1 files changed, 1351 insertions, 0 deletions

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
new file mode 100644
index 000000000000..8ccee8415488
--- /dev/null
+++ b/fs/fat/inode.c
@@ -0,0 +1,1351 @@
+/*
+ *  linux/fs/fat/inode.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *  VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
+ *  Rewritten for the constant inumbers support by Al Viro
+ *
+ *  Fixes:
+ *
+ *      Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/seq_file.h>
+#include <linux/msdos_fs.h>
+#include <linux/pagemap.h>
+#include <linux/buffer_head.h>
+#include <linux/mount.h>
+#include <linux/vfs.h>
+#include <linux/parser.h>
+#include <asm/unaligned.h>
+
+#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
+/* if user don't select VFAT, this is undefined. */
+#define CONFIG_FAT_DEFAULT_IOCHARSET    ""
+#endif
+
+static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
+static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
+
+
+static int fat_add_cluster(struct inode *inode)
+{
+        int err, cluster;
+
+        err = fat_alloc_clusters(inode, &cluster, 1);
+        if (err)
+                return err;
+        /* FIXME: this cluster should be added after data of this
+         * cluster is writed */
+        err = fat_chain_add(inode, cluster, 1);
+        if (err)
+                fat_free_clusters(inode, cluster);
+        return err;
+}
+
+static int fat_get_block(struct inode *inode, sector_t iblock,
+                         struct buffer_head *bh_result, int create)
+{
+        struct super_block *sb = inode->i_sb;
+        sector_t phys;
+        int err;
+
+        err = fat_bmap(inode, iblock, &phys);
+        if (err)
+                return err;
+        if (phys) {
+                map_bh(bh_result, sb, phys);
+                return 0;
+        }
+        if (!create)
+                return 0;
+        if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
+                fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
+                             MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
+                return -EIO;
+        }
+        if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) {
+                err = fat_add_cluster(inode);
+                if (err)
+                        return err;
+        }
+        MSDOS_I(inode)->mmu_private += sb->s_blocksize;
+        err = fat_bmap(inode, iblock, &phys);
+        if (err)
+                return err;
+        if (!phys)
+                BUG();
+        set_buffer_new(bh_result);
+        map_bh(bh_result, sb, phys);
+        return 0;
+}
+
+static int fat_writepage(struct page *page, struct writeback_control *wbc)
+{
+        return block_write_full_page(page, fat_get_block, wbc);
+}
+
+static int fat_readpage(struct file *file, struct page *page)
+{
+        return block_read_full_page(page, fat_get_block);
+}
+
+static int fat_prepare_write(struct file *file, struct page *page,
+                             unsigned from, unsigned to)
+{
+        return cont_prepare_write(page, from, to, fat_get_block,
+                                  &MSDOS_I(page->mapping->host)->mmu_private);
+}
+
+static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
+{
+        return generic_block_bmap(mapping, block, fat_get_block);
+}
+
+static struct address_space_operations fat_aops = {
+        .readpage       = fat_readpage,
+        .writepage      = fat_writepage,
+        .sync_page      = block_sync_page,
+        .prepare_write  = fat_prepare_write,
+        .commit_write   = generic_commit_write,
+        .bmap           = _fat_bmap
+};
+
+/*
+ * New FAT inode stuff. We do the following:
+ *      a) i_ino is constant and has nothing with on-disk location.
+ *      b) FAT manages its own cache of directory entries.
+ *      c) *This* cache is indexed by on-disk location.
+ *      d) inode has an associated directory entry, all right, but
+ *              it may be unhashed.
+ *      e) currently entries are stored within struct inode. That should
+ *              change.
+ *      f) we deal with races in the following way:
+ *              1. readdir() and lookup() do FAT-dir-cache lookup.
+ *              2. rename() unhashes the F-d-c entry and rehashes it in
+ *                      a new place.
+ *              3. unlink() and rmdir() unhash F-d-c entry.
+ *              4. fat_write_inode() checks whether the thing is unhashed.
+ *                      If it is we silently return. If it isn't we do bread(),
+ *                      check if the location is still valid and retry if it
+ *                      isn't. Otherwise we do changes.
+ *              5. Spinlock is used to protect hash/unhash/location check/lookup
+ *              6. fat_clear_inode() unhashes the F-d-c entry.
+ *              7. lookup() and readdir() do igrab() if they find a F-d-c entry
+ *                      and consider negative result as cache miss.
