fs/fat/namei_msdos.c

   1 /*
   2  *  linux/fs/msdos/namei.c
   3  *
   4  *  Written 1992,1993 by Werner Almesberger
   5  *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
   6  *  Rewritten for constant inumbers 1999 by Al Viro
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/time.h>
  11 #include <linux/buffer_head.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, const struct inode *inode,
 152                struct qstr *qstr)
 153 {
 154         struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 155         unsigned char msdos_name[MSDOS_NAME];
 156         int error;
 157
 158         error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
 159         if (!error)
 160                 qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
 161         return 0;
 162 }
 163
 164 /*
 165  * Compare two msdos names. If either of the names are invalid,
 166  * we fall back to doing the standard name comparison.
 167  */
 168 static int msdos_cmp(const struct dentry *parent, const struct inode *pinode,
 169                 const struct dentry *dentry, const struct inode *inode,
 170                 unsigned int len, const char *str, const struct qstr *name)
 171 {
 172         struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
 173         unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 174         int error;
 175
 176         error = msdos_format_name(name->name, name->len, a_msdos_name, options);
 177         if (error)
 178                 goto old_compare;
 179         error = msdos_format_name(str, len, b_msdos_name, options);
 180         if (error)
 181                 goto old_compare;
 182         error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
 183 out:
 184         return error;
 185
 186 old_compare:
 187         error = 1;
 188         if (name->len == len)
 189                 error = memcmp(name->name, str, len);
 190         goto out;
 191 }
 192
 193 static const struct dentry_operations msdos_dentry_operations = {
 194         .d_hash         = msdos_hash,
 195         .d_compare      = msdos_cmp,
 196 };
 197
 198 /*
 199  * AV. Wrappers for FAT sb operations. Is it wise?
 200  */
 201
 202 /***** Get inode using directory and name */
 203 static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
 204                                    unsigned int flags)
 205 {
 206         struct super_block *sb = dir->i_sb;
 207         struct fat_slot_info sinfo;
 208         struct inode *inode;
 209         int err;
 210
 211         lock_super(sb);
 212         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 213         switch (err) {
 214         case -ENOENT:
 215                 inode = NULL;
 216                 break;
 217         case 0:
 218                 inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 219                 brelse(sinfo.bh);
 220                 break;
 221         default:
 222                 inode = ERR_PTR(err);
 223         }
 224         unlock_super(sb);
 225         return d_splice_alias(inode, dentry);
 226 }
 227
 228 /***** Creates a directory entry (name is already formatted). */
 229 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 230                            int is_dir, int is_hid, int cluster,
 231                            struct timespec *ts, struct fat_slot_info *sinfo)
 232 {
 233         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 234         struct msdos_dir_entry de;
 235         __le16 time, date;
 236         int err;
 237
 238         memcpy(de.name, name, MSDOS_NAME);
 239         de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 240         if (is_hid)
 241                 de.attr |= ATTR_HIDDEN;
 242         de.lcase = 0;
 243         fat_time_unix2fat(sbi, ts, &time, &date, NULL);
 244         de.cdate = de.adate = 0;
 245         de.ctime = 0;
 246         de.ctime_cs = 0;
 247         de.time = time;
 248         de.date = date;
 249         fat_set_start(&de, cluster);
 250         de.size = 0;
 251
 252         err = fat_add_entries(dir, &de, 1, sinfo);
 253         if (err)
 254                 return err;
 255
 256         dir->i_ctime = dir->i_mtime = *ts;
 257         if (IS_DIRSYNC(dir))
 258                 (void)fat_sync_inode(dir);
 259         else
 260                 mark_inode_dirty(dir);
 261
 262         return 0;
 263 }
 264
 265 /***** Create a file */
 266 static int msdos_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 267                         bool excl)
 268 {
 269         struct super_block *sb = dir->i_sb;
 270         struct inode *inode = NULL;
 271         struct fat_slot_info sinfo;
 272         struct timespec ts;
 273         unsigned char msdos_name[MSDOS_NAME];
 274         int err, is_hid;
 275
 276         lock_super(sb);
 277
 278         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 279                                 msdos_name, &MSDOS_SB(sb)->options);
 280         if (err)
 281                 goto out;
 282         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 283         /* Have to do it due to foo vs. .foo conflicts */
 284         if (!fat_scan(dir, msdos_name, &sinfo)) {
 285                 brelse(sinfo.bh);
 286                 err = -EINVAL;
 287                 goto out;
 288         }
 289
 290         ts = CURRENT_TIME_SEC;
 291         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 292         if (err)
 293                 goto out;
 294         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 295         brelse(sinfo.bh);
 296         if (IS_ERR(inode)) {
 297                 err = PTR_ERR(inode);
 298                 goto out;
 299         }
 300         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 301         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 302
 303         d_instantiate(dentry, inode);
 304 out:
 305         unlock_super(sb);
 306         if (!err)
 307                 err = fat_flush_inodes(sb, dir, inode);
 308         return err;
 309 }
 310
 311 /***** Remove a directory */
 312 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 313 {
 314         struct super_block *sb = dir->i_sb;
 315         struct inode *inode = dentry->d_inode;
 316         struct fat_slot_info sinfo;
 317         int err;
 318
 319         lock_super(sb);
 320         /*
 321          * Check whether the directory is not in use, then check
 322          * whether it is empty.
