LXR linux/fs/fat/namei

   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 "fat.h"
  11
  12/* Characters that are undesirable in an MS-DOS file name */
  13static unsigned char bad_chars[] = "*?<>|\"";
  14static unsigned char bad_if_strict[] = "+=,; ";
  15
  16/***** Formats an MS-DOS file name. Rejects invalid names. */
  17static int msdos_format_name(const unsigned char *name, int len,
  18                             unsigned char *res, struct fat_mount_options *opts)
  19        /*
  20         * name is the proposed name, len is its length, res is
  21         * the resulting name, opts->name_check is either (r)elaxed,
  22         * (n)ormal or (s)trict, opts->dotsOK allows dots at the
  23         * beginning of name (for hidden files)
  24         */
  25{
  26        unsigned char *walk;
  27        unsigned char c;
  28        int space;
  29
  30        if (name[0] == '.') {   /* dotfile because . and .. already done */
  31                if (opts->dotsOK) {
  32                        /* Get rid of dot - test for it elsewhere */
  33                        name++;
  34                        len--;
  35                } else
  36                        return -EINVAL;
  37        }
  38        /*
  39         * disallow names that _really_ start with a dot
  40         */
  41        space = 1;
  42        c = 0;
  43        for (walk = res; len && walk - res < 8; walk++) {
  44                c = *name++;
  45                len--;
  46                if (opts->name_check != 'r' && strchr(bad_chars, c))
  47                        return -EINVAL;
  48                if (opts->name_check == 's' && strchr(bad_if_strict, c))
  49                        return -EINVAL;
  50                if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
  51                        return -EINVAL;
  52                if (c < ' ' || c == ':' || c == '\\')
  53                        return -EINVAL;
  54        /*
  55         * 0xE5 is legal as a first character, but we must substitute
  56         * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
  57         * does this.
  58         * It seems that Microsoft hacked DOS to support non-US
  59         * characters after the 0xE5 character was already in use to
  60         * mark deleted files.
  61         */
  62                if ((res == walk) && (c == 0xE5))
  63                        c = 0x05;
  64                if (c == '.')
  65                        break;
  66                space = (c == ' ');
  67                *walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
  68        }
  69        if (space)
  70                return -EINVAL;
  71        if (opts->name_check == 's' && len && c != '.') {
  72                c = *name++;
  73                len--;
  74                if (c != '.')
  75                        return -EINVAL;
  76        }
  77        while (c != '.' && len--)
  78                c = *name++;
  79        if (c == '.') {
  80                while (walk - res < 8)
  81                        *walk++ = ' ';
  82                while (len > 0 && walk - res < MSDOS_NAME) {
  83                        c = *name++;
  84                        len--;
  85                        if (opts->name_check != 'r' && strchr(bad_chars, c))
  86                                return -EINVAL;
  87                        if (opts->name_check == 's' &&
  88                            strchr(bad_if_strict, c))
  89                                return -EINVAL;
  90                        if (c < ' ' || c == ':' || c == '\\')
  91                                return -EINVAL;
  92                        if (c == '.') {
  93                                if (opts->name_check == 's')
  94                                        return -EINVAL;
  95                                break;
  96                        }
  97                        if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
  98                                return -EINVAL;
  99                        space = c == ' ';
 100                        if (!opts->nocase && c >= 'a' && c <= 'z')
 101                                *walk++ = c - 32;
 102                        else
 103                                *walk++ = c;
 104                }
 105                if (space)
 106                        return -EINVAL;
 107                if (opts->name_check == 's' && len)
 108                        return -EINVAL;
 109        }
 110        while (walk - res < MSDOS_NAME)
 111                *walk++ = ' ';
 112
 113        return 0;
 114}
 115
 116/***** Locates a directory entry.  Uses unformatted name. */
 117static int msdos_find(struct inode *dir, const unsigned char *name, int len,
 118                      struct fat_slot_info *sinfo)
 119{
 120        struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 121        unsigned char msdos_name[MSDOS_NAME];
 122        int err;
 123
 124        err = msdos_format_name(name, len, msdos_name, &sbi->options);
 125        if (err)
 126                return -ENOENT;
 127
 128        err = fat_scan(dir, msdos_name, sinfo);
 129        if (!err && sbi->options.dotsOK) {
 130                if (name[0] == '.') {
 131                        if (!(sinfo->de->attr & ATTR_HIDDEN))
 132                                err = -ENOENT;
 133                } else {
 134                        if (sinfo->de->attr & ATTR_HIDDEN)
 135                                err = -ENOENT;
 136                }
 137                if (err)
 138                        brelse(sinfo->bh);
 139        }
 140        return err;
 141}
 142
 143/*
 144 * Compute the hash for the msdos name corresponding to the dentry.