+ */
+
+static void fat_hash_init(struct super_block *sb)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        int i;
+
+        spin_lock_init(&sbi->inode_hash_lock);
+        for (i = 0; i < FAT_HASH_SIZE; i++)
+                INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
+}
+
+static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
+{
+        unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
+        tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
+        return tmp & FAT_HASH_MASK;
+}
+
+void fat_attach(struct inode *inode, loff_t i_pos)
+{
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+        spin_lock(&sbi->inode_hash_lock);
+        MSDOS_I(inode)->i_pos = i_pos;
+        hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
+                        sbi->inode_hashtable + fat_hash(sb, i_pos));
+        spin_unlock(&sbi->inode_hash_lock);
+}
+
+EXPORT_SYMBOL(fat_attach);
+
+void fat_detach(struct inode *inode)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+        spin_lock(&sbi->inode_hash_lock);
+        MSDOS_I(inode)->i_pos = 0;
+        hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
+        spin_unlock(&sbi->inode_hash_lock);
+}
+
+EXPORT_SYMBOL(fat_detach);
+
+struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
+        struct hlist_node *_p;
+        struct msdos_inode_info *i;
+        struct inode *inode = NULL;
+
+        spin_lock(&sbi->inode_hash_lock);
+        hlist_for_each_entry(i, _p, head, i_fat_hash) {
+                BUG_ON(i->vfs_inode.i_sb != sb);
+                if (i->i_pos != i_pos)
+                        continue;
+                inode = igrab(&i->vfs_inode);
+                if (inode)
+                        break;
+        }
+        spin_unlock(&sbi->inode_hash_lock);
+        return inode;
+}
+
+static int is_exec(unsigned char *extension)
+{
+        unsigned char *exe_extensions = "EXECOMBAT", *walk;
+
+        for (walk = exe_extensions; *walk; walk += 3)
+                if (!strncmp(extension, walk, 3))
+                        return 1;
+        return 0;
+}
+
+static int fat_calc_dir_size(struct inode *inode)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+        int ret, fclus, dclus;
+
+        inode->i_size = 0;
+        if (MSDOS_I(inode)->i_start == 0)
+                return 0;
+
+        ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
+        if (ret < 0)
+                return ret;
+        inode->i_size = (fclus + 1) << sbi->cluster_bits;
+
+        return 0;
+}
+
+/* doesn't deal with root inode */
+static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+        int error;
+
+        MSDOS_I(inode)->i_pos = 0;
+        inode->i_uid = sbi->options.fs_uid;
+        inode->i_gid = sbi->options.fs_gid;
+        inode->i_version++;
+        inode->i_generation = get_seconds();
+
+        if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
+                inode->i_generation &= ~1;
+                inode->i_mode = MSDOS_MKMODE(de->attr,
+                        S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
+                inode->i_op = sbi->dir_ops;
+                inode->i_fop = &fat_dir_operations;
+
+                MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
+                if (sbi->fat_bits == 32)
+                        MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
+
+                MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
+                error = fat_calc_dir_size(inode);
+                if (error < 0)
+                        return error;
+                MSDOS_I(inode)->mmu_private = inode->i_size;
+
+                inode->i_nlink = fat_subdirs(inode);
+        } else { /* not a directory */
+                inode->i_generation |= 1;
+                inode->i_mode = MSDOS_MKMODE(de->attr,
+                    ((sbi->options.showexec &&
+                        !is_exec(de->ext))
+                        ? S_IRUGO|S_IWUGO : S_IRWXUGO)
+                    & ~sbi->options.fs_fmask) | S_IFREG;
+                MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
+                if (sbi->fat_bits == 32)
+                        MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
+
+                MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
+                inode->i_size = le32_to_cpu(de->size);
+                inode->i_op = &fat_file_inode_operations;
+                inode->i_fop = &fat_file_operations;
+                inode->i_mapping->a_ops = &fat_aops;
+                MSDOS_I(inode)->mmu_private = inode->i_size;
+        }
+        if (de->attr & ATTR_SYS) {
+                if (sbi->options.sys_immutable)
+                        inode->i_flags |= S_IMMUTABLE;
+        }
+        MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
+        /* this is as close to the truth as we can get ... */
+        inode->i_blksize = sbi->cluster_size;
+        inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
+                           & ~((loff_t)sbi->cluster_size - 1)) >> 9;
+        inode->i_mtime.tv_sec = inode->i_atime.tv_sec =
+                date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
+        inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0;
+        if (sbi->options.isvfat) {
+                int secs = de->ctime_cs / 100;
+                int csecs = de->ctime_cs % 100;
+                inode->i_ctime.tv_sec  =
+                        date_dos2unix(le16_to_cpu(de->ctime),
+                                      le16_to_cpu(de->cdate)) + secs;
+                inode->i_ctime.tv_nsec = csecs * 10000000;
+        } else
+                inode->i_ctime = inode->i_mtime;
+
+        return 0;
+}
+
+struct inode *fat_build_inode(struct super_block *sb,
+                        struct msdos_dir_entry *de, loff_t i_pos)
+{
+        struct inode *inode;
+        int err;
+
+        inode = fat_iget(sb, i_pos);
+        if (inode)
+                goto out;
+        inode = new_inode(sb);
+        if (!inode) {
+                inode = ERR_PTR(-ENOMEM);
+                goto out;
+        }
+        inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
+        inode->i_version = 1;
+        err = fat_fill_inode(inode, de);
+        if (err) {
+                iput(inode);
+                inode = ERR_PTR(err);
+                goto out;
+        }
+        fat_attach(inode, i_pos);
+        insert_inode_hash(inode);
+out:
+        return inode;
+}
+
+EXPORT_SYMBOL(fat_build_inode);
+
+static void fat_delete_inode(struct inode *inode)
+{
+        if (!is_bad_inode(inode)) {
+                inode->i_size = 0;
+                fat_truncate(inode);
