fat: move fs/vfat/* and fs/msdos/* to fs/fat

This just moves those files, but change link order from MSDOS, VFAT to
VFAT, MSDOS.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 1762 insertions, 1 deletions

diff --git a/fs/fat/Makefile b/fs/fat/Makefile
index bfb5f06..e061903 100644
--- a/fs/fat/Makefile
+++ b/fs/fat/Makefile
@@ -3,5 +3,9 @@
 #
 
 obj-$(CONFIG_FAT_FS) += fat.o
+obj-$(CONFIG_VFAT_FS) += vfat.o
+obj-$(CONFIG_MSDOS_FS) += msdos.o
 
-fat-objs := cache.o dir.o fatent.o file.o inode.o misc.o
+fat-y := cache.o dir.o fatent.o file.o inode.o misc.o
+vfat-y := namei_vfat.o
+msdos-y := namei_msdos.o
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
new file mode 100644
index 0000000..e844b98
--- /dev/null
+++ b/fs/fat/namei_msdos.c
@@ -0,0 +1,702 @@
+/*
+ *  linux/fs/msdos/namei.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
+ *  Rewritten for constant inumbers 1999 by Al Viro
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/buffer_head.h>
+#include <linux/msdos_fs.h>
+#include <linux/smp_lock.h>
+
+/* Characters that are undesirable in an MS-DOS file name */
+static unsigned char bad_chars[] = "*?<>|\"";
+static unsigned char bad_if_strict[] = "+=,; ";
+
+/***** Formats an MS-DOS file name. Rejects invalid names. */
+static int msdos_format_name(const unsigned char *name, int len,
+			     unsigned char *res, struct fat_mount_options *opts)
+	/*
+	 * name is the proposed name, len is its length, res is
+	 * the resulting name, opts->name_check is either (r)elaxed,
+	 * (n)ormal or (s)trict, opts->dotsOK allows dots at the
+	 * beginning of name (for hidden files)
+	 */
+{
+	unsigned char *walk;
+	unsigned char c;
+	int space;
+
+	if (name[0] == '.') {	/* dotfile because . and .. already done */
+		if (opts->dotsOK) {
+			/* Get rid of dot - test for it elsewhere */
+			name++;
+			len--;
+		} else
+			return -EINVAL;
+	}
+	/*
+	 * disallow names that _really_ start with a dot
+	 */
+	space = 1;
+	c = 0;
+	for (walk = res; len && walk - res < 8; walk++) {
+		c = *name++;
+		len--;
+		if (opts->name_check != 'r' && strchr(bad_chars, c))
+			return -EINVAL;
+		if (opts->name_check == 's' && strchr(bad_if_strict, c))
+			return -EINVAL;
+		if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
+			return -EINVAL;
+		if (c < ' ' || c == ':' || c == '\\')
+			return -EINVAL;
+	/*
+	 * 0xE5 is legal as a first character, but we must substitute
+	 * 0x05 because 0xE5 marks deleted files.  Yes, DOS really
+	 * does this.
+	 * It seems that Microsoft hacked DOS to support non-US
+	 * characters after the 0xE5 character was already in use to
+	 * mark deleted files.
+	 */
+		if ((res == walk) && (c == 0xE5))
+			c = 0x05;
+		if (c == '.')
+			break;
+		space = (c == ' ');
+		*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
+	}
+	if (space)
+		return -EINVAL;
+	if (opts->name_check == 's' && len && c != '.') {
+		c = *name++;
+		len--;
+		if (c != '.')
+			return -EINVAL;
+	}
+	while (c != '.' && len--)
+		c = *name++;
+	if (c == '.') {
+		while (walk - res < 8)
+			*walk++ = ' ';
+		while (len > 0 && walk - res < MSDOS_NAME) {
+			c = *name++;
+			len--;
+			if (opts->name_check != 'r' && strchr(bad_chars, c))
+				return -EINVAL;
+			if (opts->name_check == 's' &&
+			    strchr(bad_if_strict, c))
+				return -EINVAL;
+			if (c < ' ' || c == ':' || c == '\\')
+				return -EINVAL;
+			if (c == '.') {
+				if (opts->name_check == 's')
+					return -EINVAL;
+				break;
+			}
+			if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
+				return -EINVAL;
+			space = c == ' ';
+			if (!opts->nocase && c >= 'a' && c <= 'z')
+				*walk++ = c - 32;
+			else
+				*walk++ = c;
+		}
+		if (space)
+			return -EINVAL;
+		if (opts->name_check == 's' && len)
+			return -EINVAL;
+	}
+	while (walk - res < MSDOS_NAME)
+		*walk++ = ' ';
+
+	return 0;
+}
+
+/***** Locates a directory entry.  Uses unformatted name. */
+static int msdos_find(struct inode *dir, const unsigned char *name, int len,
+		      struct fat_slot_info *sinfo)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
+	unsigned char msdos_name[MSDOS_NAME];
+	int err;
+
+	err = msdos_format_name(name, len, msdos_name, &sbi->options);
+	if (err)
+		return -ENOENT;
+
+	err = fat_scan(dir, msdos_name, sinfo);
+	if (!err && sbi->options.dotsOK) {
+		if (name[0] == '.') {
+			if (!(sinfo->de->attr & ATTR_HIDDEN))
+				err = -ENOENT;
+		} else {
+			if (sinfo->de->attr & ATTR_HIDDEN)
+				err = -ENOENT;
+		}
+		if (err)
+			brelse(sinfo->bh);
+	}
+	return err;
+}
+
+/*
+ * Compute the hash for the msdos name corresponding to the dentry.
+ * Note: if the name is invalid, we leave the hash code unchanged so
+ * that the existing dentry can be used. The msdos fs routines will
+ * return ENOENT or EINVAL as appropriate.
+ */
+static int msdos_hash(struct dentry *dentry, struct qstr *qstr)
+{
+	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
+	unsigned char msdos_name[MSDOS_NAME];
+	int error;
+
+	error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
+	if (!error)
+		qstr->hash = full_name_hash(msdos_name, MSDOS_NAME);
+	return 0;
+}
+
+/*
+ * Compare two msdos names. If either of the names are invalid,
+ * we fall back to doing the standard name comparison.
