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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> | |
1da177e4 | 19 | #include <linux/jiffies.h> |
1da177e4 LT |
20 | #include <linux/ctype.h> |
21 | #include <linux/slab.h> | |
1da177e4 LT |
22 | #include <linux/buffer_head.h> |
23 | #include <linux/namei.h> | |
9e975dae | 24 | #include "fat.h" |
1da177e4 | 25 | |
1b524672 OH |
26 | /* |
27 | * If new entry was created in the parent, it could create the 8.3 | |
28 | * alias (the shortname of logname). So, the parent may have the | |
29 | * negative-dentry which matches the created 8.3 alias. | |
30 | * | |
31 | * If it happened, the negative dentry isn't actually negative | |
32 | * anymore. So, drop it. | |
33 | */ | |
34 | static int vfat_revalidate_shortname(struct dentry *dentry) | |
1da177e4 LT |
35 | { |
36 | int ret = 1; | |
1b524672 OH |
37 | spin_lock(&dentry->d_lock); |
38 | if (dentry->d_time != dentry->d_parent->d_inode->i_version) | |
1da177e4 | 39 | ret = 0; |
1b524672 | 40 | spin_unlock(&dentry->d_lock); |
1da177e4 LT |
41 | return ret; |
42 | } | |
43 | ||
0b728e19 | 44 | static int vfat_revalidate(struct dentry *dentry, unsigned int flags) |
1b524672 | 45 | { |
0b728e19 | 46 | if (flags & LOOKUP_RCU) |
34286d66 NP |
47 | return -ECHILD; |
48 | ||
1b524672 OH |
49 | /* This is not negative dentry. Always valid. */ |
50 | if (dentry->d_inode) | |
51 | return 1; | |
52 | return vfat_revalidate_shortname(dentry); | |
53 | } | |
54 | ||
0b728e19 | 55 | static int vfat_revalidate_ci(struct dentry *dentry, unsigned int flags) |
1b524672 | 56 | { |
0b728e19 | 57 | if (flags & LOOKUP_RCU) |
34286d66 NP |
58 | return -ECHILD; |
59 | ||
1b524672 OH |
60 | /* |
61 | * This is not negative dentry. Always valid. | |
62 | * | |
63 | * Note, rename() to existing directory entry will have ->d_inode, | |
64 | * and will use existing name which isn't specified name by user. | |
65 | * | |
66 | * We may be able to drop this positive dentry here. But dropping | |
67 | * positive dentry isn't good idea. So it's unsupported like | |
68 | * rename("filename", "FILENAME") for now. | |
69 | */ | |
70 | if (dentry->d_inode) | |
71 | return 1; | |
72 | ||
73 | /* | |
74 | * This may be nfsd (or something), anyway, we can't see the | |
75 | * intent of this. So, since this can be for creation, drop it. | |
76 | */ | |
0b728e19 | 77 | if (!flags) |
1b524672 OH |
78 | return 0; |
79 | ||
80 | /* | |
81 | * Drop the negative dentry, in order to make sure to use the | |
82 | * case sensitive name which is specified by user if this is | |
83 | * for creation. | |
84 | */ | |
0b728e19 | 85 | if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) |
407938e7 | 86 | return 0; |
1b524672 OH |
87 | |
88 | return vfat_revalidate_shortname(dentry); | |
89 | } | |
90 | ||
1da177e4 | 91 | /* returns the length of a struct qstr, ignoring trailing dots */ |
621e155a | 92 | static unsigned int __vfat_striptail_len(unsigned int len, const char *name) |
1da177e4 | 93 | { |
621e155a | 94 | while (len && name[len - 1] == '.') |
1da177e4 LT |
95 | len--; |
96 | return len; | |
97 | } | |
98 | ||
621e155a NP |
99 | static unsigned int vfat_striptail_len(const struct qstr *qstr) |
100 | { | |
101 | return __vfat_striptail_len(qstr->len, qstr->name); | |
102 | } | |
103 | ||
1da177e4 LT |
104 | /* |
105 | * Compute the hash for the vfat name corresponding to the dentry. | |
106 | * Note: if the name is invalid, we leave the hash code unchanged so | |
107 | * that the existing dentry can be used. The vfat fs routines will | |
108 | * return ENOENT or EINVAL as appropriate. | |
109 | */ | |
b1e6a015 NP |
110 | static int vfat_hash(const struct dentry *dentry, const struct inode *inode, |
111 | struct qstr *qstr) | |
1da177e4 LT |
112 | { |
113 | qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr)); | |
114 | return 0; | |
115 | } | |
116 | ||
117 | /* | |
118 | * Compute the hash for the vfat name corresponding to the dentry. | |
119 | * Note: if the name is invalid, we leave the hash code unchanged so | |
120 | * that the existing dentry can be used. The vfat fs routines will | |
121 | * return ENOENT or EINVAL as appropriate. | |
122 | */ | |
b1e6a015 NP |
123 | static int vfat_hashi(const struct dentry *dentry, const struct inode *inode, |
124 | struct qstr *qstr) | |
1da177e4 | 125 | { |
b1e6a015 | 126 | struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; |
1da177e4 LT |
127 | const unsigned char *name; |
128 | unsigned int len; | |
129 | unsigned long hash; | |
130 | ||
131 | name = qstr->name; | |
132 | len = vfat_striptail_len(qstr); | |
133 | ||