+        }
+        clear_inode(inode);
+}
+
+static void fat_clear_inode(struct inode *inode)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+
+        if (is_bad_inode(inode))
+                return;
+        lock_kernel();
+        spin_lock(&sbi->inode_hash_lock);
+        fat_cache_inval_inode(inode);
+        hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
+        spin_unlock(&sbi->inode_hash_lock);
+        unlock_kernel();
+}
+
+static void fat_put_super(struct super_block *sb)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+        if (!(sb->s_flags & MS_RDONLY))
+                fat_clusters_flush(sb);
+
+        if (sbi->nls_disk) {
+                unload_nls(sbi->nls_disk);
+                sbi->nls_disk = NULL;
+                sbi->options.codepage = fat_default_codepage;
+        }
+        if (sbi->nls_io) {
+                unload_nls(sbi->nls_io);
+                sbi->nls_io = NULL;
+        }
+        if (sbi->options.iocharset != fat_default_iocharset) {
+                kfree(sbi->options.iocharset);
+                sbi->options.iocharset = fat_default_iocharset;
+        }
+
+        sb->s_fs_info = NULL;
+        kfree(sbi);
+}
+
+static kmem_cache_t *fat_inode_cachep;
+
+static struct inode *fat_alloc_inode(struct super_block *sb)
+{
+        struct msdos_inode_info *ei;
+        ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
+        if (!ei)
+                return NULL;
+        return &ei->vfs_inode;
+}
+
+static void fat_destroy_inode(struct inode *inode)
+{
+        kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
+}
+
+static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
+{
+        struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
+
+        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+            SLAB_CTOR_CONSTRUCTOR) {
+                spin_lock_init(&ei->cache_lru_lock);
+                ei->nr_caches = 0;
+                ei->cache_valid_id = FAT_CACHE_VALID + 1;
+                INIT_LIST_HEAD(&ei->cache_lru);
+                INIT_HLIST_NODE(&ei->i_fat_hash);
+                inode_init_once(&ei->vfs_inode);
+        }
+}
+
+static int __init fat_init_inodecache(void)
+{
+        fat_inode_cachep = kmem_cache_create("fat_inode_cache",
+                                             sizeof(struct msdos_inode_info),
+                                             0, SLAB_RECLAIM_ACCOUNT,
+                                             init_once, NULL);
+        if (fat_inode_cachep == NULL)
+                return -ENOMEM;
+        return 0;
+}
+
+static void __exit fat_destroy_inodecache(void)
+{
+        if (kmem_cache_destroy(fat_inode_cachep))
+                printk(KERN_INFO "fat_inode_cache: not all structures were freed\n");
+}
+
+static int fat_remount(struct super_block *sb, int *flags, char *data)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
+        return 0;
+}
+
+static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+        /* If the count of free cluster is still unknown, counts it here. */
+        if (sbi->free_clusters == -1) {
+                int err = fat_count_free_clusters(sb);
+                if (err)
+                        return err;
+        }
+
+        buf->f_type = sb->s_magic;
+        buf->f_bsize = sbi->cluster_size;
+        buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
+        buf->f_bfree = sbi->free_clusters;
+        buf->f_bavail = sbi->free_clusters;
+        buf->f_namelen = sbi->options.isvfat ? 260 : 12;
+
+        return 0;
+}
+
+static int fat_write_inode(struct inode *inode, int wait)
+{
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        struct buffer_head *bh;
+        struct msdos_dir_entry *raw_entry;
+        loff_t i_pos;
+        int err = 0;
+
+retry:
+        i_pos = MSDOS_I(inode)->i_pos;
+        if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
+                return 0;
+
+        lock_kernel();
+        bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
+        if (!bh) {
+                printk(KERN_ERR "FAT: unable to read inode block "
+                       "for updating (i_pos %lld)\n", i_pos);
+                err = -EIO;
+                goto out;
+        }
+        spin_lock(&sbi->inode_hash_lock);
+        if (i_pos != MSDOS_I(inode)->i_pos) {
+                spin_unlock(&sbi->inode_hash_lock);
+                brelse(bh);
+                unlock_kernel();
+                goto retry;
+        }
+
+        raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
+            [i_pos & (sbi->dir_per_block - 1)];
+        if (S_ISDIR(inode->i_mode))
+                raw_entry->size = 0;
+        else
+                raw_entry->size = cpu_to_le32(inode->i_size);
+        raw_entry->attr = fat_attr(inode);
+        raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
+        raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
+        fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
+        if (sbi->options.isvfat) {
+                fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
+                raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
+                        inode->i_ctime.tv_nsec / 10000000;
+        }
+        spin_unlock(&sbi->inode_hash_lock);
+        mark_buffer_dirty(bh);
+        if (wait)
+                err = sync_dirty_buffer(bh);
+        brelse(bh);
+out:
+        unlock_kernel();
+        return err;
+}
+
+int fat_sync_inode(struct inode *inode)
+{
+        return fat_write_inode(inode, 1);
+}
+
+EXPORT_SYMBOL(fat_sync_inode);
+
+static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
+static struct super_operations fat_sops = {
+        .alloc_inode    = fat_alloc_inode,
+        .destroy_inode  = fat_destroy_inode,
+        .write_inode    = fat_write_inode,
+        .delete_inode   = fat_delete_inode,
+        .put_super      = fat_put_super,
+        .statfs         = fat_statfs,
+        .clear_inode    = fat_clear_inode,
+        .remount_fs     = fat_remount,
+
+        .read_inode     = make_bad_inode,
+
+        .show_options   = fat_show_options,
+};
+
+/*
+ * a FAT file handle with fhtype 3 is
+ *  0/  i_ino - for fast, reliable lookup if still in the cache
+ *  1/  i_generation - to see if i_ino is still valid
+ *          bit 0 == 0 iff directory
+ *  2/  i_pos(8-39) - if ino has changed, but still in cache
+ *  3/  i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
+ *  4/  i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
+ *
+ * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
+ * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
+ * of i_logstart is used to store the directory entry offset.
