[linux.git] / fs / fat / namei_msdos.c

/*
 *  linux/fs/msdos/namei.c
 *
 *  Written 1992,1993 by Werner Almesberger
 *  Hidden files 1995 by Albert Cahalan <[email protected]> <[email protected]>
 *  Rewritten for constant inumbers 1999 by Al Viro
 */

#include <linux/module.h>
#include <linux/iversion.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 *dentry,
		unsigned int len, const char *str, const struct qstr *name)
{
	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(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 timespec64 *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 timespec64 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(dir);
	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);
	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(inode);
	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 timespec64 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(dir);
	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(inode);
	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 timespec64 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);

			inode_inc_iversion(old_dir);
			old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
			if (IS_DIRSYNC(old_dir))
				(void)fat_sync_inode(old_dir);
			else
				mark_inode_dirty(old_dir);
			goto out;
		}
	}

	ts = current_time(old_inode);
	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;
	}
	inode_inc_iversion(new_dir);

	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;
	inode_inc_iversion(old_dir);
	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,
			unsigned int flags)
{
	struct super_block *sb = old_dir->i_sb;
	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
	int err, is_hid;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

	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 |= SB_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 <[email protected]> <[email protected]>
	6	* Rewritten for constant inumbers 1999 by Al Viro
	7	*/
	8
	9	#include <linux/module.h>
2489dbab	10	#include <linux/iversion.h>
9e975dae	11	#include "fat.h"
1da177e4	12
1da177e4 LT	13	/* Characters that are undesirable in an MS-DOS file name */
1da177e4 LT	14	static unsigned char bad_chars[] = "*?<>\|\"";
7557bc66	15	static unsigned char bad_if_strict[] = "+=,; ";
1da177e4 LT	16
	17	/***** Formats an MS-DOS file name. Rejects invalid names. */
	18	static int msdos_format_name(const unsigned char *name, int len,
	19	unsigned char res, struct fat_mount_options opts)
	20	/*
	21	* name is the proposed name, len is its length, res is
	22	* the resulting name, opts->name_check is either (r)elaxed,
	23	* (n)ormal or (s)trict, opts->dotsOK allows dots at the
	24	* beginning of name (for hidden files)
	25	*/
	26	{
	27	unsigned char *walk;
1da177e4 LT	28	unsigned char c;
	29	int space;
	30
	31	if (name[0] == '.') { /* dotfile because . and .. already done */
	32	if (opts->dotsOK) {
	33	/* Get rid of dot - test for it elsewhere */
	34	name++;
	35	len--;
7557bc66	36	} else
1da177e4 LT	37	return -EINVAL;
	38	}
	39	/*
7557bc66	40	* disallow names that _really_ start with a dot
1da177e4	41	*/
7557bc66	42	space = 1;
1da177e4 LT	43	c = 0;
	44	for (walk = res; len && walk - res < 8; walk++) {
	45	c = *name++;
	46	len--;
	47	if (opts->name_check != 'r' && strchr(bad_chars, c))
	48	return -EINVAL;
7557bc66	49	if (opts->name_check == 's' && strchr(bad_if_strict, c))
1da177e4 LT	50	return -EINVAL;
	51	if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
	52	return -EINVAL;
	53	if (c < ' ' \|\| c == ':' \|\| c == '\\')
	54	return -EINVAL;
	55	/*
	56	* 0xE5 is legal as a first character, but we must substitute
	57	* 0x05 because 0xE5 marks deleted files. Yes, DOS really
	58	* does this.
	59	* It seems that Microsoft hacked DOS to support non-US
	60	* characters after the 0xE5 character was already in use to
	61	* mark deleted files.
	62	*/
	63	if ((res == walk) && (c == 0xE5))
	64	c = 0x05;
	65	if (c == '.')
	66	break;
	67	space = (c == ' ');
	68	*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
	69	}
	70	if (space)
	71	return -EINVAL;
	72	if (opts->name_check == 's' && len && c != '.') {
	73	c = *name++;
	74	len--;
	75	if (c != '.')
