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/init.h>
  15 #include <linux/time.h>
  16 #include <linux/slab.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/mpage.h>
  20 #include <linux/buffer_head.h>
  21 #include <linux/mount.h>
  22 #include <linux/aio.h>
  23 #include <linux/vfs.h>
  24 #include <linux/parser.h>
  25 #include <linux/uio.h>
  26 #include <linux/writeback.h>
  27 #include <linux/log2.h>
  28 #include <linux/hash.h>
  29 #include <linux/blkdev.h>
  30 #include <asm/unaligned.h>
  31 #include "fat.h"
  32
  33 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
  34 /* if user don't select VFAT, this is undefined. */
  35 #define CONFIG_FAT_DEFAULT_IOCHARSET    ""
  36 #endif
  37
  38 #define KB_IN_SECTORS 2
  39
  40 /*
  41  * A deserialized copy of the on-disk structure laid out in struct
  42  * fat_boot_sector.
  43  */
  44 struct fat_bios_param_block {
  45         u16     fat_sector_size;
  46         u8      fat_sec_per_clus;
  47         u16     fat_reserved;
  48         u8      fat_fats;
  49         u16     fat_dir_entries;
  50         u16     fat_sectors;
  51         u16     fat_fat_length;
  52         u32     fat_total_sect;
  53
  54         u8      fat16_state;
  55         u32     fat16_vol_id;
  56
  57         u32     fat32_length;
  58         u32     fat32_root_cluster;
  59         u16     fat32_info_sector;
  60         u8      fat32_state;
  61         u32     fat32_vol_id;
  62 };
  63
  64 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
  65 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
  66
  67 static struct fat_floppy_defaults {
  68         unsigned nr_sectors;
  69         unsigned sec_per_clus;
  70         unsigned dir_entries;
  71         unsigned media;
  72         unsigned fat_length;
  73 } floppy_defaults[] = {
  74 {
  75         .nr_sectors = 160 * KB_IN_SECTORS,
  76         .sec_per_clus = 1,
  77         .dir_entries = 64,
  78         .media = 0xFE,
  79         .fat_length = 1,
  80 },
  81 {
  82         .nr_sectors = 180 * KB_IN_SECTORS,
  83         .sec_per_clus = 1,
  84         .dir_entries = 64,
  85         .media = 0xFC,
  86         .fat_length = 2,
  87 },
  88 {
  89         .nr_sectors = 320 * KB_IN_SECTORS,
  90         .sec_per_clus = 2,
  91         .dir_entries = 112,
  92         .media = 0xFF,
  93         .fat_length = 1,
  94 },
  95 {
  96         .nr_sectors = 360 * KB_IN_SECTORS,
  97         .sec_per_clus = 2,
  98         .dir_entries = 112,
  99         .media = 0xFD,
 100         .fat_length = 2,
 101 },
 102 };
 103
 104 static int fat_add_cluster(struct inode *inode)
 105 {
 106         int err, cluster;
 107
 108         err = fat_alloc_clusters(inode, &cluster, 1);
 109         if (err)
 110                 return err;
 111         /* FIXME: this cluster should be added after data of this
 112          * cluster is writed */
 113         err = fat_chain_add(inode, cluster, 1);
 114         if (err)
 115                 fat_free_clusters(inode, cluster);
 116         return err;
 117 }
 118
 119 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
 120                                   unsigned long *max_blocks,
 121                                   struct buffer_head *bh_result, int create)
 122 {
 123         struct super_block *sb = inode->i_sb;
 124         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 125         unsigned long mapped_blocks;
 126         sector_t phys;
 127         int err, offset;
 128
 129         err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
 130         if (err)
 131                 return err;
 132         if (phys) {
 133                 map_bh(bh_result, sb, phys);
 134                 *max_blocks = min(mapped_blocks, *max_blocks);
 135                 return 0;
 136         }
 137         if (!create)
 138                 return 0;
 139
 140         if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
 141                 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
 142                         MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
 143                 return -EIO;
 144         }
 145
 146         offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
 147         if (!offset) {
 148                 /* TODO: multiple cluster allocation would be desirable. */
 149                 err = fat_add_cluster(inode);
 150                 if (err)
 151                         return err;
 152         }
 153         /* available blocks on this cluster */
 154         mapped_blocks = sbi->sec_per_clus - offset;
 155
 156         *max_blocks = min(mapped_blocks, *max_blocks);
 157         MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
 158         MSDOS_I(inode)->i_disksize = MSDOS_I(inode)->mmu_private;
 159
 160         err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
 161         if (err)
 162                 return err;
 163
 164         BUG_ON(!phys);
 165         BUG_ON(*max_blocks != mapped_blocks);
 166         set_buffer_new(bh_result);
 167         map_bh(bh_result, sb, phys);
 168
 169         return 0;
 170 }
 171
 172 static int fat_get_block(struct inode *inode, sector_t iblock,
 173                          struct buffer_head *bh_result, int create)
 174 {
 175         struct super_block *sb = inode->i_sb;
 176         unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 177         int err;
 178
 179         err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
 180         if (err)
 181                 return err;
 182         bh_result->b_size = max_blocks << sb->s_blocksize_bits;
 183         return 0;
 184 }
 185
 186 static int fat_writepage(struct page *page, struct writeback_control *wbc)
 187 {
 188         return block_write_full_page(page, fat_get_block, wbc);
 189 }
 190
 191 static int fat_writepages(struct address_space *mapping,
 192                           struct writeback_control *wbc)
 193 {
 194         return mpage_writepages(mapping, wbc, fat_get_block);
 195 }
 196
 197 static int fat_readpage(struct file *file, struct page *page)
 198 {
 199         return mpage_readpage(page, fat_get_block);
 200 }
 201
 202 static int fat_readpages(struct file *file, struct address_space *mapping,
 203                          struct list_head *pages, unsigned nr_pages)
 204 {
 205         return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
 206 }
 207
 208 static void fat_write_failed(struct address_space *mapping, loff_t to)
 209 {
 210         struct inode *inode = mapping->host;
 211
 212         if (to > inode->i_size) {
 213                 truncate_pagecache(inode, inode->i_size);
 214                 fat_truncate_blocks(inode, inode->i_size);
 215         }
 216 }
 217
 218 static int fat_write_begin(struct file *file, struct address_space *mapping,
 219                         loff_t pos, unsigned len, unsigned flags,
 220                         struct page **pagep, void **fsdata)
 221 {
 222         int err;
 223
 224         *pagep = NULL;
 225         err = cont_write_begin(file, mapping, pos, len, flags,
 226                                 pagep, fsdata, fat_get_block,
 227                                 &MSDOS_I(mapping->host)->mmu_private);
 228         if (err < 0)
 229                 fat_write_failed(mapping, pos + len);
 230         return err;
 231 }
 232
 233 static int fat_write_end(struct file *file, struct address_space *mapping,
 234                         loff_t pos, unsigned len, unsigned copied,
 235                         struct page *pagep, void *fsdata)
 236 {
 237         struct inode *inode = mapping->host;
 238         int err;
 239         err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
 240         if (err < len)
 241                 fat_write_failed(mapping, pos + len);
 242         if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
 243                 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 244                 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
 245                 mark_inode_dirty(inode);
 246         }
 247         return err;
 248 }
 249
 250 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
 251                              struct iov_iter *iter,
 252                              loff_t offset)
 253 {
 254         struct file *file = iocb->ki_filp;
 255         struct address_space *mapping = file->f_mapping;
 256         struct inode *inode = mapping->host;
 257         size_t count = iov_iter_count(iter);
 258         ssize_t ret;
 259
 260         if (rw == WRITE) {
 261                 /*
 262                  * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
 263                  * so we need to update the ->mmu_private to block boundary.
 264                  *
 265                  * But we must fill the remaining area or hole by nul for
 266                  * updating ->mmu_private.
 267                  *
 268                  * Return 0, and fallback to normal buffered write.