+ */
+static int msdos_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+{
+	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
+	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
+	int error;
+
+	error = msdos_format_name(a->name, a->len, a_msdos_name, options);
+	if (error)
+		goto old_compare;
+	error = msdos_format_name(b->name, b->len, b_msdos_name, options);
+	if (error)
+		goto old_compare;
+	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
+out:
+	return error;
+
+old_compare:
+	error = 1;
+	if (a->len == b->len)
+		error = memcmp(a->name, b->name, a->len);
+	goto out;
+}
+
+static struct dentry_operations msdos_dentry_operations = {
+	.d_hash		= msdos_hash,
+	.d_compare	= msdos_cmp,
+};
+
+/*
+ * AV. Wrappers for FAT sb operations. Is it wise?
+ */
+
+/***** Get inode using directory and name */
+static struct dentry *msdos_lookup(struct inode *dir, struct dentry *dentry,
+				   struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	struct inode *inode = NULL;
+	int res;
+
+	dentry->d_op = &msdos_dentry_operations;
+
+	lock_super(sb);
+	res = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
+	if (res == -ENOENT)
+		goto add;
+	if (res < 0)
+		goto out;
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		res = PTR_ERR(inode);
+		goto out;
+	}
+add:
+	res = 0;
+	dentry = d_splice_alias(inode, dentry);
+	if (dentry)
+		dentry->d_op = &msdos_dentry_operations;
+out:
+	unlock_super(sb);
+	if (!res)
+		return dentry;
+	return ERR_PTR(res);
+}
+
+/***** Creates a directory entry (name is already formatted). */
+static int msdos_add_entry(struct inode *dir, const unsigned char *name,
+			   int is_dir, int is_hid, int cluster,
+			   struct timespec *ts, struct fat_slot_info *sinfo)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
+	struct msdos_dir_entry de;
+	__le16 time, date;
+	int err;
+
+	memcpy(de.name, name, MSDOS_NAME);
+	de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
+	if (is_hid)
+		de.attr |= ATTR_HIDDEN;
+	de.lcase = 0;
+	fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
+	de.cdate = de.adate = 0;
+	de.ctime = 0;
+	de.ctime_cs = 0;
+	de.time = time;
+	de.date = date;
+	de.start = cpu_to_le16(cluster);
+	de.starthi = cpu_to_le16(cluster >> 16);
+	de.size = 0;
+
+	err = fat_add_entries(dir, &de, 1, sinfo);
+	if (err)
+		return err;
+
+	dir->i_ctime = dir->i_mtime = *ts;
+	if (IS_DIRSYNC(dir))
+		(void)fat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+
+	return 0;
+}
+
+/***** Create a file */
+static int msdos_create(struct inode *dir, struct dentry *dentry, int mode,
+			struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = NULL;
+	struct fat_slot_info sinfo;
+	struct timespec ts;
+	unsigned char msdos_name[MSDOS_NAME];
+	int err, is_hid;
+
+	lock_super(sb);
+
+	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
+				msdos_name, &MSDOS_SB(sb)->options);
+	if (err)
+		goto out;
+	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
+	/* Have to do it due to foo vs. .foo conflicts */
+	if (!fat_scan(dir, msdos_name, &sinfo)) {
+		brelse(sinfo.bh);
+		err = -EINVAL;
+		goto out;
+	}
+
+	ts = CURRENT_TIME_SEC;
+	err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
+	if (err)
+		goto out;
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out;
+	}
+	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	d_instantiate(dentry, inode);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, dir, inode);
+	return err;
+}
+
+/***** Remove a directory */
+static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = dentry->d_inode;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_super(sb);
+	/*
+	 * Check whether the directory is not in use, then check
+	 * whether it is empty.
+	 */
+	err = fat_dir_empty(inode);
+	if (err)
+		goto out;
+	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
+	if (err)
+		goto out;
+
+	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
+	if (err)
+		goto out;
+	drop_nlink(dir);
+
+	clear_nlink(inode);
+	inode->i_ctime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, dir, inode);
+
+	return err;
+}
+
+/***** Make a directory */
+static int msdos_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	struct inode *inode;
+	unsigned char msdos_name[MSDOS_NAME];
+	struct timespec ts;
+	int err, is_hid, cluster;
+
+	lock_super(sb);
+
+	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
+				msdos_name, &MSDOS_SB(sb)->options);
+	if (err)
+		goto out;
+	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
+	/* foo vs .foo situation */
+	if (!fat_scan(dir, msdos_name, &sinfo)) {
+		brelse(sinfo.bh);
+		err = -EINVAL;
+		goto out;
+	}
+
+	ts = CURRENT_TIME_SEC;
+	cluster = fat_alloc_new_dir(dir, &ts);
+	if (cluster < 0) {
+		err = cluster;
+		goto out;
+	}
+	err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
+	if (err)
+		goto out_free;
+	inc_nlink(dir);
+
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		/* the directory was completed, just return a error */
+		goto out;
+	}
+	inode->i_nlink = 2;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	d_instantiate(dentry, inode);
+
+	unlock_super(sb);
+	fat_flush_inodes(sb, dir, inode);
+	return 0;
+
+out_free:
+	fat_free_clusters(dir, cluster);
+out:
+	unlock_super(sb);
+	return err;
+}
+
+/***** Unlink a file */
+static int msdos_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct super_block *sb= inode->i_sb;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_super(sb);
+	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
+	if (err)
+		goto out;
+
+	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
+	if (err)
+		goto out;
+	clear_nlink(inode);
+	inode->i_ctime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, dir, inode);
+
+	return err;
+}
+
+static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
+			   struct dentry *old_dentry,
+			   struct inode *new_dir, unsigned char *new_name,
+			   struct dentry *new_dentry, int is_hid)
+{
+	struct buffer_head *dotdot_bh;
+	struct msdos_dir_entry *dotdot_de;
+	struct inode *old_inode, *new_inode;
+	struct fat_slot_info old_sinfo, sinfo;
+	struct timespec ts;
+	loff_t dotdot_i_pos, new_i_pos;
+	int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
+
+	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
+	old_inode = old_dentry->d_inode;
+	new_inode = new_dentry->d_inode;
+
+	err = fat_scan(old_dir, old_name, &old_sinfo);
+	if (err) {
+		err = -EIO;
