[mirror_ubuntu-artful-kernel.git] / fs / fat / namei_msdos.c

/*
 *  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 "fat.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(const 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(dentry, 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(const struct dentry *parent, const struct dentry *dentry,
		unsigned int len, const char *str, const struct qstr *name)
{
	struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
	int error;

	error = msdos_format_name(name->name, name->len, a_msdos_name, options);
	if (error)
		goto old_compare;
	error = msdos_format_name(str, 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 (name->len == len)
		error = memcmp(name->name, str, len);
	goto out;
}

static const 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,
				   unsigned int flags)
{
	struct super_block *sb = dir->i_sb;
	struct fat_slot_info sinfo;
	struct inode *inode;
	int err;

	mutex_lock(&MSDOS_SB(sb)->s_lock);
	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	switch (err) {
	case -ENOENT:
		inode = NULL;
		break;
	case 0:
		inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
		brelse(sinfo.bh);
		break;
	default:
		inode = ERR_PTR(err);
	}
	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	return d_splice_alias(inode, dentry);
}

/***** 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_time_unix2fat(sbi, ts, &time, &date, NULL);
	de.cdate = de.adate = 0;
	de.ctime = 0;
	de.ctime_cs = 0;
	de.time = time;
	de.date = date;
	fat_set_start(&de, cluster);
	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, umode_t mode,
			bool excl)
{
	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;

	mutex_lock(&MSDOS_SB(sb)->s_lock);

	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:
	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	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 = d_inode(dentry);
	struct fat_slot_info sinfo;
	int err;

	mutex_lock(&MSDOS_SB(sb)->s_lock);
	/*
	 * 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:
	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	if (!err)
		err = fat_flush_inodes(sb, dir, inode);

	return err;
}

/***** Make a directory */
static int msdos_mkdir(struct inode *dir, struct dentry *dentry, umode_t 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;

	mutex_lock(&MSDOS_SB(sb)->s_lock);

	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;
	}
	set_nlink(inode, 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);

	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	fat_flush_inodes(sb, dir, inode);
	return 0;

out_free:
	fat_free_clusters(dir, cluster);
out:
	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	return err;
}

/***** Unlink a file */
static int msdos_unlink(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = d_inode(dentry);
	struct super_block *sb = inode->i_sb;
	struct fat_slot_info sinfo;
	int err;

	mutex_lock(&MSDOS_SB(sb)->s_lock);
	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:
	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	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 new_i_pos;
	int err, old_attrs, is_dir, update_dotdot, corrupt = 0;

	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
	old_inode = d_inode(old_dentry);
	new_inode = d_inode(new_dentry);

	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)) {
			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) {
		fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
		mark_buffer_dirty_inode(dotdot_bh, old_inode);
		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) {
		fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
		mark_buffer_dirty_inode(dotdot_bh, old_inode);
		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_error(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;

	mutex_lock(&MSDOS_SB(sb)->s_lock);

	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:
	mutex_unlock(&MSDOS_SB(sb)->s_lock);
	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 void setup(struct super_block *sb)
{
	MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
	sb->s_d_op = &msdos_dentry_operations;
	sb->s_flags |= MS_NOATIME;
}

static int msdos_fill_super(struct super_block *sb, void *data, int silent)
{
	return fat_fill_super(sb, data, silent, 0, setup);
}

static struct dentry *msdos_mount(struct file_system_type *fs_type,
			int flags, const char *dev_name,
			void *data)
{
	return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
}

static struct file_system_type msdos_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "msdos",
	.mount		= msdos_mount,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("msdos");