 269                  */
 270                 loff_t size = offset + count;
 271                 if (MSDOS_I(inode)->mmu_private < size)
 272                         return 0;
 273         }
 274
 275         /*
 276          * FAT need to use the DIO_LOCKING for avoiding the race
 277          * condition of fat_get_block() and ->truncate().
 278          */
 279         ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, fat_get_block);
 280         if (ret < 0 && (rw & WRITE))
 281                 fat_write_failed(mapping, offset + count);
 282
 283         return ret;
 284 }
 285
 286 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
 287 {
 288         sector_t blocknr;
 289
 290         /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
 291         down_read(&MSDOS_I(mapping->host)->truncate_lock);
 292         blocknr = generic_block_bmap(mapping, block, fat_get_block);
 293         up_read(&MSDOS_I(mapping->host)->truncate_lock);
 294
 295         return blocknr;
 296 }
 297
 298 static const struct address_space_operations fat_aops = {
 299         .readpage       = fat_readpage,
 300         .readpages      = fat_readpages,
 301         .writepage      = fat_writepage,
 302         .writepages     = fat_writepages,
 303         .write_begin    = fat_write_begin,
 304         .write_end      = fat_write_end,
 305         .direct_IO      = fat_direct_IO,
 306         .bmap           = _fat_bmap
 307 };
 308
 309 /*
 310  * New FAT inode stuff. We do the following:
 311  *      a) i_ino is constant and has nothing with on-disk location.
 312  *      b) FAT manages its own cache of directory entries.
 313  *      c) *This* cache is indexed by on-disk location.
 314  *      d) inode has an associated directory entry, all right, but
 315  *              it may be unhashed.
 316  *      e) currently entries are stored within struct inode. That should
 317  *              change.
 318  *      f) we deal with races in the following way:
 319  *              1. readdir() and lookup() do FAT-dir-cache lookup.
 320  *              2. rename() unhashes the F-d-c entry and rehashes it in
 321  *                      a new place.
 322  *              3. unlink() and rmdir() unhash F-d-c entry.
 323  *              4. fat_write_inode() checks whether the thing is unhashed.
 324  *                      If it is we silently return. If it isn't we do bread(),
 325  *                      check if the location is still valid and retry if it
 326  *                      isn't. Otherwise we do changes.
 327  *              5. Spinlock is used to protect hash/unhash/location check/lookup
 328  *              6. fat_evict_inode() unhashes the F-d-c entry.
 329  *              7. lookup() and readdir() do igrab() if they find a F-d-c entry
 330  *                      and consider negative result as cache miss.
 331  */
 332
 333 static void fat_hash_init(struct super_block *sb)
 334 {
 335         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 336         int i;
 337
 338         spin_lock_init(&sbi->inode_hash_lock);
 339         for (i = 0; i < FAT_HASH_SIZE; i++)
 340                 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
 341 }
 342
 343 static inline unsigned long fat_hash(loff_t i_pos)
 344 {
 345         return hash_32(i_pos, FAT_HASH_BITS);
 346 }
 347
 348 static void dir_hash_init(struct super_block *sb)
 349 {
 350         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 351         int i;
 352
 353         spin_lock_init(&sbi->dir_hash_lock);
 354         for (i = 0; i < FAT_HASH_SIZE; i++)
 355                 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
 356 }
 357
 358 void fat_attach(struct inode *inode, loff_t i_pos)
 359 {
 360         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 361
 362         if (inode->i_ino != MSDOS_ROOT_INO) {
 363                 struct hlist_head *head =   sbi->inode_hashtable
 364                                           + fat_hash(i_pos);
 365
 366                 spin_lock(&sbi->inode_hash_lock);
 367                 MSDOS_I(inode)->i_pos = i_pos;
 368                 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
 369                 spin_unlock(&sbi->inode_hash_lock);
 370         }
 371
 372         /* If NFS support is enabled, cache the mapping of start cluster
 373          * to directory inode. This is used during reconnection of
 374          * dentries to the filesystem root.
 375          */
 376         if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
 377                 struct hlist_head *d_head = sbi->dir_hashtable;
 378                 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
 379
 380                 spin_lock(&sbi->dir_hash_lock);
 381                 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
 382                 spin_unlock(&sbi->dir_hash_lock);
 383         }
 384 }
 385 EXPORT_SYMBOL_GPL(fat_attach);
 386
 387 void fat_detach(struct inode *inode)
 388 {
 389         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 390         spin_lock(&sbi->inode_hash_lock);
 391         MSDOS_I(inode)->i_pos = 0;
 392         hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
 393         spin_unlock(&sbi->inode_hash_lock);
 394
 395         if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
 396                 spin_lock(&sbi->dir_hash_lock);
 397                 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
 398                 spin_unlock(&sbi->dir_hash_lock);
 399         }
 400 }
 401 EXPORT_SYMBOL_GPL(fat_detach);
 402
 403 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
 404 {
 405         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 406         struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
 407         struct msdos_inode_info *i;
 408         struct inode *inode = NULL;
 409
 410         spin_lock(&sbi->inode_hash_lock);
 411         hlist_for_each_entry(i, head, i_fat_hash) {
 412                 BUG_ON(i->vfs_inode.i_sb != sb);
 413                 if (i->i_pos != i_pos)
 414                         continue;
 415                 inode = igrab(&i->vfs_inode);
 416                 if (inode)
 417                         break;
 418         }
 419         spin_unlock(&sbi->inode_hash_lock);
 420         return inode;
 421 }
 422
 423 static int is_exec(unsigned char *extension)
 424 {
 425         unsigned char exe_extensions[] = "EXECOMBAT", *walk;
 426
 427         for (walk = exe_extensions; *walk; walk += 3)
 428                 if (!strncmp(extension, walk, 3))
 429                         return 1;
 430         return 0;
 431 }
 432
 433 static int fat_calc_dir_size(struct inode *inode)
 434 {
 435         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 436         int ret, fclus, dclus;
 437
 438         inode->i_size = 0;
 439         if (MSDOS_I(inode)->i_start == 0)
 440                 return 0;
 441
 442         ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
 443         if (ret < 0)
 444                 return ret;
 445         inode->i_size = (fclus + 1) << sbi->cluster_bits;
 446
 447         return 0;
 448 }
 449
 450 /* doesn't deal with root inode */
 451 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
 452 {
 453         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 454         int error;
 455
 456         MSDOS_I(inode)->i_pos = 0;
 457         inode->i_uid = sbi->options.fs_uid;
 458         inode->i_gid = sbi->options.fs_gid;
 459         inode->i_version++;
 460         inode->i_generation = get_seconds();
 461
 462         if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
 463                 inode->i_generation &= ~1;
 464                 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
 465                 inode->i_op = sbi->dir_ops;
 466                 inode->i_fop = &fat_dir_operations;
 467
 468                 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
 469                 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