 145 * Note: if the name is invalid, we leave the hash code unchanged so
 146 * that the existing dentry can be used. The msdos fs routines will
 147 * return ENOENT or EINVAL as appropriate.
 148 */
 149static int msdos_hash(const struct dentry *dentry, struct qstr *qstr)
 150{
 151        struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 152        unsigned char msdos_name[MSDOS_NAME];
 153        int error;
 154
 155        error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
 156        if (!error)
 157                qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
 158        return 0;
 159}
 160
 161/*
 162 * Compare two msdos names. If either of the names are invalid,
 163 * we fall back to doing the standard name comparison.
 164 */
 165static int msdos_cmp(const struct dentry *parent, const struct dentry *dentry,
 166                unsigned int len, const char *str, const struct qstr *name)
 167{
 168        struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
 169        unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 170        int error;
 171
 172        error = msdos_format_name(name->name, name->len, a_msdos_name, options);
 173        if (error)
 174                goto old_compare;
 175        error = msdos_format_name(str, len, b_msdos_name, options);
 176        if (error)
 177                goto old_compare;
 178        error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
 179out:
 180        return error;
 181
 182old_compare:
 183        error = 1;
 184        if (name->len == len)
 185                error = memcmp(name->name, str, len);
 186        goto out;
 187}
 188
 189static const struct dentry_operations msdos_dentry_operations = {
 190        .d_hash         = msdos_hash,
 191        .d_compare      = msdos_cmp,
 192};
 193
 194/*
 195 * AV. Wrappers for FAT sb operations. Is it wise?
 196 */
 197
 198/***** Get inode using directory and name */
 199static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
 200                                   unsigned int flags)
 201{
 202        struct super_block *sb = dir->i_sb;
 203        struct fat_slot_info sinfo;
 204        struct inode *inode;
 205        int err;
 206
 207        mutex_lock(&MSDOS_SB(sb)->s_lock);
 208        err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 209        switch (err) {
 210        case -ENOENT:
 211                inode = NULL;
 212                break;
 213        case 0:
 214                inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 215                brelse(sinfo.bh);
 216                break;
 217        default:
 218                inode = ERR_PTR(err);
 219        }
 220        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 221        return d_splice_alias(inode, dentry);
 222}
 223
 224/***** Creates a directory entry (name is already formatted). */
 225static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 226                           int is_dir, int is_hid, int cluster,
 227                           struct timespec *ts, struct fat_slot_info *sinfo)
 228{
 229        struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
 230        struct msdos_dir_entry de;
 231        __le16 time, date;
 232        int err;
 233
 234        memcpy(de.name, name, MSDOS_NAME);
 235        de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
 236        if (is_hid)
 237                de.attr |= ATTR_HIDDEN;
 238        de.lcase = 0;
 239        fat_time_unix2fat(sbi, ts, &time, &date, NULL);
 240        de.cdate = de.adate = 0;
 241        de.ctime = 0;
 242        de.ctime_cs = 0;
 243        de.time = time;
 244        de.date = date;
 245        fat_set_start(&de, cluster);
 246        de.size = 0;
 247
 248        err = fat_add_entries(dir, &de, 1, sinfo);
 249        if (err)
 250                return err;
 251
 252        dir->i_ctime = dir->i_mtime = *ts;
 253        if (IS_DIRSYNC(dir))
 254                (void)fat_sync_inode(dir);
 255        else
 256                mark_inode_dirty(dir);
 257
 258        return 0;
 259}
 260
 261/***** Create a file */
 262static int msdos_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 263                        bool excl)
 264{
 265        struct super_block *sb = dir->i_sb;
 266        struct inode *inode = NULL;
 267        struct fat_slot_info sinfo;
 268        struct timespec ts;
 269        unsigned char msdos_name[MSDOS_NAME];
 270        int err, is_hid;
 271
 272        mutex_lock(&MSDOS_SB(sb)->s_lock);
 273
 274        err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 275                                msdos_name, &MSDOS_SB(sb)->options);
 276        if (err)
 277                goto out;
 278        is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 279        /* Have to do it due to foo vs. .foo conflicts */
 280        if (!fat_scan(dir, msdos_name, &sinfo)) {
 281                brelse(sinfo.bh);
 282                err = -EINVAL;
 283                goto out;
 284        }
 285
 286        ts = CURRENT_TIME_SEC;
 287        err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
 288        if (err)
 289                goto out;
 290        inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 291        brelse(sinfo.bh);
 292        if (IS_ERR(inode)) {
 293                err = PTR_ERR(inode);
 294                goto out;
 295        }
 296        inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 297        /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 298
 299        d_instantiate(dentry, inode);
 300out:
 301        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 302        if (!err)
 303                err = fat_flush_inodes(sb, dir, inode);
 304        return err;
 305}
 306
 307/***** Remove a directory */
 308static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 309{
 310        struct super_block *sb = dir->i_sb;
 311        struct inode *inode = d_inode(dentry);
 312        struct fat_slot_info sinfo;
 313        int err;
 314
 315        mutex_lock(&MSDOS_SB(sb)->s_lock);
 316        /*
 317         * Check whether the directory is not in use, then check
 318         * whether it is empty.