	76	return -EINVAL;
	77	}
	78	while (c != '.' && len--)
	79	c = *name++;
	80	if (c == '.') {
	81	while (walk - res < 8)
	82	*walk++ = ' ';
	83	while (len > 0 && walk - res < MSDOS_NAME) {
	84	c = *name++;
	85	len--;
	86	if (opts->name_check != 'r' && strchr(bad_chars, c))
	87	return -EINVAL;
	88	if (opts->name_check == 's' &&
7557bc66	89	strchr(bad_if_strict, c))
1da177e4 LT	90	return -EINVAL;
	91	if (c < ' ' \|\| c == ':' \|\| c == '\\')
	92	return -EINVAL;
	93	if (c == '.') {
	94	if (opts->name_check == 's')
	95	return -EINVAL;
	96	break;
	97	}
	98	if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
	99	return -EINVAL;
	100	space = c == ' ';
	101	if (!opts->nocase && c >= 'a' && c <= 'z')
	102	*walk++ = c - 32;
	103	else
	104	*walk++ = c;
	105	}
	106	if (space)
	107	return -EINVAL;
	108	if (opts->name_check == 's' && len)
	109	return -EINVAL;
	110	}
	111	while (walk - res < MSDOS_NAME)
	112	*walk++ = ' ';
094e320d	113
1da177e4 LT	114	return 0;
	115	}
	116
	117	/***** Locates a directory entry. Uses unformatted name. */
	118	static int msdos_find(struct inode dir, const unsigned char name, int len,
	119	struct fat_slot_info *sinfo)
	120	{
	121	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
	122	unsigned char msdos_name[MSDOS_NAME];
	123	int err;
	124
	125	err = msdos_format_name(name, len, msdos_name, &sbi->options);
	126	if (err)
	127	return -ENOENT;
	128
	129	err = fat_scan(dir, msdos_name, sinfo);
	130	if (!err && sbi->options.dotsOK) {
	131	if (name[0] == '.') {
	132	if (!(sinfo->de->attr & ATTR_HIDDEN))
	133	err = -ENOENT;
	134	} else {
	135	if (sinfo->de->attr & ATTR_HIDDEN)
	136	err = -ENOENT;
	137	}
	138	if (err)
	139	brelse(sinfo->bh);
	140	}
	141	return err;
	142	}
	143
	144	/*
	145	* Compute the hash for the msdos name corresponding to the dentry.
	146	* Note: if the name is invalid, we leave the hash code unchanged so
	147	* that the existing dentry can be used. The msdos fs routines will
	148	* return ENOENT or EINVAL as appropriate.
	149	*/
da53be12	150	static int msdos_hash(const struct dentry dentry, struct qstr qstr)
1da177e4 LT	151	{
	152	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
	153	unsigned char msdos_name[MSDOS_NAME];
	154	int error;
	155
	156	error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
	157	if (!error)
8387ff25	158	qstr->hash = full_name_hash(dentry, msdos_name, MSDOS_NAME);
1da177e4 LT	159	return 0;
	160	}
	161
	162	/*
	163	* Compare two msdos names. If either of the names are invalid,
	164	* we fall back to doing the standard name comparison.
	165	*/
6fa67e70	166	static int msdos_cmp(const struct dentry *dentry,
621e155a	167	unsigned int len, const char str, const struct qstr name)
1da177e4	168	{
d3fe1985	169	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
1da177e4 LT	170	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
	171	int error;
	172
621e155a	173	error = msdos_format_name(name->name, name->len, a_msdos_name, options);
1da177e4 LT	174	if (error)
1da177e4 LT	175	goto old_compare;
621e155a	176	error = msdos_format_name(str, len, b_msdos_name, options);
1da177e4 LT	177	if (error)
	178	goto old_compare;
	179	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
	180	out:
	181	return error;
	182
	183	old_compare:
	184	error = 1;
621e155a NP	185	if (name->len == len)
621e155a NP	186	error = memcmp(name->name, str, len);
1da177e4 LT	187	goto out;
	188	}
	189
ce6cdc47	190	static const struct dentry_operations msdos_dentry_operations = {
1da177e4 LT	191	.d_hash = msdos_hash,
	192	.d_compare = msdos_cmp,
	193	};
	194
	195	/*
	196	* AV. Wrappers for FAT sb operations. Is it wise?
