1 /* 2 * linux/fs/fat/dir.c 3 * 4 * directory handling functions for fat-based filesystems 5 * 6 * Written 1992,1993 by Werner Almesberger 7 * 8 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu> 9 * 10 * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu> 11 * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk> 12 * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV 13 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de> 14 */ 15 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/time.h> 19 #include <linux/msdos_fs.h> 20 #include <linux/dirent.h> 21 #include <linux/smp_lock.h> 22 #include <linux/buffer_head.h> 23 #include <asm/uaccess.h> 24 25 static inline loff_t fat_make_i_pos(struct super_block *sb, 26 struct buffer_head *bh, 27 struct msdos_dir_entry *de) 28 { 29 return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits) 30 | (de - (struct msdos_dir_entry *)bh->b_data); 31 } 32 33 static inline void fat_dir_readahead(struct inode *dir, sector_t iblock, 34 sector_t phys) 35 { 36 struct super_block *sb = dir->i_sb; 37 struct msdos_sb_info *sbi = MSDOS_SB(sb); 38 struct buffer_head *bh; 39 int sec; 40 41 /* This is not a first sector of cluster, or sec_per_clus == 1 */ 42 if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1) 43 return; 44 /* root dir of FAT12/FAT16 */ 45 if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO)) 46 return; 47 48 bh = sb_getblk(sb, phys); 49 if (bh && !buffer_uptodate(bh)) { 50 for (sec = 0; sec < sbi->sec_per_clus; sec++) 51 sb_breadahead(sb, phys + sec); 52 } 53 brelse(bh); 54 } 55 56 /* Returns the inode number of the directory entry at offset pos. If bh is 57 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is 58 returned in bh. 59 AV. Most often we do it item-by-item. Makes sense to optimize. 60 AV. OK, there we go: if both bh and de are non-NULL we assume that we just 61 AV. want the next entry (took one explicit de=NULL in vfat/namei.c). 62 AV. It's done in fat_get_entry() (inlined), here the slow case lives. 63 AV. Additionally, when we return -1 (i.e. reached the end of directory) 64 AV. we make bh NULL. 65 */ 66 static int fat__get_entry(struct inode *dir, loff_t *pos, 67 struct buffer_head **bh, struct msdos_dir_entry **de) 68 { 69 struct super_block *sb = dir->i_sb; 70 sector_t phys, iblock; 71 int offset; 72 int err; 73 74 next: 75 if (*bh) 76 brelse(*bh); 77 78 *bh = NULL; 79 iblock = *pos >> sb->s_blocksize_bits; 80 err = fat_bmap(dir, iblock, &phys); 81 if (err || !phys) 82 return -1; /* beyond EOF or error */ 83 84 fat_dir_readahead(dir, iblock, phys); 85 86 *bh = sb_bread(sb, phys); 87 if (*bh == NULL) { 88 printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n", 89 (unsigned long long)phys); 90 /* skip this block */ 91 *pos = (iblock + 1) << sb->s_blocksize_bits; 92 goto next; 93 } 94 95 offset = *pos & (sb->s_blocksize - 1); 96 *pos += sizeof(struct msdos_dir_entry); 97 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset); 98 99 return 0; 100 } 101 102 static inline int fat_get_entry(struct inode *dir, loff_t *pos, 103 struct buffer_head **bh, 104 struct msdos_dir_entry **de) 105 { 106 /* Fast stuff first */ 107 if (*bh && *de && 108 (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) { 109 *pos += sizeof(struct msdos_dir_entry); 110 (*de)++; 111 return 0; 112 } 113 return fat__get_entry(dir, pos, bh, de); 114 } 115 116 /* 117 * Convert Unicode 16 to UTF8, translated Unicode, or ASCII. 118 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a 119 * colon as an escape character since it is normally invalid on the vfat 120 * filesystem. The following four characters are the hexadecimal digits 121 * of Unicode value. This lets us do a full dump and restore of Unicode 122 * filenames. We could get into some trouble with long Unicode names, 123 * but ignore that right now. 124 * Ahem... Stack smashing in ring 0 isn't fun. Fixed. 