+ */
+
+static struct dentry *
+fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
+              int (*acceptable)(void *context, struct dentry *de),
+              void *context)
+{
+        if (fhtype != 3)
+                return ERR_PTR(-ESTALE);
+        if (len < 5)
+                return ERR_PTR(-ESTALE);
+
+        return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
+}
+
+static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
+{
+        struct inode *inode = NULL;
+        struct dentry *result;
+        __u32 *fh = inump;
+
+        inode = iget(sb, fh[0]);
+        if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
+                if (inode)
+                        iput(inode);
+                inode = NULL;
+        }
+        if (!inode) {
+                loff_t i_pos;
+                int i_logstart = fh[3] & 0x0fffffff;
+
+                i_pos = (loff_t)fh[2] << 8;
+                i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
+
+                /* try 2 - see if i_pos is in F-d-c
+                 * require i_logstart to be the same
+                 * Will fail if you truncate and then re-write
+                 */
+
+                inode = fat_iget(sb, i_pos);
+                if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
+                        iput(inode);
+                        inode = NULL;
+                }
+        }
+        if (!inode) {
+                /* For now, do nothing
+                 * What we could do is:
+                 * follow the file starting at fh[4], and record
+                 * the ".." entry, and the name of the fh[2] entry.
+                 * The follow the ".." file finding the next step up.
+                 * This way we build a path to the root of
+                 * the tree. If this works, we lookup the path and so
+                 * get this inode into the cache.
+                 * Finally try the fat_iget lookup again
+                 * If that fails, then weare totally out of luck
+                 * But all that is for another day
+                 */
+        }
+        if (!inode)
+                return ERR_PTR(-ESTALE);
+
+
+        /* now to find a dentry.
+         * If possible, get a well-connected one
+         */
+        result = d_alloc_anon(inode);
+        if (result == NULL) {
+                iput(inode);
+                return ERR_PTR(-ENOMEM);
+        }
+        result->d_op = sb->s_root->d_op;
+        return result;
+}
+
+static int
+fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
+{
+        int len = *lenp;
+        struct inode *inode =  de->d_inode;
+        u32 ipos_h, ipos_m, ipos_l;
+
+        if (len < 5)
+                return 255; /* no room */
+
+        ipos_h = MSDOS_I(inode)->i_pos >> 8;
+        ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
+        ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
+        *lenp = 5;
+        fh[0] = inode->i_ino;
+        fh[1] = inode->i_generation;
+        fh[2] = ipos_h;
+        fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
+        spin_lock(&de->d_lock);
+        fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
+        spin_unlock(&de->d_lock);
+        return 3;
+}
+
+static struct dentry *fat_get_parent(struct dentry *child)
+{
+        struct buffer_head *bh;
+        struct msdos_dir_entry *de;
+        loff_t i_pos;
+        struct dentry *parent;
+        struct inode *inode;
+        int err;
+
+        lock_kernel();
+
+        err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
+        if (err) {
+                parent = ERR_PTR(err);
+                goto out;
+        }
+        inode = fat_build_inode(child->d_sb, de, i_pos);
+        brelse(bh);
+        if (IS_ERR(inode)) {
+                parent = ERR_PTR(PTR_ERR(inode));
+                goto out;
+        }
+        parent = d_alloc_anon(inode);
+        if (!parent) {
+                iput(inode);
+                parent = ERR_PTR(-ENOMEM);
+        }
+out:
+        unlock_kernel();
+
+        return parent;
+}
+
+static struct export_operations fat_export_ops = {
+        .decode_fh      = fat_decode_fh,
+        .encode_fh      = fat_encode_fh,
+        .get_dentry     = fat_get_dentry,
+        .get_parent     = fat_get_parent,
+};
+
+static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
+{
+        struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
+        struct fat_mount_options *opts = &sbi->options;
+        int isvfat = opts->isvfat;
+
+        if (opts->fs_uid != 0)
+                seq_printf(m, ",uid=%u", opts->fs_uid);
+        if (opts->fs_gid != 0)
+                seq_printf(m, ",gid=%u", opts->fs_gid);
+        seq_printf(m, ",fmask=%04o", opts->fs_fmask);
+        seq_printf(m, ",dmask=%04o", opts->fs_dmask);
+        if (sbi->nls_disk)
+                seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
+        if (isvfat) {
+                if (sbi->nls_io)
+                        seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
+
+                switch (opts->shortname) {
+                case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
+                        seq_puts(m, ",shortname=win95");
+                        break;
+                case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
+                        seq_puts(m, ",shortname=winnt");
+                        break;
+                case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
+                        seq_puts(m, ",shortname=mixed");
+                        break;
+                case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
+                        /* seq_puts(m, ",shortname=lower"); */
+                        break;
+                default:
+                        seq_puts(m, ",shortname=unknown");
+                        break;
+                }
+        }
+        if (opts->name_check != 'n')
+                seq_printf(m, ",check=%c", opts->name_check);
+        if (opts->quiet)
+                seq_puts(m, ",quiet");
+        if (opts->showexec)
+                seq_puts(m, ",showexec");
+        if (opts->sys_immutable)
