fs/msdos/namei.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 <linux/msdos_fs.h>
  13 #include <linux/smp_lock.h>
  14
  15 /* Characters that are undesirable in an MS-DOS file name */
  16 static unsigned char bad_chars[] = "*?<>|\"";
  17 static unsigned char bad_if_strict[] = "+=,; ";
  18
  19 /***** Formats an MS-DOS file name. Rejects invalid names. */
  20 static int msdos_format_name(const unsigned char *name, int len,
  21                              unsigned char *res, struct fat_mount_options *opts)
  22         /*
  23          * name is the proposed name, len is its length, res is
  24          * the resulting name, opts->name_check is either (r)elaxed,
  25          * (n)ormal or (s)trict, opts->dotsOK allows dots at the
  26          * beginning of name (for hidden files)
  27          */
  28 {
  29         unsigned char *walk;
  30         unsigned char c;
  31         int space;
  32
  33         if (name[0] == '.') {   /* dotfile because . and .. already done */
  34                 if (opts->dotsOK) {
  35                         /* Get rid of dot - test for it elsewhere */
  36                         name++;
  37                         len--;
  38                 } else
  39                         return -EINVAL;
  40         }
  41         /*
  42          * disallow names that _really_ start with a dot
  43          */
  44         space = 1;
  45         c = 0;
  46         for (walk = res; len && walk - res < 8; walk++) {
  47                 c = *name++;
  48                 len--;
  49                 if (opts->name_check != 'r' && strchr(bad_chars, c))
  50                         return -EINVAL;
  51                 if (opts->name_check == 's' && strchr(bad_if_strict, c))
  52                         return -EINVAL;
  53                 if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
  54                         return -EINVAL;
  55                 if (c < ' ' || c == ':' || c == '\\')
  56                         return -EINVAL;
  57         /*
  58          * 0xE5 is legal as a first character, but we must substitute
  59          * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
  60          * does this.
  61          * It seems that Microsoft hacked DOS to support non-US
  62          * characters after the 0xE5 character was already in use to
  63          * mark deleted files.
  64          */
  65                 if ((res == walk) && (c == 0xE5))
  66                         c = 0x05;
  67                 if (c == '.')
  68                         break;
  69                 space = (c == ' ');
  70                 *walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
  71         }
  72         if (space)
  73                 return -EINVAL;
  74         if (opts->name_check == 's' && len && c != '.') {
  75                 c = *name++;
  76                 len--;
  77                 if (c != '.')
  78                         return -EINVAL;
  79         }
  80         while (c != '.' && len--)
  81                 c = *name++;
  82         if (c == '.') {
  83                 while (walk - res < 8)
  84                         *walk++ = ' ';
  85                 while (len > 0 && walk - res < MSDOS_NAME) {
  86                         c = *name++;
  87                         len--;
  88                         if (opts->name_check != 'r' && strchr(bad_chars, c))
  89                                 return -EINVAL;
  90                         if (opts->name_check == 's' &&
  91                             strchr(bad_if_strict, c))
  92                                 return -EINVAL;
  93                         if (c < ' ' || c == ':' || c == '\\')
  94                                 return -EINVAL;
  95                         if (c == '.') {
  96                                 if (opts->name_check == 's')
  97                                         return -EINVAL;
  98                                 break;
  99                         }
 100                         if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
 101                                 return -EINVAL;
 102                         space = c == ' ';
 103                         if (!opts->nocase && c >= 'a' && c <= 'z')
 104                                 *walk++ = c - 32;
 105                         else
 106                                 *walk++ = c;
 107                 }
 108                 if (space)
 109                         return -EINVAL;
 110                 if (opts->name_check == 's' && len)
 111                         return -EINVAL;
 112         }
 113         while (walk - res < MSDOS_NAME)
 114                 *walk++ = ' ';
 115
 116         return 0;
 117 }
 118
 119 /***** Locates a directory entry.  Uses unformatted name. */
 120 static int msdos_find(struct inode *dir, const unsigned char *name, int len,
 121                       struct fat_slot_info *sinfo)
 122 {
 123         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 124         unsigned char msdos_name[MSDOS_NAME];
 125         int err;
 126
 127         err = msdos_format_name(name, len, msdos_name, &sbi->options);
 128         if (err)
 129                 return -ENOENT;
 130
 131         err = fat_scan(dir, msdos_name, sinfo);
 132         if (!err && sbi->options.dotsOK) {
 133                 if (name[0] == '.') {
 134                         if (!(sinfo->de->attr & ATTR_HIDDEN))
 135                                 err = -ENOENT;
 136                 } else {
 137                         if (sinfo->de->attr & ATTR_HIDDEN)
 138                                 err = -ENOENT;
 139                 }
 140                 if (err)
 141                         brelse(sinfo->bh);
 142         }
 143         return err;
 144 }
 145
 146 /*
 147  * Compute the hash for the msdos name corresponding to the dentry.