125 */ 126 static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate, 127 struct nls_table *nls) 128 { 129 wchar_t *ip, ec; 130 unsigned char *op, nc; 131 int charlen; 132 int k; 133 134 ip = uni; 135 op = ascii; 136 137 while (*ip) { 138 ec = *ip++; 139 if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) { 140 op += charlen; 141 } else { 142 if (uni_xlate == 1) { 143 *op = ':'; 144 for (k = 4; k > 0; k--) { 145 nc = ec & 0xF; 146 op[k] = nc > 9 ? nc + ('a' - 10) 147 : nc + '0'; 148 ec >>= 4; 149 } 150 op += 5; 151 } else { 152 *op++ = '?'; 153 } 154 } 155 /* We have some slack there, so it's OK */ 156 if (op>ascii+256) { 157 op = ascii + 256; 158 break; 159 } 160 } 161 *op = 0; 162 return (op - ascii); 163 } 164 165 static inline int 166 fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni) 167 { 168 int charlen; 169 170 charlen = t->char2uni(c, clen, uni); 171 if (charlen < 0) { 172 *uni = 0x003f; /* a question mark */ 173 charlen = 1; 174 } 175 return charlen; 176 } 177 178 static inline int 179 fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni) 180 { 181 int charlen; 182 wchar_t wc; 183 184 charlen = t->char2uni(c, clen, &wc); 185 if (charlen < 0) { 186 *uni = 0x003f; /* a question mark */ 187 charlen = 1; 188 } else if (charlen <= 1) { 189 unsigned char nc = t->charset2lower[*c]; 190 191 if (!nc) 192 nc = *c; 193 194 if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) { 195 *uni = 0x003f; /* a question mark */ 196 charlen = 1; 197 } 198 } else 199 *uni = wc; 200 201 return charlen; 202 } 203 204 static inline int 205 fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size, 206 wchar_t *uni_buf, unsigned short opt, int lower) 207 { 208 int len = 0; 209 210 if (opt & VFAT_SFN_DISPLAY_LOWER) 211 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf); 212 else if (opt & VFAT_SFN_DISPLAY_WIN95) 213 len = fat_short2uni(nls, buf, buf_size, uni_buf); 214 else if (opt & VFAT_SFN_DISPLAY_WINNT) { 215 if (lower) 216 len = fat_short2lower_uni(nls, buf, buf_size, uni_buf); 217 else 218 len = fat_short2uni(nls, buf, buf_size, uni_buf); 219 } else 220 len = fat_short2uni(nls, buf, buf_size, uni_buf); 221 222 return len; 223 } 224 225 enum { PARSE_INVALID = 1, PARSE_NOT_LONGNAME, PARSE_EOF, }; 226 227 /** 228 * fat_parse_long - Parse extended directory entry. 229 * 230 * This function returns zero on success, negative value on error, or one of 231 * the following: 232 * 233 * %PARSE_INVALID - Directory entry is invalid. 234 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname. 235 * %PARSE_EOF - Directory has no more entries. 236 */ 237 static int fat_parse_long(struct inode *dir, loff_t *pos, 238 struct buffer_head **bh, struct msdos_dir_entry **de, 239 wchar_t **unicode, unsigned char *nr_slots) 240 { 241 struct msdos_dir_slot *ds; 242 unsigned char id, slot, slots, alias_checksum; 243 244 if (!*unicode) { 245 *unicode = (wchar_t *)__get_free_page(GFP_KERNEL); 246 if (!*unicode) { 247 brelse(*bh); 248 return -ENOMEM; 249 } 250 } 251 parse_long: 252 slots = 0; 253 ds = (struct msdos_dir_slot *)*de; 254 id = ds->id; 255 if (!(id & 0x40)) 256 return PARSE_INVALID; 257 slots = id & ~0x40; 258 if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */ 259 return PARSE_INVALID; 260 *nr_slots = slots; 261 alias_checksum = ds->alias_checksum; 262 263 slot = slots; 264 while (1) { 265 int offset; 266 267 slot--; 268 offset = slot * 13; 269 fat16_towchar(*unicode + offset, ds->name0_4, 5); 270 fat16_towchar(*unicode + offset + 5, ds->name5_10, 6); 271 fat16_towchar(*unicode + offset + 11, ds->name11_12, 2); 272 273 if (ds->id & 0x40) 274 (*unicode)[offset + 13] = 0; 275 if (fat_get_entry(dir, pos, bh, de) < 0) 276 return PARSE_EOF; 277 if (slot == 0) 278 break; 279 ds = (struct msdos_dir_slot *)*de; 280 if (ds->attr != ATTR_EXT) 281 return PARSE_NOT_LONGNAME; 282 if ((ds->id & ~0x40) != slot) 283 goto parse_long; 284 if (ds->alias_checksum != alias_checksum) 285 goto parse_long; 286 } 287 if ((*de)->name[0] == DELETED_FLAG) 288 return PARSE_INVALID; 289 if ((*de)->attr == ATTR_EXT) 290 goto parse_long; 291 if (IS_FREE((*de)->name) || ((*de)->attr & ATTR_VOLUME)) 292 return PARSE_INVALID; 293 if (fat_checksum((*de)->name) != alias_checksum) 294 *nr_slots = 0; 295 296 return 0; 297 } 298 299 /* 300 * Return values: negative -> error, 0 -> not found, positive -> found, 301 * value is the total amount of slots, including the shortname entry. 