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)
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/msdos/namei.c
	3	*
	4	* Written 1992,1993 by Werner Almesberger
	5	* Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
	6	* Rewritten for constant inumbers 1999 by Al Viro
	7	*/
	8
	9	#include <linux/module.h>
9e975dae	10	#include "fat.h"
1da177e4	11
1da177e4 LT	12	/* Characters that are undesirable in an MS-DOS file name */
1da177e4 LT	13	static unsigned char bad_chars[] = "*?<>\|\"";
7557bc66	14	static unsigned char bad_if_strict[] = "+=,; ";
1da177e4 LT	15
	16	/***** Formats an MS-DOS file name. Rejects invalid names. */
	17	static int msdos_format_name(const unsigned char *name, int len,
	18	unsigned char res, struct fat_mount_options opts)
	19	/*
	20	* name is the proposed name, len is its length, res is
	21	* the resulting name, opts->name_check is either (r)elaxed,
	22	* (n)ormal or (s)trict, opts->dotsOK allows dots at the
	23	* beginning of name (for hidden files)
	24	*/
	25	{
	26	unsigned char *walk;
1da177e4 LT	27	unsigned char c;
	28	int space;
	29
	30	if (name[0] == '.') { /* dotfile because . and .. already done */
	31	if (opts->dotsOK) {
	32	/* Get rid of dot - test for it elsewhere */
	33	name++;
	34	len--;
7557bc66	35	} else
1da177e4 LT	36	return -EINVAL;
	37	}
	38	/*
7557bc66	39	* disallow names that _really_ start with a dot
1da177e4	40	*/
7557bc66	41	space = 1;
1da177e4 LT	42	c = 0;
	43	for (walk = res; len && walk - res < 8; walk++) {
	44	c = *name++;
	45	len--;
	46	if (opts->name_check != 'r' && strchr(bad_chars, c))
	47	return -EINVAL;
7557bc66	48	if (opts->name_check == 's' && strchr(bad_if_strict, c))
1da177e4 LT	49	return -EINVAL;
	50	if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
	51	return -EINVAL;
	52	if (c < ' ' \|\| c == ':' \|\| c == '\\')
	53	return -EINVAL;
	54	/*
	55	* 0xE5 is legal as a first character, but we must substitute
	56	* 0x05 because 0xE5 marks deleted files. Yes, DOS really
	57	* does this.
	58	* It seems that Microsoft hacked DOS to support non-US
	59	* characters after the 0xE5 character was already in use to
	60	* mark deleted files.
	61	*/
	62	if ((res == walk) && (c == 0xE5))
	63	c = 0x05;
	64	if (c == '.')
	65	break;
	66	space = (c == ' ');
	67	*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
	68	}
	69	if (space)
	70	return -EINVAL;
	71	if (opts->name_check == 's' && len && c != '.') {
	72	c = *name++;
	73	len--;
	74	if (c != '.')
	75	return -EINVAL;
	76	}
	77	while (c != '.' && len--)
	78	c = *name++;
	79	if (c == '.') {
	80	while (walk - res < 8)
	81	*walk++ = ' ';
	82	while (len > 0 && walk - res < MSDOS_NAME) {
	83	c = *name++;
	84	len--;
	85	if (opts->name_check != 'r' && strchr(bad_chars, c))
	86	return -EINVAL;
	87	if (opts->name_check == 's' &&
7557bc66	88	strchr(bad_if_strict, c))
1da177e4 LT	89	return -EINVAL;
	90	if (c < ' ' \|\| c == ':' \|\| c == '\\')
	91	return -EINVAL;
	92	if (c == '.') {
	93	if (opts->name_check == 's')
	94	return -EINVAL;
	95	break;
	96	}
	97	if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
	98	return -EINVAL;
	99	space = c == ' ';
	100	if (!opts->nocase && c >= 'a' && c <= 'z')
	101	*walk++ = c - 32;
	102	else
	103	*walk++ = c;
	104	}
	105	if (space)
	106	return -EINVAL;
	107	if (opts->name_check == 's' && len)
	108	return -EINVAL;
	109	}
	110	while (walk - res < MSDOS_NAME)
	111	*walk++ = ' ';
094e320d	112
1da177e4 LT	113	return 0;
	114	}
	115
	116	/***** Locates a directory entry. Uses unformatted name. */