 323          */
 324         err = fat_dir_empty(inode);
 325         if (err)
 326                 goto out;
 327         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 328         if (err)
 329                 goto out;
 330
 331         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 332         if (err)
 333                 goto out;
 334         drop_nlink(dir);
 335
 336         clear_nlink(inode);
 337         inode->i_ctime = CURRENT_TIME_SEC;
 338         fat_detach(inode);
 339 out:
 340         unlock_super(sb);
 341         if (!err)
 342                 err = fat_flush_inodes(sb, dir, inode);
 343
 344         return err;
 345 }
 346
 347 /***** Make a directory */
 348 static int msdos_mkdir(struct inode *dir, 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 timespec ts;
 355         int err, is_hid, cluster;
 356
 357         lock_super(sb);
 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_SEC;
 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         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 391         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 392
 393         d_instantiate(dentry, inode);
 394
 395         unlock_super(sb);
 396         fat_flush_inodes(sb, dir, inode);
 397         return 0;
 398
 399 out_free:
 400         fat_free_clusters(dir, cluster);
 401 out:
 402         unlock_super(sb);
 403         return err;
 404 }
 405
 406 /***** Unlink a file */
 407 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 408 {
 409         struct inode *inode = dentry->d_inode;
 410         struct super_block *sb= inode->i_sb;
 411         struct fat_slot_info sinfo;
 412         int err;
 413
 414         lock_super(sb);
 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         inode->i_ctime = CURRENT_TIME_SEC;
 424         fat_detach(inode);
 425 out:
 426         unlock_super(sb);
 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 timespec ts;
 443         loff_t dotdot_i_pos, 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 = old_dentry->d_inode;
 448         new_inode = new_dentry->d_inode;
 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                                          &dotdot_i_pos) < 0) {
 461                         err = -EIO;
 462                         goto out;
 463                 }
 464         }
 465
 466         old_attrs = MSDOS_I(old_inode)->i_attrs;
 467         err = fat_scan(new_dir, new_name, &sinfo);
 468         if (!err) {
 469                 if (!new_inode) {
 470                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 471                         if (sinfo.de != old_sinfo.de) {
 472                                 err = -EINVAL;
 473                                 goto out;
 474                         }
 475                         if (is_hid)
 476                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 477                         else
 478                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 479                         if (IS_DIRSYNC(old_dir)) {
 480                                 err = fat_sync_inode(old_inode);
 481                                 if (err) {
 482                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 483                                         goto out;
 484                                 }
 485                         } else
 486                                 mark_inode_dirty(old_inode);
 487
 488                         old_dir->i_version++;
 489                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 490                         if (IS_DIRSYNC(old_dir))
 491                                 (void)fat_sync_inode(old_dir);
 492                         else
 493                                 mark_inode_dirty(old_dir);
 494                         goto out;
 495                 }
 496         }
 497
 498         ts = CURRENT_TIME_SEC;
 499         if (new_inode) {
 500                 if (err)
 501                         goto out;
 502                 if (is_dir) {
 503                         err = fat_dir_empty(new_inode);
 504                         if (err)
 505                                 goto out;
 506                 }
 507                 new_i_pos = MSDOS_I(new_inode)->i_pos;
 508                 fat_detach(new_inode);
 509         } else {
 510                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 511                                       &ts, &sinfo);
 512                 if (err)
 513                         goto out;
 514                 new_i_pos = sinfo.i_pos;
 515         }
 516         new_dir->i_version++;
 517
 518         fat_detach(old_inode);
 519         fat_attach(old_inode, new_i_pos);
 520         if (is_hid)
 521                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 522         else
 523                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 524         if (IS_DIRSYNC(new_dir)) {
 525                 err = fat_sync_inode(old_inode);
 526                 if (err)
 527                         goto error_inode;
 528         } else
 529                 mark_inode_dirty(old_inode);
 530
 531         if (update_dotdot) {
 532                 fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
 533                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 534                 if (IS_DIRSYNC(new_dir)) {
 535                         err = sync_dirty_buffer(dotdot_bh);
 536                         if (err)
