blob: cb6e83557112d74e03cf00f37d6b3bddfa66cd83 [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;
312 unsigned char base[9], ext[4], buf[8], *p;
313 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
470 i = jiffies & 0xffff;
471 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) {
479 sprintf(buf, "%04X", i);
480 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) {
502 int name_len = strlen(name);
503
Alan Stern74675a52009-04-30 10:08:18 -0400504 *outlen = utf8s_to_utf16s(name, PATH_MAX, (wchar_t *) outname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
506 /*
507 * We stripped '.'s before and set len appropriately,
Alan Stern74675a52009-04-30 10:08:18 -0400508 * but utf8s_to_utf16s doesn't care about len
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 */
510 *outlen -= (name_len - len);
511
Keith Mokf22032b2008-04-28 02:16:29 -0700512 if (*outlen > 255)
513 return -ENAMETOOLONG;
514
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 op = &outname[*outlen * sizeof(wchar_t)];
516 } else {
517 if (nls) {
518 for (i = 0, ip = name, op = outname, *outlen = 0;
Keith Mokf22032b2008-04-28 02:16:29 -0700519 i < len && *outlen <= 255;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 *outlen += 1)
521 {
522 if (escape && (*ip == ':')) {
523 if (i > len - 5)
524 return -EINVAL;
525 ec = 0;
526 for (k = 1; k < 5; k++) {
527 nc = ip[k];
528 ec <<= 4;
529 if (nc >= '0' && nc <= '9') {
530 ec |= nc - '0';
531 continue;
532 }
533 if (nc >= 'a' && nc <= 'f') {
534 ec |= nc - ('a' - 10);
535 continue;
536 }
537 if (nc >= 'A' && nc <= 'F') {
538 ec |= nc - ('A' - 10);
539 continue;
540 }
541 return -EINVAL;
542 }
543 *op++ = ec & 0xFF;
544 *op++ = ec >> 8;
545 ip += 5;
546 i += 5;
547 } else {
548 if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
549 return -EINVAL;
550 ip += charlen;
551 i += charlen;
552 op += 2;
553 }
554 }
Keith Mokf22032b2008-04-28 02:16:29 -0700555 if (i < len)
556 return -ENAMETOOLONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 } else {
558 for (i = 0, ip = name, op = outname, *outlen = 0;
Keith Mokf22032b2008-04-28 02:16:29 -0700559 i < len && *outlen <= 255;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 i++, *outlen += 1)
561 {
562 *op++ = *ip++;
563 *op++ = 0;
564 }
Keith Mokf22032b2008-04-28 02:16:29 -0700565 if (i < len)
566 return -ENAMETOOLONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 }
568 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
570 *longlen = *outlen;
571 if (*outlen % 13) {
572 *op++ = 0;
573 *op++ = 0;
574 *outlen += 1;
575 if (*outlen % 13) {
576 fill = 13 - (*outlen % 13);
577 for (i = 0; i < fill; i++) {
578 *op++ = 0xff;
579 *op++ = 0xff;
580 }
581 *outlen += fill;
582 }
583 }
584
585 return 0;
586}
587
588static int vfat_build_slots(struct inode *dir, const unsigned char *name,
589 int len, int is_dir, int cluster,
590 struct timespec *ts,
591 struct msdos_dir_slot *slots, int *nr_slots)
592{
593 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
594 struct fat_mount_options *opts = &sbi->options;
595 struct msdos_dir_slot *ps;
596 struct msdos_dir_entry *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 unsigned char cksum, lcase;
598 unsigned char msdos_name[MSDOS_NAME];
599 wchar_t *uname;
600 __le16 time, date;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800601 u8 time_cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 int err, ulen, usize, i;
603 loff_t offset;
604
605 *nr_slots = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700607 uname = __getname();
608 if (!uname)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 return -ENOMEM;
610
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
612 opts->unicode_xlate, opts->utf8, sbi->nls_io);
613 if (err)
614 goto out_free;
615
616 err = vfat_is_used_badchars(uname, ulen);
617 if (err)
618 goto out_free;
619
620 err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
621 msdos_name, &lcase);
622 if (err < 0)
623 goto out_free;
624 else if (err == 1) {
625 de = (struct msdos_dir_entry *)slots;
626 err = 0;
627 goto shortname;
628 }
629
630 /* build the entry of long file name */
OGAWA Hirofumi451cbaa2005-10-30 15:03:49 -0800631 cksum = fat_checksum(msdos_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
633 *nr_slots = usize / 13;
634 for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
635 ps->id = i;
636 ps->attr = ATTR_EXT;
637 ps->reserved = 0;
638 ps->alias_checksum = cksum;
639 ps->start = 0;
640 offset = (i - 1) * 13;
641 fatwchar_to16(ps->name0_4, uname + offset, 5);
642 fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
643 fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
644 }
645 slots[0].id |= 0x40;
646 de = (struct msdos_dir_entry *)ps;
647
648shortname:
649 /* build the entry of 8.3 alias name */
650 (*nr_slots)++;
651 memcpy(de->name, msdos_name, MSDOS_NAME);
652 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
653 de->lcase = lcase;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800654 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 de->time = de->ctime = time;