 470                 error = fat_calc_dir_size(inode);
 471                 if (error < 0)
 472                         return error;
 473
 474                 set_nlink(inode, fat_subdirs(inode));
 475         } else { /* not a directory */
 476                 inode->i_generation |= 1;
 477                 inode->i_mode = fat_make_mode(sbi, de->attr,
 478                         ((sbi->options.showexec && !is_exec(de->name + 8))
 479                          ? S_IRUGO|S_IWUGO : S_IRWXUGO));
 480                 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
 481
 482                 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
 483                 inode->i_size = le32_to_cpu(de->size);
 484                 inode->i_op = &fat_file_inode_operations;
 485                 inode->i_fop = &fat_file_operations;
 486                 inode->i_mapping->a_ops = &fat_aops;
 487         }
 488
 489         MSDOS_I(inode)->mmu_private = inode->i_size;
 490         MSDOS_I(inode)->i_disksize = round_up(inode->i_size,
 491                 inode->i_sb->s_blocksize);
 492
 493         if (de->attr & ATTR_SYS) {
 494                 if (sbi->options.sys_immutable)
 495                         inode->i_flags |= S_IMMUTABLE;
 496         }
 497         fat_save_attrs(inode, de->attr);
 498
 499         inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
 500                            & ~((loff_t)sbi->cluster_size - 1)) >> 9;
 501
 502         fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
 503         if (sbi->options.isvfat) {
 504                 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
 505                                   de->cdate, de->ctime_cs);
 506                 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
 507         } else
 508                 inode->i_ctime = inode->i_atime = inode->i_mtime;
 509
 510         return 0;
 511 }
 512
 513 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
 514 {
 515         if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
 516                 mutex_lock(&sbi->nfs_build_inode_lock);
 517 }
 518
 519 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
 520 {
 521         if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
 522                 mutex_unlock(&sbi->nfs_build_inode_lock);
 523 }
 524
 525 struct inode *fat_build_inode(struct super_block *sb,
 526                         struct msdos_dir_entry *de, loff_t i_pos)
 527 {
 528         struct inode *inode;
 529         int err;
 530
 531         fat_lock_build_inode(MSDOS_SB(sb));
 532         inode = fat_iget(sb, i_pos);
 533         if (inode)
 534                 goto out;
 535         inode = new_inode(sb);
 536         if (!inode) {
 537                 inode = ERR_PTR(-ENOMEM);
 538                 goto out;
 539         }
 540         inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
 541         inode->i_version = 1;
 542         err = fat_fill_inode(inode, de);
 543         if (err) {
 544                 iput(inode);
 545                 inode = ERR_PTR(err);
 546                 goto out;
 547         }
 548         fat_attach(inode, i_pos);
 549         insert_inode_hash(inode);
 550 out:
 551         fat_unlock_build_inode(MSDOS_SB(sb));
 552         return inode;
 553 }
 554
 555 EXPORT_SYMBOL_GPL(fat_build_inode);
 556
 557 static void fat_evict_inode(struct inode *inode)
 558 {
 559         truncate_inode_pages_final(&inode->i_data);
 560         if (!inode->i_nlink) {
 561                 inode->i_size = 0;
 562                 fat_truncate_blocks(inode, 0);
 563         }
 564         invalidate_inode_buffers(inode);
 565         clear_inode(inode);
 566         fat_cache_inval_inode(inode);
 567         fat_detach(inode);
 568 }
 569
 570 static void fat_set_state(struct super_block *sb,
 571                         unsigned int set, unsigned int force)
 572 {
 573         struct buffer_head *bh;
 574         struct fat_boot_sector *b;
 575         struct msdos_sb_info *sbi = sb->s_fs_info;
 576
 577         /* do not change any thing if mounted read only */
 578         if ((sb->s_flags & MS_RDONLY) && !force)
 579                 return;
 580
 581         /* do not change state if fs was dirty */
 582         if (sbi->dirty) {
 583                 /* warn only on set (mount). */
 584                 if (set)
 585                         fat_msg(sb, KERN_WARNING, "Volume was not properly "
 586                                 "unmounted. Some data may be corrupt. "
 587                                 "Please run fsck.");
 588                 return;
 589         }
 590
 591         bh = sb_bread(sb, 0);
 592         if (bh == NULL) {
 593                 fat_msg(sb, KERN_ERR, "unable to read boot sector "
 594                         "to mark fs as dirty");
 595                 return;
 596         }
 597
 598         b = (struct fat_boot_sector *) bh->b_data;
 599
 600         if (sbi->fat_bits == 32) {
 601                 if (set)
 602                         b->fat32.state |= FAT_STATE_DIRTY;
 603                 else
 604                         b->fat32.state &= ~FAT_STATE_DIRTY;
 605         } else /* fat 16 and 12 */ {
 606                 if (set)
 607                         b->fat16.state |= FAT_STATE_DIRTY;
 608                 else
 609                         b->fat16.state &= ~FAT_STATE_DIRTY;
 610         }
 611
 612         mark_buffer_dirty(bh);
 613         sync_dirty_buffer(bh);
 614         brelse(bh);
 615 }
 616
 617 static void delayed_free(struct rcu_head *p)
 618 {
 619         struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
 620         unload_nls(sbi->nls_disk);
 621         unload_nls(sbi->nls_io);
 622         if (sbi->options.iocharset != fat_default_iocharset)
 623                 kfree(sbi->options.iocharset);
 624         kfree(sbi);
 625 }
 626
 627 static void fat_put_super(struct super_block *sb)
 628 {
 629         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 630
 631         fat_set_state(sb, 0, 0);
 632
 633         iput(sbi->fsinfo_inode);
 634         iput(sbi->fat_inode);
 635
 636         call_rcu(&sbi->rcu, delayed_free);
 637 }
 638
 639 static struct kmem_cache *fat_inode_cachep;
 640
 641 static struct inode *fat_alloc_inode(struct super_block *sb)
 642 {
 643         struct msdos_inode_info *ei;
 644         ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
 645         if (!ei)
 646                 return NULL;
 647
 648         init_rwsem(&ei->truncate_lock);
 649         return &ei->vfs_inode;
 650 }
 651
 652 static void fat_i_callback(struct rcu_head *head)
 653 {
 654         struct inode *inode = container_of(head, struct inode, i_rcu);
 655         kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
 656 }
 657
 658 static void fat_destroy_inode(struct inode *inode)
 659 {
 660         call_rcu(&inode->i_rcu, fat_i_callback);
 661 }
 662
 663 static void init_once(void *foo)
 664 {
 665         struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
 666
 667         spin_lock_init(&ei->cache_lru_lock);
 668         ei->nr_caches = 0;
 669         ei->cache_valid_id = FAT_CACHE_VALID + 1;
 670         INIT_LIST_HEAD(&ei->cache_lru);
 671         INIT_HLIST_NODE(&ei->i_fat_hash);
 672         INIT_HLIST_NODE(&ei->i_dir_hash);
 673         inode_init_once(&ei->vfs_inode);
 674 }
 675
 676 static int __init fat_init_inodecache(void)
 677 {
 678         fat_inode_cachep = kmem_cache_create("fat_inode_cache",
 679                                              sizeof(struct msdos_inode_info),
 680                                              0, (SLAB_RECLAIM_ACCOUNT|
 681                                                 SLAB_MEM_SPREAD),
 682                                              init_once);
 683         if (fat_inode_cachep == NULL)
 684                 return -ENOMEM;
 685         return 0;
 686 }
 687
 688 static void __exit fat_destroy_inodecache(void)
 689 {
 690         /*
 691          * Make sure all delayed rcu free inodes are flushed before we
 692          * destroy cache.