 537                                 goto error_dotdot;
 538                 }
 539                 drop_nlink(old_dir);
 540                 if (!new_inode)
 541                         inc_nlink(new_dir);
 542         }
 543
 544         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 545         old_sinfo.bh = NULL;
 546         if (err)
 547                 goto error_dotdot;
 548         old_dir->i_version++;
 549         old_dir->i_ctime = old_dir->i_mtime = ts;
 550         if (IS_DIRSYNC(old_dir))
 551                 (void)fat_sync_inode(old_dir);
 552         else
 553                 mark_inode_dirty(old_dir);
 554
 555         if (new_inode) {
 556                 drop_nlink(new_inode);
 557                 if (is_dir)
 558                         drop_nlink(new_inode);
 559                 new_inode->i_ctime = ts;
 560         }
 561 out:
 562         brelse(sinfo.bh);
 563         brelse(dotdot_bh);
 564         brelse(old_sinfo.bh);
 565         return err;
 566
 567 error_dotdot:
 568         /* data cluster is shared, serious corruption */
 569         corrupt = 1;
 570
 571         if (update_dotdot) {
 572                 fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
 573                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 574                 corrupt |= sync_dirty_buffer(dotdot_bh);
 575         }
 576 error_inode:
 577         fat_detach(old_inode);
 578         fat_attach(old_inode, old_sinfo.i_pos);
 579         MSDOS_I(old_inode)->i_attrs = old_attrs;
 580         if (new_inode) {
 581                 fat_attach(new_inode, new_i_pos);
 582                 if (corrupt)
 583                         corrupt |= fat_sync_inode(new_inode);
 584         } else {
 585                 /*
 586                  * If new entry was not sharing the data cluster, it
 587                  * shouldn't be serious corruption.
 588                  */
 589                 int err2 = fat_remove_entries(new_dir, &sinfo);
 590                 if (corrupt)
 591                         corrupt |= err2;
 592                 sinfo.bh = NULL;
 593         }
 594         if (corrupt < 0) {
 595                 fat_fs_error(new_dir->i_sb,
 596                              "%s: Filesystem corrupted (i_pos %lld)",
 597                              __func__, sinfo.i_pos);
 598         }
 599         goto out;
 600 }
 601
 602 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 603 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 604                         struct inode *new_dir, struct dentry *new_dentry)
 605 {
 606         struct super_block *sb = old_dir->i_sb;
 607         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 608         int err, is_hid;
 609
 610         lock_super(sb);
 611
 612         err = msdos_format_name(old_dentry->d_name.name,
 613                                 old_dentry->d_name.len, old_msdos_name,
 614                                 &MSDOS_SB(old_dir->i_sb)->options);
 615         if (err)
 616                 goto out;
 617         err = msdos_format_name(new_dentry->d_name.name,
 618                                 new_dentry->d_name.len, new_msdos_name,
 619                                 &MSDOS_SB(new_dir->i_sb)->options);
 620         if (err)
 621                 goto out;
 622
 623         is_hid =
 624              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 625
 626         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 627                               new_dir, new_msdos_name, new_dentry, is_hid);
 628 out:
 629         unlock_super(sb);
 630         if (!err)
 631                 err = fat_flush_inodes(sb, old_dir, new_dir);
 632         return err;
 633 }
 634
 635 static const struct inode_operations msdos_dir_inode_operations = {
 636         .create         = msdos_create,
 637         .lookup         = msdos_lookup,
 638         .unlink         = msdos_unlink,
 639         .mkdir          = msdos_mkdir,
 640         .rmdir          = msdos_rmdir,
 641         .rename         = msdos_rename,
 642         .setattr        = fat_setattr,
 643         .getattr        = fat_getattr,
 644 };
 645
 646 static void setup(struct super_block *sb)
 647 {
 648         MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
 649         sb->s_d_op = &msdos_dentry_operations;
 650         sb->s_flags |= MS_NOATIME;
 651 }
 652
 653 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 654 {
 655         return fat_fill_super(sb, data, silent, 0, setup);
 656 }
 657
 658 static struct dentry *msdos_mount(struct file_system_type *fs_type,
 659                         int flags, const char *dev_name,
 660                         void *data)
 661 {
 662         return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
 663 }
 664
 665 static struct file_system_type msdos_fs_type = {
 666         .owner          = THIS_MODULE,
 667         .name           = "msdos",
 668         .mount          = msdos_mount,
 669         .kill_sb        = kill_block_super,
 670         .fs_flags       = FS_REQUIRES_DEV,
 671 };
 672
 673 static int __init init_msdos_fs(void)
 674 {
 675         return register_filesystem(&msdos_fs_type);
 676 }
 677
 678 static void __exit exit_msdos_fs(void)
 679 {
 680         unregister_filesystem(&msdos_fs_type);
 681 }
 682
 683 MODULE_LICENSE("GPL");
 684 MODULE_AUTHOR("Werner Almesberger");
 685 MODULE_DESCRIPTION("MS-DOS filesystem support");
 686
 687 module_init(init_msdos_fs)
 688 module_exit(exit_msdos_fs)