+		goto out;
+	}
+
+	is_dir = S_ISDIR(old_inode->i_mode);
+	update_dotdot = (is_dir && old_dir != new_dir);
+	if (update_dotdot) {
+		if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
+					 &dotdot_i_pos) < 0) {
+			err = -EIO;
+			goto out;
+		}
+	}
+
+	old_attrs = MSDOS_I(old_inode)->i_attrs;
+	err = fat_scan(new_dir, new_name, &sinfo);
+	if (!err) {
+		if (!new_inode) {
+			/* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
+			if (sinfo.de != old_sinfo.de) {
+				err = -EINVAL;
+				goto out;
+			}
+			if (is_hid)
+				MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
+			else
+				MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
+			if (IS_DIRSYNC(old_dir)) {
+				err = fat_sync_inode(old_inode);
+				if (err) {
+					MSDOS_I(old_inode)->i_attrs = old_attrs;
+					goto out;
+				}
+			} else
+				mark_inode_dirty(old_inode);
+
+			old_dir->i_version++;
+			old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
+			if (IS_DIRSYNC(old_dir))
+				(void)fat_sync_inode(old_dir);
+			else
+				mark_inode_dirty(old_dir);
+			goto out;
+		}
+	}
+
+	ts = CURRENT_TIME_SEC;
+	if (new_inode) {
+		if (err)
+			goto out;
+		if (is_dir) {
+			err = fat_dir_empty(new_inode);
+			if (err)
+				goto out;
+		}
+		new_i_pos = MSDOS_I(new_inode)->i_pos;
+		fat_detach(new_inode);
+	} else {
+		err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
+				      &ts, &sinfo);
+		if (err)
+			goto out;
+		new_i_pos = sinfo.i_pos;
+	}
+	new_dir->i_version++;
+
+	fat_detach(old_inode);
+	fat_attach(old_inode, new_i_pos);
+	if (is_hid)
+		MSDOS_I(old_inode)->i_attrs |= ATTR_HIDDEN;
+	else
+		MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
+	if (IS_DIRSYNC(new_dir)) {
+		err = fat_sync_inode(old_inode);
+		if (err)
+			goto error_inode;
+	} else
+		mark_inode_dirty(old_inode);
+
+	if (update_dotdot) {
+		int start = MSDOS_I(new_dir)->i_logstart;
+		dotdot_de->start = cpu_to_le16(start);
+		dotdot_de->starthi = cpu_to_le16(start >> 16);
+		mark_buffer_dirty(dotdot_bh);
+		if (IS_DIRSYNC(new_dir)) {
+			err = sync_dirty_buffer(dotdot_bh);
+			if (err)
+				goto error_dotdot;
+		}
+		drop_nlink(old_dir);
+		if (!new_inode)
+			inc_nlink(new_dir);
+	}
+
+	err = fat_remove_entries(old_dir, &old_sinfo);	/* and releases bh */
+	old_sinfo.bh = NULL;
+	if (err)
+		goto error_dotdot;
+	old_dir->i_version++;
+	old_dir->i_ctime = old_dir->i_mtime = ts;
+	if (IS_DIRSYNC(old_dir))
+		(void)fat_sync_inode(old_dir);
+	else
+		mark_inode_dirty(old_dir);
+
+	if (new_inode) {
+		drop_nlink(new_inode);
+		if (is_dir)
+			drop_nlink(new_inode);
+		new_inode->i_ctime = ts;
+	}
+out:
+	brelse(sinfo.bh);
+	brelse(dotdot_bh);
+	brelse(old_sinfo.bh);
+	return err;
+
+error_dotdot:
+	/* data cluster is shared, serious corruption */
+	corrupt = 1;
+
+	if (update_dotdot) {
+		int start = MSDOS_I(old_dir)->i_logstart;
+		dotdot_de->start = cpu_to_le16(start);
+		dotdot_de->starthi = cpu_to_le16(start >> 16);
+		mark_buffer_dirty(dotdot_bh);
+		corrupt |= sync_dirty_buffer(dotdot_bh);
+	}
+error_inode:
+	fat_detach(old_inode);
+	fat_attach(old_inode, old_sinfo.i_pos);
+	MSDOS_I(old_inode)->i_attrs = old_attrs;
+	if (new_inode) {
+		fat_attach(new_inode, new_i_pos);
+		if (corrupt)
+			corrupt |= fat_sync_inode(new_inode);
+	} else {
+		/*
+		 * If new entry was not sharing the data cluster, it
+		 * shouldn't be serious corruption.
+		 */
+		int err2 = fat_remove_entries(new_dir, &sinfo);
+		if (corrupt)
+			corrupt |= err2;
+		sinfo.bh = NULL;
+	}
+	if (corrupt < 0) {
+		fat_fs_panic(new_dir->i_sb,
+			     "%s: Filesystem corrupted (i_pos %lld)",
+			     __func__, sinfo.i_pos);
+	}
+	goto out;
+}
+
+/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
+static int msdos_rename(struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct super_block *sb = old_dir->i_sb;
+	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
+	int err, is_hid;
+
+	lock_super(sb);
+
+	err = msdos_format_name(old_dentry->d_name.name,
+				old_dentry->d_name.len, old_msdos_name,
+				&MSDOS_SB(old_dir->i_sb)->options);
+	if (err)
+		goto out;
+	err = msdos_format_name(new_dentry->d_name.name,
+				new_dentry->d_name.len, new_msdos_name,
+				&MSDOS_SB(new_dir->i_sb)->options);
+	if (err)
+		goto out;
+
+	is_hid =
+	     (new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
+
+	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
+			      new_dir, new_msdos_name, new_dentry, is_hid);
+out:
+	unlock_super(sb);
+	if (!err)
+		err = fat_flush_inodes(sb, old_dir, new_dir);
+	return err;
+}
+
+static const struct inode_operations msdos_dir_inode_operations = {
+	.create		= msdos_create,
+	.lookup		= msdos_lookup,
+	.unlink		= msdos_unlink,
+	.mkdir		= msdos_mkdir,
+	.rmdir		= msdos_rmdir,
+	.rename		= msdos_rename,
+	.setattr	= fat_setattr,
+	.getattr	= fat_getattr,
+};
+
+static int msdos_fill_super(struct super_block *sb, void *data, int silent)
+{
+	int res;
+
+	res = fat_fill_super(sb, data, silent, &msdos_dir_inode_operations, 0);
+	if (res)
+		return res;
+
+	sb->s_flags |= MS_NOATIME;
+	sb->s_root->d_op = &msdos_dentry_operations;
+	return 0;
+}
+
+static int msdos_get_sb(struct file_system_type *fs_type,
+			int flags, const char *dev_name,
+			void *data, struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, msdos_fill_super,
+			   mnt);
+}
+
+static struct file_system_type msdos_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "msdos",
+	.get_sb		= msdos_get_sb,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+static int __init init_msdos_fs(void)
+{
+	return register_filesystem(&msdos_fs_type);
+}
+
+static void __exit exit_msdos_fs(void)
+{
+	unregister_filesystem(&msdos_fs_type);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Werner Almesberger");
+MODULE_DESCRIPTION("MS-DOS filesystem support");
+
+module_init(init_msdos_fs)
+module_exit(exit_msdos_fs)
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
new file mode 100644
index 0000000..155c10b
--- /dev/null
+++ b/fs/fat/namei_vfat.c
@@ -0,0 +1,1055 @@
+/*
+ *  linux/fs/vfat/namei.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *
+ *  Windows95/Windows NT compatible extended MSDOS filesystem
+ *    by Gordon Chaffee Copyright (C) 1995.  Send bug reports for the
+ *    VFAT filesystem to <chaffee@cs.berkeley.edu>.  Specify
+ *    what file operation caused you trouble and if you can duplicate
+ *    the problem, send a script that demonstrates it.
