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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 | ||
1b524672 OH |
44 | static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd) |
45 | { | |
46 | /* This is not negative dentry. Always valid. */ | |
47 | if (dentry->d_inode) | |
48 | return 1; | |
49 | return vfat_revalidate_shortname(dentry); | |
50 | } | |
51 | ||
52 | static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd) | |
53 | { | |
54 | /* | |
55 | * This is not negative dentry. Always valid. | |
56 | * | |
57 | * Note, rename() to existing directory entry will have ->d_inode, | |
58 | * and will use existing name which isn't specified name by user. | |
59 | * | |
60 | * We may be able to drop this positive dentry here. But dropping | |
61 | * positive dentry isn't good idea. So it's unsupported like | |
62 | * rename("filename", "FILENAME") for now. | |
63 | */ | |
64 | if (dentry->d_inode) | |
65 | return 1; | |
66 | ||
67 | /* | |
68 | * This may be nfsd (or something), anyway, we can't see the | |
69 | * intent of this. So, since this can be for creation, drop it. | |
70 | */ | |
71 | if (!nd) | |
72 | return 0; | |
73 | ||
74 | /* | |
75 | * Drop the negative dentry, in order to make sure to use the | |
76 | * case sensitive name which is specified by user if this is | |
77 | * for creation. | |
78 | */ | |
79 | if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) { | |
ebeb0406 | 80 | if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) |
1b524672 OH |
81 | return 0; |
82 | } | |
83 | ||
84 | return vfat_revalidate_shortname(dentry); | |
85 | } | |
86 | ||
1da177e4 | 87 | /* returns the length of a struct qstr, ignoring trailing dots */ |
621e155a | 88 | static unsigned int __vfat_striptail_len(unsigned int len, const char *name) |
1da177e4 | 89 | { |
621e155a | 90 | while (len && name[len - 1] == '.') |
1da177e4 LT |
91 | len--; |
92 | return len; | |
93 | } | |
94 | ||
621e155a NP |
95 | static unsigned int vfat_striptail_len(const struct qstr *qstr) |
96 | { | |
97 | return __vfat_striptail_len(qstr->len, qstr->name); | |
98 | } | |
99 | ||
1da177e4 LT |
100 | /* |
101 | * Compute the hash for the vfat name corresponding to the dentry. | |
102 | * Note: if the name is invalid, we leave the hash code unchanged so | |
103 | * that the existing dentry can be used. The vfat fs routines will | |
104 | * return ENOENT or EINVAL as appropriate. | |
105 | */ | |
b1e6a015 NP |
106 | static int vfat_hash(const struct dentry *dentry, const struct inode *inode, |
107 | struct qstr *qstr) | |
1da177e4 LT |
108 | { |
109 | qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr)); | |
110 | return 0; | |
111 | } | |
112 | ||
113 | /* | |
114 | * Compute the hash for the vfat name corresponding to the dentry. | |
115 | * Note: if the name is invalid, we leave the hash code unchanged so | |
116 | * that the existing dentry can be used. The vfat fs routines will | |
117 | * return ENOENT or EINVAL as appropriate. | |
118 | */ | |
b1e6a015 NP |
119 | static int vfat_hashi(const struct dentry *dentry, const struct inode *inode, |
120 | struct qstr *qstr) | |
1da177e4 | 121 | { |
b1e6a015 | 122 | struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; |
1da177e4 LT |
123 | const unsigned char *name; |
124 | unsigned int len; | |
125 | unsigned long hash; | |
126 | ||
127 | name = qstr->name; | |
128 | len = vfat_striptail_len(qstr); | |
129 | ||
130 | hash = init_name_hash(); | |
131 | while (len--) | |
132 | hash = partial_name_hash(nls_tolower(t, *name++), hash); | |
133 | qstr->hash = end_name_hash(hash); | |
134 | ||
135 | return 0; | |
136 | } | |
137 | ||
138 | /* | |
139 | * Case insensitive compare of two vfat names. | |
140 | */ | |
621e155a NP |
141 | static int vfat_cmpi(const struct dentry *parent, const struct inode *pinode, |
142 | const struct dentry *dentry, const struct inode *inode, | |
143 | unsigned int len, const char *str, const struct qstr *name) | |
1da177e4 | 144 | { |
621e155a | 145 | struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io; |
1da177e4 LT |
146 | unsigned int alen, blen; |
147 | ||
148 | /* A filename cannot end in '.' or we treat it like it has none */ | |
621e155a NP |
149 | alen = vfat_striptail_len(name); |
150 | blen = __vfat_striptail_len(len, str); | |
1da177e4 | 151 | if (alen == blen) { |
621e155a | 152 | if (nls_strnicmp(t, name->name, str, alen) == 0) |
1da177e4 LT |
153 | return 0; |
154 | } | |
155 | return 1; | |
156 | } | |
157 | ||
158 | /* | |