 693          */
 694         rcu_barrier();
 695         kmem_cache_destroy(fat_inode_cachep);
 696 }
 697
 698 static int fat_remount(struct super_block *sb, int *flags, char *data)
 699 {
 700         int new_rdonly;
 701         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 702         *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
 703
 704         sync_filesystem(sb);
 705
 706         /* make sure we update state on remount. */
 707         new_rdonly = *flags & MS_RDONLY;
 708         if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
 709                 if (new_rdonly)
 710                         fat_set_state(sb, 0, 0);
 711                 else
 712                         fat_set_state(sb, 1, 1);
 713         }
 714         return 0;
 715 }
 716
 717 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
 718 {
 719         struct super_block *sb = dentry->d_sb;
 720         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 721         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 722
 723         /* If the count of free cluster is still unknown, counts it here. */
 724         if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
 725                 int err = fat_count_free_clusters(dentry->d_sb);
 726                 if (err)
 727                         return err;
 728         }
 729
 730         buf->f_type = dentry->d_sb->s_magic;
 731         buf->f_bsize = sbi->cluster_size;
 732         buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
 733         buf->f_bfree = sbi->free_clusters;
 734         buf->f_bavail = sbi->free_clusters;
 735         buf->f_fsid.val[0] = (u32)id;
 736         buf->f_fsid.val[1] = (u32)(id >> 32);
 737         buf->f_namelen =
 738                 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
 739
 740         return 0;
 741 }
 742
 743 static int __fat_write_inode(struct inode *inode, int wait)
 744 {
 745         struct super_block *sb = inode->i_sb;
 746         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 747         struct buffer_head *bh;
 748         struct msdos_dir_entry *raw_entry;
 749         loff_t i_pos;
 750         sector_t blocknr;
 751         int err, offset;
 752
 753         if (inode->i_ino == MSDOS_ROOT_INO)
 754                 return 0;
 755
 756 retry:
 757         i_pos = fat_i_pos_read(sbi, inode);
 758         if (!i_pos)
 759                 return 0;
 760
 761         fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
 762         bh = sb_bread(sb, blocknr);
 763         if (!bh) {
 764                 fat_msg(sb, KERN_ERR, "unable to read inode block "
 765                        "for updating (i_pos %lld)", i_pos);
 766                 return -EIO;
 767         }
 768         spin_lock(&sbi->inode_hash_lock);
 769         if (i_pos != MSDOS_I(inode)->i_pos) {
 770                 spin_unlock(&sbi->inode_hash_lock);
 771                 brelse(bh);
 772                 goto retry;
 773         }
 774
 775         raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
 776         if (S_ISDIR(inode->i_mode))
 777                 raw_entry->size = 0;
 778         else
 779                 raw_entry->size = cpu_to_le32(inode->i_size);
 780         raw_entry->attr = fat_make_attrs(inode);
 781         fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
 782         fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
 783                           &raw_entry->date, NULL);
 784         if (sbi->options.isvfat) {
 785                 __le16 atime;
 786                 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
 787                                   &raw_entry->cdate, &raw_entry->ctime_cs);
 788                 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
 789                                   &raw_entry->adate, NULL);
 790         }
 791         spin_unlock(&sbi->inode_hash_lock);
 792         mark_buffer_dirty(bh);
 793         err = 0;
 794         if (wait)
 795                 err = sync_dirty_buffer(bh);
 796         brelse(bh);
 797         return err;
 798 }
 799
 800 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
 801 {
 802         int err;
 803
 804         if (inode->i_ino == MSDOS_FSINFO_INO) {
 805                 struct super_block *sb = inode->i_sb;
 806
 807                 mutex_lock(&MSDOS_SB(sb)->s_lock);
 808                 err = fat_clusters_flush(sb);
 809                 mutex_unlock(&MSDOS_SB(sb)->s_lock);
 810         } else
 811                 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 812
 813         return err;
 814 }
 815
 816 int fat_sync_inode(struct inode *inode)
 817 {
 818         return __fat_write_inode(inode, 1);
 819 }
 820
 821 EXPORT_SYMBOL_GPL(fat_sync_inode);
 822
 823 static int fat_show_options(struct seq_file *m, struct dentry *root);
 824 static const struct super_operations fat_sops = {
 825         .alloc_inode    = fat_alloc_inode,
 826         .destroy_inode  = fat_destroy_inode,
 827         .write_inode    = fat_write_inode,
 828         .evict_inode    = fat_evict_inode,
 829         .put_super      = fat_put_super,
 830         .statfs         = fat_statfs,
 831         .remount_fs     = fat_remount,
 832
 833         .show_options   = fat_show_options,
 834 };
 835
 836 static int fat_show_options(struct seq_file *m, struct dentry *root)
 837 {
 838         struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
 839         struct fat_mount_options *opts = &sbi->options;
 840         int isvfat = opts->isvfat;
 841
 842         if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
 843                 seq_printf(m, ",uid=%u",
 844                                 from_kuid_munged(&init_user_ns, opts->fs_uid));
 845         if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
 846                 seq_printf(m, ",gid=%u",
 847                                 from_kgid_munged(&init_user_ns, opts->fs_gid));
 848         seq_printf(m, ",fmask=%04o", opts->fs_fmask);
 849         seq_printf(m, ",dmask=%04o", opts->fs_dmask);
 850         if (opts->allow_utime)
 851                 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
 852         if (sbi->nls_disk)
 853                 /* strip "cp" prefix from displayed option */
 854                 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
 855         if (isvfat) {
 856                 if (sbi->nls_io)
 857                         seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
 858
 859                 switch (opts->shortname) {
 860                 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
 861                         seq_puts(m, ",shortname=win95");
 862                         break;
 863                 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
 864                         seq_puts(m, ",shortname=winnt");
 865                         break;
 866                 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
 867                         seq_puts(m, ",shortname=mixed");
 868                         break;
 869                 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
 870                         seq_puts(m, ",shortname=lower");
 871                         break;
 872                 default:
 873                         seq_puts(m, ",shortname=unknown");
 874                         break;
 875                 }
 876         }
 877         if (opts->name_check != 'n')
 878                 seq_printf(m, ",check=%c", opts->name_check);
 879         if (opts->usefree)
 880                 seq_puts(m, ",usefree");
 881         if (opts->quiet)
 882                 seq_puts(m, ",quiet");
 883         if (opts->showexec)
 884                 seq_puts(m, ",showexec");
 885         if (opts->sys_immutable)
 886                 seq_puts(m, ",sys_immutable");
 887         if (!isvfat) {
 888                 if (opts->dotsOK)
 889                         seq_puts(m, ",dotsOK=yes");
 890                 if (opts->nocase)
 891                         seq_puts(m, ",nocase");
 892         } else {
 893                 if (opts->utf8)
 894                         seq_puts(m, ",utf8");
 895                 if (opts->unicode_xlate)
 896                         seq_puts(m, ",uni_xlate");
 897                 if (!opts->numtail)
 898                         seq_puts(m, ",nonumtail");
 899                 if (opts->rodir)
 900                         seq_puts(m, ",rodir");
 901         }
 902         if (opts->flush)
 903                 seq_puts(m, ",flush");
 904         if (opts->tz_set) {
 905                 if (opts->time_offset)
 906                         seq_printf(m, ",time_offset=%d", opts->time_offset);
 907                 else
 908                         seq_puts(m, ",tz=UTC");
 909         }
 910         if (opts->errors == FAT_ERRORS_CONT)
 911                 seq_puts(m, ",errors=continue");
 912         else if (opts->errors == FAT_ERRORS_PANIC)
 913                 seq_puts(m, ",errors=panic");
 914         else
 915                 seq_puts(m, ",errors=remount-ro");
 916         if (opts->nfs == FAT_NFS_NOSTALE_RO)
 917                 seq_puts(m, ",nfs=nostale_ro");
 918         else if (opts->nfs)
 919                 seq_puts(m, ",nfs=stale_rw");
 920         if (opts->discard)
 921                 seq_puts(m, ",discard");
 922         if (opts->dos1xfloppy)
 923                 seq_puts(m, ",dos1xfloppy");
 924
 925         return 0;
 926 }
 927
 928 enum {
 929         Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
 930         Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
 931         Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
 932         Opt_immutable, Opt_dots, Opt_nodots,
 933         Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
 934         Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
 935         Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