	197	*/
	198
	199	/***** Get inode using directory and name */
	200	static struct dentry msdos_lookup(struct inode dir, struct dentry *dentry,
00cd8dd3	201	unsigned int flags)
1da177e4 LT	202	{
	203	struct super_block *sb = dir->i_sb;
	204	struct fat_slot_info sinfo;
45cfbe35 OH	205	struct inode *inode;
45cfbe35 OH	206	int err;
1da177e4	207
e40b34c7	208	mutex_lock(&MSDOS_SB(sb)->s_lock);
45cfbe35	209	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
a9049376 AV	210	switch (err) {
	211	case -ENOENT:
	212	inode = NULL;
	213	break;
	214	case 0:
	215	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	216	brelse(sinfo.bh);
	217	break;
	218	default:
	219	inode = ERR_PTR(err);
1da177e4	220	}
e40b34c7	221	mutex_unlock(&MSDOS_SB(sb)->s_lock);
3d23985d	222	return d_splice_alias(inode, dentry);
1da177e4 LT	223	}
	224
	225	/***** Creates a directory entry (name is already formatted). */
	226	static int msdos_add_entry(struct inode dir, const unsigned char name,
	227	int is_dir, int is_hid, int cluster,
f423420c	228	struct timespec64 ts, struct fat_slot_info sinfo)
1da177e4	229	{
b271e067	230	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
1da177e4 LT	231	struct msdos_dir_entry de;
	232	__le16 time, date;
	233	int err;
	234
	235	memcpy(de.name, name, MSDOS_NAME);
	236	de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
	237	if (is_hid)
	238	de.attr \|= ATTR_HIDDEN;
	239	de.lcase = 0;
7decd1cb	240	fat_time_unix2fat(sbi, ts, &time, &date, NULL);
1da177e4 LT	241	de.cdate = de.adate = 0;
	242	de.ctime = 0;
	243	de.ctime_cs = 0;
	244	de.time = time;
	245	de.date = date;
a943ed71	246	fat_set_start(&de, cluster);
1da177e4 LT	247	de.size = 0;
	248
	249	err = fat_add_entries(dir, &de, 1, sinfo);
	250	if (err)
	251	return err;
	252
f423420c	253	dir->i_ctime = dir->i_mtime = *ts;
1da177e4 LT	254	if (IS_DIRSYNC(dir))
	255	(void)fat_sync_inode(dir);
	256	else
	257	mark_inode_dirty(dir);
	258
	259	return 0;
	260	}
	261
	262	/***** Create a file */
4acdaf27	263	static int msdos_create(struct inode dir, struct dentry dentry, umode_t mode,
ebfc3b49	264	bool excl)
1da177e4 LT	265	{
1da177e4 LT	266	struct super_block *sb = dir->i_sb;
ae78bf9c	267	struct inode *inode = NULL;
1da177e4	268	struct fat_slot_info sinfo;
95582b00	269	struct timespec64 ts;
1da177e4 LT	270	unsigned char msdos_name[MSDOS_NAME];
	271	int err, is_hid;
	272
e40b34c7	273	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	274
	275	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
	276	msdos_name, &MSDOS_SB(sb)->options);
	277	if (err)
	278	goto out;
	279	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
	280	/* Have to do it due to foo vs. .foo conflicts */
	281	if (!fat_scan(dir, msdos_name, &sinfo)) {
	282	brelse(sinfo.bh);
	283	err = -EINVAL;
	284	goto out;
	285	}
	286
02027d42	287	ts = current_time(dir);
f423420c	288	err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
1da177e4 LT	289	if (err)
	290	goto out;
	291	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	292	brelse(sinfo.bh);
	293	if (IS_ERR(inode)) {
	294	err = PTR_ERR(inode);
	295	goto out;
	296	}
	297	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
	298	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
	299
	300	d_instantiate(dentry, inode);
	301	out:
e40b34c7	302	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c CM	303	if (!err)
ae78bf9c CM	304	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	305	return err;
	306	}
	307
	308	/***** Remove a directory */
	309	static int msdos_rmdir(struct inode dir, struct dentry dentry)
	310	{
8f593427	311	struct super_block *sb = dir->i_sb;
2b0143b5	312	struct inode *inode = d_inode(dentry);
1da177e4 LT	313	struct fat_slot_info sinfo;
	314	int err;
	315
e40b34c7	316	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	317	err = fat_dir_empty(inode);
	318	if (err)
	319	goto out;
	320	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	321	if (err)
