LCOV - code coverage report
Current view: top level - lkbce/fs/fat - inode.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 434 914 47.5 %
Date: 2017-01-25 Functions: 38 46 82.6 %

          Line data    Source code
       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/smp_lock.h>
      18             : #include <linux/seq_file.h>
      19             : #include <linux/pagemap.h>
      20             : #include <linux/mpage.h>
      21             : #include <linux/buffer_head.h>
      22             : #include <linux/exportfs.h>
      23             : #include <linux/mount.h>
      24             : #include <linux/vfs.h>
      25             : #include <linux/parser.h>
      26             : #include <linux/uio.h>
      27             : #include <linux/writeback.h>
      28             : #include <linux/log2.h>
      29             : #include <linux/hash.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           1 : static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
      39           1 : static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
      40             : 
      41             : 
      42             : static int fat_add_cluster(struct inode *inode)
      43             : {
      44           0 :         int err, cluster;
      45           0 : 
      46           0 :         err = fat_alloc_clusters(inode, &cluster, 1);
      47           0 :         if (err)
      48           0 :                 return err;
      49             :         /* FIXME: this cluster should be added after data of this
      50             :          * cluster is writed */
      51           0 :         err = fat_chain_add(inode, cluster, 1);
      52           0 :         if (err)
      53           0 :                 fat_free_clusters(inode, cluster);
      54           0 :         return err;
      55             : }
      56             : 
      57             : static inline int __fat_get_block(struct inode *inode, sector_t iblock,
      58             :                                   unsigned long *max_blocks,
      59             :                                   struct buffer_head *bh_result, int create)
      60           0 : {
      61           0 :         struct super_block *sb = inode->i_sb;
      62           0 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
      63           0 :         unsigned long mapped_blocks;
      64           0 :         sector_t phys;
      65           0 :         int err, offset;
      66           0 : 
      67           0 :         err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
      68           0 :         if (err)
      69           0 :                 return err;
      70           0 :         if (phys) {
      71           0 :                 map_bh(bh_result, sb, phys);
      72           0 :                 *max_blocks = min(mapped_blocks, *max_blocks);
      73           0 :                 return 0;
      74           0 :         }
      75           0 :         if (!create)
      76           0 :                 return 0;
      77           0 : 
      78           0 :         if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
      79           0 :                 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
      80             :                         MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
      81           0 :                 return -EIO;
      82             :         }
      83             : 
      84           0 :         offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
      85           0 :         if (!offset) {
      86             :                 /* TODO: multiple cluster allocation would be desirable. */
      87           0 :                 err = fat_add_cluster(inode);
      88           0 :                 if (err)
      89           0 :                         return err;
      90             :         }
      91             :         /* available blocks on this cluster */
      92           0 :         mapped_blocks = sbi->sec_per_clus - offset;
      93             : 
      94           0 :         *max_blocks = min(mapped_blocks, *max_blocks);
      95           0 :         MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
      96             : 
      97           0 :         err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
      98           0 :         if (err)
      99           0 :                 return err;
     100             : 
     101           0 :         BUG_ON(!phys);
     102           0 :         BUG_ON(*max_blocks != mapped_blocks);
     103           0 :         set_buffer_new(bh_result);
     104           0 :         map_bh(bh_result, sb, phys);
     105             : 
     106           0 :         return 0;
     107             : }
     108             : 
     109             : static int fat_get_block(struct inode *inode, sector_t iblock,
     110             :                          struct buffer_head *bh_result, int create)
     111             : {
     112           0 :         struct super_block *sb = inode->i_sb;
     113           0 :         unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
     114           0 :         int err;
     115             : 
     116           0 :         err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
     117           0 :         if (err)
     118           0 :                 return err;
     119           0 :         bh_result->b_size = max_blocks << sb->s_blocksize_bits;
     120           0 :         return 0;
     121             : }
     122             : 
     123             : static int fat_writepage(struct page *page, struct writeback_control *wbc)
     124             : {
     125           3 :         return block_write_full_page(page, fat_get_block, wbc);
     126             : }
     127             : 
     128             : static int fat_writepages(struct address_space *mapping,
     129             :                           struct writeback_control *wbc)
     130           1 : {
     131           2 :         return mpage_writepages(mapping, wbc, fat_get_block);
     132             : }
     133             : 
     134             : static int fat_readpage(struct file *file, struct page *page)
     135             : {
     136           3 :         return mpage_readpage(page, fat_get_block);
     137             : }
     138             : 
     139             : static int fat_readpages(struct file *file, struct address_space *mapping,
     140             :                          struct list_head *pages, unsigned nr_pages)
     141             : {
     142           3 :         return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
     143             : }
     144             : 
     145             : static int fat_write_begin(struct file *file, struct address_space *mapping,
     146             :                         loff_t pos, unsigned len, unsigned flags,
     147             :                         struct page **pagep, void **fsdata)
     148             : {
     149           2 :         *pagep = NULL;
     150           5 :         return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
     151             :                                 fat_get_block,
     152             :                                 &MSDOS_I(mapping->host)->mmu_private);
     153             : }
     154             : 
     155             : static int fat_write_end(struct file *file, struct address_space *mapping,
     156             :                         loff_t pos, unsigned len, unsigned copied,
     157             :                         struct page *pagep, void *fsdata)
     158             : {
     159           2 :         struct inode *inode = mapping->host;
     160           1 :         int err;
     161           2 :         err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
     162           7 :         if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
     163           7 :                 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
     164           4 :                 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
     165           3 :                 mark_inode_dirty(inode);
     166             :         }
     167           3 :         return err;
     168             : }
     169             : 
     170             : static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
     171             :                              const struct iovec *iov,
     172             :                              loff_t offset, unsigned long nr_segs)
     173           1 : {
     174           2 :         struct file *file = iocb->ki_filp;
     175           2 :         struct inode *inode = file->f_mapping->host;
     176           1 : 
     177           3 :         if (rw == WRITE) {
     178           1 :                 /*
     179             :                  * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
     180             :                  * so we need to update the ->mmu_private to block boundary.
     181             :                  *
     182             :                  * But we must fill the remaining area or hole by nul for
     183             :                  * updating ->mmu_private.
     184             :                  *
     185             :                  * Return 0, and fallback to normal buffered write.
     186             :                  */
     187           3 :                 loff_t size = offset + iov_length(iov, nr_segs);
     188           4 :                 if (MSDOS_I(inode)->mmu_private < size)
     189           1 :                         return 0;
     190             :         }
     191             : 
     192             :         /*
     193             :          * FAT need to use the DIO_LOCKING for avoiding the race
     194             :          * condition of fat_get_block() and ->truncate().
     195             :          */
     196           5 :         return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
     197             :                                   offset, nr_segs, fat_get_block, NULL);
     198             : }
     199             : 
     200             : static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
     201             : {
     202           1 :         sector_t blocknr;
     203             : 
     204             :         /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
     205           1 :         down_read(&mapping->host->i_alloc_sem);
     206           1 :         blocknr = generic_block_bmap(mapping, block, fat_get_block);
     207           1 :         up_read(&mapping->host->i_alloc_sem);
     208             : 
     209           1 :         return blocknr;
     210             : }
     211             : 
     212           1 : static const struct address_space_operations fat_aops = {
     213             :         .readpage       = fat_readpage,
     214             :         .readpages      = fat_readpages,
     215             :         .writepage      = fat_writepage,
     216             :         .writepages     = fat_writepages,
     217             :         .sync_page      = block_sync_page,
     218             :         .write_begin    = fat_write_begin,
     219             :         .write_end      = fat_write_end,
     220             :         .direct_IO      = fat_direct_IO,
     221             :         .bmap           = _fat_bmap
     222             : };
     223             : 
     224             : /*
     225             :  * New FAT inode stuff. We do the following:
     226             :  *      a) i_ino is constant and has nothing with on-disk location.
     227             :  *      b) FAT manages its own cache of directory entries.
     228             :  *      c) *This* cache is indexed by on-disk location.
     229             :  *      d) inode has an associated directory entry, all right, but
     230             :  *              it may be unhashed.
     231             :  *      e) currently entries are stored within struct inode. That should
     232             :  *              change.
     233             :  *      f) we deal with races in the following way:
     234             :  *              1. readdir() and lookup() do FAT-dir-cache lookup.
     235             :  *              2. rename() unhashes the F-d-c entry and rehashes it in
     236             :  *                      a new place.
     237             :  *              3. unlink() and rmdir() unhash F-d-c entry.
     238             :  *              4. fat_write_inode() checks whether the thing is unhashed.