302 */ 303 int fat_search_long(struct inode *inode, const unsigned char *name, 304 int name_len, struct fat_slot_info *sinfo) 305 { 306 struct super_block *sb = inode->i_sb; 307 struct msdos_sb_info *sbi = MSDOS_SB(sb); 308 struct buffer_head *bh = NULL; 309 struct msdos_dir_entry *de; 310 struct nls_table *nls_io = sbi->nls_io; 311 struct nls_table *nls_disk = sbi->nls_disk; 312 wchar_t bufuname[14]; 313 unsigned char xlate_len, nr_slots; 314 wchar_t *unicode = NULL; 315 unsigned char work[8], bufname[260]; /* 256 + 4 */ 316 int uni_xlate = sbi->options.unicode_xlate; 317 int utf8 = sbi->options.utf8; 318 int anycase = (sbi->options.name_check != 's'); 319 unsigned short opt_shortname = sbi->options.shortname; 320 loff_t cpos = 0; 321 int chl, i, j, last_u, err; 322 323 err = -ENOENT; 324 while(1) { 325 if (fat_get_entry(inode, &cpos, &bh, &de) == -1) 326 goto EODir; 327 parse_record: 328 nr_slots = 0; 329 if (de->name[0] == DELETED_FLAG) 330 continue; 331 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME)) 332 continue; 333 if (de->attr != ATTR_EXT && IS_FREE(de->name)) 334 continue; 335 if (de->attr == ATTR_EXT) { 336 int status = fat_parse_long(inode, &cpos, &bh, &de, 337 &unicode, &nr_slots); 338 if (status < 0) 339 return status; 340 else if (status == PARSE_INVALID) 341 continue; 342 else if (status == PARSE_NOT_LONGNAME) 343 goto parse_record; 344 else if (status == PARSE_EOF) 345 goto EODir; 346 } 347 348 memcpy(work, de->name, sizeof(de->name)); 349 /* see namei.c, msdos_format_name */ 350 if (work[0] == 0x05) 351 work[0] = 0xE5; 352 for (i = 0, j = 0, last_u = 0; i < 8;) { 353 if (!work[i]) break; 354 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i, 355 &bufuname[j++], opt_shortname, 356 de->lcase & CASE_LOWER_BASE); 357 if (chl <= 1) { 358 if (work[i] != ' ') 359 last_u = j; 360 } else { 361 last_u = j; 362 } 363 i += chl; 364 } 365 j = last_u; 366 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]); 367 for (i = 0; i < 3;) { 368 if (!de->ext[i]) break; 369 chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i, 370 &bufuname[j++], opt_shortname, 371 de->lcase & CASE_LOWER_EXT); 372 if (chl <= 1) { 373 if (de->ext[i] != ' ') 374 last_u = j; 375 } else { 376 last_u = j; 377 } 378 i += chl; 379 } 380 if (!last_u) 381 continue; 382 383 bufuname[last_u] = 0x0000; 384 xlate_len = utf8 385 ?utf8_wcstombs(bufname, bufuname, sizeof(bufname)) 386 :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io); 387 if (xlate_len == name_len) 388 if ((!anycase && !memcmp(name, bufname, xlate_len)) || 389 (anycase && !nls_strnicmp(nls_io, name, bufname, 390 xlate_len))) 391 goto Found; 392 393 if (nr_slots) { 394 xlate_len = utf8 395 ?utf8_wcstombs(bufname, unicode, sizeof(bufname)) 396 :uni16_to_x8(bufname, unicode, uni_xlate, nls_io); 397 if (xlate_len != name_len) 398 continue; 399 if ((!anycase && !memcmp(name, bufname, xlate_len)) || 400 (anycase && !nls_strnicmp(nls_io, name, bufname, 401 xlate_len))) 402 goto Found; 403 } 404 } 405 406 Found: 407 nr_slots++; /* include the de */ 408 sinfo->slot_off = cpos - nr_slots * sizeof(*de); 409 sinfo->nr_slots = nr_slots; 410 sinfo->de = de; 411 sinfo->bh = bh; 412 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de); 413 err = 0; 414 EODir: 415 if (unicode) 416 free_page((unsigned long)unicode); 417 418 return err; 419 } 420 421 EXPORT_SYMBOL(fat_search_long); 422 423 struct fat_ioctl_filldir_callback { 424 struct dirent __user *dirent; 425 int result; 426 /* for dir ioctl */ 427 const char *longname; 428 int long_len; 429 const char *shortname; 430 int short_len; 431 }; 432 433 static int __fat_readdir(struct inode *inode, struct file *filp, void *dirent, 434 filldir_t filldir, int short_only, int both) 435 { 436 struct super_block *sb = inode->i_sb; 437 struct msdos_sb_info *sbi = MSDOS_SB(sb); 438 struct buffer_head *bh; 439 struct msdos_dir_entry *de; 440 struct nls_table *nls_io = sbi->nls_io; 441 struct nls_table *nls_disk = sbi->nls_disk; 442 unsigned char long_slots; 443 const char *fill_name; 444 int fill_len; 445 wchar_t bufuname[14]; 446 wchar_t *unicode = NULL; 447 unsigned char c, work[8], bufname[56], *ptname = bufname; 448 unsigned long lpos, dummy, *furrfu = &lpos; 449 int uni_xlate = sbi->options.unicode_xlate; 450 int isvfat = sbi->options.isvfat; 451 int utf8 = sbi->options.utf8; 452 int nocase = sbi->options.nocase; 453 unsigned short opt_shortname = sbi->options.shortname; 454 unsigned long inum; 455 int chi, chl, i, i2, j, last, last_u, dotoffset = 0; 456 loff_t cpos; 457 int ret = 0; 458 459 