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                                    struct nameidata *nd)
 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         de.start = cpu_to_le16(cluster);
 250         de.starthi = cpu_to_le16(cluster >> 16);
 251         de.size = 0;
 252
 253         err = fat_add_entries(dir, &de, 1, sinfo);
 254         if (err)
 255                 return err;
 256
 257         dir->i_ctime = dir->i_mtime = *ts;
 258         if (IS_DIRSYNC(dir))
 259                 (void)fat_sync_inode(dir);
 260         else
 261                 mark_inode_dirty(dir);
 262
 263         return 0;
 264 }
 265
 266 /***** Create a file */
 267 static int msdos_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 268                         struct nameidata *nd)
 269 {
 270         struct super_block *sb = dir->i_sb;
 271         struct inode *inode = NULL;
 272         struct fat_slot_info sinfo;
 273         struct timespec ts;
 274         unsigned char msdos_name[MSDOS_NAME];
 275         int err, is_hid;
 276
 277         lock_super(sb);
 278
 279         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 280                                 msdos_name, &MSDOS_SB(sb)->options);
 281         if (err)
 282                 goto out;
 283         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 284         /* Have to do it due to foo vs. .foo conflicts */
 285         if (!fat_scan(dir, msdos_name, &sinfo)) {
 286                 brelse(sinfo.bh);
 287                 err = -EINVAL;
 288                 goto out;
 289         }
 290
 291         ts = CURRENT_TIME_SEC;
 292         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 293         if (err)
 294                 goto out;
 295         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 296         brelse(sinfo.bh);
 297         if (IS_ERR(inode)) {
 298                 err = PTR_ERR(inode);
 299                 goto out;
 300         }
 301         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 302         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 303
 304         d_instantiate(dentry, inode);
 305 out:
 306         unlock_super(sb);
 307         if (!err)
 308                 err = fat_flush_inodes(sb, dir, inode);
 309         return err;
 310 }
 311
 312 /***** Remove a directory */
 313 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 314 {
 315         struct super_block *sb = dir->i_sb;
 316         struct inode *inode = dentry->d_inode;
 317         struct fat_slot_info sinfo;
 318         int err;
 319
 320         lock_super(sb);
 321         /*
 322          * Check whether the directory is not in use, then check
 323          * whether it is empty.
 324          */
 325         err = fat_dir_empty(inode);
 326         if (err)
 327                 goto out;
 328         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 329         if (err)
 330                 goto out;
 331
 332         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 333         if (err)
 334                 goto out;
 335         drop_nlink(dir);
 336
 337         clear_nlink(inode);
 338         inode->i_ctime = CURRENT_TIME_SEC;
 339         fat_detach(inode);
 340 out:
 341         unlock_super(sb);
 342         if (!err)
 343                 err = fat_flush_inodes(sb, dir, inode);
 344
 345         return err;
 346 }
 347
 348 /***** Make a directory */
 349 static int msdos_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 350 {
 351         struct super_block *sb = dir->i_sb;
 352         struct fat_slot_info sinfo;
 353         struct inode *inode;
 354         unsigned char msdos_name[MSDOS_NAME];
 355         struct timespec ts;
 356         int err, is_hid, cluster;
 357
 358         lock_super(sb);
 359
 360         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 361                                 msdos_name, &MSDOS_SB(sb)->options);
 362         if (err)
 363                 goto out;
 364         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 365         /* foo vs .foo situation */
 366         if (!fat_scan(dir, msdos_name, &sinfo)) {
 367                 brelse(sinfo.bh);
 368                 err = -EINVAL;
 369                 goto out;
 370         }
 371
 372         ts = CURRENT_TIME_SEC;
 373         cluster = fat_alloc_new_dir(dir, &ts);
 374         if (cluster < 0) {
 375                 err = cluster;
 376                 goto out;
 377         }
 378         err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 379         if (err)
 380                 goto out_free;
 381         inc_nlink(dir);
 382
 383         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 384         brelse(sinfo.bh);
 385         if (IS_ERR(inode)) {
 386                 err = PTR_ERR(inode);
 387                 /* the directory was completed, just return a error */
 388                 goto out;
 389         }
 390         set_nlink(inode, 2);
 391         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 392         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 393
 394         d_instantiate(dentry, inode);
 395
 396         unlock_super(sb);
 397         fat_flush_inodes(sb, dir, inode);
 398         return 0;
 399
 400 out_free:
 401         fat_free_clusters(dir, cluster);
 402 out:
 403         unlock_super(sb);
 404         return err;
 405 }
 406
 407 /***** Unlink a file */
 408 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 409 {
 410         struct inode *inode = dentry->d_inode;
 411         struct super_block *sb= inode->i_sb;
 412         struct fat_slot_info sinfo;
 413         int err;
 414
 415         lock_super(sb);
 416         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 417         if (err)
 418                 goto out;
 419
 420         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 421         if (err)
 422                 goto out;
 423         clear_nlink(inode);
 424         inode->i_ctime = CURRENT_TIME_SEC;
 425         fat_detach(inode);
 426 out:
 427         unlock_super(sb);
 428         if (!err)
 429                 err = fat_flush_inodes(sb, dir, inode);
 430
 431         return err;
 432 }
 433
 434 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 435                            struct dentry *old_dentry,
 436                            struct inode *new_dir, unsigned char *new_name,
