blob: b936703b8924491a2671b8432c67570d18e9a810 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/jiffies.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/ctype.h>
21#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/buffer_head.h>
23#include <linux/namei.h>
OGAWA Hirofumi9e975da2008-11-06 12:53:46 -080024#include "fat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
OGAWA Hirofumi1b524672008-11-06 12:53:51 -080026/*
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 */
34static int vfat_revalidate_shortname(struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
36 int ret = 1;
OGAWA Hirofumi1b524672008-11-06 12:53:51 -080037 spin_lock(&dentry->d_lock);
38 if (dentry->d_time != dentry->d_parent->d_inode->i_version)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 ret = 0;
OGAWA Hirofumi1b524672008-11-06 12:53:51 -080040 spin_unlock(&dentry->d_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 return ret;
42}
43
OGAWA Hirofumi1b524672008-11-06 12:53:51 -080044static 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
52static 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))) {
OGAWA Hirofumiebeb0402008-11-12 07:48:00 +090080 if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
OGAWA Hirofumi1b524672008-11-06 12:53:51 -080081 return 0;
82 }
83
84 return vfat_revalidate_shortname(dentry);
85}
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087/* returns the length of a struct qstr, ignoring trailing dots */
88static unsigned int vfat_striptail_len(struct qstr *qstr)
89{
90 unsigned int len = qstr->len;
91
92 while (len && qstr->name[len - 1] == '.')
93 len--;
94 return len;
95}
96
97/*
98 * Compute the hash for the vfat name corresponding to the dentry.
99 * Note: if the name is invalid, we leave the hash code unchanged so
100 * that the existing dentry can be used. The vfat fs routines will
101 * return ENOENT or EINVAL as appropriate.
102 */
103static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
104{
105 qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
106 return 0;
107}
108
109/*
110 * Compute the hash for the vfat name corresponding to the dentry.
111 * Note: if the name is invalid, we leave the hash code unchanged so
112 * that the existing dentry can be used. The vfat fs routines will
113 * return ENOENT or EINVAL as appropriate.
114 */
115static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
116{
117 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
118 const unsigned char *name;
119 unsigned int len;
120 unsigned long hash;
121
122 name = qstr->name;
123 len = vfat_striptail_len(qstr);
124
125 hash = init_name_hash();
126 while (len--)
127 hash = partial_name_hash(nls_tolower(t, *name++), hash);
128 qstr->hash = end_name_hash(hash);
129
130 return 0;
131}
132
133/*
134 * Case insensitive compare of two vfat names.
135 */
136static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
137{
138 struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
139 unsigned int alen, blen;
140
141 /* A filename cannot end in '.' or we treat it like it has none */
142 alen = vfat_striptail_len(a);
143 blen = vfat_striptail_len(b);
144 if (alen == blen) {
145 if (nls_strnicmp(t, a->name, b->name, alen) == 0)
146 return 0;
147 }
148 return 1;
149}
150
151/*
152 * Case sensitive compare of two vfat names.