134 | hash = init_name_hash(); | |
135 | while (len--) | |
136 | hash = partial_name_hash(nls_tolower(t, *name++), hash); | |
137 | qstr->hash = end_name_hash(hash); | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | /* | |
143 | * Case insensitive compare of two vfat names. | |
144 | */ | |
621e155a NP |
145 | static int vfat_cmpi(const struct dentry *parent, const struct inode *pinode, |
146 | const struct dentry *dentry, const struct inode *inode, | |
147 | unsigned int len, const char *str, const struct qstr *name) | |
1da177e4 | 148 | { |
621e155a | 149 | struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io; |
1da177e4 LT |
150 | unsigned int alen, blen; |
151 | ||
152 | /* A filename cannot end in '.' or we treat it like it has none */ | |
621e155a NP |
153 | alen = vfat_striptail_len(name); |
154 | blen = __vfat_striptail_len(len, str); | |
1da177e4 | 155 | if (alen == blen) { |
621e155a | 156 | if (nls_strnicmp(t, name->name, str, alen) == 0) |
1da177e4 LT |
157 | return 0; |
158 | } | |
159 | return 1; | |
160 | } | |
161 | ||
162 | /* | |
163 | * Case sensitive compare of two vfat names. | |
164 | */ | |
621e155a NP |
165 | static int vfat_cmp(const struct dentry *parent, const struct inode *pinode, |
166 | const struct dentry *dentry, const struct inode *inode, | |
167 | unsigned int len, const char *str, const struct qstr *name) | |
1da177e4 LT |
168 | { |
169 | unsigned int alen, blen; | |
170 | ||
171 | /* A filename cannot end in '.' or we treat it like it has none */ | |
621e155a NP |
172 | alen = vfat_striptail_len(name); |
173 | blen = __vfat_striptail_len(len, str); | |
1da177e4 | 174 | if (alen == blen) { |
621e155a | 175 | if (strncmp(name->name, str, alen) == 0) |
1da177e4 LT |
176 | return 0; |
177 | } | |
178 | return 1; | |
179 | } | |
180 | ||
ce6cdc47 | 181 | static const struct dentry_operations vfat_ci_dentry_ops = { |
1b524672 OH |
182 | .d_revalidate = vfat_revalidate_ci, |
183 | .d_hash = vfat_hashi, | |
184 | .d_compare = vfat_cmpi, | |
185 | }; | |
186 | ||
ce6cdc47 | 187 | static const struct dentry_operations vfat_dentry_ops = { |
1b524672 OH |
188 | .d_revalidate = vfat_revalidate, |
189 | .d_hash = vfat_hash, | |
190 | .d_compare = vfat_cmp, | |
1da177e4 LT |
191 | }; |
192 | ||
193 | /* Characters that are undesirable in an MS-DOS file name */ | |
194 | ||
195 | static inline wchar_t vfat_bad_char(wchar_t w) | |
196 | { | |
197 | return (w < 0x0020) | |
198 | || (w == '*') || (w == '?') || (w == '<') || (w == '>') | |
199 | || (w == '|') || (w == '"') || (w == ':') || (w == '/') | |
200 | || (w == '\\'); | |
201 | } | |
202 | ||
203 | static inline wchar_t vfat_replace_char(wchar_t w) | |
204 | { | |
205 | return (w == '[') || (w == ']') || (w == ';') || (w == ',') | |
206 | || (w == '+') || (w == '='); | |
207 | } | |
208 | ||
209 | static wchar_t vfat_skip_char(wchar_t w) | |
210 | { | |
211 | return (w == '.') || (w == ' '); | |
212 | } | |
213 | ||
214 | static inline int vfat_is_used_badchars(const wchar_t *s, int len) | |
215 | { | |
216 | int i; | |
217 | ||
218 | for (i = 0; i < len; i++) | |
219 | if (vfat_bad_char(s[i])) | |
220 | return -EINVAL; | |
1da177e4 | 221 | |
f22032ba | 222 | if (s[i - 1] == ' ') /* last character cannot be space */ |
1da177e4 | 223 | return -EINVAL; |
f22032ba | 224 | |
1da177e4 LT |
225 | return 0; |
226 | } | |
227 | ||
228 | static int vfat_find_form(struct inode *dir, unsigned char *name) | |
229 | { | |
230 | struct fat_slot_info sinfo; | |
231 | int err = fat_scan(dir, name, &sinfo); | |
232 | if (err) | |
233 | return -ENOENT; | |
234 | brelse(sinfo.bh); | |
235 | return 0; | |
236 | } | |
237 | ||
238 | /* | |
239 | * 1) Valid characters for the 8.3 format alias are any combination of | |
240 | * letters, uppercase alphabets, digits, any of the | |
241 | * following special characters: | |
242 | * $ % ' ` - @ { } ~ ! # ( ) & _ ^ | |
243 | * In this case Longfilename is not stored in disk. | |
244 | * | |
245 | * WinNT's Extension: | |
246 | * File name and extension name is contain uppercase/lowercase | |
247 | * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT. | |
248 | * | |
249 | * 2) File name is 8.3 format, but it contain the uppercase and | |
250 | * lowercase char, muliti bytes char, etc. In this case numtail is not | |
251 | * added, but Longfilename is stored. | |
252 | * | |
253 | * 3) When the one except for the above, or the following special | |
254 | * character are contained: | |
255 | * . [ ] ; , + = | |
256 | * numtail is added, and Longfilename must be stored in disk . | |
257 | */ | |
258 | struct shortname_info { | |
259 | unsigned char lower:1, | |
