kernel/fs/fat/inode.c

   1 /*
   2  *  linux/fs/fat/inode.c
   3  *
   4  *  Written 1992,1993 by Werner Almesberger
   5  *  VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
   6  *  Rewritten for the constant inumbers support by Al Viro
   7  *
   8  *  Fixes:
   9  *
  10  *      Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/mpage.h>
  16 #include <linux/vfs.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/parser.h>
  19 #include <linux/uio.h>
  20 #include <linux/blkdev.h>
  21 #include <asm/unaligned.h>
  22 #include "fat.h"
  23
  24 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
  25 /* if user don't select VFAT, this is undefined. */
  26 #define CONFIG_FAT_DEFAULT_IOCHARSET    ""
  27 #endif
  28
  29 #define KB_IN_SECTORS 2
  30
  31 /*
  32  * A deserialized copy of the on-disk structure laid out in struct
  33  * fat_boot_sector.
  34  */
  35 struct fat_bios_param_block {
  36         u16     fat_sector_size;
  37         u8      fat_sec_per_clus;
  38         u16     fat_reserved;
  39         u8      fat_fats;
  40         u16     fat_dir_entries;
  41         u16     fat_sectors;
  42         u16     fat_fat_length;
  43         u32     fat_total_sect;
  44
  45         u8      fat16_state;
  46         u32     fat16_vol_id;
  47
  48         u32     fat32_length;
  49         u32     fat32_root_cluster;
  50         u16     fat32_info_sector;
  51         u8      fat32_state;
  52         u32     fat32_vol_id;
  53 };
  54
  55 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
  56 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
  57
  58 static struct fat_floppy_defaults {
  59         unsigned nr_sectors;
  60         unsigned sec_per_clus;
  61         unsigned dir_entries;
  62         unsigned media;
  63         unsigned fat_length;
  64 } floppy_defaults[] = {
  65 {
  66         .nr_sectors = 160 * KB_IN_SECTORS,
  67         .sec_per_clus = 1,
  68         .dir_entries = 64,
  69         .media = 0xFE,
  70         .fat_length = 1,
  71 },
  72 {
  73         .nr_sectors = 180 * KB_IN_SECTORS,
  74         .sec_per_clus = 1,
  75         .dir_entries = 64,
  76         .media = 0xFC,
  77         .fat_length = 2,
  78 },
  79 {
  80         .nr_sectors = 320 * KB_IN_SECTORS,
  81         .sec_per_clus = 2,
  82         .dir_entries = 112,
  83         .media = 0xFF,
  84         .fat_length = 1,
  85 },
  86 {
  87         .nr_sectors = 360 * KB_IN_SECTORS,
  88         .sec_per_clus = 2,
  89         .dir_entries = 112,
  90         .media = 0xFD,
  91         .fat_length = 2,
  92 },
  93 };
  94
  95 static int fat_add_cluster(struct inode *inode)
  96 {
  97         int err, cluster;
  98
  99         err = fat_alloc_clusters(inode, &cluster, 1);
 100         if (err)
 101                 return err;
 102         /* FIXME: this cluster should be added after data of this
 103          * cluster is writed */
 104         err = fat_chain_add(inode, cluster, 1);
 105         if (err)
 106                 fat_free_clusters(inode, cluster);
 107         return err;
 108 }
 109
 110 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
 111                                   unsigned long *max_blocks,
 112                                   struct buffer_head *bh_result, int create)
 113 {
 114         struct super_block *sb = inode->i_sb;
 115         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 116         unsigned long mapped_blocks;
 117         sector_t phys;
 118         int err, offset;
 119
 120         err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
 121         if (err)
 122                 return err;
 123         if (phys) {
 124                 map_bh(bh_result, sb, phys);
 125                 *max_blocks = min(mapped_blocks, *max_blocks);
 126                 return 0;
 127         }
 128         if (!create)
 129                 return 0;
 130
 131         if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
 132                 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
 133                         MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
 134                 return -EIO;
 135         }
 136
 137         offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
 138         if (!offset) {
 139                 /* TODO: multiple cluster allocation would be desirable. */
 140                 err = fat_add_cluster(inode);
 141                 if (err)
 142                         return err;
 143         }
 144         /* available blocks on this cluster */
 145         mapped_blocks = sbi->sec_per_clus - offset;
 146
 147         *max_blocks = min(mapped_blocks, *max_blocks);
 148         MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
 149
 150         err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
 151         if (err)
 152                 return err;
 153
 154         BUG_ON(!phys);
 155         BUG_ON(*max_blocks != mapped_blocks);
 156         set_buffer_new(bh_result);
 157         map_bh(bh_result, sb, phys);
 158
 159         return 0;
 160 }
 161
 162 static int fat_get_block(struct inode *inode, sector_t iblock,
 163                          struct buffer_head *bh_result, int create)
 164 {
 165         struct super_block *sb = inode->i_sb;
 166         unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 167         int err;
 168
 169         err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
 170         if (err)
 171                 return err;
 172         bh_result->b_size = max_blocks << sb->s_blocksize_bits;
 173         return 0;
 174 }
 175
 176 static int fat_writepage(struct page *page, struct writeback_control *wbc)
 177 {
 178         return block_write_full_page(page, fat_get_block, wbc);
 179 }
 180
 181 static int fat_writepages(struct address_space *mapping,
 182                           struct writeback_control *wbc)
 183 {
 184         return mpage_writepages(mapping, wbc, fat_get_block);
 185 }
 186
 187 static int fat_readpage(struct file *file, struct page *page)
 188 {
 189         return mpage_readpage(page, fat_get_block);
 190 }
 191
 192 static int fat_readpages(struct file *file, struct address_space *mapping,
 193                          struct list_head *pages, unsigned nr_pages)
 194 {
 195         return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
 196 }
 197
 198 static void fat_write_failed(struct address_space *mapping, loff_t to)
 199 {
 200         struct inode *inode = mapping->host;
 201
 202         if (to > inode->i_size) {
 203                 truncate_pagecache(inode, inode->i_size);
 204                 fat_truncate_blocks(inode, inode->i_size);
 205         }
 206 }
 207
 208 static int fat_write_begin(struct file *file, struct address_space *mapping,
 209                         loff_t pos, unsigned len, unsigned flags,
 210                         struct page **pagep, void **fsdata)
 211 {
 212         int err;
 213
 214         *pagep = NULL;
 215         err = cont_write_begin(file, mapping, pos, len, flags,
 216                                 pagep, fsdata, fat_get_block,
 217                                 &MSDOS_I(mapping->host)->mmu_private);
 218         if (err < 0)
 219                 fat_write_failed(mapping, pos + len);
 220         return err;
 221 }
 222
 223 static int fat_write_end(struct file *file, struct address_space *mapping,
 224                         loff_t pos, unsigned len, unsigned copied,
 225                         struct page *pagep, void *fsdata)
 226 {
 227         struct inode *inode = mapping->host;
 228         int err;
 229         err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
 230         if (err < len)
 231                 fat_write_failed(mapping, pos + len);
 232         if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
 233                 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 234                 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
 235                 mark_inode_dirty(inode);
 236         }
 237         return err;
 238 }
 239
 240 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 241                              loff_t offset)
 242 {
 243         struct file *file = iocb->ki_filp;
 244         struct address_space *mapping = file->f_mapping;
 245         struct inode *inode = mapping->host;
 246         size_t count = iov_iter_count(iter);
 247         ssize_t ret;
 248
 249         if (iov_iter_rw(iter) == WRITE) {
 250                 /*
 251                  * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
 252                  * so we need to update the ->mmu_private to block boundary.
 253                  *
 254                  * But we must fill the remaining area or hole by nul for
 255                  * updating ->mmu_private.
 256                  *
 257                  * Return 0, and fallback to normal buffered write.