 319         */
 320        err = fat_dir_empty(inode);
 321        if (err)
 322                goto out;
 323        err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 324        if (err)
 325                goto out;
 326
 327        err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 328        if (err)
 329                goto out;
 330        drop_nlink(dir);
 331
 332        clear_nlink(inode);
 333        inode->i_ctime = CURRENT_TIME_SEC;
 334        fat_detach(inode);
 335out:
 336        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 337        if (!err)
 338                err = fat_flush_inodes(sb, dir, inode);
 339
 340        return err;
 341}
 342
 343/***** Make a directory */
 344static int msdos_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 345{
 346        struct super_block *sb = dir->i_sb;
 347        struct fat_slot_info sinfo;
 348        struct inode *inode;
 349        unsigned char msdos_name[MSDOS_NAME];
 350        struct timespec ts;
 351        int err, is_hid, cluster;
 352
 353        mutex_lock(&MSDOS_SB(sb)->s_lock);
 354
 355        err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
 356                                msdos_name, &MSDOS_SB(sb)->options);
 357        if (err)
 358                goto out;
 359        is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
 360        /* foo vs .foo situation */
 361        if (!fat_scan(dir, msdos_name, &sinfo)) {
 362                brelse(sinfo.bh);
 363                err = -EINVAL;
 364                goto out;
 365        }
 366
 367        ts = CURRENT_TIME_SEC;
 368        cluster = fat_alloc_new_dir(dir, &ts);
 369        if (cluster < 0) {
 370                err = cluster;
 371                goto out;
 372        }
 373        err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
 374        if (err)
 375                goto out_free;
 376        inc_nlink(dir);
 377
 378        inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
 379        brelse(sinfo.bh);
 380        if (IS_ERR(inode)) {
 381                err = PTR_ERR(inode);
 382                /* the directory was completed, just return a error */
 383                goto out;
 384        }
 385        set_nlink(inode, 2);
 386        inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
 387        /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 388
 389        d_instantiate(dentry, inode);
 390
 391        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 392        fat_flush_inodes(sb, dir, inode);
 393        return 0;
 394
 395out_free:
 396        fat_free_clusters(dir, cluster);
 397out:
 398        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 399        return err;
 400}
 401
 402/***** Unlink a file */
 403static int msdos_unlink(struct inode *dir, struct dentry *dentry)
 404{
 405        struct inode *inode = d_inode(dentry);
 406        struct super_block *sb = inode->i_sb;
 407        struct fat_slot_info sinfo;
 408        int err;
 409
 410        mutex_lock(&MSDOS_SB(sb)->s_lock);
 411        err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
 412        if (err)
 413                goto out;
 414
 415        err = fat_remove_entries(dir, &sinfo);  /* and releases bh */
 416        if (err)
 417                goto out;
 418        clear_nlink(inode);
 419        inode->i_ctime = CURRENT_TIME_SEC;
 420        fat_detach(inode);
 421out:
 422        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 423        if (!err)
 424                err = fat_flush_inodes(sb, dir, inode);
 425
 426        return err;
 427}
 428
 429static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 430                           struct dentry *old_dentry,
 431                           struct inode *new_dir, unsigned char *new_name,
 432                           struct dentry *new_dentry, int is_hid)
 433{
 434        struct buffer_head *dotdot_bh;
 435        struct msdos_dir_entry *dotdot_de;
 436        struct inode *old_inode, *new_inode;
 437        struct fat_slot_info old_sinfo, sinfo;
 438        struct timespec ts;
 439        loff_t new_i_pos;
 440        int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
 441
 442        old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 443        old_inode = d_inode(old_dentry);
 444        new_inode = d_inode(new_dentry);
 445
 446        err = fat_scan(old_dir, old_name, &old_sinfo);
 447        if (err) {
 448                err = -EIO;
 449                goto out;
 450        }
 451
 452        is_dir = S_ISDIR(old_inode->i_mode);
 453        update_dotdot = (is_dir && old_dir != new_dir);
 454        if (update_dotdot) {
 455                if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
 456                        err = -EIO;
 457                        goto out;
 458                }
 459        }
 460
 461        old_attrs = MSDOS_I(old_inode)->i_attrs;
