Beispiel #1
0
static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
                        struct inode * new_dir,	struct dentry * new_dentry )
{
    struct inode * old_inode = old_dentry->d_inode;
    struct inode * new_inode = new_dentry->d_inode;
    struct page * dir_page = NULL;
    struct ext2_dir_entry_2 * dir_de = NULL;
    struct page * old_page;
    struct ext2_dir_entry_2 * old_de;
    int err = -ENOENT;

    dquot_initialize(old_dir);
    dquot_initialize(new_dir);

    old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
    if (!old_de)
        goto out;

    if (S_ISDIR(old_inode->i_mode)) {
        err = -EIO;
        dir_de = ext2_dotdot(old_inode, &dir_page);
        if (!dir_de)
            goto out_old;
    }

    if (new_inode) {
        struct page *new_page;
        struct ext2_dir_entry_2 *new_de;

        err = -ENOTEMPTY;
        if (dir_de && !ext2_empty_dir (new_inode))
            goto out_dir;

        err = -ENOENT;
        new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
        if (!new_de)
            goto out_dir;
        ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
        new_inode->i_ctime = CURRENT_TIME_SEC;
        if (dir_de)
            drop_nlink(new_inode);
        inode_dec_link_count(new_inode);
    } else {
        err = ext2_add_link(new_dentry, old_inode);
        if (err)
            goto out_dir;
        if (dir_de)
            inode_inc_link_count(new_dir);
    }

    /*
     * Like most other Unix systems, set the ctime for inodes on a
     * rename.
     */
    old_inode->i_ctime = CURRENT_TIME_SEC;
    mark_inode_dirty(old_inode);

    ext2_delete_entry (old_de, old_page);

    if (dir_de) {
        if (old_dir != new_dir)
            ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
        else {
            kunmap(dir_page);
            page_cache_release(dir_page);
        }
        inode_dec_link_count(old_dir);
    }
    return 0;


out_dir:
    if (dir_de) {
        kunmap(dir_page);
        page_cache_release(dir_page);
    }
out_old:
    kunmap(old_page);
    page_cache_release(old_page);
out:
    return err;
}
Beispiel #2
0
static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	struct inode * new_dir,	struct dentry * new_dentry )
{
	struct inode * old_inode = old_dentry->d_inode;
	struct inode * new_inode = new_dentry->d_inode;
	struct page * dir_page = NULL;
	struct ext2_dir_entry_2 * dir_de = NULL;
	struct page * old_page;
	struct ext2_dir_entry_2 * old_de;
	int err = -ENOENT;

	old_de = ext2_find_entry (old_dir, old_dentry, &old_page);
	if (!old_de)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = ext2_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page *new_page;
		struct ext2_dir_entry_2 *new_de;

		err = -ENOTEMPTY;
		if (dir_de && !ext2_empty_dir (new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = ext2_find_entry (new_dir, new_dentry, &new_page);
		if (!new_de)
			goto out_dir;
		ext2_inc_count(old_inode);
		ext2_set_link(new_dir, new_de, new_page, old_inode);
		new_inode->i_ctime = CURRENT_TIME_SEC;
		if (dir_de)
			new_inode->i_nlink--;
		ext2_dec_count(new_inode);
	} else {
		if (dir_de) {
			err = -EMLINK;
			if (new_dir->i_nlink >= EXT2_LINK_MAX)
				goto out_dir;
		}
		ext2_inc_count(old_inode);
		err = ext2_add_link(new_dentry, old_inode);
		if (err) {
			ext2_dec_count(old_inode);
			goto out_dir;
		}
		if (dir_de)
			ext2_inc_count(new_dir);
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
	 * ext2_dec_count() will mark the inode dirty.
	 */
	old_inode->i_ctime = CURRENT_TIME_SEC;

	ext2_delete_entry (old_de, old_page);
	ext2_dec_count(old_inode);

	if (dir_de) {
		ext2_set_link(old_inode, dir_de, dir_page, new_dir);
		ext2_dec_count(old_dir);
	}
	return 0;


out_dir:
	if (dir_de) {
		kunmap(dir_page);
		page_cache_release(dir_page);
	}
out_old:
	kunmap(old_page);
	page_cache_release(old_page);
out:
	return err;
}
Beispiel #3
0
static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
                        struct inode * new_dir,	struct dentry * new_dentry )
{
    struct inode * old_inode = old_dentry->d_inode;
    struct inode * new_inode = new_dentry->d_inode;

