[linux-2.6-block.git] / fs / fat / namei_msdos.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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/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;

	fat_truncate_time(dir, ts, S_CTIME|S_MTIME);
	if (IS_DIRSYNC(dir))
		(void)fat_sync_inode(dir);
	else
		mark_inode_dirty(dir);

	return 0;
}

/***** Create a file */
static int msdos_create(struct mnt_idmap *idmap, 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;
	}
	fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME);
	/* 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);
	fat_truncate_time(inode, NULL, S_CTIME);
	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 mnt_idmap *idmap, 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);
	fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME);
	/* 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);
	fat_truncate_time(inode, NULL, S_CTIME);
	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);
			fat_truncate_time(old_dir, NULL, S_CTIME|S_MTIME);
			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);
	fat_truncate_time(old_dir, &ts, S_CTIME|S_MTIME);
	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);
		fat_truncate_time(new_inode, &ts, S_CTIME);
	}
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 mnt_idmap *idmap,
			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,
	.update_time	= fat_update_time,
};

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 | FS_ALLOW_IDMAP,
};
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
09c434b8	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* linux/fs/msdos/namei.c
	4	*
	5	* Written 1992,1993 by Werner Almesberger
	6	* Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
	7	* Rewritten for constant inumbers 1999 by Al Viro
	8	*/
	9
	10	#include <linux/module.h>
2489dbab	11	#include <linux/iversion.h>
9e975dae	12	#include "fat.h"
1da177e4	13
1da177e4 LT	14	/* Characters that are undesirable in an MS-DOS file name */
1da177e4 LT	15	static unsigned char bad_chars[] = "*?<>\|\"";
7557bc66	16	static unsigned char bad_if_strict[] = "+=,; ";
1da177e4 LT	17
	18	/***** Formats an MS-DOS file name. Rejects invalid names. */
	19	static int msdos_format_name(const unsigned char *name, int len,
	20	unsigned char res, struct fat_mount_options opts)
	21	/*
	22	* name is the proposed name, len is its length, res is
	23	* the resulting name, opts->name_check is either (r)elaxed,
	24	* (n)ormal or (s)trict, opts->dotsOK allows dots at the
	25	* beginning of name (for hidden files)
	26	*/
	27	{
	28	unsigned char *walk;
1da177e4 LT	29	unsigned char c;
	30	int space;
	31
	32	if (name[0] == '.') { /* dotfile because . and .. already done */
	33	if (opts->dotsOK) {
	34	/* Get rid of dot - test for it elsewhere */
	35	name++;
	36	len--;
7557bc66	37	} else
1da177e4 LT	38	return -EINVAL;
	39	}
	40	/*
7557bc66	41	* disallow names that _really_ start with a dot
1da177e4	42	*/
7557bc66	43	space = 1;
1da177e4 LT	44	c = 0;
	45	for (walk = res; len && walk - res < 8; walk++) {
	46	c = *name++;
	47	len--;
	48	if (opts->name_check != 'r' && strchr(bad_chars, c))
	49	return -EINVAL;
7557bc66	50	if (opts->name_check == 's' && strchr(bad_if_strict, c))
1da177e4 LT	51	return -EINVAL;
	52	if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
	53	return -EINVAL;
	54	if (c < ' ' \|\| c == ':' \|\| c == '\\')
	55	return -EINVAL;
	56	/*
	57	* 0xE5 is legal as a first character, but we must substitute
	58	* 0x05 because 0xE5 marks deleted files. Yes, DOS really
	59	* does this.
	60	* It seems that Microsoft hacked DOS to support non-US
	61	* characters after the 0xE5 character was already in use to
	62	* mark deleted files.
	63	*/
	64	if ((res == walk) && (c == 0xE5))
	65	c = 0x05;
	66	if (c == '.')
	67	break;
	68	space = (c == ' ');
	69	*walk = (!opts->nocase && c >= 'a' && c <= 'z') ? c - 32 : c;
	70	}
	71	if (space)
	72	return -EINVAL;
	73	if (opts->name_check == 's' && len && c != '.') {
	74	c = *name++;
	75	len--;
	76	if (c != '.')
