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 <linux/smp_lock.h>
  13 #include "fat.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 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                                    struct nameidata *nd)
 203 {
 204         struct super_block *sb = dir->i_sb;
 205         struct fat_slot_info sinfo;
 206         struct inode *inode;
 207         int err;
 208
 209         lock_super(sb);
 210
 211         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 212         if (err) {
 213                 if (err == -ENOENT) {
 214                         inode = NULL;
 215                         goto out;
 216                 }
 217                 goto error;
 218         }
 219
 220         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 221         brelse(sinfo.bh);
 222         if (IS_ERR(inode)) {
 223                 err = PTR_ERR(inode);
 224                 goto error;
 225         }
 226 out:
 227         unlock_super(sb);
 228         dentry->d_op = &msdos_dentry_operations;
 229         dentry = d_splice_alias(inode, dentry);
 230         if (dentry)
 231                 dentry->d_op = &msdos_dentry_operations;
 232         return dentry;
 233
 234 error:
 235         unlock_super(sb);
 236         return ERR_PTR(err);
 237 }
 238
 239 /***** Creates a directory entry (name is already formatted). */
 240 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 241                            int is_dir, int is_hid, int cluster,
 242                            struct timespec *ts, struct fat_slot_info *sinfo)
 243 {
 244         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 245         struct msdos_dir_entry de;
 246         __le16 time, date;
 247         int err;
 248
 249         memcpy(de.name, name, MSDOS_NAME);
 250         de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 251         if (is_hid)
 252                 de.attr |= ATTR_HIDDEN;
 253         de.lcase = 0;
 254         fat_time_unix2fat(sbi, ts, &time, &date, NULL);
 255         de.cdate = de.adate = 0;
 256         de.ctime = 0;
 257         de.ctime_cs = 0;
 258         de.time = time;
 259         de.date = date;
 260         de.start = cpu_to_le16(cluster);
 261         de.starthi = cpu_to_le16(cluster >> 16);
 262         de.size = 0;
 263
 264         err = fat_add_entries(dir, &de, 1, sinfo);
 265         if (err)
 266                 return err;
 267
 268         dir->i_ctime = dir->i_mtime = *ts;
 269         if (IS_DIRSYNC(dir))
 270                 (void)fat_sync_inode(dir);
 271         else
 272                 mark_inode_dirty(dir);
 273
 274         return 0;
 275 }
 276
 277 /***** Create a file */
 278 static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
 279                         struct nameidata *nd)
 280 {
 281         struct super_block *sb = dir->i_sb;
 282         struct inode *inode = NULL;
 283         struct fat_slot_info sinfo;
 284         struct timespec ts;
 285         unsigned char msdos_name[MSDOS_NAME];
 286         int err, is_hid;
 287
 288         lock_super(sb);
 289
 290         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 291                                 msdos_name, &MSDOS_SB(sb)->options);
 292         if (err)
 293                 goto out;
 294         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 295         /* Have to do it due to foo vs. .foo conflicts */
 296         if (!fat_scan(dir, msdos_name, &sinfo)) {
 297                 brelse(sinfo.bh);
 298                 err = -EINVAL;
 299                 goto out;
 300         }
 301
 302         ts = CURRENT_TIME_SEC;
 303         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 304         if (err)
 305                 goto out;
 306         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 307         brelse(sinfo.bh);
 308         if (IS_ERR(inode)) {
 309                 err = PTR_ERR(inode);
 310                 goto out;
 311         }
 312         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 313         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 314
 315         d_instantiate(dentry, inode);
 316 out:
 317         unlock_super(sb);
 318         if (!err)
 319                 err = fat_flush_inodes(sb, dir, inode);
 320         return err;
 321 }
 322
 323 /***** Remove a directory */
 324 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 325 {
 326         struct super_block *sb = dir->i_sb;
 327         struct inode *inode = dentry->d_inode;
 328         struct fat_slot_info sinfo;
 329         int err;
 330
 331         lock_super(sb);
 332         /*
 333          * Check whether the directory is not in use, then check
 334          * whether it is empty.