    // Removing the old dir from the backlinks of the inode
    int i, link_pos = -1;
    struct ext2_inode_info *ei;
    // Use the new one if it is there
    if(new_inode) ei = EXT2_I(new_inode);
    else ei = EXT2_I(old_inode);

    for(i=0; i < EXT2_N_LINKS; i++) {
        if (ei->i_backlinks[i] == old_dir->i_ino) {
            link_pos = i;
            break;
        }
    }

    // If we find the backlink, remove it and move the other
    // backlinks up a bit.
    if (link_pos != -1) {
        for(i=link_pos; i < (EXT2_N_LINKS - 1); i++) {
            ei->i_backlinks[i] = ei->i_backlinks[i+1];
        }
    }

    struct page * dir_page = NULL;
    struct ext2_dir_entry_2 * dir_de = NULL;
    struct page * old_page;
    struct ext2_dir_entry_2 * old_de;
    int err = -ENOENT;

    old_de = ext2_find_entry (old_dir, old_dentry, &old_page);
    if (!old_de)
        goto out;

    if (S_ISDIR(old_inode->i_mode)) {
        err = -EIO;
        dir_de = ext2_dotdot(old_inode, &dir_page);
        if (!dir_de)
            goto out_old;
    }

    if (new_inode) {
        struct page *new_page;
        struct ext2_dir_entry_2 *new_de;

        err = -ENOTEMPTY;
        if (dir_de && !ext2_empty_dir (new_inode))
            goto out_dir;

        err = -ENOENT;
        new_de = ext2_find_entry (new_dir, new_dentry, &new_page);
        if (!new_de)
            goto out_dir;
        inode_inc_link_count(old_inode);
        ext2_set_link(new_dir, new_de, new_page, old_inode);
        new_inode->i_ctime = CURRENT_TIME_SEC;
        if (dir_de)
            drop_nlink(new_inode);
        inode_dec_link_count(new_inode);
    } else {
        if (dir_de) {
            err = -EMLINK;
            if (new_dir->i_nlink >= EXT2_LINK_MAX)
                goto out_dir;
        }
        inode_inc_link_count(old_inode);
        err = ext2_add_link(new_dentry, old_inode);
        if (err) {
            inode_dec_link_count(old_inode);
            goto out_dir;
        }
        if (dir_de)
            inode_inc_link_count(new_dir);
    }

    /*
     * Like most other Unix systems, set the ctime for inodes on a
     * rename.
     * inode_dec_link_count() will mark the inode dirty.
     */
    old_inode->i_ctime = CURRENT_TIME_SEC;

    ext2_delete_entry (old_de, old_page);
    inode_dec_link_count(old_inode);

    if (dir_de) {
        ext2_set_link(old_inode, dir_de, dir_page, new_dir);
        inode_dec_link_count(old_dir);
    }
    return 0;


out_dir:
    if (dir_de) {
        kunmap(dir_page);
        page_cache_release(dir_page);
    }
out_old:
    kunmap(old_page);
    page_cache_release(old_page);
out:
    return err;
}
Beispiel #4
0
struct dentry *ext2_get_parent(struct dentry *child)
{
	struct qstr dotdot = {.name = "..", .len = 2};
	unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
	if (!ino)
		return ERR_PTR(-ENOENT);
	return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
} 

/*
 * By the time this is called, we already have created
 * the directory cache entry for the new file, but it
 * is so far negative - it has no inode.
 *
 * If the create succeeds, we fill in the inode information
 * with d_instantiate(). 
 */
static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
{
	struct inode *inode;

	dquot_initialize(dir);

	inode = ext2_new_inode(dir, mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &ext2_file_inode_operations;
	if (ext2_use_xip(inode->i_sb)) {
		inode->i_mapping->a_ops = &ext2_aops_xip;
		inode->i_fop = &ext2_xip_file_operations;
	} else if (test_opt(inode->i_sb, NOBH)) {
		inode->i_mapping->a_ops = &ext2_nobh_aops;
		inode->i_fop = &ext2_file_operations;
	} else {
		inode->i_mapping->a_ops = &ext2_aops;
		inode->i_fop = &ext2_file_operations;
	}
	mark_inode_dirty(inode);
	return ext2_add_nondir(dentry, inode);
}

