/* We need to start a transaction to maintain lock ordering */
int reiserfs_xattr_set(struct inode *inode, const char *name,
		       const void *buffer, size_t buffer_size, int flags)
{

	struct reiserfs_transaction_handle th;
	int error, error2;
	size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);

	if (!(flags & XATTR_REPLACE))
		jbegin_count += reiserfs_xattr_jcreate_nblocks(inode);

	reiserfs_write_lock(inode->i_sb);
	error = journal_begin(&th, inode->i_sb, jbegin_count);
	reiserfs_write_unlock(inode->i_sb);
	if (error) {
		return error;
	}

	error = reiserfs_xattr_set_handle(&th, inode, name,
					  buffer, buffer_size, flags);

	reiserfs_write_lock(inode->i_sb);
	error2 = journal_end(&th, inode->i_sb, jbegin_count);
	reiserfs_write_unlock(inode->i_sb);
	if (error == 0)
		error = error2;

	return error;
}

static int reiserfs_link(struct dentry *old_dentry, struct inode *dir,
			 struct dentry *dentry)
{
	int retval;
	struct inode *inode = d_inode(old_dentry);
	struct reiserfs_transaction_handle th;
	/*
	 * We need blocks for transaction + update of quotas for
	 * the owners of the directory
	 */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);

	retval = dquot_initialize(dir);
	if (retval)
		return retval;

	reiserfs_write_lock(dir->i_sb);
	if (inode->i_nlink >= REISERFS_LINK_MAX) {
		/* FIXME: sd_nlink is 32 bit for new files */
		reiserfs_write_unlock(dir->i_sb);
		return -EMLINK;
	}

	/* inc before scheduling so reiserfs_unlink knows we are here */
	inc_nlink(inode);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_nlink(inode);
		reiserfs_write_unlock(dir->i_sb);
		return retval;
	}

	/* create new entry */
	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	if (retval) {
		int err;
		drop_nlink(inode);
		err = journal_end(&th);
		reiserfs_write_unlock(dir->i_sb);
		return err ? err : retval;
	}

	inode->i_ctime = current_time(inode);
	reiserfs_update_sd(&th, inode);

	ihold(inode);
	d_instantiate(dentry, inode);
	retval = journal_end(&th);
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static int lookup_and_delete_xattr(struct inode *inode, const char *name)
{
	int err = 0;
	struct dentry *dentry, *xadir;

	xadir = open_xa_dir(inode, XATTR_REPLACE);
	if (IS_ERR(xadir))
		return PTR_ERR(xadir);

	mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
	dentry = lookup_one_len(name, xadir, strlen(name));
	if (IS_ERR(dentry)) {
		err = PTR_ERR(dentry);
		goto out_dput;
	}

	if (dentry->d_inode) {
		reiserfs_write_lock(inode->i_sb);
		err = xattr_unlink(xadir->d_inode, dentry);
		reiserfs_write_unlock(inode->i_sb);
		update_ctime(inode);
	}

	dput(dentry);
out_dput:
	mutex_unlock(&xadir->d_inode->i_mutex);
	dput(xadir);
	return err;
}

/* 
** looks up the dentry of the parent directory for child.
** taken from ext2_get_parent
*/
struct dentry *reiserfs_get_parent(struct dentry *child)
{
    int retval;
    struct inode * inode = NULL;
    struct reiserfs_dir_entry de;
    INITIALIZE_PATH (path_to_entry);
    struct dentry *parent;
    struct inode *dir = child->d_inode ;


    if (dir->i_nlink == 0) {
	return ERR_PTR(-ENOENT);
    }
    de.de_gen_number_bit_string = NULL;

    reiserfs_write_lock(dir->i_sb);
    retval = reiserfs_find_entry (dir, "..", 2, &path_to_entry, &de);
    pathrelse (&path_to_entry);
    if (retval != NAME_FOUND) {
	reiserfs_write_unlock(dir->i_sb);
	return ERR_PTR(-ENOENT);
    }
    inode = reiserfs_iget (dir->i_sb, (struct cpu_key *)&(de.de_dir_id));
    reiserfs_write_unlock(dir->i_sb);

    if (!inode || IS_ERR(inode)) {
	return ERR_PTR(-EACCES);
    }
    parent = d_alloc_anon(inode);
    if (!parent) {
	iput(inode);
	parent = ERR_PTR(-ENOMEM);
    }
    return parent;
}