260 | upper:1, | |
261 | valid:1; | |
262 | }; | |
263 | #define INIT_SHORTNAME_INFO(x) do { \ | |
264 | (x)->lower = 1; \ | |
265 | (x)->upper = 1; \ | |
266 | (x)->valid = 1; \ | |
267 | } while (0) | |
268 | ||
269 | static inline int to_shortname_char(struct nls_table *nls, | |
270 | unsigned char *buf, int buf_size, | |
271 | wchar_t *src, struct shortname_info *info) | |
272 | { | |
273 | int len; | |
274 | ||
275 | if (vfat_skip_char(*src)) { | |
276 | info->valid = 0; | |
277 | return 0; | |
278 | } | |
279 | if (vfat_replace_char(*src)) { | |
280 | info->valid = 0; | |
281 | buf[0] = '_'; | |
282 | return 1; | |
283 | } | |
284 | ||
285 | len = nls->uni2char(*src, buf, buf_size); | |
286 | if (len <= 0) { | |
287 | info->valid = 0; | |
288 | buf[0] = '_'; | |
289 | len = 1; | |
290 | } else if (len == 1) { | |
291 | unsigned char prev = buf[0]; | |
292 | ||
293 | if (buf[0] >= 0x7F) { | |
294 | info->lower = 0; | |
295 | info->upper = 0; | |
296 | } | |
297 | ||
298 | buf[0] = nls_toupper(nls, buf[0]); | |
299 | if (isalpha(buf[0])) { | |
300 | if (buf[0] == prev) | |
301 | info->lower = 0; | |
302 | else | |
303 | info->upper = 0; | |
304 | } | |
305 | } else { | |
306 | info->lower = 0; | |
307 | info->upper = 0; | |
308 | } | |
309 | ||
310 | return len; | |
311 | } | |
312 | ||
313 | /* | |
314 | * Given a valid longname, create a unique shortname. Make sure the | |
315 | * shortname does not exist | |
316 | * Returns negative number on error, 0 for a normal | |
317 | * return, and 1 for valid shortname | |
318 | */ | |
319 | static int vfat_create_shortname(struct inode *dir, struct nls_table *nls, | |
320 | wchar_t *uname, int ulen, | |
321 | unsigned char *name_res, unsigned char *lcase) | |
322 | { | |
323 | struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options; | |
324 | wchar_t *ip, *ext_start, *end, *name_start; | |
30d1872d | 325 | unsigned char base[9], ext[4], buf[5], *p; |
1da177e4 LT |
326 | unsigned char charbuf[NLS_MAX_CHARSET_SIZE]; |
327 | int chl, chi; | |
328 | int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen; | |
329 | int is_shortname; | |
330 | struct shortname_info base_info, ext_info; | |
331 | ||
332 | is_shortname = 1; | |
333 | INIT_SHORTNAME_INFO(&base_info); | |
334 | INIT_SHORTNAME_INFO(&ext_info); | |
335 | ||
336 | /* Now, we need to create a shortname from the long name */ | |
337 | ext_start = end = &uname[ulen]; | |
338 | while (--ext_start >= uname) { | |
339 | if (*ext_start == 0x002E) { /* is `.' */ | |
340 | if (ext_start == end - 1) { | |
341 | sz = ulen; | |
342 | ext_start = NULL; | |
343 | } | |
344 | break; | |
345 | } | |
346 | } | |
347 | ||
348 | if (ext_start == uname - 1) { | |
349 | sz = ulen; | |
350 | ext_start = NULL; | |
351 | } else if (ext_start) { | |
352 | /* | |
353 | * Names which start with a dot could be just | |
354 | * an extension eg. "...test". In this case Win95 | |
355 | * uses the extension as the name and sets no extension. | |
356 | */ | |
357 | name_start = &uname[0]; | |
358 | while (name_start < ext_start) { | |
359 | if (!vfat_skip_char(*name_start)) | |
360 | break; | |
361 | name_start++; | |
362 | } | |
363 | if (name_start != ext_start) { | |
364 | sz = ext_start - uname; | |
365 | ext_start++; | |
366 | } else { | |
367 | sz = ulen; | |
368 | ext_start = NULL; | |
369 | } | |
370 | } | |
371 | ||
372 | numtail_baselen = 6; | |
373 | numtail2_baselen = 2; | |
374 | for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) { | |
375 | chl = to_shortname_char(nls, charbuf, sizeof(charbuf), | |
376 | ip, &base_info); | |
377 | if (chl == 0) | |
378 | continue; | |
379 | ||
380 | if (baselen < 2 && (baselen + chl) > 2) | |
381 | numtail2_baselen = baselen; | |
382 | if (baselen < 6 && (baselen + chl) > 6) | |
383 | numtail_baselen = baselen; | |
384 | for (chi = 0; chi < chl; chi++) { | |
385 | *p++ = charbuf[chi]; | |
386 | baselen++; | |
387 | if (baselen >= 8) | |
388 | break; | |
389 | } | |
390 | if (baselen >= 8) { | |
391 | if ((chi < chl - 1) || (ip + 1) - uname < sz) | |
392 | is_shortname = 0; | |
393 | break; | |
394 | } | |
395 | } | |
396 | if (baselen == 0) { | |
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | extlen = 0; | |
401 | if (ext_start) { | |
402 | for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) { | |
403 | chl = to_shortname_char(nls, charbuf, sizeof(charbuf), | |
404 | ip, &ext_info); | |
405 | if (chl == 0) | |
406 | continue; | |
407 | ||
408 | if ((extlen + chl) > 3) { | |
409 | is_shortname = 0; | |
410 | break; | |
411 | } | |
412 | for (chi = 0; chi < chl; chi++) { | |
413 | *p++ = charbuf[chi]; | |