	77	return -EINVAL;
	78	}
	79	while (c != '.' && len--)
	80	c = *name++;
	81	if (c == '.') {
	82	while (walk - res < 8)
	83	*walk++ = ' ';
	84	while (len > 0 && walk - res < MSDOS_NAME) {
	85	c = *name++;
	86	len--;
	87	if (opts->name_check != 'r' && strchr(bad_chars, c))
	88	return -EINVAL;
	89	if (opts->name_check == 's' &&
7557bc66	90	strchr(bad_if_strict, c))
1da177e4 LT	91	return -EINVAL;
	92	if (c < ' ' \|\| c == ':' \|\| c == '\\')
	93	return -EINVAL;
	94	if (c == '.') {
	95	if (opts->name_check == 's')
	96	return -EINVAL;
	97	break;
	98	}
	99	if (c >= 'A' && c <= 'Z' && opts->name_check == 's')
	100	return -EINVAL;
	101	space = c == ' ';
	102	if (!opts->nocase && c >= 'a' && c <= 'z')
	103	*walk++ = c - 32;
	104	else
	105	*walk++ = c;
	106	}
	107	if (space)
	108	return -EINVAL;
	109	if (opts->name_check == 's' && len)
	110	return -EINVAL;
	111	}
	112	while (walk - res < MSDOS_NAME)
	113	*walk++ = ' ';
094e320d	114
1da177e4 LT	115	return 0;
	116	}
	117
	118	/***** Locates a directory entry. Uses unformatted name. */
	119	static int msdos_find(struct inode dir, const unsigned char name, int len,
	120	struct fat_slot_info *sinfo)
	121	{
	122	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
	123	unsigned char msdos_name[MSDOS_NAME];
	124	int err;
	125
	126	err = msdos_format_name(name, len, msdos_name, &sbi->options);
	127	if (err)
	128	return -ENOENT;
	129
	130	err = fat_scan(dir, msdos_name, sinfo);
	131	if (!err && sbi->options.dotsOK) {
	132	if (name[0] == '.') {
	133	if (!(sinfo->de->attr & ATTR_HIDDEN))
	134	err = -ENOENT;
	135	} else {
	136	if (sinfo->de->attr & ATTR_HIDDEN)
	137	err = -ENOENT;
	138	}
	139	if (err)
	140	brelse(sinfo->bh);
	141	}
	142	return err;
	143	}
	144
	145	/*
	146	* Compute the hash for the msdos name corresponding to the dentry.
	147	* Note: if the name is invalid, we leave the hash code unchanged so
	148	* that the existing dentry can be used. The msdos fs routines will
	149	* return ENOENT or EINVAL as appropriate.
	150	*/
da53be12	151	static int msdos_hash(const struct dentry dentry, struct qstr qstr)
1da177e4 LT	152	{
	153	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
	154	unsigned char msdos_name[MSDOS_NAME];
	155	int error;
	156
	157	error = msdos_format_name(qstr->name, qstr->len, msdos_name, options);
	158	if (!error)
8387ff25	159	qstr->hash = full_name_hash(dentry, msdos_name, MSDOS_NAME);
1da177e4 LT	160	return 0;
	161	}
	162
	163	/*
	164	* Compare two msdos names. If either of the names are invalid,
	165	* we fall back to doing the standard name comparison.
	166	*/
6fa67e70	167	static int msdos_cmp(const struct dentry *dentry,
621e155a	168	unsigned int len, const char str, const struct qstr name)
1da177e4	169	{
d3fe1985	170	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
1da177e4 LT	171	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
	172	int error;
	173
621e155a	174	error = msdos_format_name(name->name, name->len, a_msdos_name, options);
1da177e4 LT	175	if (error)
1da177e4 LT	176	goto old_compare;
621e155a	177	error = msdos_format_name(str, len, b_msdos_name, options);
1da177e4 LT	178	if (error)
	179	goto old_compare;
	180	error = memcmp(a_msdos_name, b_msdos_name, MSDOS_NAME);
	181	out:
	182	return error;
	183
	184	old_compare:
	185	error = 1;
621e155a NP	186	if (name->len == len)
621e155a NP	187	error = memcmp(name->name, str, len);
1da177e4 LT	188	goto out;
	189	}
	190
ce6cdc47	191	static const struct dentry_operations msdos_dentry_operations = {
1da177e4 LT	192	.d_hash = msdos_hash,
	193	.d_compare = msdos_cmp,
	194	};
	195
	196	/*
	197	* AV. Wrappers for FAT sb operations. Is it wise?
