
462 | } | |
463 | ||
464 | /* Translate a string, including coded sequences into Unicode */ | |
465 | static int | |
466 | xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, | |
467 | int *longlen, int *outlen, int escape, int utf8, | |
468 | struct nls_table *nls) | |
469 | { | |
470 | const unsigned char *ip; | |
471 | unsigned char nc; | |
472 | unsigned char *op; | |
473 | unsigned int ec; | |
474 | int i, k, fill; | |
475 | int charlen; | |
476 | ||
477 | if (utf8) { | |
478 | int name_len = strlen(name); | |
479 | ||
480 | *outlen = utf8_mbstowcs((wchar_t *)outname, name, PAGE_SIZE); | |
481 | ||
482 | /* | |
483 | * We stripped '.'s before and set len appropriately, | |
484 | * but utf8_mbstowcs doesn't care about len | |
485 | */ | |
486 | *outlen -= (name_len - len); | |
487 | ||
488 | op = &outname[*outlen * sizeof(wchar_t)]; | |
489 | } else { | |
490 | if (nls) { | |
491 | for (i = 0, ip = name, op = outname, *outlen = 0; | |
492 | i < len && *outlen <= 260; | |
493 | *outlen += 1) | |
494 | { | |
495 | if (escape && (*ip == ':')) { | |
496 | if (i > len - 5) | |
497 | return -EINVAL; | |
498 | ec = 0; | |
499 | for (k = 1; k < 5; k++) { | |
500 | nc = ip[k]; | |
501 | ec <<= 4; | |
502 | if (nc >= '0' && nc <= '9') { | |
503 | ec |= nc - '0'; | |
504 | continue; | |
505 | } | |
506 | if (nc >= 'a' && nc <= 'f') { | |
507 | ec |= nc - ('a' - 10); | |
508 | continue; | |
509 | } | |
510 | if (nc >= 'A' && nc <= 'F') { | |
511 | ec |= nc - ('A' - 10); | |
512 | continue; | |
513 | } | |
514 | return -EINVAL; | |
515 | } | |
516 | *op++ = ec & 0xFF; | |
517 | *op++ = ec >> 8; | |
518 | ip += 5; | |
519 | i += 5; | |
520 | } else { | |
521 | if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0) | |
522 | return -EINVAL; | |
523 | ip += charlen; | |
524 | i += charlen; | |
525 | op += 2; | |
526 | } | |
527 | } | |
528 | } else { | |
529 | for (i = 0, ip = name, op = outname, *outlen = 0; | |
530 | i < len && *outlen <= 260; | |
531 | i++, *outlen += 1) | |
532 | { | |
533 | *op++ = *ip++; | |
534 | *op++ = 0; | |
535 | } | |
536 | } | |
537 | } | |
538 | if (*outlen > 260) | |
539 | return -ENAMETOOLONG; | |
540 | ||
541 | *longlen = *outlen; | |
542 | if (*outlen % 13) { | |
543 | *op++ = 0; | |
544 | *op++ = 0; | |
545 | *outlen += 1; | |
546 | if (*outlen % 13) { | |
547 | fill = 13 - (*outlen % 13); | |
548 | for (i = 0; i < fill; i++) { | |
549 | *op++ = 0xff; | |
550 | *op++ = 0xff; | |
551 | } | |
552 | *outlen += fill; | |
553 | } | |
554 | } | |
555 | ||
556 | return 0; | |
557 | } | |
558 | ||
559 | static int vfat_build_slots(struct inode *dir, const unsigned char *name, | |
560 | int len, int is_dir, int cluster, | |
561 | struct timespec *ts, | |
562 | struct msdos_dir_slot *slots, int *nr_slots) | |
563 | { | |
564 | struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); | |
565 | struct fat_mount_options *opts = &sbi->options; | |
566 | struct msdos_dir_slot *ps; | |
567 | struct msdos_dir_entry *de; | |
568 | unsigned long page; | |
569 | unsigned char cksum, lcase; | |
570 | unsigned char msdos_name[MSDOS_NAME]; | |
571 | wchar_t *uname; | |
572 | __le16 time, date; | |
573 | int err, ulen, usize, i; | |
574 | loff_t offset; | |
575 | ||
576 | *nr_slots = 0; | |
577 | err = vfat_valid_longname(name, len); | |
578 | if (err) | |
579 | return err; | |
580 | ||
581 | page = __get_free_page(GFP_KERNEL); | |
582 | if (!page) | |
583 | return -ENOMEM; | |
584 | ||
585 | uname = (wchar_t *)page; | |
586 | err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize, | |
587 | opts->unicode_xlate, opts->utf8, sbi->nls_io); | |
588 | if (err) | |