 335          */
 336         err = fat_dir_empty(inode);
 337         if (err)
 338                 goto out;
 339         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 340         if (err)
 341                 goto out;
 342
 343         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 344         if (err)
 345                 goto out;
 346         drop_nlink(dir);
 347
 348         clear_nlink(inode);
 349         inode->i_ctime = CURRENT_TIME_SEC;
 350         fat_detach(inode);
 351 out:
 352         unlock_super(sb);
 353         if (!err)
 354                 err = fat_flush_inodes(sb, dir, inode);
 355
 356         return err;
 357 }
 358
 359 /***** Make a directory */
 360 static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 361 {
 362         struct super_block *sb = dir->i_sb;
 363         struct fat_slot_info sinfo;
 364         struct inode *inode;
 365         unsigned char msdos_name[MSDOS_NAME];
 366         struct timespec ts;
 367         int err, is_hid, cluster;
 368
 369         lock_super(sb);
 370
 371         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 372                                 msdos_name, &MSDOS_SB(sb)->options);
 373         if (err)
 374                 goto out;
 375         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 376         /* foo vs .foo situation */
 377         if (!fat_scan(dir, msdos_name, &sinfo)) {
 378                 brelse(sinfo.bh);
 379                 err = -EINVAL;
 380                 goto out;
 381         }
 382
 383         ts = CURRENT_TIME_SEC;
 384         cluster = fat_alloc_new_dir(dir, &ts);
 385         if (cluster < 0) {
 386                 err = cluster;
 387                 goto out;
 388         }
 389         err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 390         if (err)
 391                 goto out_free;
 392         inc_nlink(dir);
 393
 394         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 395         brelse(sinfo.bh);
 396         if (IS_ERR(inode)) {
 397                 err = PTR_ERR(inode);
 398                 /* the directory was completed, just return a error */
 399                 goto out;
 400         }
 401         inode->i_nlink = 2;
 402         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 403         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 404
 405         d_instantiate(dentry, inode);
 406
 407         unlock_super(sb);
 408         fat_flush_inodes(sb, dir, inode);
 409         return 0;
 410
 411 out_free:
 412         fat_free_clusters(dir, cluster);
 413 out:
 414         unlock_super(sb);
 415         return err;
 416 }
 417
 418 /***** Unlink a file */
 419 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 420 {
 421         struct inode *inode = dentry->d_inode;
 422         struct super_block *sb= inode->i_sb;
 423         struct fat_slot_info sinfo;
 424         int err;
 425
 426         lock_super(sb);
 427         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 428         if (err)
 429                 goto out;
 430
 431         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 432         if (err)
 433                 goto out;
 434         clear_nlink(inode);
 435         inode->i_ctime = CURRENT_TIME_SEC;
 436         fat_detach(inode);
 437 out:
 438         unlock_super(sb);
 439         if (!err)
 440                 err = fat_flush_inodes(sb, dir, inode);
 441
 442         return err;
 443 }
 444
 445 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 446                            struct dentry *old_dentry,
 447                            struct inode *new_dir, unsigned char *new_name,
 448                            struct dentry *new_dentry, int is_hid)
 449 {
 450         struct buffer_head *dotdot_bh;
 451         struct msdos_dir_entry *dotdot_de;
 452         struct inode *old_inode, *new_inode;
 453         struct fat_slot_info old_sinfo, sinfo;
 454         struct timespec ts;
 455         loff_t dotdot_i_pos, new_i_pos;
 456         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 457
 458         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 459         old_inode = old_dentry->d_inode;
 460         new_inode = new_dentry->d_inode;
 461
 462         err = fat_scan(old_dir, old_name, &old_sinfo);
 463         if (err) {
 464                 err = -EIO;
 465                 goto out;
 466         }
 467
 468         is_dir = S_ISDIR(old_inode->i_mode);
 469         update_dotdot = (is_dir && old_dir != new_dir);
 470         if (update_dotdot) {
 471                 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
 472                                          &dotdot_i_pos) < 0) {
 473                         err = -EIO;
 474                         goto out;
 475                 }
 476         }
 477
 478         old_attrs = MSDOS_I(old_inode)->i_attrs;
 479         err = fat_scan(new_dir, new_name, &sinfo);
 480         if (!err) {
 481                 if (!new_inode) {
