1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/msdos/namei.c 4 * 5 * Written 1992,1993 by Werner Almesberger 6 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu> 7 * Rewritten for constant inumbers 1999 by Al Viro 8 */ 9 10 #include <linux/module.h> 11 #include <linux/iversion.h> 12 #include "fat.h" 13 14 /* Characters that are undesirable in an MS-DOS file name */ 15 static unsigned char bad_chars[] = "*?<>|\""; 16 static unsigned char bad_if_strict[] = "+=,; "; 17 18 /***** Formats an MS-DOS file name. Rejects invalid names. */ 19 static int msdos_format_name(const unsigned char *name, int len, 20 unsigned char *res, struct fat_mount_options *opts) 21 /* 22 * name is the proposed name, len is its length, res is 23 * the resulting name, opts->name_check is either (r)elaxed, 24 * (n)ormal or (s)trict, opts->dotsOK allows dots at the 25 * beginning of name (for hidden files) 26 */ 27 { 28 unsigned char *walk; 29 unsigned char c; 30 int space; 31 32 if (name[0] == '.') { /* dotfile because . and .. already done */ 33 if (opts->dotsOK) { 34 /* Get rid of dot - test for it elsewhere */ 35 name++; 36 len--; 37 } else 38 return -EINVAL; 39 } 40 /* 41 * disallow names that _really_ start with a dot 42 */ 43 space = 1; 44 c = 0; 45 for (walk = res; len && walk - res < 8; walk++) { 46 c = *name++; 47 len--; 48 if (opts->name_check != 'r' && strchr(bad_chars, c)) 49 return -EINVAL; 50 if (opts->name_check == 's' && strchr(bad_if_strict, c)) 51 return -EINVAL; 52 if (c >= 'A' && c <= 'Z' && opts->name_check == 's') 53 return -EINVAL; 54 if (c < ' ' || c == ':' || c == '\\') 55 return -EINVAL; 56 /* 57 * 0xE5 is legal as a first character, but we must substitute 58 * 0x05 because 0xE5 marks deleted files. Yes, DOS really 59 * does this. 60 * It seems that Microsoft hacked DOS to support non-US 61 * characters after the 0xE5 character was already in use to 62 * mark deleted files. 63 */ 64 if ((res == walk) && (c == 0xE5)) 65 c = 0x05; 66 if (c == '.') 67 break; 68 space = (c == ' '); 69 *walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c; 70 } 71 if (space) 72 return -EINVAL; 73 if (opts->name_check == 's' && len && c != '.') { 74 c = *name++; 75 len--; 76 if (c != '.') 77 return -EINVAL; 78 } 79 while (c != '.' && len--) 80 c = *name++; 81 if (c == '.') { 82 while (walk - res < 8) 83 *walk++ = ' '; 84 while (len > 0 && walk - res < MSDOS_NAME) { 85 c = *name++; 86 len--; 87 if (opts->name_check != 'r' && strchr(bad_chars, c)) 88 return -EINVAL; 89 if (opts->name_check == 's' && 90 strchr(bad_if_strict, c)) 91 return -EINVAL; 92 if (c < ' ' || c == ':' || c == '\\') 93 return -EINVAL; 94 if (c == '.') { 95 if (opts->name_check == 's') 96 return -EINVAL; 97 break; 98 } 99 if (c >= 'A' && c <= 'Z' && opts->name_check == 's') 100 return -EINVAL; 101 space = c == ' '; 102 if (!opts->nocase && c >= 'a' && c <= 'z') 103 *walk++ = c - 32; 104 else 105 *walk++ = c; 106 } 107 if (space) 108 return -EINVAL; 109 if (opts->name_check == 's' && len) 110 return -EINVAL; 111 } 112 while (walk - res < MSDOS_NAME) 113 *walk++ = ' '; 114 115 return 0; 116 } 117 118 /***** Locates a directory entry. Uses unformatted name. */ 119 static int msdos_find(struct inode *dir, const unsigned char *name, int len, 120 struct fat_slot_info *sinfo) 121 { 122 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); 123 unsigned char msdos_name[MSDOS_NAME]; 124 int err; 125 126 err = msdos_format_name(name, len, msdos_name, &sbi->options); 127 if (err) 128 return -ENOENT; 129 130 err = fat_scan(dir, msdos_name, sinfo); 131 if (!err && sbi->options.dotsOK) { 132 if (name[0] == '.') { 133 if (!