	322	goto out;
	323
	324	err = fat_remove_entries(dir, &sinfo); /* and releases bh */
	325	if (err)
	326	goto out;
9a53c3a7	327	drop_nlink(dir);
1da177e4	328
ce71ec36	329	clear_nlink(inode);
02027d42	330	inode->i_ctime = current_time(inode);
1da177e4 LT	331	fat_detach(inode);
1da177e4 LT	332	out:
e40b34c7	333	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	334	if (!err)
8f593427	335	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	336
	337	return err;
	338	}
	339
	340	/***** Make a directory */
18bb1db3	341	static int msdos_mkdir(struct inode dir, struct dentry dentry, umode_t mode)
1da177e4 LT	342	{
	343	struct super_block *sb = dir->i_sb;
	344	struct fat_slot_info sinfo;
	345	struct inode *inode;
	346	unsigned char msdos_name[MSDOS_NAME];
95582b00	347	struct timespec64 ts;
1da177e4 LT	348	int err, is_hid, cluster;
1da177e4 LT	349
e40b34c7	350	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	351
	352	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
	353	msdos_name, &MSDOS_SB(sb)->options);
	354	if (err)
	355	goto out;
	356	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
	357	/* foo vs .foo situation */
	358	if (!fat_scan(dir, msdos_name, &sinfo)) {
	359	brelse(sinfo.bh);
	360	err = -EINVAL;
	361	goto out;
	362	}
	363
02027d42	364	ts = current_time(dir);
f423420c	365	cluster = fat_alloc_new_dir(dir, &ts);
1da177e4 LT	366	if (cluster < 0) {
	367	err = cluster;
	368	goto out;
	369	}
f423420c	370	err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
1da177e4 LT	371	if (err)
1da177e4 LT	372	goto out_free;
d8c76e6f	373	inc_nlink(dir);
1da177e4 LT	374
	375	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	376	brelse(sinfo.bh);
	377	if (IS_ERR(inode)) {
	378	err = PTR_ERR(inode);
	379	/* the directory was completed, just return a error */
	380	goto out;
	381	}
bfe86848	382	set_nlink(inode, 2);
1da177e4 LT	383	inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
	384	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
	385
	386	d_instantiate(dentry, inode);
	387
e40b34c7	388	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	389	fat_flush_inodes(sb, dir, inode);
1da177e4 LT	390	return 0;
	391
	392	out_free:
	393	fat_free_clusters(dir, cluster);
	394	out:
e40b34c7	395	mutex_unlock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	396	return err;
	397	}
	398
	399	/***** Unlink a file */
	400	static int msdos_unlink(struct inode dir, struct dentry dentry)
	401	{
2b0143b5	402	struct inode *inode = d_inode(dentry);
85cb9bf5	403	struct super_block *sb = inode->i_sb;
1da177e4 LT	404	struct fat_slot_info sinfo;
	405	int err;
	406
e40b34c7	407	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	408	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	409	if (err)
	410	goto out;
	411
	412	err = fat_remove_entries(dir, &sinfo); /* and releases bh */
	413	if (err)
	414	goto out;
ce71ec36	415	clear_nlink(inode);
02027d42	416	inode->i_ctime = current_time(inode);
1da177e4 LT	417	fat_detach(inode);
1da177e4 LT	418	out:
e40b34c7	419	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	420	if (!err)
8f593427	421	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	422
	423	return err;
	424	}
	425
	426	static int do_msdos_rename(struct inode old_dir, unsigned char old_name,
	427	struct dentry *old_dentry,
	428	struct inode new_dir, unsigned char new_name,
	429	struct dentry *new_dentry, int is_hid)
	430	{
	431	struct buffer_head *dotdot_bh;
	432	struct msdos_dir_entry *dotdot_de;
1da177e4 LT	433	struct inode old_inode, new_inode;
1da177e4 LT	434	struct fat_slot_info old_sinfo, sinfo;
95582b00	435	struct timespec64 ts;
7669e8fb	436	loff_t new_i_pos;
1da177e4 LT	437	int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
	438
	439	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
2b0143b5 DH	440	old_inode = d_inode(old_dentry);
2b0143b5 DH	441	new_inode = d_inode(new_dentry);
1da177e4 LT	442