 482                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 483                         if (sinfo.de != old_sinfo.de) {
 484                                 err = -EINVAL;
 485                                 goto out;
 486                         }
 487                         if (is_hid)
 488                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 489                         else
 490                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 491                         if (IS_DIRSYNC(old_dir)) {
 492                                 err = fat_sync_inode(old_inode);
 493                                 if (err) {
 494                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 495                                         goto out;
 496                                 }
 497                         } else
 498                                 mark_inode_dirty(old_inode);
 499
 500                         old_dir->i_version++;
 501                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 502                         if (IS_DIRSYNC(old_dir))
 503                                 (void)fat_sync_inode(old_dir);
 504                         else
 505                                 mark_inode_dirty(old_dir);
 506                         goto out;
 507                 }
 508         }
 509
 510         ts = CURRENT_TIME_SEC;
 511         if (new_inode) {
 512                 if (err)
 513                         goto out;
 514                 if (is_dir) {
 515                         err = fat_dir_empty(new_inode);
 516                         if (err)
 517                                 goto out;
 518                 }
 519                 new_i_pos = MSDOS_I(new_inode)->i_pos;
 520                 fat_detach(new_inode);
 521         } else {
 522                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 523                                       &ts, &sinfo);
 524                 if (err)
 525                         goto out;
 526                 new_i_pos = sinfo.i_pos;
 527         }
 528         new_dir->i_version++;
 529
 530         fat_detach(old_inode);
 531         fat_attach(old_inode, new_i_pos);
 532         if (is_hid)
 533                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 534         else
 535                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 536         if (IS_DIRSYNC(new_dir)) {
 537                 err = fat_sync_inode(old_inode);
 538                 if (err)
 539                         goto error_inode;
 540         } else
 541                 mark_inode_dirty(old_inode);
 542
 543         if (update_dotdot) {
 544                 int start = MSDOS_I(new_dir)->i_logstart;
 545                 dotdot_de->start = cpu_to_le16(start);
 546                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 547                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 548                 if (IS_DIRSYNC(new_dir)) {
 549                         err = sync_dirty_buffer(dotdot_bh);
 550                         if (err)
 551                                 goto error_dotdot;
 552                 }
 553                 drop_nlink(old_dir);
 554                 if (!new_inode)
 555                         inc_nlink(new_dir);
 556         }
 557
 558         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 559         old_sinfo.bh = NULL;
 560         if (err)
 561                 goto error_dotdot;
 562         old_dir->i_version++;
 563         old_dir->i_ctime = old_dir->i_mtime = ts;
 564         if (IS_DIRSYNC(old_dir))
 565                 (void)fat_sync_inode(old_dir);
 566         else
 567                 mark_inode_dirty(old_dir);
 568
 569         if (new_inode) {
 570                 drop_nlink(new_inode);
 571                 if (is_dir)
 572                         drop_nlink(new_inode);
 573                 new_inode->i_ctime = ts;
 574         }
 575 out:
 576         brelse(sinfo.bh);
 577         brelse(dotdot_bh);
 578         brelse(old_sinfo.bh);
 579         return err;
 580
 581 error_dotdot:
 582         /* data cluster is shared, serious corruption */
 583         corrupt = 1;
 584
 585         if (update_dotdot) {
 586                 int start = MSDOS_I(old_dir)->i_logstart;
 587                 dotdot_de->start = cpu_to_le16(start);
 588                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 589                 mark_buffer_dirty_inode(dotdot_bh, old_inode);
 590                 corrupt |= sync_dirty_buffer(dotdot_bh);
 591         }
 592 error_inode:
 593         fat_detach(old_inode);
 594         fat_attach(old_inode, old_sinfo.i_pos);
 595         MSDOS_I(old_inode)->i_attrs = old_attrs;
 596         if (new_inode) {
 597                 fat_attach(new_inode, new_i_pos);
 598                 if (corrupt)
 599                         corrupt |= fat_sync_inode(new_inode);
 600         } else {
 601                 /*
 602                  * If new entry was not sharing the data cluster, it
 603                  * shouldn't be serious corruption.