 148  * Note: if the name is invalid, we leave the hash code unchanged so
 149  * that the existing dentry can be used. The msdos fs routines will
 150  * return ENOENT or EINVAL as appropriate.
 151  */
 152 static int msdos_hash(struct dentry *dentry, 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(struct dentry *dentry, struct qstr *a, struct qstr *b)
 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(a->name, a->len, a_msdos_name, options);
 175         if (error)
 176                 goto old_compare;
 177         error = msdos_format_name(b->name, b->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 (a->len == b->len)
 187                 error = memcmp(a->name, b->name, a->len);
 188         goto out;
 189 }
 190
 191 static 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                                    struct nameidata *nd)
 203 {
 204         struct super_block *sb = dir->i_sb;
 205         struct fat_slot_info sinfo;
 206         struct inode *inode = NULL;
 207         int res;
 208
 209         dentry->d_op = &msdos_dentry_operations;
 210
 211         lock_super(sb);
 212         res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 213         if (res == -ENOENT)
 214                 goto add;
 215         if (res < 0)
 216                 goto out;
 217         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 218         brelse(sinfo.bh);
 219         if (IS_ERR(inode)) {
 220                 res = PTR_ERR(inode);
 221                 goto out;
 222         }
 223 add:
 224         res = 0;
 225         dentry = d_splice_alias(inode, dentry);
 226         if (dentry)
 227                 dentry->d_op = &msdos_dentry_operations;
 228 out:
 229         unlock_super(sb);
 230         if (!res)
 231                 return dentry;
 232         return ERR_PTR(res);
 233 }
 234
 235 /***** Creates a directory entry (name is already formatted). */
 236 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 237                            int is_dir, int is_hid, int cluster,
 238                            struct timespec *ts, struct fat_slot_info *sinfo)
 239 {
 240         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 241         struct msdos_dir_entry de;
 242         __le16 time, date;
 243         int err;
 244
 245         memcpy(de.name, name, MSDOS_NAME);
 246         de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 247         if (is_hid)
 248                 de.attr |= ATTR_HIDDEN;
 249         de.lcase = 0;
 250         fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
 251         de.cdate = de.adate = 0;
 252         de.ctime = 0;
 253         de.ctime_cs = 0;
 254         de.time = time;
 255         de.date = date;
 256         de.start = cpu_to_le16(cluster);
 257         de.starthi = cpu_to_le16(cluster >> 16);
 258         de.size = 0;
 259
 260         err = fat_add_entries(dir, &de, 1, sinfo);
 261         if (err)
 262                 return err;
 263
 264         dir->i_ctime = dir->i_mtime = *ts;
 265         if (IS_DIRSYNC(dir))
 266                 (void)fat_sync_inode(dir);
 267         else
 268                 mark_inode_dirty(dir);
 269
 270         return 0;
 271 }
 272
 273 /***** Create a file */
 274 static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
 275                         struct nameidata *nd)
 276 {
 277         struct super_block *sb = dir->i_sb;
 278         struct inode *inode = NULL;
 279         struct fat_slot_info sinfo;
 280         struct timespec ts;
 281         unsigned char msdos_name[MSDOS_NAME];
 282         int err, is_hid;
 283
 284         lock_super(sb);
 285
 286         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 287                                 msdos_name, &MSDOS_SB(sb)->options);
 288         if (err)
 289                 goto out;
 290         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 291         /* Have to do it due to foo vs. .foo conflicts */
 292         if (!fat_scan(dir, msdos_name, &sinfo)) {
 293                 brelse(sinfo.bh);
 294                 err = -EINVAL;
 295                 goto out;
 296         }
 297
 298         ts = CURRENT_TIME_SEC;
 299         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 300         if (err)
 301                 goto out;
 302         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 303         brelse(sinfo.bh);
 304         if (IS_ERR(inode)) {
 305                 err = PTR_ERR(inode);
 306                 goto out;
 307         }
 308         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 309         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 310
 311         d_instantiate(dentry, inode);
 312 out:
 313         unlock_super(sb);
 314         if (!err)
 315                 err = fat_flush_inodes(sb, dir, inode);
 316         return err;
 317 }
 318
 319 /***** Remove a directory */
 320 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 321 {
 322         struct super_block *sb = dir->i_sb;
 323         struct inode *inode = dentry->d_inode;
 324         struct fat_slot_info sinfo;
 325         int err;
 326
 327         lock_super(sb);
 328         /*
 329          * Check whether the directory is not in use, then check
 330          * whether it is empty.