+ *
+ *  Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
+ *
+ *  Support Multibyte characters and cleanup by
+ *				OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
+ */
+
+#include <linux/module.h>
+
+#include <linux/jiffies.h>
+#include <linux/msdos_fs.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <linux/namei.h>
+
+static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	int ret = 1;
+
+	if (!dentry->d_inode &&
+	    nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_CREATE))
+		/*
+		 * negative dentry is dropped, in order to make sure
+		 * to use the name which a user desires if this is
+		 * create path.
+		 */
+		ret = 0;
+	else {
+		spin_lock(&dentry->d_lock);
+		if (dentry->d_time != dentry->d_parent->d_inode->i_version)
+			ret = 0;
+		spin_unlock(&dentry->d_lock);
+	}
+	return ret;
+}
+
+/* returns the length of a struct qstr, ignoring trailing dots */
+static unsigned int vfat_striptail_len(struct qstr *qstr)
+{
+	unsigned int len = qstr->len;
+
+	while (len && qstr->name[len - 1] == '.')
+		len--;
+	return len;
+}
+
+/*
+ * Compute the hash for the vfat name corresponding to the dentry.
+ * Note: if the name is invalid, we leave the hash code unchanged so
+ * that the existing dentry can be used. The vfat fs routines will
+ * return ENOENT or EINVAL as appropriate.
+ */
+static int vfat_hash(struct dentry *dentry, struct qstr *qstr)
+{
+	qstr->hash = full_name_hash(qstr->name, vfat_striptail_len(qstr));
+	return 0;
+}
+
+/*
+ * Compute the hash for the vfat name corresponding to the dentry.
+ * Note: if the name is invalid, we leave the hash code unchanged so
+ * that the existing dentry can be used. The vfat fs routines will
+ * return ENOENT or EINVAL as appropriate.
+ */
+static int vfat_hashi(struct dentry *dentry, struct qstr *qstr)
+{
+	struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+	const unsigned char *name;
+	unsigned int len;
+	unsigned long hash;
+
+	name = qstr->name;
+	len = vfat_striptail_len(qstr);
+
+	hash = init_name_hash();
+	while (len--)
+		hash = partial_name_hash(nls_tolower(t, *name++), hash);
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+/*
+ * Case insensitive compare of two vfat names.
+ */
+static int vfat_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b)
+{
+	struct nls_table *t = MSDOS_SB(dentry->d_inode->i_sb)->nls_io;
+	unsigned int alen, blen;
+
+	/* A filename cannot end in '.' or we treat it like it has none */
+	alen = vfat_striptail_len(a);
+	blen = vfat_striptail_len(b);
+	if (alen == blen) {
+		if (nls_strnicmp(t, a->name, b->name, alen) == 0)
+			return 0;
+	}
+	return 1;
+}
+
+/*
+ * Case sensitive compare of two vfat names.
+ */
+static int vfat_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b)
+{
+	unsigned int alen, blen;
+
+	/* A filename cannot end in '.' or we treat it like it has none */
+	alen = vfat_striptail_len(a);
+	blen = vfat_striptail_len(b);
+	if (alen == blen) {
+		if (strncmp(a->name, b->name, alen) == 0)
+			return 0;
+	}
+	return 1;
+}
+
+static struct dentry_operations vfat_dentry_ops[4] = {
+	{
+		.d_hash		= vfat_hashi,
+		.d_compare	= vfat_cmpi,
+	},
+	{
+		.d_revalidate	= vfat_revalidate,
+		.d_hash		= vfat_hashi,
+		.d_compare	= vfat_cmpi,
+	},
+	{
+		.d_hash		= vfat_hash,
+		.d_compare	= vfat_cmp,
+	},
+	{
+		.d_revalidate	= vfat_revalidate,
+		.d_hash		= vfat_hash,
+		.d_compare	= vfat_cmp,
+	}
+};
+
+/* Characters that are undesirable in an MS-DOS file name */
+
+static inline wchar_t vfat_bad_char(wchar_t w)
+{
+	return (w < 0x0020)
+	    || (w == '*') || (w == '?') || (w == '<') || (w == '>')
+	    || (w == '|') || (w == '"') || (w == ':') || (w == '/')
+	    || (w == '\\');
+}
+
+static inline wchar_t vfat_replace_char(wchar_t w)
+{
+	return (w == '[') || (w == ']') || (w == ';') || (w == ',')
+	    || (w == '+') || (w == '=');
+}
+
+static wchar_t vfat_skip_char(wchar_t w)
+{
+	return (w == '.') || (w == ' ');
+}
+
+static inline int vfat_is_used_badchars(const wchar_t *s, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		if (vfat_bad_char(s[i]))
+			return -EINVAL;
+
+	if (s[i - 1] == ' ') /* last character cannot be space */
+		return -EINVAL;
+
+	return 0;
+}
+
+static int vfat_find_form(struct inode *dir, unsigned char *name)
+{
+	struct fat_slot_info sinfo;
+	int err = fat_scan(dir, name, &sinfo);
+	if (err)
+		return -ENOENT;
+	brelse(sinfo.bh);
+	return 0;
+}
+
+/*
+ * 1) Valid characters for the 8.3 format alias are any combination of
+ * letters, uppercase alphabets, digits, any of the
+ * following special characters:
+ *     $ % ' ` - @ { } ~ ! # ( ) & _ ^
+ * In this case Longfilename is not stored in disk.