656 de->date = de->cdate = de->adate = date;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800657 de->ctime_cs = time_cs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 de->start = cpu_to_le16(cluster);
659 de->starthi = cpu_to_le16(cluster >> 16);
660 de->size = 0;
661out_free:
OGAWA Hirofumic7a6c4e2008-04-28 02:16:29 -0700662 __putname(uname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 return err;
664}
665
666static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
667 int cluster, struct timespec *ts,
668 struct fat_slot_info *sinfo)
669{
670 struct msdos_dir_slot *slots;
671 unsigned int len;
672 int err, nr_slots;
673
674 len = vfat_striptail_len(qname);
675 if (len == 0)
676 return -ENOENT;
677
Linus Torvalds8f593422008-05-19 19:53:01 -0700678 slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 if (slots == NULL)
680 return -ENOMEM;
681
682 err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
683 slots, &nr_slots);
684 if (err)
685 goto cleanup;
686
687 err = fat_add_entries(dir, slots, nr_slots, sinfo);
688 if (err)
689 goto cleanup;
690
691 /* update timestamp */
692 dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
693 if (IS_DIRSYNC(dir))
694 (void)fat_sync_inode(dir);
695 else
696 mark_inode_dirty(dir);
697cleanup:
698 kfree(slots);
699 return err;
700}
701
702static int vfat_find(struct inode *dir, struct qstr *qname,
703 struct fat_slot_info *sinfo)
704{
705 unsigned int len = vfat_striptail_len(qname);
706 if (len == 0)
707 return -ENOENT;
708 return fat_search_long(dir, qname->name, len, sinfo);
709}
710
711static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
712 struct nameidata *nd)
713{
714 struct super_block *sb = dir->i_sb;
715 struct fat_slot_info sinfo;
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800716 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 struct dentry *alias;
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800718 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719
Linus Torvalds8f593422008-05-19 19:53:01 -0700720 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
722 err = vfat_find(dir, &dentry->d_name, &sinfo);
723 if (err) {
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800724 if (err == -ENOENT) {
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800725 inode = NULL;
726 goto out;
727 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 goto error;
729 }
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800730
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
732 brelse(sinfo.bh);
733 if (IS_ERR(inode)) {
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800734 err = PTR_ERR(inode);
735 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 }
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800737
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 alias = d_find_alias(inode);
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800739 if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) {
740 /*
741 * This inode has non DCACHE_DISCONNECTED dentry. This
742 * means, the user did ->lookup() by an another name
743 * (longname vs 8.3 alias of it) in past.
744 *
745 * Switch to new one for reason of locality if possible.
746 */
OGAWA Hirofumi1c13a242008-11-06 12:53:52 -0800747 BUG_ON(d_unhashed(alias));
748 if (!S_ISDIR(inode->i_mode))
749 d_move(alias, dentry);
750 iput(inode);
751 unlock_super(sb);
752 return alias;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 }
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800754out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700755 unlock_super(sb);
OGAWA Hirofumi1b524672008-11-06 12:53:51 -0800756 dentry->d_op = sb->s_root->d_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 dentry->d_time = dentry->d_parent->d_inode->i_version;
758 dentry = d_splice_alias(inode, dentry);
759 if (dentry) {
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 }
763 return dentry;
OGAWA Hirofumi068f5ae2008-11-06 12:53:51 -0800764
765error:
766 unlock_super(sb);
767 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768}
769
770static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
771 struct nameidata *nd)
772{
773 struct super_block *sb = dir->i_sb;
774 struct inode *inode;
775 struct fat_slot_info sinfo;
776 struct timespec ts;
777 int err;
778
Linus Torvalds8f593422008-05-19 19:53:01 -0700779 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780
781 ts = CURRENT_TIME_SEC;
782 err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
783 if (err)
784 goto out;
785 dir->i_version++;
786
787 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
788 brelse(sinfo.bh);
789 if (IS_ERR(inode)) {
790 err = PTR_ERR(inode);
791 goto out;
792 }
793 inode->i_version++;
794 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
795 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
796
797 dentry->d_time = dentry->d_parent->d_inode->i_version;
798 d_instantiate(dentry, inode);
799out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700800 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 return err;