159 | * Case sensitive compare of two vfat names. | |
160 | */ | |
621e155a NP |
161 | static int vfat_cmp(const struct dentry *parent, const struct inode *pinode, |
162 | const struct dentry *dentry, const struct inode *inode, | |
163 | unsigned int len, const char *str, const struct qstr *name) | |
1da177e4 LT |
164 | { |
165 | unsigned int alen, blen; | |
166 | ||
167 | /* A filename cannot end in '.' or we treat it like it has none */ | |
621e155a NP |
168 | alen = vfat_striptail_len(name); |
169 | blen = __vfat_striptail_len(len, str); | |
1da177e4 | 170 | if (alen == blen) { |
621e155a | 171 | if (strncmp(name->name, str, alen) == 0) |
1da177e4 LT |
172 | return 0; |
173 | } | |
174 | return 1; | |
175 | } | |
176 | ||
ce6cdc47 | 177 | static const struct dentry_operations vfat_ci_dentry_ops = { |
1b524672 OH |
178 | .d_revalidate = vfat_revalidate_ci, |
179 | .d_hash = vfat_hashi, | |
180 | .d_compare = vfat_cmpi, | |
181 | }; | |
182 | ||
ce6cdc47 | 183 | static const struct dentry_operations vfat_dentry_ops = { |
1b524672 OH |
184 | .d_revalidate = vfat_revalidate, |
185 | .d_hash = vfat_hash, | |
186 | .d_compare = vfat_cmp, | |
1da177e4 LT |
187 | }; |
188 | ||
189 | /* Characters that are undesirable in an MS-DOS file name */ | |
190 | ||
191 | static inline wchar_t vfat_bad_char(wchar_t w) | |
192 | { | |
193 | return (w < 0x0020) | |
194 | || (w == '*') || (w == '?') || (w == '<') || (w == '>') | |
195 | || (w == '|') || (w == '"') || (w == ':') || (w == '/') | |
196 | || (w == '\\'); | |
197 | } | |
198 | ||
199 | static inline wchar_t vfat_replace_char(wchar_t w) | |
200 | { | |
201 | return (w == '[') || (w == ']') || (w == ';') || (w == ',') | |
202 | || (w == '+') || (w == '='); | |
203 | } | |
204 | ||
205 | static wchar_t vfat_skip_char(wchar_t w) | |
206 | { | |
207 | return (w == '.') || (w == ' '); | |
208 | } | |
209 | ||
210 | static inline int vfat_is_used_badchars(const wchar_t *s, int len) | |
211 | { | |
212 | int i; | |
213 | ||
214 | for (i = 0; i < len; i++) | |
215 | if (vfat_bad_char(s[i])) | |
216 | return -EINVAL; | |
1da177e4 | 217 | |
f22032ba | 218 | if (s[i - 1] == ' ') /* last character cannot be space */ |
1da177e4 | 219 | return -EINVAL; |
f22032ba | 220 | |
1da177e4 LT |
221 | return 0; |
222 | } | |
223 | ||
224 | static int vfat_find_form(struct inode *dir, unsigned char *name) | |
225 | { | |
226 | struct fat_slot_info sinfo; | |
227 | int err = fat_scan(dir, name, &sinfo); | |
228 | if (err) | |
229 | return -ENOENT; | |
230 | brelse(sinfo.bh); | |
231 | return 0; | |
232 | } | |
233 | ||
234 | /* | |
235 | * 1) Valid characters for the 8.3 format alias are any combination of | |
236 | * letters, uppercase alphabets, digits, any of the | |
237 | * following special characters: | |
238 | * $ % ' ` - @ { } ~ ! # ( ) & _ ^ | |
239 | * In this case Longfilename is not stored in disk. | |
240 | * | |
241 | * WinNT's Extension: | |
242 | * File name and extension name is contain uppercase/lowercase | |
243 | * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT. | |
244 | * | |
245 | * 2) File name is 8.3 format, but it contain the uppercase and | |
246 | * lowercase char, muliti bytes char, etc. In this case numtail is not | |
247 | * added, but Longfilename is stored. | |
248 | * | |
249 | * 3) When the one except for the above, or the following special | |
250 | * character are contained: | |
251 | * . [ ] ; , + = | |
252 | * numtail is added, and Longfilename must be stored in disk . | |
253 | */ | |
254 | struct shortname_info { | |
255 | unsigned char lower:1, | |
256 | upper:1, | |
257 | valid:1; | |
258 | }; | |
259 | #define INIT_SHORTNAME_INFO(x) do { \ | |
260 | (x)->lower = 1; \ | |
261 | (x)->upper = 1; \ | |
262 | (x)->valid = 1; \ | |
263 | } while (0) | |
264 | ||
265 | static inline int to_shortname_char(struct nls_table *nls, | |
266 | unsigned char *buf, int buf_size, | |
267 | wchar_t *src, struct shortname_info *info) | |
268 | { | |
269 | int len; | |
270 | ||
271 | if (vfat_skip_char(*src)) { | |
272 | info->valid = 0; | |
273 | return 0; | |
274 | } | |
275 | if (vfat_replace_char(*src)) { | |
276 | info->valid = 0; | |
277 | buf[0] = '_'; | |
278 | return 1; | |
279 | } | |
280 | ||
281 | len = nls->uni2char(*src, buf, buf_size); | |
282 | if (len <= 0) { | |
283 | info->valid = 0; | |
284 | buf[0] = '_'; | |
285 | len = 1; | |
286 | } else if (len == 1) { | |
287 | unsigned char prev = buf[0]; | |
288 | ||
289 | if (buf[0] >= 0x7F) { | |
290 | info->lower = 0; | |