589 | goto out_free; | |
590 | ||
591 | err = vfat_is_used_badchars(uname, ulen); | |
592 | if (err) | |
593 | goto out_free; | |
594 | ||
595 | err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen, | |
596 | msdos_name, &lcase); | |
597 | if (err < 0) | |
598 | goto out_free; | |
599 | else if (err == 1) { | |
600 | de = (struct msdos_dir_entry *)slots; | |
601 | err = 0; | |
602 | goto shortname; | |
603 | } | |
604 | ||
605 | /* build the entry of long file name */ | |
451cbaa1 | 606 | cksum = fat_checksum(msdos_name); |
1da177e4 LT |
607 | |
608 | *nr_slots = usize / 13; | |
609 | for (ps = slots, i = *nr_slots; i > 0; i--, ps++) { | |
610 | ps->id = i; | |
611 | ps->attr = ATTR_EXT; | |
612 | ps->reserved = 0; | |
613 | ps->alias_checksum = cksum; | |
614 | ps->start = 0; | |
615 | offset = (i - 1) * 13; | |
616 | fatwchar_to16(ps->name0_4, uname + offset, 5); | |
617 | fatwchar_to16(ps->name5_10, uname + offset + 5, 6); | |
618 | fatwchar_to16(ps->name11_12, uname + offset + 11, 2); | |
619 | } | |
620 | slots[0].id |= 0x40; | |
621 | de = (struct msdos_dir_entry *)ps; | |
622 | ||
623 | shortname: | |
624 | /* build the entry of 8.3 alias name */ | |
625 | (*nr_slots)++; | |
626 | memcpy(de->name, msdos_name, MSDOS_NAME); | |
627 | de->attr = is_dir ? ATTR_DIR : ATTR_ARCH; | |
628 | de->lcase = lcase; | |
629 | fat_date_unix2dos(ts->tv_sec, &time, &date); | |
630 | de->time = de->ctime = time; | |
631 | de->date = de->cdate = de->adate = date; | |
632 | de->ctime_cs = 0; | |
633 | de->start = cpu_to_le16(cluster); | |
634 | de->starthi = cpu_to_le16(cluster >> 16); | |
635 | de->size = 0; | |
636 | out_free: | |
637 | free_page(page); | |
638 | return err; | |
639 | } | |
640 | ||
641 | static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir, | |
642 | int cluster, struct timespec *ts, | |
643 | struct fat_slot_info *sinfo) | |
644 | { | |
645 | struct msdos_dir_slot *slots; | |
646 | unsigned int len; | |
647 | int err, nr_slots; | |
648 | ||
649 | len = vfat_striptail_len(qname); | |
650 | if (len == 0) | |
651 | return -ENOENT; | |
652 | ||
653 | slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_KERNEL); | |
654 | if (slots == NULL) | |
655 | return -ENOMEM; | |
656 | ||
657 | err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts, | |
658 | slots, &nr_slots); | |
659 | if (err) | |
660 | goto cleanup; | |
661 | ||
662 | err = fat_add_entries(dir, slots, nr_slots, sinfo); | |
663 | if (err) | |
664 | goto cleanup; | |
665 | ||
666 | /* update timestamp */ | |
667 | dir->i_ctime = dir->i_mtime = dir->i_atime = *ts; | |
668 | if (IS_DIRSYNC(dir)) | |
669 | (void)fat_sync_inode(dir); | |
670 | else | |
671 | mark_inode_dirty(dir); | |
672 | cleanup: | |
673 | kfree(slots); | |
674 | return err; | |
675 | } | |
676 | ||
677 | static int vfat_find(struct inode *dir, struct qstr *qname, | |
678 | struct fat_slot_info *sinfo) | |
679 | { | |
680 | unsigned int len = vfat_striptail_len(qname); | |
681 | if (len == 0) | |
682 | return -ENOENT; | |
683 | return fat_search_long(dir, qname->name, len, sinfo); | |
684 | } | |
685 | ||
686 | static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, | |
687 | struct nameidata *nd) | |
688 | { | |
689 | struct super_block *sb = dir->i_sb; | |
690 | struct fat_slot_info sinfo; | |
691 | struct inode *inode = NULL; | |
692 | struct dentry *alias; | |
693 | int err, table; | |
694 | ||
695 | lock_kernel(); | |
696 | table = (MSDOS_SB(sb)->options.name_check == 's') ? 2 : 0; | |
697 | dentry->d_op = &vfat_dentry_ops[table]; | |
698 | ||
699 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
700 | if (err) { | |
701 | table++; | |