     239             :  *                      If it is we silently return. If it isn't we do bread(),
     240             :  *                      check if the location is still valid and retry if it
     241             :  *                      isn't. Otherwise we do changes.
     242             :  *              5. Spinlock is used to protect hash/unhash/location check/lookup
     243             :  *              6. fat_clear_inode() unhashes the F-d-c entry.
     244             :  *              7. lookup() and readdir() do igrab() if they find a F-d-c entry
     245             :  *                      and consider negative result as cache miss.
     246             :  */
     247             : 
     248             : static void fat_hash_init(struct super_block *sb)
     249             : {
     250           0 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
     251           0 :         int i;
     252           0 : 
     253           0 :         spin_lock_init(&sbi->inode_hash_lock);
     254           0 :         for (i = 0; i < FAT_HASH_SIZE; i++)
     255           0 :                 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
     256           0 : }
     257             : 
     258             : static inline unsigned long fat_hash(loff_t i_pos)
     259             : {
     260          24 :         return hash_32(i_pos, FAT_HASH_BITS);
     261           0 : }
     262             : 
     263             : void fat_attach(struct inode *inode, loff_t i_pos)
     264             : {
     265           4 :         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
     266           4 :         struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
     267           1 : 
     268           3 :         spin_lock(&sbi->inode_hash_lock);
     269           4 :         MSDOS_I(inode)->i_pos = i_pos;
     270           5 :         hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
     271           2 :         spin_unlock(&sbi->inode_hash_lock);
     272           1 : }
     273             : EXPORT_SYMBOL_GPL(fat_attach);
     274             : 
     275             : void fat_detach(struct inode *inode)
     276             : {
     277           4 :         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
     278           3 :         spin_lock(&sbi->inode_hash_lock);
     279           4 :         MSDOS_I(inode)->i_pos = 0;
     280           6 :         hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
     281           2 :         spin_unlock(&sbi->inode_hash_lock);
     282           1 : }
     283             : EXPORT_SYMBOL_GPL(fat_detach);
     284             : 
     285             : struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
     286             : {
     287          20 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
     288          20 :         struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
     289           5 :         struct hlist_node *_p;
     290           5 :         struct msdos_inode_info *i;
     291          10 :         struct inode *inode = NULL;
     292           5 : 
     293          15 :         spin_lock(&sbi->inode_hash_lock);
     294          50 :         hlist_for_each_entry(i, _p, head, i_fat_hash) {
     295          45 :                 BUG_ON(i->vfs_inode.i_sb != sb);
     296          15 :                 if (i->i_pos != i_pos)
     297           5 :                         continue;
     298           5 :                 inode = igrab(&i->vfs_inode);
     299          10 :                 if (inode)
     300          10 :                         break;
     301             :         }
     302          20 :         spin_unlock(&sbi->inode_hash_lock);
     303           5 :         return inode;
     304           5 : }
     305             : 
     306             : static int is_exec(unsigned char *extension)
     307             : {
     308           2 :         unsigned char *exe_extensions = "EXECOMBAT", *walk;
     309           1 : 
     310           6 :         for (walk = exe_extensions; *walk; walk += 3)
     311           5 :                 if (!strncmp(extension, walk, 3))
     312           2 :                         return 1;
     313           1 :         return 0;
     314             : }
     315             : 
     316             : static int fat_calc_dir_size(struct inode *inode)
     317             : {
     318           4 :         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
     319           1 :         int ret, fclus, dclus;
     320           1 : 
     321           2 :         inode->i_size = 0;
     322           5 :         if (MSDOS_I(inode)->i_start == 0)
     323           2 :                 return 0;
     324             : 
     325           3 :         ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
     326           2 :         if (ret < 0)
     327           1 :                 return ret;
     328           2 :         inode->i_size = (fclus + 1) << sbi->cluster_bits;
     329             : 
     330           1 :         return 0;
     331             : }
     332             : 
     333             : /* doesn't deal with root inode */
     334             : static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
     335             : {
     336           4 :         struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
     337           1 :         int error;
     338           1 : 
     339           4 :         MSDOS_I(inode)->i_pos = 0;
     340           2 :         inode->i_uid = sbi->options.fs_uid;
     341           2 :         inode->i_gid = sbi->options.fs_gid;
     342           2 :         inode->i_version++;
     343           3 :         inode->i_generation = get_seconds();
     344           1 : 
     345           8 :         if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
     346           2 :                 inode->i_generation &= ~1;
     347           5 :                 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
     348           3 :                 inode->i_op = sbi->dir_ops;
     349           2 :                 inode->i_fop = &fat_dir_operations;
     350           1 : 
     351           5 :                 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
     352           4 :                 if (sbi->fat_bits == 32)
     353           5 :                         MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
     354           1 : 
     355           8 :                 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
     356           4 :                 error = fat_calc_dir_size(inode);
     357           2 :                 if (error < 0)
     358           1 :                         return error;
     359           3 :                 MSDOS_I(inode)->mmu_private = inode->i_size;
     360             : 
     361           3 :                 inode->i_nlink = fat_subdirs(inode);
     362             :         } else { /* not a directory */
     363           1 :                 inode->i_generation |= 1;
     364          16 :                 inode->i_mode = fat_make_mode(sbi, de->attr,
     365             :                         ((sbi->options.showexec && !is_exec(de->name + 8))
     366             :                          ? S_IRUGO|S_IWUGO : S_IRWXUGO));
     367           4 :                 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
     368           3 :                 if (sbi->fat_bits == 32)
     369           4 :                         MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
     370             : 
     371           7 :                 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
     372           2 :                 inode->i_size = le32_to_cpu(de->size);
     373           1 :                 inode->i_op = &fat_file_inode_operations;
     374           1 :                 inode->i_fop = &fat_file_operations;
     375           1 :                 inode->i_mapping->a_ops = &fat_aops;
     376           3 :                 MSDOS_I(inode)->mmu_private = inode->i_size;
     377             :         }
     378           6 :         if (de->attr & ATTR_SYS) {
     379           4 :                 if (sbi->options.sys_immutable)
     380           2 :                         inode->i_flags |= S_IMMUTABLE;
     381             :         }
     382           8 :         fat_save_attrs(inode, de->attr);
     383             : 
     384           2 :         inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
     385             :                            & ~((loff_t)sbi->cluster_size - 1)) >> 9;
     386             : 
     387           4 :         fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
     388           2 :         if (sbi->options.isvfat) {
     389           5 :                 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
     390             :                                   de->cdate, de->ctime_cs);
     391           3 :                 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
     392             :         } else
     393           3 :                 inode->i_ctime = inode->i_atime = inode->i_mtime;
     394             : 
     395           2 :         return 0;
     396             : }
     397             : 
     398             : struct inode *fat_build_inode(struct super_block *sb,
     399             :                         struct msdos_dir_entry *de, loff_t i_pos)
     400             : {
     401           1 :         struct inode *inode;
     402           1 :         int err;
     403           1 : 
     404           3 :         inode = fat_iget(sb, i_pos);
     405           2 :         if (inode)
     406           1 :                 goto out;
     407           1 :         inode = new_inode(sb);
     408           2 :         if (!inode) {
     409           3 :                 inode = ERR_PTR(-ENOMEM);
     410           1 :                 goto out;
     411             :         }
     412           1 :         inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
     413           1 :         inode->i_version = 1;
     414           4 :         err = fat_fill_inode(inode, de);
     415           2 :         if (err) {
     416           1 :                 iput(inode);
     417           3 :                 inode = ERR_PTR(err);
     418           1 :                 goto out;
     419             :         }
     420           2 :         fat_attach(inode, i_pos);
     421           2 :         insert_inode_hash(inode);
     422             : out:
     423           5 :         return inode;
     424             : }
     425             : 
     426             : EXPORT_SYMBOL_GPL(fat_build_inode);
     427             : 
     428             : static void fat_delete_inode(struct inode *inode)
     429             : {
     430           1 :         truncate_inode_pages(&inode->i_data, 0);
     431           1 :         inode->i_size = 0;
     432           2 :         fat_truncate(inode);
     433           1 :         clear_inode(inode);
     434           1 : }
     435             : 
     436             : static void fat_clear_inode(struct inode *inode)
     437             : {
     438           2 :         fat_cache_inval_inode(inode);
     439           2 :         fat_detach(inode);
     440           1 : }
     441             : 
     442             : static void fat_write_super(struct super_block *sb)
     443             : {
     444           2 :         lock_super(sb);
     445           2 :         sb->s_dirt = 0;
     446             : 
     447           4 :         if (!(sb->s_flags & MS_RDONLY))
     448           8 :                 fat_clusters_flush(sb);
     449           4 :         unlock_super(sb);
     450           4 : }
     451             : 