 258                  */
 259                 loff_t size = offset + count;
 260                 if (MSDOS_I(inode)->mmu_private < size)
 261                         return 0;
 262         }
 263
 264         /*
 265          * FAT need to use the DIO_LOCKING for avoiding the race
 266          * condition of fat_get_block() and ->truncate().
 267          */
 268         ret = blockdev_direct_IO(iocb, inode, iter, offset, fat_get_block);
 269         if (ret < 0 && iov_iter_rw(iter) == WRITE)
 270                 fat_write_failed(mapping, offset + count);
 271
 272         return ret;
 273 }
 274
 275 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
 276 {
 277         sector_t blocknr;
 278
 279         /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
 280         down_read(&MSDOS_I(mapping->host)->truncate_lock);
 281         blocknr = generic_block_bmap(mapping, block, fat_get_block);
 282         up_read(&MSDOS_I(mapping->host)->truncate_lock);
 283
 284         return blocknr;
 285 }
 286
 287 /*
 288  * fat_block_truncate_page() zeroes out a mapping from file offset `from'
 289  * up to the end of the block which corresponds to `from'.
 290  * This is required during truncate to physically zeroout the tail end
 291  * of that block so it doesn't yield old data if the file is later grown.
 292  * Also, avoid causing failure from fsx for cases of "data past EOF"
 293  */
 294 int fat_block_truncate_page(struct inode *inode, loff_t from)
 295 {
 296         return block_truncate_page(inode->i_mapping, from, fat_get_block);
 297 }
 298
 299 static const struct address_space_operations fat_aops = {
 300         .readpage       = fat_readpage,
 301         .readpages      = fat_readpages,
 302         .writepage      = fat_writepage,
 303         .writepages     = fat_writepages,
 304         .write_begin    = fat_write_begin,
 305         .write_end      = fat_write_end,
 306         .direct_IO      = fat_direct_IO,
 307         .bmap           = _fat_bmap
 308 };
 309
 310 /*
 311  * New FAT inode stuff. We do the following:
 312  *      a) i_ino is constant and has nothing with on-disk location.
 313  *      b) FAT manages its own cache of directory entries.
 314  *      c) *This* cache is indexed by on-disk location.
 315  *      d) inode has an associated directory entry, all right, but
 316  *              it may be unhashed.
 317  *      e) currently entries are stored within struct inode. That should
 318  *              change.
 319  *      f) we deal with races in the following way:
 320  *              1. readdir() and lookup() do FAT-dir-cache lookup.
 321  *              2. rename() unhashes the F-d-c entry and rehashes it in
 322  *                      a new place.
 323  *              3. unlink() and rmdir() unhash F-d-c entry.
 324  *              4. fat_write_inode() checks whether the thing is unhashed.
 325  *                      If it is we silently return. If it isn't we do bread(),
 326  *                      check if the location is still valid and retry if it
 327  *                      isn't. Otherwise we do changes.
 328  *              5. Spinlock is used to protect hash/unhash/location check/lookup
 329  *              6. fat_evict_inode() unhashes the F-d-c entry.
 330  *              7. lookup() and readdir() do igrab() if they find a F-d-c entry
 331  *                      and consider negative result as cache miss.
 332  */
 333
 334 static void fat_hash_init(struct super_block *sb)
 335 {
 336         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 337         int i;
 338
 339         spin_lock_init(&sbi->inode_hash_lock);
 340         for (i = 0; i < FAT_HASH_SIZE; i++)
 341                 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
 342 }
 343
 344 static inline unsigned long fat_hash(loff_t i_pos)
 345 {
 346         return hash_32(i_pos, FAT_HASH_BITS);
 347 }
 348
 349 static void dir_hash_init(struct super_block *sb)
 350 {
 351         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 352         int i;
 353
 354         spin_lock_init(&sbi->dir_hash_lock);
 355         for (i = 0; i < FAT_HASH_SIZE; i++)
 356                 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
 357 }
 358
 359 void fat_attach(struct inode *inode, loff_t i_pos)
 360 {
 361         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 362
 363         if (inode->i_ino != MSDOS_ROOT_INO) {
 364                 struct hlist_head *head =   sbi->inode_hashtable
 365                                           + fat_hash(i_pos);
 366
 367                 spin_lock(&sbi->inode_hash_lock);
 368                 MSDOS_I(inode)->i_pos = i_pos;
 369                 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
 370                 spin_unlock(&sbi->inode_hash_lock);
 371         }
 372
 373         /* If NFS support is enabled, cache the mapping of start cluster
 374          * to directory inode. This is used during reconnection of
 375          * dentries to the filesystem root.
 376          */
 377         if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
 378                 struct hlist_head *d_head = sbi->dir_hashtable;
 379                 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
 380
 381                 spin_lock(&sbi->dir_hash_lock);
 382                 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
 383                 spin_unlock(&sbi->dir_hash_lock);
 384         }
 385 }
 386 EXPORT_SYMBOL_GPL(fat_attach);
 387
 388 void fat_detach(struct inode *inode)
 389 {
 390         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 391         spin_lock(&sbi->inode_hash_lock);
 392         MSDOS_I(inode)->i_pos = 0;
 393         hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
 394         spin_unlock(&sbi->inode_hash_lock);
 395
 396         if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
 397                 spin_lock(&sbi->dir_hash_lock);
 398                 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
 399                 spin_unlock(&sbi->dir_hash_lock);
 400         }
 401 }
 402 EXPORT_SYMBOL_GPL(fat_detach);
 403
 404 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
 405 {
 406         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 407         struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
 408         struct msdos_inode_info *i;
 409         struct inode *inode = NULL;
 410
 411         spin_lock(&sbi->inode_hash_lock);
 412         hlist_for_each_entry(i, head, i_fat_hash) {
 413                 BUG_ON(i->vfs_inode.i_sb != sb);
 414                 if (i->i_pos != i_pos)
 415                         continue;
 416                 inode = igrab(&i->vfs_inode);
 417                 if (inode)
 418                         break;
 419         }
 420         spin_unlock(&sbi->inode_hash_lock);
 421         return inode;
 422 }
 423
 424 static int is_exec(unsigned char *extension)
 425 {
 426         unsigned char exe_extensions[] = "EXECOMBAT", *walk;
 427
 428         for (walk = exe_extensions; *walk; walk += 3)
 429                 if (!strncmp(extension, walk, 3))
 430                         return 1;
 431         return 0;
 432 }
 433
 434 static int fat_calc_dir_size(struct inode *inode)
 435 {
 436         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 437         int ret, fclus, dclus;
 438
 439         inode->i_size = 0;
 440         if (MSDOS_I(inode)->i_start == 0)
 441                 return 0;
 442
 443         ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
 444         if (ret < 0)
 445                 return ret;
 446         inode->i_size = (fclus + 1) << sbi->cluster_bits;
 447
 448         return 0;
 449 }
 450
 451 /* doesn't deal with root inode */
 452 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 453 {
 454         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 455         int error;
 456
 457         MSDOS_I(inode)->i_pos = 0;
 458         inode->i_uid = sbi->options.fs_uid;
 459         inode->i_gid = sbi->options.fs_gid;
 460         inode->i_version++;
 461         inode->i_generation = get_seconds();
 462
 463         if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
 464                 inode->i_generation &= ~1;
 465                 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