291 | info->upper = 0; | |
292 | } | |
293 | ||
294 | buf[0] = nls_toupper(nls, buf[0]); | |
295 | if (isalpha(buf[0])) { | |
296 | if (buf[0] == prev) | |
297 | info->lower = 0; | |
298 | else | |
299 | info->upper = 0; | |
300 | } | |
301 | } else { | |
302 | info->lower = 0; | |
303 | info->upper = 0; | |
304 | } | |
305 | ||
306 | return len; | |
307 | } | |
308 | ||
309 | /* | |
310 | * Given a valid longname, create a unique shortname. Make sure the | |
311 | * shortname does not exist | |
312 | * Returns negative number on error, 0 for a normal | |
313 | * return, and 1 for valid shortname | |
314 | */ | |
315 | static int vfat_create_shortname(struct inode *dir, struct nls_table *nls, | |
316 | wchar_t *uname, int ulen, | |
317 | unsigned char *name_res, unsigned char *lcase) | |
318 | { | |
319 | struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options; | |
320 | wchar_t *ip, *ext_start, *end, *name_start; | |
30d1872d | 321 | unsigned char base[9], ext[4], buf[5], *p; |
1da177e4 LT |
322 | unsigned char charbuf[NLS_MAX_CHARSET_SIZE]; |
323 | int chl, chi; | |
324 | int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen; | |
325 | int is_shortname; | |
326 | struct shortname_info base_info, ext_info; | |
327 | ||
328 | is_shortname = 1; | |
329 | INIT_SHORTNAME_INFO(&base_info); | |
330 | INIT_SHORTNAME_INFO(&ext_info); | |
331 | ||
332 | /* Now, we need to create a shortname from the long name */ | |
333 | ext_start = end = &uname[ulen]; | |
334 | while (--ext_start >= uname) { | |
335 | if (*ext_start == 0x002E) { /* is `.' */ | |
336 | if (ext_start == end - 1) { | |
337 | sz = ulen; | |
338 | ext_start = NULL; | |
339 | } | |
340 | break; | |
341 | } | |
342 | } | |
343 | ||
344 | if (ext_start == uname - 1) { | |
345 | sz = ulen; | |
346 | ext_start = NULL; | |
347 | } else if (ext_start) { | |
348 | /* | |
349 | * Names which start with a dot could be just | |
350 | * an extension eg. "...test". In this case Win95 | |
351 | * uses the extension as the name and sets no extension. | |
352 | */ | |
353 | name_start = &uname[0]; | |
354 | while (name_start < ext_start) { | |
355 | if (!vfat_skip_char(*name_start)) | |
356 | break; | |
357 | name_start++; | |
358 | } | |
359 | if (name_start != ext_start) { | |
360 | sz = ext_start - uname; | |
361 | ext_start++; | |
362 | } else { | |
363 | sz = ulen; | |
364 | ext_start = NULL; | |
365 | } | |
366 | } | |
367 | ||
368 | numtail_baselen = 6; | |
369 | numtail2_baselen = 2; | |
370 | for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) { | |
371 | chl = to_shortname_char(nls, charbuf, sizeof(charbuf), | |
372 | ip, &base_info); | |
373 | if (chl == 0) | |
374 | continue; | |
375 | ||
376 | if (baselen < 2 && (baselen + chl) > 2) | |
377 | numtail2_baselen = baselen; | |
378 | if (baselen < 6 && (baselen + chl) > 6) | |
379 | numtail_baselen = baselen; | |
380 | for (chi = 0; chi < chl; chi++) { | |
381 | *p++ = charbuf[chi]; | |
382 | baselen++; | |
383 | if (baselen >= 8) | |
384 | break; | |
385 | } | |
386 | if (baselen >= 8) { | |
387 | if ((chi < chl - 1) || (ip + 1) - uname < sz) | |
388 | is_shortname = 0; | |
389 | break; | |
390 | } | |
391 | } | |
392 | if (baselen == 0) { | |
393 | return -EINVAL; | |
394 | } | |
395 | ||
396 | extlen = 0; | |
397 | if (ext_start) { | |
398 | for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) { | |
399 | chl = to_shortname_char(nls, charbuf, sizeof(charbuf), | |
400 | ip, &ext_info); | |
401 | if (chl == 0) | |
402 | continue; | |
403 | ||
404 | if ((extlen + chl) > 3) { | |
405 | is_shortname = 0; | |
406 | break; | |
407 | } | |
408 | for (chi = 0; chi < chl; chi++) { | |
409 | *p++ = charbuf[chi]; | |
410 | extlen++; | |
411 | } | |
412 | if (extlen >= 3) { | |
413 | if (ip + 1 != end) | |
414 | is_shortname = 0; | |
415 | break; | |
416 | } | |
417 | } | |
418 | } | |
419 | ext[extlen] = '\0'; | |
420 | base[baselen] = '\0'; | |
421 | ||
422 | /* Yes, it can happen. ".\xe5" would do it. */ | |
423 | if (base[0] == DELETED_FLAG) | |
424 | base[0] = 0x05; | |
425 | ||
426 | /* OK, at this point we know that base is not longer than 8 symbols, | |
427 | * ext is not longer than 3, base is nonempty, both don't contain | |
428 | * any bad symbols (lowercase transformed to uppercase). | |
429 | */ | |
430 | ||
431 | memset(name_res, ' ', MSDOS_NAME); | |
432 | memcpy(name_res, base, baselen); | |
433 | memcpy(name_res + 8, ext, extlen); | |
434 | *lcase = 0; | |
435 | if (is_shortname && base_info.valid && ext_info.valid) { | |