static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
{
	struct inode * inode;
	int err;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	dquot_initialize(dir);

	inode = ext2_new_inode (dir, mode);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		init_special_inode(inode, inode->i_mode, rdev);
#ifdef CONFIG_EXT2_FS_XATTR
		inode->i_op = &ext2_special_inode_operations;
#endif
		mark_inode_dirty(inode);
		err = ext2_add_nondir(dentry, inode);
	}
	return err;
}

static int ext2_symlink (struct inode * dir, struct dentry * dentry,
	const char * symname)
{
	struct super_block * sb = dir->i_sb;
	int err = -ENAMETOOLONG;
	unsigned l = strlen(symname)+1;
	struct inode * inode;

	if (l > sb->s_blocksize)
		goto out;

	dquot_initialize(dir);

	inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out;

	if (l > sizeof (EXT2_I(inode)->i_data)) {
		/* slow symlink */
		inode->i_op = &ext2_symlink_inode_operations;
		if (test_opt(inode->i_sb, NOBH))
			inode->i_mapping->a_ops = &ext2_nobh_aops;
		else
			inode->i_mapping->a_ops = &ext2_aops;
		err = page_symlink(inode, symname, l);
		if (err)
			goto out_fail;
	} else {
		/* fast symlink */
		inode->i_op = &ext2_fast_symlink_inode_operations;
		memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
		inode->i_size = l-1;
	}
	mark_inode_dirty(inode);

	err = ext2_add_nondir(dentry, inode);
out:
	return err;

out_fail:
	inode_dec_link_count(inode);
	unlock_new_inode(inode);
	iput (inode);
	goto out;
}

static int ext2_link (struct dentry * old_dentry, struct inode * dir,
	struct dentry *dentry)
{
	struct inode *inode = old_dentry->d_inode;
	int err;

	if (inode->i_nlink >= EXT2_LINK_MAX)
		return -EMLINK;

	dquot_initialize(dir);

	inode->i_ctime = CURRENT_TIME_SEC;
	inode_inc_link_count(inode);
	ihold(inode);

	err = ext2_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	inode_dec_link_count(inode);
	iput(inode);
	return err;
}

static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
{
	struct inode * inode;
	int err = -EMLINK;

	if (dir->i_nlink >= EXT2_LINK_MAX)
		goto out;

	dquot_initialize(dir);

	inode_inc_link_count(dir);

	inode = ext2_new_inode (dir, S_IFDIR | mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_dir;

	inode->i_op = &ext2_dir_inode_operations;
	inode->i_fop = &ext2_dir_operations;
	if (test_opt(inode->i_sb, NOBH))
		inode->i_mapping->a_ops = &ext2_nobh_aops;
	else
		inode->i_mapping->a_ops = &ext2_aops;

	inode_inc_link_count(inode);

	err = ext2_make_empty(inode, dir);
	if (err)
		goto out_fail;

	err = ext2_add_link(dentry, inode);
	if (err)
		goto out_fail;

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
out:
	return err;

out_fail:
	inode_dec_link_count(inode);
	inode_dec_link_count(inode);
	unlock_new_inode(inode);
	iput(inode);
out_dir:
	inode_dec_link_count(dir);
	goto out;
}

static int ext2_unlink(struct inode * dir, struct dentry *dentry)
{
	struct inode * inode = dentry->d_inode;
	struct ext2_dir_entry_2 * de;
	struct page * page;
	int err = -ENOENT;

	dquot_initialize(dir);

	de = ext2_find_entry (dir, &dentry->d_name, &page);
	if (!de)
		goto out;

	err = ext2_delete_entry (de, page);
	if (err)
		goto out;

	inode->i_ctime = dir->i_ctime;
	inode_dec_link_count(inode);
	err = 0;
out:
	return err;
}

static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
{
	struct inode * inode = dentry->d_inode;
	int err = -ENOTEMPTY;

	if (ext2_empty_dir(inode)) {
		err = ext2_unlink(dir, dentry);
		if (!err) {
			inode->i_size = 0;
			inode_dec_link_count(inode);
			inode_dec_link_count(dir);
		}
	}
	return err;
}

static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	struct inode * new_dir,	struct dentry * new_dentry )
{
	struct inode * old_inode = old_dentry->d_inode;
	struct inode * new_inode = new_dentry->d_inode;
	struct page * dir_page = NULL;
	struct ext2_dir_entry_2 * dir_de = NULL;
	struct page * old_page;
	struct ext2_dir_entry_2 * old_de;
	int err = -ENOENT;

	dquot_initialize(old_dir);
	dquot_initialize(new_dir);