	443	err = fat_scan(old_dir, old_name, &old_sinfo);
	444	if (err) {
	445	err = -EIO;
	446	goto out;
	447	}
	448
	449	is_dir = S_ISDIR(old_inode->i_mode);
	450	update_dotdot = (is_dir && old_dir != new_dir);
	451	if (update_dotdot) {
7669e8fb	452	if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
1da177e4 LT	453	err = -EIO;
	454	goto out;
	455	}
	456	}
	457
	458	old_attrs = MSDOS_I(old_inode)->i_attrs;
	459	err = fat_scan(new_dir, new_name, &sinfo);
	460	if (!err) {
	461	if (!new_inode) {
	462	/* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
	463	if (sinfo.de != old_sinfo.de) {
	464	err = -EINVAL;
	465	goto out;
	466	}
	467	if (is_hid)
	468	MSDOS_I(old_inode)->i_attrs \|= ATTR_HIDDEN;
	469	else
	470	MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
	471	if (IS_DIRSYNC(old_dir)) {
	472	err = fat_sync_inode(old_inode);
	473	if (err) {
	474	MSDOS_I(old_inode)->i_attrs = old_attrs;
	475	goto out;
	476	}
	477	} else
	478	mark_inode_dirty(old_inode);
	479
2489dbab	480	inode_inc_iversion(old_dir);
02027d42	481	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
1da177e4 LT	482	if (IS_DIRSYNC(old_dir))
	483	(void)fat_sync_inode(old_dir);
	484	else
	485	mark_inode_dirty(old_dir);
	486	goto out;
	487	}
	488	}
	489
02027d42	490	ts = current_time(old_inode);
1da177e4 LT	491	if (new_inode) {
	492	if (err)
	493	goto out;
1da177e4 LT	494	if (is_dir) {
	495	err = fat_dir_empty(new_inode);
	496	if (err)
	497	goto out;
	498	}
9131dd42	499	new_i_pos = MSDOS_I(new_inode)->i_pos;
1da177e4 LT	500	fat_detach(new_inode);
	501	} else {
	502	err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
f423420c	503	&ts, &sinfo);
1da177e4 LT	504	if (err)
1da177e4 LT	505	goto out;
9131dd42	506	new_i_pos = sinfo.i_pos;
1da177e4	507	}
2489dbab	508	inode_inc_iversion(new_dir);
1da177e4 LT	509
1da177e4 LT	510	fat_detach(old_inode);
9131dd42	511	fat_attach(old_inode, new_i_pos);
1da177e4 LT	512	if (is_hid)
	513	MSDOS_I(old_inode)->i_attrs \|= ATTR_HIDDEN;
	514	else
	515	MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
	516	if (IS_DIRSYNC(new_dir)) {
	517	err = fat_sync_inode(old_inode);
	518	if (err)
	519	goto error_inode;
	520	} else
	521	mark_inode_dirty(old_inode);
	522
	523	if (update_dotdot) {
a943ed71	524	fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
b522412a	525	mark_buffer_dirty_inode(dotdot_bh, old_inode);
1da177e4 LT	526	if (IS_DIRSYNC(new_dir)) {
	527	err = sync_dirty_buffer(dotdot_bh);
	528	if (err)
	529	goto error_dotdot;
	530	}
9a53c3a7	531	drop_nlink(old_dir);
1da177e4	532	if (!new_inode)
d8c76e6f	533	inc_nlink(new_dir);
1da177e4 LT	534	}
	535
	536	err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
	537	old_sinfo.bh = NULL;
	538	if (err)
	539	goto error_dotdot;
2489dbab	540	inode_inc_iversion(old_dir);
1da177e4 LT	541	old_dir->i_ctime = old_dir->i_mtime = ts;
	542	if (IS_DIRSYNC(old_dir))
	543	(void)fat_sync_inode(old_dir);
	544	else
	545	mark_inode_dirty(old_dir);
	546
	547	if (new_inode) {
9a53c3a7	548	drop_nlink(new_inode);
1da177e4	549	if (is_dir)
9a53c3a7	550	drop_nlink(new_inode);
1da177e4 LT	551	new_inode->i_ctime = ts;
	552	}
	553	out:
	554	brelse(sinfo.bh);
	555	brelse(dotdot_bh);
	556	brelse(old_sinfo.bh);
	557	return err;
	558
	559	error_dotdot:
	560	/* data cluster is shared, serious corruption */
	561	corrupt = 1;
	562
	563	if (update_dotdot) {
a943ed71	564	fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
b522412a	565	mark_buffer_dirty_inode(dotdot_bh, old_inode);
1da177e4 LT	566	corrupt \|= sync_dirty_buffer(dotdot_bh);
	567	}
	568	error_inode:
	569	fat_detach(old_inode);
	570	fat_attach(old_inode, old_sinfo.i_pos);
	571	MSDOS_I(old_inode)->i_attrs = old_attrs;
	572	if (new_inode) {
9131dd42	573	fat_attach(new_inode, new_i_pos);
1da177e4 LT	574	if (corrupt)
	575	corrupt \|= fat_sync_inode(new_inode);
	576	} else {
	577	/*
	578	* If new entry was not sharing the data cluster, it
	579	* shouldn't be serious corruption.