153 */
154static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
155{
156 unsigned int alen, blen;
157
158 /* A filename cannot end in '.' or we treat it like it has none */
159 alen = vfat_striptail_len(a);
160 blen = vfat_striptail_len(b);
161 if (alen == blen) {
162 if (strncmp(a->name, b->name, alen) == 0)
163 return 0;
164 }
165 return 1;
166}
167
Al Viroce6cdc42009-02-20 05:59:46 +0000168static const struct dentry_operations vfat_ci_dentry_ops = {
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800169 .d_revalidate = vfat_revalidate_ci,
170 .d_hash = vfat_hashi,
171 .d_compare = vfat_cmpi,
172};
173
Al Viroce6cdc42009-02-20 05:59:46 +0000174static const struct dentry_operations vfat_dentry_ops = {
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800175 .d_revalidate = vfat_revalidate,
176 .d_hash = vfat_hash,
177 .d_compare = vfat_cmp,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178};
179
180/* Characters that are undesirable in an MS-DOS file name */
181
182static inline wchar_t vfat_bad_char(wchar_t w)
183{
184 return (w < 0x0020)
185 || (w == '*') || (w == '?') || (w == '<') || (w == '>')
186 || (w == '|') || (w == '"') || (w == ':') || (w == '/')
187 || (w == '\\');
188}
189
190static inline wchar_t vfat_replace_char(wchar_t w)
191{
192 return (w == '[') || (w == ']') || (w == ';') || (w == ',')
193 || (w == '+') || (w == '=');
194}
195
196static wchar_t vfat_skip_char(wchar_t w)
197{
198 return (w == '.') || (w == ' ');
199}
200
201static inline int vfat_is_used_badchars(const wchar_t *s, int len)
202{
203 int i;
204
205 for (i = 0; i < len; i++)
206 if (vfat_bad_char(s[i]))
207 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Keith Mokf22032b2008-04-28 02:16:29 -0700209 if (s[i - 1] == ' ') /* last character cannot be space */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 return -EINVAL;
Keith Mokf22032b2008-04-28 02:16:29 -0700211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 return 0;
213}
214
215static int vfat_find_form(struct inode *dir, unsigned char *name)
216{
217 struct fat_slot_info sinfo;
218 int err = fat_scan(dir, name, &sinfo);
219 if (err)
220 return -ENOENT;
221 brelse(sinfo.bh);
222 return 0;
223}
224
225/*
226 * 1) Valid characters for the 8.3 format alias are any combination of
227 * letters, uppercase alphabets, digits, any of the
228 * following special characters:
229 * $ % ' ` - @ { } ~ ! # ( ) & _ ^
230 * In this case Longfilename is not stored in disk.
231 *
232 * WinNT's Extension:
233 * File name and extension name is contain uppercase/lowercase
234 * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
235 *
236 * 2) File name is 8.3 format, but it contain the uppercase and
237 * lowercase char, muliti bytes char, etc. In this case numtail is not
238 * added, but Longfilename is stored.
239 *
240 * 3) When the one except for the above, or the following special
241 * character are contained:
242 * . [ ] ; , + =
243 * numtail is added, and Longfilename must be stored in disk .
244 */
245struct shortname_info {
246 unsigned char lower:1,
247 upper:1,
248 valid:1;
249};
250#define INIT_SHORTNAME_INFO(x) do { \
251 (x)->lower = 1; \
252 (x)->upper = 1; \
253 (x)->valid = 1; \
254} while (0)
255
256static inline int to_shortname_char(struct nls_table *nls,
257 unsigned char *buf, int buf_size,
258 wchar_t *src, struct shortname_info *info)
259{
260 int len;
261
262 if (vfat_skip_char(*src)) {
263 info->valid = 0;
264 return 0;
265 }
266 if (vfat_replace_char(*src)) {
267 info->valid = 0;
268 buf[0] = '_';
269 return 1;
270 }
271
272 len = nls->uni2char(*src, buf, buf_size);
273 if (len <= 0) {
274 info->valid = 0;
275 buf[0] = '_';
276 len = 1;
277 } else if (len == 1) {
278 unsigned char prev = buf[0];
279
280 if (buf[0] >= 0x7F) {
281 info->lower = 0;
282 info->upper = 0;
283 }
284
285 buf[0] = nls_toupper(nls, buf[0]);
286 if (isalpha(buf[0])) {
287 if (buf[0] == prev)
288 info->lower = 0;
289 else
290 info->upper = 0;
291 }
292 } else {
293 info->lower = 0;
294 info->upper = 0;
295 }
296
297 return len;
298}
299
300/*
301 * Given a valid longname, create a unique shortname. Make sure the
302 * shortname does not exist
303 * Returns negative number on error, 0 for a normal
304 * return, and 1 for valid shortname
305 */
306static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
307 wchar_t *uname, int ulen,
308 unsigned char *name_res, unsigned char *lcase)
309{
310 struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
311 wchar_t *ip, *ext_start, *end, *name_start;
Nikolaus Schulz30d18722010-04-01 02:21:10 +0900312 unsigned char base[9], ext[4], buf[5], *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
314 int chl, chi;
315 int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
316 int is_shortname;
317 struct shortname_info base_info, ext_info;
318
319 is_shortname = 1;
320 INIT_SHORTNAME_INFO(&base_info);
321 INIT_SHORTNAME_INFO(&ext_info);
322
323 /* Now, we need to create a shortname from the long name */
324 ext_start = end = &uname[ulen];
325 while (--ext_start >= uname) {
326 if (*ext_start == 0x002E) { /* is `.' */
327 if (ext_start == end - 1) {
328 sz = ulen;
329 ext_start = NULL;
330 }
331 break;
332 }
333 }
334
335 if (ext_start == uname - 1) {
336 sz = ulen;
337 ext_start = NULL;
338 } else if (ext_start) {
339 /*
340 * Names which start with a dot could be just
341 * an extension eg. "...test". In this case Win95
342 * uses the extension as the name and sets no extension.