 331          */
 332         err = fat_dir_empty(inode);
 333         if (err)
 334                 goto out;
 335         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 336         if (err)
 337                 goto out;
 338
 339         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 340         if (err)
 341                 goto out;
 342         drop_nlink(dir);
 343
 344         clear_nlink(inode);
 345         inode->i_ctime = CURRENT_TIME_SEC;
 346         fat_detach(inode);
 347 out:
 348         unlock_super(sb);
 349         if (!err)
 350                 err = fat_flush_inodes(sb, dir, inode);
 351
 352         return err;
 353 }
 354
 355 /***** Make a directory */
 356 static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 357 {
 358         struct super_block *sb = dir->i_sb;
 359         struct fat_slot_info sinfo;
 360         struct inode *inode;
 361         unsigned char msdos_name[MSDOS_NAME];
 362         struct timespec ts;
 363         int err, is_hid, cluster;
 364
 365         lock_super(sb);
 366
 367         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 368                                 msdos_name, &MSDOS_SB(sb)->options);
 369         if (err)
 370                 goto out;
 371         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 372         /* foo vs .foo situation */
 373         if (!fat_scan(dir, msdos_name, &sinfo)) {
 374                 brelse(sinfo.bh);
 375                 err = -EINVAL;
 376                 goto out;
 377         }
 378
 379         ts = CURRENT_TIME_SEC;
 380         cluster = fat_alloc_new_dir(dir, &ts);
 381         if (cluster < 0) {
 382                 err = cluster;
 383                 goto out;
 384         }
 385         err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 386         if (err)
 387                 goto out_free;
 388         inc_nlink(dir);
 389
 390         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 391         brelse(sinfo.bh);
 392         if (IS_ERR(inode)) {
 393                 err = PTR_ERR(inode);
 394                 /* the directory was completed, just return a error */
 395                 goto out;
 396         }
 397         inode->i_nlink = 2;
 398         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 399         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 400
 401         d_instantiate(dentry, inode);
 402
 403         unlock_super(sb);
 404         fat_flush_inodes(sb, dir, inode);
 405         return 0;
 406
 407 out_free:
 408         fat_free_clusters(dir, cluster);
 409 out:
 410         unlock_super(sb);
 411         return err;
 412 }
 413
 414 /***** Unlink a file */
 415 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 416 {
 417         struct inode *inode = dentry->d_inode;
 418         struct super_block *sb= inode->i_sb;
 419         struct fat_slot_info sinfo;
 420         int err;
 421
 422         lock_super(sb);
 423         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 424         if (err)
 425                 goto out;
 426
 427         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 428         if (err)
 429                 goto out;
 430         clear_nlink(inode);
 431         inode->i_ctime = CURRENT_TIME_SEC;
 432         fat_detach(inode);
 433 out:
 434         unlock_super(sb);
 435         if (!err)
 436                 err = fat_flush_inodes(sb, dir, inode);
 437
 438         return err;
 439 }
 440
 441 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 442                            struct dentry *old_dentry,
 443                            struct inode *new_dir, unsigned char *new_name,
 444                            struct dentry *new_dentry, int is_hid)
 445 {
 446         struct buffer_head *dotdot_bh;
 447         struct msdos_dir_entry *dotdot_de;
 448         struct inode *old_inode, *new_inode;
 449         struct fat_slot_info old_sinfo, sinfo;
 450         struct timespec ts;
 451         loff_t dotdot_i_pos, new_i_pos;
 452         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 453
 454         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 455         old_inode = old_dentry->d_inode;
 456         new_inode = new_dentry->d_inode;
 457
 458         err = fat_scan(old_dir, old_name, &old_sinfo);
 459         if (err) {
 460                 err = -EIO;
 461                 goto out;
 462         }
 463
 464         is_dir = S_ISDIR(old_inode->i_mode);
 465         update_dotdot = (is_dir && old_dir != new_dir);
 466         if (update_dotdot) {
 467                 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
 468                                          &dotdot_i_pos) < 0) {
 469                         err = -EIO;
 470                         goto out;
 471                 }
 472         }
 473
 474         old_attrs = MSDOS_I(old_inode)->i_attrs;
 475         err = fat_scan(new_dir, new_name, &sinfo);
 476         if (!err) {
 477                 if (!new_inode) {
