C++ reiserfs_update_inode_transaction函数代码示例

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;
}

int reiserfs_link (struct dentry * old_dentry, struct inode * dir, struct dentry * dentry)
{
  struct inode *inode = old_dentry->d_inode;
  struct path path_to_entry;
  struct reiserfs_dir_entry de;
  int error;
  int windex ;
  struct reiserfs_transaction_handle th ;
  int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3; 
  
  init_path (&path_to_entry);

  /* object must not be directory */
  if (S_ISDIR(inode->i_mode)) {
    return -EPERM;
  }
  
  /* file has too many links */
  if (inode->i_nlink >= REISERFS_LINK_MAX) {
    return -EMLINK;
  }

  journal_begin(&th, dir->i_sb, jbegin_count) ;
  windex = push_journal_writer("reiserfs_link") ;

  reiserfs_update_inode_transaction(inode) ;
  reiserfs_update_inode_transaction(dir) ;

  de.de_gen_number_bit_string = 0;
  if (reiserfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &path_to_entry, &de) == POSITION_FOUND) {
    pathrelse (&path_to_entry);
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    return -EEXIST;
  }
  
  pathrelse (&path_to_entry);

  /* free preserve list if we should */
/*  maybe_free_preserve_list (dir->i_sb);*/

  /* create new entry */
  error = reiserfs_add_entry (&th, dir, dentry->d_name.name, dentry->d_name.len, INODE_PKEY (inode), &de, 1);
  if (error) {
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    return error;
  }
  inode->i_nlink++;
  inode->i_ctime = CURRENT_TIME;
  if_in_ram_update_sd (&th, inode);
  if_in_ram_update_sd (&th, dir);
  inode->i_count++;
  d_instantiate(dentry, inode);
  pop_journal_writer(windex) ;
  journal_end(&th, dir->i_sb, jbegin_count) ;
  return 0;
}

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_create (struct inode * dir, struct dentry *dentry, int mode)
{
  int error;
  struct inode * inode;
  struct reiserfs_dir_entry de;
  int windex ;
  int jbegin_count = JOURNAL_PER_BALANCE_CNT * 2 ;
  struct reiserfs_transaction_handle th ;
  int err;
	
  if (!dir)
    return -ENOENT;
	
  inode = get_empty_inode() ;
  if (!inode) {
    return -ENOSPC ;
  }
  journal_begin(&th, dir->i_sb, jbegin_count) ;
  th.t_caller = "create" ;
  windex = push_journal_writer("reiserfs_create") ;
  inode = reiserfs_new_inode (&th, dir, mode, 0, dentry, inode, &err);
  if (!inode) {
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    return err;
  }
  reiserfs_update_inode_transaction(inode) ;
  reiserfs_update_inode_transaction(dir) ;
	
  inode->i_op = &reiserfs_file_inode_operations;
  inode->i_mode = mode;

  error = reiserfs_add_entry (&th, dir, dentry->d_name.name, dentry->d_name.len, INODE_PKEY (inode), &de, 1);
  if (error) {
    inode->i_nlink--;
    if_in_ram_update_sd (&th, inode);
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    iput (inode);
    return error;
  }
  if_in_ram_update_sd (&th, dir); 
  d_instantiate(dentry, inode);
  pop_journal_writer(windex) ;
  journal_end(&th, dir->i_sb, jbegin_count) ;
  return 0;
}

static int reiserfs_symlink(struct inode *parent_dir,
			    struct dentry *dentry, const char *symname)
{
	int retval;
	struct inode *inode;
	char *name;
	int item_len;
	struct reiserfs_transaction_handle th;
	struct reiserfs_security_handle security;
	int mode = S_IFLNK | S_IRWXUGO;
	/* 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(parent_dir->i_sb) +
		 REISERFS_QUOTA_TRANS_BLOCKS(parent_dir->i_sb));

	dquot_initialize(parent_dir);