436 | if (vfat_find_form(dir, name_res) == 0) | |
437 | return -EEXIST; | |
438 | ||
439 | if (opts->shortname & VFAT_SFN_CREATE_WIN95) { | |
440 | return (base_info.upper && ext_info.upper); | |
441 | } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) { | |
442 | if ((base_info.upper || base_info.lower) && | |
443 | (ext_info.upper || ext_info.lower)) { | |
444 | if (!base_info.upper && base_info.lower) | |
445 | *lcase |= CASE_LOWER_BASE; | |
446 | if (!ext_info.upper && ext_info.lower) | |
447 | *lcase |= CASE_LOWER_EXT; | |
448 | return 1; | |
449 | } | |
450 | return 0; | |
451 | } else { | |
452 | BUG(); | |
453 | } | |
454 | } | |
455 | ||
456 | if (opts->numtail == 0) | |
457 | if (vfat_find_form(dir, name_res) < 0) | |
458 | return 0; | |
459 | ||
460 | /* | |
461 | * Try to find a unique extension. This used to | |
462 | * iterate through all possibilities sequentially, | |
463 | * but that gave extremely bad performance. Windows | |
464 | * only tries a few cases before using random | |
465 | * values for part of the base. | |
466 | */ | |
467 | ||
468 | if (baselen > 6) { | |
469 | baselen = numtail_baselen; | |
470 | name_res[7] = ' '; | |
471 | } | |
472 | name_res[baselen] = '~'; | |
473 | for (i = 1; i < 10; i++) { | |
474 | name_res[baselen + 1] = i + '0'; | |
475 | if (vfat_find_form(dir, name_res) < 0) | |
476 | return 0; | |
477 | } | |
478 | ||
30d1872d | 479 | i = jiffies; |
1da177e4 LT |
480 | sz = (jiffies >> 16) & 0x7; |
481 | if (baselen > 2) { | |
482 | baselen = numtail2_baselen; | |
483 | name_res[7] = ' '; | |
484 | } | |
485 | name_res[baselen + 4] = '~'; | |
486 | name_res[baselen + 5] = '1' + sz; | |
487 | while (1) { | |
30d1872d | 488 | snprintf(buf, sizeof(buf), "%04X", i & 0xffff); |
1da177e4 LT |
489 | memcpy(&name_res[baselen], buf, 4); |
490 | if (vfat_find_form(dir, name_res) < 0) | |
491 | break; | |
492 | i -= 11; | |
493 | } | |
494 | return 0; | |
495 | } | |
496 | ||
497 | /* Translate a string, including coded sequences into Unicode */ | |
498 | static int | |
499 | xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, | |
500 | int *longlen, int *outlen, int escape, int utf8, | |
501 | struct nls_table *nls) | |
502 | { | |
503 | const unsigned char *ip; | |
504 | unsigned char nc; | |
505 | unsigned char *op; | |
506 | unsigned int ec; | |
507 | int i, k, fill; | |
508 | int charlen; | |
509 | ||
510 | if (utf8) { | |
67638e40 OH |
511 | *outlen = utf8s_to_utf16s(name, len, (wchar_t *)outname); |
512 | if (*outlen < 0) | |
513 | return *outlen; | |
eeb5b4ae | 514 | else if (*outlen > FAT_LFN_LEN) |
f22032ba KM |
515 | return -ENAMETOOLONG; |
516 | ||
1da177e4 LT |
517 | op = &outname[*outlen * sizeof(wchar_t)]; |
518 | } else { | |
519 | if (nls) { | |
520 | for (i = 0, ip = name, op = outname, *outlen = 0; | |
eeb5b4ae | 521 | i < len && *outlen <= FAT_LFN_LEN; |
1da177e4 LT |
522 | *outlen += 1) |
523 | { | |
524 | if (escape && (*ip == ':')) { | |
525 | if (i > len - 5) | |
526 | return -EINVAL; | |
527 | ec = 0; | |
528 | for (k = 1; k < 5; k++) { | |
529 | nc = ip[k]; | |
530 | ec <<= 4; | |
531 | if (nc >= '0' && nc <= '9') { | |
532 | ec |= nc - '0'; | |
533 | continue; | |
534 | } | |
535 | if (nc >= 'a' && nc <= 'f') { | |
536 | ec |= nc - ('a' - 10); | |
537 | continue; | |
538 | } | |
539 | if (nc >= 'A' && nc <= 'F') { | |
540 | ec |= nc - ('A' - 10); | |
541 | continue; | |
542 | } | |
543 | return -EINVAL; | |
544 | } | |
545 | *op++ = ec & 0xFF; | |
546 | *op++ = ec >> 8; | |
547 | ip += 5; | |
548 | i += 5; | |
549 | } else { | |
550 | if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0) | |
551 | return -EINVAL; | |
552 | ip += charlen; | |
553 | i += charlen; | |
554 | op += 2; | |
555 | } | |
556 | } | |
f22032ba KM |
557 | if (i < len) |
558 | return -ENAMETOOLONG; | |
1da177e4 LT |
559 | } else { |
560 | for (i = 0, ip = name, op = outname, *outlen = 0; | |
eeb5b4ae | 561 | i < len && *outlen <= FAT_LFN_LEN; |
1da177e4 LT |
562 | i++, *outlen += 1) |
563 | { | |
564 | *op++ = *ip++; | |
565 | *op++ = 0; | |
566 | } | |
f22032ba KM |
567 | if (i < len) |
568 | return -ENAMETOOLONG; | |
1da177e4 LT |
569 | } |
570 | } | |
1da177e4 LT |
571 | |
572 | *longlen = *outlen; | |
573 | if (*outlen % 13) { | |
574 | *op++ = 0; | |
575 | *op++ = 0; | |
576 | *outlen += 1; | |
577 | if (*outlen % 13) { | |
578 | fill = 13 - (*outlen % 13); | |
579 | for (i = 0; i < fill; i++) { | |
580 | *op++ = 0xff; | |
581 | *op++ = 0xff; | |
582 | } | |
