1 /* 2 * linux/fs/vfat/namei.c 3 * 4 * Written 1992,1993 by Werner Almesberger 5 * 6 * Windows95/Windows NT compatible extended MSDOS filesystem 7 * by Gordon Chaffee Copyright (C) 1995. Send bug reports for the 8 * VFAT filesystem to <chaffee@cs.berkeley.edu>. Specify 9 * what file operation caused you trouble and if you can duplicate 10 * the problem, send a script that demonstrates it. 11 * 12 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de> 13 * 14 * Support Multibyte characters and cleanup by 15 * OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> 16 */ 17 18 #include <linux/module.h> 19 #include <linux/jiffies.h> 20 #include <linux/ctype.h> 21 #include <linux/slab.h> 22 #include <linux/buffer_head.h> 23 #include <linux/namei.h> 24 #include "fat.h" 25 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) 35 { 36 int ret = 1; 37 spin_lock(&dentry->d_lock); 38 if (dentry->d_time != dentry->d_parent->d_inode->i_version) 39 ret = 0; 40 spin_unlock(&dentry->d_lock); 41 return ret; 42 } 43 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))) { 80 if (nd->flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) 81 return 0; 82 } 83 84 return vfat_revalidate_shortname(dentry); 85 } 86 87 /* returns the length of a struct qstr, ignoring trailing dots */ 88 static 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 */ 103 static 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 */ 115 static 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 */ 136 static 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 */ 154 static 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 } 167 168 static const struct dentry_operations vfat_ci_dentry_ops = { 169 .d_revalidate = vfat_revalidate_ci, 170 .d_hash = vfat_hashi, 171 .d_compare = vfat_cmpi, 172 }; 173 174 static const struct dentry_operations vfat_dentry_ops = { 175 .d_revalidate = vfat_revalidate, 176 .d_hash = vfat_hash, 177 .d_compare = vfat_cmp, 178 }; 179 180 /* Characters that are undesirable in an MS-DOS file name */ 181 182 static 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 } 189 190 static inline wchar_t vfat_replace_char(wchar_t w) 191 { 192 return (w == '[') || (w == ']') || (w == ';') || (w == ',') 193 || (w == '+') || (w == '='); 194 } 195 196 static wchar_t vfat_skip_char(wchar_t w) 197 { 198 return (w == '.') || (w == ' '); 199 } 200 201 static 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; 208 209 if (s[i - 1] == ' ') /* last character cannot be space */ 210 return -EINVAL; 211 212 return 0; 213 } 214 215 static 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 */ 245 struct 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) 255 256 static 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 */ 306 static 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 */ 489 static int 490 xlate_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); 503 504 *outlen = utf8s_to_utf16s(name, PATH_MAX, (wchar_t *) outname); 505 506 /* 507 * We stripped '.'s before and set len appropriately, 508 * but utf8s_to_utf16s doesn't care about len 509 */ 510 *outlen -= (name_len - len); 511 512 if (*outlen > 255) 513 return -ENAMETOOLONG; 514 515 op = &outname[*outlen * sizeof(wchar_t)]; 516 } else { 517 if (nls) { 518 for (i = 0, ip = name, op = outname, *outlen = 0; 519 i < len && *outlen <= 255; 520 *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 } 555 if (i < len) 556 return -ENAMETOOLONG; 557 } else { 558 for (i = 0, ip = name, op = outname, *outlen = 0; 559 i < len && *outlen <= 255; 560 i++, *outlen += 1) 561 { 562 *op++ = *ip++; 563 *op++ = 0; 564 } 565 if (i < len) 566 return -ENAMETOOLONG; 567 } 568 } 569 570 *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 } 587 588 static 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; 597 unsigned char cksum, lcase; 598 unsigned char msdos_name[MSDOS_NAME]; 599 wchar_t *uname; 600 __le16 time, date; 601 u8 time_cs; 602 int err, ulen, usize, i; 603 loff_t offset; 604 605 *nr_slots = 0; 606 607 uname = __getname(); 608 if (!uname) 609 return -ENOMEM; 610 611 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 */ 631 cksum = fat_checksum(msdos_name); 632 633 *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; 647 648 shortname: 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; 654 fat_time_unix2fat(sbi, ts, &time, &date, &time_cs); 655 de->time = de->ctime = time; 656 de->date = de->cdate = de->adate = date; 657 de->ctime_cs = time_cs; 658 de->start = cpu_to_le16(cluster); 659 de->starthi = cpu_to_le16(cluster >> 16); 660 de->size = 0; 661 out_free: 662 __putname(uname); 663 return err; 664 } 665 666 static 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; 677 678 slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS); 679 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); 697 cleanup: 698 kfree(slots); 699 return err; 700 } 701 702 static 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 } 710 711 static 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; 716 struct inode *inode; 717 struct dentry *alias; 718 int err; 719 720 lock_super(sb); 721 722 err = vfat_find(dir, &dentry->d_name, &sinfo); 723 if (err) { 724 if (err == -ENOENT) { 725 inode = NULL; 726 goto out; 727 } 728 goto error; 729 } 730 731 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); 732 brelse(sinfo.bh); 733 if (IS_ERR(inode)) { 734 err = PTR_ERR(inode); 735 goto error; 736 } 737 738 alias = d_find_alias(inode); 739 