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

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

	reiserfs_write_lock(parent_dir->i_sb);
	item_len = ROUND_UP(strlen(symname));
	if (item_len > MAX_DIRECT_ITEM_LEN(parent_dir->i_sb->s_blocksize)) {
		retval = -ENAMETOOLONG;
		drop_new_inode(inode);
		goto out_failed;
	}

	name = kmalloc(item_len, GFP_NOFS);
	if (!name) {
		drop_new_inode(inode);
		retval = -ENOMEM;
		goto out_failed;
	}
	memcpy(name, symname, strlen(symname));
	padd_item(name, item_len, strlen(symname));

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

	retval =
	    reiserfs_new_inode(&th, parent_dir, mode, name, strlen(symname),
			       dentry, inode, &security);
	kfree(name);
	if (retval) {		/* reiserfs_new_inode iputs for us */
		goto out_failed;
	}

	reiserfs_update_inode_transaction(inode);
	reiserfs_update_inode_transaction(parent_dir);

	inode->i_op = &reiserfs_symlink_inode_operations;
	inode->i_mapping->a_ops = &reiserfs_address_space_operations;

	// must be sure this inode is written with this transaction
	//
	//reiserfs_update_sd (&th, inode, READ_BLOCKS);

	retval = reiserfs_add_entry(&th, parent_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, parent_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, parent_dir->i_sb, jbegin_count);
      out_failed:
	reiserfs_write_unlock(parent_dir->i_sb);
	return retval;
}

static int reiserfs_mkdir (struct inode * dir, struct dentry *dentry, int mode)
{
    int retval;
    struct inode * inode;
    struct reiserfs_transaction_handle th ;
    int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3; 
    int locked;

#ifdef DISPLACE_NEW_PACKING_LOCALITIES
    /* set flag that new packing locality created and new blocks for the content     * of that directory are not displaced yet */
    REISERFS_I(dir)->new_packing_locality = 1;
#endif
    mode = S_IFDIR | mode;
    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) ;

    /* inc the link count now, so another writer doesn't overflow it while
    ** we sleep later on.
    */
    INC_DIR_INODE_NLINK(dir)

    retval = reiserfs_new_inode (&th, dir, mode, 0/*symlink*/,
				old_format_only (dir->i_sb) ? 
				EMPTY_DIR_SIZE_V1 : EMPTY_DIR_SIZE,
				dentry, inode);
    if (locked)
        reiserfs_write_unlock_xattrs (dir->i_sb);

    if (retval) {
	dir->i_nlink-- ;
	goto out_failed;
    }
    reiserfs_update_inode_transaction(inode) ;
    reiserfs_update_inode_transaction(dir) ;

    inode->i_op = &reiserfs_dir_inode_operations;
    inode->i_fop = &reiserfs_dir_operations;

    // note, _this_ add_entry will not update dir's stat data
    retval = reiserfs_add_entry (&th, dir, dentry->d_name.name, dentry->d_name.len, 
				inode, 1/*visible*/);
    if (retval) {
	inode->i_nlink = 0;
	DEC_DIR_INODE_NLINK(dir);
	reiserfs_update_sd (&th, inode);
	journal_end(&th, dir->i_sb, jbegin_count) ;
	iput (inode);
	goto out_failed;
    }

    // the above add_entry did not update dir's stat data
    reiserfs_update_sd (&th, dir);

    d_instantiate(dentry, inode);
    journal_end(&th, dir->i_sb, jbegin_count) ;
out_failed:
    reiserfs_write_unlock(dir->i_sb);
    return retval;
}

static int reiserfs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
{
    int retval;
    struct inode * inode;
    struct reiserfs_transaction_handle th ;
    int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3; 
    int locked;

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

    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_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) {
	inode->i_nlink--;
	reiserfs_update_sd (&th, inode);
	journal_end(&th, dir->i_sb, jbegin_count) ;
	iput (inode);
	goto out_failed;
    }