lock_kernel(); 460 461 cpos = filp->f_pos; 462 /* Fake . and .. for the root directory. */ 463 if (inode->i_ino == MSDOS_ROOT_INO) { 464 while (cpos < 2) { 465 if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0) 466 goto out; 467 cpos++; 468 filp->f_pos++; 469 } 470 if (cpos == 2) { 471 dummy = 2; 472 furrfu = &dummy; 473 cpos = 0; 474 } 475 } 476 if (cpos & (sizeof(struct msdos_dir_entry)-1)) { 477 ret = -ENOENT; 478 goto out; 479 } 480 481 bh = NULL; 482 GetNew: 483 if (fat_get_entry(inode, &cpos, &bh, &de) == -1) 484 goto EODir; 485 parse_record: 486 long_slots = 0; 487 /* Check for long filename entry */ 488 if (isvfat) { 489 if (de->name[0] == DELETED_FLAG) 490 goto RecEnd; 491 if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME)) 492 goto RecEnd; 493 if (de->attr != ATTR_EXT && IS_FREE(de->name)) 494 goto RecEnd; 495 } else { 496 if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name)) 497 goto RecEnd; 498 } 499 500 if (isvfat && de->attr == ATTR_EXT) { 501 int status = fat_parse_long(inode, &cpos, &bh, &de, 502 &unicode, &long_slots); 503 if (status < 0) { 504 filp->f_pos = cpos; 505 ret = status; 506 goto out; 507 } else if (status == PARSE_INVALID) 508 goto RecEnd; 509 else if (status == PARSE_NOT_LONGNAME) 510 goto parse_record; 511 else if (status == PARSE_EOF) 512 goto EODir; 513 } 514 515 if (sbi->options.dotsOK) { 516 ptname = bufname; 517 dotoffset = 0; 518 if (de->attr & ATTR_HIDDEN) { 519 *ptname++ = '.'; 520 dotoffset = 1; 521 } 522 } 523 524 memcpy(work, de->name, sizeof(de->name)); 525 /* see namei.c, msdos_format_name */ 526 if (work[0] == 0x05) 527 work[0] = 0xE5; 528 for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) { 529 if (!(c = work[i])) break; 530 chl = fat_shortname2uni(nls_disk, &work[i], 8 - i, 531 &bufuname[j++], opt_shortname, 532 de->lcase & CASE_LOWER_BASE); 533 if (chl <= 1) { 534 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c; 535 if (c != ' ') { 536 last = i; 537 last_u = j; 538 } 539 } else { 540 last_u = j; 541 for (chi = 0; chi < chl && i < 8; chi++) { 542 ptname[i] = work[i]; 543 i++; last = i; 544 } 545 } 546 } 547 i = last; 548 j = last_u; 549 fat_short2uni(nls_disk, ".", 1, &bufuname[j++]); 550 ptname[i++] = '.'; 551 for (i2 = 0; i2 < 3;) { 552 if (!(c = de->ext[i2])) break; 553 chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2, 554 &bufuname[j++], opt_shortname, 555 de->lcase & CASE_LOWER_EXT); 556 if (chl <= 1) { 557 i2++; 558 ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c; 559 if (c != ' ') { 560 last = i; 561 last_u = j; 562 } 563 } else { 564 last_u = j; 565 for (chi = 0; chi < chl && i2 < 3; chi++) { 566 ptname[i++] = de->ext[i2++]; 567 last = i; 568 } 569 } 570 } 571 if (!last) 572 goto RecEnd; 573 574 i = last + dotoffset; 575 j = last_u; 576 577 lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry); 578 if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME)) 579 inum = inode->i_ino; 580 else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) { 581 inum = parent_ino(filp->f_dentry); 582 } else { 583 loff_t i_pos = fat_make_i_pos(sb, bh, de); 584 struct inode *tmp = fat_iget(sb, i_pos); 585 if (tmp) { 586 inum = tmp->i_ino; 587 iput(tmp); 588 } else 589 inum = iunique(sb, MSDOS_ROOT_INO); 590 } 591 592 if (isvfat) { 593 bufuname[j] = 0x0000; 594 i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname)) 595 : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io); 596 } 597 598 fill_name = bufname; 599 fill_len = i; 600 if (!short_only && long_slots) { 601 /* convert the unicode long name. 261 is maximum size 602 * of unicode buffer. (13 * slots + nul) */ 603 void *longname = unicode + 261; 604 int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0])); 605 int long_len = utf8 606 ? utf8_wcstombs(longname, unicode, buf_size) 607 : uni16_to_x8(longname, unicode, uni_xlate, nls_io); 608 609 if (!both) { 610 fill_name = longname; 611 fill_len = long_len; 612 } else { 613 /* hack for fat_ioctl_filldir() */ 614 struct fat_ioctl_filldir_callback *p = dirent; 615 616 p->longname = longname; 617 p->long_len = long_len; 618 p->shortname = bufname; 619 p->short_len = i; 620 fill_name = NULL; 621 fill_len = 0; 622 } 623 } 624 if (filldir(dirent, fill_name, fill_len, *furrfu, inum, 625 (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0) 