     452             : static int fat_sync_fs(struct super_block *sb, int wait)
     453             : {
     454           2 :         int err = 0;
     455             : 
     456           3 :         if (sb->s_dirt) {
     457           1 :                 lock_super(sb);
     458           1 :                 sb->s_dirt = 0;
     459           4 :                 err = fat_clusters_flush(sb);
     460           1 :                 unlock_super(sb);
     461             :         }
     462             : 
     463           2 :         return err;
     464             : }
     465             : 
     466             : static void fat_put_super(struct super_block *sb)
     467             : {
     468           4 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
     469           1 : 
     470           1 :         lock_kernel();
     471             : 
     472           3 :         if (sb->s_dirt)
     473           3 :                 fat_write_super(sb);
     474             : 
     475           2 :         iput(sbi->fat_inode);
     476             : 
     477           2 :         unload_nls(sbi->nls_disk);
     478           2 :         unload_nls(sbi->nls_io);
     479             : 
     480           4 :         if (sbi->options.iocharset != fat_default_iocharset)
     481           2 :                 kfree(sbi->options.iocharset);
     482             : 
     483           2 :         sb->s_fs_info = NULL;
     484           2 :         kfree(sbi);
     485             : 
     486           2 :         unlock_kernel();
     487           2 : }
     488             : 
     489           1 : static struct kmem_cache *fat_inode_cachep;
     490             : 
     491             : static struct inode *fat_alloc_inode(struct super_block *sb)
     492             : {
     493           1 :         struct msdos_inode_info *ei;
     494           3 :         ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
     495           2 :         if (!ei)
     496           1 :                 return NULL;
     497           1 :         return &ei->vfs_inode;
     498             : }
     499             : 
     500             : static void fat_destroy_inode(struct inode *inode)
     501             : {
     502           4 :         kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
     503           1 : }
     504             : 
     505             : static void init_once(void *foo)
     506             : {
     507           0 :         struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
     508           0 : 
     509           0 :         spin_lock_init(&ei->cache_lru_lock);
     510           0 :         ei->nr_caches = 0;
     511           0 :         ei->cache_valid_id = FAT_CACHE_VALID + 1;
     512           0 :         INIT_LIST_HEAD(&ei->cache_lru);
     513           0 :         INIT_HLIST_NODE(&ei->i_fat_hash);
     514           0 :         inode_init_once(&ei->vfs_inode);
     515           0 : }
     516             : 
     517             : static int __init fat_init_inodecache(void)
     518             : {
     519           1 :         fat_inode_cachep = kmem_cache_create("fat_inode_cache",
     520             :                                              sizeof(struct msdos_inode_info),
     521             :                                              0, (SLAB_RECLAIM_ACCOUNT|
     522             :                                                 SLAB_MEM_SPREAD),
     523             :                                              init_once);
     524           2 :         if (fat_inode_cachep == NULL)
     525           1 :                 return -ENOMEM;
     526           1 :         return 0;
     527             : }
     528             : 
     529             : static void __exit fat_destroy_inodecache(void)
     530             : {
     531           2 :         kmem_cache_destroy(fat_inode_cachep);
     532           2 : }
     533             : 
     534             : static int fat_remount(struct super_block *sb, int *flags, char *data)
     535             : {
     536           4 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
     537           7 :         *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
     538           1 :         return 0;
     539             : }
     540             : 
     541             : static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
     542             : {
     543           2 :         struct super_block *sb = dentry->d_sb;
     544           4 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
     545           4 :         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
     546           1 : 
     547           1 :         /* If the count of free cluster is still unknown, counts it here. */
     548           5 :         if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
     549           4 :                 int err = fat_count_free_clusters(dentry->d_sb);
     550           2 :                 if (err)
     551           1 :                         return err;
     552             :         }
     553             : 
     554           4 :         buf->f_type = dentry->d_sb->s_magic;
     555           4 :         buf->f_bsize = sbi->cluster_size;
     556           2 :         buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
     557           4 :         buf->f_bfree = sbi->free_clusters;
     558           4 :         buf->f_bavail = sbi->free_clusters;
     559           2 :         buf->f_fsid.val[0] = (u32)id;
     560           2 :         buf->f_fsid.val[1] = (u32)(id >> 32);
     561          12 :         buf->f_namelen = sbi->options.isvfat ? 260 : 12;
     562             : 
     563           2 :         return 0;
     564             : }
     565             : 
     566             : static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
     567             :                                     struct inode *inode)
     568           5 : {
     569           5 :         loff_t i_pos;
     570             : #if BITS_PER_LONG == 32
     571             :         spin_lock(&sbi->inode_hash_lock);
     572             : #endif
     573          15 :         i_pos = MSDOS_I(inode)->i_pos;
     574             : #if BITS_PER_LONG == 32
     575             :         spin_unlock(&sbi->inode_hash_lock);
     576             : #endif
     577           5 :         return i_pos;
     578             : }
     579             : 
     580             : static int fat_write_inode(struct inode *inode, int wait)
     581             : {
     582          10 :         struct super_block *sb = inode->i_sb;
     583          20 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
     584           5 :         struct buffer_head *bh;
     585           5 :         struct msdos_dir_entry *raw_entry;
     586           5 :         loff_t i_pos;
     587           5 :         int err;
     588           5 : 
     589          15 :         if (inode->i_ino == MSDOS_ROOT_INO)
     590          10 :                 return 0;
     591           5 : 
     592           5 : retry:
     593          10 :         i_pos = fat_i_pos_read(sbi, inode);
     594          15 :         if (!i_pos)
     595           5 :                 return 0;
     596             : 
     597          10 :         bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
     598          10 :         if (!bh) {
     599           5 :                 printk(KERN_ERR "FAT: unable to read inode block "
     600             :                        "for updating (i_pos %lld)\n", i_pos);
     601           5 :                 return -EIO;
     602             :         }
     603          10 :         spin_lock(&sbi->inode_hash_lock);
     604          20 :         if (i_pos != MSDOS_I(inode)->i_pos) {
     605          10 :                 spin_unlock(&sbi->inode_hash_lock);
     606          10 :                 brelse(bh);
     607           5 :                 goto retry;
     608             :         }
     609             : 
     610           5 :         raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
     611             :             [i_pos & (sbi->dir_per_block - 1)];
     612          15 :         if (S_ISDIR(inode->i_mode))
     613           5 :                 raw_entry->size = 0;
     614             :         else
     615          10 :                 raw_entry->size = cpu_to_le32(inode->i_size);
     616          10 :         raw_entry->attr = fat_make_attrs(inode);
     617          20 :         raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
     618          15 :         raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
     619          10 :         fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
     620             :                           &raw_entry->date, NULL);
     621          10 :         if (sbi->options.isvfat) {
     622             :                 __le16 atime;
     623          10 :                 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
     624             :                                   &raw_entry->cdate, &raw_entry->ctime_cs);
     625          10 :                 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
     626             :                                   &raw_entry->adate, NULL);
     627             :         }
     628          20 :         spin_unlock(&sbi->inode_hash_lock);
     629           5 :         mark_buffer_dirty(bh);
     630           5 :         err = 0;
     631          10 :         if (wait)
     632           5 :                 err = sync_dirty_buffer(bh);
     633          10 :         brelse(bh);
     634           5 :         return err;
     635             : }
     636             : 
     637             : int fat_sync_inode(struct inode *inode)
     638             : {
     639          28 :         return fat_write_inode(inode, 1);
     640             : }
     641             : 
     642             : EXPORT_SYMBOL_GPL(fat_sync_inode);
     643             : 
     644             : static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
     645           1 : static const struct super_operations fat_sops = {
     646             :         .alloc_inode    = fat_alloc_inode,
     647             :         .destroy_inode  = fat_destroy_inode,
     648             :         .write_inode    = fat_write_inode,
     649             :         .delete_inode   = fat_delete_inode,
     650             :         .put_super      = fat_put_super,
     651             :         .write_super    = fat_write_super,
     652             :         .sync_fs        = fat_sync_fs,
     653             :         .statfs         = fat_statfs,
     654             :         .clear_inode    = fat_clear_inode,
     655             :         .remount_fs     = fat_remount,
     656             : 
     657             :         .show_options   = fat_show_options,
     658             : };
     659             : 
     660             : /*
     661             :  * a FAT file handle with fhtype 3 is
     662             :  *  0/  i_ino - for fast, reliable lookup if still in the cache
     663             :  *  1/  i_generation - to see if i_ino is still valid
     664             :  *          bit 0 == 0 iff directory
     665             :  *  2/  i_pos(8-39) - if ino has changed, but still in cache
     666             :  *  3/  i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
     667             :  *  4/  i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
     668             :  *
     669             :  * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
     670             :  * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
     671             :  * of i_logstart is used to store the directory entry offset.