	117	static int msdos_find(struct inode dir, const unsigned char name, int len,
	118	struct fat_slot_info *sinfo)
	119	{
	120	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
	121	unsigned char msdos_name[MSDOS_NAME];
	122	int err;
	123
	124	err = msdos_format_name(name, len, msdos_name, &sbi->options);
	125	if (err)
	126	return -ENOENT;
	127
	128	err = fat_scan(dir, msdos_name, sinfo);
	129	if (!err && sbi->options.dotsOK) {
	130	if (name[0] == '.') {
	131	if (!(sinfo->de->attr & ATTR_HIDDEN))
	132	err = -ENOENT;
	133	} else {
	134	if (sinfo->de->attr & ATTR_HIDDEN)
	135	err = -ENOENT;
	136	}
	137	if (err)
	138	brelse(sinfo->bh);
	139	}
	140	return err;
	141	}
	142
	143	/*
	144	* Compute the hash for the msdos name corresponding to the dentry.
	145	* Note: if the name is invalid, we leave the hash code unchanged so
	146	* that the existing dentry can be used. The msdos fs routines will
	147	* return ENOENT or EINVAL as appropriate.
	148	*/
da53be12	149	static int msdos_hash(const struct dentry dentry, struct qstr qstr)
1da177e4 LT	150	{
	151	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
	152	unsigned char msdos_name[MSDOS_NAME];
	153	int error;
	154
	155	error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
	156	if (!error)
8387ff25	157	qstr->hash = full_name_hash(dentry, msdos_name, MSDOS_NAME);
1da177e4 LT	158	return 0;
	159	}
	160
	161	/*
	162	* Compare two msdos names. If either of the names are invalid,
	163	* we fall back to doing the standard name comparison.
	164	*/
da53be12	165	static int msdos_cmp(const struct dentry parent, const struct dentry dentry,
621e155a	166	unsigned int len, const char str, const struct qstr name)
1da177e4	167	{
621e155a	168	struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
1da177e4 LT	169	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
	170	int error;
	171
621e155a	172	error = msdos_format_name(name->name, name->len, a_msdos_name, options);
1da177e4 LT	173	if (error)
1da177e4 LT	174	goto old_compare;
621e155a	175	error = msdos_format_name(str, len, b_msdos_name, options);
1da177e4 LT	176	if (error)
	177	goto old_compare;
	178	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
	179	out:
	180	return error;
	181
	182	old_compare:
	183	error = 1;
621e155a NP	184	if (name->len == len)
621e155a NP	185	error = memcmp(name->name, str, len);
1da177e4 LT	186	goto out;
	187	}
	188
ce6cdc47	189	static const struct dentry_operations msdos_dentry_operations = {
1da177e4 LT	190	.d_hash = msdos_hash,
	191	.d_compare = msdos_cmp,
	192	};
	193
	194	/*
	195	* AV. Wrappers for FAT sb operations. Is it wise?
	196	*/
	197
	198	/***** Get inode using directory and name */
	199	static struct dentry msdos_lookup(struct inode dir, struct dentry *dentry,
00cd8dd3	200	unsigned int flags)
1da177e4 LT	201	{
	202	struct super_block *sb = dir->i_sb;
	203	struct fat_slot_info sinfo;
45cfbe35 OH	204	struct inode *inode;
45cfbe35 OH	205	int err;
1da177e4	206
e40b34c7	207	mutex_lock(&MSDOS_SB(sb)->s_lock);
45cfbe35	208	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
a9049376 AV	209	switch (err) {
	210	case -ENOENT:
	211	inode = NULL;
	212	break;
	213	case 0:
	214	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	215	brelse(sinfo.bh);
	216	break;
	217	default:
	218	inode = ERR_PTR(err);
1da177e4	219	}
e40b34c7	220	mutex_unlock(&MSDOS_SB(sb)->s_lock);
3d23985d	221	return d_splice_alias(inode, dentry);
1da177e4 LT	222	}
	223