+                seq_puts(m, ",sys_immutable");
+        if (!isvfat) {
+                if (opts->dotsOK)
+                        seq_puts(m, ",dotsOK=yes");
+                if (opts->nocase)
+                        seq_puts(m, ",nocase");
+        } else {
+                if (opts->utf8)
+                        seq_puts(m, ",utf8");
+                if (opts->unicode_xlate)
+                        seq_puts(m, ",uni_xlate");
+                if (!opts->numtail)
+                        seq_puts(m, ",nonumtail");
+        }
+
+        return 0;
+}
+
+enum {
+        Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
+        Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
+        Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
+        Opt_dots, Opt_nodots,
+        Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
+        Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
+        Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
+        Opt_obsolate, Opt_err,
+};
+
+static match_table_t fat_tokens = {
+        {Opt_check_r, "check=relaxed"},
+        {Opt_check_s, "check=strict"},
+        {Opt_check_n, "check=normal"},
+        {Opt_check_r, "check=r"},
+        {Opt_check_s, "check=s"},
+        {Opt_check_n, "check=n"},
+        {Opt_uid, "uid=%u"},
+        {Opt_gid, "gid=%u"},
+        {Opt_umask, "umask=%o"},
+        {Opt_dmask, "dmask=%o"},
+        {Opt_fmask, "fmask=%o"},
+        {Opt_codepage, "codepage=%u"},
+        {Opt_nocase, "nocase"},
+        {Opt_quiet, "quiet"},
+        {Opt_showexec, "showexec"},
+        {Opt_debug, "debug"},
+        {Opt_immutable, "sys_immutable"},
+        {Opt_obsolate, "conv=binary"},
+        {Opt_obsolate, "conv=text"},
+        {Opt_obsolate, "conv=auto"},
+        {Opt_obsolate, "conv=b"},
+        {Opt_obsolate, "conv=t"},
+        {Opt_obsolate, "conv=a"},
+        {Opt_obsolate, "fat=%u"},
+        {Opt_obsolate, "blocksize=%u"},
+        {Opt_obsolate, "cvf_format=%20s"},
+        {Opt_obsolate, "cvf_options=%100s"},
+        {Opt_obsolate, "posix"},
+        {Opt_err, NULL}
+};
+static match_table_t msdos_tokens = {
+        {Opt_nodots, "nodots"},
+        {Opt_nodots, "dotsOK=no"},
+        {Opt_dots, "dots"},
+        {Opt_dots, "dotsOK=yes"},
+        {Opt_err, NULL}
+};
+static match_table_t vfat_tokens = {
+        {Opt_charset, "iocharset=%s"},
+        {Opt_shortname_lower, "shortname=lower"},
+        {Opt_shortname_win95, "shortname=win95"},
+        {Opt_shortname_winnt, "shortname=winnt"},
+        {Opt_shortname_mixed, "shortname=mixed"},
+        {Opt_utf8_no, "utf8=0"},                /* 0 or no or false */
+        {Opt_utf8_no, "utf8=no"},
+        {Opt_utf8_no, "utf8=false"},
+        {Opt_utf8_yes, "utf8=1"},               /* empty or 1 or yes or true */
+        {Opt_utf8_yes, "utf8=yes"},
+        {Opt_utf8_yes, "utf8=true"},
+        {Opt_utf8_yes, "utf8"},
+        {Opt_uni_xl_no, "uni_xlate=0"},         /* 0 or no or false */
+        {Opt_uni_xl_no, "uni_xlate=no"},
+        {Opt_uni_xl_no, "uni_xlate=false"},
+        {Opt_uni_xl_yes, "uni_xlate=1"},        /* empty or 1 or yes or true */
+        {Opt_uni_xl_yes, "uni_xlate=yes"},
+        {Opt_uni_xl_yes, "uni_xlate=true"},
+        {Opt_uni_xl_yes, "uni_xlate"},
+        {Opt_nonumtail_no, "nonumtail=0"},      /* 0 or no or false */
+        {Opt_nonumtail_no, "nonumtail=no"},
+        {Opt_nonumtail_no, "nonumtail=false"},
+        {Opt_nonumtail_yes, "nonumtail=1"},     /* empty or 1 or yes or true */
+        {Opt_nonumtail_yes, "nonumtail=yes"},
+        {Opt_nonumtail_yes, "nonumtail=true"},
+        {Opt_nonumtail_yes, "nonumtail"},
+        {Opt_err, NULL}
+};
+
+static int parse_options(char *options, int is_vfat, int *debug,
+                         struct fat_mount_options *opts)
+{
+        char *p;
+        substring_t args[MAX_OPT_ARGS];
+        int option;
+        char *iocharset;
+
+        opts->isvfat = is_vfat;
+
+        opts->fs_uid = current->uid;
+        opts->fs_gid = current->gid;
+        opts->fs_fmask = opts->fs_dmask = current->fs->umask;
+        opts->codepage = fat_default_codepage;
+        opts->iocharset = fat_default_iocharset;
+        if (is_vfat)
+                opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
+        else
+                opts->shortname = 0;
+        opts->name_check = 'n';
+        opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;
+        opts->utf8 = opts->unicode_xlate = 0;
+        opts->numtail = 1;
+        opts->nocase = 0;
+        *debug = 0;
+
+        if (!options)
+                return 0;
+
+        while ((p = strsep(&options, ",")) != NULL) {
+                int token;
+                if (!*p)
+                        continue;
+
+                token = match_token(p, fat_tokens, args);
+                if (token == Opt_err) {
+                        if (is_vfat)
+                                token = match_token(p, vfat_tokens, args);
+                        else
+                                token = match_token(p, msdos_tokens, args);
+                }
+                switch (token) {
+                case Opt_check_s:
+                        opts->name_check = 's';
+                        break;
+                case Opt_check_r:
+                        opts->name_check = 'r';
+                        break;
+                case Opt_check_n:
+                        opts->name_check = 'n';
+                        break;
+                case Opt_nocase:
+                        if (!is_vfat)
+                                opts->nocase = 1;
+                        else {
+                                /* for backward compatibility */
+                                opts->shortname = VFAT_SFN_DISPLAY_WIN95
+                                        | VFAT_SFN_CREATE_WIN95;
+                        }
+                        break;
+                case Opt_quiet:
+                        opts->quiet = 1;
+                        break;
+                case Opt_showexec:
+                        opts->showexec = 1;
+                        break;
+                case Opt_debug:
+                        *debug = 1;