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 */ 747 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; 753 } 754 out: 755 unlock_super(sb); 756 dentry->d_op = sb->s_root->d_op; 757 dentry->d_time = dentry->d_parent->d_inode->i_version; 758 dentry = d_splice_alias(inode, dentry); 759 if (dentry) { 760 dentry->d_op = sb->s_root->d_op; 761 dentry->d_time = dentry->d_parent->d_inode->i_version; 762 } 763 return dentry; 764 765 error: 766 unlock_super(sb); 767 return ERR_PTR(err); 768 } 769 770 static 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; 778 779 lock_super(sb); 780 781 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); 799 out: 800 unlock_super(sb); 801 return err; 802 } 803 804 static int vfat_rmdir(struct inode *dir, struct dentry *dentry) 805 { 806 struct inode *inode = dentry->d_inode; 807 struct super_block *sb = dir->i_sb; 808 struct fat_slot_info sinfo; 809 int err; 810 811 lock_super(sb); 812 813 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; 823 drop_nlink(dir); 824 825 clear_nlink(inode); 826 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; 827 fat_detach(inode); 828 out: 829 unlock_super(sb); 830 831 return err; 832 } 833 834 static int vfat_unlink(struct inode *dir, struct dentry *dentry) 835 { 836 struct inode *inode = dentry->d_inode; 837 struct super_block *sb = dir->i_sb; 838 struct fat_slot_info sinfo; 839 int err; 840 841 lock_super(sb); 842 843 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; 850 clear_nlink(inode); 851 inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC; 852 fat_detach(inode); 853 out: 854 unlock_super(sb); 855 856 return err; 857 } 858 859 static 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; 866 867 lock_super(sb); 868 869 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++; 879 inc_nlink(dir); 880 881 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); 895 896 unlock_super(sb); 897 return 0; 898 899 out_free: 900 fat_free_clusters(dir, cluster); 901 out: 902 unlock_super(sb); 903 return err; 904 } 905 906 static 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; 911 struct inode *old_inode, *new_inode; 912 struct fat_slot_info old_sinfo, sinfo; 913 struct timespec ts; 914 loff_t dotdot_i_pos, new_i_pos; 915 int err, is_dir, update_dotdot, corrupt = 0; 916 struct super_block *sb = old_dir->i_sb; 917 918 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; 919 old_inode = old_dentry->d_inode; 920 new_inode = new_dentry->d_inode; 921 lock_super(sb); 922 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) { 938 if (is_dir) { 939 err = fat_dir_empty(new_inode); 940 if (err) 941 goto out; 942 } 943 new_i_pos = MSDOS_I(new_inode)->i_pos; 944 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; 950 new_i_pos = sinfo.i_pos; 951 } 952 new_dir->i_version++; 953 954 fat_detach(old_inode); 955 fat_attach(old_inode, new_i_pos); 956 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); 967 mark_buffer_dirty_inode(dotdot_bh, old_inode); 968 if (IS_DIRSYNC(new_dir)) { 969 err = sync_dirty_buffer(dotdot_bh); 970 if (err) 971 goto error_dotdot; 972 } 973 drop_nlink(old_dir); 974 if (!new_inode) 975 inc_nlink(new_dir); 976 } 977 978 err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ 979 old_sinfo.bh = NULL; 980 if (err) 981 goto error_dotdot; 982 old_dir->i_version++; 983 old_dir->i_ctime = old_dir->i_mtime = ts; 984 if (IS_DIRSYNC(old_dir)) 985 (void)fat_sync_inode(old_dir); 986 else 987 mark_inode_dirty(old_dir); 988 989 if (new_inode) { 990 drop_nlink(new_inode); 991 if (is_dir) 992 drop_nlink(new_inode); 993 new_inode->i_ctime = ts; 994 } 995 out: 996 brelse(sinfo.bh); 997 brelse(dotdot_bh); 998 brelse(old_sinfo.bh); 999 unlock_super(sb); 1000 1001 return err; 1002 1003 error_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); 1011 mark_buffer_dirty_inode(dotdot_bh, old_inode); 1012 corrupt |= sync_dirty_buffer(dotdot_bh); 1013 } 1014 error_inode: 1015 fat_detach(old_inode); 1016 fat_attach(old_inode, old_sinfo.i_pos); 1017 if (new_inode) { 1018 fat_attach(new_inode, new_i_pos); 1019 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) { 1032 fat_fs_error(new_dir->i_sb, 1033 "%s: Filesystem corrupted (i_pos %lld)", 1034 __func__, sinfo.i_pos); 1035 } 1036 goto out; 1037 } 1038 1039 static const struct inode_operations vfat_dir_inode_operations = { 1040 .create = vfat_create, 1041 .lookup = vfat_lookup, 1042 .unlink = vfat_unlink, 1043 .mkdir = vfat_mkdir, 1044 .rmdir = vfat_rmdir, 1045 .rename = vfat_rename, 1046 .setattr = fat_setattr, 1047 .getattr = fat_getattr, 1048 }; 1049 1050 static 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') 1059 sb->s_root->d_op = &vfat_ci_dentry_ops; 1060 else 1061 sb->s_root->d_op = &vfat_dentry_ops; 1062 1063 return 0; 1064 } 1065 1066 static int vfat_get_sb(struct file_system_type *fs_type, 1067 int flags, const char *dev_name, 1068 void *data, struct vfsmount *mnt) 1069 { 1070 return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super, 1071 mnt); 1072 } 1073 1074 static 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 1082 static int __init init_vfat_fs(void) 1083 { 1084 return register_filesystem(&vfat_fs_type); 1085 } 1086 1087 static void __exit exit_vfat_fs(void) 1088 { 1089 unregister_filesystem(&vfat_fs_type); 1090 } 1091 1092 MODULE_LICENSE("GPL"); 1093 MODULE_DESCRIPTION("VFAT filesystem support"); 1094 MODULE_AUTHOR("Gordon Chaffee"); 1095 1096 module_init(init_vfat_fs) 1097 module_exit(exit_vfat_fs) 1098