	224	/***** Creates a directory entry (name is already formatted). */
	225	static int msdos_add_entry(struct inode dir, const unsigned char name,
	226	int is_dir, int is_hid, int cluster,
	227	struct timespec ts, struct fat_slot_info sinfo)
	228	{
b271e067	229	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
1da177e4 LT	230	struct msdos_dir_entry de;
	231	__le16 time, date;
	232	int err;
	233
	234	memcpy(de.name, name, MSDOS_NAME);
	235	de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
	236	if (is_hid)
	237	de.attr \|= ATTR_HIDDEN;
	238	de.lcase = 0;
7decd1cb	239	fat_time_unix2fat(sbi, ts, &time, &date, NULL);
1da177e4 LT	240	de.cdate = de.adate = 0;
	241	de.ctime = 0;
	242	de.ctime_cs = 0;
	243	de.time = time;
	244	de.date = date;
a943ed71	245	fat_set_start(&de, cluster);
1da177e4 LT	246	de.size = 0;
	247
	248	err = fat_add_entries(dir, &de, 1, sinfo);
	249	if (err)
	250	return err;
	251
	252	dir->i_ctime = dir->i_mtime = *ts;
	253	if (IS_DIRSYNC(dir))
	254	(void)fat_sync_inode(dir);
	255	else
	256	mark_inode_dirty(dir);
	257
	258	return 0;
	259	}
	260
	261	/***** Create a file */
4acdaf27	262	static int msdos_create(struct inode dir, struct dentry dentry, umode_t mode,
ebfc3b49	263	bool excl)
1da177e4 LT	264	{
1da177e4 LT	265	struct super_block *sb = dir->i_sb;
ae78bf9c	266	struct inode *inode = NULL;
1da177e4 LT	267	struct fat_slot_info sinfo;
	268	struct timespec ts;
	269	unsigned char msdos_name[MSDOS_NAME];
	270	int err, is_hid;
	271
e40b34c7	272	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	273
	274	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
	275	msdos_name, &MSDOS_SB(sb)->options);
	276	if (err)
	277	goto out;
	278	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
	279	/* Have to do it due to foo vs. .foo conflicts */
	280	if (!fat_scan(dir, msdos_name, &sinfo)) {
	281	brelse(sinfo.bh);
	282	err = -EINVAL;
	283	goto out;
	284	}
	285
	286	ts = CURRENT_TIME_SEC;
	287	err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
	288	if (err)
	289	goto out;
	290	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	291	brelse(sinfo.bh);
	292	if (IS_ERR(inode)) {
	293	err = PTR_ERR(inode);
	294	goto out;
	295	}
	296	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
	297	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
	298
	299	d_instantiate(dentry, inode);
	300	out:
e40b34c7	301	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c CM	302	if (!err)
ae78bf9c CM	303	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	304	return err;
	305	}
	306
	307	/***** Remove a directory */
	308	static int msdos_rmdir(struct inode dir, struct dentry dentry)
	309	{
8f593427	310	struct super_block *sb = dir->i_sb;
2b0143b5	311	struct inode *inode = d_inode(dentry);
1da177e4 LT	312	struct fat_slot_info sinfo;
	313	int err;
	314
e40b34c7	315	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	316	/*
	317	* Check whether the directory is not in use, then check
	318	* whether it is empty.
	319	*/
	320	err = fat_dir_empty(inode);
	321	if (err)
	322	goto out;
	323	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	324	if (err)
	325	goto out;
	326
	327	err = fat_remove_entries(dir, &sinfo); /* and releases bh */
	328	if (err)
	329	goto out;
9a53c3a7	330	drop_nlink(dir);
1da177e4	331
ce71ec36	332	clear_nlink(inode);
1da177e4 LT	333	inode->i_ctime = CURRENT_TIME_SEC;
	334	fat_detach(inode);
	335	out:
e40b34c7	336	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	337	if (!err)
