thin-provisioning-tools/thin-provisioning/metadata.cc
2018-04-17 14:00:44 +01:00

173 lines
5.7 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/>.
#include "thin-provisioning/device_tree.h"
#include "thin-provisioning/metadata.h"
#include "persistent-data/file_utils.h"
#include "persistent-data/math_utils.h"
#include "persistent-data/space-maps/core.h"
#include "persistent-data/space-maps/disk.h"
#include <linux/fs.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
using namespace base;
using namespace thin_provisioning;
#define METADATA_VERSION 2
//----------------------------------------------------------------
namespace {
using namespace superblock_detail;
void
copy_space_maps(space_map::ptr lhs, space_map::ptr rhs) {
for (block_address b = 0; b < rhs->get_nr_blocks(); b++) {
uint32_t count = rhs->get_count(b);
if (count > 0)
lhs->set_count(b, rhs->get_count(b));
}
}
}
//----------------------------------------------------------------
metadata::metadata(block_manager<>::ptr bm, open_type ot,
sector_t data_block_size,
block_address nr_data_blocks)
{
switch (ot) {
case OPEN:
tm_ = open_tm(bm, SUPERBLOCK_LOCATION);
sb_ = read_superblock(tm_->get_bm());
if (sb_.version_ < METADATA_VERSION)
throw runtime_error("unknown metadata version");
metadata_sm_ = open_metadata_sm(*tm_, &sb_.metadata_space_map_root_);
tm_->set_sm(metadata_sm_);
data_sm_ = open_disk_sm(*tm_, static_cast<void *>(&sb_.data_space_map_root_));
details_ = device_tree::ptr(new device_tree(*tm_, sb_.device_details_root_,
device_tree_detail::device_details_traits::ref_counter()));
mappings_top_level_ = dev_tree::ptr(new dev_tree(*tm_, sb_.data_mapping_root_,
mapping_tree_detail::mtree_ref_counter(tm_)));
mappings_ = mapping_tree::ptr(new mapping_tree(*tm_, sb_.data_mapping_root_,
mapping_tree_detail::block_time_ref_counter(data_sm_)));
break;
case CREATE:
tm_ = open_tm(bm, SUPERBLOCK_LOCATION);
space_map::ptr core = tm_->get_sm();
metadata_sm_ = create_metadata_sm(*tm_, tm_->get_bm()->get_nr_blocks());
copy_space_maps(metadata_sm_, core);
tm_->set_sm(metadata_sm_);
data_sm_ = create_disk_sm(*tm_, nr_data_blocks);
details_ = device_tree::ptr(new device_tree(*tm_,
device_tree_detail::device_details_traits::ref_counter()));
mappings_ = mapping_tree::ptr(new mapping_tree(*tm_,
mapping_tree_detail::block_time_ref_counter(data_sm_)));
mappings_top_level_ = dev_tree::ptr(new dev_tree(*tm_, mappings_->get_root(),
mapping_tree_detail::mtree_ref_counter(tm_)));
::memset(&sb_, 0, sizeof(sb_));
sb_.magic_ = SUPERBLOCK_MAGIC;
sb_.version_ = METADATA_VERSION;
sb_.data_mapping_root_ = mappings_->get_root();
sb_.device_details_root_ = details_->get_root();
sb_.data_block_size_ = data_block_size;
sb_.metadata_block_size_ = MD_BLOCK_SIZE >> SECTOR_SHIFT;
sb_.metadata_nr_blocks_ = metadata_sm_->get_nr_blocks();
break;
}
}
metadata::metadata(block_manager<>::ptr bm, bool read_space_maps)
{
tm_ = open_tm(bm, SUPERBLOCK_LOCATION);
sb_ = read_superblock(tm_->get_bm(), SUPERBLOCK_LOCATION);
if (read_space_maps)
open_space_maps();
open_btrees();
}
metadata::metadata(block_manager<>::ptr bm,
boost::optional<block_address> metadata_snap)
{
tm_ = open_tm(bm, SUPERBLOCK_LOCATION);
superblock_detail::superblock actual_sb = read_superblock(bm, SUPERBLOCK_LOCATION);
if (!actual_sb.metadata_snap_)
throw runtime_error("no current metadata snap");
if (metadata_snap && *metadata_snap != actual_sb.metadata_snap_)
throw runtime_error("metadata snapshot does not match that in superblock");
sb_ = read_superblock(bm, actual_sb.metadata_snap_);
// metadata snaps don't record the space maps
open_btrees();
}
void
metadata::commit()
{
sb_.data_mapping_root_ = mappings_->get_root();
sb_.device_details_root_ = details_->get_root();
data_sm_->commit();
data_sm_->copy_root(&sb_.data_space_map_root_, sizeof(sb_.data_space_map_root_));
metadata_sm_->commit();
metadata_sm_->copy_root(&sb_.metadata_space_map_root_, sizeof(sb_.metadata_space_map_root_));
write_ref superblock = tm_->get_bm()->superblock_zero(SUPERBLOCK_LOCATION, superblock_validator());
superblock_disk *disk = reinterpret_cast<superblock_disk *>(superblock.data());
superblock_traits::pack(sb_, *disk);
}
void metadata::open_space_maps()
{
metadata_sm_ = open_metadata_sm(*tm_, &sb_.metadata_space_map_root_);
tm_->set_sm(metadata_sm_);
data_sm_ = open_disk_sm(*tm_, static_cast<void *>(&sb_.data_space_map_root_));
}
void metadata::open_btrees()
{
details_ = device_tree::ptr(new device_tree(*tm_, sb_.device_details_root_,
device_tree_detail::device_details_traits::ref_counter()));
mappings_top_level_ = dev_tree::ptr(new dev_tree(*tm_, sb_.data_mapping_root_,
mapping_tree_detail::mtree_ref_counter(tm_)));
mappings_ = mapping_tree::ptr(new mapping_tree(*tm_, sb_.data_mapping_root_,
mapping_tree_detail::block_time_ref_counter(data_sm_)));
}
//----------------------------------------------------------------