414 | extlen++; | |
415 | } | |
416 | if (extlen >= 3) { | |
417 | if (ip + 1 != end) | |
418 | is_shortname = 0; | |
419 | break; | |
420 | } | |
421 | } | |
422 | } | |
423 | ext[extlen] = '\0'; | |
424 | base[baselen] = '\0'; | |
425 | ||
426 | /* Yes, it can happen. ".\xe5" would do it. */ | |
427 | if (base[0] == DELETED_FLAG) | |
428 | base[0] = 0x05; | |
429 | ||
430 | /* OK, at this point we know that base is not longer than 8 symbols, | |
431 | * ext is not longer than 3, base is nonempty, both don't contain | |
432 | * any bad symbols (lowercase transformed to uppercase). | |
433 | */ | |
434 | ||
435 | memset(name_res, ' ', MSDOS_NAME); | |
436 | memcpy(name_res, base, baselen); | |
437 | memcpy(name_res + 8, ext, extlen); | |
438 | *lcase = 0; | |
439 | if (is_shortname && base_info.valid && ext_info.valid) { | |
440 | if (vfat_find_form(dir, name_res) == 0) | |
441 | return -EEXIST; | |
442 | ||
443 | if (opts->shortname & VFAT_SFN_CREATE_WIN95) { | |
444 | return (base_info.upper && ext_info.upper); | |
445 | } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) { | |
446 | if ((base_info.upper || base_info.lower) && | |
447 | (ext_info.upper || ext_info.lower)) { | |
448 | if (!base_info.upper && base_info.lower) | |
449 | *lcase |= CASE_LOWER_BASE; | |
450 | if (!ext_info.upper && ext_info.lower) | |
451 | *lcase |= CASE_LOWER_EXT; | |
452 | return 1; | |
453 | } | |
454 | return 0; | |
455 | } else { | |
456 | BUG(); | |
457 | } | |
458 | } | |
459 | ||
460 | if (opts->numtail == 0) | |
461 | if (vfat_find_form(dir, name_res) < 0) | |
462 | return 0; | |
463 | ||
464 | /* | |
465 | * Try to find a unique extension. This used to | |
466 | * iterate through all possibilities sequentially, | |
467 | * but that gave extremely bad performance. Windows | |
468 | * only tries a few cases before using random | |
469 | * values for part of the base. | |
470 | */ | |
471 | ||
472 | if (baselen > 6) { | |
473 | baselen = numtail_baselen; | |
474 | name_res[7] = ' '; | |
475 | } | |
476 | name_res[baselen] = '~'; | |
477 | for (i = 1; i < 10; i++) { | |
478 | name_res[baselen + 1] = i + '0'; | |
479 | if (vfat_find_form(dir, name_res) < 0) | |
480 | return 0; | |
481 | } | |
482 | ||
30d1872d | 483 | i = jiffies; |
1da177e4 LT |
484 | sz = (jiffies >> 16) & 0x7; |
485 | if (baselen > 2) { | |
486 | baselen = numtail2_baselen; | |
487 | name_res[7] = ' '; | |
488 | } | |
489 | name_res[baselen + 4] = '~'; | |
490 | name_res[baselen + 5] = '1' + sz; | |
491 | while (1) { | |
30d1872d | 492 | snprintf(buf, sizeof(buf), "%04X", i & 0xffff); |
1da177e4 LT |
493 | memcpy(&name_res[baselen], buf, 4); |
494 | if (vfat_find_form(dir, name_res) < 0) | |
495 | break; | |
496 | i -= 11; | |
497 | } | |
498 | return 0; | |
499 | } | |
500 | ||
501 | /* Translate a string, including coded sequences into Unicode */ | |
502 | static int | |
503 | xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, | |
504 | int *longlen, int *outlen, int escape, int utf8, | |
505 | struct nls_table *nls) | |
506 | { | |
507 | const unsigned char *ip; | |
508 | unsigned char nc; | |
509 | unsigned char *op; | |
510 | unsigned int ec; | |
511 | int i, k, fill; | |
512 | int charlen; | |
513 | ||
514 | if (utf8) { | |
0720a06a AS |
515 | *outlen = utf8s_to_utf16s(name, len, UTF16_HOST_ENDIAN, |
516 | (wchar_t *) outname, FAT_LFN_LEN + 2); | |
67638e40 OH |
517 | if (*outlen < 0) |
518 | return *outlen; | |
eeb5b4ae | 519 | else if (*outlen > FAT_LFN_LEN) |
f22032ba KM |
520 | return -ENAMETOOLONG; |
521 | ||
1da177e4 LT |
522 | op = &outname[*outlen * sizeof(wchar_t)]; |
523 | } else { | |
41f0c02e | 524 | for (i = 0, ip = name, op = outname, *outlen = 0; |
d533df07 | 525 | i < len && *outlen < FAT_LFN_LEN; |
41f0c02e NJ |
526 | *outlen += 1) { |
527 | if (escape && (*ip == ':')) { | |
528 | if (i > len - 5) | |
529 | return -EINVAL; | |
530 | ec = 0; | |
531 | for (k = 1; k < 5; k++) { | |
532 | nc = ip[k]; | |
533 | ec <<= 4; | |
534 | if (nc >= '0' && nc <= '9') { | |
535 | ec |= nc - '0'; | |
536 | continue; | |
1da177e4 | 537 | } |
41f0c02e NJ |
538 | if (nc >= 'a' && nc <= 'f') { |
539 | ec |= nc - ('a' - 10); | |
540 | continue; | |
541 | } | |
542 | if (nc >= 'A' && nc <= 'F') { | |
543 | ec |= nc - ('A' - 10); | |
544 | continue; | |
545 | } | |
546 | return -EINVAL; | |
1da177e4 | 547 | } |
41f0c02e NJ |
548 | *op++ = ec & 0xFF; |
549 | *op++ = ec >> 8; | |
550 | ip += 5; | |
551 | i += 5; | |
552 | } else { | |
553 | charlen = nls->char2uni(ip, len - i, | |
554 | (wchar_t *)op); | |
555 | if (charlen < 0) | |
556 | return -EINVAL; | |
557 | ip += charlen; | |