802}
803
804static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
805{
806 struct inode *inode = dentry->d_inode;
Linus Torvalds8f593422008-05-19 19:53:01 -0700807 struct super_block *sb = dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 struct fat_slot_info sinfo;
809 int err;
810
Linus Torvalds8f593422008-05-19 19:53:01 -0700811 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812
813 err = fat_dir_empty(inode);
814 if (err)
815 goto out;
816 err = vfat_find(dir, &dentry->d_name, &sinfo);
817 if (err)
818 goto out;
819
820 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
821 if (err)
822 goto out;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700823 drop_nlink(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
Dave Hansence71ec32006-09-30 23:29:06 -0700825 clear_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
827 fat_detach(inode);
828out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700829 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
831 return err;
832}
833
834static int vfat_unlink(struct inode *dir, struct dentry *dentry)
835{
836 struct inode *inode = dentry->d_inode;
Linus Torvalds8f593422008-05-19 19:53:01 -0700837 struct super_block *sb = dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 struct fat_slot_info sinfo;
839 int err;
840
Linus Torvalds8f593422008-05-19 19:53:01 -0700841 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 err = vfat_find(dir, &dentry->d_name, &sinfo);
844 if (err)
845 goto out;
846
847 err = fat_remove_entries(dir, &sinfo); /* and releases bh */
848 if (err)
849 goto out;
Dave Hansence71ec32006-09-30 23:29:06 -0700850 clear_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
852 fat_detach(inode);
853out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700854 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855
856 return err;
857}
858
859static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
860{
861 struct super_block *sb = dir->i_sb;
862 struct inode *inode;
863 struct fat_slot_info sinfo;
864 struct timespec ts;
865 int err, cluster;
866
Linus Torvalds8f593422008-05-19 19:53:01 -0700867 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868
869 ts = CURRENT_TIME_SEC;
870 cluster = fat_alloc_new_dir(dir, &ts);
871 if (cluster < 0) {
872 err = cluster;
873 goto out;
874 }
875 err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
876 if (err)
877 goto out_free;
878 dir->i_version++;
Dave Hansend8c76e62006-09-30 23:29:04 -0700879 inc_nlink(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
881 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
882 brelse(sinfo.bh);
883 if (IS_ERR(inode)) {
884 err = PTR_ERR(inode);
885 /* the directory was completed, just return a error */
886 goto out;
887 }
888 inode->i_version++;
889 inode->i_nlink = 2;
890 inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
891 /* timestamp is already written, so mark_inode_dirty() is unneeded. */
892
893 dentry->d_time = dentry->d_parent->d_inode->i_version;
894 d_instantiate(dentry, inode);
895
Linus Torvalds8f593422008-05-19 19:53:01 -0700896 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 return 0;
898
899out_free:
900 fat_free_clusters(dir, cluster);
901out:
Linus Torvalds8f593422008-05-19 19:53:01 -0700902 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 return err;
904}
905
906static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
907 struct inode *new_dir, struct dentry *new_dentry)
908{
909 struct buffer_head *dotdot_bh;
910 struct msdos_dir_entry *dotdot_de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 struct inode *old_inode, *new_inode;
912 struct fat_slot_info old_sinfo, sinfo;
913 struct timespec ts;
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800914 loff_t dotdot_i_pos, new_i_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 int err, is_dir, update_dotdot, corrupt = 0;
Linus Torvalds8f593422008-05-19 19:53:01 -0700916 struct super_block *sb = old_dir->i_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917
918 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
919 old_inode = old_dentry->d_inode;
920 new_inode = new_dentry->d_inode;
Linus Torvalds8f593422008-05-19 19:53:01 -0700921 lock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
923 if (err)
924 goto out;
925
926 is_dir = S_ISDIR(old_inode->i_mode);
927 update_dotdot = (is_dir && old_dir != new_dir);
928 if (update_dotdot) {
929 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
930 &dotdot_i_pos) < 0) {
931 err = -EIO;
932 goto out;
933 }
934 }
935
936 ts = CURRENT_TIME_SEC;
937 if (new_inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 if (is_dir) {
939 err = fat_dir_empty(new_inode);
940 if (err)
941 goto out;
942 }
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800943 new_i_pos = MSDOS_I(new_inode)->i_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 fat_detach(new_inode);
945 } else {
946 err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
947 &ts, &sinfo);
948 if (err)
949 goto out;