626 goto FillFailed; 627 628 RecEnd: 629 furrfu = &lpos; 630 filp->f_pos = cpos; 631 goto GetNew; 632 EODir: 633 filp->f_pos = cpos; 634 FillFailed: 635 brelse(bh); 636 if (unicode) 637 free_page((unsigned long)unicode); 638 out: 639 unlock_kernel(); 640 return ret; 641 } 642 643 static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir) 644 { 645 struct inode *inode = filp->f_dentry->d_inode; 646 return __fat_readdir(inode, filp, dirent, filldir, 0, 0); 647 } 648 649 static int fat_ioctl_filldir(void *__buf, const char *name, int name_len, 650 loff_t offset, ino_t ino, unsigned int d_type) 651 { 652 struct fat_ioctl_filldir_callback *buf = __buf; 653 struct dirent __user *d1 = buf->dirent; 654 struct dirent __user *d2 = d1 + 1; 655 656 if (buf->result) 657 return -EINVAL; 658 buf->result++; 659 660 if (name != NULL) { 661 /* dirent has only short name */ 662 if (name_len >= sizeof(d1->d_name)) 663 name_len = sizeof(d1->d_name) - 1; 664 665 if (put_user(0, d2->d_name) || 666 put_user(0, &d2->d_reclen) || 667 copy_to_user(d1->d_name, name, name_len) || 668 put_user(0, d1->d_name + name_len) || 669 put_user(name_len, &d1->d_reclen)) 670 goto efault; 671 } else { 672 /* dirent has short and long name */ 673 const char *longname = buf->longname; 674 int long_len = buf->long_len; 675 const char *shortname = buf->shortname; 676 int short_len = buf->short_len; 677 678 if (long_len >= sizeof(d1->d_name)) 679 long_len = sizeof(d1->d_name) - 1; 680 if (short_len >= sizeof(d1->d_name)) 681 short_len = sizeof(d1->d_name) - 1; 682 683 if (copy_to_user(d2->d_name, longname, long_len) || 684 put_user(0, d2->d_name + long_len) || 685 put_user(long_len, &d2->d_reclen) || 686 put_user(ino, &d2->d_ino) || 687 put_user(offset, &d2->d_off) || 688 copy_to_user(d1->d_name, shortname, short_len) || 689 put_user(0, d1->d_name + short_len) || 690 put_user(short_len, &d1->d_reclen)) 691 goto efault; 692 } 693 return 0; 694 efault: 695 buf->result = -EFAULT; 696 return -EFAULT; 697 } 698 699 static int fat_dir_ioctl(struct inode * inode, struct file * filp, 700 unsigned int cmd, unsigned long arg) 701 { 702 struct fat_ioctl_filldir_callback buf; 703 struct dirent __user *d1; 704 int ret, short_only, both; 705 706 switch (cmd) { 707 case VFAT_IOCTL_READDIR_SHORT: 708 short_only = 1; 709 both = 0; 710 break; 711 case VFAT_IOCTL_READDIR_BOTH: 712 short_only = 0; 713 both = 1; 714 break; 715 default: 716 return fat_generic_ioctl(inode, filp, cmd, arg); 717 } 718 719 d1 = (struct dirent __user *)arg; 720 if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2]))) 721 return -EFAULT; 722 /* 723 * Yes, we don't need this put_user() absolutely. However old 724 * code didn't return the right value. So, app use this value, 725 * in order to check whether it is EOF. 726 */ 727 if (put_user(0, &d1->d_reclen)) 728 return -EFAULT; 729 730 buf.dirent = d1; 731 buf.result = 0; 732 down(&inode->i_sem); 733 ret = -ENOENT; 734 if (!IS_DEADDIR(inode)) { 735 ret = __fat_readdir(inode, filp, &buf, fat_ioctl_filldir, 736 short_only, both); 737 } 738 up(&inode->i_sem); 739 if (ret >= 0) 740 ret = buf.result; 741 return ret; 742 } 743 744 struct file_operations fat_dir_operations = { 745 .read = generic_read_dir, 746 .readdir = fat_readdir, 747 .ioctl = fat_dir_ioctl, 748 .fsync = file_fsync, 749 }; 750 751 static int fat_get_short_entry(struct inode *dir, loff_t *pos, 752 struct buffer_head **bh, 753 struct msdos_dir_entry **de) 754 { 755 while (fat_get_entry(dir, pos, bh, de) >= 0) { 756 /* free entry or long name entry or volume label */ 757 if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME)) 758 return 0; 759 } 760 return -ENOENT; 761 } 762 763 /* 764 * The ".." entry can not provide the "struct fat_slot_info" informations 765 * for inode. So, this function provide the some informations only. 766 */ 767 int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, 768 struct msdos_dir_entry **de, loff_t *i_pos) 769 { 770 loff_t offset; 771 772 offset = 0; 773 *bh = NULL; 774 while (fat_get_short_entry(dir, &offset, bh, de) >= 0) { 775 if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) { 776 *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de); 777 return 0; 778 } 779 } 780 return -ENOENT; 781 } 782 783 EXPORT_SYMBOL(fat_get_dotdot_entry); 