558 | i += charlen; | |
559 | op += 2; | |
1da177e4 | 560 | } |
1da177e4 | 561 | } |
41f0c02e NJ |
562 | if (i < len) |
563 | return -ENAMETOOLONG; | |
1da177e4 | 564 | } |
1da177e4 LT |
565 | |
566 | *longlen = *outlen; | |
567 | if (*outlen % 13) { | |
568 | *op++ = 0; | |
569 | *op++ = 0; | |
570 | *outlen += 1; | |
571 | if (*outlen % 13) { | |
572 | fill = 13 - (*outlen % 13); | |
573 | for (i = 0; i < fill; i++) { | |
574 | *op++ = 0xff; | |
575 | *op++ = 0xff; | |
576 | } | |
577 | *outlen += fill; | |
578 | } | |
579 | } | |
580 | ||
581 | return 0; | |
582 | } | |
583 | ||
584 | static int vfat_build_slots(struct inode *dir, const unsigned char *name, | |
585 | int len, int is_dir, int cluster, | |
586 | struct timespec *ts, | |
587 | struct msdos_dir_slot *slots, int *nr_slots) | |
588 | { | |
589 | struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); | |
590 | struct fat_mount_options *opts = &sbi->options; | |
591 | struct msdos_dir_slot *ps; | |
592 | struct msdos_dir_entry *de; | |
1da177e4 LT |
593 | unsigned char cksum, lcase; |
594 | unsigned char msdos_name[MSDOS_NAME]; | |
595 | wchar_t *uname; | |
596 | __le16 time, date; | |
7decd1cb | 597 | u8 time_cs; |
1da177e4 LT |
598 | int err, ulen, usize, i; |
599 | loff_t offset; | |
600 | ||
601 | *nr_slots = 0; | |
1da177e4 | 602 | |
c7a6c4ed OH |
603 | uname = __getname(); |
604 | if (!uname) | |
1da177e4 LT |
605 | return -ENOMEM; |
606 | ||
1da177e4 LT |
607 | err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize, |
608 | opts->unicode_xlate, opts->utf8, sbi->nls_io); | |
609 | if (err) | |
610 | goto out_free; | |
611 | ||
612 | err = vfat_is_used_badchars(uname, ulen); | |
613 | if (err) | |
614 | goto out_free; | |
615 | ||
616 | err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen, | |
617 | msdos_name, &lcase); | |
618 | if (err < 0) | |
619 | goto out_free; | |
620 | else if (err == 1) { | |
621 | de = (struct msdos_dir_entry *)slots; | |
622 | err = 0; | |
623 | goto shortname; | |
624 | } | |
625 | ||
626 | /* build the entry of long file name */ | |
451cbaa1 | 627 | cksum = fat_checksum(msdos_name); |
1da177e4 LT |
628 | |
629 | *nr_slots = usize / 13; | |
630 | for (ps = slots, i = *nr_slots; i > 0; i--, ps++) { | |
631 | ps->id = i; | |
632 | ps->attr = ATTR_EXT; | |
633 | ps->reserved = 0; | |
634 | ps->alias_checksum = cksum; | |
635 | ps->start = 0; | |
636 | offset = (i - 1) * 13; | |
637 | fatwchar_to16(ps->name0_4, uname + offset, 5); | |
638 | fatwchar_to16(ps->name5_10, uname + offset + 5, 6); | |
639 | fatwchar_to16(ps->name11_12, uname + offset + 11, 2); | |
640 | } | |
641 | slots[0].id |= 0x40; | |
642 | de = (struct msdos_dir_entry *)ps; | |
643 | ||
644 | shortname: | |
645 | /* build the entry of 8.3 alias name */ | |
646 | (*nr_slots)++; | |
647 | memcpy(de->name, msdos_name, MSDOS_NAME); | |
648 | de->attr = is_dir ? ATTR_DIR : ATTR_ARCH; | |
649 | de->lcase = lcase; | |
7decd1cb | 650 | fat_time_unix2fat(sbi, ts, &time, &date, &time_cs); |
1da177e4 LT |
651 | de->time = de->ctime = time; |
652 | de->date = de->cdate = de->adate = date; | |
7decd1cb | 653 | de->ctime_cs = time_cs; |
a943ed71 | 654 | fat_set_start(de, cluster); |
1da177e4 LT |
655 | de->size = 0; |
656 | out_free: | |
c7a6c4ed | 657 | __putname(uname); |
1da177e4 LT |
658 | return err; |
659 | } | |
660 | ||
661 | static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir, | |
662 | int cluster, struct timespec *ts, | |
663 | struct fat_slot_info *sinfo) | |
664 | { | |
665 | struct msdos_dir_slot *slots; | |
666 | unsigned int len; | |
667 | int err, nr_slots; | |
668 | ||
669 | len = vfat_striptail_len(qname); | |
670 | if (len == 0) | |
671 | return -ENOENT; | |
672 | ||
8f593427 | 673 | slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS); |
1da177e4 LT |
674 | if (slots == NULL) |
675 | return -ENOMEM; | |
676 | ||
677 | err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts, | |
678 | slots, &nr_slots); | |
679 | if (err) | |
680 | goto cleanup; | |
681 | ||
682 | err = fat_add_entries(dir, slots, nr_slots, sinfo); | |
683 | if (err) | |
684 | goto cleanup; | |
685 | ||
686 | /* update timestamp */ | |
687 | dir->i_ctime = dir->i_mtime = dir->i_atime = *ts; | |
688 | if (IS_DIRSYNC(dir)) | |
689 | (void)fat_sync_inode(dir); | |
690 | else | |
691 | mark_inode_dirty(dir); | |
692 | cleanup: | |
693 | kfree(slots); | |
694 | return err; | |
695 | } | |
696 | ||
697 | static int vfat_find(struct inode *dir, struct qstr *qname, | |
698 | struct fat_slot_info *sinfo) | |
699 | { | |
700 | unsigned int len = vfat_striptail_len(qname); | |
701 | if (len == 0) | |