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

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

int reiserfs_unlink (struct inode * dir, struct dentry *dentry)
{
  int retval;
  struct inode * inode;
  struct reiserfs_dir_entry de;
  struct path path;
  int windex ;
  int call_journal_end = 1 ;
  struct reiserfs_transaction_handle th ;
  int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3; 

  init_path (&path);

  retval = -ENOENT;
	
  journal_begin(&th, dir->i_sb, jbegin_count) ;
  windex = push_journal_writer("reiserfs_unlink") ;
  /* free preserve list if we should */
/*  maybe_free_preserve_list (dir->i_sb);*/
	
  de.de_gen_number_bit_string = 0;
  if (reiserfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &path, &de) == POSITION_NOT_FOUND) {
    goto end_unlink;
  }

  inode = dentry->d_inode;

  reiserfs_update_inode_transaction(inode) ;
  reiserfs_update_inode_transaction(dir) ;

  retval = -EPERM;
  if (S_ISDIR (inode->i_mode)) {
    goto end_unlink;
  }
  if ((dir->i_mode & S_ISVTX) && !fsuser() &&
      current->fsuid != inode->i_uid &&
      current->fsuid != dir->i_uid) {
    goto end_unlink;
  }

  retval = -ENOENT;
  if (comp_short_keys ((struct key *)&(de.de_dir_id), INODE_PKEY (inode))) {
    goto end_unlink;
  }
  
  if (!inode->i_nlink) {
    printk("reiserfs_unlink: deleting nonexistent file (%s:%lu), %d\n",
	   kdevname(inode->i_dev), inode->i_ino, inode->i_nlink);
    inode->i_nlink = 1;
  }
  if (reiserfs_cut_from_item (&th, dir, dir->i_sb, &path, &(de.de_entry_num), &(de.de_entry_key), 0, NOTHING_SPECIAL) == 0) {
    retval = -ENOENT;
    goto end_unlink;
  }

  inode->i_nlink--;
  inode->i_ctime = CURRENT_TIME;
  if_in_ram_update_sd (&th, inode);

  dir->i_size -= (de.de_entrylen + DEH_SIZE);
  dir->i_ctime = dir->i_mtime = CURRENT_TIME;
  if_in_ram_update_sd (&th, dir) ;
  pop_journal_writer(windex) ;
  journal_end(&th, dir->i_sb, jbegin_count) ;
  call_journal_end = 0 ;
  d_delete(dentry); 
  retval = 0;

end_unlink:
  pathrelse (&path);
  pop_journal_writer(windex) ;
  if (call_journal_end) 
    journal_end(&th, dir->i_sb, jbegin_count) ;
  return retval;
}

int reiserfs_symlink (struct inode * dir, struct dentry * dentry, const char * symname)
{
  struct inode * inode;
  struct path path_to_entry;
  struct reiserfs_dir_entry de;
  int error;
  int windex ;
  struct reiserfs_transaction_handle th ;
  int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3; 
  int err;

  init_path (&path_to_entry);
  if (strlen (symname) + 1 + SD_SIZE > MAX_ITEM_LEN (dir->i_sb->s_blocksize)) {
    return -ENAMETOOLONG;
  }
  inode = get_empty_inode() ;
  if (!inode) {
    return -ENOSPC ;
  }
 
  journal_begin(&th, dir->i_sb, jbegin_count) ;
  windex = push_journal_writer("reiserfs_symlink") ;
  inode = reiserfs_new_inode (&th, dir, S_IFLNK, symname, dentry, inode, &err);
  if (inode == 0) {
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    return err;
  }
  reiserfs_update_inode_transaction(inode) ;
  reiserfs_update_inode_transaction(dir) ;

  inode->i_op = &reiserfs_symlink_inode_operations;
  inode->i_size = strlen (symname);
  inode->i_mode = S_IFLNK | 0777;
  if_in_ram_update_sd (&th, inode);

  de.de_gen_number_bit_string = 0;
  if (reiserfs_find_entry (dir, dentry->d_name.name, dentry->d_name.len, &path_to_entry, &de) == POSITION_FOUND) {
    pathrelse (&path_to_entry);
    inode->i_nlink--;
    if_in_ram_update_sd (&th, inode);
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    iput (inode);
    return -EEXIST;
  }
  pathrelse (&path_to_entry);

  error = reiserfs_add_entry (&th, dir, dentry->d_name.name, dentry->d_name.len, INODE_PKEY (inode), &de, 1);
  if (error) {
    inode->i_nlink--;
    if_in_ram_update_sd (&th, inode);
    pop_journal_writer(windex) ;
    journal_end(&th, dir->i_sb, jbegin_count) ;
    iput (inode);
    return error;
  }
  if_in_ram_update_sd (&th, dir);
  d_instantiate(dentry, inode);
  pop_journal_writer(windex) ;
  journal_end(&th, dir->i_sb, jbegin_count) ;
  return 0;
}