702 | goto error; | |
703 | } | |
704 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
705 | brelse(sinfo.bh); | |
706 | if (IS_ERR(inode)) { | |
707 | unlock_kernel(); | |
708 | return ERR_PTR(PTR_ERR(inode)); | |
709 | } | |
710 | alias = d_find_alias(inode); | |
711 | if (alias) { | |
712 | if (d_invalidate(alias) == 0) | |
713 | dput(alias); | |
714 | else { | |
715 | iput(inode); | |
716 | unlock_kernel(); | |
717 | return alias; | |
718 | } | |
719 | ||
720 | } | |
721 | error: | |
722 | unlock_kernel(); | |
723 | dentry->d_op = &vfat_dentry_ops[table]; | |
724 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
725 | dentry = d_splice_alias(inode, dentry); | |
726 | if (dentry) { | |
727 | dentry->d_op = &vfat_dentry_ops[table]; | |
728 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
729 | } | |
730 | return dentry; | |
731 | } | |
732 | ||
733 | static int vfat_create(struct inode *dir, struct dentry *dentry, int mode, | |
734 | struct nameidata *nd) | |
735 | { | |
736 | struct super_block *sb = dir->i_sb; | |
737 | struct inode *inode; | |
738 | struct fat_slot_info sinfo; | |
739 | struct timespec ts; | |
740 | int err; | |
741 | ||
742 | lock_kernel(); | |
743 | ||
744 | ts = CURRENT_TIME_SEC; | |
745 | err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo); | |
746 | if (err) | |
747 | goto out; | |
748 | dir->i_version++; | |
749 | ||
750 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
751 | brelse(sinfo.bh); | |
752 | if (IS_ERR(inode)) { | |
753 | err = PTR_ERR(inode); | |
754 | goto out; | |
755 | } | |
756 | inode->i_version++; | |
757 | inode->i_mtime = inode->i_atime = inode->i_ctime = ts; | |
758 | /* timestamp is already written, so mark_inode_dirty() is unneeded. */ | |
759 | ||
760 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
761 | d_instantiate(dentry, inode); | |
762 | out: | |
763 | unlock_kernel(); | |
764 | return err; | |
765 | } | |
766 | ||
767 | static int vfat_rmdir(struct inode *dir, struct dentry *dentry) | |
768 | { | |
769 | struct inode *inode = dentry->d_inode; | |
770 | struct fat_slot_info sinfo; | |
771 | int err; | |
772 | ||
773 | lock_kernel(); | |
774 | ||
775 | err = fat_dir_empty(inode); | |
776 | if (err) | |
777 | goto out; | |
778 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
779 | if (err) | |
780 | goto out; | |
781 | ||
782 | err = fat_remove_entries(dir, &sinfo); /* and releases bh */ | |
783 | if (err) | |
784 | goto out; | |
785 | dir->i_nlink--; | |
786 | ||
787 | inode->i_nlink = 0; | |
788 | inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; | |
789 | fat_detach(inode); | |
790 | out: | |
791 | unlock_kernel(); | |
792 | ||
793 | return err; | |
794 | } | |
795 | ||
796 | static int vfat_unlink(struct inode *dir, struct dentry *dentry) | |
797 | { | |
798 | struct inode *inode = dentry->d_inode; | |
799 | struct fat_slot_info sinfo; | |
800 | int err; | |
801 | ||
802 | lock_kernel(); | |
803 | ||
804 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
805 | if (err) | |
806 | goto out; | |
807 | ||
808 | err = fat_remove_entries(dir, &sinfo); /* and releases bh */ | |
809 | if (err) | |
810 | goto out; | |
811 | inode->i_nlink = 0; | |
812 | inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; | |
813 | fat_detach(inode); | |
814 | out: | |
815 | unlock_kernel(); | |
816 | ||
817 | return err; | |
818 | } | |
819 | ||
820 | static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
821 | { | |
822 | struct super_block *sb = dir->i_sb; | |
823 | struct inode *inode; | |
824 | struct fat_slot_info sinfo; | |
825 | struct timespec ts; | |
826 | int err, cluster; | |
827 | ||