/*
** looks up the dentry of the parent directory for child.
** taken from ext2_get_parent
*/
struct dentry *reiserfs_get_parent(struct dentry *child)
{
	int retval;
	struct inode *inode = NULL;
	struct reiserfs_dir_entry de;
	INITIALIZE_PATH(path_to_entry);
	struct inode *dir = child->d_inode;

	if (dir->i_nlink == 0) {
		return ERR_PTR(-ENOENT);
	}
	de.de_gen_number_bit_string = NULL;

	reiserfs_write_lock(dir->i_sb);
	retval = reiserfs_find_entry(dir, "..", 2, &path_to_entry, &de);
	pathrelse(&path_to_entry);
	if (retval != NAME_FOUND) {
		reiserfs_write_unlock(dir->i_sb);
		return ERR_PTR(-ENOENT);
	}
	inode = reiserfs_iget(dir->i_sb, (struct cpu_key *)&(de.de_dir_id));
	reiserfs_write_unlock(dir->i_sb);

	return d_obtain_alias(inode);
}

int reiserfs_unpack(struct inode *inode, struct file *filp)
{
	int retval = 0;
	int index;
	struct page *page;
	struct address_space *mapping;
	unsigned long write_from;
	unsigned long blocksize = inode->i_sb->s_blocksize;

	if (inode->i_size == 0) {
		REISERFS_I(inode)->i_flags |= i_nopack_mask;
		return 0;
	}
	/* ioctl already done */
	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
		return 0;
	}

	/* we need to make sure nobody is changing the file size beneath
	 ** us
	 */
	mutex_lock(&inode->i_mutex);
	reiserfs_write_lock(inode->i_sb);

	write_from = inode->i_size & (blocksize - 1);
	/* if we are on a block boundary, we are already unpacked.  */
	if (write_from == 0) {
		REISERFS_I(inode)->i_flags |= i_nopack_mask;
		goto out;
	}

	/* we unpack by finding the page with the tail, and calling
	 ** reiserfs_prepare_write on that page.  This will force a
	 ** reiserfs_get_block to unpack the tail for us.
	 */
	index = inode->i_size >> PAGE_CACHE_SHIFT;
	mapping = inode->i_mapping;
	page = grab_cache_page(mapping, index);
	retval = -ENOMEM;
	if (!page) {
		goto out;
	}
	retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
	if (retval)
		goto out_unlock;

	/* conversion can change page contents, must flush */
	flush_dcache_page(page);
	retval = reiserfs_commit_write(NULL, page, write_from, write_from);
	REISERFS_I(inode)->i_flags |= i_nopack_mask;

      out_unlock:
	unlock_page(page);
	page_cache_release(page);

      out:
	mutex_unlock(&inode->i_mutex);
	reiserfs_write_unlock(inode->i_sb);
	return retval;
}

static int reiserfs_link(struct dentry *old_dentry, struct inode *dir,
			 struct dentry *dentry)
{
	int retval;
	struct inode *inode = old_dentry->d_inode;
	struct reiserfs_transaction_handle th;
	/* We need blocks for transaction + update of quotas for the owners of the directory */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);

	reiserfs_write_lock(dir->i_sb);
	if (inode->i_nlink >= REISERFS_LINK_MAX) {
		//FIXME: sd_nlink is 32 bit for new files
		reiserfs_write_unlock(dir->i_sb);
		return -EMLINK;
	}
	if (inode->i_nlink == 0) {
		reiserfs_write_unlock(dir->i_sb);
		return -ENOENT;
	}

	/* inc before scheduling so reiserfs_unlink knows we are here */
	inode->i_nlink++;

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		inode->i_nlink--;
		reiserfs_write_unlock(dir->i_sb);
		return retval;
	}