343 */
344 name_start = &uname[0];
345 while (name_start < ext_start) {
346 if (!vfat_skip_char(*name_start))
347 break;
348 name_start++;
349 }
350 if (name_start != ext_start) {
351 sz = ext_start - uname;
352 ext_start++;
353 } else {
354 sz = ulen;
355 ext_start = NULL;
356 }
357 }
358
359 numtail_baselen = 6;
360 numtail2_baselen = 2;
361 for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
362 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
363 ip, &base_info);
364 if (chl == 0)
365 continue;
366
367 if (baselen < 2 && (baselen + chl) > 2)
368 numtail2_baselen = baselen;
369 if (baselen < 6 && (baselen + chl) > 6)
370 numtail_baselen = baselen;
371 for (chi = 0; chi < chl; chi++) {
372 *p++ = charbuf[chi];
373 baselen++;
374 if (baselen >= 8)
375 break;
376 }
377 if (baselen >= 8) {
378 if ((chi < chl - 1) || (ip + 1) - uname < sz)
379 is_shortname = 0;
380 break;
381 }
382 }
383 if (baselen == 0) {
384 return -EINVAL;
385 }
386
387 extlen = 0;
388 if (ext_start) {
389 for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
390 chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
391 ip, &ext_info);
392 if (chl == 0)
393 continue;
394
395 if ((extlen + chl) > 3) {
396 is_shortname = 0;
397 break;
398 }
399 for (chi = 0; chi < chl; chi++) {
400 *p++ = charbuf[chi];
401 extlen++;
402 }
403 if (extlen >= 3) {
404 if (ip + 1 != end)
405 is_shortname = 0;
406 break;
407 }
408 }
409 }
410 ext[extlen] = '\0';
411 base[baselen] = '\0';
412
413 /* Yes, it can happen. ".\xe5" would do it. */
414 if (base[0] == DELETED_FLAG)
415 base[0] = 0x05;
416
417 /* OK, at this point we know that base is not longer than 8 symbols,
418 * ext is not longer than 3, base is nonempty, both don't contain
419 * any bad symbols (lowercase transformed to uppercase).
420 */
421
422 memset(name_res, ' ', MSDOS_NAME);
423 memcpy(name_res, base, baselen);
424 memcpy(name_res + 8, ext, extlen);
425 *lcase = 0;
426 if (is_shortname && base_info.valid && ext_info.valid) {
427 if (vfat_find_form(dir, name_res) == 0)
428 return -EEXIST;
429
430 if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
431 return (base_info.upper && ext_info.upper);
432 } else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
433 if ((base_info.upper || base_info.lower) &&
434 (ext_info.upper || ext_info.lower)) {
435 if (!base_info.upper && base_info.lower)
436 *lcase |= CASE_LOWER_BASE;
437 if (!ext_info.upper && ext_info.lower)
438 *lcase |= CASE_LOWER_EXT;
439 return 1;
440 }
441 return 0;
442 } else {
443 BUG();
444 }
445 }
446
447 if (opts->numtail == 0)
448 if (vfat_find_form(dir, name_res) < 0)
449 return 0;
450
451 /*
452 * Try to find a unique extension. This used to
453 * iterate through all possibilities sequentially,
454 * but that gave extremely bad performance. Windows
455 * only tries a few cases before using random
456 * values for part of the base.