702 | return -ENOENT; | |
703 | return fat_search_long(dir, qname->name, len, sinfo); | |
704 | } | |
705 | ||
8045e298 OH |
706 | /* |
707 | * (nfsd's) anonymous disconnected dentry? | |
708 | * NOTE: !IS_ROOT() is not anonymous (I.e. d_splice_alias() did the job). | |
709 | */ | |
710 | static int vfat_d_anon_disconn(struct dentry *dentry) | |
711 | { | |
712 | return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED); | |
713 | } | |
714 | ||
1da177e4 | 715 | static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, |
00cd8dd3 | 716 | unsigned int flags) |
1da177e4 LT |
717 | { |
718 | struct super_block *sb = dir->i_sb; | |
719 | struct fat_slot_info sinfo; | |
068f5ae0 | 720 | struct inode *inode; |
1da177e4 | 721 | struct dentry *alias; |
1b524672 | 722 | int err; |
1da177e4 | 723 | |
e40b34c7 | 724 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
725 | |
726 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
727 | if (err) { | |
068f5ae0 | 728 | if (err == -ENOENT) { |
068f5ae0 OH |
729 | inode = NULL; |
730 | goto out; | |
731 | } | |
1da177e4 LT |
732 | goto error; |
733 | } | |
1b524672 | 734 | |
1da177e4 LT |
735 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); |
736 | brelse(sinfo.bh); | |
737 | if (IS_ERR(inode)) { | |
068f5ae0 OH |
738 | err = PTR_ERR(inode); |
739 | goto error; | |
1da177e4 | 740 | } |
1b524672 | 741 | |
1da177e4 | 742 | alias = d_find_alias(inode); |
8045e298 | 743 | if (alias && !vfat_d_anon_disconn(alias)) { |
1b524672 | 744 | /* |
8045e298 OH |
745 | * This inode has non anonymous-DCACHE_DISCONNECTED |
746 | * dentry. This means, the user did ->lookup() by an | |
747 | * another name (longname vs 8.3 alias of it) in past. | |
1b524672 OH |
748 | * |
749 | * Switch to new one for reason of locality if possible. | |
750 | */ | |
1c13a243 OH |
751 | BUG_ON(d_unhashed(alias)); |
752 | if (!S_ISDIR(inode->i_mode)) | |
753 | d_move(alias, dentry); | |
754 | iput(inode); | |
e40b34c7 | 755 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1c13a243 | 756 | return alias; |
8045e298 OH |
757 | } else |
758 | dput(alias); | |
759 | ||
068f5ae0 | 760 | out: |
e40b34c7 | 761 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
762 | dentry->d_time = dentry->d_parent->d_inode->i_version; |
763 | dentry = d_splice_alias(inode, dentry); | |
3d23985d | 764 | if (dentry) |
1da177e4 | 765 | dentry->d_time = dentry->d_parent->d_inode->i_version; |
1da177e4 | 766 | return dentry; |
068f5ae0 OH |
767 | |
768 | error: | |
e40b34c7 | 769 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
068f5ae0 | 770 | return ERR_PTR(err); |
1da177e4 LT |
771 | } |
772 | ||
4acdaf27 | 773 | static int vfat_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
ebfc3b49 | 774 | bool excl) |
1da177e4 LT |
775 | { |
776 | struct super_block *sb = dir->i_sb; | |
777 | struct inode *inode; | |
778 | struct fat_slot_info sinfo; | |
779 | struct timespec ts; | |
780 | int err; | |
781 | ||
e40b34c7 | 782 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
783 | |
784 | ts = CURRENT_TIME_SEC; | |
785 | err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo); | |
786 | if (err) | |
787 | goto out; | |
788 | dir->i_version++; | |
789 | ||
790 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
791 | brelse(sinfo.bh); | |
792 | if (IS_ERR(inode)) { | |
793 | err = PTR_ERR(inode); | |
794 | goto out; | |
795 | } | |
796 | inode->i_version++; | |
797 | inode->i_mtime = inode->i_atime = inode->i_ctime = ts; | |
798 | /* timestamp is already written, so mark_inode_dirty() is unneeded. */ | |
799 | ||
800 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
801 | d_instantiate(dentry, inode); | |
802 | out: | |
e40b34c7 | 803 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
804 | return err; |
805 | } | |
806 | ||
807 | static int vfat_rmdir(struct inode *dir, struct dentry *dentry) | |
808 | { | |
809 | struct inode *inode = dentry->d_inode; | |
8f593427 | 810 | struct super_block *sb = dir->i_sb; |
1da177e4 LT |
811 | struct fat_slot_info sinfo; |
812 | int err; | |
813 | ||
e40b34c7 | 814 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
815 | |
816 | err = fat_dir_empty(inode); | |
817 | if (err) | |
818 | goto out; | |
819 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
820 | if (err) | |
821 | goto out; | |
822 | ||
823 | err = fat_remove_entries(dir, &sinfo); /* and releases bh */ | |
824 | if (err) | |
825 | goto out; | |
9a53c3a7 | 826 | drop_nlink(dir); |
1da177e4 | 827 | |
ce71ec36 | 828 | clear_nlink(inode); |
1da177e4 LT |
829 | inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; |