	/* create new entry */
	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	if (retval) {
		int err;
		inode->i_nlink--;
		err = journal_end(&th, dir->i_sb, jbegin_count);
		reiserfs_write_unlock(dir->i_sb);
		return err ? err : retval;
	}

	inode->i_ctime = CURRENT_TIME_SEC;
	reiserfs_update_sd(&th, inode);

	atomic_inc(&inode->i_count);
	d_instantiate(dentry, inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static int reiserfs_create (struct inode * dir, struct dentry *dentry, int mode,
		struct nameidata *nd)
{
    int retval;
    struct inode * inode;
    int jbegin_count = JOURNAL_PER_BALANCE_CNT * 2 ;
    struct reiserfs_transaction_handle th ;
    int locked;

    if (!(inode = new_inode(dir->i_sb))) {
	return -ENOMEM ;
    }
    retval = new_inode_init(inode, dir, mode);
    if (retval)
        return retval;

    locked = reiserfs_cache_default_acl (dir);

    reiserfs_write_lock(dir->i_sb);

    if (locked)
        reiserfs_write_lock_xattrs (dir->i_sb);

    journal_begin(&th, dir->i_sb, jbegin_count) ;
    retval = reiserfs_new_inode (&th, dir, mode, 0, 0/*i_size*/, dentry, inode);

    if (locked)
        reiserfs_write_unlock_xattrs (dir->i_sb);

    if (retval) {
        goto out_failed;
    }
	
    inode->i_op = &reiserfs_file_inode_operations;
    inode->i_fop = &reiserfs_file_operations;
    inode->i_mapping->a_ops = &reiserfs_address_space_operations ;

    retval = reiserfs_add_entry (&th, dir, dentry->d_name.name, dentry->d_name.len, 
				inode, 1/*visible*/);
    if (retval) {
	inode->i_nlink--;
	reiserfs_update_sd (&th, inode);
	journal_end(&th, dir->i_sb, jbegin_count) ;
	iput (inode);
	goto out_failed;
    }
    reiserfs_update_inode_transaction(inode) ;
    reiserfs_update_inode_transaction(dir) ;

    d_instantiate(dentry, inode);
    journal_end(&th, dir->i_sb, jbegin_count) ;

out_failed:
    reiserfs_write_unlock(dir->i_sb);
    return retval;
}

int
reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	int error, error2;
	struct reiserfs_transaction_handle th;
	size_t jcreate_blocks;
	int size = acl ? posix_acl_xattr_size(acl->a_count) : 0;
	int update_mode = 0;
	umode_t mode = inode->i_mode;

	/*
	 * Pessimism: We can't assume that anything from the xattr root up
	 * has been created.
	 */

	jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
			 reiserfs_xattr_nblocks(inode, size) * 2;

	reiserfs_write_lock(inode->i_sb);
	error = journal_begin(&th, inode->i_sb, jcreate_blocks);
	reiserfs_write_unlock(inode->i_sb);
	if (error == 0) {
		if (type == ACL_TYPE_ACCESS && acl) {
			error = posix_acl_update_mode(inode, &mode, &acl);
			if (error)
				goto unlock;
			update_mode = 1;
		}
		error = __reiserfs_set_acl(&th, inode, type, acl);
		if (!error && update_mode)
			inode->i_mode = mode;
unlock:
		reiserfs_write_lock(inode->i_sb);
		error2 = journal_end(&th);
		reiserfs_write_unlock(inode->i_sb);
		if (error2)
			error = error2;
	}

	return error;
}

static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
				      struct nameidata *nd)
{
	int retval;
	struct inode *inode = NULL;
	struct reiserfs_dir_entry de;
	INITIALIZE_PATH(path_to_entry);

	if (REISERFS_MAX_NAME(dir->i_sb->s_blocksize) < dentry->d_name.len)
		return ERR_PTR(-ENAMETOOLONG);

	reiserfs_write_lock(dir->i_sb);
	de.de_gen_number_bit_string = NULL;
	retval =
	    reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len,
				&path_to_entry, &de);
	pathrelse(&path_to_entry);
	if (retval == NAME_FOUND) {
		/* Hide the .reiserfs_priv directory */
		if (reiserfs_xattrs(dir->i_sb) &&
		    !old_format_only(dir->i_sb) &&
		    REISERFS_SB(dir->i_sb)->priv_root &&
		    REISERFS_SB(dir->i_sb)->priv_root->d_inode &&
		    de.de_objectid ==
		    le32_to_cpu(INODE_PKEY
				(REISERFS_SB(dir->i_sb)->priv_root->d_inode)->
				k_objectid)) {
			reiserfs_write_unlock(dir->i_sb);
			return ERR_PTR(-EACCES);
		}

		inode =
		    reiserfs_iget(dir->i_sb, (struct cpu_key *)&(de.de_dir_id));
		if (!inode || IS_ERR(inode)) {
			reiserfs_write_unlock(dir->i_sb);
			return ERR_PTR(-EACCES);
		}