+                        break;
+                case Opt_immutable:
+                        opts->sys_immutable = 1;
+                        break;
+                case Opt_uid:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        opts->fs_uid = option;
+                        break;
+                case Opt_gid:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        opts->fs_gid = option;
+                        break;
+                case Opt_umask:
+                        if (match_octal(&args[0], &option))
+                                return 0;
+                        opts->fs_fmask = opts->fs_dmask = option;
+                        break;
+                case Opt_dmask:
+                        if (match_octal(&args[0], &option))
+                                return 0;
+                        opts->fs_dmask = option;
+                        break;
+                case Opt_fmask:
+                        if (match_octal(&args[0], &option))
+                                return 0;
+                        opts->fs_fmask = option;
+                        break;
+                case Opt_codepage:
+                        if (match_int(&args[0], &option))
+                                return 0;
+                        opts->codepage = option;
+                        break;
+
+                /* msdos specific */
+                case Opt_dots:
+                        opts->dotsOK = 1;
+                        break;
+                case Opt_nodots:
+                        opts->dotsOK = 0;
+                        break;
+
+                /* vfat specific */
+                case Opt_charset:
+                        if (opts->iocharset != fat_default_iocharset)
+                                kfree(opts->iocharset);
+                        iocharset = match_strdup(&args[0]);
+                        if (!iocharset)
+                                return -ENOMEM;
+                        opts->iocharset = iocharset;
+                        break;
+                case Opt_shortname_lower:
+                        opts->shortname = VFAT_SFN_DISPLAY_LOWER
+                                        | VFAT_SFN_CREATE_WIN95;
+                        break;
+                case Opt_shortname_win95:
+                        opts->shortname = VFAT_SFN_DISPLAY_WIN95
+                                        | VFAT_SFN_CREATE_WIN95;
+                        break;
+                case Opt_shortname_winnt:
+                        opts->shortname = VFAT_SFN_DISPLAY_WINNT
+                                        | VFAT_SFN_CREATE_WINNT;
+                        break;
+                case Opt_shortname_mixed:
+                        opts->shortname = VFAT_SFN_DISPLAY_WINNT
+                                        | VFAT_SFN_CREATE_WIN95;
+                        break;
+                case Opt_utf8_no:               /* 0 or no or false */
+                        opts->utf8 = 0;
+                        break;
+                case Opt_utf8_yes:              /* empty or 1 or yes or true */
+                        opts->utf8 = 1;
+                        break;
+                case Opt_uni_xl_no:             /* 0 or no or false */
+                        opts->unicode_xlate = 0;
+                        break;
+                case Opt_uni_xl_yes:            /* empty or 1 or yes or true */
+                        opts->unicode_xlate = 1;
+                        break;
+                case Opt_nonumtail_no:          /* 0 or no or false */
+                        opts->numtail = 1;      /* negated option */
+                        break;
+                case Opt_nonumtail_yes:         /* empty or 1 or yes or true */
+                        opts->numtail = 0;      /* negated option */
+                        break;
+
+                /* obsolete mount options */
+                case Opt_obsolate:
+                        printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
+                               "not supported now\n", p);
+                        break;
+                /* unknown option */
+                default:
+                        printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" "
+                               "or missing value\n", p);
+                        return -EINVAL;
+                }
+        }
+        /* UTF8 doesn't provide FAT semantics */
+        if (!strcmp(opts->iocharset, "utf8")) {
+                printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
+                       " for FAT filesystems, filesystem will be case sensitive!\n");
+        }
+
+        if (opts->unicode_xlate)
+                opts->utf8 = 0;
+
+        return 0;
+}
+
+static int fat_read_root(struct inode *inode)
+{
+        struct super_block *sb = inode->i_sb;
+        struct msdos_sb_info *sbi = MSDOS_SB(sb);
+        int error;
+
+        MSDOS_I(inode)->i_pos = 0;
+        inode->i_uid = sbi->options.fs_uid;
+        inode->i_gid = sbi->options.fs_gid;
+        inode->i_version++;
+        inode->i_generation = 0;
+        inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
+        inode->i_op = sbi->dir_ops;
+        inode->i_fop = &fat_dir_operations;
+        if (sbi->fat_bits == 32) {
+                MSDOS_I(inode)->i_start = sbi->root_cluster;
+                error = fat_calc_dir_size(inode);
+                if (error < 0)
+                        return error;
+        } else {
+                MSDOS_I(inode)->i_start = 0;
+                inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
+        }
+        inode->i_blksize = sbi->cluster_size;
+        inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
+                           & ~((loff_t)sbi->cluster_size - 1)) >> 9;
+        MSDOS_I(inode)->i_logstart = 0;
+        MSDOS_I(inode)->mmu_private = inode->i_size;
+
+        MSDOS_I(inode)->i_attrs = ATTR_NONE;
+        inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
+        inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
+        inode->i_nlink = fat_subdirs(inode)+2;
+
+        return 0;
+}
+
+/*
+ * Read the super block of an MS-DOS FS.