 466                 inode->i_op = sbi->dir_ops;
 467                 inode->i_fop = &fat_dir_operations;
 468
 469                 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
 470                 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
 471                 error = fat_calc_dir_size(inode);
 472                 if (error < 0)
 473                         return error;
 474                 MSDOS_I(inode)->mmu_private = inode->i_size;
 475
 476                 set_nlink(inode, fat_subdirs(inode));
 477         } else { /* not a directory */
 478                 inode->i_generation |= 1;
 479                 inode->i_mode = fat_make_mode(sbi, de->attr,
 480                         ((sbi->options.showexec && !is_exec(de->name + 8))
 481                          ? S_IRUGO|S_IWUGO : S_IRWXUGO));
 482                 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
 483
 484                 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
 485                 inode->i_size = le32_to_cpu(de->size);
 486                 inode->i_op = &fat_file_inode_operations;
 487                 inode->i_fop = &fat_file_operations;
 488                 inode->i_mapping->a_ops = &fat_aops;
 489                 MSDOS_I(inode)->mmu_private = inode->i_size;
 490         }
 491         if (de->attr & ATTR_SYS) {
 492                 if (sbi->options.sys_immutable)
 493                         inode->i_flags |= S_IMMUTABLE;
 494         }
 495         fat_save_attrs(inode, de->attr);
 496
 497         inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
 498                            & ~((loff_t)sbi->cluster_size - 1)) >> 9;
 499
 500         fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
 501         if (sbi->options.isvfat) {
 502                 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
 503                                   de->cdate, de->ctime_cs);
 504                 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
 505         } else
 506                 inode->i_ctime = inode->i_atime = inode->i_mtime;
 507
 508         return 0;
 509 }
 510
 511 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
 512 {
 513         if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
 514                 mutex_lock(&sbi->nfs_build_inode_lock);
 515 }
 516
 517 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
 518 {
 519         if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
 520                 mutex_unlock(&sbi->nfs_build_inode_lock);
 521 }
 522
 523 struct inode *fat_build_inode(struct super_block *sb,
 524                         struct msdos_dir_entry *de, loff_t i_pos)
 525 {
 526         struct inode *inode;
 527         int err;
 528
 529         fat_lock_build_inode(MSDOS_SB(sb));
 530         inode = fat_iget(sb, i_pos);
 531         if (inode)
 532                 goto out;
 533         inode = new_inode(sb);
 534         if (!inode) {
 535                 inode = ERR_PTR(-ENOMEM);
 536                 goto out;
 537         }
 538         inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
 539         inode->i_version = 1;
 540         err = fat_fill_inode(inode, de);
 541         if (err) {
 542                 iput(inode);
 543                 inode = ERR_PTR(err);
 544                 goto out;
 545         }
 546         fat_attach(inode, i_pos);
 547         insert_inode_hash(inode);
 548 out:
 549         fat_unlock_build_inode(MSDOS_SB(sb));
 550         return inode;
 551 }
 552
 553 EXPORT_SYMBOL_GPL(fat_build_inode);
 554
 555 static void fat_evict_inode(struct inode *inode)
 556 {
 557         truncate_inode_pages_final(&inode->i_data);
 558         if (!inode->i_nlink) {
 559                 inode->i_size = 0;
 560                 fat_truncate_blocks(inode, 0);
 561         }
 562         invalidate_inode_buffers(inode);
 563         clear_inode(inode);
 564         fat_cache_inval_inode(inode);
 565         fat_detach(inode);
 566 }
 567
 568 static void fat_set_state(struct super_block *sb,
 569                         unsigned int set, unsigned int force)
 570 {
 571         struct buffer_head *bh;
 572         struct fat_boot_sector *b;
 573         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 574
 575         /* do not change any thing if mounted read only */
 576         if ((sb->s_flags & MS_RDONLY) && !force)
 577                 return;
 578
 579         /* do not change state if fs was dirty */
 580         if (sbi->dirty) {
 581                 /* warn only on set (mount). */
 582                 if (set)
 583                         fat_msg(sb, KERN_WARNING, "Volume was not properly "
 584                                 "unmounted. Some data may be corrupt. "
 585                                 "Please run fsck.");
 586                 return;
 587         }
 588
 589         bh = sb_bread(sb, 0);
 590         if (bh == NULL) {
 591                 fat_msg(sb, KERN_ERR, "unable to read boot sector "
 592                         "to mark fs as dirty");
 593                 return;
 594         }
 595
 596         b = (struct fat_boot_sector *) bh->b_data;
 597
 598         if (sbi->fat_bits == 32) {
 599                 if (set)
 600                         b->fat32.state |= FAT_STATE_DIRTY;
 601                 else
 602                         b->fat32.state &= ~FAT_STATE_DIRTY;
 603         } else /* fat 16 and 12 */ {
 604                 if (set)
 605                         b->fat16.state |= FAT_STATE_DIRTY;
 606                 else
 607                         b->fat16.state &= ~FAT_STATE_DIRTY;
 608         }
 609
 610         mark_buffer_dirty(bh);
 611         sync_dirty_buffer(bh);
 612         brelse(bh);
 613 }
 614
 615 static void delayed_free(struct rcu_head *p)
 616 {
 617         struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
 618         unload_nls(sbi->nls_disk);
 619         unload_nls(sbi->nls_io);
 620         if (sbi->options.iocharset != fat_default_iocharset)
 621                 kfree(sbi->options.iocharset);
 622         kfree(sbi);
 623 }
 624
 625 static void fat_put_super(struct super_block *sb)
 626 {
 627         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 628
 629         fat_set_state(sb, 0, 0);
 630
 631         iput(sbi->fsinfo_inode);
 632         iput(sbi->fat_inode);
 633
 634         call_rcu(&sbi->rcu, delayed_free);
 635 }
 636
 637 static struct kmem_cache *fat_inode_cachep;
 638
 639 static struct inode *fat_alloc_inode(struct super_block *sb)
 640 {
 641         struct msdos_inode_info *ei;
 642         ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
 643         if (!ei)
 644                 return NULL;
 645
 646         init_rwsem(&ei->truncate_lock);
 647         return &ei->vfs_inode;
 648 }
 649
 650 static void fat_i_callback(struct rcu_head *head)
 651 {
 652         struct inode *inode = container_of(head, struct inode, i_rcu);
 653         kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
 654 }
 655
 656 static void fat_destroy_inode(struct inode *inode)
 657 {
 658         call_rcu(&inode->i_rcu, fat_i_callback);
 659 }
 660
 661 static void init_once(void *foo)
 662 {
 663         struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
 664
 665         spin_lock_init(&ei->cache_lru_lock);
 666         ei->nr_caches = 0;
 667         ei->cache_valid_id = FAT_CACHE_VALID + 1;
 668         INIT_LIST_HEAD(&ei->cache_lru);
 669         INIT_HLIST_NODE(&ei->i_fat_hash);
 670         INIT_HLIST_NODE(&ei->i_dir_hash);
 671         inode_init_once(&ei->vfs_inode);
 672 }
 673
 674 static int __init fat_init_inodecache(void)
 675 {
 676         fat_inode_cachep = kmem_cache_create("fat_inode_cache",
 677                                              sizeof(struct msdos_inode_info),
 678                                              0, (SLAB_RECLAIM_ACCOUNT|
 679                                                 SLAB_MEM_SPREAD),
 680                                              init_once);
 681         if (fat_inode_cachep == NULL)
 682                 return -ENOMEM;
 683         return 0;
 684 }
 685
 686 static void __exit fat_destroy_inodecache(void)
 687 {
 688         /*
 689          * Make sure all delayed rcu free inodes are flushed before we
 690          * destroy cache.