     672             :  */
     673             : 
     674             : static struct dentry *fat_fh_to_dentry(struct super_block *sb,
     675             :                 struct fid *fid, int fh_len, int fh_type)
     676             : {
     677           2 :         struct inode *inode = NULL;
     678           1 :         struct dentry *result;
     679           2 :         u32 *fh = fid->raw;
     680           1 : 
     681           5 :         if (fh_len < 5 || fh_type != 3)
     682           2 :                 return NULL;
     683           1 : 
     684           1 :         inode = ilookup(sb, fh[0]);
     685           4 :         if (!inode || inode->i_generation != fh[1]) {
     686           2 :                 if (inode)
     687           1 :                         iput(inode);
     688           1 :                 inode = NULL;
     689             :         }
     690           2 :         if (!inode) {
     691             :                 loff_t i_pos;
     692           1 :                 int i_logstart = fh[3] & 0x0fffffff;
     693             : 
     694           1 :                 i_pos = (loff_t)fh[2] << 8;
     695           1 :                 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
     696             : 
     697             :                 /* try 2 - see if i_pos is in F-d-c
     698             :                  * require i_logstart to be the same
     699             :                  * Will fail if you truncate and then re-write
     700             :                  */
     701             : 
     702           2 :                 inode = fat_iget(sb, i_pos);
     703           6 :                 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
     704           1 :                         iput(inode);
     705           1 :                         inode = NULL;
     706             :                 }
     707             :         }
     708             : 
     709             :         /*
     710             :          * For now, do nothing if the inode is not found.
     711             :          *
     712             :          * What we could do is:
     713             :          *
     714             :          *      - follow the file starting at fh[4], and record the ".." entry,
     715             :          *        and the name of the fh[2] entry.
     716             :          *      - then follow the ".." file finding the next step up.
     717             :          *
     718             :          * This way we build a path to the root of the tree. If this works, we
     719             :          * lookup the path and so get this inode into the cache.  Finally try
     720             :          * the fat_iget lookup again.  If that fails, then we are totally out
     721             :          * of luck.  But all that is for another day
     722             :          */
     723           3 :         result = d_obtain_alias(inode);
     724           8 :         if (!IS_ERR(result))
     725           1 :                 result->d_op = sb->s_root->d_op;
     726           1 :         return result;
     727             : }
     728             : 
     729             : static int
     730             : fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
     731             : {
     732           2 :         int len = *lenp;
     733           2 :         struct inode *inode =  de->d_inode;
     734           1 :         u32 ipos_h, ipos_m, ipos_l;
     735           1 : 
     736           3 :         if (len < 5)
     737           2 :                 return 255; /* no room */
     738           1 : 
     739           4 :         ipos_h = MSDOS_I(inode)->i_pos >> 8;
     740           5 :         ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
     741           4 :         ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
     742           1 :         *lenp = 5;
     743           2 :         fh[0] = inode->i_ino;
     744           1 :         fh[1] = inode->i_generation;
     745           1 :         fh[2] = ipos_h;
     746           4 :         fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
     747           2 :         spin_lock(&de->d_lock);
     748           4 :         fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
     749           2 :         spin_unlock(&de->d_lock);
     750           1 :         return 3;
     751             : }
     752             : 
     753             : static struct dentry *fat_get_parent(struct dentry *child)
     754             : {
     755           2 :         struct super_block *sb = child->d_sb;
     756           1 :         struct buffer_head *bh;
     757           1 :         struct msdos_dir_entry *de;
     758           1 :         loff_t i_pos;
     759           1 :         struct dentry *parent;
     760           1 :         struct inode *inode;
     761           1 :         int err;
     762           1 : 
     763           2 :         lock_super(sb);
     764             : 
     765           3 :         err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
     766           2 :         if (err) {
     767           3 :                 parent = ERR_PTR(err);
     768           1 :                 goto out;
     769             :         }
     770           5 :         inode = fat_build_inode(sb, de, i_pos);
     771           2 :         brelse(bh);
     772             : 
     773           1 :         parent = d_obtain_alias(inode);
     774           4 :         if (!IS_ERR(parent))
     775           1 :                 parent->d_op = sb->s_root->d_op;
     776             : out:
     777           2 :         unlock_super(sb);
     778             : 
     779           3 :         return parent;
     780             : }
     781             : 
     782           1 : static const struct export_operations fat_export_ops = {
     783             :         .encode_fh      = fat_encode_fh,
     784             :         .fh_to_dentry   = fat_fh_to_dentry,
     785             :         .get_parent     = fat_get_parent,
     786             : };
     787             : 
     788             : static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
     789             : {
     790           4 :         struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
     791           2 :         struct fat_mount_options *opts = &sbi->options;
     792           3 :         int isvfat = opts->isvfat;
     793           1 : 
     794           2 :         if (opts->fs_uid != 0)
     795           1 :                 seq_printf(m, ",uid=%u", opts->fs_uid);
     796           2 :         if (opts->fs_gid != 0)
     797           1 :                 seq_printf(m, ",gid=%u", opts->fs_gid);
     798           2 :         seq_printf(m, ",fmask=%04o", opts->fs_fmask);
     799           2 :         seq_printf(m, ",dmask=%04o", opts->fs_dmask);
     800           3 :         if (opts->allow_utime)
     801           2 :                 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
     802           3 :         if (sbi->nls_disk)
     803           1 :                 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
     804           2 :         if (isvfat) {
     805           3 :                 if (sbi->nls_io)
     806           1 :                         seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
     807             : 
     808             :                 switch (opts->shortname) {
     809           4 :                 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
     810           1 :                         seq_puts(m, ",shortname=win95");
     811           1 :                         break;
     812           5 :                 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
     813           1 :                         seq_puts(m, ",shortname=winnt");
     814           1 :                         break;
     815           5 :                 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
     816           1 :                         seq_puts(m, ",shortname=mixed");
     817           1 :                         break;
     818           5 :                 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
     819           1 :                         seq_puts(m, ",shortname=lower");
     820           1 :                         break;
     821           2 :                 default:
     822           2 :                         seq_puts(m, ",shortname=unknown");
     823           1 :                         break;
     824             :                 }
     825             :         }
     826           3 :         if (opts->name_check != 'n')
     827           2 :                 seq_printf(m, ",check=%c", opts->name_check);
     828           2 :         if (opts->usefree)
     829           1 :                 seq_puts(m, ",usefree");
     830           2 :         if (opts->quiet)
     831           1 :                 seq_puts(m, ",quiet");
     832           2 :         if (opts->showexec)
     833           1 :                 seq_puts(m, ",showexec");
     834           2 :         if (opts->sys_immutable)
     835           1 :                 seq_puts(m, ",sys_immutable");
     836           2 :         if (!isvfat) {
     837           2 :                 if (opts->dotsOK)
     838           1 :                         seq_puts(m, ",dotsOK=yes");
     839           2 :                 if (opts->nocase)
     840           1 :                         seq_puts(m, ",nocase");
     841             :         } else {
     842           2 :                 if (opts->utf8)
     843           1 :                         seq_puts(m, ",utf8");
     844           2 :                 if (opts->unicode_xlate)
     845           1 :                         seq_puts(m, ",uni_xlate");
     846           2 :                 if (!opts->numtail)
     847           1 :                         seq_puts(m, ",nonumtail");
     848           2 :                 if (opts->rodir)
     849           1 :                         seq_puts(m, ",rodir");
     850             :         }
     851           2 :         if (opts->flush)
     852           1 :                 seq_puts(m, ",flush");
     853           2 :         if (opts->tz_utc)
     854           1 :                 seq_puts(m, ",tz=UTC");
     855           3 :         if (opts->errors == FAT_ERRORS_CONT)
     856           1 :                 seq_puts(m, ",errors=continue");
     857           3 :         else if (opts->errors == FAT_ERRORS_PANIC)
     858           1 :                 seq_puts(m, ",errors=panic");
     859             :         else
     860           1 :                 seq_puts(m, ",errors=remount-ro");
     861           2 :         if (opts->discard)
     862           1 :                 seq_puts(m, ",discard");