(sinfo->de->attr & ATTR_HIDDEN)) 134 err = -ENOENT; 135 } else { 136 if (sinfo->de->attr & ATTR_HIDDEN) 137 err = -ENOENT; 138 } 139 if (err) 140 brelse(sinfo->bh); 141 } 142 return err; 143 } 144 145 /* 146 * Compute the hash for the msdos name corresponding to the dentry. 147 * Note: if the name is invalid, we leave the hash code unchanged so 148 * that the existing dentry can be used. The msdos fs routines will 149 * return ENOENT or EINVAL as appropriate. 150 */ 151 static int msdos_hash(const struct dentry *dentry, struct qstr *qstr) 152 { 153 struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options; 154 unsigned char msdos_name[MSDOS_NAME]; 155 int error; 156 157 error = msdos_format_name(qstr->name, qstr->len, msdos_name, options); 158 if (!error) 159 qstr->hash = full_name_hash(dentry, msdos_name, MSDOS_NAME); 160 return 0; 161 } 162 163 /* 164 * Compare two msdos names. If either of the names are invalid, 165 * we fall back to doing the standard name comparison. 166 */ 167 static int msdos_cmp(const struct dentry *dentry, 168 unsigned int len, const char *str, const struct qstr *name) 169 { 170 struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options; 171 unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME]; 172 int error; 173 174 error = msdos_format_name(name->name, name->len, a_msdos_name, options); 175 if (error) 176 goto old_compare; 177 error = msdos_format_name(str, len, b_msdos_name, options); 178 if (error) 179 goto old_compare; 180 error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME); 181 out: 182 return error; 183 184 old_compare: 185 error = 1; 186 if (name->len == len) 187 error = memcmp(name->name, str, len); 188 goto out; 189 } 190 191 static const struct dentry_operations msdos_dentry_operations = { 192 .d_hash = msdos_hash, 193 .d_compare = msdos_cmp, 194 }; 195 196 /* 197 * AV. Wrappers for FAT sb operations. Is it wise? 198 */ 199 200 /***** Get inode using directory and name */ 201 static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry, 202 unsigned int flags) 203 { 204 struct super_block *sb = dir->i_sb; 205 struct fat_slot_info sinfo; 206 struct inode *inode; 207 int err; 208 209 mutex_lock(&MSDOS_SB(sb)->s_lock); 210 err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo); 211 switch (err) { 212 case -ENOENT: 213 inode = NULL; 214 break; 215 case 0: 216 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); 217 brelse(sinfo.bh); 218 break; 219 default: 220 inode = ERR_PTR(err); 221 } 222 mutex_unlock(&MSDOS_SB(sb)->s_lock); 223 return d_splice_alias(inode, dentry); 224 } 225 226 /***** Creates a directory entry (name is already formatted). */ 227 static int msdos_add_entry(struct inode *dir, const unsigned char *name, 228 int is_dir, int is_hid, int cluster, 229 struct timespec64 *ts, struct fat_slot_info *sinfo) 230 { 231 