 437                            struct dentry *new_dentry, int is_hid)
 438 {
 439         struct buffer_head *dotdot_bh;
 440         struct msdos_dir_entry *dotdot_de;
 441         struct inode *old_inode, *new_inode;
 442         struct fat_slot_info old_sinfo, sinfo;
 443         struct timespec ts;
 444         loff_t dotdot_i_pos, new_i_pos;
 445         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 446
 447         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 448         old_inode = old_dentry->d_inode;
 449         new_inode = new_dentry->d_inode;
 450
 451         err = fat_scan(old_dir, old_name, &old_sinfo);
 452         if (err) {
 453                 err = -EIO;
 454                 goto out;
 455         }
 456
 457         is_dir = S_ISDIR(old_inode->i_mode);
 458         update_dotdot = (is_dir && old_dir != new_dir);
 459         if (update_dotdot) {
 460                 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
 461                                          &dotdot_i_pos) < 0) {
 462                         err = -EIO;
 463                         goto out;
 464                 }
 465         }
 466
 467         old_attrs = MSDOS_I(old_inode)->i_attrs;
 468         err = fat_scan(new_dir, new_name, &sinfo);
 469         if (!err) {
 470                 if (!new_inode) {
 471                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 472                         if (sinfo.de != old_sinfo.de) {
 473                                 err = -EINVAL;
 474                                 goto out;
 475                         }
 476                         if (is_hid)
 477                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 478                         else
 479                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 480                         if (IS_DIRSYNC(old_dir)) {
 481                                 err = fat_sync_inode(old_inode);
 482                                 if (err) {
 483                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 484                                         goto out;
 485                                 }
 486                         } else
 487                                 mark_inode_dirty(old_inode);
 488
 489                         old_dir->i_version++;
 490                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 491                         if (IS_DIRSYNC(old_dir))
 492                                 (void)fat_sync_inode(old_dir);
 493                         else
 494                                 mark_inode_dirty(old_dir);
 495                         goto out;
 496                 }
 497         }
 498
 499         ts = CURRENT_TIME_SEC;
 500         if (new_inode) {
 501                 if (err)
 502                         goto out;
 503                 if (is_dir) {
 504                         err = fat_dir_empty(new_inode);
 505                         if (err)
 506                                 goto out;
 507                 }
 508                 new_i_pos = MSDOS_I(new_inode)->i_pos;
 509                 fat_detach(new_inode);
 510         } else {
 511                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 512                                       &ts, &sinfo);
 513                 if (err)
 514                         goto out;
 515                 new_i_pos = sinfo.i_pos;
 516         }
 517         new_dir->i_version++;
 518
 519         fat_detach(old_inode);
 520         fat_attach(old_inode, new_i_pos);
 521         if (is_hid)
 522                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 523         else
 524                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 525         if (IS_DIRSYNC(new_dir)) {
 526                 err = fat_sync_inode(old_inode);
 527                 if (err)
 528                         goto error_inode;
 529         } else
 530                 mark_inode_dirty(old_inode);
 531
 532         if (update_dotdot) {
 533                 int start = MSDOS_I(new_dir)->i_logstart;
 534                 dotdot_de->start = cpu_to_le16(start);
 535                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 536                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 537                 if (IS_DIRSYNC(new_dir)) {
 538                         err = sync_dirty_buffer(dotdot_bh);
 539                         if (err)
 540                                 goto error_dotdot;
 541                 }
 542                 drop_nlink(old_dir);
 543                 if (!new_inode)
 544                         inc_nlink(new_dir);
 545         }
 546
 547         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 548         old_sinfo.bh = NULL;
 549         if (err)
 550                 goto error_dotdot;
 551         old_dir->i_version++;
 552         old_dir->i_ctime = old_dir->i_mtime = ts;
 553         if (IS_DIRSYNC(old_dir))
 554                 (void)fat_sync_inode(old_dir);
 555         else
 556                 mark_inode_dirty(old_dir);
 557
 558         if (new_inode) {
 559                 drop_nlink(new_inode);
 560                 if (is_dir)
 561                         drop_nlink(new_inode);
 562                 new_inode->i_ctime = ts;
 563         }
 564 out:
 565         brelse(sinfo.bh);
 566         brelse(dotdot_bh);
 567         brelse(old_sinfo.bh);
 568         return err;
 569
 570 error_dotdot:
 571         /* data cluster is shared, serious corruption */
 572         corrupt = 1;
 573
 574         if (update_dotdot) {
 575                 int start = MSDOS_I(old_dir)->i_logstart;
 576                 dotdot_de->start = cpu_to_le16(start);
 577                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 578                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 579                 corrupt |= sync_dirty_buffer(dotdot_bh);
 580         }
 581 error_inode:
 582         fat_detach(old_inode);
 583         fat_attach(old_inode, old_sinfo.i_pos);
 584         MSDOS_I(old_inode)->i_attrs = old_attrs;
 585         if (new_inode) {
 586                 fat_attach(new_inode, new_i_pos);
 587                 if (corrupt)
 588                         corrupt |= fat_sync_inode(new_inode);
 589         } else {
 590                 /*
 591                  * If new entry was not sharing the data cluster, it
 592                  * shouldn't be serious corruption.