 478                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 479                         if (sinfo.de != old_sinfo.de) {
 480                                 err = -EINVAL;
 481                                 goto out;
 482                         }
 483                         if (is_hid)
 484                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 485                         else
 486                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 487                         if (IS_DIRSYNC(old_dir)) {
 488                                 err = fat_sync_inode(old_inode);
 489                                 if (err) {
 490                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 491                                         goto out;
 492                                 }
 493                         } else
 494                                 mark_inode_dirty(old_inode);
 495
 496                         old_dir->i_version++;
 497                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 498                         if (IS_DIRSYNC(old_dir))
 499                                 (void)fat_sync_inode(old_dir);
 500                         else
 501                                 mark_inode_dirty(old_dir);
 502                         goto out;
 503                 }
 504         }
 505
 506         ts = CURRENT_TIME_SEC;
 507         if (new_inode) {
 508                 if (err)
 509                         goto out;
 510                 if (is_dir) {
 511                         err = fat_dir_empty(new_inode);
 512                         if (err)
 513                                 goto out;
 514                 }
 515                 new_i_pos = MSDOS_I(new_inode)->i_pos;
 516                 fat_detach(new_inode);
 517         } else {
 518                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 519                                       &ts, &sinfo);
 520                 if (err)
 521                         goto out;
 522                 new_i_pos = sinfo.i_pos;
 523         }
 524         new_dir->i_version++;
 525
 526         fat_detach(old_inode);
 527         fat_attach(old_inode, new_i_pos);
 528         if (is_hid)
 529                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 530         else
 531                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 532         if (IS_DIRSYNC(new_dir)) {
 533                 err = fat_sync_inode(old_inode);
 534                 if (err)
 535                         goto error_inode;
 536         } else
 537                 mark_inode_dirty(old_inode);
 538
 539         if (update_dotdot) {
 540                 int start = MSDOS_I(new_dir)->i_logstart;
 541                 dotdot_de->start = cpu_to_le16(start);
 542                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 543                 mark_buffer_dirty(dotdot_bh);
 544                 if (IS_DIRSYNC(new_dir)) {
 545                         err = sync_dirty_buffer(dotdot_bh);
 546                         if (err)
 547                                 goto error_dotdot;
 548                 }
 549                 drop_nlink(old_dir);
 550                 if (!new_inode)
 551                         inc_nlink(new_dir);
 552         }
 553
 554         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 555         old_sinfo.bh = NULL;
 556         if (err)
 557                 goto error_dotdot;
 558         old_dir->i_version++;
 559         old_dir->i_ctime = old_dir->i_mtime = ts;
 560         if (IS_DIRSYNC(old_dir))
 561                 (void)fat_sync_inode(old_dir);
 562         else
 563                 mark_inode_dirty(old_dir);
 564
 565         if (new_inode) {
 566                 drop_nlink(new_inode);
 567                 if (is_dir)
 568                         drop_nlink(new_inode);
 569                 new_inode->i_ctime = ts;
 570         }
 571 out:
 572         brelse(sinfo.bh);
 573         brelse(dotdot_bh);
 574         brelse(old_sinfo.bh);
 575         return err;
 576
 577 error_dotdot:
 578         /* data cluster is shared, serious corruption */
 579         corrupt = 1;
 580
 581         if (update_dotdot) {
 582                 int start = MSDOS_I(old_dir)->i_logstart;
 583                 dotdot_de->start = cpu_to_le16(start);
 584                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 585                 mark_buffer_dirty(dotdot_bh);
 586                 corrupt |= sync_dirty_buffer(dotdot_bh);
 587         }
 588 error_inode:
 589         fat_detach(old_inode);
 590         fat_attach(old_inode, old_sinfo.i_pos);
 591         MSDOS_I(old_inode)->i_attrs = old_attrs;
 592         if (new_inode) {
 593                 fat_attach(new_inode, new_i_pos);
 594                 if (corrupt)
 595                         corrupt |= fat_sync_inode(new_inode);
 596         } else {
 597                 /*
 598                  * If new entry was not sharing the data cluster, it
 599                  * shouldn't be serious corruption.