828 | lock_kernel(); | |
829 | ||
830 | ts = CURRENT_TIME_SEC; | |
831 | cluster = fat_alloc_new_dir(dir, &ts); | |
832 | if (cluster < 0) { | |
833 | err = cluster; | |
834 | goto out; | |
835 | } | |
836 | err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo); | |
837 | if (err) | |
838 | goto out_free; | |
839 | dir->i_version++; | |
840 | dir->i_nlink++; | |
841 | ||
842 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
843 | brelse(sinfo.bh); | |
844 | if (IS_ERR(inode)) { | |
845 | err = PTR_ERR(inode); | |
846 | /* the directory was completed, just return a error */ | |
847 | goto out; | |
848 | } | |
849 | inode->i_version++; | |
850 | inode->i_nlink = 2; | |
851 | inode->i_mtime = inode->i_atime = inode->i_ctime = ts; | |
852 | /* timestamp is already written, so mark_inode_dirty() is unneeded. */ | |
853 | ||
854 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
855 | d_instantiate(dentry, inode); | |
856 | ||
857 | unlock_kernel(); | |
858 | return 0; | |
859 | ||
860 | out_free: | |
861 | fat_free_clusters(dir, cluster); | |
862 | out: | |
863 | unlock_kernel(); | |
864 | return err; | |
865 | } | |
866 | ||
867 | static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, | |
868 | struct inode *new_dir, struct dentry *new_dentry) | |
869 | { | |
870 | struct buffer_head *dotdot_bh; | |
871 | struct msdos_dir_entry *dotdot_de; | |
1da177e4 LT |
872 | struct inode *old_inode, *new_inode; |
873 | struct fat_slot_info old_sinfo, sinfo; | |
874 | struct timespec ts; | |
9131dd42 | 875 | loff_t dotdot_i_pos, new_i_pos; |
1da177e4 LT |
876 | int err, is_dir, update_dotdot, corrupt = 0; |
877 | ||
878 | old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; | |
879 | old_inode = old_dentry->d_inode; | |
880 | new_inode = new_dentry->d_inode; | |
881 | lock_kernel(); | |
882 | err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo); | |
883 | if (err) | |
884 | goto out; | |
885 | ||
886 | is_dir = S_ISDIR(old_inode->i_mode); | |
887 | update_dotdot = (is_dir && old_dir != new_dir); | |
888 | if (update_dotdot) { | |
889 | if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de, | |
890 | &dotdot_i_pos) < 0) { | |
891 | err = -EIO; | |
892 | goto out; | |
893 | } | |
894 | } | |
895 | ||
896 | ts = CURRENT_TIME_SEC; | |
897 | if (new_inode) { | |
1da177e4 LT |
898 | if (is_dir) { |
899 | err = fat_dir_empty(new_inode); | |
900 | if (err) | |
901 | goto out; | |
902 | } | |
9131dd42 | 903 | new_i_pos = MSDOS_I(new_inode)->i_pos; |
1da177e4 LT |
904 | fat_detach(new_inode); |
905 | } else { | |
906 | err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0, | |
907 | &ts, &sinfo); | |
908 | if (err) | |
909 | goto out; | |
9131dd42 | 910 | new_i_pos = sinfo.i_pos; |
1da177e4 LT |
911 | } |
912 | new_dir->i_version++; | |
913 | ||
914 | fat_detach(old_inode); | |
9131dd42 | 915 | fat_attach(old_inode, new_i_pos); |
1da177e4 LT |
916 | if (IS_DIRSYNC(new_dir)) { |
917 | err = fat_sync_inode(old_inode); | |
918 | if (err) | |
919 | goto error_inode; | |
920 | } else | |
921 | mark_inode_dirty(old_inode); | |
922 | ||
923 | if (update_dotdot) { | |
924 | int start = MSDOS_I(new_dir)->i_logstart; | |
925 | dotdot_de->start = cpu_to_le16(start); | |
926 | dotdot_de->starthi = cpu_to_le16(start >> 16); | |
927 | mark_buffer_dirty(dotdot_bh); | |
928 | if (IS_DIRSYNC(new_dir)) { | |
929 | err = sync_dirty_buffer(dotdot_bh); | |
930 | if (err) | |
931 | goto error_dotdot; | |
932 | } | |
933 | old_dir->i_nlink--; | |
934 | if (!new_inode) | |
935 | new_dir->i_nlink++; | |
936 | } | |
937 | ||
938 | err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ | |
939 | old_sinfo.bh = NULL; | |
940 | if (err) | |
941 | goto error_dotdot; | |
942 | old_dir->i_version++; | |
943 | old_dir->i_ctime = old_dir->i_mtime = ts; | |
944 | if (IS_DIRSYNC(old_dir)) | |
945 | (void)fat_sync_inode(old_dir); | |
946 | else | |
947 | mark_inode_dirty(old_dir); | |
948 | ||
949 | if (new_inode) { | |
950 | if (is_dir) | |
951 | new_inode->i_nlink -= 2; | |
952 | else | |
953 | new_inode->i_nlink--; | |
954 | new_inode->i_ctime = ts; | |
955 | } | |
956 | out: | |
957 | brelse(sinfo.bh); | |
958 | brelse(dotdot_bh); | |
959 | brelse(old_sinfo.bh); | |
960 | unlock_kernel(); | |
961 | ||
962 | return err; | |
963 | ||
964 | error_dotdot: | |
965 | /* data cluster is shared, serious corruption */ | |
966 | corrupt = 1; | |
967 | ||
968 | if (update_dotdot) { | |
969 | int start = MSDOS_I(old_dir)->i_logstart; | |
970 | dotdot_de->start = cpu_to_le16(start); | |
971 | dotdot_de->starthi = cpu_to_le16(start >> 16); | |
972 | mark_buffer_dirty(dotdot_bh); | |
973 | corrupt |= sync_dirty_buffer(dotdot_bh); | |
974 | } | |
975 | error_inode: | |
976 | fat_detach(old_inode); | |
977 | fat_attach(old_inode, old_sinfo.i_pos); | |
978 | if (new_inode) { | |
9131dd42 | 979 | fat_attach(new_inode, new_i_pos); |
1da177e4 LT |
980 | if (corrupt) |
981 | corrupt |= fat_sync_inode(new_inode); | |
982 | } else { | |
983 | /* | |
984 | * If new entry was not sharing the data cluster, it | |
985 | * shouldn't be serious corruption. | |
986 | */ | |
987 | int err2 = fat_remove_entries(new_dir, &sinfo); | |
988 | if (corrupt) | |
989 | corrupt |= err2; | |
990 | sinfo.bh = NULL; | |
991 | } | |
992 | if (corrupt < 0) { | |
993 | fat_fs_panic(new_dir->i_sb, | |
994 | "%s: Filesystem corrupted (i_pos %lld)", | |
995 | __FUNCTION__, sinfo.i_pos); | |
996 | } | |
997 | goto out; | |
998 | } | |
999 | ||
1000 | static struct inode_operations vfat_dir_inode_operations = { | |
1001 | .create = vfat_create, | |
1002 | .lookup = vfat_lookup, | |
1003 | .unlink = vfat_unlink, | |
1004 | .mkdir = vfat_mkdir, | |
1005 | .rmdir = vfat_rmdir, | |
1006 | .rename = vfat_rename, | |
1007 | .setattr = fat_notify_change, | |
1008 | }; | |
1009 | ||
1010 | static int vfat_fill_super(struct super_block *sb, void *data, int silent) | |
1011 | { | |
1012 | int res; | |
1013 | ||
1014 | res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1); | |
1015 | if (res) | |
1016 | return res; | |
1017 | ||
1018 | if (MSDOS_SB(sb)->options.name_check != 's') | |
1019 | sb->s_root->d_op = &vfat_dentry_ops[0]; | |
1020 | else | |
1021 | sb->s_root->d_op = &vfat_dentry_ops[2]; | |
1022 | ||
1023 | return 0; | |
1024 | } | |
1025 | ||
1026 | static struct super_block *vfat_get_sb(struct file_system_type *fs_type, | |
1027 | int flags, const char *dev_name, | |
1028 | void *data) | |
1029 | { | |
1030 | return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super); | |
1031 | } | |
1032 | ||
1033 | static struct file_system_type vfat_fs_type = { | |
1034 | .owner = THIS_MODULE, | |
1035 | .name = "vfat", | |
1036 | .get_sb = vfat_get_sb, | |
1037 | .kill_sb = kill_block_super, | |
1038 | .fs_flags = FS_REQUIRES_DEV, | |
1039 | }; | |
1040 | ||
1041 | static int __init init_vfat_fs(void) | |
1042 | { | |
1043 | return register_filesystem(&vfat_fs_type); | |
1044 | } | |
1045 | ||
1046 | static void __exit exit_vfat_fs(void) | |
1047 | { | |
1048 | unregister_filesystem(&vfat_fs_type); | |
1049 | } | |
1050 | ||
1051 | MODULE_LICENSE("GPL"); | |
1052 | MODULE_DESCRIPTION("VFAT filesystem support"); | |
1053 | MODULE_AUTHOR("Gordon Chaffee"); | |
1054 | ||
1055 | module_init(init_vfat_fs) | |
1056 | module_exit(exit_vfat_fs) |