release/src-rt-6.x/linux/linux-2.6/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_pc[] = "+=,; ";
  18 /* GEMDOS is less restrictive */
  19 static unsigned char bad_if_strict_atari[] = " ";
  20
  21 #define bad_if_strict(opts) \
  22         ((opts)->atari ? bad_if_strict_atari : bad_if_strict_pc)
  23
  24 /***** Formats an MS-DOS file name. Rejects invalid names. */
  25 static int msdos_format_name(const unsigned char *name, int len,
  26                              unsigned char *res, struct fat_mount_options *opts)
  27         /*
  28          * name is the proposed name, len is its length, res is
  29          * the resulting name, opts->name_check is either (r)elaxed,
  30          * (n)ormal or (s)trict, opts->dotsOK allows dots at the
  31          * beginning of name (for hidden files)
  32          */
  33 {
  34         unsigned char *walk;
  35         unsigned char c;
  36         int space;
  37
  38         if (name[0] == '.') {   /* dotfile because . and .. already done */
  39                 if (opts->dotsOK) {
  40                         /* Get rid of dot - test for it elsewhere */
  41                         name++;
  42                         len--;
  43                 } else if (!opts->atari)
  44                         return -EINVAL;
  45         }
  46         /*
  47          * disallow names that _really_ start with a dot for MS-DOS,
  48          * GEMDOS does not care
  49          */
  50         space = !opts->atari;
  51         c = 0;
  52         for (walk = res; len && walk - res < 8; walk++) {
  53                 c = *name++;
  54                 len--;
  55                 if (opts->name_check != 'r' && strchr(bad_chars, c))
  56                         return -EINVAL;
  57                 if (opts->name_check == 's' && strchr(bad_if_strict(opts), c))
  58                         return -EINVAL;
  59                 if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
  60                         return -EINVAL;
  61                 if (c < ' ' || c == ':' || c == '\\')
  62                         return -EINVAL;
  63         /*
  64          * 0xE5 is legal as a first character, but we must substitute
  65          * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
  66          * does this.
  67          * It seems that Microsoft hacked DOS to support non-US
  68          * characters after the 0xE5 character was already in use to
  69          * mark deleted files.
  70          */
  71                 if ((res == walk) && (c == 0xE5))
  72                         c = 0x05;
  73                 if (c == '.')
  74                         break;
  75                 space = (c == ' ');
  76                 *walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
  77         }
  78         if (space)
  79                 return -EINVAL;
  80         if (opts->name_check == 's' && len && c != '.') {
  81                 c = *name++;
  82                 len--;
  83                 if (c != '.')
  84                         return -EINVAL;
  85         }
  86         while (c != '.' && len--)
  87                 c = *name++;
  88         if (c == '.') {
  89                 while (walk - res < 8)
  90                         *walk++ = ' ';
  91                 while (len > 0 && walk - res < MSDOS_NAME) {
  92                         c = *name++;
  93                         len--;
  94                         if (opts->name_check != 'r' && strchr(bad_chars, c))
  95                                 return -EINVAL;
  96                         if (opts->name_check == 's' &&
  97                             strchr(bad_if_strict(opts), c))
  98                                 return -EINVAL;
  99                         if (c < ' ' || c == ':' || c == '\\')
 100                                 return -EINVAL;
 101                         if (c == '.') {
 102                                 if (opts->name_check == 's')
 103                                         return -EINVAL;
 104                                 break;
 105                         }
 106                         if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
 107                                 return -EINVAL;
 108                         space = c == ' ';
 109                         if (!opts->nocase && c >= 'a' && c <= 'z')
 110                                 *walk++ = c - 32;
 111                         else
 112                                 *walk++ = c;
 113                 }
 114                 if (space)
 115                         return -EINVAL;
 116                 if (opts->name_check == 's' && len)
 117                         return -EINVAL;
 118         }
 119         while (walk - res < MSDOS_NAME)
 120                 *walk++ = ' ';
 121
 122         return 0;
 123 }
 124
 125 /***** Locates a directory entry.  Uses unformatted name. */
 126 static int msdos_find(struct inode *dir, const unsigned char *name, int len,
 127                       struct fat_slot_info *sinfo)
 128 {
 129         struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 130         unsigned char msdos_name[MSDOS_NAME];
 131         int err;
 132
 133         err = msdos_format_name(name, len, msdos_name, &sbi->options);
 134         if (err)
 135                 return -ENOENT;
 136
 137         err = fat_scan(dir, msdos_name, sinfo);
 138         if (!err && sbi->options.dotsOK) {
 139                 if (name[0] == '.') {
 140                         if (!(sinfo->de->attr & ATTR_HIDDEN))
 141                                 err = -ENOENT;
 142                 } else {
 143                         if (sinfo->de->attr & ATTR_HIDDEN)
 144                                 err = -ENOENT;
 145                 }
 146                 if (err)
 147                         brelse(sinfo->bh);
 148         }
 149         return err;
 150 }
 151
 152 /*
 153  * Compute the hash for the msdos name corresponding to the dentry.