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_rmdir (struct inode * dir, struct dentry *dentry)
{
    int retval;
    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 */
    jbegin_count = JOURNAL_PER_BALANCE_CNT * 2 + 2;

    reiserfs_write_lock(dir->i_sb);
    journal_begin(&th, dir->i_sb, jbegin_count) ;

    de.de_gen_number_bit_string = 0;
    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_warning (inode->i_sb, "%s: empty directory has nlink "
			  "!= 2 (%d)", __FUNCTION__, inode->i_nlink);

    inode->i_nlink = 0;
    inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
    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 */);

    journal_end(&th, dir->i_sb, jbegin_count) ;
    reiserfs_check_path(&path) ;
    reiserfs_write_unlock(dir->i_sb);
    return 0;
	
 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);
    journal_end(&th, dir->i_sb, jbegin_count) ;
    reiserfs_write_unlock(dir->i_sb);
    return 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;
}

//.........这里部分代码省略.........
		if (retval != NAME_FOUND) {
			reiserfs_write_unlock(old_dir->i_sb);
			return -EIO;
		}

		/* inode number of .. must equal old_dir->i_ino */
		if (dot_dot_de.de_objectid != old_dir->i_ino) {
			reiserfs_write_unlock(old_dir->i_sb);
			return -EIO;
		}
	}

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

	/* add new entry (or find the existing one) */
	retval =
	    reiserfs_add_entry(&th, new_dir, new_dentry->d_name.name,
			       new_dentry->d_name.len, old_inode, 0);
	if (retval == -EEXIST) {
		if (!new_dentry_inode) {
			reiserfs_panic(old_dir->i_sb, "vs-7050",
				       "new entry is found, new inode == 0");
		}
	} else if (retval) {
		int err = journal_end(&th, old_dir->i_sb, jbegin_count);
		reiserfs_write_unlock(old_dir->i_sb);
		return err ? err : retval;
	}

	reiserfs_update_inode_transaction(old_dir);
	reiserfs_update_inode_transaction(new_dir);

	/* this makes it so an fsync on an open fd for the old name will
	 ** commit the rename operation
	 */
	reiserfs_update_inode_transaction(old_inode);

	if (new_dentry_inode)
		reiserfs_update_inode_transaction(new_dentry_inode);

	while (1) {
		// look for old name using corresponding entry key (found by reiserfs_find_entry)
		if ((retval =
		     search_by_entry_key(new_dir->i_sb, &old_de.de_entry_key,
					 &old_entry_path,
					 &old_de)) != NAME_FOUND) {
			pathrelse(&old_entry_path);
			journal_end(&th, old_dir->i_sb, jbegin_count);
			reiserfs_write_unlock(old_dir->i_sb);
			return -EIO;
		}

		copy_item_head(&old_entry_ih, get_ih(&old_entry_path));

		reiserfs_prepare_for_journal(old_inode->i_sb, old_de.de_bh, 1);

		// look for new name by reiserfs_find_entry
		new_de.de_gen_number_bit_string = NULL;
		retval =
		    reiserfs_find_entry(new_dir, new_dentry->d_name.name,
					new_dentry->d_name.len, &new_entry_path,
					&new_de);