     863             : 
     864           1 :         return 0;
     865             : }
     866             : 
     867             : enum {
     868             :         Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
     869             :         Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
     870             :         Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
     871             :         Opt_immutable, Opt_dots, Opt_nodots,
     872             :         Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
     873             :         Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
     874             :         Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
     875             :         Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
     876             :         Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
     877             : };
     878             : 
     879           1 : static const match_table_t fat_tokens = {
     880             :         {Opt_check_r, "check=relaxed"},
     881             :         {Opt_check_s, "check=strict"},
     882             :         {Opt_check_n, "check=normal"},
     883             :         {Opt_check_r, "check=r"},
     884             :         {Opt_check_s, "check=s"},
     885             :         {Opt_check_n, "check=n"},
     886             :         {Opt_uid, "uid=%u"},
     887             :         {Opt_gid, "gid=%u"},
     888             :         {Opt_umask, "umask=%o"},
     889             :         {Opt_dmask, "dmask=%o"},
     890             :         {Opt_fmask, "fmask=%o"},
     891             :         {Opt_allow_utime, "allow_utime=%o"},
     892             :         {Opt_codepage, "codepage=%u"},
     893             :         {Opt_usefree, "usefree"},
     894             :         {Opt_nocase, "nocase"},
     895             :         {Opt_quiet, "quiet"},
     896             :         {Opt_showexec, "showexec"},
     897             :         {Opt_debug, "debug"},
     898             :         {Opt_immutable, "sys_immutable"},
     899             :         {Opt_flush, "flush"},
     900             :         {Opt_tz_utc, "tz=UTC"},
     901             :         {Opt_err_cont, "errors=continue"},
     902             :         {Opt_err_panic, "errors=panic"},
     903             :         {Opt_err_ro, "errors=remount-ro"},
     904             :         {Opt_discard, "discard"},
     905             :         {Opt_obsolate, "conv=binary"},
     906             :         {Opt_obsolate, "conv=text"},
     907             :         {Opt_obsolate, "conv=auto"},
     908             :         {Opt_obsolate, "conv=b"},
     909             :         {Opt_obsolate, "conv=t"},
     910             :         {Opt_obsolate, "conv=a"},
     911             :         {Opt_obsolate, "fat=%u"},
     912             :         {Opt_obsolate, "blocksize=%u"},
     913             :         {Opt_obsolate, "cvf_format=%20s"},
     914             :         {Opt_obsolate, "cvf_options=%100s"},
     915             :         {Opt_obsolate, "posix"},
     916             :         {Opt_err, NULL},
     917             : };
     918           1 : static const match_table_t msdos_tokens = {
     919             :         {Opt_nodots, "nodots"},
     920             :         {Opt_nodots, "dotsOK=no"},
     921             :         {Opt_dots, "dots"},
     922             :         {Opt_dots, "dotsOK=yes"},
     923             :         {Opt_err, NULL}
     924             : };
     925           1 : static const match_table_t vfat_tokens = {
     926             :         {Opt_charset, "iocharset=%s"},
     927             :         {Opt_shortname_lower, "shortname=lower"},
     928             :         {Opt_shortname_win95, "shortname=win95"},
     929             :         {Opt_shortname_winnt, "shortname=winnt"},
     930             :         {Opt_shortname_mixed, "shortname=mixed"},
     931             :         {Opt_utf8_no, "utf8=0"},              /* 0 or no or false */
     932             :         {Opt_utf8_no, "utf8=no"},
     933             :         {Opt_utf8_no, "utf8=false"},
     934             :         {Opt_utf8_yes, "utf8=1"},             /* empty or 1 or yes or true */
     935             :         {Opt_utf8_yes, "utf8=yes"},
     936             :         {Opt_utf8_yes, "utf8=true"},
     937             :         {Opt_utf8_yes, "utf8"},
     938             :         {Opt_uni_xl_no, "uni_xlate=0"},               /* 0 or no or false */
     939             :         {Opt_uni_xl_no, "uni_xlate=no"},
     940             :         {Opt_uni_xl_no, "uni_xlate=false"},
     941             :         {Opt_uni_xl_yes, "uni_xlate=1"},      /* empty or 1 or yes or true */
     942             :         {Opt_uni_xl_yes, "uni_xlate=yes"},
     943             :         {Opt_uni_xl_yes, "uni_xlate=true"},
     944             :         {Opt_uni_xl_yes, "uni_xlate"},
     945             :         {Opt_nonumtail_no, "nonumtail=0"},    /* 0 or no or false */
     946             :         {Opt_nonumtail_no, "nonumtail=no"},
     947             :         {Opt_nonumtail_no, "nonumtail=false"},
     948             :         {Opt_nonumtail_yes, "nonumtail=1"},   /* empty or 1 or yes or true */
     949             :         {Opt_nonumtail_yes, "nonumtail=yes"},
     950             :         {Opt_nonumtail_yes, "nonumtail=true"},
     951             :         {Opt_nonumtail_yes, "nonumtail"},
     952             :         {Opt_rodir, "rodir"},
     953             :         {Opt_err, NULL}
     954             : };
     955             : 
     956             : static int parse_options(char *options, int is_vfat, int silent, int *debug,
     957             :                          struct fat_mount_options *opts)
     958           0 : {
     959           0 :         char *p;
     960           0 :         substring_t args[MAX_OPT_ARGS];
     961           0 :         int option;
     962           0 :         char *iocharset;
     963           0 : 
     964           0 :         opts->isvfat = is_vfat;
     965           0 : 
     966           0 :         opts->fs_uid = current_uid();
     967           0 :         opts->fs_gid = current_gid();
     968           0 :         opts->fs_fmask = opts->fs_dmask = current_umask();
     969           0 :         opts->allow_utime = -1;
     970           0 :         opts->codepage = fat_default_codepage;
     971           0 :         opts->iocharset = fat_default_iocharset;
     972           0 :         if (is_vfat) {
     973           0 :                 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
     974           0 :                 opts->rodir = 0;
     975           0 :         } else {
     976           0 :                 opts->shortname = 0;
     977           0 :                 opts->rodir = 1;
     978           0 :         }
     979           0 :         opts->name_check = 'n';
     980           0 :         opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
     981           0 :         opts->utf8 = opts->unicode_xlate = 0;
     982           0 :         opts->numtail = 1;
     983           0 :         opts->usefree = opts->nocase = 0;
     984           0 :         opts->tz_utc = 0;
     985           0 :         opts->errors = FAT_ERRORS_RO;
     986           0 :         *debug = 0;
     987             : 
     988           0 :         if (!options)
     989           0 :                 goto out;
     990             : 
     991           0 :         while ((p = strsep(&options, ",")) != NULL) {
     992           0 :                 int token;
     993           0 :                 if (!*p)
     994           0 :                         continue;
     995             : 
     996           0 :                 token = match_token(p, fat_tokens, args);
     997           0 :                 if (token == Opt_err) {
     998           0 :                         if (is_vfat)
     999           0 :                                 token = match_token(p, vfat_tokens, args);
    1000             :                         else
    1001           0 :                                 token = match_token(p, msdos_tokens, args);
    1002             :                 }
    1003             :                 switch (token) {
    1004           0 :                 case Opt_check_s:
    1005           0 :                         opts->name_check = 's';
    1006           0 :                         break;
    1007           0 :                 case Opt_check_r:
    1008           0 :                         opts->name_check = 'r';
    1009           0 :                         break;
    1010           0 :                 case Opt_check_n:
    1011           0 :                         opts->name_check = 'n';
    1012           0 :                         break;
    1013           0 :                 case Opt_usefree:
    1014           0 :                         opts->usefree = 1;
    1015           0 :                         break;
    1016           0 :                 case Opt_nocase:
    1017           0 :                         if (!is_vfat)
    1018           0 :                                 opts->nocase = 1;
    1019             :                         else {
    1020             :                                 /* for backward compatibility */
    1021           0 :                                 opts->shortname = VFAT_SFN_DISPLAY_WIN95
    1022             :                                         | VFAT_SFN_CREATE_WIN95;
    1023             :                         }
    1024           0 :                         break;
    1025           0 :                 case Opt_quiet:
    1026           0 :                         opts->quiet = 1;
    1027           0 :                         break;
    1028           0 :                 case Opt_showexec:
    1029           0 :                         opts->showexec = 1;
    1030           0 :                         break;
    1031           0 :                 case Opt_debug:
    1032           0 :                         *debug = 1;
    1033           0 :                         break;
    1034           0 :                 case Opt_immutable:
    1035           0 :                         opts->sys_immutable = 1;
    1036           0 :                         break;
    1037           0 :                 case Opt_uid:
    1038           0 :                         if (match_int(&args[0], &option))
    1039           0 :                                 return 0;
    1040           0 :                         opts->fs_uid = option;
    1041           0 :                         break;
    1042           0 :                 case Opt_gid:
    1043           0 :                         if (match_int(&args[0], &option))
    1044           0 :                                 return 0;