		/* Propogate the priv_object flag so we know we're in the priv tree */
		if (is_reiserfs_priv_object(dir))
			reiserfs_mark_inode_private(inode);
	}
	reiserfs_write_unlock(dir->i_sb);
	if (retval == IO_ERROR) {
		return ERR_PTR(-EIO);
	}

	return d_splice_alias(inode, dentry);
}

static int
posix_acl_set(struct dentry *dentry, const char *name, const void *value,
		size_t size, int flags, int type)
{
	struct inode *inode = dentry->d_inode;
	struct posix_acl *acl;
	int error, error2;
	struct reiserfs_transaction_handle th;
	size_t jcreate_blocks;
	if (!reiserfs_posixacl(inode->i_sb))
		return -EOPNOTSUPP;
	if (!inode_owner_or_capable(inode))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(&init_user_ns, value, size);
		if (IS_ERR(acl)) {
			return PTR_ERR(acl);
		} else if (acl) {
			error = posix_acl_valid(acl);
			if (error)
				goto release_and_out;
		}
	} else
		acl = NULL;

	/* Pessimism: We can't assume that anything from the xattr root up
	 * has been created. */

	jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
			 reiserfs_xattr_nblocks(inode, size) * 2;

	reiserfs_write_lock(inode->i_sb);
	error = journal_begin(&th, inode->i_sb, jcreate_blocks);
	if (error == 0) {
		error = reiserfs_set_acl(&th, inode, type, acl);
		error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
		if (error2)
			error = error2;
	}
	reiserfs_write_unlock(inode->i_sb);

      release_and_out:
	posix_acl_release(acl);
	return error;
}

static int reiserfs_sync_file(
			      struct file   * p_s_filp,
			      struct dentry * p_s_dentry,
			      int datasync
			      ) {
  struct inode * p_s_inode = p_s_dentry->d_inode;
  int n_err;

  reiserfs_write_lock(p_s_inode->i_sb);

  if (!S_ISREG(p_s_inode->i_mode))
      BUG ();

  n_err = sync_mapping_buffers(p_s_inode->i_mapping) ;
  reiserfs_commit_for_inode(p_s_inode) ;
  reiserfs_write_unlock(p_s_inode->i_sb);
  return ( n_err < 0 ) ? -EIO : 0;
}

static int reiserfs_dir_fsync(struct file *filp, loff_t start, loff_t end,
			      int datasync)
{
	struct inode *inode = filp->f_mapping->host;
	int err;

	err = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (err)
		return err;

	mutex_lock(&inode->i_mutex);
	reiserfs_write_lock(inode->i_sb);
	err = reiserfs_commit_for_inode(inode);
	reiserfs_write_unlock(inode->i_sb);
	mutex_unlock(&inode->i_mutex);
	if (err < 0)
		return err;
	return 0;
}

static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
				      unsigned int flags)
{
	int retval;
	struct inode *inode = NULL;
	struct reiserfs_dir_entry de;
	INITIALIZE_PATH(path_to_entry);

	if (REISERFS_MAX_NAME(dir->i_sb->s_blocksize) < dentry->d_name.len)
		return ERR_PTR(-ENAMETOOLONG);

	reiserfs_write_lock(dir->i_sb);

	de.de_gen_number_bit_string = NULL;
	retval =
	    reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len,
				&path_to_entry, &de);
	pathrelse(&path_to_entry);
	if (retval == NAME_FOUND) {
		inode = reiserfs_iget(dir->i_sb,
				      (struct cpu_key *)&de.de_dir_id);
		if (!inode || IS_ERR(inode)) {
			reiserfs_write_unlock(dir->i_sb);
			return ERR_PTR(-EACCES);
		}

		/*
		 * Propagate the private flag so we know we're
		 * in the priv tree
		 */
		if (IS_PRIVATE(dir))
			inode->i_flags |= S_PRIVATE;
	}
	reiserfs_write_unlock(dir->i_sb);
	if (retval == IO_ERROR) {
		return ERR_PTR(-EIO);
	}

	return d_splice_alias(inode, dentry);
}

/*
** We pack the tails of files on file close, not at the time they are written.
** This implies an unnecessary copy of the tail and an unnecessary indirect item
** insertion/balancing, for files that are written in one write.
** It avoids unnecessary tail packings (balances) for files that are written in
** multiple writes and are small enough to have tails.
** 
** file_release is called by the VFS layer when the file is closed.  If
** this is the last open file descriptor, and the file
** small enough to have a tail, and the tail is currently in an
** unformatted node, the tail is converted back into a direct item.
** 
** We use reiserfs_truncate_file to pack the tail, since it already has
** all the conditions coded.  
*/
static int reiserfs_file_release (struct inode * inode, struct file * filp)
{

    struct reiserfs_transaction_handle th ;

    if (!S_ISREG (inode->i_mode))
	BUG ();