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); 232 struct msdos_dir_entry de; 233 __le16 time, date; 234 int err; 235 236 memcpy(de.name, name, MSDOS_NAME); 237 de.attr = is_dir ? ATTR_DIR : ATTR_ARCH; 238 if (is_hid) 239 de.attr |= ATTR_HIDDEN; 240 de.lcase = 0; 241 fat_time_unix2fat(sbi, ts, &time, &date, NULL); 242 de.cdate = de.adate = 0; 243 de.ctime = 0; 244 de.ctime_cs = 0; 245 de.time = time; 246 de.date = date; 247 fat_set_start(&de, cluster); 248 de.size = 0; 249 250 err = fat_add_entries(dir, &de, 1, sinfo); 251 if (err) 252 return err; 253 254 fat_truncate_time(dir, ts, S_CTIME|S_MTIME); 255 if (IS_DIRSYNC(dir)) 256 (void)fat_sync_inode(dir); 257 else 258 mark_inode_dirty(dir); 259 260 return 0; 261 } 262 263 /***** Create a file */ 264 static int msdos_create(struct mnt_idmap *idmap, struct inode *dir, 265 struct dentry *dentry, umode_t mode, bool excl) 266 { 267 struct super_block *sb = dir->i_sb; 268 struct inode *inode = NULL; 269 struct fat_slot_info sinfo; 270 struct timespec64 ts; 271 unsigned char msdos_name[MSDOS_NAME]; 272 int err, is_hid; 273 274 mutex_lock(&MSDOS_SB(sb)->s_lock); 275 276 err = msdos_format_name(dentry->d_name.name, dentry->d_name.len, 277 msdos_name, &MSDOS_SB(sb)->options); 278 if (err) 279 goto out; 280 is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.'); 281 /* Have to do it due to foo vs. .foo conflicts */ 282 if (!fat_scan(dir, msdos_name, &sinfo)) { 283 brelse(sinfo.bh); 284 err = -EINVAL; 285 goto out; 286 } 287 288 ts = current_time(dir); 289 err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo); 290 if (err) 291 goto out; 292 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); 293 brelse(sinfo.bh); 294 if (IS_ERR(inode)) { 295 err = PTR_ERR(inode); 296 goto out; 297 } 298 fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME); 299 /* timestamp is already written, so mark_inode_dirty() is unneeded. */ 300 301 d_instantiate(dentry, inode); 302 out: 303 mutex_unlock(&MSDOS_SB(sb)->s_lock); 304 if (!err) 305 err = fat_flush_inodes(sb, dir, inode); 306 return err; 307 } 308 309 /***** Remove a directory */ 310 static int msdos_rmdir(struct inode *dir, struct dentry *dentry) 311 { 312 struct super_block *sb = dir->i_sb; 313 struct inode *inode = d_inode(dentry); 314 struct fat_slot_info sinfo; 315 int err; 316 317 mutex_lock(&MSDOS_SB(sb)->s_lock); 318 err = fat_dir_empty(inode); 319 if (err) 320 goto out; 321 err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo); 322 if (err) 323 goto out; 324 325 err = fat_remove_entries(dir, &sinfo); /* and releases bh */ 326 if (err) 327 goto out; 328 if (dir->i_nlink >= 3) 329 drop_nlink(dir); 330 else { 331 fat_fs_error(sb, "parent dir link count too low (%u)", 332 dir->i_nlink); 333 } 334 335 clear_nlink(inode); 336 fat_truncate_time(inode, NULL, S_CTIME); 337 fat_detach(inode); 338 out: 339 mutex_unlock(&MSDOS_SB(sb)->s_lock); 340 if (!err) 341 err = fat_flush_inodes(sb, dir, inode); 342 343 return err; 344 } 345 346 /***** Make a directory */ 347 static struct dentry *msdos_mkdir(struct mnt_idmap *idmap, struct inode *dir, 348 struct dentry *dentry, umode_t mode) 349 { 350 struct super_block *sb = dir->i_sb; 351 struct fat_slot_info sinfo; 352 struct inode *inode; 353 unsigned