	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
	if (!old_de)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = ext2_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page *new_page;
		struct ext2_dir_entry_2 *new_de;

		err = -ENOTEMPTY;
		if (dir_de && !ext2_empty_dir (new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
		if (!new_de)
			goto out_dir;
		ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
		new_inode->i_ctime = CURRENT_TIME_SEC;
		if (dir_de)
			drop_nlink(new_inode);
		inode_dec_link_count(new_inode);
	} else {
		if (dir_de) {
			err = -EMLINK;
			if (new_dir->i_nlink >= EXT2_LINK_MAX)
				goto out_dir;
		}
		err = ext2_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
	 */
	old_inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(old_inode);

	ext2_delete_entry (old_de, old_page);

	if (dir_de) {
		if (old_dir != new_dir)
			ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
		else {
			kunmap(dir_page);
			page_cache_release(dir_page);
		}
		inode_dec_link_count(old_dir);
	}
	return 0;


out_dir:
	if (dir_de) {
		kunmap(dir_page);
		page_cache_release(dir_page);
	}
out_old:
	kunmap(old_page);
	page_cache_release(old_page);
out:
	return err;
}

const struct inode_operations ext2_dir_inode_operations = {
	.create		= ext2_create,
	.lookup		= ext2_lookup,
	.link		= ext2_link,
	.unlink		= ext2_unlink,
	.symlink	= ext2_symlink,
	.mkdir		= ext2_mkdir,
	.rmdir		= ext2_rmdir,
	.mknod		= ext2_mknod,
	.rename		= ext2_rename,
#ifdef CONFIG_EXT2_FS_XATTR
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ext2_listxattr,
	.removexattr	= generic_removexattr,
#endif
	.setattr	= ext2_setattr,
	.check_acl	= ext2_check_acl,
};

const struct inode_operations ext2_special_inode_operations = {
#ifdef CONFIG_EXT2_FS_XATTR
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ext2_listxattr,
	.removexattr	= generic_removexattr,
#endif
	.setattr	= ext2_setattr,
	.check_acl	= ext2_check_acl,
};
Beispiel #5
0
/*
 * ext3301: modified to encrypt/decrypt files moving to/from
 * 	an encrypted folder.
 * Rename still succeeds if an encrypt/decrypt operation fails.
 */
static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	struct inode * new_dir,	struct dentry * new_dentry )
{
	struct inode * old_inode = old_dentry->d_inode;
	struct inode * new_inode = new_dentry->d_inode;
	struct page * dir_page = NULL;
	struct ext2_dir_entry_2 * dir_de = NULL;
	struct page * old_page;
	struct ext2_dir_entry_2 * old_de;
	int err = -ENOENT;

	bool is_encryptable, src_encrypt, dest_encrypt;
	int i;
	struct file * fcrypt;
	ssize_t nchunk, nread, nwritten;
	loff_t fpos, fseekpos;
	unsigned int fsize, fremaining;
	char * buf, * strbuf1, * strbuf2, * path_src, * path_dest;
	size_t blocksize = INODE_BLKSIZE(old_inode);

	//

	dquot_initialize(old_dir);
	dquot_initialize(new_dir);

	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
	if (!old_de)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = ext2_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page *new_page;
		struct ext2_dir_entry_2 *new_de;

		err = -ENOTEMPTY;
		if (dir_de && !ext2_empty_dir (new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
		if (!new_de)
			goto out_dir;
		ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
		new_inode->i_ctime = CURRENT_TIME_SEC;
		if (dir_de)
			drop_nlink(new_inode);
		inode_dec_link_count(new_inode);
	} else {
		err = ext2_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	// allocate buffers
	strbuf1 = kmalloc((size_t)512, GFP_KERNEL);
	strbuf2 = kmalloc((size_t)512, GFP_KERNEL);
	buf = kmalloc(blocksize, GFP_KERNEL);
	if (!buf || !strbuf1 || !strbuf2)
		return -ENOMEM;