 691          */
 692         rcu_barrier();
 693         kmem_cache_destroy(fat_inode_cachep);
 694 }
 695
 696 static int fat_remount(struct super_block *sb, int *flags, char *data)
 697 {
 698         int new_rdonly;
 699         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 700         *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
 701
 702         sync_filesystem(sb);
 703
 704         /* make sure we update state on remount. */
 705         new_rdonly = *flags & MS_RDONLY;
 706         if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
 707                 if (new_rdonly)
 708                         fat_set_state(sb, 0, 0);
 709                 else
 710                         fat_set_state(sb, 1, 1);
 711         }
 712         return 0;
 713 }
 714
 715 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
 716 {
 717         struct super_block *sb = dentry->d_sb;
 718         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 719         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 720
 721         /* If the count of free cluster is still unknown, counts it here. */
 722         if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
 723                 int err = fat_count_free_clusters(dentry->d_sb);
 724                 if (err)
 725                         return err;
 726         }
 727
 728         buf->f_type = dentry->d_sb->s_magic;
 729         buf->f_bsize = sbi->cluster_size;
 730         buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
 731         buf->f_bfree = sbi->free_clusters;
 732         buf->f_bavail = sbi->free_clusters;
 733         buf->f_fsid.val[0] = (u32)id;
 734         buf->f_fsid.val[1] = (u32)(id >> 32);
 735         buf->f_namelen =
 736                 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
 737
 738         return 0;
 739 }
 740
 741 static int __fat_write_inode(struct inode *inode, int wait)
 742 {
 743         struct super_block *sb = inode->i_sb;
 744         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 745         struct buffer_head *bh;
 746         struct msdos_dir_entry *raw_entry;
 747         loff_t i_pos;
 748         sector_t blocknr;
 749         int err, offset;
 750
 751         if (inode->i_ino == MSDOS_ROOT_INO)
 752                 return 0;
 753
 754 retry:
 755         i_pos = fat_i_pos_read(sbi, inode);
 756         if (!i_pos)
 757                 return 0;
 758
 759         fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
 760         bh = sb_bread(sb, blocknr);
 761         if (!bh) {
 762                 fat_msg(sb, KERN_ERR, "unable to read inode block "
 763                        "for updating (i_pos %lld)", i_pos);
 764                 return -EIO;
 765         }
 766         spin_lock(&sbi->inode_hash_lock);
 767         if (i_pos != MSDOS_I(inode)->i_pos) {
 768                 spin_unlock(&sbi->inode_hash_lock);
 769                 brelse(bh);
 770                 goto retry;
 771         }
 772
 773         raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
 774         if (S_ISDIR(inode->i_mode))
 775                 raw_entry->size = 0;
 776         else
 777                 raw_entry->size = cpu_to_le32(inode->i_size);
 778         raw_entry->attr = fat_make_attrs(inode);
 779         fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
 780         fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
 781                           &raw_entry->date, NULL);
 782         if (sbi->options.isvfat) {
 783                 __le16 atime;
 784                 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
 785                                   &raw_entry->cdate, &raw_entry->ctime_cs);
 786                 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
 787                                   &raw_entry->adate, NULL);
 788         }
 789         spin_unlock(&sbi->inode_hash_lock);
 790         mark_buffer_dirty(bh);
 791         err = 0;
 792         if (wait)
 793                 err = sync_dirty_buffer(bh);
 794         brelse(bh);
 795         return err;
 796 }
 797
 798 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
 799 {
 800         int err;
 801
 802         if (inode->i_ino == MSDOS_FSINFO_INO) {
 803                 struct super_block *sb = inode->i_sb;
 804
 805                 mutex_lock(&MSDOS_SB(sb)->s_lock);
 806                 err = fat_clusters_flush(sb);
 807                 mutex_unlock(&MSDOS_SB(sb)->s_lock);
 808         } else
 809                 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 810
 811         return err;
 812 }
 813
 814 int fat_sync_inode(struct inode *inode)
 815 {
 816         return __fat_write_inode(inode, 1);
 817 }
 818
 819 EXPORT_SYMBOL_GPL(fat_sync_inode);
 820
 821 static int fat_show_options(struct seq_file *m, struct dentry *root);
 822 static const struct super_operations fat_sops = {
 823         .alloc_inode    = fat_alloc_inode,
 824         .destroy_inode  = fat_destroy_inode,
 825         .write_inode    = fat_write_inode,
 826         .evict_inode    = fat_evict_inode,
 827         .put_super      = fat_put_super,
 828         .statfs         = fat_statfs,
 829         .remount_fs     = fat_remount,
 830
 831         .show_options   = fat_show_options,
 832 };
 833
 834 static int fat_show_options(struct seq_file *m, struct dentry *root)
 835 {
 836         struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
 837         struct fat_mount_options *opts = &sbi->options;
 838         int isvfat = opts->isvfat;
 839
 840         if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
 841                 seq_printf(m, ",uid=%u",
 842                                 from_kuid_munged(&init_user_ns, opts->fs_uid));
 843         if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
 844                 seq_printf(m, ",gid=%u",
 845                                 from_kgid_munged(&init_user_ns, opts->fs_gid));
 846         seq_printf(m, ",fmask=%04o", opts->fs_fmask);
 847         seq_printf(m, ",dmask=%04o", opts->fs_dmask);
 848         if (opts->allow_utime)
 849                 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
 850         if (sbi->nls_disk)
 851                 /* strip "cp" prefix from displayed option */
 852                 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
 853         if (isvfat) {
 854                 if (sbi->nls_io)
 855                         seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
 856
 857                 switch (opts->shortname) {
 858                 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
 859                         seq_puts(m, ",shortname=win95");
 860                         break;
 861                 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
 862                         seq_puts(m, ",shortname=winnt");
 863                         break;
 864                 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
 865                         seq_puts(m, ",shortname=mixed");
 866                         break;
 867                 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
 868                         seq_puts(m, ",shortname=lower");
 869                         break;
 870                 default:
 871                         seq_puts(m, ",shortname=unknown");
 872                         break;
 873                 }
 874         }
 875         if (opts->name_check != 'n')
 876                 seq_printf(m, ",check=%c", opts->name_check);
 877         if (opts->usefree)
 878                 seq_puts(m, ",usefree");
 879         if (opts->quiet)
 880                 seq_puts(m, ",quiet");
 881         if (opts->showexec)
 882                 seq_puts(m, ",showexec");
 883         if (opts->sys_immutable)
 884                 seq_puts(m, ",sys_immutable");
 885         if (!isvfat) {
 886                 if (opts->dotsOK)
 887                         seq_puts(m, ",dotsOK=yes");
 888                 if (opts->nocase)
 889                         seq_puts(m, ",nocase");
 890         } else {
 891                 if (opts->utf8)
 892                         seq_puts(m, ",utf8");
 893                 if (opts->unicode_xlate)
 894                         seq_puts(m, ",uni_xlate");
 895                 if (!opts->numtail)
 896                         seq_puts(m, ",nonumtail");
 897                 if (opts->rodir)
 898                         seq_puts(m, ",rodir");
 899         }
 900         if (opts->flush)
 901                 seq_puts(m, ",flush");
 902         if (opts->tz_set) {
 903                 if (opts->time_offset)
 904                         seq_printf(m, ",time_offset=%d", opts->time_offset);
 905                 else
 906                         seq_puts(m, ",tz=UTC");
 907         }
 908         if (opts->errors == FAT_ERRORS_CONT)
 909                 seq_puts(m, ",errors=continue");
 910         else if (opts->errors == FAT_ERRORS_PANIC)
 911                 seq_puts(m, ",errors=panic");
 912         else
 913                 seq_puts(m, ",errors=remount-ro");
 914         if (opts->nfs == FAT_NFS_NOSTALE_RO)
 915                 seq_puts(m, ",nfs=nostale_ro");
 916         else if (opts->nfs)
 917                 seq_puts(m, ",nfs=stale_rw");
 918         if (opts->discard)
 919                 seq_puts(m, ",discard");
 920         if (opts->dos1xfloppy)
 921                 seq_puts(m, ",dos1xfloppy");
 922
 923         return 0;
 924 }
 925
 926 enum {
 927         Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
 928         Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
 929         Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
 930         Opt_immutable, Opt_dots, Opt_nodots,
 931         Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
 932         Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
 933         Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