457 */
458
459 if (baselen > 6) {
460 baselen = numtail_baselen;
461 name_res[7] = ' ';
462 }
463 name_res[baselen] = '~';
464 for (i = 1; i < 10; i++) {
465 name_res[baselen + 1] = i + '0';
466 if (vfat_find_form(dir, name_res) < 0)
467 return 0;
468 }
469
Nikolaus Schulz30d18722010-04-01 02:21:10 +0900470 i = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 sz = (jiffies >> 16) & 0x7;
472 if (baselen > 2) {
473 baselen = numtail2_baselen;
474 name_res[7] = ' ';
475 }
476 name_res[baselen + 4] = '~';
477 name_res[baselen + 5] = '1' + sz;
478 while (1) {
Nikolaus Schulz30d18722010-04-01 02:21:10 +0900479 snprintf(buf, sizeof(buf), "%04X", i & 0xffff);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 memcpy(&name_res[baselen], buf, 4);
481 if (vfat_find_form(dir, name_res) < 0)
482 break;
483 i -= 11;
484 }
485 return 0;
486}
487
488/* Translate a string, including coded sequences into Unicode */
489static int
490xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
491 int *longlen, int *outlen, int escape, int utf8,
492 struct nls_table *nls)
493{
494 const unsigned char *ip;
495 unsigned char nc;
496 unsigned char *op;
497 unsigned int ec;
498 int i, k, fill;
499 int charlen;
500
501 if (utf8) {
OGAWA Hirofumi67638e42009-08-01 21:30:31 +0900502 *outlen = utf8s_to_utf16s(name, len, (wchar_t *)outname);
503 if (*outlen < 0)
504 return *outlen;
Kevin Dankwardteeb5b4a2010-02-10 23:43:40 +0900505 else if (*outlen > FAT_LFN_LEN)
Keith Mokf22032b2008-04-28 02:16:29 -0700506 return -ENAMETOOLONG;
507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 op = &outname[*outlen * sizeof(wchar_t)];
509 } else {
510 if (nls) {
511 for (i = 0, ip = name, op = outname, *outlen = 0;
Kevin Dankwardteeb5b4a2010-02-10 23:43:40 +0900512 i < len && *outlen <= FAT_LFN_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 *outlen += 1)
514 {
515 if (escape && (*ip == ':')) {
516 if (i > len - 5)
517 return -EINVAL;
518 ec = 0;
519 for (k = 1; k < 5; k++) {
520 nc = ip[k];
521 ec <<= 4;
522 if (nc >= '0' && nc <= '9') {
523 ec |= nc - '0';
524 continue;
525 }
526 if (nc >= 'a' && nc <= 'f') {
527 ec |= nc - ('a' - 10);
528 continue;
529 }
530 if (nc >= 'A' && nc <= 'F') {
531 ec |= nc - ('A' - 10);
532 continue;
533 }
534 return -EINVAL;
535 }
536 *op++ = ec & 0xFF;
537 *op++ = ec >> 8;
538 ip += 5;
539 i += 5;
540 } else {
541 if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
542 return -EINVAL;
543 ip += charlen;
544 i += charlen;
545 op += 2;
546 }
547 }
Keith Mokf22032b2008-04-28 02:16:29 -0700548 if (i < len)
549 return -ENAMETOOLONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 } else {
551 for (i = 0, ip = name, op = outname, *outlen = 0;
Kevin Dankwardteeb5b4a2010-02-10 23:43:40 +0900552 i < len && *outlen <= FAT_LFN_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 i++, *outlen += 1)
554 {
555 *op++ = *ip++;
556 *op++ = 0;
557 }
Keith Mokf22032b2008-04-28 02:16:29 -0700558 if (i < len)
559 return -ENAMETOOLONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 }
561 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
563 *longlen = *outlen;
564 if (*outlen % 13) {
565 *op++ = 0;
566 *op++ = 0;
567 *outlen += 1;
568 if (*outlen % 13) {
569 fill = 13 - (*outlen % 13);
570 for (i = 0; i < fill; i++) {
571 *op++ = 0xff;
572 *op++ = 0xff;
573 }
574 *outlen += fill;
575 }
576 }
577
578 return 0;
579}
580
581static int vfat_build_slots(struct inode *dir, const unsigned char *name,
582 int len, int is_dir, int cluster,
583 struct timespec *ts,
584 struct msdos_dir_slot *slots, int *nr_slots)
585{
586 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
587 struct fat_mount_options *opts = &sbi->options;
588 struct msdos_dir_slot *ps;
589 struct msdos_dir_entry *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 unsigned char cksum, lcase;
591 unsigned char msdos_name[MSDOS_NAME];
592 wchar_t *uname;
593 __le16 time, date;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800594 u8 time_cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 int err, ulen, usize, i;
596 loff_t offset;
597
598 *nr_slots = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700600 uname = __getname();
601 if (!uname)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 return -ENOMEM;
603
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
605 opts->unicode_xlate, opts->utf8, sbi->nls_io);
606 if (err)
607 goto out_free;
608
609 err = vfat_is_used_badchars(uname, ulen);
610 if (err)
611 goto out_free;
612
613 err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
614 msdos_name, &lcase);
615 if (err < 0)
616 goto out_free;