784 785 /* See if directory is empty */ 786 int fat_dir_empty(struct inode *dir) 787 { 788 struct buffer_head *bh; 789 struct msdos_dir_entry *de; 790 loff_t cpos; 791 int result = 0; 792 793 bh = NULL; 794 cpos = 0; 795 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) { 796 if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) && 797 strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) { 798 result = -ENOTEMPTY; 799 break; 800 } 801 } 802 brelse(bh); 803 return result; 804 } 805 806 EXPORT_SYMBOL(fat_dir_empty); 807 808 /* 809 * fat_subdirs counts the number of sub-directories of dir. It can be run 810 * on directories being created. 811 */ 812 int fat_subdirs(struct inode *dir) 813 { 814 struct buffer_head *bh; 815 struct msdos_dir_entry *de; 816 loff_t cpos; 817 int count = 0; 818 819 bh = NULL; 820 cpos = 0; 821 while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) { 822 if (de->attr & ATTR_DIR) 823 count++; 824 } 825 brelse(bh); 826 return count; 827 } 828 829 /* 830 * Scans a directory for a given file (name points to its formatted name). 831 * Returns an error code or zero. 832 */ 833 int fat_scan(struct inode *dir, const unsigned char *name, 834 struct fat_slot_info *sinfo) 835 { 836 struct super_block *sb = dir->i_sb; 837 838 sinfo->slot_off = 0; 839 sinfo->bh = NULL; 840 while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh, 841 &sinfo->de) >= 0) { 842 if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) { 843 sinfo->slot_off -= sizeof(*sinfo->de); 844 sinfo->nr_slots = 1; 845 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de); 846 return 0; 847 } 848 } 849 return -ENOENT; 850 } 851 852 EXPORT_SYMBOL(fat_scan); 853 854 static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots) 855 { 856 struct super_block *sb = dir->i_sb; 857 struct buffer_head *bh; 858 struct msdos_dir_entry *de, *endp; 859 int err = 0, orig_slots; 860 861 while (nr_slots) { 862 bh = NULL; 863 if (fat_get_entry(dir, &pos, &bh, &de) < 0) { 864 err = -EIO; 865 break; 866 } 867 868 orig_slots = nr_slots; 869 endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize); 870 while (nr_slots && de < endp) { 871 de->name[0] = DELETED_FLAG; 872 de++; 873 nr_slots--; 874 } 875 mark_buffer_dirty(bh); 876 if (IS_DIRSYNC(dir)) 877 err = sync_dirty_buffer(bh); 878 brelse(bh); 879 if (err) 880 break; 881 882 /* pos is *next* de's position, so this does `- sizeof(de)' */ 883 pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de); 884 } 885 886 return err; 887 } 888 889 int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo) 890 { 891 struct msdos_dir_entry *de; 892 struct buffer_head *bh; 893 int err = 0, nr_slots; 894 895 /* 896 * First stage: Remove the shortname. By this, the directory 897 * entry is removed. 898 */ 899 nr_slots = sinfo->nr_slots; 900 de = sinfo->de; 901 sinfo->de = NULL; 902 bh = sinfo->bh; 903 sinfo->bh = NULL; 904 while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) { 905 de->name[0] = DELETED_FLAG; 906 de--; 907 nr_slots--; 908 } 909 mark_buffer_dirty(bh); 910 if (IS_DIRSYNC(dir)) 911 err = sync_dirty_buffer(bh); 912 brelse(bh); 913 if (err) 914 return err; 915 dir->i_version++; 916 917 if (nr_slots) { 918 /* 919 * Second stage: remove the remaining longname slots. 920 * (This directory entry is already removed, and so return 921 * the success) 922 */ 923 err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots); 924 if (err) { 925 printk(KERN_WARNING 926 "FAT: Couldn't remove the long name slots\n"); 927 } 928 } 929 930 dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC; 931 if (IS_DIRSYNC(dir)) 932 (void)fat_sync_inode(dir); 933 else 934 mark_inode_dirty(dir); 935 936 return 0; 937 } 938 939 EXPORT_SYMBOL(fat_remove_entries); 940 941 static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used, 942 struct buffer_head **bhs, int nr_bhs) 943 { 944 struct super_block *sb = dir->i_sb; 945 sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus; 946 int err, i, n; 947 948 /* Zeroing the unused blocks on this cluster */ 949 blknr += nr_used; 950 n = nr_used; 951 while (blknr < last_blknr) { 952 bhs[n] = sb_getblk(sb, blknr); 953 if (!bhs[n]) { 954 err = -ENOMEM; 955 goto error; 956 } 957 memset(bhs[n]->b_data, 0, sb->s_blocksize); 958 set_buffer_uptodate(bhs[n]); 