	// check if the source XOR destination lie under /encrypt,
	// 	and both entries are regular or immediate files
	is_encryptable = (I_ISIM(old_inode) || I_ISREG(old_inode));
	src_encrypt = ext3301_isencrypted(old_dentry);
	dest_encrypt = ext3301_isencrypted(new_dentry);
	path_src  = ext3301_getpath(old_dentry, strbuf1, blocksize);
	path_dest = ext3301_getpath(new_dentry, strbuf2, blocksize);

	// decide whether to encrypt
	dbg(KERN_DEBUG "rename (%s --> %s)\n", path_src, path_dest);
	if (is_encryptable) {
		dbg_cr(KERN_DEBUG "- File encryptable type (regular/immediate)\n");
		if (src_encrypt && dest_encrypt) {
			dbg_cr(KERN_DEBUG "- File moving inside /encrypt (no change))\n");
		} else if (src_encrypt) {
			dbg_cr(KERN_DEBUG "- File moving out of /encrypt. Decrypting..\n");
			goto cryptstart;
		} else if (dest_encrypt) {
			dbg_cr(KERN_DEBUG "- File moving into /encrypt. Encrypting..\n");
			goto cryptstart;
		} else {
			dbg_cr(KERN_DEBUG "- Src/dest directories not encryptable\n");
		}
	} else {
		dbg_cr(KERN_DEBUG "- File not an encryptable type\n");
	}
	goto cryptdone;

/* encrypt/decrypt file */
cryptstart: 
	// open file
	if (!path_src)
		goto cryptfail;
	fcrypt = kfile_open(path_src, O_RDWR);
	if (!fcrypt)
		goto cryptfail;
	fsize = FILP_FSIZE(fcrypt);
	fremaining = fsize;
	fpos = 0;
	fseekpos = 0;
	dbg_cr(KERN_DEBUG " - Opened %s (Fsize: %d)\n", 
		FILP_NAME(fcrypt), fsize);
	// special case: nothing to encrypt
	if (fsize==0) 
		goto cryptclose;
	// loop: read, encrypt, write
	while (fremaining > 0) {
		// choose a chunk size
		nchunk = (fremaining > blocksize ? blocksize : (ssize_t)fremaining);
		dbg_cr(KERN_DEBUG " - Starting a %d-byte chunk at pos %u.\n", 
			(int)nchunk, (unsigned int)fpos);
		// read a chunk; make sure we read all bytes requested.
		fpos = fseekpos;
		nread = kfile_read(fcrypt, buf, (size_t)nchunk, &fpos);
		//	this inequality covers error conditions (nread<0) and 
		//	partial reads (0<=nread<=nchunk && nread != nchunk)
		if (nread != nchunk) {
			kfile_close(fcrypt);
			goto cryptfail;
		}
		// encrypt the buffer
		for (i=0; i<nchunk; i++)
			buf[i] ^= crypter_key;
		// write the chunk back
		fpos = fseekpos;
		nwritten = kfile_write(fcrypt, buf, (size_t)nchunk, &fpos);
		if (nwritten != nchunk) {
			kfile_close(fcrypt);
			goto cryptfail;
		}
		// move the file marker forward, decrease the #bytes remaining
		fseekpos += nchunk;
		fremaining -= nchunk;
	}
	// sync the read/write operations to disk. Very important!
	kfile_sync(fcrypt);

cryptclose:
	kfile_close(fcrypt);
	goto cryptdone;

cryptfail:
	// encrypt/decrypt failed
	if (dest_encrypt)
		printk(KERN_WARNING "Crypting file entering /%s failed: ino %lu\n",
				crypter_dir, INODE_INO(old_inode));
	else if (src_encrypt)
		printk(KERN_WARNING "Decrypting file leaving /%s failed: ino %lu\n",
				crypter_dir, INODE_INO(old_inode));
	goto cryptdone;

cryptdone:
	/*
	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
	 */
	old_inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(old_inode);

	ext2_delete_entry (old_de, old_page);

	if (dir_de) {
		if (old_dir != new_dir)
			ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
		else {
			kunmap(dir_page);
			page_cache_release(dir_page);
		}
		inode_dec_link_count(old_dir);
	}
	goto out_free;

out_dir:
	if (dir_de) {
		kunmap(dir_page);
		page_cache_release(dir_page);
	}
out_old:
	kunmap(old_page);
	page_cache_release(old_page);
out:
	return err;
out_free:
	// free buffers
	kfree(strbuf1);
	kfree(strbuf2);
	kfree(buf);
	return 0;
}