char msdos_name[MSDOS_NAME]; 354 struct timespec64 ts; 355 int err, is_hid, cluster; 356 357 mutex_lock(&MSDOS_SB(sb)->s_lock); 358 359 err = msdos_format_name(dentry->d_name.name, dentry->d_name.len, 360 msdos_name, &MSDOS_SB(sb)->options); 361 if (err) 362 goto out; 363 is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.'); 364 /* foo vs .foo situation */ 365 if (!fat_scan(dir, msdos_name, &sinfo)) { 366 brelse(sinfo.bh); 367 err = -EINVAL; 368 goto out; 369 } 370 371 ts = current_time(dir); 372 cluster = fat_alloc_new_dir(dir, &ts); 373 if (cluster < 0) { 374 err = cluster; 375 goto out; 376 } 377 err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo); 378 if (err) 379 goto out_free; 380 inc_nlink(dir); 381 382 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); 383 brelse(sinfo.bh); 384 if (IS_ERR(inode)) { 385 err = PTR_ERR(inode); 386 /* the directory was completed, just return a error */ 387 goto out; 388 } 389 set_nlink(inode, 2); 390 fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME); 391 /* timestamp is already written, so mark_inode_dirty() is unneeded. */ 392 393 d_instantiate(dentry, inode); 394 395 mutex_unlock(&MSDOS_SB(sb)->s_lock); 396 fat_flush_inodes(sb, dir, inode); 397 return NULL; 398 399 out_free: 400 fat_free_clusters(dir, cluster); 401 out: 402 mutex_unlock(&MSDOS_SB(sb)->s_lock); 403 return ERR_PTR(err); 404 } 405 406 /***** Unlink a file */ 407 static int msdos_unlink(struct inode *dir, struct dentry *dentry) 408 { 409 struct inode *inode = d_inode(dentry); 410 struct super_block *sb = inode->i_sb; 411 struct fat_slot_info sinfo; 412 int err; 413 414 mutex_lock(&MSDOS_SB(sb)->s_lock); 415 err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo); 416 if (err) 417 goto out; 418 419 err = fat_remove_entries(dir, &sinfo); /* and releases bh */ 420 if (err) 421 goto out; 422 clear_nlink(inode); 423 fat_truncate_time(inode, NULL, S_CTIME); 424 fat_detach(inode); 425 out: 426 mutex_unlock(&MSDOS_SB(sb)->s_lock); 427 if (!err) 428 err = fat_flush_inodes(sb, dir, inode); 429 430 return err; 431 } 432 433 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name, 434 struct dentry *old_dentry, 435 struct inode *new_dir, unsigned char *new_name, 436 struct dentry *new_dentry, int is_hid) 437 { 438 struct buffer_head *dotdot_bh; 439 struct msdos_dir_entry *dotdot_de; 440 struct inode *old_inode, *new_inode; 441 struct fat_slot_info old_sinfo, sinfo; 442 struct timespec64 ts; 443 loff_t new_i_pos; 444 int err, old_attrs, is_dir, update_dotdot, corrupt = 0; 445 446 old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; 447 old_inode = d_inode(old_dentry); 448 new_inode = d_inode(new_dentry); 449 450 err = fat_scan(old_dir, old_name, &old_sinfo); 451 if (err) { 452 err = -EIO; 453 goto out; 454 } 455 456 is_dir = S_ISDIR(old_inode->i_mode); 457 update_dotdot = (is_dir && old_dir != new_dir); 458 if (update_dotdot) { 459 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) { 460 err = -EIO; 461 goto out; 462 } 463 } 464 465 old_attrs = MSDOS_I(old_inode)->i_attrs; 466 err = fat_scan(new_dir, new_name, &sinfo); 467 if (!err) { 468 if (!new_inode) { 469 /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */ 470 if (sinfo.de != old_sinfo.de) { 471 err = -EINVAL; 472 goto out; 473 } 474 if (is_hid) 475 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN; 476 else 477 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN; 478 if (IS_DIRSYNC(old_dir)) { 479 err = fat_sync_inode(old_inode); 480 if (err) { 481 MSDOS_I(old_inode)->i_attrs = old_attrs; 482 goto out; 483 } 484 } else 485 mark_inode_dirty(old_inode); 486 487 inode_inc_iversion(old_dir); 488 fat_truncate_time(old_dir, NULL, S_CTIME|S_MTIME); 489 if (IS_DIRSYNC(old_dir)) 490 (void)fat_sync_inode(old_dir); 491 else 492 mark_inode_dirty(old_dir); 493 goto out; 494 } 495 } 496 497 ts = current_time(old_inode); 498 if (new_inode) { 499 if (err) 500 goto out; 501 if (is_dir) { 502 err = fat_dir_empty(new_inode); 503 if (err) 504 goto out; 505 } 506 new_i_pos = MSDOS_I(new_inode)->i_pos; 507 fat_detach(new_inode); 508 } else { 509 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0, 510 &ts, &sinfo); 511 if (err) 512 goto out; 513 new_i_pos = sinfo.i_pos; 514 } 515 inode_inc_iversion(new_dir); 516 517 fat_detach(old_inode); 518 fat_attach(old_inode, new_i_pos); 519 if (is_hid) 520 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN; 521 else 522 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN; 523 if (IS_DIRSYNC(new_dir)) { 524 err = fat_sync_inode(old_inode); 525 if (err) 526 goto error_inode; 527 } else 528 mark_inode_dirty(old_inode); 529 530 if (update_dotdot) { 531 fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart); 532 mark_buffer_dirty_inode(dotdot_bh, old_inode); 533 if (IS_DIRSYNC(new_dir)) { 534 err = sync_dirty_buffer(dotdot_bh); 535 if (err) 536 goto error_dotdot; 537 } 538 drop_nlink(old_dir); 539 if (!new_inode) 540 inc_nlink(new_dir); 541 } 542 543 err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ 544 old_sinfo.bh = NULL; 545 if (err) 546 goto error_dotdot; 547 inode_inc_iversion(old_dir); 548 fat_truncate_time(old_dir, &ts, S_CTIME|S_MTIME); 549 if (IS_DIRSYNC(old_dir)) 550 (void)fat_sync_inode(old_dir); 551 else 552 mark_inode_dirty(old_dir); 553 554 if (new_inode) { 555 drop_nlink(new_inode); 556 if (is_dir) 557 drop_nlink(new_inode); 558 fat_truncate_time(new_inode, &ts, S_CTIME); 559 } 560 out: 561 brelse(sinfo.bh); 562 brelse(dotdot_bh); 563 brelse(old_sinfo.bh); 564 return err; 565 566 error_dotdot: 567 /* data cluster is shared, serious corruption */ 568 corrupt = 1; 569 570 if (update_dotdot) { 571 fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart); 572 mark_buffer_dirty_inode(dotdot_bh, old_inode); 573 corrupt |= sync_dirty_buffer(dotdot_bh); 574 } 575 error_inode: 576 fat_detach(old_inode); 577 fat_attach(old_inode, old_sinfo.i_pos); 578 MSDOS_I(old_inode)->i_attrs = old_attrs; 579 if (new_inode) { 580 fat_attach(new_inode, new_i_pos); 581 if (corrupt) 582 corrupt |= fat_sync_inode(new_inode); 583 } else { 584 /* 585 * If new entry was not sharing the data cluster, it 586 * shouldn't be serious corruption. 