617 else if (err == 1) {
618 de = (struct msdos_dir_entry *)slots;
619 err = 0;
620 goto shortname;
621 }
622
623 /* build the entry of long file name */
OGAWA Hirofumi451cbaa2005-10-30 15:03:49 -0800624 cksum = fat_checksum(msdos_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626 *nr_slots = usize / 13;
627 for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
628 ps->id = i;
629 ps->attr = ATTR_EXT;
630 ps->reserved = 0;
631 ps->alias_checksum = cksum;
632 ps->start = 0;
633 offset = (i - 1) * 13;
634 fatwchar_to16(ps->name0_4, uname + offset, 5);
635 fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
636 fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
637 }
638 slots[0].id |= 0x40;
639 de = (struct msdos_dir_entry *)ps;
640
641shortname:
642 /* build the entry of 8.3 alias name */
643 (*nr_slots)++;
644 memcpy(de->name, msdos_name, MSDOS_NAME);
645 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
646 de->lcase = lcase;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800647 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 de->time = de->ctime = time;
649 de->date = de->cdate = de->adate = date;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800650 de->ctime_cs = time_cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 de->start = cpu_to_le16(cluster);
652 de->starthi = cpu_to_le16(cluster >> 16);
653 de->size = 0;
654out_free:
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700655 __putname(uname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 return err;
657}
658
659static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
660 int cluster, struct timespec *ts,
661 struct fat_slot_info *sinfo)
662{
663 struct msdos_dir_slot *slots;
664 unsigned int len;
665 int err, nr_slots;
666
667 len = vfat_striptail_len(qname);
668 if (len == 0)
669 return -ENOENT;
670
Linus Torvalds8f593422008-05-19 19:53:01 -0700671 slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 if (slots == NULL)
673 return -ENOMEM;
674
675 err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
676 slots, &nr_slots);
677 if (err)
678 goto cleanup;
679
680 err = fat_add_entries(dir, slots, nr_slots, sinfo);
681 if (err)
682 goto cleanup;
683
684 /* update timestamp */
685 dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
686 if (IS_DIRSYNC(dir))
687 (void)fat_sync_inode(dir);
688 else
689 mark_inode_dirty(dir);
690cleanup:
691 kfree(slots);
692 return err;
693}
694
695static int vfat_find(struct inode *dir, struct qstr *qname,
696 struct fat_slot_info *sinfo)
697{
698 unsigned int len = vfat_striptail_len(qname);
699 if (len == 0)
700 return -ENOENT;
701 return fat_search_long(dir, qname->name, len, sinfo);
702}
703
OGAWA Hirofumi8045e292010-01-12 03:32:24 +0900704/*
705 * (nfsd's) anonymous disconnected dentry?
706 * NOTE: !IS_ROOT() is not anonymous (I.e. d_splice_alias() did the job).
707 */
708static int vfat_d_anon_disconn(struct dentry *dentry)
709{
710 return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
711}
712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
714 struct nameidata *nd)
715{
716 struct super_block *sb = dir->i_sb;
717 struct fat_slot_info sinfo;
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800718 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 struct dentry *alias;
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800720 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
Linus Torvalds8f593422008-05-19 19:53:01 -0700722 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723
724 err = vfat_find(dir, &dentry->d_name, &sinfo);
725 if (err) {
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800726 if (err == -ENOENT) {
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800727 inode = NULL;
728 goto out;
729 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 goto error;
731 }
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800732
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
734 brelse(sinfo.bh);
735 if (IS_ERR(inode)) {
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800736 err = PTR_ERR(inode);
737 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 }
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 alias = d_find_alias(inode);
OGAWA Hirofumi8045e292010-01-12 03:32:24 +0900741 if (alias && !vfat_d_anon_disconn(alias)) {
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800742 /*
OGAWA Hirofumi8045e292010-01-12 03:32:24 +0900743 * This inode has non anonymous-DCACHE_DISCONNECTED
744 * dentry. This means, the user did ->lookup() by an
745 * another name (longname vs 8.3 alias of it) in past.