 934         Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
 935         Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
 936         Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
 937 };
 938
 939 static const match_table_t fat_tokens = {
 940         {Opt_check_r, "check=relaxed"},
 941         {Opt_check_s, "check=strict"},
 942         {Opt_check_n, "check=normal"},
 943         {Opt_check_r, "check=r"},
 944         {Opt_check_s, "check=s"},
 945         {Opt_check_n, "check=n"},
 946         {Opt_uid, "uid=%u"},
 947         {Opt_gid, "gid=%u"},
 948         {Opt_umask, "umask=%o"},
 949         {Opt_dmask, "dmask=%o"},
 950         {Opt_fmask, "fmask=%o"},
 951         {Opt_allow_utime, "allow_utime=%o"},
 952         {Opt_codepage, "codepage=%u"},
 953         {Opt_usefree, "usefree"},
 954         {Opt_nocase, "nocase"},
 955         {Opt_quiet, "quiet"},
 956         {Opt_showexec, "showexec"},
 957         {Opt_debug, "debug"},
 958         {Opt_immutable, "sys_immutable"},
 959         {Opt_flush, "flush"},
 960         {Opt_tz_utc, "tz=UTC"},
 961         {Opt_time_offset, "time_offset=%d"},
 962         {Opt_err_cont, "errors=continue"},
 963         {Opt_err_panic, "errors=panic"},
 964         {Opt_err_ro, "errors=remount-ro"},
 965         {Opt_discard, "discard"},
 966         {Opt_nfs_stale_rw, "nfs"},
 967         {Opt_nfs_stale_rw, "nfs=stale_rw"},
 968         {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
 969         {Opt_dos1xfloppy, "dos1xfloppy"},
 970         {Opt_obsolete, "conv=binary"},
 971         {Opt_obsolete, "conv=text"},
 972         {Opt_obsolete, "conv=auto"},
 973         {Opt_obsolete, "conv=b"},
 974         {Opt_obsolete, "conv=t"},
 975         {Opt_obsolete, "conv=a"},
 976         {Opt_obsolete, "fat=%u"},
 977         {Opt_obsolete, "blocksize=%u"},
 978         {Opt_obsolete, "cvf_format=%20s"},
 979         {Opt_obsolete, "cvf_options=%100s"},
 980         {Opt_obsolete, "posix"},
 981         {Opt_err, NULL},
 982 };
 983 static const match_table_t msdos_tokens = {
 984         {Opt_nodots, "nodots"},
 985         {Opt_nodots, "dotsOK=no"},
 986         {Opt_dots, "dots"},
 987         {Opt_dots, "dotsOK=yes"},
 988         {Opt_err, NULL}
 989 };
 990 static const match_table_t vfat_tokens = {
 991         {Opt_charset, "iocharset=%s"},
 992         {Opt_shortname_lower, "shortname=lower"},
 993         {Opt_shortname_win95, "shortname=win95"},
 994         {Opt_shortname_winnt, "shortname=winnt"},
 995         {Opt_shortname_mixed, "shortname=mixed"},
 996         {Opt_utf8_no, "utf8=0"},                /* 0 or no or false */
 997         {Opt_utf8_no, "utf8=no"},
 998         {Opt_utf8_no, "utf8=false"},
 999         {Opt_utf8_yes, "utf8=1"},               /* empty or 1 or yes or true */
1000         {Opt_utf8_yes, "utf8=yes"},
1001         {Opt_utf8_yes, "utf8=true"},
1002         {Opt_utf8_yes, "utf8"},
1003         {Opt_uni_xl_no, "uni_xlate=0"},         /* 0 or no or false */
1004         {Opt_uni_xl_no, "uni_xlate=no"},
1005         {Opt_uni_xl_no, "uni_xlate=false"},
1006         {Opt_uni_xl_yes, "uni_xlate=1"},        /* empty or 1 or yes or true */
1007         {Opt_uni_xl_yes, "uni_xlate=yes"},
1008         {Opt_uni_xl_yes, "uni_xlate=true"},
1009         {Opt_uni_xl_yes, "uni_xlate"},
1010         {Opt_nonumtail_no, "nonumtail=0"},      /* 0 or no or false */
1011         {Opt_nonumtail_no, "nonumtail=no"},
1012         {Opt_nonumtail_no, "nonumtail=false"},
1013         {Opt_nonumtail_yes, "nonumtail=1"},     /* empty or 1 or yes or true */
1014         {Opt_nonumtail_yes, "nonumtail=yes"},
1015         {Opt_nonumtail_yes, "nonumtail=true"},
1016         {Opt_nonumtail_yes, "nonumtail"},
1017         {Opt_rodir, "rodir"},
1018         {Opt_err, NULL}
1019 };
1020
1021 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1022                          int silent, int *debug, struct fat_mount_options *opts)
1023 {
1024         char *p;
1025         substring_t args[MAX_OPT_ARGS];
1026         int option;
1027         char *iocharset;
1028
1029         opts->isvfat = is_vfat;
1030
1031         opts->fs_uid = current_uid();
1032         opts->fs_gid = current_gid();
1033         opts->fs_fmask = opts->fs_dmask = current_umask();
1034         opts->allow_utime = -1;
1035         opts->codepage = fat_default_codepage;
1036         opts->iocharset = fat_default_iocharset;
1037         if (is_vfat) {
1038                 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1039                 opts->rodir = 0;
1040         } else {
1041                 opts->shortname = 0;
1042                 opts->rodir = 1;
1043         }
1044         opts->name_check = 'n';
1045         opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
1046         opts->utf8 = opts->unicode_xlate = 0;
1047         opts->numtail = 1;
1048         opts->usefree = opts->nocase = 0;
1049         opts->tz_set = 0;
1050         opts->nfs = 0;
1051         opts->errors = FAT_ERRORS_RO;
1052         *debug = 0;
1053
1054         if (!options)
1055                 goto out;
1056
1057         while ((p = strsep(&options, ",")) != NULL) {
1058                 int token;
1059                 if (!*p)
1060                         continue;
1061
1062                 token = match_token(p, fat_tokens, args);
1063                 if (token == Opt_err) {
1064                         if (is_vfat)
1065                                 token = match_token(p, vfat_tokens, args);
1066                         else
1067                                 token = match_token(p, msdos_tokens, args);
1068                 }
1069                 switch (token) {
1070                 case Opt_check_s:
1071                         opts->name_check = 's';
1072                         break;
1073                 case Opt_check_r:
1074                         opts->name_check = 'r';
1075                         break;
1076                 case Opt_check_n:
1077                         opts->name_check = 'n';
1078                         break;
1079                 case Opt_usefree:
1080                         opts->usefree = 1;
1081                         break;
1082                 case Opt_nocase:
1083                         if (!is_vfat)
1084                                 opts->nocase = 1;
1085                         else {
1086                                 /* for backward compatibility */
1087                                 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1088                                         | VFAT_SFN_CREATE_WIN95;
1089                         }
1090                         break;
1091                 case Opt_quiet:
1092                         opts->quiet = 1;
1093                         break;
1094                 case Opt_showexec:
1095                         opts->showexec = 1;
1096                         break;
1097                 case Opt_debug:
1098                         *debug = 1;
1099                         break;
1100                 case Opt_immutable:
1101                         opts->sys_immutable = 1;
1102                         break;
1103                 case Opt_uid:
1104                         if (match_int(&args[0], &option))
1105                                 return -EINVAL;
1106                         opts->fs_uid = make_kuid(current_user_ns(), option);
1107                         if (!uid_valid(opts->fs_uid))
1108                                 return -EINVAL;
1109                         break;
1110                 case Opt_gid:
1111                         if (match_int(&args[0], &option))
1112                                 return -EINVAL;
1113                         opts->fs_gid = make_kgid(current_user_ns(), option);
1114                         if (!gid_valid(opts->fs_gid))
1115                                 return -EINVAL;
1116                         break;
1117                 case Opt_umask:
1118                         if (match_octal(&args[0], &option))
1119                                 return -EINVAL;
1120                         opts->fs_fmask = opts->fs_dmask = option;
1121                         break;
1122                 case Opt_dmask:
1123                         if (match_octal(&args[0], &option))
1124                                 return -EINVAL;
1125                         opts->fs_dmask = option;
1126                         break;
1127                 case Opt_fmask:
1128                         if (match_octal(&args[0], &option))
1129                                 return -EINVAL;
1130                         opts->fs_fmask = option;
1131                         break;
1132                 case Opt_allow_utime:
1133                         if (match_octal(&args[0], &option))
1134                                 return -EINVAL;
1135                         opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1136                         break;
1137                 case Opt_codepage:
1138                         if (match_int(&args[0], &option))
1139                                 return -EINVAL;
1140                         opts->codepage = option;
1141                         break;
1142                 case Opt_flush:
1143                         opts->flush = 1;
1144                         break;
1145                 case Opt_time_offset:
1146                         if (match_int(&args[0], &option))
1147                                 return -EINVAL;
1148                         if (option < -12 * 60 || option > 12 * 60)
1149                                 return -EINVAL;
1150                         opts->tz_set = 1;
1151                         opts->time_offset = option;
1152                         break;
1153                 case Opt_tz_utc:
1154                         opts->tz_set = 1;
1155                         opts->time_offset = 0;
1156                         break;
1157                 case Opt_err_cont:
1158                         opts->errors = FAT_ERRORS_CONT;
1159                         break;
1160                 case Opt_err_panic:
1161                         opts->errors = FAT_ERRORS_PANIC;
1162                         break;
1163                 case Opt_err_ro:
1164                         opts->errors = FAT_ERRORS_RO;
1165                         break;
1166                 case Opt_nfs_stale_rw:
1167                         opts->nfs = FAT_NFS_STALE_RW;
1168                         break;
1169                 case Opt_nfs_nostale_ro:
1170                         opts->nfs = FAT_NFS_NOSTALE_RO;
1171                         break;
1172                 case Opt_dos1xfloppy:
1173                         opts->dos1xfloppy = 1;
1174                         break;
1175
1176                 /* msdos specific */
1177                 case Opt_dots:
1178                         opts->dotsOK = 1;
1179                         break;
1180                 case Opt_nodots:
1181                         opts->dotsOK = 0;
1182                         break;
1183
1184                 /* vfat specific */
1185                 case Opt_charset:
1186                         if (opts->iocharset != fat_default_iocharset)
1187                                 kfree(opts->iocharset);
1188                         iocharset = match_strdup(&args[0]);
1189                         if (!iocharset)
1190                                 return -ENOMEM;
1191                         opts->iocharset = iocharset;
1192                         break;
1193                 case Opt_shortname_lower:
1194                         opts->shortname = VFAT_SFN_DISPLAY_LOWER
1195                                         | VFAT_SFN_CREATE_WIN95;
1196                         break;
1197                 case Opt_shortname_win95:
1198                         opts->shortname = VFAT_SFN_DISPLAY_WIN95
1199                                         | VFAT_SFN_CREATE_WIN95;
1200                         break;
1201                 case Opt_shortname_winnt:
1202                         opts->shortname = VFAT_SFN_DISPLAY_WINNT
1203                                         | VFAT_SFN_CREATE_WINNT;
1204                         break;
1205                 case Opt_shortname_mixed:
1206                         opts->shortname = VFAT_SFN_DISPLAY_WINNT
1207                                         | VFAT_SFN_CREATE_WIN95;
1208                         break;
1209                 case Opt_utf8_no:               /* 0 or no or false */
1210                         opts->utf8 = 0;
1211                         break;
1212                 case Opt_utf8_yes:              /* empty or 1 or yes or true */
1213                         opts->utf8 = 1;
1214                         break;
1215                 case Opt_uni_xl_no:             /* 0 or no or false */
1216                         opts->unicode_xlate = 0;
1217                         break;
1218                 case Opt_uni_xl_yes:            /* empty or 1 or yes or true */
1219                         opts->unicode_xlate = 1;
1220                         break;
1221                 case Opt_nonumtail_no:          /* 0 or no or false */
1222                         opts->numtail = 1;      /* negated option */
1223                         break;
1224                 case Opt_nonumtail_yes:         /* empty or 1 or yes or true */
1225                         opts->numtail = 0;      /* negated option */
1226                         break;
1227                 case Opt_rodir:
1228                         opts->rodir = 1;
1229                         break;
1230                 case Opt_discard:
1231                         opts->discard = 1;
1232                         break;
1233
1234                 /* obsolete mount options */
1235                 case Opt_obsolete:
1236                         fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1237                                "not supported now", p);
1238                         break;
1239                 /* unknown option */
1240                 default:
1241                         if (!silent) {
1242                                 fat_msg(sb, KERN_ERR,
1243                                        "Unrecognized mount option \"%s\" "
1244                                        "or missing value", p);
1245                         }
1246                         return -EINVAL;
1247                 }
1248         }
1249
1250 out:
1251         /* UTF-8 doesn't provide FAT semantics */
1252         if (!strcmp(opts->iocharset, "utf8")) {
1253                 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1254                        " for FAT filesystems, filesystem will be "
1255                        "case sensitive!");
1256         }
1257
1258         /* If user doesn't specify allow_utime, it's initialized from dmask. */
1259         if (opts->allow_utime == (unsigned short)-1)
1260                 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1261         if (opts->unicode_xlate)
1262                 opts->utf8 = 0;
1263         if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1264                 sb->s_flags |= MS_RDONLY;
1265                 sb->s_export_op = &fat_export_ops_nostale;
1266         }
1267
1268         return 0;
1269 }
1270
1271 static int fat_read_root(struct inode *inode)
1272 {
1273         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1274         int error;
1275
1276         MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1277         inode->i_uid = sbi->options.fs_uid;
1278         inode->i_gid = sbi->options.fs_gid;
1279         inode->i_version++;
1280         inode->i_generation = 0;
1281         inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1282         inode->i_op = sbi->dir_ops;
1283         inode->i_fop = &fat_dir_operations;
1284         if (sbi->fat_bits == 32) {
1285                 MSDOS_I(inode)->i_start = sbi->root_cluster;
1286                 error = fat_calc_dir_size(inode);
1287                 if (error < 0)
1288                         return error;
1289         } else {
1290                 MSDOS_I(inode)->i_start = 0;
1291                 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1292         }
1293         inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1294                            & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1295         MSDOS_I(inode)->i_logstart = 0;
1296         MSDOS_I(inode)->mmu_private = inode->i_size;
1297
1298         fat_save_attrs(inode, ATTR_DIR);
1299         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1300         inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1301         set_nlink(inode, fat_subdirs(inode)+2);
1302
1303         return 0;
1304 }
1305
1306 static unsigned long calc_fat_clusters(struct super_block *sb)
1307 {
1308         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1309
1310         /* Divide first to avoid overflow */
1311         if (sbi->fat_bits != 12) {
1312                 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1313                 return ent_per_sec * sbi->fat_length;
1314         }
1315
1316         return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1317 }
1318
1319 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1320 {
1321         if (get_unaligned_le16(&b->sector_size))
1322                 return false;
1323         if (b->sec_per_clus)
1324                 return false;
1325         if (b->reserved)
1326                 return false;
1327         if (b->fats)
1328                 return false;
1329         if (get_unaligned_le16(&b->dir_entries))
1330                 return false;
1331         if (get_unaligned_le16(&b->sectors))
1332                 return false;
1333         if (b->media)
1334                 return false;
1335         if (b->fat_length)
1336                 return false;
1337         if (b->secs_track)
1338                 return false;
1339         if (b->heads)
1340                 return false;
1341         return true;
1342 }
1343
1344 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1345         int silent, struct fat_bios_param_block *bpb)
1346 {
1347         int error = -EINVAL;
1348
1349         /* Read in BPB ... */
1350         memset(bpb, 0, sizeof(*bpb));
1351         bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1352         bpb->fat_sec_per_clus = b->sec_per_clus;
1353         bpb->fat_reserved = le16_to_cpu(b->reserved);
1354         bpb->fat_fats = b->fats;
1355         bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1356         bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1357         bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1358         bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1359
1360         bpb->fat16_state = b->fat16.state;
1361         bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1362
1363         bpb->fat32_length = le32_to_cpu(b->fat32.length);
1364         bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1365         bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1366         bpb->fat32_state = b->fat32.state;
1367         bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1368
1369         /* Validate this looks like a FAT filesystem BPB */
1370         if (!bpb->fat_reserved) {
1371                 if (!silent)
1372                         fat_msg(sb, KERN_ERR,
1373                                 "bogus number of reserved sectors");
1374                 goto out;
1375         }
1376         if (!bpb->fat_fats) {
1377                 if (!silent)
1378                         fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1379                 goto out;
1380         }
1381
1382         /*
1383          * Earlier we checked here that b->secs_track and b->head are nonzero,
1384          * but it turns out valid FAT filesystems can have zero there.