    /* fast out for when nothing needs to be done */
    if ((atomic_read(&inode->i_count) > 1 ||
	!(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) || 
         !tail_has_to_be_packed(inode))       && 
	REISERFS_I(inode)->i_prealloc_count <= 0) {
	return 0;
    }    
    
    reiserfs_write_lock(inode->i_sb);
    down (&inode->i_sem); 
    journal_begin(&th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3) ;
    reiserfs_update_inode_transaction(inode) ;

#ifdef REISERFS_PREALLOCATE
    reiserfs_discard_prealloc (&th, inode);
#endif
    journal_end(&th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3) ;

    if (atomic_read(&inode->i_count) <= 1 &&
	(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) &&
        tail_has_to_be_packed (inode)) {
	/* if regular file is released by last holder and it has been
	   appended (we append by unformatted node only) or its direct
	   item(s) had to be converted, then it may have to be
	   indirect2direct converted */
	reiserfs_truncate_file(inode, 0) ;
    }
    up (&inode->i_sem); 
    reiserfs_write_unlock(inode->i_sb);
    return 0;
}

int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
			   filldir_t filldir, loff_t *pos)
{
	struct inode *inode = dentry->d_inode;
	struct cpu_key pos_key;	/* key of current position in the directory (key of directory entry) */
	INITIALIZE_PATH(path_to_entry);
	struct buffer_head *bh;
	int item_num, entry_num;
	const struct reiserfs_key *rkey;
	struct item_head *ih, tmp_ih;
	int search_res;
	char *local_buf;
	loff_t next_pos;
	char small_buf[32];	/* avoid kmalloc if we can */
	struct reiserfs_dir_entry de;
	int ret = 0;

	reiserfs_write_lock(inode->i_sb);

	reiserfs_check_lock_depth(inode->i_sb, "readdir");

	/* form key for search the next directory entry using f_pos field of
	   file structure */
	make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
	next_pos = cpu_key_k_offset(&pos_key);

	path_to_entry.reada = PATH_READA;
	while (1) {
	      research:
		/* search the directory item, containing entry with specified key */
		search_res =
		    search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
					&de);
		if (search_res == IO_ERROR) {
			// FIXME: we could just skip part of directory which could
			// not be read
			ret = -EIO;
			goto out;
		}
		entry_num = de.de_entry_num;
		bh = de.de_bh;
		item_num = de.de_item_num;
		ih = de.de_ih;
		store_ih(&tmp_ih, ih);

		/* we must have found item, that is item of this directory, */
		RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
		       "vs-9000: found item %h does not match to dir we readdir %K",
		       ih, &pos_key);
		RFALSE(item_num > B_NR_ITEMS(bh) - 1,
		       "vs-9005 item_num == %d, item amount == %d",
		       item_num, B_NR_ITEMS(bh));

		/* and entry must be not more than number of entries in the item */
		RFALSE(I_ENTRY_COUNT(ih) < entry_num,
		       "vs-9010: entry number is too big %d (%d)",
		       entry_num, I_ENTRY_COUNT(ih));

		if (search_res == POSITION_FOUND
		    || entry_num < I_ENTRY_COUNT(ih)) {
			/* go through all entries in the directory item beginning from the entry, that has been found */
			struct reiserfs_de_head *deh =
			    B_I_DEH(bh, ih) + entry_num;

			for (; entry_num < I_ENTRY_COUNT(ih);
			     entry_num++, deh++) {
				int d_reclen;
				char *d_name;
				off_t d_off;
				ino_t d_ino;
				loff_t cur_pos = deh_offset(deh);

				if (!de_visible(deh))
					/* it is hidden entry */
					continue;
				d_reclen = entry_length(bh, ih, entry_num);
				d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);

				if (d_reclen <= 0 ||
				    d_name + d_reclen > bh->b_data + bh->b_size) {
					/* There is corrupted data in entry,
					 * We'd better stop here */
					pathrelse(&path_to_entry);
					ret = -EIO;
					goto out;
				}

				if (!d_name[d_reclen - 1])
					d_reclen = strlen(d_name);

				if (d_reclen >
				    REISERFS_MAX_NAME(inode->i_sb->
						      s_blocksize)) {
					/* too big to send back to VFS */
					continue;
				}