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800746 *
747 * Switch to new one for reason of locality if possible.
748 */
OGAWA Hirofumi1c13a242008-11-06 12:53:52 -0800749 BUG_ON(d_unhashed(alias));
750 if (!S_ISDIR(inode->i_mode))
751 d_move(alias, dentry);
752 iput(inode);
753 unlock_super(sb);
754 return alias;
OGAWA Hirofumi8045e292010-01-12 03:32:24 +0900755 } else
756 dput(alias);
757
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800758out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700759 unlock_super(sb);
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800760 dentry->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 dentry->d_time = dentry->d_parent->d_inode->i_version;
762 dentry = d_splice_alias(inode, dentry);
763 if (dentry) {
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800764 dentry->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 dentry->d_time = dentry->d_parent->d_inode->i_version;
766 }
767 return dentry;
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800768
769error:
770 unlock_super(sb);
771 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772}
773
774static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
775 struct nameidata *nd)
776{
777 struct super_block *sb = dir->i_sb;
778 struct inode *inode;
779 struct fat_slot_info sinfo;
780 struct timespec ts;
781 int err;
782
Linus Torvalds8f593422008-05-19 19:53:01 -0700783 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784
785 ts = CURRENT_TIME_SEC;
786 err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
787 if (err)
788 goto out;
789 dir->i_version++;
790
791 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
792 brelse(sinfo.bh);
793 if (IS_ERR(inode)) {
794 err = PTR_ERR(inode);
795 goto out;
796 }
797 inode->i_version++;
798 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
799 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
800
801 dentry->d_time = dentry->d_parent->d_inode->i_version;
802 d_instantiate(dentry, inode);
803out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700804 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 return err;
806}
807
808static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
809{
810 struct inode *inode = dentry->d_inode;
Linus Torvalds8f593422008-05-19 19:53:01 -0700811 struct super_block *sb = dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 struct fat_slot_info sinfo;
813 int err;
814
Linus Torvalds8f593422008-05-19 19:53:01 -0700815 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816
817 err = fat_dir_empty(inode);
818 if (err)
819 goto out;
820 err = vfat_find(dir, &dentry->d_name, &sinfo);
821 if (err)
822 goto out;
823
824 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
825 if (err)
826 goto out;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700827 drop_nlink(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828
Dave Hansence71ec32006-09-30 23:29:06 -0700829 clear_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
831 fat_detach(inode);
832out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700833 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
835 return err;
836}
837
838static int vfat_unlink(struct inode *dir, struct dentry *dentry)
839{
840 struct inode *inode = dentry->d_inode;
Linus Torvalds8f593422008-05-19 19:53:01 -0700841 struct super_block *sb = dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 struct fat_slot_info sinfo;
843 int err;
844
Linus Torvalds8f593422008-05-19 19:53:01 -0700845 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
847 err = vfat_find(dir, &dentry->d_name, &sinfo);
848 if (err)
849 goto out;
850
851 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
852 if (err)
853 goto out;
Dave Hansence71ec32006-09-30 23:29:06 -0700854 clear_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
856 fat_detach(inode);
857out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700858 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
860 return err;
861}
862
863static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
864{
865 struct super_block *sb = dir->i_sb;
866 struct inode *inode;
867 struct fat_slot_info sinfo;
868 struct timespec ts;
869 int err, cluster;
870
Linus Torvalds8f593422008-05-19 19:53:01 -0700871 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872
873 ts = CURRENT_TIME_SEC;
874 cluster = fat_alloc_new_dir(dir, &ts);
875 if (cluster < 0) {
876 err = cluster;
877 goto out;
878 }
879 err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
880 if (err)
881 goto out_free;
882 dir->i_version++;
Dave Hansend8c76e62006-09-30 23:29:04 -0700883 inc_nlink(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
885 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
886 brelse(sinfo.bh);
887 if (IS_ERR(inode)) {
888 err = PTR_ERR(inode);
889 /* the directory was completed, just return a error */
890 goto out;
891 }
892 inode->i_version++;
893 inode->i_nlink = 2;
894 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