 154  * Note: if the name is invalid, we leave the hash code unchanged so
 155  * that the existing dentry can be used. The msdos fs routines will
 156  * return ENOENT or EINVAL as appropriate.
 157  */
 158 static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
 159 {
 160         struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 161         unsigned char msdos_name[MSDOS_NAME];
 162         int error;
 163
 164         error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
 165         if (!error)
 166                 qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
 167         return 0;
 168 }
 169
 170 /*
 171  * Compare two msdos names. If either of the names are invalid,
 172  * we fall back to doing the standard name comparison.
 173  */
 174 static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
 175 {
 176         struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 177         unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 178         int error;
 179
 180         error = msdos_format_name(a->name, a->len, a_msdos_name, options);
 181         if (error)
 182                 goto old_compare;
 183         error = msdos_format_name(b->name, b->len, b_msdos_name, options);
 184         if (error)
 185                 goto old_compare;
 186         error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
 187 out:
 188         return error;
 189
 190 old_compare:
 191         error = 1;
 192         if (a->len == b->len)
 193                 error = memcmp(a->name, b->name, a->len);
 194         goto out;
 195 }
 196
 197 static struct dentry_operations msdos_dentry_operations = {
 198         .d_hash         = msdos_hash,
 199         .d_compare      = msdos_cmp,
 200 };
 201
 202 /*
 203  * AV. Wrappers for FAT sb operations. Is it wise?
 204  */
 205
 206 /***** Get inode using directory and name */
 207 static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
 208                                    struct nameidata *nd)
 209 {
 210         struct super_block *sb = dir->i_sb;
 211         struct fat_slot_info sinfo;
 212         struct inode *inode = NULL;
 213         int res;
 214
 215         dentry->d_op = &msdos_dentry_operations;
 216
 217         lock_super(sb);
 218         res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 219         if (res == -ENOENT)
 220                 goto add;
 221         if (res < 0)
 222                 goto out;
 223         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 224         brelse(sinfo.bh);
 225         if (IS_ERR(inode)) {
 226                 res = PTR_ERR(inode);
 227                 goto out;
 228         }
 229 add:
 230         res = 0;
 231         dentry = d_splice_alias(inode, dentry);
 232         if (dentry)
 233                 dentry->d_op = &msdos_dentry_operations;
 234 out:
 235         unlock_super(sb);
 236         if (!res)
 237                 return dentry;
 238         return ERR_PTR(res);
 239 }
 240
 241 /***** Creates a directory entry (name is already formatted). */
 242 static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 243                            int is_dir, int is_hid, int cluster,
 244                            struct timespec *ts, struct fat_slot_info *sinfo)
 245 {
 246         struct msdos_dir_entry de;
 247         __le16 time, date;
 248         int err;
 249
 250         memcpy(de.name, name, MSDOS_NAME);
 251         de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 252         if (is_hid)
 253                 de.attr |= ATTR_HIDDEN;
 254         de.lcase = 0;
 255         fat_date_unix2dos(ts->tv_sec, &time, &date);
 256         de.cdate = de.adate = 0;
 257         de.ctime = 0;
 258         de.ctime_cs = 0;
 259         de.time = time;
 260         de.date = date;
 261         de.start = cpu_to_le16(cluster);
 262         de.starthi = cpu_to_le16(cluster >> 16);
 263         de.size = 0;
 264
 265         err = fat_add_entries(dir, &de, 1, sinfo);
 266         if (err)
 267                 return err;
 268
 269         dir->i_ctime = dir->i_mtime = *ts;
 270         if (IS_DIRSYNC(dir))
 271                 (void)fat_sync_inode(dir);
 272         else
 273                 mark_inode_dirty(dir);
 274
 275         return 0;
 276 }
 277
 278 /***** Create a file */
 279 static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
 280                         struct nameidata *nd)
 281 {
 282         struct super_block *sb = dir->i_sb;
 283         struct inode *inode = NULL;
 284         struct fat_slot_info sinfo;
 285         struct timespec ts;
 286         unsigned char msdos_name[MSDOS_NAME];
 287         int err, is_hid;
 288
 289         lock_super(sb);
 290
 291         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 292                                 msdos_name, &MSDOS_SB(sb)->options);
 293         if (err)
 294                 goto out;
 295         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 296         /* Have to do it due to foo vs. .foo conflicts */
 297         if (!fat_scan(dir, msdos_name, &sinfo)) {
 298                 brelse(sinfo.bh);
 299                 err = -EINVAL;
 300                 goto out;
 301         }
 302
 303         ts = CURRENT_TIME_SEC;
 304         err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 305         if (err)
 306                 goto out;
 307         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 308         brelse(sinfo.bh);
 309         if (IS_ERR(inode)) {