+ *
+ * WinNT's Extension:
+ * File name and extension name is contain uppercase/lowercase
+ * only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT.
+ *
+ * 2) File name is 8.3 format, but it contain the uppercase and
+ * lowercase char, muliti bytes char, etc. In this case numtail is not
+ * added, but Longfilename is stored.
+ *
+ * 3) When the one except for the above, or the following special
+ * character are contained:
+ *        .   [ ] ; , + =
+ * numtail is added, and Longfilename must be stored in disk .
+ */
+struct shortname_info {
+	unsigned char lower:1,
+		      upper:1,
+		      valid:1;
+};
+#define INIT_SHORTNAME_INFO(x)	do {		\
+	(x)->lower = 1;				\
+	(x)->upper = 1;				\
+	(x)->valid = 1;				\
+} while (0)
+
+static inline int to_shortname_char(struct nls_table *nls,
+				    unsigned char *buf, int buf_size,
+				    wchar_t *src, struct shortname_info *info)
+{
+	int len;
+
+	if (vfat_skip_char(*src)) {
+		info->valid = 0;
+		return 0;
+	}
+	if (vfat_replace_char(*src)) {
+		info->valid = 0;
+		buf[0] = '_';
+		return 1;
+	}
+
+	len = nls->uni2char(*src, buf, buf_size);
+	if (len <= 0) {
+		info->valid = 0;
+		buf[0] = '_';
+		len = 1;
+	} else if (len == 1) {
+		unsigned char prev = buf[0];
+
+		if (buf[0] >= 0x7F) {
+			info->lower = 0;
+			info->upper = 0;
+		}
+
+		buf[0] = nls_toupper(nls, buf[0]);
+		if (isalpha(buf[0])) {
+			if (buf[0] == prev)
+				info->lower = 0;
+			else
+				info->upper = 0;
+		}
+	} else {
+		info->lower = 0;
+		info->upper = 0;
+	}
+
+	return len;
+}
+
+/*
+ * Given a valid longname, create a unique shortname.  Make sure the
+ * shortname does not exist
+ * Returns negative number on error, 0 for a normal
+ * return, and 1 for valid shortname
+ */
+static int vfat_create_shortname(struct inode *dir, struct nls_table *nls,
+				 wchar_t *uname, int ulen,
+				 unsigned char *name_res, unsigned char *lcase)
+{
+	struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options;
+	wchar_t *ip, *ext_start, *end, *name_start;
+	unsigned char base[9], ext[4], buf[8], *p;
+	unsigned char charbuf[NLS_MAX_CHARSET_SIZE];
+	int chl, chi;
+	int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen;
+	int is_shortname;
+	struct shortname_info base_info, ext_info;
+
+	is_shortname = 1;
+	INIT_SHORTNAME_INFO(&base_info);
+	INIT_SHORTNAME_INFO(&ext_info);
+
+	/* Now, we need to create a shortname from the long name */
+	ext_start = end = &uname[ulen];
+	while (--ext_start >= uname) {
+		if (*ext_start == 0x002E) {	/* is `.' */
+			if (ext_start == end - 1) {
+				sz = ulen;
+				ext_start = NULL;
+			}
+			break;
+		}
+	}
+
+	if (ext_start == uname - 1) {
+		sz = ulen;
+		ext_start = NULL;
+	} else if (ext_start) {
+		/*
+		 * Names which start with a dot could be just
+		 * an extension eg. "...test".  In this case Win95
+		 * uses the extension as the name and sets no extension.
+		 */
+		name_start = &uname[0];
+		while (name_start < ext_start) {
+			if (!vfat_skip_char(*name_start))
+				break;
+			name_start++;
+		}
+		if (name_start != ext_start) {
+			sz = ext_start - uname;
+			ext_start++;
+		} else {
+			sz = ulen;
+			ext_start = NULL;
+		}
+	}
+
+	numtail_baselen = 6;
+	numtail2_baselen = 2;
+	for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) {
+		chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
+					ip, &base_info);
+		if (chl == 0)
+			continue;
+
+		if (baselen < 2 && (baselen + chl) > 2)
+			numtail2_baselen = baselen;
+		if (baselen < 6 && (baselen + chl) > 6)
+			numtail_baselen = baselen;
+		for (chi = 0; chi < chl; chi++) {
+			*p++ = charbuf[chi];
+			baselen++;
+			if (baselen >= 8)
+				break;
+		}
+		if (baselen >= 8) {
+			if ((chi < chl - 1) || (ip + 1) - uname < sz)
+				is_shortname = 0;
+			break;
+		}
+	}
+	if (baselen == 0) {
+		return -EINVAL;
+	}
+
+	extlen = 0;
+	if (ext_start) {
+		for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) {
+			chl = to_shortname_char(nls, charbuf, sizeof(charbuf),
+						ip, &ext_info);
+			if (chl == 0)
+				continue;
+
+			if ((extlen + chl) > 3) {
+				is_shortname = 0;
+				break;
+			}
+			for (chi = 0; chi < chl; chi++) {
+				*p++ = charbuf[chi];
+				extlen++;
+			}
+			if (extlen >= 3) {
+				if (ip + 1 != end)
+					is_shortname = 0;
+				break;
+			}
+		}
+	}
+	ext[extlen] = '\0';
+	base[baselen] = '\0';
+
+	/* Yes, it can happen. ".\xe5" would do it. */
+	if (base[0] == DELETED_FLAG)
+		base[0] = 0x05;
+
+	/* OK, at this point we know that base is not longer than 8 symbols,
+	 * ext is not longer than 3, base is nonempty, both don't contain
+	 * any bad symbols (lowercase transformed to uppercase).