+ */
+int fat_fill_super(struct super_block *sb, void *data, int silent,
+                   struct inode_operations *fs_dir_inode_ops, int isvfat)
+{
+        struct inode *root_inode = NULL;
+        struct buffer_head *bh;
+        struct fat_boot_sector *b;
+        struct msdos_sb_info *sbi;
+        u16 logical_sector_size;
+        u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
+        int debug;
+        unsigned int media;
+        long error;
+        char buf[50];
+
+        sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
+        if (!sbi)
+                return -ENOMEM;
+        sb->s_fs_info = sbi;
+        memset(sbi, 0, sizeof(struct msdos_sb_info));
+
+        sb->s_flags |= MS_NODIRATIME;
+        sb->s_magic = MSDOS_SUPER_MAGIC;
+        sb->s_op = &fat_sops;
+        sb->s_export_op = &fat_export_ops;
+        sbi->dir_ops = fs_dir_inode_ops;
+
+        error = parse_options(data, isvfat, &debug, &sbi->options);
+        if (error)
+                goto out_fail;
+
+        error = -EIO;
+        sb_min_blocksize(sb, 512);
+        bh = sb_bread(sb, 0);
+        if (bh == NULL) {
+                printk(KERN_ERR "FAT: unable to read boot sector\n");
+                goto out_fail;
+        }
+
+        b = (struct fat_boot_sector *) bh->b_data;
+        if (!b->reserved) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
+                brelse(bh);
+                goto out_invalid;
+        }
+        if (!b->fats) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: bogus number of FAT structure\n");
+                brelse(bh);
+                goto out_invalid;
+        }
+
+        /*
+         * Earlier we checked here that b->secs_track and b->head are nonzero,
+         * but it turns out valid FAT filesystems can have zero there.
+         */
+
+        media = b->media;
+        if (!FAT_VALID_MEDIA(media)) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
+                               media);
+                brelse(bh);
+                goto out_invalid;
+        }
+        logical_sector_size =
+                le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
+        if (!logical_sector_size
+            || (logical_sector_size & (logical_sector_size - 1))
+            || (logical_sector_size < 512)
+            || (PAGE_CACHE_SIZE < logical_sector_size)) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: bogus logical sector size %u\n",
+                               logical_sector_size);
+                brelse(bh);
+                goto out_invalid;
+        }
+        sbi->sec_per_clus = b->sec_per_clus;
+        if (!sbi->sec_per_clus
+            || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
+                               sbi->sec_per_clus);
+                brelse(bh);
+                goto out_invalid;
+        }
+
+        if (logical_sector_size < sb->s_blocksize) {
+                printk(KERN_ERR "FAT: logical sector size too small for device"
+                       " (logical sector size = %u)\n", logical_sector_size);
+                brelse(bh);
+                goto out_fail;
+        }
+        if (logical_sector_size > sb->s_blocksize) {
+                brelse(bh);
+
+                if (!sb_set_blocksize(sb, logical_sector_size)) {
+                        printk(KERN_ERR "FAT: unable to set blocksize %u\n",
+                               logical_sector_size);
+                        goto out_fail;
+                }
+                bh = sb_bread(sb, 0);
+                if (bh == NULL) {
+                        printk(KERN_ERR "FAT: unable to read boot sector"
+                               " (logical sector size = %lu)\n",
+                               sb->s_blocksize);
+                        goto out_fail;
+                }
+                b = (struct fat_boot_sector *) bh->b_data;
+        }
+
+        sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
+        sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
+        sbi->fats = b->fats;
+        sbi->fat_bits = 0;              /* Don't know yet */
+        sbi->fat_start = le16_to_cpu(b->reserved);
+        sbi->fat_length = le16_to_cpu(b->fat_length);
+        sbi->root_cluster = 0;
+        sbi->free_clusters = -1;        /* Don't know yet */
+        sbi->prev_free = FAT_START_ENT;
+
+        if (!sbi->fat_length && b->fat32_length) {
+                struct fat_boot_fsinfo *fsinfo;
+                struct buffer_head *fsinfo_bh;
+
+                /* Must be FAT32 */
+                sbi->fat_bits = 32;
+                sbi->fat_length = le32_to_cpu(b->fat32_length);
+                sbi->root_cluster = le32_to_cpu(b->root_cluster);
+
+                sb->s_maxbytes = 0xffffffff;
+
+                /* MC - if info_sector is 0, don't multiply by 0 */
+                sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
+                if (sbi->fsinfo_sector == 0)
+                        sbi->fsinfo_sector = 1;
+
+                fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
+                if (fsinfo_bh == NULL) {
+                        printk(KERN_ERR "FAT: bread failed, FSINFO block"
+                               " (sector = %lu)\n", sbi->fsinfo_sector);
+                        brelse(bh);
+                        goto out_fail;
+                }
+
+                fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
+                if (!IS_FSINFO(fsinfo)) {