895 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
896
897 dentry->d_time = dentry->d_parent->d_inode->i_version;
898 d_instantiate(dentry, inode);
899
Linus Torvalds8f593422008-05-19 19:53:01 -0700900 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 return 0;
902
903out_free:
904 fat_free_clusters(dir, cluster);
905out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700906 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 return err;
908}
909
910static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
911 struct inode *new_dir, struct dentry *new_dentry)
912{
913 struct buffer_head *dotdot_bh;
914 struct msdos_dir_entry *dotdot_de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 struct inode *old_inode, *new_inode;
916 struct fat_slot_info old_sinfo, sinfo;
917 struct timespec ts;
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800918 loff_t dotdot_i_pos, new_i_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 int err, is_dir, update_dotdot, corrupt = 0;
Linus Torvalds8f593422008-05-19 19:53:01 -0700920 struct super_block *sb = old_dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921
922 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
923 old_inode = old_dentry->d_inode;
924 new_inode = new_dentry->d_inode;
Linus Torvalds8f593422008-05-19 19:53:01 -0700925 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
927 if (err)
928 goto out;
929
930 is_dir = S_ISDIR(old_inode->i_mode);
931 update_dotdot = (is_dir && old_dir != new_dir);
932 if (update_dotdot) {
933 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
934 &dotdot_i_pos) < 0) {
935 err = -EIO;
936 goto out;
937 }
938 }
939
940 ts = CURRENT_TIME_SEC;
941 if (new_inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942 if (is_dir) {
943 err = fat_dir_empty(new_inode);
944 if (err)
945 goto out;
946 }
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800947 new_i_pos = MSDOS_I(new_inode)->i_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 fat_detach(new_inode);
949 } else {
950 err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
951 &ts, &sinfo);
952 if (err)
953 goto out;
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800954 new_i_pos = sinfo.i_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 }
956 new_dir->i_version++;
957
958 fat_detach(old_inode);
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800959 fat_attach(old_inode, new_i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 if (IS_DIRSYNC(new_dir)) {
961 err = fat_sync_inode(old_inode);
962 if (err)
963 goto error_inode;
964 } else
965 mark_inode_dirty(old_inode);
966
967 if (update_dotdot) {
968 int start = MSDOS_I(new_dir)->i_logstart;
969 dotdot_de->start = cpu_to_le16(start);
970 dotdot_de->starthi = cpu_to_le16(start >> 16);
Al Virob5224122009-06-07 13:44:36 -0400971 mark_buffer_dirty_inode(dotdot_bh, old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 if (IS_DIRSYNC(new_dir)) {
973 err = sync_dirty_buffer(dotdot_bh);
974 if (err)
975 goto error_dotdot;
976 }
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700977 drop_nlink(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 if (!new_inode)
Dave Hansend8c76e62006-09-30 23:29:04 -0700979 inc_nlink(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 }
981
982 err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
983 old_sinfo.bh = NULL;
984 if (err)
985 goto error_dotdot;
986 old_dir->i_version++;
987 old_dir->i_ctime = old_dir->i_mtime = ts;
988 if (IS_DIRSYNC(old_dir))
989 (void)fat_sync_inode(old_dir);
990 else
991 mark_inode_dirty(old_dir);
992
993 if (new_inode) {
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700994 drop_nlink(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 if (is_dir)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700996 drop_nlink(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 new_inode->i_ctime = ts;
998 }
999out:
1000 brelse(sinfo.bh);
1001 brelse(dotdot_bh);
1002 brelse(old_sinfo.bh);
Linus Torvalds8f593422008-05-19 19:53:01 -07001003 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004
1005 return err;
1006
1007error_dotdot:
1008 /* data cluster is shared, serious corruption */
1009 corrupt = 1;
1010
1011 if (update_dotdot) {
1012 int start = MSDOS_I(old_dir)->i_logstart;
1013 dotdot_de->start = cpu_to_le16(start);
1014 dotdot_de->starthi = cpu_to_le16(start >> 16);
Al Virob5224122009-06-07 13:44:36 -04001015 mark_buffer_dirty_inode(dotdot_bh, old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 corrupt |= sync_dirty_buffer(dotdot_bh);
1017 }
1018error_inode:
1019 fat_detach(old_inode);
1020 fat_attach(old_inode, old_sinfo.i_pos);
1021 if (new_inode) {
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -08001022 fat_attach(new_inode, new_i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 if (corrupt)
1024 corrupt |= fat_sync_inode(new_inode);
1025 } else {
1026 /*
1027 * If new entry was not sharing the data cluster, it
1028 * shouldn't be serious corruption.