	198	*/
	199
	200	/***** Get inode using directory and name */
	201	static struct dentry msdos_lookup(struct inode dir, struct dentry *dentry,
00cd8dd3	202	unsigned int flags)
1da177e4 LT	203	{
	204	struct super_block *sb = dir->i_sb;
	205	struct fat_slot_info sinfo;
45cfbe35 OH	206	struct inode *inode;
45cfbe35 OH	207	int err;
1da177e4	208
e40b34c7	209	mutex_lock(&MSDOS_SB(sb)->s_lock);
45cfbe35	210	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
a9049376 AV	211	switch (err) {
	212	case -ENOENT:
	213	inode = NULL;
	214	break;
	215	case 0:
	216	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	217	brelse(sinfo.bh);
	218	break;
	219	default:
	220	inode = ERR_PTR(err);
1da177e4	221	}
e40b34c7	222	mutex_unlock(&MSDOS_SB(sb)->s_lock);
3d23985d	223	return d_splice_alias(inode, dentry);
1da177e4 LT	224	}
	225
	226	/***** Creates a directory entry (name is already formatted). */
	227	static int msdos_add_entry(struct inode dir, const unsigned char name,
	228	int is_dir, int is_hid, int cluster,
f423420c	229	struct timespec64 ts, struct fat_slot_info sinfo)
1da177e4	230	{
b271e067	231	struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
1da177e4 LT	232	struct msdos_dir_entry de;
	233	__le16 time, date;
	234	int err;
	235
	236	memcpy(de.name, name, MSDOS_NAME);
	237	de.attr = is_dir ? ATTR_DIR : ATTR_ARCH;
	238	if (is_hid)
	239	de.attr \|= ATTR_HIDDEN;
	240	de.lcase = 0;
7decd1cb	241	fat_time_unix2fat(sbi, ts, &time, &date, NULL);
1da177e4 LT	242	de.cdate = de.adate = 0;
	243	de.ctime = 0;
	244	de.ctime_cs = 0;
	245	de.time = time;
	246	de.date = date;
a943ed71	247	fat_set_start(&de, cluster);
1da177e4 LT	248	de.size = 0;
	249
	250	err = fat_add_entries(dir, &de, 1, sinfo);
	251	if (err)
	252	return err;
	253
cd83f6b1	254	fat_truncate_time(dir, ts, S_CTIME\|S_MTIME);
1da177e4 LT	255	if (IS_DIRSYNC(dir))
	256	(void)fat_sync_inode(dir);
	257	else
	258	mark_inode_dirty(dir);
	259
	260	return 0;
	261	}
	262
	263	/***** Create a file */
6c960e68	264	static int msdos_create(struct mnt_idmap idmap, struct inode dir,
549c7297	265	struct dentry *dentry, umode_t mode, bool excl)
1da177e4 LT	266	{
1da177e4 LT	267	struct super_block *sb = dir->i_sb;
ae78bf9c	268	struct inode *inode = NULL;
1da177e4	269	struct fat_slot_info sinfo;
95582b00	270	struct timespec64 ts;
1da177e4 LT	271	unsigned char msdos_name[MSDOS_NAME];
	272	int err, is_hid;
	273
e40b34c7	274	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	275
	276	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
	277	msdos_name, &MSDOS_SB(sb)->options);
	278	if (err)
	279	goto out;
	280	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
	281	/* Have to do it due to foo vs. .foo conflicts */
	282	if (!fat_scan(dir, msdos_name, &sinfo)) {
	283	brelse(sinfo.bh);
	284	err = -EINVAL;
	285	goto out;
	286	}
	287
02027d42	288	ts = current_time(dir);
f423420c	289	err = msdos_add_entry(dir, msdos_name, 0, is_hid, 0, &ts, &sinfo);
1da177e4 LT	290	if (err)
	291	goto out;