 936         Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
 937         Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
 938         Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
 939 };
 940
 941 static const match_table_t fat_tokens = {
 942         {Opt_check_r, "check=relaxed"},
 943         {Opt_check_s, "check=strict"},
 944         {Opt_check_n, "check=normal"},
 945         {Opt_check_r, "check=r"},
 946         {Opt_check_s, "check=s"},
 947         {Opt_check_n, "check=n"},
 948         {Opt_uid, "uid=%u"},
 949         {Opt_gid, "gid=%u"},
 950         {Opt_umask, "umask=%o"},
 951         {Opt_dmask, "dmask=%o"},
 952         {Opt_fmask, "fmask=%o"},
 953         {Opt_allow_utime, "allow_utime=%o"},
 954         {Opt_codepage, "codepage=%u"},
 955         {Opt_usefree, "usefree"},
 956         {Opt_nocase, "nocase"},
 957         {Opt_quiet, "quiet"},
 958         {Opt_showexec, "showexec"},
 959         {Opt_debug, "debug"},
 960         {Opt_immutable, "sys_immutable"},
 961         {Opt_flush, "flush"},
 962         {Opt_tz_utc, "tz=UTC"},
 963         {Opt_time_offset, "time_offset=%d"},
 964         {Opt_err_cont, "errors=continue"},
 965         {Opt_err_panic, "errors=panic"},
 966         {Opt_err_ro, "errors=remount-ro"},
 967         {Opt_discard, "discard"},
 968         {Opt_nfs_stale_rw, "nfs"},
 969         {Opt_nfs_stale_rw, "nfs=stale_rw"},
 970         {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
 971         {Opt_dos1xfloppy, "dos1xfloppy"},
 972         {Opt_obsolete, "conv=binary"},
 973         {Opt_obsolete, "conv=text"},
 974         {Opt_obsolete, "conv=auto"},
 975         {Opt_obsolete, "conv=b"},
 976         {Opt_obsolete, "conv=t"},
 977         {Opt_obsolete, "conv=a"},
 978         {Opt_obsolete, "fat=%u"},
 979         {Opt_obsolete, "blocksize=%u"},
 980         {Opt_obsolete, "cvf_format=%20s"},
 981         {Opt_obsolete, "cvf_options=%100s"},
 982         {Opt_obsolete, "posix"},
 983         {Opt_err, NULL},
 984 };
 985 static const match_table_t msdos_tokens = {
 986         {Opt_nodots, "nodots"},
 987         {Opt_nodots, "dotsOK=no"},
 988         {Opt_dots, "dots"},
 989         {Opt_dots, "dotsOK=yes"},
 990         {Opt_err, NULL}
 991 };
 992 static const match_table_t vfat_tokens = {
 993         {Opt_charset, "iocharset=%s"},
 994         {Opt_shortname_lower, "shortname=lower"},
 995         {Opt_shortname_win95, "shortname=win95"},
 996         {Opt_shortname_winnt, "shortname=winnt"},
 997         {Opt_shortname_mixed, "shortname=mixed"},
 998         {Opt_utf8_no, "utf8=0"},                /* 0 or no or false */
 999         {Opt_utf8_no, "utf8=no"},
1000         {Opt_utf8_no, "utf8=false"},
1001         {Opt_utf8_yes, "utf8=1"},               /* empty or 1 or yes or true */
1002         {Opt_utf8_yes, "utf8=yes"},
1003         {Opt_utf8_yes, "utf8=true"},
1004         {Opt_utf8_yes, "utf8"},
1005         {Opt_uni_xl_no, "uni_xlate=0"},         /* 0 or no or false */
1006         {Opt_uni_xl_no, "uni_xlate=no"},
1007         {Opt_uni_xl_no, "uni_xlate=false"},
1008         {Opt_uni_xl_yes, "uni_xlate=1"},        /* empty or 1 or yes or true */
1009         {Opt_uni_xl_yes, "uni_xlate=yes"},
1010         {Opt_uni_xl_yes, "uni_xlate=true"},
1011         {Opt_uni_xl_yes, "uni_xlate"},
1012         {Opt_nonumtail_no, "nonumtail=0"},      /* 0 or no or false */
1013         {Opt_nonumtail_no, "nonumtail=no"},
1014         {Opt_nonumtail_no, "nonumtail=false"},
1015         {Opt_nonumtail_yes, "nonumtail=1"},     /* empty or 1 or yes or true */
1016         {Opt_nonumtail_yes, "nonumtail=yes"},
1017         {Opt_nonumtail_yes, "nonumtail=true"},
1018         {Opt_nonumtail_yes, "nonumtail"},
1019         {Opt_rodir, "rodir"},
1020         {Opt_err, NULL}
1021 };
1022
1023 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1024                          int silent, int *debug, struct fat_mount_options *opts)
1025 {
1026         char *p;
1027         substring_t args[MAX_OPT_ARGS];
1028         int option;
1029         char *iocharset;
1030
1031         opts->isvfat = is_vfat;
1032
1033         opts->fs_uid = current_uid();
1034         opts->fs_gid = current_gid();
1035         opts->fs_fmask = opts->fs_dmask = current_umask();
1036         opts->allow_utime = -1;
1037         opts->codepage = fat_default_codepage;
1038         opts->iocharset = fat_default_iocharset;
1039         if (is_vfat) {
1040                 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1041                 opts->rodir = 0;
1042         } else {
1043                 opts->shortname = 0;
1044                 opts->rodir = 1;
1045         }
1046         opts->name_check = 'n';
1047         opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
1048         opts->utf8 = opts->unicode_xlate = 0;
1049         opts->numtail = 1;
1050         opts->usefree = opts->nocase = 0;
1051         opts->tz_set = 0;
1052         opts->nfs = 0;
1053         opts->errors = FAT_ERRORS_RO;
1054         *debug = 0;
1055
1056         if (!options)
1057                 goto out;
1058
1059         while ((p = strsep(&options, ",")) != NULL) {
1060                 int token;
1061                 if (!*p)
1062                         continue;
1063
1064                 token = match_token(p, fat_tokens, args);
1065                 if (token == Opt_err) {
1066                         if (is_vfat)
1067                                 token = match_token(p, vfat_tokens, args);
1068                         else
1069                                 token = match_token(p, msdos_tokens, args);
1070                 }
1071                 switch (token) {
1072                 case Opt_check_s:
1073                         opts->name_check = 's';
1074                         break;
1075                 case Opt_check_r:
1076                         opts->name_check = 'r';
1077                         break;
1078                 case Opt_check_n:
1079                         opts->name_check = 'n';
1080                         break;
1081                 case Opt_usefree:
1082                         opts->usefree = 1;
1083                         break;
1084                 case Opt_nocase:
1085                         if (!is_vfat)
1086                                 opts->nocase = 1;
1087                         else {
1088                                 /* for backward compatibility */
1089                                 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1090                                         | VFAT_SFN_CREATE_WIN95;
1091                         }
1092                         break;
1093                 case Opt_quiet:
1094                         opts->quiet = 1;
1095                         break;
1096                 case Opt_showexec:
1097                         opts->showexec = 1;
1098                         break;
1099                 case Opt_debug:
1100                         *debug = 1;
1101                         break;
1102                 case Opt_immutable:
1103                         opts->sys_immutable = 1;
1104                         break;
1105                 case Opt_uid:
1106                         if (match_int(&args[0], &option))
1107                                 return -EINVAL;
1108                         opts->fs_uid = make_kuid(current_user_ns(), option);
1109                         if (!uid_valid(opts->fs_uid))
1110                                 return -EINVAL;
1111                         break;
1112                 case Opt_gid:
1113                         if (match_int(&args[0], &option))
1114                                 return -EINVAL;
1115                         opts->fs_gid = make_kgid(current_user_ns(), option);
1116                         if (!gid_valid(opts->fs_gid))
1117                                 return -EINVAL;
1118                         break;
1119                 case Opt_umask:
1120                         if (match_octal(&args[0], &option))
1121                                 return -EINVAL;
1122                         opts->fs_fmask = opts->fs_dmask = option;
1123                         break;
1124                 case Opt_dmask:
1125                         if (match_octal(&args[0], &option))
1126                                 return -EINVAL;
1127                         opts->fs_dmask = option;
1128                         break;
1129                 case Opt_fmask:
1130                         if (match_octal(&args[0], &option))
1131                                 return -EINVAL;
1132                         opts->fs_fmask = option;
1133                         break;
1134                 case Opt_allow_utime:
1135                         if (match_octal(&args[0], &option))
1136                                 return -EINVAL;
1137                         opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1138                         break;
1139                 case Opt_codepage:
1140                         if (match_int(&args[0], &option))
1141                                 return -EINVAL;
1142                         opts->codepage = option;
1143                         break;
1144                 case Opt_flush:
1145                         opts->flush = 1;
1146                         break;
1147                 case Opt_time_offset:
1148                         if (match_int(&args[0], &option))
1149                                 return -EINVAL;
1150                         if (option < -12 * 60 || option > 12 * 60)
1151                                 return -EINVAL;
1152                         opts->tz_set = 1;
1153                         opts->time_offset = option;
1154                         break;
1155                 case Opt_tz_utc:
1156                         opts->tz_set = 1;
1157                         opts->time_offset = 0;
1158                         break;
1159                 case Opt_err_cont:
1160                         opts->errors = FAT_ERRORS_CONT;