1385          */
1386
1387         if (!fat_valid_media(b->media)) {
1388                 if (!silent)
1389                         fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1390                                 (unsigned)b->media);
1391                 goto out;
1392         }
1393
1394         if (!is_power_of_2(bpb->fat_sector_size)
1395             || (bpb->fat_sector_size < 512)
1396             || (bpb->fat_sector_size > 4096)) {
1397                 if (!silent)
1398                         fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1399                                (unsigned)bpb->fat_sector_size);
1400                 goto out;
1401         }
1402
1403         if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1404                 if (!silent)
1405                         fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1406                                 (unsigned)bpb->fat_sec_per_clus);
1407                 goto out;
1408         }
1409
1410         error = 0;
1411
1412 out:
1413         return error;
1414 }
1415
1416 static int fat_read_static_bpb(struct super_block *sb,
1417         struct fat_boot_sector *b, int silent,
1418         struct fat_bios_param_block *bpb)
1419 {
1420         static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1421
1422         struct fat_floppy_defaults *fdefaults = NULL;
1423         int error = -EINVAL;
1424         sector_t bd_sects;
1425         unsigned i;
1426
1427         bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1428
1429         /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1430         if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1431                 if (!silent)
1432                         fat_msg(sb, KERN_ERR,
1433                                 "%s; no bootstrapping code", notdos1x);
1434                 goto out;
1435         }
1436
1437         /*
1438          * If any value in this region is non-zero, it isn't archaic
1439          * DOS.
1440          */
1441         if (!fat_bpb_is_zero(b)) {
1442                 if (!silent)
1443                         fat_msg(sb, KERN_ERR,
1444                                 "%s; DOS 2.x BPB is non-zero", notdos1x);
1445                 goto out;
1446         }
1447
1448         for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1449                 if (floppy_defaults[i].nr_sectors == bd_sects) {
1450                         fdefaults = &floppy_defaults[i];
1451                         break;
1452                 }
1453         }
1454
1455         if (fdefaults == NULL) {
1456                 if (!silent)
1457                         fat_msg(sb, KERN_WARNING,
1458                                 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1459                                 (u64)bd_sects);
1460                 goto out;
1461         }
1462
1463         if (!silent)
1464                 fat_msg(sb, KERN_INFO,
1465                         "This looks like a DOS 1.x volume; assuming default BPB values");
1466
1467         memset(bpb, 0, sizeof(*bpb));
1468         bpb->fat_sector_size = SECTOR_SIZE;
1469         bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1470         bpb->fat_reserved = 1;
1471         bpb->fat_fats = 2;
1472         bpb->fat_dir_entries = fdefaults->dir_entries;
1473         bpb->fat_sectors = fdefaults->nr_sectors;
1474         bpb->fat_fat_length = fdefaults->fat_length;
1475
1476         error = 0;
1477
1478 out:
1479         return error;
1480 }
1481
1482 /*
1483  * Read the super block of an MS-DOS FS.
1484  */
1485 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1486                    void (*setup)(struct super_block *))
1487 {
1488         struct inode *root_inode = NULL, *fat_inode = NULL;
1489         struct inode *fsinfo_inode = NULL;
1490         struct buffer_head *bh;
1491         struct fat_bios_param_block bpb;
1492         struct msdos_sb_info *sbi;
1493         u16 logical_sector_size;
1494         u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1495         int debug;
1496         long error;
1497         char buf[50];
1498
1499         /*
1500          * GFP_KERNEL is ok here, because while we do hold the
1501          * supeblock lock, memory pressure can't call back into
1502          * the filesystem, since we're only just about to mount
1503          * it and have no inodes etc active!
1504          */
1505         sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1506         if (!sbi)
1507                 return -ENOMEM;
1508         sb->s_fs_info = sbi;
1509
1510         sb->s_flags |= MS_NODIRATIME;
1511         sb->s_magic = MSDOS_SUPER_MAGIC;
1512         sb->s_op = &fat_sops;
1513         sb->s_export_op = &fat_export_ops;
1514         mutex_init(&sbi->nfs_build_inode_lock);
1515         ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1516                              DEFAULT_RATELIMIT_BURST);
1517
1518         error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1519         if (error)
1520                 goto out_fail;
1521
1522         setup(sb); /* flavour-specific stuff that needs options */
1523
1524         error = -EIO;
1525         sb_min_blocksize(sb, 512);
1526         bh = sb_bread(sb, 0);
1527         if (bh == NULL) {
1528                 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1529                 goto out_fail;
1530         }
1531
1532         error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1533                 &bpb);
1534         if (error == -EINVAL && sbi->options.dos1xfloppy)
1535                 error = fat_read_static_bpb(sb,
1536                         (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1537         brelse(bh);
1538
1539         if (error == -EINVAL)
1540                 goto out_invalid;
1541         else if (error)
1542                 goto out_fail;
1543
1544         logical_sector_size = bpb.fat_sector_size;
1545         sbi->sec_per_clus = bpb.fat_sec_per_clus;
1546
1547         error = -EIO;
1548         if (logical_sector_size < sb->s_blocksize) {
1549                 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1550                        " (logical sector size = %u)", logical_sector_size);
1551                 goto out_fail;
1552         }
1553
1554         if (logical_sector_size > sb->s_blocksize) {
1555                 struct buffer_head *bh_resize;
1556
1557                 if (!sb_set_blocksize(sb, logical_sector_size)) {
1558                         fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1559                                logical_sector_size);
1560                         goto out_fail;
1561                 }
1562
1563                 /* Verify that the larger boot sector is fully readable */
1564                 bh_resize = sb_bread(sb, 0);
1565                 if (bh_resize == NULL) {
1566                         fat_msg(sb, KERN_ERR, "unable to read boot sector"
1567                                " (logical sector size = %lu)",
1568                                sb->s_blocksize);
1569                         goto out_fail;
1570                 }
1571                 brelse(bh_resize);
1572         }
1573
1574         mutex_init(&sbi->s_lock);
1575         sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1576         sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1577         sbi->fats = bpb.fat_fats;
1578         sbi->fat_bits = 0;              /* Don't know yet */
1579         sbi->fat_start = bpb.fat_reserved;
1580         sbi->fat_length = bpb.fat_fat_length;
1581         sbi->root_cluster = 0;
1582         sbi->free_clusters = -1;        /* Don't know yet */
1583         sbi->free_clus_valid = 0;
1584         sbi->prev_free = FAT_START_ENT;
1585         sb->s_maxbytes = 0xffffffff;
1586
1587         if (!sbi->fat_length && bpb.fat32_length) {
1588                 struct fat_boot_fsinfo *fsinfo;
1589                 struct buffer_head *fsinfo_bh;
1590
1591                 /* Must be FAT32 */
1592                 sbi->fat_bits = 32;
1593                 sbi->fat_length = bpb.fat32_length;
1594                 sbi->root_cluster = bpb.fat32_root_cluster;
1595
1596                 /* MC - if info_sector is 0, don't multiply by 0 */
1597                 sbi->fsinfo_sector = bpb.fat32_info_sector;
1598                 if (sbi->fsinfo_sector == 0)
1599                         sbi->fsinfo_sector = 1;
1600
1601                 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1602                 if (fsinfo_bh == NULL) {
1603                         fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1604                                " (sector = %lu)", sbi->fsinfo_sector);
1605                         goto out_fail;
1606                 }
1607
1608                 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1609                 if (!IS_FSINFO(fsinfo)) {
1610                         fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1611                                "0x%08x, 0x%08x (sector = %lu)",