583 | *outlen += fill; | |
584 | } | |
585 | } | |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
590 | static int vfat_build_slots(struct inode *dir, const unsigned char *name, | |
591 | int len, int is_dir, int cluster, | |
592 | struct timespec *ts, | |
593 | struct msdos_dir_slot *slots, int *nr_slots) | |
594 | { | |
595 | struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); | |
596 | struct fat_mount_options *opts = &sbi->options; | |
597 | struct msdos_dir_slot *ps; | |
598 | struct msdos_dir_entry *de; | |
1da177e4 LT |
599 | unsigned char cksum, lcase; |
600 | unsigned char msdos_name[MSDOS_NAME]; | |
601 | wchar_t *uname; | |
602 | __le16 time, date; | |
7decd1cb | 603 | u8 time_cs; |
1da177e4 LT |
604 | int err, ulen, usize, i; |
605 | loff_t offset; | |
606 | ||
607 | *nr_slots = 0; | |
1da177e4 | 608 | |
c7a6c4ed OH |
609 | uname = __getname(); |
610 | if (!uname) | |
1da177e4 LT |
611 | return -ENOMEM; |
612 | ||
1da177e4 LT |
613 | err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize, |
614 | opts->unicode_xlate, opts->utf8, sbi->nls_io); | |
615 | if (err) | |
616 | goto out_free; | |
617 | ||
618 | err = vfat_is_used_badchars(uname, ulen); | |
619 | if (err) | |
620 | goto out_free; | |
621 | ||
622 | err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen, | |
623 | msdos_name, &lcase); | |
624 | if (err < 0) | |
625 | goto out_free; | |
626 | else if (err == 1) { | |
627 | de = (struct msdos_dir_entry *)slots; | |
628 | err = 0; | |
629 | goto shortname; | |
630 | } | |
631 | ||
632 | /* build the entry of long file name */ | |
451cbaa1 | 633 | cksum = fat_checksum(msdos_name); |
1da177e4 LT |
634 | |
635 | *nr_slots = usize / 13; | |
636 | for (ps = slots, i = *nr_slots; i > 0; i--, ps++) { | |
637 | ps->id = i; | |
638 | ps->attr = ATTR_EXT; | |
639 | ps->reserved = 0; | |
640 | ps->alias_checksum = cksum; | |
641 | ps->start = 0; | |
642 | offset = (i - 1) * 13; | |
643 | fatwchar_to16(ps->name0_4, uname + offset, 5); | |
644 | fatwchar_to16(ps->name5_10, uname + offset + 5, 6); | |
645 | fatwchar_to16(ps->name11_12, uname + offset + 11, 2); | |
646 | } | |
647 | slots[0].id |= 0x40; | |
648 | de = (struct msdos_dir_entry *)ps; | |
649 | ||
650 | shortname: | |
651 | /* build the entry of 8.3 alias name */ | |
652 | (*nr_slots)++; | |
653 | memcpy(de->name, msdos_name, MSDOS_NAME); | |
654 | de->attr = is_dir ? ATTR_DIR : ATTR_ARCH; | |
655 | de->lcase = lcase; | |
7decd1cb | 656 | fat_time_unix2fat(sbi, ts, &time, &date, &time_cs); |
1da177e4 LT |
657 | de->time = de->ctime = time; |
658 | de->date = de->cdate = de->adate = date; | |
7decd1cb | 659 | de->ctime_cs = time_cs; |
1da177e4 LT |
660 | de->start = cpu_to_le16(cluster); |
661 | de->starthi = cpu_to_le16(cluster >> 16); | |
662 | de->size = 0; | |
663 | out_free: | |
c7a6c4ed | 664 | __putname(uname); |
1da177e4 LT |
665 | return err; |
666 | } | |
667 | ||
668 | static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir, | |
669 | int cluster, struct timespec *ts, | |
670 | struct fat_slot_info *sinfo) | |
671 | { | |
672 | struct msdos_dir_slot *slots; | |
673 | unsigned int len; | |
674 | int err, nr_slots; | |
675 | ||
676 | len = vfat_striptail_len(qname); | |
677 | if (len == 0) | |
678 | return -ENOENT; | |
679 | ||
8f593427 | 680 | slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS); |
1da177e4 LT |
681 | if (slots == NULL) |
682 | return -ENOMEM; | |
683 | ||
684 | err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts, | |
685 | slots, &nr_slots); | |
686 | if (err) | |
687 | goto cleanup; | |
688 | ||
689 | err = fat_add_entries(dir, slots, nr_slots, sinfo); | |
690 | if (err) | |
691 | goto cleanup; | |
692 | ||
693 | /* update timestamp */ | |
694 | dir->i_ctime = dir->i_mtime = dir->i_atime = *ts; | |
695 | if (IS_DIRSYNC(dir)) | |
696 | (void)fat_sync_inode(dir); | |
697 | else | |
698 | mark_inode_dirty(dir); | |
699 | cleanup: | |
700 | kfree(slots); | |
701 | return err; | |
702 | } | |
703 | ||
704 | static int vfat_find(struct inode *dir, struct qstr *qname, | |
705 | struct fat_slot_info *sinfo) | |
706 | { | |
707 | unsigned int len = vfat_striptail_len(qname); | |
708 | if (len == 0) | |
709 | return -ENOENT; | |
710 | return fat_search_long(dir, qname->name, len, sinfo); | |
711 | } | |
712 | ||
8045e298 OH |
713 | /* |
714 | * (nfsd's) anonymous disconnected dentry? | |
715 | * NOTE: !IS_ROOT() is not anonymous (I.e. d_splice_alias() did the job). | |
716 | */ | |
