thin-provisioning-tools/thin-provisioning/metadata.h
Joe Thornber e801cc607b [block_manager] Hard code block size to 4k.
We're never going to use anything other than 4k, and by hard coding it we
avoid making block_manager a template.
2020-04-30 14:30:01 +01:00

105 lines
3.3 KiB
C++

// Copyright (C) 2011 Red Hat, Inc. All rights reserved.
//
// This file is part of the thin-provisioning-tools source.
//
// thin-provisioning-tools is free software: you can redistribute it
// and/or modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// thin-provisioning-tools is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with thin-provisioning-tools. If not, see
// <http://www.gnu.org/licenses/>.
#ifndef METADATA_LL_H
#define METADATA_LL_H
#include "base/endian_utils.h"
#include "persistent-data/block.h"
#include "persistent-data/data-structures/btree.h"
#include "persistent-data/space-maps/disk.h"
#include "persistent-data/transaction_manager.h"
#include "thin-provisioning/device_tree.h"
#include "thin-provisioning/mapping_tree.h"
#include "thin-provisioning/superblock.h"
//----------------------------------------------------------------
namespace thin_provisioning {
// FIXME: don't use namespaces in a header
using namespace base;
using namespace persistent_data;
typedef uint64_t sector_t;
typedef uint32_t thin_dev_t;
//------------------------------------------------
// FIXME: should these be in a sub-namespace?
typedef persistent_data::transaction_manager::ptr tm_ptr;
// The tools require different interfaces onto the metadata than
// the in kernel driver. This class gives access to the low-level
// implementation of metadata. Implement more specific interfaces
// on top of this.
struct metadata {
enum open_type {
CREATE,
OPEN
};
typedef block_manager::read_ref read_ref;
typedef block_manager::write_ref write_ref;
typedef boost::shared_ptr<metadata> ptr;
metadata(block_manager::ptr bm, open_type ot,
sector_t data_block_size = 128,
block_address nr_data_blocks = 0); // Only used if CREATE
// Ideally we'd like the metadata snap argument to be a
// boolean, and we'd read the snap location from the
// superblock. But the command line interface for some of
// the tools allows the user to pass in a block, which
// they've retrieved from the pool status. So we have to
// support 3 cases:
//
// i) Read superblock
// ii) Read the metadata snap as given in the superblock
// iii) Read the metadata snap given on command line, checking it matches superblock.
//
metadata(block_manager::ptr bm, bool read_space_maps = true); // (i)
metadata(block_manager::ptr,
boost::optional<block_address> metadata_snap); // (ii) and (iii)
// This is used by repair, when we rebuild the superblock
metadata(block_manager::ptr bm, superblock_detail::superblock const &sb);
void commit();
tm_ptr tm_;
superblock_detail::superblock sb_;
checked_space_map::ptr metadata_sm_;
checked_space_map::ptr data_sm_;
device_tree::ptr details_;
dev_tree::ptr mappings_top_level_;
mapping_tree::ptr mappings_;
private:
void open_space_maps();
void open_btrees();
};
}
//----------------------------------------------------------------
#endif