 462        err = fat_scan(new_dir, new_name, &sinfo);
 463        if (!err) {
 464                if (!new_inode) {
 465                        /* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
 466                        if (sinfo.de != old_sinfo.de) {
 467                                err = -EINVAL;
 468                                goto out;
 469                        }
 470                        if (is_hid)
 471                                MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 472                        else
 473                                MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 474                        if (IS_DIRSYNC(old_dir)) {
 475                                err = fat_sync_inode(old_inode);
 476                                if (err) {
 477                                        MSDOS_I(old_inode)->i_attrs = old_attrs;
 478                                        goto out;
 479                                }
 480                        } else
 481                                mark_inode_dirty(old_inode);
 482
 483                        old_dir->i_version++;
 484                        old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 485                        if (IS_DIRSYNC(old_dir))
 486                                (void)fat_sync_inode(old_dir);
 487                        else
 488                                mark_inode_dirty(old_dir);
 489                        goto out;
 490                }
 491        }
 492
 493        ts = CURRENT_TIME_SEC;
 494        if (new_inode) {
 495                if (err)
 496                        goto out;
 497                if (is_dir) {
 498                        err = fat_dir_empty(new_inode);
 499                        if (err)
 500                                goto out;
 501                }
 502                new_i_pos = MSDOS_I(new_inode)->i_pos;
 503                fat_detach(new_inode);
 504        } else {
 505                err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
 506                                      &ts, &sinfo);
 507                if (err)
 508                        goto out;
 509                new_i_pos = sinfo.i_pos;
 510        }
 511        new_dir->i_version++;
 512
 513        fat_detach(old_inode);
 514        fat_attach(old_inode, new_i_pos);
 515        if (is_hid)
 516                MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
 517        else
 518                MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
 519        if (IS_DIRSYNC(new_dir)) {
 520                err = fat_sync_inode(old_inode);
 521                if (err)
 522                        goto error_inode;
 523        } else
 524                mark_inode_dirty(old_inode);
 525
 526        if (update_dotdot) {
 527                fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
 528                mark_buffer_dirty_inode(dotdot_bh, old_inode);
 529                if (IS_DIRSYNC(new_dir)) {
 530                        err = sync_dirty_buffer(dotdot_bh);
 531                        if (err)
 532                                goto error_dotdot;
 533                }
 534                drop_nlink(old_dir);
 535                if (!new_inode)
 536                        inc_nlink(new_dir);
 537        }
 538
 539        err = fat_remove_entries(old_dir, &old_sinfo);  /* and releases bh */
 540        old_sinfo.bh = NULL;
 541        if (err)
 542                goto error_dotdot;
 543        old_dir->i_version++;
 544        old_dir->i_ctime = old_dir->i_mtime = ts;
 545        if (IS_DIRSYNC(old_dir))
 546                (void)fat_sync_inode(old_dir);
 547        else
 548                mark_inode_dirty(old_dir);
 549
 550        if (new_inode) {
 551                drop_nlink(new_inode);
 552                if (is_dir)
 553                        drop_nlink(new_inode);
 554                new_inode->i_ctime = ts;
 555        }
 556out:
 557        brelse(sinfo.bh);
 558        brelse(dotdot_bh);
 559        brelse(old_sinfo.bh);
 560        return err;
 561
 562error_dotdot:
 563        /* data cluster is shared, serious corruption */
 564        corrupt = 1;
 565
 566        if (update_dotdot) {
 567                fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
 568                mark_buffer_dirty_inode(dotdot_bh, old_inode);
 569                corrupt |= sync_dirty_buffer(dotdot_bh);
 570        }
 571error_inode:
 572        fat_detach(old_inode);
 573        fat_attach(old_inode, old_sinfo.i_pos);
 574        MSDOS_I(old_inode)->i_attrs = old_attrs;
 575        if (new_inode) {
 576                fat_attach(new_inode, new_i_pos);
 577                if (corrupt)
 578                        corrupt |= fat_sync_inode(new_inode);
 579        } else {
 580                /*
 581                 * If new entry was not sharing the data cluster, it
 582                 * shouldn't be serious corruption.