 593                  */
 594                 int err2 = fat_remove_entries(new_dir, &sinfo);
 595                 if (corrupt)
 596                         corrupt |= err2;
 597                 sinfo.bh = NULL;
 598         }
 599         if (corrupt < 0) {
 600                 fat_fs_error(new_dir->i_sb,
 601                              "%s: Filesystem corrupted (i_pos %lld)",
 602                              __func__, sinfo.i_pos);
 603         }
 604         goto out;
 605 }
 606
 607 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 608 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 609                         struct inode *new_dir, struct dentry *new_dentry)
 610 {
 611         struct super_block *sb = old_dir->i_sb;
 612         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 613         int err, is_hid;
 614
 615         lock_super(sb);
 616
 617         err = msdos_format_name(old_dentry->d_name.name,
 618                                 old_dentry->d_name.len, old_msdos_name,
 619                                 &MSDOS_SB(old_dir->i_sb)->options);
 620         if (err)
 621                 goto out;
 622         err = msdos_format_name(new_dentry->d_name.name,
 623                                 new_dentry->d_name.len, new_msdos_name,
 624                                 &MSDOS_SB(new_dir->i_sb)->options);
 625         if (err)
 626                 goto out;
 627
 628         is_hid =
 629              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 630
 631         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 632                               new_dir, new_msdos_name, new_dentry, is_hid);
 633 out:
 634         unlock_super(sb);
 635         if (!err)
 636                 err = fat_flush_inodes(sb, old_dir, new_dir);
 637         return err;
 638 }
 639
 640 static const struct inode_operations msdos_dir_inode_operations = {
 641         .create         = msdos_create,
 642         .lookup         = msdos_lookup,
 643         .unlink         = msdos_unlink,
 644         .mkdir          = msdos_mkdir,
 645         .rmdir          = msdos_rmdir,
 646         .rename         = msdos_rename,
 647         .setattr        = fat_setattr,
 648         .getattr        = fat_getattr,
 649 };
 650
 651 static void setup(struct super_block *sb)
 652 {
 653         MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
 654         sb->s_d_op = &msdos_dentry_operations;
 655         sb->s_flags |= MS_NOATIME;
 656 }
 657
 658 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 659 {
 660         return fat_fill_super(sb, data, silent, 0, setup);
 661 }
 662
 663 static struct dentry *msdos_mount(struct file_system_type *fs_type,
 664                         int flags, const char *dev_name,
 665                         void *data)
 666 {
 667         return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
 668 }
 669
 670 static struct file_system_type msdos_fs_type = {
 671         .owner          = THIS_MODULE,
 672         .name           = "msdos",
 673         .mount          = msdos_mount,
 674         .kill_sb        = kill_block_super,
 675         .fs_flags       = FS_REQUIRES_DEV,
 676 };
 677
 678 static int __init init_msdos_fs(void)
 679 {
 680         return register_filesystem(&msdos_fs_type);
 681 }
 682
 683 static void __exit exit_msdos_fs(void)
 684 {
 685         unregister_filesystem(&msdos_fs_type);
 686 }
 687
 688 MODULE_LICENSE("GPL");
 689 MODULE_AUTHOR("Werner Almesberger");
 690 MODULE_DESCRIPTION("MS-DOS filesystem support");
 691
 692 module_init(init_msdos_fs)
 693 module_exit(exit_msdos_fs)