+                        printk(KERN_WARNING
+                               "FAT: Did not find valid FSINFO signature.\n"
+                               "     Found signature1 0x%08x signature2 0x%08x"
+                               " (sector = %lu)\n",
+                               le32_to_cpu(fsinfo->signature1),
+                               le32_to_cpu(fsinfo->signature2),
+                               sbi->fsinfo_sector);
+                } else {
+                        sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
+                        sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
+                }
+
+                brelse(fsinfo_bh);
+        }
+
+        sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
+        sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
+
+        sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
+        sbi->dir_entries =
+                le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
+        if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: bogus directroy-entries per block"
+                               " (%u)\n", sbi->dir_entries);
+                brelse(bh);
+                goto out_invalid;
+        }
+
+        rootdir_sectors = sbi->dir_entries
+                * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
+        sbi->data_start = sbi->dir_start + rootdir_sectors;
+        total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
+        if (total_sectors == 0)
+                total_sectors = le32_to_cpu(b->total_sect);
+
+        total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
+
+        if (sbi->fat_bits != 32)
+                sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
+
+        /* check that FAT table does not overflow */
+        fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
+        total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
+        if (total_clusters > MAX_FAT(sb)) {
+                if (!silent)
+                        printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
+                               total_clusters);
+                brelse(bh);
+                goto out_invalid;
+        }
+
+        sbi->max_cluster = total_clusters + FAT_START_ENT;
+        /* check the free_clusters, it's not necessarily correct */
+        if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
+                sbi->free_clusters = -1;
+        /* check the prev_free, it's not necessarily correct */
+        sbi->prev_free %= sbi->max_cluster;
+        if (sbi->prev_free < FAT_START_ENT)
+                sbi->prev_free = FAT_START_ENT;
+
+        brelse(bh);
+
+        /* set up enough so that it can read an inode */
+        fat_hash_init(sb);
+        fat_ent_access_init(sb);
+
+        /*
+         * The low byte of FAT's first entry must have same value with
+         * media-field.  But in real world, too many devices is
+         * writing wrong value.  So, removed that validity check.
+         *
+         * if (FAT_FIRST_ENT(sb, media) != first)
+         */
+
+        error = -EINVAL;
+        sprintf(buf, "cp%d", sbi->options.codepage);
+        sbi->nls_disk = load_nls(buf);
+        if (!sbi->nls_disk) {
+                printk(KERN_ERR "FAT: codepage %s not found\n", buf);
+                goto out_fail;
+        }
+
+        /* FIXME: utf8 is using iocharset for upper/lower conversion */
+        if (sbi->options.isvfat) {
+                sbi->nls_io = load_nls(sbi->options.iocharset);
+                if (!sbi->nls_io) {
+                        printk(KERN_ERR "FAT: IO charset %s not found\n",
+                               sbi->options.iocharset);
+                        goto out_fail;
+                }
+        }
+
+        error = -ENOMEM;
+        root_inode = new_inode(sb);
+        if (!root_inode)
+                goto out_fail;
+        root_inode->i_ino = MSDOS_ROOT_INO;
+        root_inode->i_version = 1;
+        error = fat_read_root(root_inode);
+        if (error < 0)
+                goto out_fail;
+        error = -ENOMEM;
+        insert_inode_hash(root_inode);
+        sb->s_root = d_alloc_root(root_inode);
+        if (!sb->s_root) {
+                printk(KERN_ERR "FAT: get root inode failed\n");
+                goto out_fail;
+        }
+
+        return 0;
+
+out_invalid:
+        error = -EINVAL;
+        if (!silent)
+                printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
+                       " on dev %s.\n", sb->s_id);
+
+out_fail:
+        if (root_inode)
+                iput(root_inode);
+        if (sbi->nls_io)
+                unload_nls(sbi->nls_io);
+        if (sbi->nls_disk)
+                unload_nls(sbi->nls_disk);
+        if (sbi->options.iocharset != fat_default_iocharset)
+                kfree(sbi->options.iocharset);
+        sb->s_fs_info = NULL;
+        kfree(sbi);
+        return error;
+}
+
+EXPORT_SYMBOL(fat_fill_super);
+
+int __init fat_cache_init(void);
+void __exit fat_cache_destroy(void);
+
+static int __init init_fat_fs(void)
+{
+        int ret;
+
+        ret = fat_cache_init();
+        if (ret < 0)
+                return ret;
+        return fat_init_inodecache();
+}
+
+static void __exit exit_fat_fs(void)
+{
+        fat_cache_destroy();
+        fat_destroy_inodecache();
+}
+
+module_init(init_fat_fs)
+module_exit(exit_fat_fs)
+
+MODULE_LICENSE("GPL");