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800950 new_i_pos = sinfo.i_pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 }
952 new_dir->i_version++;
953
954 fat_detach(old_inode);
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -0800955 fat_attach(old_inode, new_i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 if (IS_DIRSYNC(new_dir)) {
957 err = fat_sync_inode(old_inode);
958 if (err)
959 goto error_inode;
960 } else
961 mark_inode_dirty(old_inode);
962
963 if (update_dotdot) {
964 int start = MSDOS_I(new_dir)->i_logstart;
965 dotdot_de->start = cpu_to_le16(start);
966 dotdot_de->starthi = cpu_to_le16(start >> 16);
Al Virob5224122009-06-07 13:44:36 -0400967 mark_buffer_dirty_inode(dotdot_bh, old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 if (IS_DIRSYNC(new_dir)) {
969 err = sync_dirty_buffer(dotdot_bh);
970 if (err)
971 goto error_dotdot;
972 }
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700973 drop_nlink(old_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 if (!new_inode)
Dave Hansend8c76e62006-09-30 23:29:04 -0700975 inc_nlink(new_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 }
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) {
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700990 drop_nlink(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 if (is_dir)
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700992 drop_nlink(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 new_inode->i_ctime = ts;
994 }
995out:
996 brelse(sinfo.bh);
997 brelse(dotdot_bh);
998 brelse(old_sinfo.bh);
Linus Torvalds8f593422008-05-19 19:53:01 -0700999 unlock_super(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
1001 return err;
1002
1003error_dotdot:
1004 /* data cluster is shared, serious corruption */
1005 corrupt = 1;
1006
1007 if (update_dotdot) {
1008 int start = MSDOS_I(old_dir)->i_logstart;
1009 dotdot_de->start = cpu_to_le16(start);
1010 dotdot_de->starthi = cpu_to_le16(start >> 16);
Al Virob5224122009-06-07 13:44:36 -04001011 mark_buffer_dirty_inode(dotdot_bh, old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 corrupt |= sync_dirty_buffer(dotdot_bh);
1013 }
1014error_inode:
1015 fat_detach(old_inode);
1016 fat_attach(old_inode, old_sinfo.i_pos);
1017 if (new_inode) {
OGAWA Hirofumi9131dd42005-10-30 15:03:50 -08001018 fat_attach(new_inode, new_i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 if (corrupt)
1020 corrupt |= fat_sync_inode(new_inode);
1021 } else {
1022 /*
1023 * If new entry was not sharing the data cluster, it
1024 * shouldn't be serious corruption.
1025 */
1026 int err2 = fat_remove_entries(new_dir, &sinfo);
1027 if (corrupt)
1028 corrupt |= err2;
1029 sinfo.bh = NULL;
1030 }
1031 if (corrupt < 0) {
Denis Karpov85c78592009-06-04 02:34:22 +09001032 fat_fs_error(new_dir->i_sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 "%s: Filesystem corrupted (i_pos %lld)",
Harvey Harrison8e24eea2008-04-30 00:55:09 -07001034 __func__, sinfo.i_pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 }
1036 goto out;
1037}
1038
Arjan van de Venc5ef1c42007-02-12 00:55:40 -08001039static const struct inode_operations vfat_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 .create = vfat_create,
1041 .lookup = vfat_lookup,
1042 .unlink = vfat_unlink,
1043 .mkdir = vfat_mkdir,
1044 .rmdir = vfat_rmdir,
1045 .rename = vfat_rename,
OGAWA Hirofumi1278fdd2008-04-28 02:16:25 -07001046 .setattr = fat_setattr,
OGAWA Hirofumida63fc72006-11-16 01:19:28 -08001047 .getattr = fat_getattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048};
1049
1050static int vfat_fill_super(struct super_block *sb, void *data, int silent)
1051{
1052 int res;
1053
1054 res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
1055 if (res)
1056 return res;
1057
1058 if (MSDOS_SB(sb)->options.name_check != 's')
OGAWA Hirofumi1b524672008-11-06 12:53:51 -08001059 sb->s_root->d_op = &vfat_ci_dentry_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 else
OGAWA Hirofumi1b524672008-11-06 12:53:51 -08001061 sb->s_root->d_op = &vfat_dentry_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062
1063 return 0;
1064}
1065
David Howells454e2392006-06-23 02:02:57 -07001066static int vfat_get_sb(struct file_system_type *fs_type,
1067 int flags, const char *dev_name,
1068 void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069{
David Howells454e2392006-06-23 02:02:57 -07001070 return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
1071 mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072}
1073
1074static struct file_system_type vfat_fs_type = {
1075 .owner = THIS_MODULE,
1076 .name = "vfat",
1077 .get_sb = vfat_get_sb,
1078 .kill_sb = kill_block_super,
1079 .fs_flags = FS_REQUIRES_DEV,
1080};
1081
1082static int __init init_vfat_fs(void)
1083{
1084 return register_filesystem(&vfat_fs_type);
1085}
1086
1087static void __exit exit_vfat_fs(void)
1088{
1089 unregister_filesystem(&vfat_fs_type);
1090}
1091
1092MODULE_LICENSE("GPL");
1093MODULE_DESCRIPTION("VFAT filesystem support");
1094MODULE_AUTHOR("Gordon Chaffee");
1095
1096module_init(init_vfat_fs)
1097module_exit(exit_vfat_fs)