1029 */
1030 int err2 = fat_remove_entries(new_dir, &sinfo);
1031 if (corrupt)
1032 corrupt |= err2;
1033 sinfo.bh = NULL;
1034 }
1035 if (corrupt < 0) {
Denis Karpov85c78592009-06-04 02:34:22 +09001036 fat_fs_error(new_dir->i_sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 "%s: Filesystem corrupted (i_pos %lld)",
Harvey Harrison8e24eea2008-04-30 00:55:09 -07001038 __func__, sinfo.i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 }
1040 goto out;
1041}
1042
Arjan van de Venc5ef1c42007-02-12 00:55:40 -08001043static const struct inode_operations vfat_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 .create = vfat_create,
1045 .lookup = vfat_lookup,
1046 .unlink = vfat_unlink,
1047 .mkdir = vfat_mkdir,
1048 .rmdir = vfat_rmdir,
1049 .rename = vfat_rename,
OGAWA Hirofumi1278fdd2008-04-28 02:16:25 -07001050 .setattr = fat_setattr,
OGAWA Hirofumida63fc72006-11-16 01:19:28 -08001051 .getattr = fat_getattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052};
1053
1054static int vfat_fill_super(struct super_block *sb, void *data, int silent)
1055{
1056 int res;
1057
Arnd Bergmann37687442010-09-14 23:07:27 +02001058 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
Jan Blunckdb719222010-08-15 22:51:10 +02001060 if (res) {
Arnd Bergmann37687442010-09-14 23:07:27 +02001061 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 return res;
Jan Blunckdb719222010-08-15 22:51:10 +02001063 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064
1065 if (MSDOS_SB(sb)->options.name_check != 's')
OGAWA Hirofumi1b524672008-11-06 12:53:51 -08001066 sb->s_root->d_op = &vfat_ci_dentry_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 else
OGAWA Hirofumi1b524672008-11-06 12:53:51 -08001068 sb->s_root->d_op = &vfat_dentry_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069
Arnd Bergmann37687442010-09-14 23:07:27 +02001070 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 return 0;
1072}
1073
Al Viro152a0832010-07-25 00:46:55 +04001074static struct dentry *vfat_mount(struct file_system_type *fs_type,
David Howells454e2392006-06-23 02:02:57 -07001075 int flags, const char *dev_name,
Al Viro152a0832010-07-25 00:46:55 +04001076 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077{
Al Viro152a0832010-07-25 00:46:55 +04001078 return mount_bdev(fs_type, flags, dev_name, data, vfat_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079}
1080
1081static struct file_system_type vfat_fs_type = {
1082 .owner = THIS_MODULE,
1083 .name = "vfat",
Al Viro152a0832010-07-25 00:46:55 +04001084 .mount = vfat_mount,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 .kill_sb = kill_block_super,
1086 .fs_flags = FS_REQUIRES_DEV,
1087};
1088
1089static int __init init_vfat_fs(void)
1090{
1091 return register_filesystem(&vfat_fs_type);
1092}
1093
1094static void __exit exit_vfat_fs(void)
1095{
1096 unregister_filesystem(&vfat_fs_type);
1097}
1098
1099MODULE_LICENSE("GPL");
1100MODULE_DESCRIPTION("VFAT filesystem support");
1101MODULE_AUTHOR("Gordon Chaffee");
1102
1103module_init(init_vfat_fs)
1104module_exit(exit_vfat_fs)