717 | static int vfat_d_anon_disconn(struct dentry *dentry) | |
718 | { | |
719 | return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED); | |
720 | } | |
721 | ||
1da177e4 LT |
722 | static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, |
723 | struct nameidata *nd) | |
724 | { | |
725 | struct super_block *sb = dir->i_sb; | |
726 | struct fat_slot_info sinfo; | |
068f5ae0 | 727 | struct inode *inode; |
1da177e4 | 728 | struct dentry *alias; |
1b524672 | 729 | int err; |
1da177e4 | 730 | |
8f593427 | 731 | lock_super(sb); |
1da177e4 LT |
732 | |
733 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
734 | if (err) { | |
068f5ae0 | 735 | if (err == -ENOENT) { |
068f5ae0 OH |
736 | inode = NULL; |
737 | goto out; | |
738 | } | |
1da177e4 LT |
739 | goto error; |
740 | } | |
1b524672 | 741 | |
1da177e4 LT |
742 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); |
743 | brelse(sinfo.bh); | |
744 | if (IS_ERR(inode)) { | |
068f5ae0 OH |
745 | err = PTR_ERR(inode); |
746 | goto error; | |
1da177e4 | 747 | } |
1b524672 | 748 | |
1da177e4 | 749 | alias = d_find_alias(inode); |
8045e298 | 750 | if (alias && !vfat_d_anon_disconn(alias)) { |
1b524672 | 751 | /* |
8045e298 OH |
752 | * This inode has non anonymous-DCACHE_DISCONNECTED |
753 | * dentry. This means, the user did ->lookup() by an | |
754 | * another name (longname vs 8.3 alias of it) in past. | |
1b524672 OH |
755 | * |
756 | * Switch to new one for reason of locality if possible. | |
757 | */ | |
1c13a243 OH |
758 | BUG_ON(d_unhashed(alias)); |
759 | if (!S_ISDIR(inode->i_mode)) | |
760 | d_move(alias, dentry); | |
761 | iput(inode); | |
762 | unlock_super(sb); | |
763 | return alias; | |
8045e298 OH |
764 | } else |
765 | dput(alias); | |
766 | ||
068f5ae0 | 767 | out: |
8f593427 | 768 | unlock_super(sb); |
fb045adb | 769 | d_set_d_op(dentry, sb->s_root->d_op); |
1da177e4 LT |
770 | dentry->d_time = dentry->d_parent->d_inode->i_version; |
771 | dentry = d_splice_alias(inode, dentry); | |
772 | if (dentry) { | |
fb045adb | 773 | d_set_d_op(dentry, sb->s_root->d_op); |
1da177e4 LT |
774 | dentry->d_time = dentry->d_parent->d_inode->i_version; |
775 | } | |
776 | return dentry; | |
068f5ae0 OH |
777 | |
778 | error: | |
779 | unlock_super(sb); | |
780 | return ERR_PTR(err); | |
1da177e4 LT |
781 | } |
782 | ||
783 | static int vfat_create(struct inode *dir, struct dentry *dentry, int mode, | |
784 | struct nameidata *nd) | |
785 | { | |
786 | struct super_block *sb = dir->i_sb; | |
787 | struct inode *inode; | |
788 | struct fat_slot_info sinfo; | |
789 | struct timespec ts; | |
790 | int err; | |
791 | ||
8f593427 | 792 | lock_super(sb); |
1da177e4 LT |
793 | |
794 | ts = CURRENT_TIME_SEC; | |
795 | err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo); | |
796 | if (err) | |
797 | goto out; | |
798 | dir->i_version++; | |
799 | ||
800 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
801 | brelse(sinfo.bh); | |
802 | if (IS_ERR(inode)) { | |
803 | err = PTR_ERR(inode); | |
804 | goto out; | |
805 | } | |
806 | inode->i_version++; | |
807 | inode->i_mtime = inode->i_atime = inode->i_ctime = ts; | |
808 | /* timestamp is already written, so mark_inode_dirty() is unneeded. */ | |
809 | ||
810 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
811 | d_instantiate(dentry, inode); | |
812 | out: | |
8f593427 | 813 | unlock_super(sb); |
1da177e4 LT |
814 | return err; |
815 | } | |
816 | ||
817 | static int vfat_rmdir(struct inode *dir, struct dentry *dentry) | |
818 | { | |
819 | struct inode *inode = dentry->d_inode; | |
8f593427 | 820 | struct super_block *sb = dir->i_sb; |
1da177e4 LT |
821 | struct fat_slot_info sinfo; |
822 | int err; | |
823 | ||
8f593427 | 824 | lock_super(sb); |
1da177e4 LT |
825 | |
826 | err = fat_dir_empty(inode); | |
827 | if (err) | |
828 | goto out; | |
829 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
830 | if (err) | |
831 | goto out; | |
832 | ||
833 | err = fat_remove_entries(dir, &sinfo); /* and releases bh */ | |
834 | if (err) | |
835 | goto out; | |
9a53c3a7 | 836 | drop_nlink(dir); |
1da177e4 | 837 | |
ce71ec36 | 838 | clear_nlink(inode); |
1da177e4 LT |
839 | inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; |
840 | fat_detach(inode); | |
841 | out: | |
8f593427 | 842 | unlock_super(sb); |
1da177e4 LT |
843 | |
844 | return err; | |
845 | } | |
846 | ||
847 | static int vfat_unlink(struct inode *dir, struct dentry *dentry) | |
848 | { | |
849 | struct inode *inode = dentry->d_inode; | |
8f593427 | 850 | struct super_block *sb = dir->i_sb; |