+	 */
+
+	memset(name_res, ' ', MSDOS_NAME);
+	memcpy(name_res, base, baselen);
+	memcpy(name_res + 8, ext, extlen);
+	*lcase = 0;
+	if (is_shortname && base_info.valid && ext_info.valid) {
+		if (vfat_find_form(dir, name_res) == 0)
+			return -EEXIST;
+
+		if (opts->shortname & VFAT_SFN_CREATE_WIN95) {
+			return (base_info.upper && ext_info.upper);
+		} else if (opts->shortname & VFAT_SFN_CREATE_WINNT) {
+			if ((base_info.upper || base_info.lower) &&
+			    (ext_info.upper || ext_info.lower)) {
+				if (!base_info.upper && base_info.lower)
+					*lcase |= CASE_LOWER_BASE;
+				if (!ext_info.upper && ext_info.lower)
+					*lcase |= CASE_LOWER_EXT;
+				return 1;
+			}
+			return 0;
+		} else {
+			BUG();
+		}
+	}
+
+	if (opts->numtail == 0)
+		if (vfat_find_form(dir, name_res) < 0)
+			return 0;
+
+	/*
+	 * Try to find a unique extension.  This used to
+	 * iterate through all possibilities sequentially,
+	 * but that gave extremely bad performance.  Windows
+	 * only tries a few cases before using random
+	 * values for part of the base.
+	 */
+
+	if (baselen > 6) {
+		baselen = numtail_baselen;
+		name_res[7] = ' ';
+	}
+	name_res[baselen] = '~';
+	for (i = 1; i < 10; i++) {
+		name_res[baselen + 1] = i + '0';
+		if (vfat_find_form(dir, name_res) < 0)
+			return 0;
+	}
+
+	i = jiffies & 0xffff;
+	sz = (jiffies >> 16) & 0x7;
+	if (baselen > 2) {
+		baselen = numtail2_baselen;
+		name_res[7] = ' ';
+	}
+	name_res[baselen + 4] = '~';
+	name_res[baselen + 5] = '1' + sz;
+	while (1) {
+		sprintf(buf, "%04X", i);
+		memcpy(&name_res[baselen], buf, 4);
+		if (vfat_find_form(dir, name_res) < 0)
+			break;
+		i -= 11;
+	}
+	return 0;
+}
+
+/* Translate a string, including coded sequences into Unicode */
+static int
+xlate_to_uni(const unsigned char *name, int len, unsigned char *outname,
+	     int *longlen, int *outlen, int escape, int utf8,
+	     struct nls_table *nls)
+{
+	const unsigned char *ip;
+	unsigned char nc;
+	unsigned char *op;
+	unsigned int ec;
+	int i, k, fill;
+	int charlen;
+
+	if (utf8) {
+		int name_len = strlen(name);
+
+		*outlen = utf8_mbstowcs((wchar_t *)outname, name, PATH_MAX);
+
+		/*
+		 * We stripped '.'s before and set len appropriately,
+		 * but utf8_mbstowcs doesn't care about len
+		 */
+		*outlen -= (name_len - len);
+
+		if (*outlen > 255)
+			return -ENAMETOOLONG;
+
+		op = &outname[*outlen * sizeof(wchar_t)];
+	} else {
+		if (nls) {
+			for (i = 0, ip = name, op = outname, *outlen = 0;
+			     i < len && *outlen <= 255;
+			     *outlen += 1)
+			{
+				if (escape && (*ip == ':')) {
+					if (i > len - 5)
+						return -EINVAL;
+					ec = 0;
+					for (k = 1; k < 5; k++) {
+						nc = ip[k];
+						ec <<= 4;
+						if (nc >= '0' && nc <= '9') {
+							ec |= nc - '0';
+							continue;
+						}
+						if (nc >= 'a' && nc <= 'f') {
+							ec |= nc - ('a' - 10);
+							continue;
+						}
+						if (nc >= 'A' && nc <= 'F') {
+							ec |= nc - ('A' - 10);
+							continue;
+						}
+						return -EINVAL;
+					}
+					*op++ = ec & 0xFF;
+					*op++ = ec >> 8;
+					ip += 5;
+					i += 5;
+				} else {
+					if ((charlen = nls->char2uni(ip, len - i, (wchar_t *)op)) < 0)
+						return -EINVAL;
+					ip += charlen;
+					i += charlen;
+					op += 2;
+				}
+			}
+			if (i < len)
+				return -ENAMETOOLONG;
+		} else {
+			for (i = 0, ip = name, op = outname, *outlen = 0;
+			     i < len && *outlen <= 255;
+			     i++, *outlen += 1)
+			{
+				*op++ = *ip++;
+				*op++ = 0;
+			}
+			if (i < len)
+				return -ENAMETOOLONG;
+		}
+	}
+
+	*longlen = *outlen;
+	if (*outlen % 13) {
+		*op++ = 0;
+		*op++ = 0;
+		*outlen += 1;
+		if (*outlen % 13) {
+			fill = 13 - (*outlen % 13);
+			for (i = 0; i < fill; i++) {
+				*op++ = 0xff;
+				*op++ = 0xff;
+			}
+			*outlen += fill;
+		}
+	}
+
+	return 0;
+}
+
+static int vfat_build_slots(struct inode *dir, const unsigned char *name,
+			    int len, int is_dir, int cluster,
+			    struct timespec *ts,
+			    struct msdos_dir_slot *slots, int *nr_slots)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
+	struct fat_mount_options *opts = &sbi->options;
+	struct msdos_dir_slot *ps;
+	struct msdos_dir_entry *de;
+	unsigned char cksum, lcase;
+	unsigned char msdos_name[MSDOS_NAME];
+	wchar_t *uname;
+	__le16 time, date;
+	int err, ulen, usize, i;
+	loff_t offset;
+
+	*nr_slots = 0;
+
+	uname = __getname();
+	if (!uname)
+		return -ENOMEM;
+
+	err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize,
+			   opts->unicode_xlate, opts->utf8, sbi->nls_io);
+	if (err)
+		goto out_free;
+
+	err = vfat_is_used_badchars(uname, ulen);
+	if (err)
+		goto out_free;
+
+	err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen,
+				    msdos_name, &lcase);
+	if (err < 0)
+		goto out_free;
+	else if (err == 1) {
+		de = (struct msdos_dir_entry *)slots;
+		err = 0;
+		goto shortname;
+	}
+
+	/* build the entry of long file name */
+	cksum = fat_checksum(msdos_name);
+
+	*nr_slots = usize / 13;
+	for (ps = slots, i = *nr_slots; i > 0; i--, ps++) {
+		ps->id = i;
+		ps->attr = ATTR_EXT;