959 mark_buffer_dirty(bhs[n]); 960 961 n++; 962 blknr++; 963 if (n == nr_bhs) { 964 if (IS_DIRSYNC(dir)) { 965 err = fat_sync_bhs(bhs, n); 966 if (err) 967 goto error; 968 } 969 for (i = 0; i < n; i++) 970 brelse(bhs[i]); 971 n = 0; 972 } 973 } 974 if (IS_DIRSYNC(dir)) { 975 err = fat_sync_bhs(bhs, n); 976 if (err) 977 goto error; 978 } 979 for (i = 0; i < n; i++) 980 brelse(bhs[i]); 981 982 return 0; 983 984 error: 985 for (i = 0; i < n; i++) 986 bforget(bhs[i]); 987 return err; 988 } 989 990 int fat_alloc_new_dir(struct inode *dir, struct timespec *ts) 991 { 992 struct super_block *sb = dir->i_sb; 993 struct msdos_sb_info *sbi = MSDOS_SB(sb); 994 struct buffer_head *bhs[MAX_BUF_PER_PAGE]; 995 struct msdos_dir_entry *de; 996 sector_t blknr; 997 __le16 date, time; 998 int err, cluster; 999 1000 err = fat_alloc_clusters(dir, &cluster, 1); 1001 if (err) 1002 goto error; 1003 1004 blknr = fat_clus_to_blknr(sbi, cluster); 1005 bhs[0] = sb_getblk(sb, blknr); 1006 if (!bhs[0]) { 1007 err = -ENOMEM; 1008 goto error_free; 1009 } 1010 1011 fat_date_unix2dos(ts->tv_sec, &time, &date); 1012 1013 de = (struct msdos_dir_entry *)bhs[0]->b_data; 1014 /* filling the new directory slots ("." and ".." entries) */ 1015 memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME); 1016 memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME); 1017 de->attr = de[1].attr = ATTR_DIR; 1018 de[0].lcase = de[1].lcase = 0; 1019 de[0].time = de[1].time = time; 1020 de[0].date = de[1].date = date; 1021 de[0].ctime_cs = de[1].ctime_cs = 0; 1022 if (sbi->options.isvfat) { 1023 /* extra timestamps */ 1024 de[0].ctime = de[1].ctime = time; 1025 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date; 1026 } else { 1027 de[0].ctime = de[1].ctime = 0; 1028 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0; 1029 } 1030 de[0].start = cpu_to_le16(cluster); 1031 de[0].starthi = cpu_to_le16(cluster >> 16); 1032 de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart); 1033 de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16); 1034 de[0].size = de[1].size = 0; 1035 memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de)); 1036 set_buffer_uptodate(bhs[0]); 1037 mark_buffer_dirty(bhs[0]); 1038 1039 err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE); 1040 if (err) 1041 goto error_free; 1042 1043 return cluster; 1044 1045 error_free: 1046 fat_free_clusters(dir, cluster); 1047 error: 1048 return err; 1049 } 1050 1051 EXPORT_SYMBOL(fat_alloc_new_dir); 1052 1053 static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots, 1054 int *nr_cluster, struct msdos_dir_entry **de, 1055 struct buffer_head **bh, loff_t *i_pos) 1056 { 1057 struct super_block *sb = dir->i_sb; 1058 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1059 struct buffer_head *bhs[MAX_BUF_PER_PAGE]; 1060 sector_t blknr, start_blknr, last_blknr; 1061 unsigned long size, copy; 1062 int err, i, n, offset, cluster[2]; 1063 1064 /* 1065 * The minimum cluster size is 512bytes, and maximum entry 1066 * size is 32*slots (672bytes). So, iff the cluster size is 1067 * 512bytes, we may need two clusters. 1068 */ 1069 size = nr_slots * sizeof(struct msdos_dir_entry); 1070 *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits; 1071 BUG_ON(*nr_cluster > 2); 1072 1073 err = fat_alloc_clusters(dir, cluster, *nr_cluster); 1074 if (err) 1075 goto error; 1076 1077 /* 1078 * First stage: Fill the directory entry. NOTE: This cluster 1079 * is not referenced from any inode yet, so updates order is 1080 * not important. 1081 */ 1082 i = n = copy = 0; 1083 do { 1084 start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]); 1085 last_blknr = start_blknr + sbi->sec_per_clus; 1086 while (blknr < last_blknr) { 1087 bhs[n] = sb_getblk(sb, blknr); 1088 if (!bhs[n]) { 1089 err = -ENOMEM; 1090 goto error_nomem; 1091 } 1092 1093 /* fill the directory entry */ 1094 copy = min(size, sb->s_blocksize); 1095 memcpy(bhs[n]->b_data, slots, copy); 1096 slots += copy; 1097 size -= copy; 1098 set_buffer_uptodate(bhs[n]); 1099 mark_buffer_dirty(bhs[n]); 1100 if (!size) 1101 break; 1102 n++; 1103 blknr++; 1104 } 1105 } while (++i < *nr_cluster); 1106 1107 memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy); 1108 offset = copy - sizeof(struct msdos_dir_entry); 1109 get_bh(bhs[n]); 1110 *bh = bhs[n]; 