 583                 */
 584                int err2 = fat_remove_entries(new_dir, &sinfo);
 585                if (corrupt)
 586                        corrupt |= err2;
 587                sinfo.bh = NULL;
 588        }
 589        if (corrupt < 0) {
 590                fat_fs_error(new_dir->i_sb,
 591                             "%s: Filesystem corrupted (i_pos %lld)",
 592                             __func__, sinfo.i_pos);
 593        }
 594        goto out;
 595}
 596
 597/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
 598static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
 599                        struct inode *new_dir, struct dentry *new_dentry)
 600{
 601        struct super_block *sb = old_dir->i_sb;
 602        unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
 603        int err, is_hid;
 604
 605        mutex_lock(&MSDOS_SB(sb)->s_lock);
 606
 607        err = msdos_format_name(old_dentry->d_name.name,
 608                                old_dentry->d_name.len, old_msdos_name,
 609                                &MSDOS_SB(old_dir->i_sb)->options);
 610        if (err)
 611                goto out;
 612        err = msdos_format_name(new_dentry->d_name.name,
 613                                new_dentry->d_name.len, new_msdos_name,
 614                                &MSDOS_SB(new_dir->i_sb)->options);
 615        if (err)
 616                goto out;
 617
 618        is_hid =
 619             (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
 620
 621        err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
 622                              new_dir, new_msdos_name, new_dentry, is_hid);
 623out:
 624        mutex_unlock(&MSDOS_SB(sb)->s_lock);
 625        if (!err)
 626                err = fat_flush_inodes(sb, old_dir, new_dir);
 627        return err;
 628}
 629
 630static const struct inode_operations msdos_dir_inode_operations = {
 631        .create         = msdos_create,
 632        .lookup         = msdos_lookup,
 633        .unlink         = msdos_unlink,
 634        .mkdir          = msdos_mkdir,
 635        .rmdir          = msdos_rmdir,
 636        .rename         = msdos_rename,
 637        .setattr        = fat_setattr,
 638        .getattr        = fat_getattr,
 639};
 640
 641static void setup(struct super_block *sb)
 642{
 643        MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
 644        sb->s_d_op = &msdos_dentry_operations;
 645        sb->s_flags |= MS_NOATIME;
 646}
 647
 648static int msdos_fill_super(struct super_block *sb, void *data, int silent)
 649{
 650        return fat_fill_super(sb, data, silent, 0, setup);
 651}
 652
 653static struct dentry *msdos_mount(struct file_system_type *fs_type,
 654                        int flags, const char *dev_name,
 655                        void *data)
 656{
 657        return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
 658}
 659
 660static struct file_system_type msdos_fs_type = {
 661        .owner          = THIS_MODULE,
 662        .name           = "msdos",
 663        .mount          = msdos_mount,
 664        .kill_sb        = kill_block_super,
 665        .fs_flags       = FS_REQUIRES_DEV,
 666};
 667MODULE_ALIAS_FS("msdos");
 668
 669static int __init init_msdos_fs(void)
 670{
 671        return register_filesystem(&msdos_fs_type);
 672}
 673
 674static void __exit exit_msdos_fs(void)
 675{
 676        unregister_filesystem(&msdos_fs_type);
 677}
 678
 679MODULE_LICENSE("GPL");
 680MODULE_AUTHOR("Werner Almesberger");
 681MODULE_DESCRIPTION("MS-DOS filesystem support");
 682
 683module_init(init_msdos_fs)
 684module_exit(exit_msdos_fs)
 685