 604                  */
 605                 int err2 = fat_remove_entries(new_dir, &sinfo);
 606                 if (corrupt)
 607                         corrupt |= err2;
 608                 sinfo.bh = NULL;
 609         }
 610         if (corrupt < 0) {
 611                 fat_fs_error(new_dir->i_sb,
 612                              "%s: Filesystem corrupted (i_pos %lld)",
 613                              __func__, sinfo.i_pos);
 614         }
 615         goto out;
 616 }
 617
 618 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 619 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 620                         struct inode *new_dir, struct dentry *new_dentry)
 621 {
 622         struct super_block *sb = old_dir->i_sb;
 623         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 624         int err, is_hid;
 625
 626         lock_super(sb);
 627
 628         err = msdos_format_name(old_dentry->d_name.name,
 629                                 old_dentry->d_name.len, old_msdos_name,
 630                                 &MSDOS_SB(old_dir->i_sb)->options);
 631         if (err)
 632                 goto out;
 633         err = msdos_format_name(new_dentry->d_name.name,
 634                                 new_dentry->d_name.len, new_msdos_name,
 635                                 &MSDOS_SB(new_dir->i_sb)->options);
 636         if (err)
 637                 goto out;
 638
 639         is_hid =
 640              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 641
 642         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 643                               new_dir, new_msdos_name, new_dentry, is_hid);
 644 out:
 645         unlock_super(sb);
 646         if (!err)
 647                 err = fat_flush_inodes(sb, old_dir, new_dir);
 648         return err;
 649 }
 650
 651 static const struct inode_operations msdos_dir_inode_operations = {
 652         .create         = msdos_create,
 653         .lookup         = msdos_lookup,
 654         .unlink         = msdos_unlink,
 655         .mkdir          = msdos_mkdir,
 656         .rmdir          = msdos_rmdir,
 657         .rename         = msdos_rename,
 658         .setattr        = fat_setattr,
 659         .getattr        = fat_getattr,
 660 };
 661
 662 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 663 {
 664         int res;
 665
 666         res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
 667         if (res)
 668                 return res;
 669
 670         sb->s_flags |= MS_NOATIME;
 671         sb->s_root->d_op = &msdos_dentry_operations;
 672         return 0;
 673 }
 674
 675 static int msdos_get_sb(struct file_system_type *fs_type,
 676                         int flags, const char *dev_name,
 677                         void *data, struct vfsmount *mnt)
 678 {
 679         return get_sb_bdev(fs_type, flags, dev_name, data, msdos_fill_super,
 680                            mnt);
 681 }
 682
 683 static struct file_system_type msdos_fs_type = {
 684         .owner          = THIS_MODULE,
 685         .name           = "msdos",
 686         .get_sb         = msdos_get_sb,
 687         .kill_sb        = kill_block_super,
 688         .fs_flags       = FS_REQUIRES_DEV,
 689 };
 690
 691 static int __init init_msdos_fs(void)
 692 {
 693         return register_filesystem(&msdos_fs_type);
 694 }
 695
 696 static void __exit exit_msdos_fs(void)
 697 {
 698         unregister_filesystem(&msdos_fs_type);
 699 }
 700
 701 MODULE_LICENSE("GPL");
 702 MODULE_AUTHOR("Werner Almesberger");
 703 MODULE_DESCRIPTION("MS-DOS filesystem support");
 704
 705 module_init(init_msdos_fs)
 706 module_exit(exit_msdos_fs)