1da177e4 LT |
851 | struct fat_slot_info sinfo; |
852 | int err; | |
853 | ||
8f593427 | 854 | lock_super(sb); |
1da177e4 LT |
855 | |
856 | err = vfat_find(dir, &dentry->d_name, &sinfo); | |
857 | if (err) | |
858 | goto out; | |
859 | ||
860 | err = fat_remove_entries(dir, &sinfo); /* and releases bh */ | |
861 | if (err) | |
862 | goto out; | |
ce71ec36 | 863 | clear_nlink(inode); |
1da177e4 LT |
864 | inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; |
865 | fat_detach(inode); | |
866 | out: | |
8f593427 | 867 | unlock_super(sb); |
1da177e4 LT |
868 | |
869 | return err; | |
870 | } | |
871 | ||
872 | static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
873 | { | |
874 | struct super_block *sb = dir->i_sb; | |
875 | struct inode *inode; | |
876 | struct fat_slot_info sinfo; | |
877 | struct timespec ts; | |
878 | int err, cluster; | |
879 | ||
8f593427 | 880 | lock_super(sb); |
1da177e4 LT |
881 | |
882 | ts = CURRENT_TIME_SEC; | |
883 | cluster = fat_alloc_new_dir(dir, &ts); | |
884 | if (cluster < 0) { | |
885 | err = cluster; | |
886 | goto out; | |
887 | } | |
888 | err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo); | |
889 | if (err) | |
890 | goto out_free; | |
891 | dir->i_version++; | |
d8c76e6f | 892 | inc_nlink(dir); |
1da177e4 LT |
893 | |
894 | inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); | |
895 | brelse(sinfo.bh); | |
896 | if (IS_ERR(inode)) { | |
897 | err = PTR_ERR(inode); | |
898 | /* the directory was completed, just return a error */ | |
899 | goto out; | |
900 | } | |
901 | inode->i_version++; | |
902 | inode->i_nlink = 2; | |
903 | inode->i_mtime = inode->i_atime = inode->i_ctime = ts; | |
904 | /* timestamp is already written, so mark_inode_dirty() is unneeded. */ | |
905 | ||
906 | dentry->d_time = dentry->d_parent->d_inode->i_version; | |
907 | d_instantiate(dentry, inode); | |
908 | ||
8f593427 | 909 | unlock_super(sb); |
1da177e4 LT |
910 | return 0; |
911 | ||
912 | out_free: | |
913 | fat_free_clusters(dir, cluster); | |
914 | out: | |
8f593427 | 915 | unlock_super(sb); |
1da177e4 LT |
916 | return err; |
917 | } | |
918 | ||
919 | static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, | |
920 | struct inode *new_dir, struct dentry *new_dentry) | |
921 | { | |
922 | struct buffer_head *dotdot_bh; | |
923 | struct msdos_dir_entry *dotdot_de; | |
1da177e4 LT |
924 | struct inode *old_inode, *new_inode; |
925 | struct fat_slot_info old_sinfo, sinfo; | |
926 | struct timespec ts; | |
9131dd42 | 927 | loff_t dotdot_i_pos, new_i_pos; |
1da177e4 | 928 | int err, is_dir, update_dotdot, corrupt = 0; |
8f593427 | 929 | struct super_block *sb = old_dir->i_sb; |
1da177e4 LT |
930 | |
931 | old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; | |
932 | old_inode = old_dentry->d_inode; | |
933 | new_inode = new_dentry->d_inode; | |
8f593427 | 934 | lock_super(sb); |
1da177e4 LT |
935 | err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo); |
936 | if (err) | |
937 | goto out; | |
938 | ||
939 | is_dir = S_ISDIR(old_inode->i_mode); | |
940 | update_dotdot = (is_dir && old_dir != new_dir); | |
941 | if (update_dotdot) { | |
942 | if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de, | |
943 | &dotdot_i_pos) < 0) { | |
944 | err = -EIO; | |
945 | goto out; | |
946 | } | |
947 | } | |
948 | ||
949 | ts = CURRENT_TIME_SEC; | |
950 | if (new_inode) { | |
1da177e4 LT |
951 | if (is_dir) { |
952 | err = fat_dir_empty(new_inode); | |
953 | if (err) | |
954 | goto out; | |
955 | } | |
9131dd42 | 956 | new_i_pos = MSDOS_I(new_inode)->i_pos; |
1da177e4 LT |
957 | fat_detach(new_inode); |
958 | } else { | |
959 | err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0, | |
960 | &ts, &sinfo); | |
961 | if (err) | |
962 | goto out; | |
9131dd42 | 963 | new_i_pos = sinfo.i_pos; |
1da177e4 LT |
964 | } |
965 | new_dir->i_version++; | |
966 | ||
967 | fat_detach(old_inode); | |
9131dd42 | 968 | fat_attach(old_inode, new_i_pos); |
1da177e4 LT |
969 | if (IS_DIRSYNC(new_dir)) { |
970 | err = fat_sync_inode(old_inode); | |
971 | if (err) | |
972 | goto error_inode; | |
973 | } else | |
974 | mark_inode_dirty(old_inode); | |
975 | ||
976 | if (update_dotdot) { | |
977 | int start = MSDOS_I(new_dir)->i_logstart; | |
978 | dotdot_de->start = cpu_to_le16(start); | |
979 | dotdot_de->starthi = cpu_to_le16(start >> 16); | |
b522412a | 980 | mark_buffer_dirty_inode(dotdot_bh, old_inode); |
1da177e4 LT |
981 | if (IS_DIRSYNC(new_dir)) { |
982 | err = sync_dirty_buffer(dotdot_bh); | |