1161                         break;
1162                 case Opt_err_panic:
1163                         opts->errors = FAT_ERRORS_PANIC;
1164                         break;
1165                 case Opt_err_ro:
1166                         opts->errors = FAT_ERRORS_RO;
1167                         break;
1168                 case Opt_nfs_stale_rw:
1169                         opts->nfs = FAT_NFS_STALE_RW;
1170                         break;
1171                 case Opt_nfs_nostale_ro:
1172                         opts->nfs = FAT_NFS_NOSTALE_RO;
1173                         break;
1174                 case Opt_dos1xfloppy:
1175                         opts->dos1xfloppy = 1;
1176                         break;
1177
1178                 /* msdos specific */
1179                 case Opt_dots:
1180                         opts->dotsOK = 1;
1181                         break;
1182                 case Opt_nodots:
1183                         opts->dotsOK = 0;
1184                         break;
1185
1186                 /* vfat specific */
1187                 case Opt_charset:
1188                         if (opts->iocharset != fat_default_iocharset)
1189                                 kfree(opts->iocharset);
1190                         iocharset = match_strdup(&args[0]);
1191                         if (!iocharset)
1192                                 return -ENOMEM;
1193                         opts->iocharset = iocharset;
1194                         break;
1195                 case Opt_shortname_lower:
1196                         opts->shortname = VFAT_SFN_DISPLAY_LOWER
1197                                         | VFAT_SFN_CREATE_WIN95;
1198                         break;
1199                 case Opt_shortname_win95:
1200                         opts->shortname = VFAT_SFN_DISPLAY_WIN95
1201                                         | VFAT_SFN_CREATE_WIN95;
1202                         break;
1203                 case Opt_shortname_winnt:
1204                         opts->shortname = VFAT_SFN_DISPLAY_WINNT
1205                                         | VFAT_SFN_CREATE_WINNT;
1206                         break;
1207                 case Opt_shortname_mixed:
1208                         opts->shortname = VFAT_SFN_DISPLAY_WINNT
1209                                         | VFAT_SFN_CREATE_WIN95;
1210                         break;
1211                 case Opt_utf8_no:               /* 0 or no or false */
1212                         opts->utf8 = 0;
1213                         break;
1214                 case Opt_utf8_yes:              /* empty or 1 or yes or true */
1215                         opts->utf8 = 1;
1216                         break;
1217                 case Opt_uni_xl_no:             /* 0 or no or false */
1218                         opts->unicode_xlate = 0;
1219                         break;
1220                 case Opt_uni_xl_yes:            /* empty or 1 or yes or true */
1221                         opts->unicode_xlate = 1;
1222                         break;
1223                 case Opt_nonumtail_no:          /* 0 or no or false */
1224                         opts->numtail = 1;      /* negated option */
1225                         break;
1226                 case Opt_nonumtail_yes:         /* empty or 1 or yes or true */
1227                         opts->numtail = 0;      /* negated option */
1228                         break;
1229                 case Opt_rodir:
1230                         opts->rodir = 1;
1231                         break;
1232                 case Opt_discard:
1233                         opts->discard = 1;
1234                         break;
1235
1236                 /* obsolete mount options */
1237                 case Opt_obsolete:
1238                         fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1239                                "not supported now", p);
1240                         break;
1241                 /* unknown option */
1242                 default:
1243                         if (!silent) {
1244                                 fat_msg(sb, KERN_ERR,
1245                                        "Unrecognized mount option \"%s\" "
1246                                        "or missing value", p);
1247                         }
1248                         return -EINVAL;
1249                 }
1250         }
1251
1252 out:
1253         /* UTF-8 doesn't provide FAT semantics */
1254         if (!strcmp(opts->iocharset, "utf8")) {
1255                 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1256                        " for FAT filesystems, filesystem will be "
1257                        "case sensitive!");
1258         }
1259
1260         /* If user doesn't specify allow_utime, it's initialized from dmask. */
1261         if (opts->allow_utime == (unsigned short)-1)
1262                 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1263         if (opts->unicode_xlate)
1264                 opts->utf8 = 0;
1265         if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1266                 sb->s_flags |= MS_RDONLY;
1267                 sb->s_export_op = &fat_export_ops_nostale;
1268         }
1269
1270         return 0;
1271 }
1272
1273 static int fat_read_root(struct inode *inode)
1274 {
1275         struct super_block *sb = inode->i_sb;
1276         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1277         int error;
1278
1279         MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1280         inode->i_uid = sbi->options.fs_uid;
1281         inode->i_gid = sbi->options.fs_gid;
1282         inode->i_version++;
1283         inode->i_generation = 0;
1284         inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1285         inode->i_op = sbi->dir_ops;
1286         inode->i_fop = &fat_dir_operations;
1287         if (sbi->fat_bits == 32) {
1288                 MSDOS_I(inode)->i_start = sbi->root_cluster;
1289                 error = fat_calc_dir_size(inode);
1290                 if (error < 0)
1291                         return error;
1292         } else {
1293                 MSDOS_I(inode)->i_start = 0;
1294                 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1295         }
1296         inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1297                            & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1298         MSDOS_I(inode)->i_logstart = 0;
1299         MSDOS_I(inode)->mmu_private = inode->i_size;
1300         MSDOS_I(inode)->i_disksize = inode->i_size;
1301
1302         fat_save_attrs(inode, ATTR_DIR);
1303         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1304         inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1305         set_nlink(inode, fat_subdirs(inode)+2);
1306
1307         return 0;
1308 }
1309
1310 static unsigned long calc_fat_clusters(struct super_block *sb)
1311 {
1312         struct msdos_sb_info *sbi = MSDOS_SB(sb);
1313
1314         /* Divide first to avoid overflow */
1315         if (sbi->fat_bits != 12) {
1316                 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1317                 return ent_per_sec * sbi->fat_length;
1318         }
1319
1320         return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1321 }
1322
1323 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1324 {
1325         if (get_unaligned_le16(&b->sector_size))
1326                 return false;
1327         if (b->sec_per_clus)
1328                 return false;
1329         if (b->reserved)
1330                 return false;
1331         if (b->fats)
1332                 return false;
1333         if (get_unaligned_le16(&b->dir_entries))
1334                 return false;
1335         if (get_unaligned_le16(&b->sectors))
1336                 return false;
1337         if (b->media)
1338                 return false;
1339         if (b->fat_length)
1340                 return false;
1341         if (b->secs_track)
1342                 return false;
1343         if (b->heads)
1344                 return false;
1345         return true;
1346 }
1347
1348 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1349         int silent, struct fat_bios_param_block *bpb)
1350 {
1351         int error = -EINVAL;
1352
1353         /* Read in BPB ... */
1354         memset(bpb, 0, sizeof(*bpb));
1355         bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1356         bpb->fat_sec_per_clus = b->sec_per_clus;
1357         bpb->fat_reserved = le16_to_cpu(b->reserved);
1358         bpb->fat_fats = b->fats;
1359         bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1360         bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1361         bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1362         bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1363
1364         bpb->fat16_state = b->fat16.state;
1365         bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1366
1367         bpb->fat32_length = le32_to_cpu(b->fat32.length);
1368         bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1369         bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1370         bpb->fat32_state = b->fat32.state;
1371         bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1372
1373         /* Validate this looks like a FAT filesystem BPB */
1374         if (!bpb->fat_reserved) {
1375                 if (!silent)
1376                         fat_msg(sb, KERN_ERR,
1377                                 "bogus number of reserved sectors");
1378                 goto out;
1379         }
1380         if (!bpb->fat_fats) {
1381                 if (!silent)
1382                         fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1383                 goto out;
1384         }
1385
1386         /*
1387          * Earlier we checked here that b->secs_track and b->head are nonzero,
1388          * but it turns out valid FAT filesystems can have zero there.