	580	*/
	581	int err2 = fat_remove_entries(new_dir, &sinfo);
	582	if (corrupt)
	583	corrupt \|= err2;
	584	sinfo.bh = NULL;
	585	}
	586	if (corrupt < 0) {
85c78591	587	fat_fs_error(new_dir->i_sb,
1da177e4	588	"%s: Filesystem corrupted (i_pos %lld)",
8e24eea7	589	__func__, sinfo.i_pos);
1da177e4 LT	590	}
	591	goto out;
	592	}
	593
	594	/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
	595	static int msdos_rename(struct inode old_dir, struct dentry old_dentry,
f03b8ad8 MS	596	struct inode new_dir, struct dentry new_dentry,
f03b8ad8 MS	597	unsigned int flags)
1da177e4	598	{
8f593427	599	struct super_block *sb = old_dir->i_sb;
1da177e4 LT	600	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
	601	int err, is_hid;
	602
f03b8ad8 MS	603	if (flags & ~RENAME_NOREPLACE)
	604	return -EINVAL;
	605
e40b34c7	606	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	607
	608	err = msdos_format_name(old_dentry->d_name.name,
	609	old_dentry->d_name.len, old_msdos_name,
	610	&MSDOS_SB(old_dir->i_sb)->options);
	611	if (err)
	612	goto out;
	613	err = msdos_format_name(new_dentry->d_name.name,
	614	new_dentry->d_name.len, new_msdos_name,
	615	&MSDOS_SB(new_dir->i_sb)->options);
	616	if (err)
	617	goto out;
	618
	619	is_hid =
	620	(new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
	621
	622	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
	623	new_dir, new_msdos_name, new_dentry, is_hid);
	624	out:
e40b34c7	625	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	626	if (!err)
8f593427	627	err = fat_flush_inodes(sb, old_dir, new_dir);
1da177e4 LT	628	return err;
	629	}
	630
92e1d5be	631	static const struct inode_operations msdos_dir_inode_operations = {
1da177e4 LT	632	.create = msdos_create,
	633	.lookup = msdos_lookup,
	634	.unlink = msdos_unlink,
	635	.mkdir = msdos_mkdir,
	636	.rmdir = msdos_rmdir,
	637	.rename = msdos_rename,
1278fdd3	638	.setattr = fat_setattr,
da63fc7c	639	.getattr = fat_getattr,
1da177e4 LT	640	};
1da177e4 LT	641
3d23985d	642	static void setup(struct super_block *sb)
1da177e4	643	{
384f5c96	644	MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
3d23985d	645	sb->s_d_op = &msdos_dentry_operations;
1751e8a6	646	sb->s_flags \|= SB_NOATIME;
3d23985d AV	647	}
	648
	649	static int msdos_fill_super(struct super_block sb, void data, int silent)
	650	{
384f5c96	651	return fat_fill_super(sb, data, silent, 0, setup);
1da177e4 LT	652	}
1da177e4 LT	653
152a0836	654	static struct dentry msdos_mount(struct file_system_type fs_type,
454e2398	655	int flags, const char *dev_name,
152a0836	656	void *data)
1da177e4	657	{
152a0836	658	return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
1da177e4 LT	659	}
	660
	661	static struct file_system_type msdos_fs_type = {
	662	.owner = THIS_MODULE,
	663	.name = "msdos",
152a0836	664	.mount = msdos_mount,
1da177e4 LT	665	.kill_sb = kill_block_super,
	666	.fs_flags = FS_REQUIRES_DEV,
	667	};
7f78e035	668	MODULE_ALIAS_FS("msdos");
1da177e4 LT	669
	670	static int __init init_msdos_fs(void)
	671	{
	672	return register_filesystem(&msdos_fs_type);
	673	}
	674
	675	static void __exit exit_msdos_fs(void)
	676	{
	677	unregister_filesystem(&msdos_fs_type);
	678	}
	679
	680	MODULE_LICENSE("GPL");
	681	MODULE_AUTHOR("Werner Almesberger");
	682	MODULE_DESCRIPTION("MS-DOS filesystem support");
	683
	684	module_init(init_msdos_fs)
	685	module_exit(exit_msdos_fs)