8f593427	338	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	339
	340	return err;
	341	}
	342
	343	/***** Make a directory */
18bb1db3	344	static int msdos_mkdir(struct inode dir, struct dentry dentry, umode_t mode)
1da177e4 LT	345	{
	346	struct super_block *sb = dir->i_sb;
	347	struct fat_slot_info sinfo;
	348	struct inode *inode;
	349	unsigned char msdos_name[MSDOS_NAME];
	350	struct timespec ts;
	351	int err, is_hid, cluster;
	352
e40b34c7	353	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	354
	355	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
	356	msdos_name, &MSDOS_SB(sb)->options);
	357	if (err)
	358	goto out;
	359	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
	360	/* foo vs .foo situation */
	361	if (!fat_scan(dir, msdos_name, &sinfo)) {
	362	brelse(sinfo.bh);
	363	err = -EINVAL;
	364	goto out;
	365	}
	366
	367	ts = CURRENT_TIME_SEC;
	368	cluster = fat_alloc_new_dir(dir, &ts);
	369	if (cluster < 0) {
	370	err = cluster;
	371	goto out;
	372	}
	373	err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
	374	if (err)
	375	goto out_free;
d8c76e6f	376	inc_nlink(dir);
1da177e4 LT	377
	378	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	379	brelse(sinfo.bh);
	380	if (IS_ERR(inode)) {
	381	err = PTR_ERR(inode);
	382	/* the directory was completed, just return a error */
	383	goto out;
	384	}
bfe86848	385	set_nlink(inode, 2);
1da177e4 LT	386	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
	387	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
	388
	389	d_instantiate(dentry, inode);
	390
e40b34c7	391	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	392	fat_flush_inodes(sb, dir, inode);
1da177e4 LT	393	return 0;
	394
	395	out_free:
	396	fat_free_clusters(dir, cluster);
	397	out:
e40b34c7	398	mutex_unlock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	399	return err;
	400	}
	401
	402	/***** Unlink a file */
	403	static int msdos_unlink(struct inode dir, struct dentry dentry)
	404	{
2b0143b5	405	struct inode *inode = d_inode(dentry);
85cb9bf5	406	struct super_block *sb = inode->i_sb;
1da177e4 LT	407	struct fat_slot_info sinfo;
	408	int err;
	409
e40b34c7	410	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	411	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	412	if (err)
	413	goto out;
	414
	415	err = fat_remove_entries(dir, &sinfo); /* and releases bh */
	416	if (err)
	417	goto out;
ce71ec36	418	clear_nlink(inode);
1da177e4 LT	419	inode->i_ctime = CURRENT_TIME_SEC;
	420	fat_detach(inode);
	421	out:
e40b34c7	422	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	423	if (!err)
8f593427	424	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	425
	426	return err;
	427	}
	428
	429	static int do_msdos_rename(struct inode old_dir, unsigned char old_name,
	430	struct dentry *old_dentry,
	431	struct inode new_dir, unsigned char new_name,
	432	struct dentry *new_dentry, int is_hid)
	433	{
	434	struct buffer_head *dotdot_bh;
	435	struct msdos_dir_entry *dotdot_de;
1da177e4 LT	436	struct inode old_inode, new_inode;
	437	struct fat_slot_info old_sinfo, sinfo;
	438	struct timespec ts;
7669e8fb	439	loff_t new_i_pos;
1da177e4 LT	440	int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
	441
	442	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
2b0143b5 DH	443	old_inode = d_inode(old_dentry);
2b0143b5 DH	444	new_inode = d_inode(new_dentry);
1da177e4 LT	445
	446	err = fat_scan(old_dir, old_name, &old_sinfo);
	447	if (err) {
	448	err = -EIO;