1612                                le32_to_cpu(fsinfo->signature1),
1613                                le32_to_cpu(fsinfo->signature2),
1614                                sbi->fsinfo_sector);
1615                 } else {
1616                         if (sbi->options.usefree)
1617                                 sbi->free_clus_valid = 1;
1618                         sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1619                         sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1620                 }
1621
1622                 brelse(fsinfo_bh);
1623         }
1624
1625         /* interpret volume ID as a little endian 32 bit integer */
1626         if (sbi->fat_bits == 32)
1627                 sbi->vol_id = bpb.fat32_vol_id;
1628         else /* fat 16 or 12 */
1629                 sbi->vol_id = bpb.fat16_vol_id;
1630
1631         sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1632         sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1633
1634         sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1635         sbi->dir_entries = bpb.fat_dir_entries;
1636         if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1637                 if (!silent)
1638                         fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
1639                                " (%u)", sbi->dir_entries);
1640                 goto out_invalid;
1641         }
1642
1643         rootdir_sectors = sbi->dir_entries
1644                 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1645         sbi->data_start = sbi->dir_start + rootdir_sectors;
1646         total_sectors = bpb.fat_sectors;
1647         if (total_sectors == 0)
1648                 total_sectors = bpb.fat_total_sect;
1649
1650         total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1651
1652         if (sbi->fat_bits != 32)
1653                 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1654
1655         /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1656         if (sbi->fat_bits == 32)
1657                 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1658         else /* fat 16 or 12 */
1659                 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1660
1661         /* check that FAT table does not overflow */
1662         fat_clusters = calc_fat_clusters(sb);
1663         total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1664         if (total_clusters > MAX_FAT(sb)) {
1665                 if (!silent)
1666                         fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1667                                total_clusters);
1668                 goto out_invalid;
1669         }
1670
1671         sbi->max_cluster = total_clusters + FAT_START_ENT;
1672         /* check the free_clusters, it's not necessarily correct */
1673         if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1674                 sbi->free_clusters = -1;
1675         /* check the prev_free, it's not necessarily correct */
1676         sbi->prev_free %= sbi->max_cluster;
1677         if (sbi->prev_free < FAT_START_ENT)
1678                 sbi->prev_free = FAT_START_ENT;
1679
1680         /* set up enough so that it can read an inode */
1681         fat_hash_init(sb);
1682         dir_hash_init(sb);
1683         fat_ent_access_init(sb);
1684
1685         /*
1686          * The low byte of FAT's first entry must have same value with
1687          * media-field.  But in real world, too many devices is
1688          * writing wrong value.  So, removed that validity check.
1689          *
1690          * if (FAT_FIRST_ENT(sb, media) != first)
1691          */
1692
1693         error = -EINVAL;
1694         sprintf(buf, "cp%d", sbi->options.codepage);
1695         sbi->nls_disk = load_nls(buf);
1696         if (!sbi->nls_disk) {
1697                 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1698                 goto out_fail;
1699         }
1700
1701         /* FIXME: utf8 is using iocharset for upper/lower conversion */
1702         if (sbi->options.isvfat) {
1703                 sbi->nls_io = load_nls(sbi->options.iocharset);
1704                 if (!sbi->nls_io) {
1705                         fat_msg(sb, KERN_ERR, "IO charset %s not found",
1706                                sbi->options.iocharset);
1707                         goto out_fail;
1708                 }
1709         }
1710
1711         error = -ENOMEM;
1712         fat_inode = new_inode(sb);
1713         if (!fat_inode)
1714                 goto out_fail;
1715         MSDOS_I(fat_inode)->i_pos = 0;
1716         sbi->fat_inode = fat_inode;
1717
1718         fsinfo_inode = new_inode(sb);
1719         if (!fsinfo_inode)
1720                 goto out_fail;
1721         fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1722         sbi->fsinfo_inode = fsinfo_inode;
1723         insert_inode_hash(fsinfo_inode);
1724
1725         root_inode = new_inode(sb);
1726         if (!root_inode)
1727                 goto out_fail;
1728         root_inode->i_ino = MSDOS_ROOT_INO;
1729         root_inode->i_version = 1;
1730         error = fat_read_root(root_inode);
1731         if (error < 0) {
1732                 iput(root_inode);
1733                 goto out_fail;
1734         }
1735         error = -ENOMEM;
1736         insert_inode_hash(root_inode);
1737         fat_attach(root_inode, 0);
1738         sb->s_root = d_make_root(root_inode);
1739         if (!sb->s_root) {
1740                 fat_msg(sb, KERN_ERR, "get root inode failed");
1741                 goto out_fail;
1742         }
1743
1744         if (sbi->options.discard) {
1745                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1746                 if (!blk_queue_discard(q))
1747                         fat_msg(sb, KERN_WARNING,
1748                                         "mounting with \"discard\" option, but "
1749                                         "the device does not support discard");
1750         }
1751
1752         fat_set_state(sb, 1, 0);
1753         return 0;
1754
1755 out_invalid:
1756         error = -EINVAL;
1757         if (!silent)
1758                 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1759
1760 out_fail:
1761         if (fsinfo_inode)
1762                 iput(fsinfo_inode);
1763         if (fat_inode)
1764                 iput(fat_inode);
1765         unload_nls(sbi->nls_io);
1766         unload_nls(sbi->nls_disk);
1767         if (sbi->options.iocharset != fat_default_iocharset)
1768                 kfree(sbi->options.iocharset);
1769         sb->s_fs_info = NULL;
1770         kfree(sbi);
1771         return error;
1772 }
1773
1774 EXPORT_SYMBOL_GPL(fat_fill_super);
1775
1776 /*
1777  * helper function for fat_flush_inodes.  This writes both the inode
1778  * and the file data blocks, waiting for in flight data blocks before
1779  * the start of the call.  It does not wait for any io started
1780  * during the call
1781  */
1782 static int writeback_inode(struct inode *inode)
1783 {
1784
1785         int ret;
1786
1787         /* if we used wait=1, sync_inode_metadata waits for the io for the
1788         * inode to finish.  So wait=0 is sent down to sync_inode_metadata
1789         * and filemap_fdatawrite is used for the data blocks
1790         */
1791         ret = sync_inode_metadata(inode, 0);
1792         if (!ret)
1793                 ret = filemap_fdatawrite(inode->i_mapping);
1794         return ret;
1795 }
1796
1797 /*
1798  * write data and metadata corresponding to i1 and i2.  The io is
1799  * started but we do not wait for any of it to finish.
1800  *
1801  * filemap_flush is used for the block device, so if there is a dirty
1802  * page for a block already in flight, we will not wait and start the
1803  * io over again
1804  */
1805 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1806 {
1807         int ret = 0;
1808         if (!MSDOS_SB(sb)->options.flush)
1809                 return 0;
1810         if (i1)
1811                 ret = writeback_inode(i1);
1812         if (!ret && i2)
1813                 ret = writeback_inode(i2);
1814         if (!ret) {
1815                 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1816                 ret = filemap_flush(mapping);
1817         }
1818         return ret;
1819 }
1820 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1821
1822 static int __init init_fat_fs(void)
1823 {
1824         int err;
1825
1826         err = fat_cache_init();
1827         if (err)
1828                 return err;
1829
1830         err = fat_init_inodecache();
1831         if (err)
1832                 goto failed;
1833
1834         return 0;
1835
1836 failed:
1837         fat_cache_destroy();
1838         return err;
1839 }
1840
1841 static void __exit exit_fat_fs(void)
1842 {
1843         fat_cache_destroy();
1844         fat_destroy_inodecache();
1845 }
1846
1847 module_init(init_fat_fs)
1848 module_exit(exit_fat_fs)
1849
1850 MODULE_LICENSE("GPL");