				/* Ignore the .reiserfs_priv entry */
				if (is_privroot_deh(dentry, deh))
					continue;
//.........这里部分代码省略.........

int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
			   filldir_t filldir, loff_t *pos)
{
	struct inode *inode = dentry->d_inode;
	struct cpu_key pos_key;	
	INITIALIZE_PATH(path_to_entry);
	struct buffer_head *bh;
	int item_num, entry_num;
	const struct reiserfs_key *rkey;
	struct item_head *ih, tmp_ih;
	int search_res;
	char *local_buf;
	loff_t next_pos;
	char small_buf[32];	
	struct reiserfs_dir_entry de;
	int ret = 0;

	reiserfs_write_lock(inode->i_sb);

	reiserfs_check_lock_depth(inode->i_sb, "readdir");

	make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
	next_pos = cpu_key_k_offset(&pos_key);

	path_to_entry.reada = PATH_READA;
	while (1) {
	      research:
		
		search_res =
		    search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
					&de);
		if (search_res == IO_ERROR) {
			
			
			ret = -EIO;
			goto out;
		}
		entry_num = de.de_entry_num;
		bh = de.de_bh;
		item_num = de.de_item_num;
		ih = de.de_ih;
		store_ih(&tmp_ih, ih);

		
		RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
		       "vs-9000: found item %h does not match to dir we readdir %K",
		       ih, &pos_key);
		RFALSE(item_num > B_NR_ITEMS(bh) - 1,
		       "vs-9005 item_num == %d, item amount == %d",
		       item_num, B_NR_ITEMS(bh));

		
		RFALSE(I_ENTRY_COUNT(ih) < entry_num,
		       "vs-9010: entry number is too big %d (%d)",
		       entry_num, I_ENTRY_COUNT(ih));

		if (search_res == POSITION_FOUND
		    || entry_num < I_ENTRY_COUNT(ih)) {
			
			struct reiserfs_de_head *deh =
			    B_I_DEH(bh, ih) + entry_num;

			for (; entry_num < I_ENTRY_COUNT(ih);
			     entry_num++, deh++) {
				int d_reclen;
				char *d_name;
				off_t d_off;
				ino_t d_ino;

				if (!de_visible(deh))
					
					continue;
				d_reclen = entry_length(bh, ih, entry_num);
				d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);

				if (d_reclen <= 0 ||
				    d_name + d_reclen > bh->b_data + bh->b_size) {
					pathrelse(&path_to_entry);
					ret = -EIO;
					goto out;
				}

				if (!d_name[d_reclen - 1])
					d_reclen = strlen(d_name);

				if (d_reclen >
				    REISERFS_MAX_NAME(inode->i_sb->
						      s_blocksize)) {
					
					continue;
				}

				
				if (is_privroot_deh(dentry, deh))
					continue;

				d_off = deh_offset(deh);
				*pos = d_off;
				d_ino = deh_objectid(deh);
				if (d_reclen <= 32) {
//.........这里部分代码省略.........

static int reiserfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	int retval, err;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	int jbegin_count;
	INITIALIZE_PATH(path);
	struct reiserfs_dir_entry de;

	/* we will be doing 2 balancings and update 2 stat data, we change quotas
	 * of the owner of the directory and of the owner of the parent directory.
	 * The quota structure is possibly deleted only on last iput => outside
	 * of this transaction */
	jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 2 + 2 +
	    4 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);

	dquot_initialize(dir);

	reiserfs_write_lock(dir->i_sb);
	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval)
		goto out_rmdir;

	de.de_gen_number_bit_string = NULL;
	if ((retval =
	     reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len,
				 &path, &de)) == NAME_NOT_FOUND) {
		retval = -ENOENT;
		goto end_rmdir;
	} else if (retval == IO_ERROR) {
		retval = -EIO;
		goto end_rmdir;
	}

	inode = dentry->d_inode;

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	if (de.de_objectid != inode->i_ino) {
		// FIXME: compare key of an object and a key found in the
		// entry
		retval = -EIO;
		goto end_rmdir;
	}
	if (!reiserfs_empty_dir(inode)) {
		retval = -ENOTEMPTY;
		goto end_rmdir;
	}