	449	goto out;
	450	}
	451
	452	is_dir = S_ISDIR(old_inode->i_mode);
	453	update_dotdot = (is_dir && old_dir != new_dir);
	454	if (update_dotdot) {
7669e8fb	455	if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
1da177e4 LT	456	err = -EIO;
	457	goto out;
	458	}
	459	}
	460
	461	old_attrs = MSDOS_I(old_inode)->i_attrs;
	462	err = fat_scan(new_dir, new_name, &sinfo);
	463	if (!err) {
	464	if (!new_inode) {
	465	/* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
	466	if (sinfo.de != old_sinfo.de) {
	467	err = -EINVAL;
	468	goto out;
	469	}
	470	if (is_hid)
	471	MSDOS_I(old_inode)->i_attrs \|= ATTR_HIDDEN;
	472	else
	473	MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
	474	if (IS_DIRSYNC(old_dir)) {
	475	err = fat_sync_inode(old_inode);
	476	if (err) {
	477	MSDOS_I(old_inode)->i_attrs = old_attrs;
	478	goto out;
	479	}
	480	} else
	481	mark_inode_dirty(old_inode);
	482
	483	old_dir->i_version++;
	484	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
	485	if (IS_DIRSYNC(old_dir))
	486	(void)fat_sync_inode(old_dir);
	487	else
	488	mark_inode_dirty(old_dir);
	489	goto out;
	490	}
	491	}
	492
	493	ts = CURRENT_TIME_SEC;
	494	if (new_inode) {
	495	if (err)
	496	goto out;
1da177e4 LT	497	if (is_dir) {
	498	err = fat_dir_empty(new_inode);
	499	if (err)
	500	goto out;
	501	}
9131dd42	502	new_i_pos = MSDOS_I(new_inode)->i_pos;
1da177e4 LT	503	fat_detach(new_inode);
	504	} else {
	505	err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
	506	&ts, &sinfo);
	507	if (err)
	508	goto out;
9131dd42	509	new_i_pos = sinfo.i_pos;
1da177e4 LT	510	}
	511	new_dir->i_version++;
	512
	513	fat_detach(old_inode);
9131dd42	514	fat_attach(old_inode, new_i_pos);
1da177e4 LT	515	if (is_hid)
	516	MSDOS_I(old_inode)->i_attrs \|= ATTR_HIDDEN;
	517	else
	518	MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
	519	if (IS_DIRSYNC(new_dir)) {
	520	err = fat_sync_inode(old_inode);
	521	if (err)
	522	goto error_inode;
	523	} else
	524	mark_inode_dirty(old_inode);
	525
	526	if (update_dotdot) {
a943ed71	527	fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
b522412a	528	mark_buffer_dirty_inode(dotdot_bh, old_inode);
1da177e4 LT	529	if (IS_DIRSYNC(new_dir)) {
	530	err = sync_dirty_buffer(dotdot_bh);
	531	if (err)
	532	goto error_dotdot;
	533	}
9a53c3a7	534	drop_nlink(old_dir);
1da177e4	535	if (!new_inode)
d8c76e6f	536	inc_nlink(new_dir);
1da177e4 LT	537	}
	538
	539	err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
	540	old_sinfo.bh = NULL;
	541	if (err)
	542	goto error_dotdot;
	543	old_dir->i_version++;
	544	old_dir->i_ctime = old_dir->i_mtime = ts;
	545	if (IS_DIRSYNC(old_dir))
	546	(void)fat_sync_inode(old_dir);
	547	else
	548	mark_inode_dirty(old_dir);
	549
	550	if (new_inode) {
9a53c3a7	551	drop_nlink(new_inode);
1da177e4	552	if (is_dir)
9a53c3a7	553	drop_nlink(new_inode);
1da177e4 LT	554	new_inode->i_ctime = ts;
	555	}
	556	out:
	557	brelse(sinfo.bh);
	558	brelse(dotdot_bh);
	559	brelse(old_sinfo.bh);
	560	return err;
	561
	562	error_dotdot:
	563	/* data cluster is shared, serious corruption */
	564	corrupt = 1;
	565
	566	if (update_dotdot) {
a943ed71	567	fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
b522412a	568	mark_buffer_dirty_inode(dotdot_bh, old_inode);
1da177e4 LT	569	corrupt \|= sync_dirty_buffer(dotdot_bh);
	570	}
	571	error_inode:
	572	fat_detach(old_inode);
	573	fat_attach(old_inode, old_sinfo.i_pos);
	574	MSDOS_I(old_inode)->i_attrs = old_attrs;
	575	if (new_inode) {