    1045           0 :                         opts->fs_gid = option;
    1046           0 :                         break;
    1047           0 :                 case Opt_umask:
    1048           0 :                         if (match_octal(&args[0], &option))
    1049           0 :                                 return 0;
    1050           0 :                         opts->fs_fmask = opts->fs_dmask = option;
    1051           0 :                         break;
    1052           0 :                 case Opt_dmask:
    1053           0 :                         if (match_octal(&args[0], &option))
    1054           0 :                                 return 0;
    1055           0 :                         opts->fs_dmask = option;
    1056           0 :                         break;
    1057           0 :                 case Opt_fmask:
    1058           0 :                         if (match_octal(&args[0], &option))
    1059           0 :                                 return 0;
    1060           0 :                         opts->fs_fmask = option;
    1061           0 :                         break;
    1062           0 :                 case Opt_allow_utime:
    1063           0 :                         if (match_octal(&args[0], &option))
    1064           0 :                                 return 0;
    1065           0 :                         opts->allow_utime = option & (S_IWGRP | S_IWOTH);
    1066           0 :                         break;
    1067           0 :                 case Opt_codepage:
    1068           0 :                         if (match_int(&args[0], &option))
    1069           0 :                                 return 0;
    1070           0 :                         opts->codepage = option;
    1071           0 :                         break;
    1072           0 :                 case Opt_flush:
    1073           0 :                         opts->flush = 1;
    1074           0 :                         break;
    1075           0 :                 case Opt_tz_utc:
    1076           0 :                         opts->tz_utc = 1;
    1077           0 :                         break;
    1078           0 :                 case Opt_err_cont:
    1079           0 :                         opts->errors = FAT_ERRORS_CONT;
    1080           0 :                         break;
    1081           0 :                 case Opt_err_panic:
    1082           0 :                         opts->errors = FAT_ERRORS_PANIC;
    1083           0 :                         break;
    1084           0 :                 case Opt_err_ro:
    1085           0 :                         opts->errors = FAT_ERRORS_RO;
    1086           0 :                         break;
    1087           0 : 
    1088             :                 /* msdos specific */
    1089           0 :                 case Opt_dots:
    1090           0 :                         opts->dotsOK = 1;
    1091           0 :                         break;
    1092           0 :                 case Opt_nodots:
    1093           0 :                         opts->dotsOK = 0;
    1094           0 :                         break;
    1095           0 : 
    1096             :                 /* vfat specific */
    1097           0 :                 case Opt_charset:
    1098           0 :                         if (opts->iocharset != fat_default_iocharset)
    1099           0 :                                 kfree(opts->iocharset);
    1100           0 :                         iocharset = match_strdup(&args[0]);
    1101           0 :                         if (!iocharset)
    1102           0 :                                 return -ENOMEM;
    1103           0 :                         opts->iocharset = iocharset;
    1104           0 :                         break;
    1105           0 :                 case Opt_shortname_lower:
    1106           0 :                         opts->shortname = VFAT_SFN_DISPLAY_LOWER
    1107             :                                         | VFAT_SFN_CREATE_WIN95;
    1108           0 :                         break;
    1109           0 :                 case Opt_shortname_win95:
    1110           0 :                         opts->shortname = VFAT_SFN_DISPLAY_WIN95
    1111             :                                         | VFAT_SFN_CREATE_WIN95;
    1112           0 :                         break;
    1113           0 :                 case Opt_shortname_winnt:
    1114           0 :                         opts->shortname = VFAT_SFN_DISPLAY_WINNT
    1115             :                                         | VFAT_SFN_CREATE_WINNT;
    1116           0 :                         break;
    1117           0 :                 case Opt_shortname_mixed:
    1118           0 :                         opts->shortname = VFAT_SFN_DISPLAY_WINNT
    1119             :                                         | VFAT_SFN_CREATE_WIN95;
    1120           0 :                         break;
    1121           0 :                 case Opt_utf8_no:               /* 0 or no or false */
    1122           0 :                         opts->utf8 = 0;
    1123           0 :                         break;
    1124           0 :                 case Opt_utf8_yes:              /* empty or 1 or yes or true */
    1125           0 :                         opts->utf8 = 1;
    1126           0 :                         break;
    1127           0 :                 case Opt_uni_xl_no:             /* 0 or no or false */
    1128           0 :                         opts->unicode_xlate = 0;
    1129           0 :                         break;
    1130           0 :                 case Opt_uni_xl_yes:            /* empty or 1 or yes or true */
    1131           0 :                         opts->unicode_xlate = 1;
    1132           0 :                         break;
    1133           0 :                 case Opt_nonumtail_no:          /* 0 or no or false */
    1134           0 :                         opts->numtail = 1;   /* negated option */
    1135           0 :                         break;
    1136           0 :                 case Opt_nonumtail_yes:         /* empty or 1 or yes or true */
    1137           0 :                         opts->numtail = 0;   /* negated option */
    1138           0 :                         break;
    1139           0 :                 case Opt_rodir:
    1140           0 :                         opts->rodir = 1;
    1141           0 :                         break;
    1142           0 :                 case Opt_discard:
    1143           0 :                         opts->discard = 1;
    1144           0 :                         break;
    1145           0 : 
    1146             :                 /* obsolete mount options */
    1147           0 :                 case Opt_obsolate:
    1148           0 :                         printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
    1149             :                                "not supported now\n", p);
    1150           0 :                         break;
    1151           0 :                 /* unknown option */
    1152           0 :                 default:
    1153           0 :                         if (!silent) {
    1154           0 :                                 printk(KERN_ERR
    1155             :                                        "FAT: Unrecognized mount option \"%s\" "
    1156             :                                        "or missing value\n", p);
    1157             :                         }
    1158           0 :                         return -EINVAL;
    1159             :                 }
    1160             :         }
    1161             : 
    1162           0 : out:
    1163             :         /* UTF-8 doesn't provide FAT semantics */
    1164           0 :         if (!strcmp(opts->iocharset, "utf8")) {
    1165           0 :                 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
    1166             :                        " for FAT filesystems, filesystem will be "
    1167             :                        "case sensitive!\n");
    1168             :         }
    1169             : 
    1170             :         /* If user doesn't specify allow_utime, it's initialized from dmask. */
    1171           0 :         if (opts->allow_utime == (unsigned short)-1)
    1172           0 :                 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
    1173           0 :         if (opts->unicode_xlate)
    1174           0 :                 opts->utf8 = 0;
    1175             : 
    1176           0 :         return 0;
    1177             : }
    1178             : 
    1179             : static int fat_read_root(struct inode *inode)
    1180             : {
    1181           0 :         struct super_block *sb = inode->i_sb;
    1182           0 :         struct msdos_sb_info *sbi = MSDOS_SB(sb);
    1183           0 :         int error;
    1184           0 : 
    1185           0 :         MSDOS_I(inode)->i_pos = 0;
    1186           0 :         inode->i_uid = sbi->options.fs_uid;
    1187           0 :         inode->i_gid = sbi->options.fs_gid;
    1188           0 :         inode->i_version++;
    1189           0 :         inode->i_generation = 0;
    1190           0 :         inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
    1191           0 :         inode->i_op = sbi->dir_ops;
    1192           0 :         inode->i_fop = &fat_dir_operations;
    1193           0 :         if (sbi->fat_bits == 32) {
    1194           0 :                 MSDOS_I(inode)->i_start = sbi->root_cluster;
    1195           0 :                 error = fat_calc_dir_size(inode);
    1196           0 :                 if (error < 0)
    1197           0 :                         return error;
    1198             :         } else {
    1199           0 :                 MSDOS_I(inode)->i_start = 0;
    1200           0 :                 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
    1201             :         }
    1202           0 :         inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
    1203             :                            & ~((loff_t)sbi->cluster_size - 1)) >> 9;
    1204           0 :         MSDOS_I(inode)->i_logstart = 0;
    1205           0 :         MSDOS_I(inode)->mmu_private = inode->i_size;
    1206             : 
    1207           0 :         fat_save_attrs(inode, ATTR_DIR);
    1208           0 :         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
    1209           0 :         inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
    1210           0 :         inode->i_nlink = fat_subdirs(inode)+2;
    1211             : 
    1212           0 :         return 0;
    1213             : }
    1214             : 
    1215             : /*
    1216             :  * Read the super block of an MS-DOS FS.