	292	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	293	brelse(sinfo.bh);
	294	if (IS_ERR(inode)) {
	295	err = PTR_ERR(inode);
	296	goto out;
	297	}
cd83f6b1	298	fat_truncate_time(inode, &ts, S_ATIME\|S_CTIME\|S_MTIME);
1da177e4 LT	299	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
	300
	301	d_instantiate(dentry, inode);
	302	out:
e40b34c7	303	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c CM	304	if (!err)
ae78bf9c CM	305	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	306	return err;
	307	}
	308
	309	/***** Remove a directory */
	310	static int msdos_rmdir(struct inode dir, struct dentry dentry)
	311	{
8f593427	312	struct super_block *sb = dir->i_sb;
2b0143b5	313	struct inode *inode = d_inode(dentry);
1da177e4 LT	314	struct fat_slot_info sinfo;
	315	int err;
	316
e40b34c7	317	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	318	err = fat_dir_empty(inode);
	319	if (err)
	320	goto out;
	321	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	322	if (err)
	323	goto out;
	324
	325	err = fat_remove_entries(dir, &sinfo); /* and releases bh */
	326	if (err)
	327	goto out;
9a53c3a7	328	drop_nlink(dir);
1da177e4	329
ce71ec36	330	clear_nlink(inode);
cd83f6b1	331	fat_truncate_time(inode, NULL, S_CTIME);
1da177e4 LT	332	fat_detach(inode);
1da177e4 LT	333	out:
e40b34c7	334	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	335	if (!err)
8f593427	336	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	337
	338	return err;
	339	}
	340
	341	/***** Make a directory */
c54bd91e	342	static int msdos_mkdir(struct mnt_idmap idmap, struct inode dir,
549c7297	343	struct dentry *dentry, umode_t mode)
1da177e4 LT	344	{
	345	struct super_block *sb = dir->i_sb;
	346	struct fat_slot_info sinfo;
	347	struct inode *inode;
	348	unsigned char msdos_name[MSDOS_NAME];
95582b00	349	struct timespec64 ts;
1da177e4 LT	350	int err, is_hid, cluster;
1da177e4 LT	351
e40b34c7	352	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	353
	354	err = msdos_format_name(dentry->d_name.name, dentry->d_name.len,
	355	msdos_name, &MSDOS_SB(sb)->options);
	356	if (err)
	357	goto out;
	358	is_hid = (dentry->d_name.name[0] == '.') && (msdos_name[0] != '.');
	359	/* foo vs .foo situation */
	360	if (!fat_scan(dir, msdos_name, &sinfo)) {
	361	brelse(sinfo.bh);
	362	err = -EINVAL;
	363	goto out;
	364	}
	365
02027d42	366	ts = current_time(dir);
f423420c	367	cluster = fat_alloc_new_dir(dir, &ts);
1da177e4 LT	368	if (cluster < 0) {
	369	err = cluster;
	370	goto out;
	371	}
f423420c	372	err = msdos_add_entry(dir, msdos_name, 1, is_hid, cluster, &ts, &sinfo);
1da177e4 LT	373	if (err)
1da177e4 LT	374	goto out_free;
d8c76e6f	375	inc_nlink(dir);
1da177e4 LT	376
	377	inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
	378	brelse(sinfo.bh);
	379	if (IS_ERR(inode)) {
	380	err = PTR_ERR(inode);
	381	/* the directory was completed, just return a error */
	382	goto out;
	383	}
bfe86848	384	set_nlink(inode, 2);
cd83f6b1	385	fat_truncate_time(inode, &ts, S_ATIME\|S_CTIME\|S_MTIME);