587 */ 588 int err2 = fat_remove_entries(new_dir, &sinfo); 589 if (corrupt) 590 corrupt |= err2; 591 sinfo.bh = NULL; 592 } 593 if (corrupt < 0) { 594 fat_fs_error(new_dir->i_sb, 595 "%s: Filesystem corrupted (i_pos %lld)", 596 __func__, sinfo.i_pos); 597 } 598 goto out; 599 } 600 601 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */ 602 static int msdos_rename(struct mnt_idmap *idmap, 603 struct inode *old_dir, struct dentry *old_dentry, 604 struct inode *new_dir, struct dentry *new_dentry, 605 unsigned int flags) 606 { 607 struct super_block *sb = old_dir->i_sb; 608 unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME]; 609 int err, is_hid; 610 611 if (flags & ~RENAME_NOREPLACE) 612 return -EINVAL; 613 614 mutex_lock(&MSDOS_SB(sb)->s_lock); 615 616 err = msdos_format_name(old_dentry->d_name.name, 617 old_dentry->d_name.len, old_msdos_name, 618 &MSDOS_SB(old_dir->i_sb)->options); 619 if (err) 620 goto out; 621 err = msdos_format_name(new_dentry->d_name.name, 622 new_dentry->d_name.len, new_msdos_name, 623 &MSDOS_SB(new_dir->i_sb)->options); 624 if (err) 625 goto out; 626 627 is_hid = 628 (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.'); 629 630 err = do_msdos_rename(old_dir, old_msdos_name, old_dentry, 631 new_dir, new_msdos_name, new_dentry, is_hid); 632 out: 633 mutex_unlock(&MSDOS_SB(sb)->s_lock); 634 if (!err) 635 err = fat_flush_inodes(sb, old_dir, new_dir); 636 return err; 637 } 638 639 static const struct inode_operations msdos_dir_inode_operations = { 640 .create = msdos_create, 641 .lookup = msdos_lookup, 642 .unlink = msdos_unlink, 643 .mkdir = msdos_mkdir, 644 .rmdir = msdos_rmdir, 645 .rename = msdos_rename, 646 .setattr = fat_setattr, 647 .getattr = fat_getattr, 648 .update_time = fat_update_time, 649 }; 650 651 static void setup(struct super_block *sb) 652 { 653 MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations; 654 set_default_d_op(sb, &msdos_dentry_operations); 655 sb->s_flags |= SB_NOATIME; 656 } 657 658 static int msdos_fill_super(struct super_block *sb, struct fs_context *fc) 659 { 660 return fat_fill_super(sb, fc, setup); 661 } 662 663 static int msdos_get_tree(struct fs_context *fc) 664 { 665 return get_tree_bdev(fc, msdos_fill_super); 666 } 667 668 static int msdos_parse_param(struct fs_context *fc, struct fs_parameter *param) 669 { 670 return fat_parse_param(fc, param, false); 671 } 672 673 static const struct fs_context_operations msdos_context_ops = { 674 .parse_param = msdos_parse_param, 675 .get_tree = msdos_get_tree, 676 .reconfigure = fat_reconfigure, 677 .free = fat_free_fc, 678 }; 679 680 static int msdos_init_fs_context(struct fs_context *fc) 681 { 682 int err; 683 684 /* Initialize with is_vfat == false */ 685 err = fat_init_fs_context(fc, false); 686 if (err) 687 return err; 688 689 fc->ops = &msdos_context_ops; 690 return 0; 691 } 692 693 static struct file_system_type msdos_fs_type = { 694 .owner = THIS_MODULE, 695 .name = "msdos", 696 .kill_sb = kill_block_super, 697 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 698 .init_fs_context = msdos_init_fs_context, 699 .parameters = fat_param_spec, 700 }; 701 MODULE_ALIAS_FS("msdos"); 702 703 static int __init init_msdos_fs(void) 704 { 705 return register_filesystem(&msdos_fs_type); 706 } 707 708 static void __exit exit_msdos_fs(void) 709 { 710 unregister_filesystem(&msdos_fs_type); 711 } 712 713 MODULE_LICENSE("GPL"); 714 MODULE_AUTHOR("Werner Almesberger"); 715 MODULE_DESCRIPTION("MS-DOS filesystem support"); 716 717 module_init(init_msdos_fs) 718 module_exit(exit_msdos_fs) 719