    1217             :  */
    1218             : int fat_fill_super(struct super_block *sb, void *data, int silent,
    1219             :                    const struct inode_operations *fs_dir_inode_ops, int isvfat)
    1220             : {
    1221           0 :         struct inode *root_inode = NULL, *fat_inode = NULL;
    1222           0 :         struct buffer_head *bh;
    1223           0 :         struct fat_boot_sector *b;
    1224           0 :         struct msdos_sb_info *sbi;
    1225           0 :         u16 logical_sector_size;
    1226           0 :         u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
    1227           0 :         int debug;
    1228           0 :         unsigned int media;
    1229           0 :         long error;
    1230           0 :         char buf[50];
    1231           0 : 
    1232           0 :         /*
    1233           0 :          * GFP_KERNEL is ok here, because while we do hold the
    1234           0 :          * supeblock lock, memory pressure can't call back into
    1235           0 :          * the filesystem, since we're only just about to mount
    1236           0 :          * it and have no inodes etc active!
    1237           0 :          */
    1238           0 :         sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
    1239           0 :         if (!sbi)
    1240           0 :                 return -ENOMEM;
    1241           0 :         sb->s_fs_info = sbi;
    1242           0 : 
    1243           0 :         sb->s_flags |= MS_NODIRATIME;
    1244           0 :         sb->s_magic = MSDOS_SUPER_MAGIC;
    1245           0 :         sb->s_op = &fat_sops;
    1246           0 :         sb->s_export_op = &fat_export_ops;
    1247           0 :         sbi->dir_ops = fs_dir_inode_ops;
    1248           0 : 
    1249           0 :         error = parse_options(data, isvfat, silent, &debug, &sbi->options);
    1250           0 :         if (error)
    1251           0 :                 goto out_fail;
    1252           0 : 
    1253           0 :         error = -EIO;
    1254           0 :         sb_min_blocksize(sb, 512);
    1255           0 :         bh = sb_bread(sb, 0);
    1256           0 :         if (bh == NULL) {
    1257           0 :                 printk(KERN_ERR "FAT: unable to read boot sector\n");
    1258           0 :                 goto out_fail;
    1259             :         }
    1260             : 
    1261           0 :         b = (struct fat_boot_sector *) bh->b_data;
    1262           0 :         if (!b->reserved) {
    1263           0 :                 if (!silent)
    1264           0 :                         printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
    1265           0 :                 brelse(bh);
    1266           0 :                 goto out_invalid;
    1267             :         }
    1268           0 :         if (!b->fats) {
    1269           0 :                 if (!silent)
    1270           0 :                         printk(KERN_ERR "FAT: bogus number of FAT structure\n");
    1271           0 :                 brelse(bh);
    1272           0 :                 goto out_invalid;
    1273             :         }
    1274             : 
    1275             :         /*
    1276             :          * Earlier we checked here that b->secs_track and b->head are nonzero,
    1277             :          * but it turns out valid FAT filesystems can have zero there.
    1278             :          */
    1279             : 
    1280           0 :         media = b->media;
    1281           0 :         if (!fat_valid_media(media)) {
    1282           0 :                 if (!silent)
    1283           0 :                         printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
    1284             :                                media);
    1285           0 :                 brelse(bh);
    1286           0 :                 goto out_invalid;
    1287             :         }
    1288           0 :         logical_sector_size = get_unaligned_le16(&b->sector_size);
    1289           0 :         if (!is_power_of_2(logical_sector_size)
    1290             :             || (logical_sector_size < 512)
    1291             :             || (logical_sector_size > 4096)) {
    1292           0 :                 if (!silent)
    1293           0 :                         printk(KERN_ERR "FAT: bogus logical sector size %u\n",
    1294             :                                logical_sector_size);
    1295           0 :                 brelse(bh);
    1296           0 :                 goto out_invalid;
    1297             :         }
    1298           0 :         sbi->sec_per_clus = b->sec_per_clus;
    1299           0 :         if (!is_power_of_2(sbi->sec_per_clus)) {
    1300           0 :                 if (!silent)
    1301           0 :                         printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
    1302             :                                sbi->sec_per_clus);
    1303           0 :                 brelse(bh);
    1304           0 :                 goto out_invalid;
    1305             :         }
    1306             : 
    1307           0 :         if (logical_sector_size < sb->s_blocksize) {
    1308           0 :                 printk(KERN_ERR "FAT: logical sector size too small for device"
    1309             :                        " (logical sector size = %u)\n", logical_sector_size);
    1310           0 :                 brelse(bh);
    1311           0 :                 goto out_fail;
    1312             :         }
    1313           0 :         if (logical_sector_size > sb->s_blocksize) {
    1314           0 :                 brelse(bh);
    1315             : 
    1316           0 :                 if (!sb_set_blocksize(sb, logical_sector_size)) {
    1317           0 :                         printk(KERN_ERR "FAT: unable to set blocksize %u\n",
    1318             :                                logical_sector_size);
    1319           0 :                         goto out_fail;
    1320             :                 }
    1321           0 :                 bh = sb_bread(sb, 0);
    1322           0 :                 if (bh == NULL) {
    1323           0 :                         printk(KERN_ERR "FAT: unable to read boot sector"
    1324             :                                " (logical sector size = %lu)\n",
    1325             :                                sb->s_blocksize);
    1326           0 :                         goto out_fail;
    1327             :                 }
    1328           0 :                 b = (struct fat_boot_sector *) bh->b_data;
    1329             :         }
    1330             : 
    1331           0 :         sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
    1332           0 :         sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
    1333           0 :         sbi->fats = b->fats;
    1334           0 :         sbi->fat_bits = 0;           /* Don't know yet */
    1335           0 :         sbi->fat_start = le16_to_cpu(b->reserved);
    1336           0 :         sbi->fat_length = le16_to_cpu(b->fat_length);
    1337           0 :         sbi->root_cluster = 0;
    1338           0 :         sbi->free_clusters = -1;     /* Don't know yet */
    1339           0 :         sbi->free_clus_valid = 0;
    1340           0 :         sbi->prev_free = FAT_START_ENT;
    1341             : 
    1342           0 :         if (!sbi->fat_length && b->fat32_length) {
    1343             :                 struct fat_boot_fsinfo *fsinfo;
    1344             :                 struct buffer_head *fsinfo_bh;
    1345             : 
    1346             :                 /* Must be FAT32 */
    1347           0 :                 sbi->fat_bits = 32;
    1348           0 :                 sbi->fat_length = le32_to_cpu(b->fat32_length);
    1349           0 :                 sbi->root_cluster = le32_to_cpu(b->root_cluster);
    1350             : 
    1351           0 :                 sb->s_maxbytes = 0xffffffff;
    1352             : 
    1353             :                 /* MC - if info_sector is 0, don't multiply by 0 */
    1354           0 :                 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
    1355           0 :                 if (sbi->fsinfo_sector == 0)
    1356           0 :                         sbi->fsinfo_sector = 1;
    1357             : 
    1358           0 :                 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
    1359           0 :                 if (fsinfo_bh == NULL) {
    1360           0 :                         printk(KERN_ERR "FAT: bread failed, FSINFO block"
    1361             :                                " (sector = %lu)\n", sbi->fsinfo_sector);
    1362           0 :                         brelse(bh);
    1363           0 :                         goto out_fail;
    1364             :                 }
    1365             : 
    1366           0 :                 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
    1367           0 :                 if (!IS_FSINFO(fsinfo)) {
    1368           0 :                         printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
    1369             :                                "0x%08x, 0x%08x (sector = %lu)\n",
    1370             :                                le32_to_cpu(fsinfo->signature1),
    1371             :                                le32_to_cpu(fsinfo->signature2),
    1372             :                                sbi->fsinfo_sector);
    1373             :                 } else {
    1374           0 :                         if (sbi->options.usefree)
    1375           0 :                                 sbi->free_clus_valid = 1;
    1376           0 :                         sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
    1377           0 :                         sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
    1378             :                 }
    1379             : 
    1380           0 :                 brelse(fsinfo_bh);
    1381             :         }
    1382             : 
    1383           0 :         sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
    1384           0 :         sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
    1385             : 
    1386           0 :         sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
    1387           0 :         sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
    1388           0 :         if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
    1389           0 :                 if (!silent)
    1390           0 :                         printk(KERN_ERR "FAT: bogus directroy-entries per block"
    1391             :                                " (%u)\n", sbi->dir_entries);
    1392           0 :                 brelse(bh);
    1393           0 :                 goto out_invalid;
    1394             :         }
    1395             : 
    1396           0 :         rootdir_sectors = sbi->dir_entries
    1397             :                 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
    1398           0 :         sbi->data_start = sbi->dir_start + rootdir_sectors;
    1399           0 :         total_sectors = get_unaligned_le16(&b->sectors);
    1400           0 :         if (total_sectors == 0)
    1401           0 :                 total_sectors = le32_to_cpu(b->total_sect);
    1402             : 
    1403           0 :         total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
    1404             : 
    1405           0 :         if (sbi->fat_bits != 32)
    1406           0 :                 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
    1407             : 
    1408             :         /* check that FAT table does not overflow */
    1409           0 :         fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
    1410           0 :         total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
    1411           0 :         if (total_clusters > MAX_FAT(sb)) {
    1412           0 :                 if (!silent)
    1413           0 :                         printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
    1414             :                                total_clusters);
    1415           0 :                 brelse(bh);
    1416           0 :                 goto out_invalid;
    1417             :         }
    1418             : 
    1419           0 :         sbi->max_cluster = total_clusters + FAT_START_ENT;
    1420             :         /* check the free_clusters, it's not necessarily correct */
    1421           0 :         if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
    1422           0 :                 sbi->free_clusters = -1;
    1423             :         /* check the prev_free, it's not necessarily correct */
    1424           0 :         sbi->prev_free %= sbi->max_cluster;
    1425           0 :         if (sbi->prev_free < FAT_START_ENT)
    1426           0 :                 sbi->prev_free = FAT_START_ENT;
    1427             : 
    1428           0 :         brelse(bh);
    1429             : 
    1430             :         /* set up enough so that it can read an inode */
    1431           0 :         fat_hash_init(sb);
    1432           0 :         fat_ent_access_init(sb);
    1433             : 
    1434             :         /*
    1435             :          * The low byte of FAT's first entry must have same value with
    1436             :          * media-field.  But in real world, too many devices is
    1437             :          * writing wrong value.  So, removed that validity check.