1da177e4 LT	386	/* timestamp is already written, so mark_inode_dirty() is unneeded. */
	387
	388	d_instantiate(dentry, inode);
	389
e40b34c7	390	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	391	fat_flush_inodes(sb, dir, inode);
1da177e4 LT	392	return 0;
	393
	394	out_free:
	395	fat_free_clusters(dir, cluster);
	396	out:
e40b34c7	397	mutex_unlock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	398	return err;
	399	}
	400
	401	/***** Unlink a file */
	402	static int msdos_unlink(struct inode dir, struct dentry dentry)
	403	{
2b0143b5	404	struct inode *inode = d_inode(dentry);
85cb9bf5	405	struct super_block *sb = inode->i_sb;
1da177e4 LT	406	struct fat_slot_info sinfo;
	407	int err;
	408
e40b34c7	409	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	410	err = msdos_find(dir, dentry->d_name.name, dentry->d_name.len, &sinfo);
	411	if (err)
	412	goto out;
	413
	414	err = fat_remove_entries(dir, &sinfo); /* and releases bh */
	415	if (err)
	416	goto out;
ce71ec36	417	clear_nlink(inode);
cd83f6b1	418	fat_truncate_time(inode, NULL, S_CTIME);
1da177e4 LT	419	fat_detach(inode);
1da177e4 LT	420	out:
e40b34c7	421	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	422	if (!err)
8f593427	423	err = fat_flush_inodes(sb, dir, inode);
1da177e4 LT	424
	425	return err;
	426	}
	427
	428	static int do_msdos_rename(struct inode old_dir, unsigned char old_name,
	429	struct dentry *old_dentry,
	430	struct inode new_dir, unsigned char new_name,
	431	struct dentry *new_dentry, int is_hid)
	432	{
	433	struct buffer_head *dotdot_bh;
	434	struct msdos_dir_entry *dotdot_de;
1da177e4 LT	435	struct inode old_inode, new_inode;
1da177e4 LT	436	struct fat_slot_info old_sinfo, sinfo;
95582b00	437	struct timespec64 ts;
7669e8fb	438	loff_t new_i_pos;
1da177e4 LT	439	int err, old_attrs, is_dir, update_dotdot, corrupt = 0;
	440
	441	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
2b0143b5 DH	442	old_inode = d_inode(old_dentry);
2b0143b5 DH	443	new_inode = d_inode(new_dentry);
1da177e4 LT	444
	445	err = fat_scan(old_dir, old_name, &old_sinfo);
	446	if (err) {
	447	err = -EIO;
	448	goto out;
	449	}
	450
	451	is_dir = S_ISDIR(old_inode->i_mode);
	452	update_dotdot = (is_dir && old_dir != new_dir);
	453	if (update_dotdot) {
7669e8fb	454	if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) {
1da177e4 LT	455	err = -EIO;
	456	goto out;
	457	}
	458	}
	459
	460	old_attrs = MSDOS_I(old_inode)->i_attrs;
	461	err = fat_scan(new_dir, new_name, &sinfo);
	462	if (!err) {
	463	if (!new_inode) {
	464	/* "foo" -> ".foo" case. just change the ATTR_HIDDEN */
	465	if (sinfo.de != old_sinfo.de) {
	466	err = -EINVAL;
	467	goto out;
	468	}
	469	if (is_hid)
	470	MSDOS_I(old_inode)->i_attrs \|= ATTR_HIDDEN;
	471	else
	472	MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
	473	if (IS_DIRSYNC(old_dir)) {
	474	err = fat_sync_inode(old_inode);
	475	if (err) {
	476	MSDOS_I(old_inode)->i_attrs = old_attrs;
	477	goto out;
	478	}
	479	} else
	480	mark_inode_dirty(old_inode);
	481