9131dd42	576	fat_attach(new_inode, new_i_pos);
1da177e4 LT	577	if (corrupt)
	578	corrupt \|= fat_sync_inode(new_inode);
	579	} else {
	580	/*
	581	* If new entry was not sharing the data cluster, it
	582	* shouldn't be serious corruption.
	583	*/
	584	int err2 = fat_remove_entries(new_dir, &sinfo);
	585	if (corrupt)
	586	corrupt \|= err2;
	587	sinfo.bh = NULL;
	588	}
	589	if (corrupt < 0) {
85c78591	590	fat_fs_error(new_dir->i_sb,
1da177e4	591	"%s: Filesystem corrupted (i_pos %lld)",
8e24eea7	592	__func__, sinfo.i_pos);
1da177e4 LT	593	}
	594	goto out;
	595	}
	596
	597	/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
	598	static int msdos_rename(struct inode old_dir, struct dentry old_dentry,
	599	struct inode new_dir, struct dentry new_dentry)
	600	{
8f593427	601	struct super_block *sb = old_dir->i_sb;
1da177e4 LT	602	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
	603	int err, is_hid;
	604
e40b34c7	605	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	606
	607	err = msdos_format_name(old_dentry->d_name.name,
	608	old_dentry->d_name.len, old_msdos_name,
	609	&MSDOS_SB(old_dir->i_sb)->options);
	610	if (err)
	611	goto out;
	612	err = msdos_format_name(new_dentry->d_name.name,
	613	new_dentry->d_name.len, new_msdos_name,
	614	&MSDOS_SB(new_dir->i_sb)->options);
	615	if (err)
	616	goto out;
	617
	618	is_hid =
	619	(new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
	620
	621	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
	622	new_dir, new_msdos_name, new_dentry, is_hid);
	623	out:
e40b34c7	624	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	625	if (!err)
8f593427	626	err = fat_flush_inodes(sb, old_dir, new_dir);
1da177e4 LT	627	return err;
	628	}
	629
92e1d5be	630	static const struct inode_operations msdos_dir_inode_operations = {
1da177e4 LT	631	.create = msdos_create,
	632	.lookup = msdos_lookup,
	633	.unlink = msdos_unlink,
	634	.mkdir = msdos_mkdir,
	635	.rmdir = msdos_rmdir,
	636	.rename = msdos_rename,
1278fdd3	637	.setattr = fat_setattr,
da63fc7c	638	.getattr = fat_getattr,
1da177e4 LT	639	};
1da177e4 LT	640
3d23985d	641	static void setup(struct super_block *sb)
1da177e4	642	{
384f5c96	643	MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
3d23985d	644	sb->s_d_op = &msdos_dentry_operations;
1da177e4	645	sb->s_flags \|= MS_NOATIME;
3d23985d AV	646	}
	647
	648	static int msdos_fill_super(struct super_block sb, void data, int silent)
	649	{
384f5c96	650	return fat_fill_super(sb, data, silent, 0, setup);
1da177e4 LT	651	}
1da177e4 LT	652
152a0836	653	static struct dentry msdos_mount(struct file_system_type fs_type,
454e2398	654	int flags, const char *dev_name,
152a0836	655	void *data)
1da177e4	656	{
152a0836	657	return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
1da177e4 LT	658	}
	659
	660	static struct file_system_type msdos_fs_type = {
	661	.owner = THIS_MODULE,
	662	.name = "msdos",
152a0836	663	.mount = msdos_mount,
1da177e4 LT	664	.kill_sb = kill_block_super,
	665	.fs_flags = FS_REQUIRES_DEV,
	666	};
7f78e035	667	MODULE_ALIAS_FS("msdos");
1da177e4 LT	668
	669	static int __init init_msdos_fs(void)
	670	{
	671	return register_filesystem(&msdos_fs_type);
	672	}
	673
	674	static void __exit exit_msdos_fs(void)
	675	{
	676	unregister_filesystem(&msdos_fs_type);
	677	}
	678
	679	MODULE_LICENSE("GPL");
	680	MODULE_AUTHOR("Werner Almesberger");
	681	MODULE_DESCRIPTION("MS-DOS filesystem support");
	682
	683	module_init(init_msdos_fs)
	684	module_exit(exit_msdos_fs)