1389          */
1390
1391         if (!fat_valid_media(b->media)) {
1392                 if (!silent)
1393                         fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1394                                 (unsigned)b->media);
1395                 goto out;
1396         }
1397
1398         if (!is_power_of_2(bpb->fat_sector_size)
1399             || (bpb->fat_sector_size < 512)
1400             || (bpb->fat_sector_size > 4096)) {
1401                 if (!silent)
1402                         fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1403                                (unsigned)bpb->fat_sector_size);
1404                 goto out;
1405         }
1406
1407         if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1408                 if (!silent)
1409                         fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1410                                 (unsigned)bpb->fat_sec_per_clus);
1411                 goto out;
1412         }
1413
1414         error = 0;
1415
1416 out:
1417         return error;
1418 }
1419
1420 static int fat_read_static_bpb(struct super_block *sb,
1421         struct fat_boot_sector *b, int silent,
1422         struct fat_bios_param_block *bpb)
1423 {
1424         static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1425
1426         struct fat_floppy_defaults *fdefaults = NULL;
1427         int error = -EINVAL;
1428         sector_t bd_sects;
1429         unsigned i;
1430
1431         bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1432
1433         /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1434         if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1435                 if (!silent)
1436                         fat_msg(sb, KERN_ERR,
1437                                 "%s; no bootstrapping code", notdos1x);
1438                 goto out;
1439         }
1440
1441         /*
1442          * If any value in this region is non-zero, it isn't archaic
1443          * DOS.
1444          */
1445         if (!fat_bpb_is_zero(b)) {
1446                 if (!silent)
1447                         fat_msg(sb, KERN_ERR,
1448                                 "%s; DOS 2.x BPB is non-zero", notdos1x);
1449                 goto out;
1450         }
1451
1452         for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1453                 if (floppy_defaults[i].nr_sectors == bd_sects) {
1454                         fdefaults = &floppy_defaults[i];
1455                         break;
1456                 }
1457         }
1458
1459         if (fdefaults == NULL) {
1460                 if (!silent)
1461                         fat_msg(sb, KERN_WARNING,
1462                                 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1463                                 (u64)bd_sects);
1464                 goto out;
1465         }
1466
1467         if (!silent)
1468                 fat_msg(sb, KERN_INFO,
1469                         "This looks like a DOS 1.x volume; assuming default BPB values");
1470
1471         memset(bpb, 0, sizeof(*bpb));
1472         bpb->fat_sector_size = SECTOR_SIZE;
1473         bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1474         bpb->fat_reserved = 1;
1475         bpb->fat_fats = 2;
1476         bpb->fat_dir_entries = fdefaults->dir_entries;
1477         bpb->fat_sectors = fdefaults->nr_sectors;
1478         bpb->fat_fat_length = fdefaults->fat_length;
1479
1480         error = 0;
1481
1482 out:
1483         return error;
1484 }
1485
1486 /*
1487  * Read the super block of an MS-DOS FS.
1488  */
1489 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1490                    void (*setup)(struct super_block *))
1491 {
1492         struct inode *root_inode = NULL, *fat_inode = NULL;
1493         struct inode *fsinfo_inode = NULL;
1494         struct buffer_head *bh;
1495         struct fat_bios_param_block bpb;
1496         struct msdos_sb_info *sbi;
1497         u16 logical_sector_size;
1498         u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1499         int debug;
1500         long error;
1501         char buf[50];
1502
1503         /*
1504          * GFP_KERNEL is ok here, because while we do hold the
1505          * supeblock lock, memory pressure can't call back into
1506          * the filesystem, since we're only just about to mount
1507          * it and have no inodes etc active!
1508          */
1509         sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1510         if (!sbi)
1511                 return -ENOMEM;
1512         sb->s_fs_info = sbi;
1513
1514         sb->s_flags |= MS_NODIRATIME;
1515         sb->s_magic = MSDOS_SUPER_MAGIC;
1516         sb->s_op = &fat_sops;
1517         sb->s_export_op = &fat_export_ops;
1518         mutex_init(&sbi->nfs_build_inode_lock);
1519         ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1520                              DEFAULT_RATELIMIT_BURST);
1521
1522         error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1523         if (error)
1524                 goto out_fail;
1525
1526         setup(sb); /* flavour-specific stuff that needs options */
1527
1528         error = -EIO;
1529         sb_min_blocksize(sb, 512);
1530         bh = sb_bread(sb, 0);
1531         if (bh == NULL) {
1532                 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1533                 goto out_fail;
1534         }
1535
1536         error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1537                 &bpb);
1538         if (error == -EINVAL && sbi->options.dos1xfloppy)
1539                 error = fat_read_static_bpb(sb,
1540                         (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1541         brelse(bh);
1542
1543         if (error == -EINVAL)
1544                 goto out_invalid;
1545         else if (error)
1546                 goto out_fail;
1547
1548         logical_sector_size = bpb.fat_sector_size;
1549         sbi->sec_per_clus = bpb.fat_sec_per_clus;
1550
1551         error = -EIO;
1552         if (logical_sector_size < sb->s_blocksize) {
1553                 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1554                        " (logical sector size = %u)", logical_sector_size);
1555                 goto out_fail;
1556         }
1557
1558         if (logical_sector_size > sb->s_blocksize) {
1559                 struct buffer_head *bh_resize;
1560
1561                 if (!sb_set_blocksize(sb, logical_sector_size)) {
1562                         fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1563                                logical_sector_size);
1564                         goto out_fail;
1565                 }
1566
1567                 /* Verify that the larger boot sector is fully readable */
1568                 bh_resize = sb_bread(sb, 0);
1569                 if (bh_resize == NULL) {
1570                         fat_msg(sb, KERN_ERR, "unable to read boot sector"
1571                                " (logical sector size = %lu)",
1572                                sb->s_blocksize);
1573                         goto out_fail;
1574                 }
1575                 brelse(bh_resize);
1576         }
1577
1578         mutex_init(&sbi->s_lock);
1579         sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1580         sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1581         sbi->fats = bpb.fat_fats;
1582         sbi->fat_bits = 0;              /* Don't know yet */
1583         sbi->fat_start = bpb.fat_reserved;
1584         sbi->fat_length = bpb.fat_fat_length;
1585         sbi->root_cluster = 0;
1586         sbi->free_clusters = -1;        /* Don't know yet */
1587         sbi->free_clus_valid = 0;
1588         sbi->prev_free = FAT_START_ENT;
1589         sb->s_maxbytes = 0xffffffff;
1590
1591         if (!sbi->fat_length && bpb.fat32_length) {
1592                 struct fat_boot_fsinfo *fsinfo;
1593                 struct buffer_head *fsinfo_bh;
1594
1595                 /* Must be FAT32 */
1596                 sbi->fat_bits = 32;
1597                 sbi->fat_length = bpb.fat32_length;
1598                 sbi->root_cluster = bpb.fat32_root_cluster;
1599
1600                 /* MC - if info_sector is 0, don't multiply by 0 */
1601                 sbi->fsinfo_sector = bpb.fat32_info_sector;
1602                 if (sbi->fsinfo_sector == 0)
1603                         sbi->fsinfo_sector = 1;
1604
1605                 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1606                 if (fsinfo_bh == NULL) {
1607                         fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1608                                " (sector = %lu)", sbi->fsinfo_sector);
1609                         goto out_fail;
1610                 }
1611
1612                 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1613                 if (!IS_FSINFO(fsinfo)) {
1614                         fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1615                                "0x%08x, 0x%08x (sector = %lu)",