2489dbab	482	inode_inc_iversion(old_dir);
cd83f6b1	483	fat_truncate_time(old_dir, NULL, S_CTIME\|S_MTIME);
1da177e4 LT	484	if (IS_DIRSYNC(old_dir))
	485	(void)fat_sync_inode(old_dir);
	486	else
	487	mark_inode_dirty(old_dir);
	488	goto out;
	489	}
	490	}
	491
02027d42	492	ts = current_time(old_inode);
1da177e4 LT	493	if (new_inode) {
	494	if (err)
	495	goto out;
1da177e4 LT	496	if (is_dir) {
	497	err = fat_dir_empty(new_inode);
	498	if (err)
	499	goto out;
	500	}
9131dd42	501	new_i_pos = MSDOS_I(new_inode)->i_pos;
1da177e4 LT	502	fat_detach(new_inode);
	503	} else {
	504	err = msdos_add_entry(new_dir, new_name, is_dir, is_hid, 0,
f423420c	505	&ts, &sinfo);
1da177e4 LT	506	if (err)
1da177e4 LT	507	goto out;
9131dd42	508	new_i_pos = sinfo.i_pos;
1da177e4	509	}
2489dbab	510	inode_inc_iversion(new_dir);
1da177e4 LT	511
1da177e4 LT	512	fat_detach(old_inode);
9131dd42	513	fat_attach(old_inode, new_i_pos);
1da177e4 LT	514	if (is_hid)
	515	MSDOS_I(old_inode)->i_attrs \|= ATTR_HIDDEN;
	516	else
	517	MSDOS_I(old_inode)->i_attrs &= ~ATTR_HIDDEN;
	518	if (IS_DIRSYNC(new_dir)) {
	519	err = fat_sync_inode(old_inode);
	520	if (err)
	521	goto error_inode;
	522	} else
	523	mark_inode_dirty(old_inode);
	524
	525	if (update_dotdot) {
a943ed71	526	fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart);
b522412a	527	mark_buffer_dirty_inode(dotdot_bh, old_inode);
1da177e4 LT	528	if (IS_DIRSYNC(new_dir)) {
	529	err = sync_dirty_buffer(dotdot_bh);
	530	if (err)
	531	goto error_dotdot;
	532	}
9a53c3a7	533	drop_nlink(old_dir);
1da177e4	534	if (!new_inode)
d8c76e6f	535	inc_nlink(new_dir);
1da177e4 LT	536	}
	537
	538	err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */
	539	old_sinfo.bh = NULL;
	540	if (err)
	541	goto error_dotdot;
2489dbab	542	inode_inc_iversion(old_dir);
cd83f6b1	543	fat_truncate_time(old_dir, &ts, S_CTIME\|S_MTIME);
1da177e4 LT	544	if (IS_DIRSYNC(old_dir))
	545	(void)fat_sync_inode(old_dir);
	546	else
	547	mark_inode_dirty(old_dir);
	548
	549	if (new_inode) {
9a53c3a7	550	drop_nlink(new_inode);
1da177e4	551	if (is_dir)
9a53c3a7	552	drop_nlink(new_inode);
cd83f6b1	553	fat_truncate_time(new_inode, &ts, S_CTIME);
1da177e4 LT	554	}
	555	out:
	556	brelse(sinfo.bh);
	557	brelse(dotdot_bh);
	558	brelse(old_sinfo.bh);
	559	return err;
	560
	561	error_dotdot:
	562	/* data cluster is shared, serious corruption */
	563	corrupt = 1;
	564
	565	if (update_dotdot) {
a943ed71	566	fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart);
b522412a	567	mark_buffer_dirty_inode(dotdot_bh, old_inode);
1da177e4 LT	568	corrupt \|= sync_dirty_buffer(dotdot_bh);
	569	}
	570	error_inode:
	571	fat_detach(old_inode);
	572	fat_attach(old_inode, old_sinfo.i_pos);
	573	MSDOS_I(old_inode)->i_attrs = old_attrs;
	574	if (new_inode) {
9131dd42	575	fat_attach(new_inode, new_i_pos);
1da177e4 LT	576	if (corrupt)
	577	corrupt \|= fat_sync_inode(new_inode);
	578	} else {
	579	/*
	580	* If new entry was not sharing the data cluster, it
	581	* shouldn't be serious corruption.