+		ps->reserved = 0;
+		ps->alias_checksum = cksum;
+		ps->start = 0;
+		offset = (i - 1) * 13;
+		fatwchar_to16(ps->name0_4, uname + offset, 5);
+		fatwchar_to16(ps->name5_10, uname + offset + 5, 6);
+		fatwchar_to16(ps->name11_12, uname + offset + 11, 2);
+	}
+	slots[0].id |= 0x40;
+	de = (struct msdos_dir_entry *)ps;
+
+shortname:
+	/* build the entry of 8.3 alias name */
+	(*nr_slots)++;
+	memcpy(de->name, msdos_name, MSDOS_NAME);
+	de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
+	de->lcase = lcase;
+	fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
+	de->time = de->ctime = time;
+	de->date = de->cdate = de->adate = date;
+	de->ctime_cs = 0;
+	de->start = cpu_to_le16(cluster);
+	de->starthi = cpu_to_le16(cluster >> 16);
+	de->size = 0;
+out_free:
+	__putname(uname);
+	return err;
+}
+
+static int vfat_add_entry(struct inode *dir, struct qstr *qname, int is_dir,
+			  int cluster, struct timespec *ts,
+			  struct fat_slot_info *sinfo)
+{
+	struct msdos_dir_slot *slots;
+	unsigned int len;
+	int err, nr_slots;
+
+	len = vfat_striptail_len(qname);
+	if (len == 0)
+		return -ENOENT;
+
+	slots = kmalloc(sizeof(*slots) * MSDOS_SLOTS, GFP_NOFS);
+	if (slots == NULL)
+		return -ENOMEM;
+
+	err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts,
+			       slots, &nr_slots);
+	if (err)
+		goto cleanup;
+
+	err = fat_add_entries(dir, slots, nr_slots, sinfo);
+	if (err)
+		goto cleanup;
+
+	/* update timestamp */
+	dir->i_ctime = dir->i_mtime = dir->i_atime = *ts;
+	if (IS_DIRSYNC(dir))
+		(void)fat_sync_inode(dir);
+	else
+		mark_inode_dirty(dir);
+cleanup:
+	kfree(slots);
+	return err;
+}
+
+static int vfat_find(struct inode *dir, struct qstr *qname,
+		     struct fat_slot_info *sinfo)
+{
+	unsigned int len = vfat_striptail_len(qname);
+	if (len == 0)
+		return -ENOENT;
+	return fat_search_long(dir, qname->name, len, sinfo);
+}
+
+static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
+				  struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	struct inode *inode = NULL;
+	struct dentry *alias;
+	int err, table;
+
+	lock_super(sb);
+	table = (MSDOS_SB(sb)->options.name_check == 's') ? 2 : 0;
+	dentry->d_op = &vfat_dentry_ops[table];
+
+	err = vfat_find(dir, &dentry->d_name, &sinfo);
+	if (err) {
+		table++;
+		goto error;
+	}
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		unlock_super(sb);
+		return ERR_CAST(inode);
+	}
+	alias = d_find_alias(inode);
+	if (alias) {
+		if (d_invalidate(alias) == 0)
+			dput(alias);
+		else {
+			iput(inode);
+			unlock_super(sb);
+			return alias;
+		}
+
+	}
+error:
+	unlock_super(sb);
+	dentry->d_op = &vfat_dentry_ops[table];
+	dentry->d_time = dentry->d_parent->d_inode->i_version;
+	dentry = d_splice_alias(inode, dentry);
+	if (dentry) {
+		dentry->d_op = &vfat_dentry_ops[table];
+		dentry->d_time = dentry->d_parent->d_inode->i_version;
+	}
+	return dentry;
+}
+
+static int vfat_create(struct inode *dir, struct dentry *dentry, int mode,
+		       struct nameidata *nd)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct fat_slot_info sinfo;
+	struct timespec ts;
+	int err;
+
+	lock_super(sb);
+
+	ts = CURRENT_TIME_SEC;
+	err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo);
+	if (err)
+		goto out;
+	dir->i_version++;
+
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto out;
+	}
+	inode->i_version++;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	dentry->d_time = dentry->d_parent->d_inode->i_version;
+	d_instantiate(dentry, inode);
+out:
+	unlock_super(sb);
+	return err;
+}
+
+static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_super(sb);
+
+	err = fat_dir_empty(inode);
+	if (err)
+		goto out;
+	err = vfat_find(dir, &dentry->d_name, &sinfo);
+	if (err)
+		goto out;
+
+	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
+	if (err)
+		goto out;
+	drop_nlink(dir);
+
+	clear_nlink(inode);
+	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_super(sb);
+
+	return err;
+}
+
+static int vfat_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = dentry->d_inode;
+	struct super_block *sb = dir->i_sb;
+	struct fat_slot_info sinfo;
+	int err;
+
+	lock_super(sb);
+
+	err = vfat_find(dir, &dentry->d_name, &sinfo);
+	if (err)
+		goto out;
+
+	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
+	if (err)
+		goto out;
+	clear_nlink(inode);
+	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
+	fat_detach(inode);
+out:
+	unlock_super(sb);
+
+	return err;
+}
+
+static int vfat_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode;
+	struct fat_slot_info sinfo;
+	struct timespec ts;
+	int err, cluster;
+
+	lock_super(sb);
+
+	ts = CURRENT_TIME_SEC;
+	cluster = fat_alloc_new_dir(dir, &ts);
+	if (cluster < 0) {
+		err = cluster;
+		goto out;
+	}
+	err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo);
+	if (err)
+		goto out_free;
+	dir->i_version++;
+	inc_nlink(dir);
+
+	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
+	brelse(sinfo.bh);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		/* the directory was completed, just return a error */
+		goto out;