 310                 err = PTR_ERR(inode);
 311                 goto out;
 312         }
 313         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 314         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 315
 316         d_instantiate(dentry, inode);
 317 out:
 318         unlock_super(sb);
 319         if (!err)
 320                 err = fat_flush_inodes(sb, dir, inode);
 321         return err;
 322 }
 323
 324 /***** Remove a directory */
 325 static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 326 {
 327         struct super_block *sb = dir->i_sb;
 328         struct inode *inode = dentry->d_inode;
 329         struct fat_slot_info sinfo;
 330         int err;
 331
 332         lock_super(sb);
 333         /*
 334          * Check whether the directory is not in use, then check
 335          * whether it is empty.
 336          */
 337         err = fat_dir_empty(inode);
 338         if (err)
 339                 goto out;
 340         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 341         if (err)
 342                 goto out;
 343
 344         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 345         if (err)
 346                 goto out;
 347         drop_nlink(dir);
 348
 349         clear_nlink(inode);
 350         inode->i_ctime = CURRENT_TIME_SEC;
 351         fat_detach(inode);
 352 out:
 353         unlock_super(sb);
 354         if (!err)
 355                 err = fat_flush_inodes(sb, dir, inode);
 356
 357         return err;
 358 }
 359
 360 /***** Make a directory */
 361 static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 362 {
 363         struct super_block *sb = dir->i_sb;
 364         struct fat_slot_info sinfo;
 365         struct inode *inode;
 366         unsigned char msdos_name[MSDOS_NAME];
 367         struct timespec ts;
 368         int err, is_hid, cluster;
 369
 370         lock_super(sb);
 371
 372         err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 373                                 msdos_name, &MSDOS_SB(sb)->options);
 374         if (err)
 375                 goto out;
 376         is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 377         /* foo vs .foo situation */
 378         if (!fat_scan(dir, msdos_name, &sinfo)) {
 379                 brelse(sinfo.bh);
 380                 err = -EINVAL;
 381                 goto out;
 382         }
 383
 384         ts = CURRENT_TIME_SEC;
 385         cluster = fat_alloc_new_dir(dir, &ts);
 386         if (cluster < 0) {
 387                 err = cluster;
 388                 goto out;
 389         }
 390         err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 391         if (err)
 392                 goto out_free;
 393         inc_nlink(dir);
 394
 395         inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 396         brelse(sinfo.bh);
 397         if (IS_ERR(inode)) {
 398                 err = PTR_ERR(inode);
 399                 /* the directory was completed, just return a error */
 400                 goto out;
 401         }
 402         inode->i_nlink = 2;
 403         inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 404         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 405
 406         d_instantiate(dentry, inode);
 407
 408         unlock_super(sb);
 409         fat_flush_inodes(sb, dir, inode);
 410         return 0;
 411
 412 out_free:
 413         fat_free_clusters(dir, cluster);
 414 out:
 415         unlock_super(sb);
 416         return err;
 417 }
 418
 419 /***** Unlink a file */
 420 static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 421 {
 422         struct inode *inode = dentry->d_inode;
 423         struct super_block *sb= inode->i_sb;
 424         struct fat_slot_info sinfo;
 425         int err;
 426
 427         lock_super(sb);
 428         err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 429         if (err)
 430                 goto out;
 431
 432         err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 433         if (err)
 434                 goto out;
 435         clear_nlink(inode);
 436         inode->i_ctime = CURRENT_TIME_SEC;
 437         fat_detach(inode);
 438 out:
 439         unlock_super(sb);
 440         if (!err)
 441                 err = fat_flush_inodes(sb, dir, inode);
 442
 443         return err;
 444 }
 445
 446 static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 447                            struct dentry *old_dentry,
 448                            struct inode *new_dir, unsigned char *new_name,
 449                            struct dentry *new_dentry, int is_hid)
 450 {
 451         struct buffer_head *dotdot_bh;
 452         struct msdos_dir_entry *dotdot_de;
 453         struct inode *old_inode, *new_inode;
 454         struct fat_slot_info old_sinfo, sinfo;
 455         struct timespec ts;
 456         loff_t dotdot_i_pos, new_i_pos;
 457         int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 458
 459         old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 460         old_inode = old_dentry->d_inode;
 461         new_inode = new_dentry->d_inode;
 462
 463         err = fat_scan(old_dir, old_name, &old_sinfo);
 464         if (err) {
 465                 err = -EIO;
 466                 goto out;
 467         }
 468
 469         is_dir = S_ISDIR(old_inode->i_mode);
 470         update_dotdot = (is_dir && old_dir != new_dir);
 471         if (update_dotdot) {
 472                 if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