	582	*/
	583	int err2 = fat_remove_entries(new_dir, &sinfo);
	584	if (corrupt)
	585	corrupt \|= err2;
	586	sinfo.bh = NULL;
	587	}
	588	if (corrupt < 0) {
85c78591	589	fat_fs_error(new_dir->i_sb,
1da177e4	590	"%s: Filesystem corrupted (i_pos %lld)",
8e24eea7	591	__func__, sinfo.i_pos);
1da177e4 LT	592	}
	593	goto out;
	594	}
	595
	596	/***** Rename, a wrapper for rename_same_dir & rename_diff_dir */
e18275ae	597	static int msdos_rename(struct mnt_idmap *idmap,
549c7297	598	struct inode old_dir, struct dentry old_dentry,
f03b8ad8 MS	599	struct inode new_dir, struct dentry new_dentry,
f03b8ad8 MS	600	unsigned int flags)
1da177e4	601	{
8f593427	602	struct super_block *sb = old_dir->i_sb;
1da177e4 LT	603	unsigned char old_msdos_name[MSDOS_NAME], new_msdos_name[MSDOS_NAME];
	604	int err, is_hid;
	605
f03b8ad8 MS	606	if (flags & ~RENAME_NOREPLACE)
	607	return -EINVAL;
	608
e40b34c7	609	mutex_lock(&MSDOS_SB(sb)->s_lock);
1da177e4 LT	610
	611	err = msdos_format_name(old_dentry->d_name.name,
	612	old_dentry->d_name.len, old_msdos_name,
	613	&MSDOS_SB(old_dir->i_sb)->options);
	614	if (err)
	615	goto out;
	616	err = msdos_format_name(new_dentry->d_name.name,
	617	new_dentry->d_name.len, new_msdos_name,
	618	&MSDOS_SB(new_dir->i_sb)->options);
	619	if (err)
	620	goto out;
	621
	622	is_hid =
	623	(new_dentry->d_name.name[0] == '.') && (new_msdos_name[0] != '.');
	624
	625	err = do_msdos_rename(old_dir, old_msdos_name, old_dentry,
	626	new_dir, new_msdos_name, new_dentry, is_hid);
	627	out:
e40b34c7	628	mutex_unlock(&MSDOS_SB(sb)->s_lock);
ae78bf9c	629	if (!err)
8f593427	630	err = fat_flush_inodes(sb, old_dir, new_dir);
1da177e4 LT	631	return err;
	632	}
	633
92e1d5be	634	static const struct inode_operations msdos_dir_inode_operations = {
1da177e4 LT	635	.create = msdos_create,
	636	.lookup = msdos_lookup,
	637	.unlink = msdos_unlink,
	638	.mkdir = msdos_mkdir,
	639	.rmdir = msdos_rmdir,
	640	.rename = msdos_rename,
1278fdd3	641	.setattr = fat_setattr,
da63fc7c	642	.getattr = fat_getattr,
6bb885ec	643	.update_time = fat_update_time,
1da177e4 LT	644	};
1da177e4 LT	645
3d23985d	646	static void setup(struct super_block *sb)
1da177e4	647	{
384f5c96	648	MSDOS_SB(sb)->dir_ops = &msdos_dir_inode_operations;
3d23985d	649	sb->s_d_op = &msdos_dentry_operations;
1751e8a6	650	sb->s_flags \|= SB_NOATIME;
3d23985d AV	651	}
	652
	653	static int msdos_fill_super(struct super_block sb, void data, int silent)
	654	{
384f5c96	655	return fat_fill_super(sb, data, silent, 0, setup);
1da177e4 LT	656	}
1da177e4 LT	657
152a0836	658	static struct dentry msdos_mount(struct file_system_type fs_type,
454e2398	659	int flags, const char *dev_name,
152a0836	660	void *data)
1da177e4	661	{
152a0836	662	return mount_bdev(fs_type, flags, dev_name, data, msdos_fill_super);
1da177e4 LT	663	}
	664
	665	static struct file_system_type msdos_fs_type = {
	666	.owner = THIS_MODULE,
	667	.name = "msdos",
152a0836	668	.mount = msdos_mount,
1da177e4	669	.kill_sb = kill_block_super,
4b789936	670	.fs_flags = FS_REQUIRES_DEV \| FS_ALLOW_IDMAP,
1da177e4	671	};
7f78e035	672	MODULE_ALIAS_FS("msdos");
1da177e4 LT	673
	674	static int __init init_msdos_fs(void)
	675	{
	676	return register_filesystem(&msdos_fs_type);
	677	}
	678
	679	static void __exit exit_msdos_fs(void)
	680	{
	681	unregister_filesystem(&msdos_fs_type);
	682	}
	683
	684	MODULE_LICENSE("GPL");
	685	MODULE_AUTHOR("Werner Almesberger");
	686	MODULE_DESCRIPTION("MS-DOS filesystem support");
	687
	688	module_init(init_msdos_fs)
	689	module_exit(exit_msdos_fs)