983 | if (err) | |
984 | goto error_dotdot; | |
985 | } | |
9a53c3a7 | 986 | drop_nlink(old_dir); |
1da177e4 | 987 | if (!new_inode) |
d8c76e6f | 988 | inc_nlink(new_dir); |
1da177e4 LT |
989 | } |
990 | ||
991 | err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ | |
992 | old_sinfo.bh = NULL; | |
993 | if (err) | |
994 | goto error_dotdot; | |
995 | old_dir->i_version++; | |
996 | old_dir->i_ctime = old_dir->i_mtime = ts; | |
997 | if (IS_DIRSYNC(old_dir)) | |
998 | (void)fat_sync_inode(old_dir); | |
999 | else | |
1000 | mark_inode_dirty(old_dir); | |
1001 | ||
1002 | if (new_inode) { | |
9a53c3a7 | 1003 | drop_nlink(new_inode); |
1da177e4 | 1004 | if (is_dir) |
9a53c3a7 | 1005 | drop_nlink(new_inode); |
1da177e4 LT |
1006 | new_inode->i_ctime = ts; |
1007 | } | |
1008 | out: | |
1009 | brelse(sinfo.bh); | |
1010 | brelse(dotdot_bh); | |
1011 | brelse(old_sinfo.bh); | |
8f593427 | 1012 | unlock_super(sb); |
1da177e4 LT |
1013 | |
1014 | return err; | |
1015 | ||
1016 | error_dotdot: | |
1017 | /* data cluster is shared, serious corruption */ | |
1018 | corrupt = 1; | |
1019 | ||
1020 | if (update_dotdot) { | |
1021 | int start = MSDOS_I(old_dir)->i_logstart; | |
1022 | dotdot_de->start = cpu_to_le16(start); | |
1023 | dotdot_de->starthi = cpu_to_le16(start >> 16); | |
b522412a | 1024 | mark_buffer_dirty_inode(dotdot_bh, old_inode); |
1da177e4 LT |
1025 | corrupt |= sync_dirty_buffer(dotdot_bh); |
1026 | } | |
1027 | error_inode: | |
1028 | fat_detach(old_inode); | |
1029 | fat_attach(old_inode, old_sinfo.i_pos); | |
1030 | if (new_inode) { | |
9131dd42 | 1031 | fat_attach(new_inode, new_i_pos); |
1da177e4 LT |
1032 | if (corrupt) |
1033 | corrupt |= fat_sync_inode(new_inode); | |
1034 | } else { | |
1035 | /* | |
1036 | * If new entry was not sharing the data cluster, it | |
1037 | * shouldn't be serious corruption. | |
1038 | */ | |
1039 | int err2 = fat_remove_entries(new_dir, &sinfo); | |
1040 | if (corrupt) | |
1041 | corrupt |= err2; | |
1042 | sinfo.bh = NULL; | |
1043 | } | |
1044 | if (corrupt < 0) { | |
85c78591 | 1045 | fat_fs_error(new_dir->i_sb, |
1da177e4 | 1046 | "%s: Filesystem corrupted (i_pos %lld)", |
8e24eea7 | 1047 | __func__, sinfo.i_pos); |
1da177e4 LT |
1048 | } |
1049 | goto out; | |
1050 | } | |
1051 | ||
c5ef1c42 | 1052 | static const struct inode_operations vfat_dir_inode_operations = { |
1da177e4 LT |
1053 | .create = vfat_create, |
1054 | .lookup = vfat_lookup, | |
1055 | .unlink = vfat_unlink, | |
1056 | .mkdir = vfat_mkdir, | |
1057 | .rmdir = vfat_rmdir, | |
1058 | .rename = vfat_rename, | |
1278fdd3 | 1059 | .setattr = fat_setattr, |
da63fc7c | 1060 | .getattr = fat_getattr, |
1da177e4 LT |
1061 | }; |
1062 | ||
1063 | static int vfat_fill_super(struct super_block *sb, void *data, int silent) | |
1064 | { | |
1065 | int res; | |
1066 | ||
3768744c | 1067 | lock_super(sb); |
1da177e4 | 1068 | res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1); |
db719222 | 1069 | if (res) { |
3768744c | 1070 | unlock_super(sb); |
1da177e4 | 1071 | return res; |
db719222 | 1072 | } |
1da177e4 LT |
1073 | |
1074 | if (MSDOS_SB(sb)->options.name_check != 's') | |
fb045adb | 1075 | d_set_d_op(sb->s_root, &vfat_ci_dentry_ops); |
1da177e4 | 1076 | else |
fb045adb | 1077 | d_set_d_op(sb->s_root, &vfat_dentry_ops); |
1da177e4 | 1078 | |
3768744c | 1079 | unlock_super(sb); |
1da177e4 LT |
1080 | return 0; |
1081 | } | |
1082 | ||
152a0836 | 1083 | static struct dentry *vfat_mount(struct file_system_type *fs_type, |
454e2398 | 1084 | int flags, const char *dev_name, |
152a0836 | 1085 | void *data) |
1da177e4 | 1086 | { |
152a0836 | 1087 | return mount_bdev(fs_type, flags, dev_name, data, vfat_fill_super); |
1da177e4 LT |
1088 | } |
1089 | ||
1090 | static struct file_system_type vfat_fs_type = { | |
1091 | .owner = THIS_MODULE, | |
1092 | .name = "vfat", | |
152a0836 | 1093 | .mount = vfat_mount, |
1da177e4 LT |
1094 | .kill_sb = kill_block_super, |
1095 | .fs_flags = FS_REQUIRES_DEV, | |
1096 | }; | |
1097 | ||
1098 | static int __init init_vfat_fs(void) | |
1099 | { | |
1100 | return register_filesystem(&vfat_fs_type); | |
1101 | } | |
1102 | ||
1103 | static void __exit exit_vfat_fs(void) | |
1104 | { | |
1105 | unregister_filesystem(&vfat_fs_type); | |
1106 | } | |
1107 | ||
1108 | MODULE_LICENSE("GPL"); | |
1109 | MODULE_DESCRIPTION("VFAT filesystem support"); | |
1110 | MODULE_AUTHOR("Gordon Chaffee"); | |
1111 | ||
1112 | module_init(init_vfat_fs) | |
1113 | module_exit(exit_vfat_fs) |