    1438             :          *
    1439             :          * if (FAT_FIRST_ENT(sb, media) != first)
    1440             :          */
    1441             : 
    1442           0 :         error = -EINVAL;
    1443           0 :         sprintf(buf, "cp%d", sbi->options.codepage);
    1444           0 :         sbi->nls_disk = load_nls(buf);
    1445           0 :         if (!sbi->nls_disk) {
    1446           0 :                 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
    1447           0 :                 goto out_fail;
    1448             :         }
    1449             : 
    1450             :         /* FIXME: utf8 is using iocharset for upper/lower conversion */
    1451           0 :         if (sbi->options.isvfat) {
    1452           0 :                 sbi->nls_io = load_nls(sbi->options.iocharset);
    1453           0 :                 if (!sbi->nls_io) {
    1454           0 :                         printk(KERN_ERR "FAT: IO charset %s not found\n",
    1455             :                                sbi->options.iocharset);
    1456           0 :                         goto out_fail;
    1457             :                 }
    1458             :         }
    1459             : 
    1460           0 :         error = -ENOMEM;
    1461           0 :         fat_inode = new_inode(sb);
    1462           0 :         if (!fat_inode)
    1463           0 :                 goto out_fail;
    1464           0 :         MSDOS_I(fat_inode)->i_pos = 0;
    1465           0 :         sbi->fat_inode = fat_inode;
    1466           0 :         root_inode = new_inode(sb);
    1467           0 :         if (!root_inode)
    1468           0 :                 goto out_fail;
    1469           0 :         root_inode->i_ino = MSDOS_ROOT_INO;
    1470           0 :         root_inode->i_version = 1;
    1471           0 :         error = fat_read_root(root_inode);
    1472           0 :         if (error < 0)
    1473           0 :                 goto out_fail;
    1474           0 :         error = -ENOMEM;
    1475           0 :         insert_inode_hash(root_inode);
    1476           0 :         sb->s_root = d_alloc_root(root_inode);
    1477           0 :         if (!sb->s_root) {
    1478           0 :                 printk(KERN_ERR "FAT: get root inode failed\n");
    1479           0 :                 goto out_fail;
    1480             :         }
    1481             : 
    1482           0 :         return 0;
    1483           0 : 
    1484             : out_invalid:
    1485           0 :         error = -EINVAL;
    1486           0 :         if (!silent)
    1487           0 :                 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
    1488             :                        " on dev %s.\n", sb->s_id);
    1489             : 
    1490             : out_fail:
    1491           0 :         if (fat_inode)
    1492           0 :                 iput(fat_inode);
    1493           0 :         if (root_inode)
    1494           0 :                 iput(root_inode);
    1495           0 :         if (sbi->nls_io)
    1496           0 :                 unload_nls(sbi->nls_io);
    1497           0 :         if (sbi->nls_disk)
    1498           0 :                 unload_nls(sbi->nls_disk);
    1499           0 :         if (sbi->options.iocharset != fat_default_iocharset)
    1500           0 :                 kfree(sbi->options.iocharset);
    1501           0 :         sb->s_fs_info = NULL;
    1502           0 :         kfree(sbi);
    1503           0 :         return error;
    1504             : }
    1505             : 
    1506             : EXPORT_SYMBOL_GPL(fat_fill_super);
    1507             : 
    1508             : /*
    1509             :  * helper function for fat_flush_inodes.  This writes both the inode
    1510             :  * and the file data blocks, waiting for in flight data blocks before
    1511             :  * the start of the call.  It does not wait for any io started
    1512             :  * during the call
    1513             :  */
    1514             : static int writeback_inode(struct inode *inode)
    1515             : {
    1516           9 : 
    1517           9 :         int ret;
    1518          18 :         struct address_space *mapping = inode->i_mapping;
    1519         144 :         struct writeback_control wbc = {
    1520             :                .sync_mode = WB_SYNC_NONE,
    1521             :               .nr_to_write = 0,
    1522             :         };
    1523             :         /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
    1524             :         * inode to finish.  So WB_SYNC_NONE is sent down to sync_inode
    1525             :         * and filemap_fdatawrite is used for the data blocks
    1526             :         */
    1527           9 :         ret = sync_inode(inode, &wbc);
    1528          18 :         if (!ret)
    1529           9 :                ret = filemap_fdatawrite(mapping);
    1530           9 :         return ret;
    1531             : }
    1532             : 
    1533             : /*
    1534             :  * write data and metadata corresponding to i1 and i2.  The io is
    1535             :  * started but we do not wait for any of it to finish.
    1536             :  *
    1537             :  * filemap_flush is used for the block device, so if there is a dirty
    1538             :  * page for a block already in flight, we will not wait and start the
    1539             :  * io over again
    1540             :  */
    1541             : int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
    1542             : {
    1543           6 :         int ret = 0;
    1544          15 :         if (!MSDOS_SB(sb)->options.flush)
    1545           6 :                 return 0;
    1546           6 :         if (i1)
    1547           6 :                 ret = writeback_inode(i1);
    1548          24 :         if (!ret && i2)
    1549          12 :                 ret = writeback_inode(i2);
    1550          18 :         if (!ret) {
    1551           9 :                 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
    1552           9 :                 ret = filemap_flush(mapping);
    1553             :         }
    1554           9 :         return ret;
    1555             : }
    1556             : EXPORT_SYMBOL_GPL(fat_flush_inodes);
    1557             : 
    1558             : static int __init init_fat_fs(void)
    1559             : {
    1560           1 :         int err;
    1561             : 
    1562           2 :         err = fat_cache_init();
    1563           2 :         if (err)
    1564           1 :                 return err;
    1565             : 
    1566           2 :         err = fat_init_inodecache();
    1567           2 :         if (err)
    1568           1 :                 goto failed;
    1569             : 
    1570           1 :         return 0;
    1571           1 : 
    1572             : failed:
    1573           2 :         fat_cache_destroy();
    1574           1 :         return err;
    1575             : }
    1576             : 
    1577             : static void __exit exit_fat_fs(void)
    1578             : {
    1579           4 :         fat_cache_destroy();
    1580           4 :         fat_destroy_inodecache();
    1581           2 : }
    1582             : 
    1583             : module_init(init_fat_fs)
    1584             : module_exit(exit_fat_fs)
    1585           1 : 
    1586             : MODULE_LICENSE("GPL");

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