	/* cut entry from dir directory */
	retval = reiserfs_cut_from_item(&th, &path, &(de.de_entry_key), dir, NULL,	/* page */
					0 /*new file size - not used here */ );
	if (retval < 0)
		goto end_rmdir;

	if (inode->i_nlink != 2 && inode->i_nlink != 1)
		reiserfs_error(inode->i_sb, "reiserfs-7040",
			       "empty directory has nlink != 2 (%d)",
			       inode->i_nlink);

	clear_nlink(inode);
	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
	reiserfs_update_sd(&th, inode);

	DEC_DIR_INODE_NLINK(dir)
	    dir->i_size -= (DEH_SIZE + de.de_entrylen);
	reiserfs_update_sd(&th, dir);

	/* prevent empty directory from getting lost */
	add_save_link(&th, inode, 0 /* not truncate */ );

	retval = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_check_path(&path);
      out_rmdir:
	reiserfs_write_unlock(dir->i_sb);
	return retval;

      end_rmdir:
	/* we must release path, because we did not call
	   reiserfs_cut_from_item, or reiserfs_cut_from_item does not
	   release path if operation was not complete */
	pathrelse(&path);
	err = journal_end(&th, dir->i_sb, jbegin_count);
	reiserfs_write_unlock(dir->i_sb);
	return err ? err : retval;
}

static int reiserfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
			  dev_t rdev)
{
	int retval;
	struct inode *inode;
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 3 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));

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

	dquot_initialize(dir);

	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	jbegin_count += reiserfs_cache_default_acl(dir);
	retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
	if (retval < 0) {
		drop_new_inode(inode);
		return retval;
	}
	jbegin_count += retval;
	reiserfs_write_lock(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, dir, mode, NULL, 0 /*i_size */ , dentry,
			       inode, &security);
	if (retval) {
		goto out_failed;
	}

	inode->i_op = &reiserfs_special_inode_operations;
	init_special_inode(inode, inode->i_mode, rdev);

	//FIXME: needed for block and char devices only
	reiserfs_update_sd(&th, inode);

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		drop_nlink(inode);
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		unlock_new_inode(inode);
		iput(inode);
		goto out_failed;
	}

	unlock_new_inode(inode);
	d_instantiate(dentry, inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);

      out_failed:
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}

static int reiserfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
			   struct nameidata *nd)
{
	int retval;
	struct inode *inode;
	/* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
	int jbegin_count =
	    JOURNAL_PER_BALANCE_CNT * 2 +
	    2 * (REISERFS_QUOTA_INIT_BLOCKS(dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb));
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;

	dquot_initialize(dir);

	if (!(inode = new_inode(dir->i_sb))) {
		return -ENOMEM;
	}
	new_inode_init(inode, dir, mode);

	jbegin_count += reiserfs_cache_default_acl(dir);
	retval = reiserfs_security_init(dir, inode, &dentry->d_name, &security);
	if (retval < 0) {
		drop_new_inode(inode);
		return retval;
	}
	jbegin_count += retval;
	reiserfs_write_lock(dir->i_sb);

	retval = journal_begin(&th, dir->i_sb, jbegin_count);
	if (retval) {
		drop_new_inode(inode);
		goto out_failed;
	}

	retval =
	    reiserfs_new_inode(&th, dir, mode, NULL, 0 /*i_size */ , dentry,
			       inode, &security);
	if (retval)
		goto out_failed;

	inode->i_op = &reiserfs_file_inode_operations;
	inode->i_fop = &reiserfs_file_operations;
	inode->i_mapping->a_ops = &reiserfs_address_space_operations;

	retval =
	    reiserfs_add_entry(&th, dir, dentry->d_name.name,
			       dentry->d_name.len, inode, 1 /*visible */ );
	if (retval) {
		int err;
		drop_nlink(inode);
		reiserfs_update_sd(&th, inode);
		err = journal_end(&th, dir->i_sb, jbegin_count);
		if (err)
			retval = err;
		unlock_new_inode(inode);
		iput(inode);
		goto out_failed;
	}
	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(dir);

	unlock_new_inode(inode);
	d_instantiate(dentry, inode);
	retval = journal_end(&th, dir->i_sb, jbegin_count);

      out_failed:
	reiserfs_write_unlock(dir->i_sb);
	return retval;
}