 473                                          &dotdot_i_pos) < 0) {
 474                         err = -EIO;
 475                         goto out;
 476                 }
 477         }
 478
 479         old_attrs = MSDOS_I(old_inode)->i_attrs;
 480         err = fat_scan(new_dir, new_name, &sinfo);
 481         if (!err) {
 482                 if (!new_inode) {
 483                         /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 484                         if (sinfo.de != old_sinfo.de) {
 485                                 err = -EINVAL;
 486                                 goto out;
 487                         }
 488                         if (is_hid)
 489                                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 490                         else
 491                                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 492                         if (IS_DIRSYNC(old_dir)) {
 493                                 err = fat_sync_inode(old_inode);
 494                                 if (err) {
 495                                         MSDOS_I(old_inode)->i_attrs = old_attrs;
 496                                         goto out;
 497                                 }
 498                         } else
 499                                 mark_inode_dirty(old_inode);
 500
 501                         old_dir->i_version++;
 502                         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 503                         if (IS_DIRSYNC(old_dir))
 504                                 (void)fat_sync_inode(old_dir);
 505                         else
 506                                 mark_inode_dirty(old_dir);
 507                         goto out;
 508                 }
 509         }
 510
 511         ts = CURRENT_TIME_SEC;
 512         if (new_inode) {
 513                 if (err)
 514                         goto out;
 515                 if (is_dir) {
 516                         err = fat_dir_empty(new_inode);
 517                         if (err)
 518                                 goto out;
 519                 }
 520                 new_i_pos = MSDOS_I(new_inode)->i_pos;
 521                 fat_detach(new_inode);
 522         } else {
 523                 err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 524                                       &ts, &sinfo);
 525                 if (err)
 526                         goto out;
 527                 new_i_pos = sinfo.i_pos;
 528         }
 529         new_dir->i_version++;
 530
 531         fat_detach(old_inode);
 532         fat_attach(old_inode, new_i_pos);
 533         if (is_hid)
 534                 MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 535         else
 536                 MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 537         if (IS_DIRSYNC(new_dir)) {
 538                 err = fat_sync_inode(old_inode);
 539                 if (err)
 540                         goto error_inode;
 541         } else
 542                 mark_inode_dirty(old_inode);
 543
 544         if (update_dotdot) {
 545                 int start = MSDOS_I(new_dir)->i_logstart;
 546                 dotdot_de->start = cpu_to_le16(start);
 547                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 548                 mark_buffer_dirty(dotdot_bh);
 549                 if (IS_DIRSYNC(new_dir)) {
 550                         err = sync_dirty_buffer(dotdot_bh);
 551                         if (err)
 552                                 goto error_dotdot;
 553                 }
 554                 drop_nlink(old_dir);
 555                 if (!new_inode)
 556                         inc_nlink(new_dir);
 557         }
 558
 559         err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 560         old_sinfo.bh = NULL;
 561         if (err)
 562                 goto error_dotdot;
 563         old_dir->i_version++;
 564         old_dir->i_ctime = old_dir->i_mtime = ts;
 565         if (IS_DIRSYNC(old_dir))
 566                 (void)fat_sync_inode(old_dir);
 567         else
 568                 mark_inode_dirty(old_dir);
 569
 570         if (new_inode) {
 571                 drop_nlink(new_inode);
 572                 if (is_dir)
 573                         drop_nlink(new_inode);
 574                 new_inode->i_ctime = ts;
 575         }
 576 out:
 577         brelse(sinfo.bh);
 578         brelse(dotdot_bh);
 579         brelse(old_sinfo.bh);
 580         return err;
 581
 582 error_dotdot:
 583         /* data cluster is shared, serious corruption */
 584         corrupt = 1;
 585
 586         if (update_dotdot) {
 587                 int start = MSDOS_I(old_dir)->i_logstart;
 588                 dotdot_de->start = cpu_to_le16(start);
 589                 dotdot_de->starthi = cpu_to_le16(start >> 16);
 590                 mark_buffer_dirty(dotdot_bh);
 591                 corrupt |= sync_dirty_buffer(dotdot_bh);
 592         }
 593 error_inode:
 594         fat_detach(old_inode);
 595         fat_attach(old_inode, old_sinfo.i_pos);
 596         MSDOS_I(old_inode)->i_attrs = old_attrs;
 597         if (new_inode) {
 598                 fat_attach(new_inode, new_i_pos);
 599                 if (corrupt)
 600                         corrupt |= fat_sync_inode(new_inode);
 601         } else {
 602                 /*
 603                  * If new entry was not sharing the data cluster, it
 604                  * shouldn't be serious corruption.