/* Allocates blocks for a file to fulfil write request.
   Maps all unmapped but prepared pages from the list.
   Updates metadata with newly allocated blocknumbers as needed */
int reiserfs_allocate_blocks_for_region(
				struct reiserfs_transaction_handle *th,
				struct inode *inode, /* Inode we work with */
				loff_t pos, /* Writing position */
				int num_pages, /* number of pages write going
						  to touch */
				int write_bytes, /* amount of bytes to write */
				struct page **prepared_pages, /* array of
							         prepared pages
							       */
				int blocks_to_allocate /* Amount of blocks we
							  need to allocate to
							  fit the data into file
							 */
				)
{
    struct cpu_key key; // cpu key of item that we are going to deal with
    struct item_head *ih; // pointer to item head that we are going to deal with
    struct buffer_head *bh; // Buffer head that contains items that we are going to deal with
    __u32 * item; // pointer to item we are going to deal with
    INITIALIZE_PATH(path); // path to item, that we are going to deal with.
    b_blocknr_t *allocated_blocks; // Pointer to a place where allocated blocknumbers would be stored.
    reiserfs_blocknr_hint_t hint; // hint structure for block allocator.
    size_t res; // return value of various functions that we call.
    int curr_block; // current block used to keep track of unmapped blocks.
    int i; // loop counter
    int itempos; // position in item
    unsigned int from = (pos & (PAGE_CACHE_SIZE - 1)); // writing position in
						       // first page
    unsigned int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1; /* last modified byte offset in last page */
    __u64 hole_size ; // amount of blocks for a file hole, if it needed to be created.
    int modifying_this_item = 0; // Flag for items traversal code to keep track
				 // of the fact that we already prepared
				 // current block for journal
    int will_prealloc = 0;

    RFALSE(!blocks_to_allocate, "green-9004: tried to allocate zero blocks?");

    /* only preallocate if this is a small write */
    if (REISERFS_I(inode)->i_prealloc_count ||
       (!(write_bytes & (inode->i_sb->s_blocksize -1)) &&
        blocks_to_allocate <
        REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize))
        will_prealloc = REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize;

    allocated_blocks = kmalloc((blocks_to_allocate + will_prealloc) *
    					sizeof(b_blocknr_t), GFP_NOFS);

    /* First we compose a key to point at the writing position, we want to do
       that outside of any locking region. */
    make_cpu_key (&key, inode, pos+1, TYPE_ANY, 3/*key length*/);

    /* If we came here, it means we absolutely need to open a transaction,
       since we need to allocate some blocks */
    reiserfs_write_lock(inode->i_sb); // Journaling stuff and we need that.
    journal_begin(th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3 + 1); // Wish I know if this number enough
    reiserfs_update_inode_transaction(inode) ;

    /* Look for the in-tree position of our write, need path for block allocator */
    res = search_for_position_by_key(inode->i_sb, &key, &path);
    if ( res == IO_ERROR ) {
	res = -EIO;
	goto error_exit;
    }
   
    /* Allocate blocks */
    /* First fill in "hint" structure for block allocator */
    hint.th = th; // transaction handle.
    hint.path = &path; // Path, so that block allocator can determine packing locality or whatever it needs to determine.
    hint.inode = inode; // Inode is needed by block allocator too.
    hint.search_start = 0; // We have no hint on where to search free blocks for block allocator.
    hint.key = key.on_disk_key; // on disk key of file.
    hint.block = inode->i_blocks>>(inode->i_sb->s_blocksize_bits-9); // Number of disk blocks this file occupies already.
    hint.formatted_node = 0; // We are allocating blocks for unformatted node.
    hint.preallocate = will_prealloc;

    /* Call block allocator to allocate blocks */
    res = reiserfs_allocate_blocknrs(&hint, allocated_blocks, blocks_to_allocate, blocks_to_allocate);
    if ( res != CARRY_ON ) {
	if ( res == NO_DISK_SPACE ) {
	    /* We flush the transaction in case of no space. This way some
	       blocks might become free */
	    SB_JOURNAL(inode->i_sb)->j_must_wait = 1;
	    restart_transaction(th, inode, &path);

	    /* We might have scheduled, so search again */
	    res = search_for_position_by_key(inode->i_sb, &key, &path);
	    if ( res == IO_ERROR ) {
		res = -EIO;
		goto error_exit;
	    }

	    /* update changed info for hint structure. */
	    res = reiserfs_allocate_blocknrs(&hint, allocated_blocks, blocks_to_allocate, blocks_to_allocate);
	    if ( res != CARRY_ON ) {
		res = -ENOSPC; 
		pathrelse(&path);
//.........这里部分代码省略.........