830 | fat_detach(inode); | |
831 | out: | |
e40b34c7 | 832 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
833 | |
834 | return err; | |
835 | } | |
836 | ||
837 | static int vfat_unlink(struct inode *dir, struct dentry *dentry) | |
838 | { | |
839 | struct inode *inode = dentry->d_inode; | |
8f593427 | 840 | struct super_block *sb = dir->i_sb; |
1da177e4 LT |
841 | struct fat_slot_info sinfo; |
842 | int err; | |
843 | ||
e40b34c7 | 844 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
845 | |
846 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
847 | if (err) | |
848 | goto out; | |
849 | ||
850 | err = fat_remove_entries(dir, &sinfo); /* and releases bh */ | |
851 | if (err) | |
852 | goto out; | |
ce71ec36 | 853 | clear_nlink(inode); |
1da177e4 LT |
854 | inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; |
855 | fat_detach(inode); | |
856 | out: | |
e40b34c7 | 857 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
858 | |
859 | return err; | |
860 | } | |
861 | ||
18bb1db3 | 862 | static int vfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
863 | { |
864 | struct super_block *sb = dir->i_sb; | |
865 | struct inode *inode; | |
866 | struct fat_slot_info sinfo; | |
867 | struct timespec ts; | |
868 | int err, cluster; | |
869 | ||
e40b34c7 | 870 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
871 | |
872 | ts = CURRENT_TIME_SEC; | |
873 | cluster = fat_alloc_new_dir(dir, &ts); | |
874 | if (cluster < 0) { | |
875 | err = cluster; | |
876 | goto out; | |
877 | } | |
878 | err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo); | |
879 | if (err) | |
880 | goto out_free; | |
881 | dir->i_version++; | |
d8c76e6f | 882 | inc_nlink(dir); |
1da177e4 LT |
883 | |
884 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
885 | brelse(sinfo.bh); | |
886 | if (IS_ERR(inode)) { | |
887 | err = PTR_ERR(inode); | |
888 | /* the directory was completed, just return a error */ | |
889 | goto out; | |
890 | } | |
891 | inode->i_version++; | |
bfe86848 | 892 | set_nlink(inode, 2); |
1da177e4 LT |
893 | inode->i_mtime = inode->i_atime = inode->i_ctime = ts; |
894 | /* timestamp is already written, so mark_inode_dirty() is unneeded. */ | |
895 | ||
896 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
897 | d_instantiate(dentry, inode); | |
898 | ||
e40b34c7 | 899 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
900 | return 0; |
901 | ||
902 | out_free: | |
903 | fat_free_clusters(dir, cluster); | |
904 | out: | |
e40b34c7 | 905 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
906 | return err; |
907 | } | |
908 | ||
909 | static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, | |
910 | struct inode *new_dir, struct dentry *new_dentry) | |
911 | { | |
912 | struct buffer_head *dotdot_bh; | |
913 | struct msdos_dir_entry *dotdot_de; | |
1da177e4 LT |
914 | struct inode *old_inode, *new_inode; |
915 | struct fat_slot_info old_sinfo, sinfo; | |
916 | struct timespec ts; | |
7669e8fb | 917 | loff_t new_i_pos; |
1da177e4 | 918 | int err, is_dir, update_dotdot, corrupt = 0; |
8f593427 | 919 | struct super_block *sb = old_dir->i_sb; |
1da177e4 LT |
920 | |
921 | old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; | |
922 | old_inode = old_dentry->d_inode; | |
923 | new_inode = new_dentry->d_inode; | |
e40b34c7 | 924 | mutex_lock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
925 | err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo); |
926 | if (err) | |
927 | goto out; | |
928 | ||
929 | is_dir = S_ISDIR(old_inode->i_mode); | |
930 | update_dotdot = (is_dir && old_dir != new_dir); | |
931 | if (update_dotdot) { | |
7669e8fb | 932 | if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) { |
1da177e4 LT |
933 | err = -EIO; |
934 | goto out; | |
935 | } | |
936 | } | |
937 | ||
938 | ts = CURRENT_TIME_SEC; | |
939 | if (new_inode) { | |
1da177e4 LT |
940 | if (is_dir) { |
941 | err = fat_dir_empty(new_inode); | |
942 | if (err) | |
943 | goto out; | |
944 | } | |
9131dd42 | 945 | new_i_pos = MSDOS_I(new_inode)->i_pos; |
1da177e4 LT |
946 | fat_detach(new_inode); |
947 | } else { | |
948 | err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0, | |
949 | &ts, &sinfo); | |
950 | if (err) | |
951 | goto out; | |
9131dd42 | 952 | new_i_pos = sinfo.i_pos; |
1da177e4 LT |
953 | } |
954 | new_dir->i_version++; | |
955 | ||
956 | fat_detach(old_inode); | |
9131dd42 | 957 | fat_attach(old_inode, new_i_pos); |
1da177e4 LT |
958 | if (IS_DIRSYNC(new_dir)) { |
959 | err = fat_sync_inode(old_inode); | |
960 | if (err) | |
961 | goto error_inode; | |
962 | } else | |
963 | mark_inode_dirty(old_inode); | |
964 | ||