+	}
+	inode->i_version++;
+	inode->i_nlink = 2;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
+	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
+
+	dentry->d_time = dentry->d_parent->d_inode->i_version;
+	d_instantiate(dentry, inode);
+
+	unlock_super(sb);
+	return 0;
+
+out_free:
+	fat_free_clusters(dir, cluster);
+out:
+	unlock_super(sb);
+	return err;
+}
+
+static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
+		       struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct buffer_head *dotdot_bh;
+	struct msdos_dir_entry *dotdot_de;
+	struct inode *old_inode, *new_inode;
+	struct fat_slot_info old_sinfo, sinfo;
+	struct timespec ts;
+	loff_t dotdot_i_pos, new_i_pos;
+	int err, is_dir, update_dotdot, corrupt = 0;
+	struct super_block *sb = old_dir->i_sb;
+
+	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
+	old_inode = old_dentry->d_inode;
+	new_inode = new_dentry->d_inode;
+	lock_super(sb);
+	err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo);
+	if (err)
+		goto out;
+
+	is_dir = S_ISDIR(old_inode->i_mode);
+	update_dotdot = (is_dir && old_dir != new_dir);
+	if (update_dotdot) {
+		if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de,
+					 &dotdot_i_pos) < 0) {
+			err = -EIO;
+			goto out;
+		}
+	}
+
+	ts = CURRENT_TIME_SEC;
+	if (new_inode) {
+		if (is_dir) {
+			err = fat_dir_empty(new_inode);
+			if (err)
+				goto out;
+		}
+		new_i_pos = MSDOS_I(new_inode)->i_pos;
+		fat_detach(new_inode);
+	} else {
+		err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0,
+				     &ts, &sinfo);
+		if (err)
+			goto out;
+		new_i_pos = sinfo.i_pos;
+	}
+	new_dir->i_version++;
+
+	fat_detach(old_inode);
+	fat_attach(old_inode, new_i_pos);
+	if (IS_DIRSYNC(new_dir)) {
+		err = fat_sync_inode(old_inode);
+		if (err)
+			goto error_inode;
+	} else
+		mark_inode_dirty(old_inode);
+
+	if (update_dotdot) {
+		int start = MSDOS_I(new_dir)->i_logstart;
+		dotdot_de->start = cpu_to_le16(start);
+		dotdot_de->starthi = cpu_to_le16(start >> 16);
+		mark_buffer_dirty(dotdot_bh);
+		if (IS_DIRSYNC(new_dir)) {
+			err = sync_dirty_buffer(dotdot_bh);
+			if (err)
+				goto error_dotdot;
+		}
+		drop_nlink(old_dir);
+		if (!new_inode)
+ 			inc_nlink(new_dir);
+	}
+
+	err = fat_remove_entries(old_dir, &old_sinfo);	/* and releases bh */
+	old_sinfo.bh = NULL;
+	if (err)
+		goto error_dotdot;
+	old_dir->i_version++;
+	old_dir->i_ctime = old_dir->i_mtime = ts;
+	if (IS_DIRSYNC(old_dir))
+		(void)fat_sync_inode(old_dir);
+	else
+		mark_inode_dirty(old_dir);
+
+	if (new_inode) {
+		drop_nlink(new_inode);
+		if (is_dir)
+			drop_nlink(new_inode);
+		new_inode->i_ctime = ts;
+	}
+out:
+	brelse(sinfo.bh);
+	brelse(dotdot_bh);
+	brelse(old_sinfo.bh);
+	unlock_super(sb);
+
+	return err;
+
+error_dotdot:
+	/* data cluster is shared, serious corruption */
+	corrupt = 1;
+
+	if (update_dotdot) {
+		int start = MSDOS_I(old_dir)->i_logstart;
+		dotdot_de->start = cpu_to_le16(start);
+		dotdot_de->starthi = cpu_to_le16(start >> 16);
+		mark_buffer_dirty(dotdot_bh);
+		corrupt |= sync_dirty_buffer(dotdot_bh);
+	}
+error_inode:
+	fat_detach(old_inode);
+	fat_attach(old_inode, old_sinfo.i_pos);
+	if (new_inode) {
+		fat_attach(new_inode, new_i_pos);
+		if (corrupt)
+			corrupt |= fat_sync_inode(new_inode);
+	} else {
+		/*
+		 * If new entry was not sharing the data cluster, it
+		 * shouldn't be serious corruption.
+		 */
+		int err2 = fat_remove_entries(new_dir, &sinfo);
+		if (corrupt)
+			corrupt |= err2;
+		sinfo.bh = NULL;
+	}
+	if (corrupt < 0) {
+		fat_fs_panic(new_dir->i_sb,
+			     "%s: Filesystem corrupted (i_pos %lld)",
+			     __func__, sinfo.i_pos);
+	}
+	goto out;
+}
+
+static const struct inode_operations vfat_dir_inode_operations = {
+	.create		= vfat_create,
+	.lookup		= vfat_lookup,
+	.unlink		= vfat_unlink,
+	.mkdir		= vfat_mkdir,
+	.rmdir		= vfat_rmdir,
+	.rename		= vfat_rename,
+	.setattr	= fat_setattr,
+	.getattr	= fat_getattr,
+};
+
+static int vfat_fill_super(struct super_block *sb, void *data, int silent)
+{
+	int res;
+
+	res = fat_fill_super(sb, data, silent, &vfat_dir_inode_operations, 1);
+	if (res)
+		return res;
+
+	if (MSDOS_SB(sb)->options.name_check != 's')
+		sb->s_root->d_op = &vfat_dentry_ops[0];
+	else
+		sb->s_root->d_op = &vfat_dentry_ops[2];
+
+	return 0;
+}
+
+static int vfat_get_sb(struct file_system_type *fs_type,
+		       int flags, const char *dev_name,
+		       void *data, struct vfsmount *mnt)
+{
+	return get_sb_bdev(fs_type, flags, dev_name, data, vfat_fill_super,
+			   mnt);
+}
+
+static struct file_system_type vfat_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "vfat",
+	.get_sb		= vfat_get_sb,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+
+static int __init init_vfat_fs(void)
+{
+	return register_filesystem(&vfat_fs_type);
+}
+
+static void __exit exit_vfat_fs(void)
+{
+	unregister_filesystem(&vfat_fs_type);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("VFAT filesystem support");
+MODULE_AUTHOR("Gordon Chaffee");
+
+module_init(init_vfat_fs)
+module_exit(exit_vfat_fs)