1111 *de = (struct msdos_dir_entry *)((*bh)->b_data + offset); 1112 *i_pos = fat_make_i_pos(sb, *bh, *de); 1113 1114 /* Second stage: clear the rest of cluster, and write outs */ 1115 err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE); 1116 if (err) 1117 goto error_free; 1118 1119 return cluster[0]; 1120 1121 error_free: 1122 brelse(*bh); 1123 *bh = NULL; 1124 n = 0; 1125 error_nomem: 1126 for (i = 0; i < n; i++) 1127 bforget(bhs[i]); 1128 fat_free_clusters(dir, cluster[0]); 1129 error: 1130 return err; 1131 } 1132 1133 int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 1134 struct fat_slot_info *sinfo) 1135 { 1136 struct super_block *sb = dir->i_sb; 1137 struct msdos_sb_info *sbi = MSDOS_SB(sb); 1138 struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */ 1139 struct msdos_dir_entry *de; 1140 int err, free_slots, i, nr_bhs; 1141 loff_t pos, i_pos; 1142 1143 sinfo->nr_slots = nr_slots; 1144 1145 /* First stage: search free direcotry entries */ 1146 free_slots = nr_bhs = 0; 1147 bh = prev = NULL; 1148 pos = 0; 1149 err = -ENOSPC; 1150 while (fat_get_entry(dir, &pos, &bh, &de) > -1) { 1151 /* check the maximum size of directory */ 1152 if (pos >= FAT_MAX_DIR_SIZE) 1153 goto error; 1154 1155 if (IS_FREE(de->name)) { 1156 if (prev != bh) { 1157 get_bh(bh); 1158 bhs[nr_bhs] = prev = bh; 1159 nr_bhs++; 1160 } 1161 free_slots++; 1162 if (free_slots == nr_slots) 1163 goto found; 1164 } else { 1165 for (i = 0; i < nr_bhs; i++) 1166 brelse(bhs[i]); 1167 prev = NULL; 1168 free_slots = nr_bhs = 0; 1169 } 1170 } 1171 if (dir->i_ino == MSDOS_ROOT_INO) { 1172 if (sbi->fat_bits != 32) 1173 goto error; 1174 } else if (MSDOS_I(dir)->i_start == 0) { 1175 printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n", 1176 MSDOS_I(dir)->i_pos); 1177 err = -EIO; 1178 goto error; 1179 } 1180 1181 found: 1182 err = 0; 1183 pos -= free_slots * sizeof(*de); 1184 nr_slots -= free_slots; 1185 if (free_slots) { 1186 /* 1187 * Second stage: filling the free entries with new entries. 1188 * NOTE: If this slots has shortname, first, we write 1189 * the long name slots, then write the short name. 1190 */ 1191 int size = free_slots * sizeof(*de); 1192 int offset = pos & (sb->s_blocksize - 1); 1193 int long_bhs = nr_bhs - (nr_slots == 0); 1194 1195 /* Fill the long name slots. */ 1196 for (i = 0; i < long_bhs; i++) { 1197 int copy = min_t(int, sb->s_blocksize - offset, size); 1198 memcpy(bhs[i]->b_data + offset, slots, copy); 1199 mark_buffer_dirty(bhs[i]); 1200 offset = 0; 1201 slots += copy; 1202 size -= copy; 1203 } 1204 if (long_bhs && IS_DIRSYNC(dir)) 1205 err = fat_sync_bhs(bhs, long_bhs); 1206 if (!err && i < nr_bhs) { 1207 /* Fill the short name slot. */ 1208 int copy = min_t(int, sb->s_blocksize - offset, size); 1209 memcpy(bhs[i]->b_data + offset, slots, copy); 1210 mark_buffer_dirty(bhs[i]); 1211 if (IS_DIRSYNC(dir)) 1212 err = sync_dirty_buffer(bhs[i]); 1213 } 1214 for (i = 0; i < nr_bhs; i++) 1215 brelse(bhs[i]); 1216 if (err) 1217 goto error_remove; 1218 } 1219 1220 if (nr_slots) { 1221 int cluster, nr_cluster; 1222 1223 /* 1224 * Third stage: allocate the cluster for new entries. 1225 * And initialize the cluster with new entries, then 1226 * add the cluster to dir. 1227 */ 1228 cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster, 1229 &de, &bh, &i_pos); 1230 if (cluster < 0) { 1231 err = cluster; 1232 goto error_remove; 1233 } 1234 err = fat_chain_add(dir, cluster, nr_cluster); 1235 if (err) { 1236 fat_free_clusters(dir, cluster); 1237 goto error_remove; 1238 } 1239 if (dir->i_size & (sbi->cluster_size - 1)) { 1240 fat_fs_panic(sb, "Odd directory size"); 1241 dir->i_size = (dir->i_size + sbi->cluster_size - 1) 1242 & ~((loff_t)sbi->cluster_size - 1); 1243 } 1244 dir->i_size += nr_cluster << sbi->cluster_bits; 1245 MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits; 1246 } 1247 sinfo->slot_off = pos; 1248 sinfo->de = de; 1249 sinfo->bh = bh; 1250 sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de); 1251 1252 return 0; 1253 1254 error: 1255 brelse(bh); 1256 for (i = 0; i < nr_bhs; i++) 1257 brelse(bhs[i]); 1258 return err; 1259 1260 error_remove: 1261 brelse(bh); 1262 if (free_slots) 1263 __fat_remove_entries(dir, pos, free_slots); 1264 return err; 1265 } 1266 1267 EXPORT_SYMBOL(fat_add_entries); 1268