965 | if (update_dotdot) { | |
a943ed71 | 966 | fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart); |
b522412a | 967 | mark_buffer_dirty_inode(dotdot_bh, old_inode); |
1da177e4 LT |
968 | if (IS_DIRSYNC(new_dir)) { |
969 | err = sync_dirty_buffer(dotdot_bh); | |
970 | if (err) | |
971 | goto error_dotdot; | |
972 | } | |
9a53c3a7 | 973 | drop_nlink(old_dir); |
1da177e4 | 974 | if (!new_inode) |
d8c76e6f | 975 | inc_nlink(new_dir); |
1da177e4 LT |
976 | } |
977 | ||
978 | err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ | |
979 | old_sinfo.bh = NULL; | |
980 | if (err) | |
981 | goto error_dotdot; | |
982 | old_dir->i_version++; | |
983 | old_dir->i_ctime = old_dir->i_mtime = ts; | |
984 | if (IS_DIRSYNC(old_dir)) | |
985 | (void)fat_sync_inode(old_dir); | |
986 | else | |
987 | mark_inode_dirty(old_dir); | |
988 | ||
989 | if (new_inode) { | |
9a53c3a7 | 990 | drop_nlink(new_inode); |
1da177e4 | 991 | if (is_dir) |
9a53c3a7 | 992 | drop_nlink(new_inode); |
1da177e4 LT |
993 | new_inode->i_ctime = ts; |
994 | } | |
995 | out: | |
996 | brelse(sinfo.bh); | |
997 | brelse(dotdot_bh); | |
998 | brelse(old_sinfo.bh); | |
e40b34c7 | 999 | mutex_unlock(&MSDOS_SB(sb)->s_lock); |
1da177e4 LT |
1000 | |
1001 | return err; | |
1002 | ||
1003 | error_dotdot: | |
1004 | /* data cluster is shared, serious corruption */ | |
1005 | corrupt = 1; | |
1006 | ||
1007 | if (update_dotdot) { | |
a943ed71 | 1008 | fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart); |
b522412a | 1009 | mark_buffer_dirty_inode(dotdot_bh, old_inode); |
1da177e4 LT |
1010 | corrupt |= sync_dirty_buffer(dotdot_bh); |
1011 | } | |
1012 | error_inode: | |
1013 | fat_detach(old_inode); | |
1014 | fat_attach(old_inode, old_sinfo.i_pos); | |
1015 | if (new_inode) { | |
9131dd42 | 1016 | fat_attach(new_inode, new_i_pos); |
1da177e4 LT |
1017 | if (corrupt) |
1018 | corrupt |= fat_sync_inode(new_inode); | |
1019 | } else { | |
1020 | /* | |
1021 | * If new entry was not sharing the data cluster, it | |
1022 | * shouldn't be serious corruption. | |
1023 | */ | |
1024 | int err2 = fat_remove_entries(new_dir, &sinfo); | |
1025 | if (corrupt) | |
1026 | corrupt |= err2; | |
1027 | sinfo.bh = NULL; | |
1028 | } | |
1029 | if (corrupt < 0) { | |
85c78591 | 1030 | fat_fs_error(new_dir->i_sb, |
1da177e4 | 1031 | "%s: Filesystem corrupted (i_pos %lld)", |
8e24eea7 | 1032 | __func__, sinfo.i_pos); |
1da177e4 LT |
1033 | } |
1034 | goto out; | |
1035 | } | |
1036 | ||
c5ef1c42 | 1037 | static const struct inode_operations vfat_dir_inode_operations = { |
1da177e4 LT |
1038 | .create = vfat_create, |
1039 | .lookup = vfat_lookup, | |
1040 | .unlink = vfat_unlink, | |
1041 | .mkdir = vfat_mkdir, | |
1042 | .rmdir = vfat_rmdir, | |
1043 | .rename = vfat_rename, | |
1278fdd3 | 1044 | .setattr = fat_setattr, |
da63fc7c | 1045 | .getattr = fat_getattr, |
1da177e4 LT |
1046 | }; |
1047 | ||
3d23985d | 1048 | static void setup(struct super_block *sb) |
1da177e4 | 1049 | { |
384f5c96 | 1050 | MSDOS_SB(sb)->dir_ops = &vfat_dir_inode_operations; |
1da177e4 | 1051 | if (MSDOS_SB(sb)->options.name_check != 's') |
3d23985d | 1052 | sb->s_d_op = &vfat_ci_dentry_ops; |
1da177e4 | 1053 | else |
3d23985d AV |
1054 | sb->s_d_op = &vfat_dentry_ops; |
1055 | } | |
1da177e4 | 1056 | |
3d23985d AV |
1057 | static int vfat_fill_super(struct super_block *sb, void *data, int silent) |
1058 | { | |
384f5c96 | 1059 | return fat_fill_super(sb, data, silent, 1, setup); |
1da177e4 LT |
1060 | } |
1061 | ||
152a0836 | 1062 | static struct dentry *vfat_mount(struct file_system_type *fs_type, |
454e2398 | 1063 | int flags, const char *dev_name, |
152a0836 | 1064 | void *data) |
1da177e4 | 1065 | { |
152a0836 | 1066 | return mount_bdev(fs_type, flags, dev_name, data, vfat_fill_super); |
1da177e4 LT |
1067 | } |
1068 | ||
1069 | static struct file_system_type vfat_fs_type = { | |
1070 | .owner = THIS_MODULE, | |
1071 | .name = "vfat", | |
152a0836 | 1072 | .mount = vfat_mount, |
1da177e4 LT |
1073 | .kill_sb = kill_block_super, |
1074 | .fs_flags = FS_REQUIRES_DEV, | |
1075 | }; | |
7f78e035 | 1076 | MODULE_ALIAS_FS("vfat"); |
1da177e4 LT |
1077 | |
1078 | static int __init init_vfat_fs(void) | |
1079 | { | |
1080 | return register_filesystem(&vfat_fs_type); | |
1081 | } | |
1082 | ||
1083 | static void __exit exit_vfat_fs(void) | |
1084 | { | |
1085 | unregister_filesystem(&vfat_fs_type); | |
1086 | } | |
1087 | ||
1088 | MODULE_LICENSE("GPL"); | |
1089 | MODULE_DESCRIPTION("VFAT filesystem support"); | |
1090 | MODULE_AUTHOR("Gordon Chaffee"); | |
1091 | ||
1092 | module_init(init_vfat_fs) | |
1093 | module_exit(exit_vfat_fs) |