1616                                le32_to_cpu(fsinfo->signature1),
1617                                le32_to_cpu(fsinfo->signature2),
1618                                sbi->fsinfo_sector);
1619                 } else {
1620                         if (sbi->options.usefree)
1621                                 sbi->free_clus_valid = 1;
1622                         sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1623                         sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1624                 }
1625
1626                 brelse(fsinfo_bh);
1627         }
1628
1629         /* interpret volume ID as a little endian 32 bit integer */
1630         if (sbi->fat_bits == 32)
1631                 sbi->vol_id = bpb.fat32_vol_id;
1632         else /* fat 16 or 12 */
1633                 sbi->vol_id = bpb.fat16_vol_id;
1634
1635         sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1636         sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1637
1638         sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1639         sbi->dir_entries = bpb.fat_dir_entries;
1640         if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1641                 if (!silent)
1642                         fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
1643                                " (%u)", sbi->dir_entries);
1644                 goto out_invalid;
1645         }
1646
1647         rootdir_sectors = sbi->dir_entries
1648                 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1649         sbi->data_start = sbi->dir_start + rootdir_sectors;
1650         total_sectors = bpb.fat_sectors;
1651         if (total_sectors == 0)
1652                 total_sectors = bpb.fat_total_sect;
1653
1654         total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1655
1656         if (sbi->fat_bits != 32)
1657                 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1658
1659         /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1660         if (sbi->fat_bits == 32)
1661                 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1662         else /* fat 16 or 12 */
1663                 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1664
1665         /* check that FAT table does not overflow */
1666         fat_clusters = calc_fat_clusters(sb);
1667         total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1668         if (total_clusters > MAX_FAT(sb)) {
1669                 if (!silent)
1670                         fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1671                                total_clusters);
1672                 goto out_invalid;
1673         }
1674
1675         sbi->max_cluster = total_clusters + FAT_START_ENT;
1676         /* check the free_clusters, it's not necessarily correct */
1677         if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1678                 sbi->free_clusters = -1;
1679         /* check the prev_free, it's not necessarily correct */
1680         sbi->prev_free %= sbi->max_cluster;
1681         if (sbi->prev_free < FAT_START_ENT)
1682                 sbi->prev_free = FAT_START_ENT;
1683
1684         /* set up enough so that it can read an inode */
1685         fat_hash_init(sb);
1686         dir_hash_init(sb);
1687         fat_ent_access_init(sb);
1688
1689         /*
1690          * The low byte of FAT's first entry must have same value with
1691          * media-field.  But in real world, too many devices is
1692          * writing wrong value.  So, removed that validity check.
1693          *
1694          * if (FAT_FIRST_ENT(sb, media) != first)
1695          */
1696
1697         error = -EINVAL;
1698         sprintf(buf, "cp%d", sbi->options.codepage);
1699         sbi->nls_disk = load_nls(buf);
1700         if (!sbi->nls_disk) {
1701                 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1702                 goto out_fail;
1703         }
1704
1705         /* FIXME: utf8 is using iocharset for upper/lower conversion */
1706         if (sbi->options.isvfat) {
1707                 sbi->nls_io = load_nls(sbi->options.iocharset);
1708                 if (!sbi->nls_io) {
1709                         fat_msg(sb, KERN_ERR, "IO charset %s not found",
1710                                sbi->options.iocharset);
1711                         goto out_fail;
1712                 }
1713         }
1714
1715         error = -ENOMEM;
1716         fat_inode = new_inode(sb);
1717         if (!fat_inode)
1718                 goto out_fail;
1719         MSDOS_I(fat_inode)->i_pos = 0;
1720         sbi->fat_inode = fat_inode;
1721
1722         fsinfo_inode = new_inode(sb);
1723         if (!fsinfo_inode)
1724                 goto out_fail;
1725         fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1726         sbi->fsinfo_inode = fsinfo_inode;
1727         insert_inode_hash(fsinfo_inode);
1728
1729         root_inode = new_inode(sb);
1730         if (!root_inode)
1731                 goto out_fail;
1732         root_inode->i_ino = MSDOS_ROOT_INO;
1733         root_inode->i_version = 1;
1734         error = fat_read_root(root_inode);
1735         if (error < 0) {
1736                 iput(root_inode);
1737                 goto out_fail;
1738         }
1739         error = -ENOMEM;
1740         insert_inode_hash(root_inode);
1741         fat_attach(root_inode, 0);
1742         sb->s_root = d_make_root(root_inode);
1743         if (!sb->s_root) {
1744                 fat_msg(sb, KERN_ERR, "get root inode failed");
1745                 goto out_fail;
1746         }
1747
1748         if (sbi->options.discard) {
1749                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1750                 if (!blk_queue_discard(q))
1751                         fat_msg(sb, KERN_WARNING,
1752                                         "mounting with \"discard\" option, but "
1753                                         "the device does not support discard");
1754         }
1755
1756         fat_set_state(sb, 1, 0);
1757         return 0;
1758
1759 out_invalid:
1760         error = -EINVAL;
1761         if (!silent)
1762                 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1763
1764 out_fail:
1765         if (fsinfo_inode)
1766                 iput(fsinfo_inode);
1767         if (fat_inode)
1768                 iput(fat_inode);
1769         unload_nls(sbi->nls_io);
1770         unload_nls(sbi->nls_disk);
1771         if (sbi->options.iocharset != fat_default_iocharset)
1772                 kfree(sbi->options.iocharset);
1773         sb->s_fs_info = NULL;
1774         kfree(sbi);
1775         return error;
1776 }
1777
1778 EXPORT_SYMBOL_GPL(fat_fill_super);
1779
1780 /*
1781  * helper function for fat_flush_inodes.  This writes both the inode
1782  * and the file data blocks, waiting for in flight data blocks before
1783  * the start of the call.  It does not wait for any io started
1784  * during the call
1785  */
1786 static int writeback_inode(struct inode *inode)
1787 {
1788
1789         int ret;
1790
1791         /* if we used wait=1, sync_inode_metadata waits for the io for the
1792         * inode to finish.  So wait=0 is sent down to sync_inode_metadata
1793         * and filemap_fdatawrite is used for the data blocks
1794         */
1795         ret = sync_inode_metadata(inode, 0);
1796         if (!ret)
1797                 ret = filemap_fdatawrite(inode->i_mapping);
1798         return ret;
1799 }
1800
1801 /*
1802  * write data and metadata corresponding to i1 and i2.  The io is
1803  * started but we do not wait for any of it to finish.
1804  *
1805  * filemap_flush is used for the block device, so if there is a dirty
1806  * page for a block already in flight, we will not wait and start the
1807  * io over again
1808  */
1809 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1810 {
1811         int ret = 0;
1812         if (!MSDOS_SB(sb)->options.flush)
1813                 return 0;
1814         if (i1)
1815                 ret = writeback_inode(i1);
1816         if (!ret && i2)
1817                 ret = writeback_inode(i2);
1818         if (!ret) {
1819                 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1820                 ret = filemap_flush(mapping);
1821         }
1822         return ret;
1823 }
1824 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1825
1826 static int __init init_fat_fs(void)
1827 {
1828         int err;
1829
1830         err = fat_cache_init();
1831         if (err)
1832                 return err;
1833
1834         err = fat_init_inodecache();
1835         if (err)
1836                 goto failed;
1837
1838         return 0;
1839
1840 failed:
1841         fat_cache_destroy();
1842         return err;
1843 }
1844
1845 static void __exit exit_fat_fs(void)
1846 {
1847         fat_cache_destroy();
1848         fat_destroy_inodecache();
1849 }
1850
1851 module_init(init_fat_fs)
1852 module_exit(exit_fat_fs)
1853
1854 MODULE_LICENSE("GPL");