 605                  */
 606                 int err2 = fat_remove_entries(new_dir, &sinfo);
 607                 if (corrupt)
 608                         corrupt |= err2;
 609                 sinfo.bh = NULL;
 610         }
 611         if (corrupt < 0) {
 612                 fat_fs_panic(new_dir->i_sb,
 613                              "%s: Filesystem corrupted (i_pos %lld)",
 614                              __FUNCTION__, sinfo.i_pos);
 615         }
 616         goto out;
 617 }
 618
 619 /***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 620 static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 621                         struct inode *new_dir, struct dentry *new_dentry)
 622 {
 623         struct super_block *sb = old_dir->i_sb;
 624         unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 625         int err, is_hid;
 626
 627         lock_super(sb);
 628
 629         err = msdos_format_name(old_dentry->d_name.name,
 630                                 old_dentry->d_name.len, old_msdos_name,
 631                                 &MSDOS_SB(old_dir->i_sb)->options);
 632         if (err)
 633                 goto out;
 634         err = msdos_format_name(new_dentry->d_name.name,
 635                                 new_dentry->d_name.len, new_msdos_name,
 636                                 &MSDOS_SB(new_dir->i_sb)->options);
 637         if (err)
 638                 goto out;
 639
 640         is_hid =
 641              (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 642
 643         err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 644                               new_dir, new_msdos_name, new_dentry, is_hid);
 645 out:
 646         unlock_super(sb);
 647         if (!err)
 648                 err = fat_flush_inodes(sb, old_dir, new_dir);
 649         return err;
 650 }
 651
 652 static const struct inode_operations msdos_dir_inode_operations = {
 653         .create         = msdos_create,
 654         .lookup         = msdos_lookup,
 655         .unlink         = msdos_unlink,
 656         .mkdir          = msdos_mkdir,
 657         .rmdir          = msdos_rmdir,
 658         .rename         = msdos_rename,
 659         .setattr        = fat_setattr,
 660         .getattr        = fat_getattr,
 661 };
 662
 663 static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 664 {
 665         int res;
 666
 667         res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
 668         if (res)
 669                 return res;
 670
 671         sb->s_flags |= MS_NOATIME;
 672         sb->s_root->d_op = &msdos_dentry_operations;
 673         return 0;
 674 }
 675
 676 static int msdos_get_sb(struct file_system_type *fs_type,
 677                         int flags, const char *dev_name,
 678                         void *data, struct vfsmount *mnt)
 679 {
 680         return get_sb_bdev(fs_type, flags, dev_name, data, msdos_fill_super,
 681                            mnt);
 682 }
 683
 684 static struct file_system_type msdos_fs_type = {
 685         .owner          = THIS_MODULE,
 686         .name           = "msdos",
 687         .get_sb         = msdos_get_sb,
 688         .kill_sb        = kill_block_super,
 689         .fs_flags       = FS_REQUIRES_DEV,
 690 };
 691
 692 static int __init init_msdos_fs(void)
 693 {
 694         return register_filesystem(&msdos_fs_type);
 695 }
 696
 697 static void __exit exit_msdos_fs(void)
 698 {
 699         unregister_filesystem(&msdos_fs_type);
 700 }
 701
 702 MODULE_LICENSE("GPL");
 703 MODULE_AUTHOR("Werner Almesberger");
 704 MODULE_DESCRIPTION("MS-DOS filesystem support");
 705
 706 module_init(init_msdos_fs)
 707 module_exit(exit_msdos_fs)