 600                  */
 601                 int err2 = fat_remove_entries(new_dir, &sinfo);
 602                 if (corrupt)
 603                         corrupt |= err2;
 604                 sinfo.bh = NULL;
 605         }
 606         if (corrupt < 0) {
 607                 fat_fs_panic(new_dir->i_sb,
 608                              "%s: Filesystem corrupted (i_pos %lld)",
 609                              __func__, sinfo.i_pos);
 610         }
 611         goto out;
 612 }
 613
 614 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 615 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 616                         struct inode *new_dir, struct dentry *new_dentry)
 617 {
 618         struct super_block *sb = old_dir->i_sb;
 619         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 620         int err, is_hid;
 621
 622         lock_super(sb);
 623
 624         err = msdos_format_name(old_dentry->d_name.name,
 625                                 old_dentry->d_name.len, old_msdos_name,
 626                                 &MSDOS_SB(old_dir->i_sb)->options);
 627         if (err)
 628                 goto out;
 629         err = msdos_format_name(new_dentry->d_name.name,
 630                                 new_dentry->d_name.len, new_msdos_name,
 631                                 &MSDOS_SB(new_dir->i_sb)->options);
 632         if (err)
 633                 goto out;
 634
 635         is_hid =
 636              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 637
 638         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 639                               new_dir, new_msdos_name, new_dentry, is_hid);
 640 out:
 641         unlock_super(sb);
 642         if (!err)
 643                 err = fat_flush_inodes(sb, old_dir, new_dir);
 644         return err;
 645 }
 646
 647 static const struct inode_operations msdos_dir_inode_operations = {
 648         .create         = msdos_create,
 649         .lookup         = msdos_lookup,
 650         .unlink         = msdos_unlink,
 651         .mkdir          = msdos_mkdir,
 652         .rmdir          = msdos_rmdir,
 653         .rename         = msdos_rename,
 654         .setattr        = fat_setattr,
 655         .getattr        = fat_getattr,
 656 };
 657
 658 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 659 {
 660         int res;
 661
 662         res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
 663         if (res)
 664                 return res;
 665
 666         sb->s_flags |= MS_NOATIME;
 667         sb->s_root->d_op = &msdos_dentry_operations;
 668         return 0;
 669 }
 670
 671 static int msdos_get_sb(struct file_system_type *fs_type,
 672                         int flags, const char *dev_name,
 673                         void *data, struct vfsmount *mnt)
 674 {
 675         return get_sb_bdev(fs_type, flags, dev_name, data, msdos_fill_super,
 676                            mnt);
 677 }
 678
 679 static struct file_system_type msdos_fs_type = {
 680         .owner          = THIS_MODULE,
 681         .name           = "msdos",
 682         .get_sb         = msdos_get_sb,
 683         .kill_sb        = kill_block_super,
 684         .fs_flags       = FS_REQUIRES_DEV,
 685 };
 686
 687 static int __init init_msdos_fs(void)
 688 {
 689         return register_filesystem(&msdos_fs_type);
 690 }
 691
 692 static void __exit exit_msdos_fs(void)
 693 {
 694         unregister_filesystem(&msdos_fs_type);
 695 }
 696
 697 MODULE_LICENSE("GPL");
 698 MODULE_AUTHOR("Werner Almesberger");
 699 MODULE_DESCRIPTION("MS-DOS filesystem support");
 700
 701 module_init(init_msdos_fs)
 702 module_exit(exit_msdos_fs)