thin-provisioning-tools/thin-provisioning/thin_pool.cc
2020-06-19 18:07:55 +08:00

445 lines
10 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 "base/math_utils.h"
#include "thin-provisioning/thin_pool.h"
#include <stdexcept>
using namespace base;
using namespace std;
using namespace persistent_data;
using namespace thin_provisioning;
//----------------------------------------------------------------
thin::thin(thin_dev_t dev, thin_pool &pool)
: dev_(dev),
pool_(pool),
details_(pool.get_transaction_id(), pool.get_time()),
open_count_(1),
changed_(true)
{
}
thin::thin(thin_dev_t dev, thin_pool &pool,
device_tree_detail::device_details const &details)
: dev_(dev),
pool_(pool),
details_(details),
open_count_(1),
changed_(false)
{
}
thin_dev_t
thin::get_dev_t() const
{
return dev_;
}
thin::maybe_address
thin::lookup(block_address thin_block)
{
uint64_t key[2] = {dev_, thin_block};
mapping_tree::maybe_value m = pool_.md_->mappings_->lookup(key);
if (!m)
return thin::maybe_address();
lookup_result r;
r.block_ = m->block_;
r.shared_ = m->time_ < details_.snapshotted_time_;
return r;
}
bool
thin::insert(block_address thin_block, block_address data_block)
{
uint64_t key[2] = {dev_, thin_block};
++details_.mapped_blocks_;
changed_ = true;
mapping_tree_detail::block_time bt;
bt.block_ = data_block;
bt.time_ = pool_.get_time();
return pool_.md_->mappings_->insert(key, bt);
}
void
thin::remove(block_address thin_block)
{
uint64_t key[2] = {dev_, thin_block};
pool_.md_->mappings_->remove(key);
--details_.mapped_blocks_;
changed_ = true;
}
void
thin::set_snapshot_time(uint32_t time)
{
details_.snapshotted_time_ = time;
changed_ = true;
}
block_address
thin::get_mapped_blocks() const
{
return details_.mapped_blocks_;
}
void
thin::set_mapped_blocks(block_address count)
{
details_.mapped_blocks_ = count;
changed_ = true;
}
//--------------------------------
thin_pool::thin_pool(block_manager::ptr bm)
{
md_ = metadata::ptr(new metadata(bm, true));
}
thin_pool::thin_pool(block_manager::ptr bm,
sector_t data_block_size,
block_address nr_data_blocks)
{
md_ = metadata::ptr(new metadata(bm,
metadata::CREATE,
data_block_size,
nr_data_blocks));
md_->commit();
}
thin_pool::~thin_pool()
{
}
void
thin_pool::create_thin(thin_dev_t dev)
{
uint64_t key[1] = {dev};
if (device_exists(dev))
throw std::runtime_error("device already exists");
single_mapping_tree::ptr new_tree(new single_mapping_tree(*md_->tm_,
mapping_tree_detail::block_time_ref_counter(md_->data_sm_)));
md_->mappings_top_level_->insert(key, new_tree->get_root());
md_->mappings_->set_root(md_->mappings_top_level_->get_root()); // FIXME: ugly
thin::ptr r = create_device(dev);
close_device(r);
}
void
thin_pool::create_snap(thin_dev_t dev, thin_dev_t origin)
{
uint64_t snap_key[1] = {dev};
uint64_t origin_key[1] = {origin};
if (device_exists(dev))
throw std::runtime_error("device already exists");
// find the mapping tree of the origin
dev_tree::maybe_value mtree_root = md_->mappings_top_level_->lookup(origin_key);
if (!mtree_root)
throw std::runtime_error("unknown origin");
single_mapping_tree otree(*md_->tm_, *mtree_root,
mapping_tree_detail::block_time_ref_counter(md_->data_sm_));
// clone the origin
single_mapping_tree::ptr clone(otree.clone());
md_->mappings_top_level_->insert(snap_key, clone->get_root());
md_->mappings_->set_root(md_->mappings_top_level_->get_root()); // FIXME: ugly
md_->sb_.time_++;
// create details for the snapshot
thin::ptr s = create_device(dev);
set_snapshot_details(s, origin);
close_device(s);
}
void
thin_pool::del(thin_dev_t dev)
{
uint64_t key[1] = {dev};
thin::ptr td = open_device(dev);
if (td->open_count_ > 1) {
close_device(td);
throw std::runtime_error("device busy");
}
thin_devices_.erase(dev);
dev_tree::maybe_value mtree_root = md_->mappings_top_level_->lookup(key);
if (!device_exists(dev) || !mtree_root)
throw std::runtime_error("unknown device");
// TODO: trigger subtree deletion from the mtree_ref_counter,
// like the kenrel subtree_dec() does.
single_mapping_tree mtree(*md_->tm_, *mtree_root,
mapping_tree_detail::block_time_ref_counter(md_->data_sm_));
mtree.destroy();
md_->details_->remove(key);
md_->mappings_top_level_->remove(key);
md_->mappings_->set_root(md_->mappings_top_level_->get_root()); // FIXME: ugly
}
void
thin_pool::commit()
{
write_changed_details();
md_->commit();
}
void
thin_pool::set_transaction_id(uint64_t id)
{
md_->sb_.trans_id_ = id;
}
uint64_t
thin_pool::get_transaction_id() const
{
return md_->sb_.trans_id_;
}
void
thin_pool::reserve_metadata_snap()
{
if (md_->sb_.metadata_snap_)
throw std::runtime_error("pool metadata snapshot already exists.");
commit();
md_->metadata_sm_->inc(superblock_detail::SUPERBLOCK_LOCATION);
transaction_manager::write_ref wr = md_->tm_->shadow(
superblock_detail::SUPERBLOCK_LOCATION,
superblock_validator()).first;
superblock_detail::superblock sb;
superblock_detail::superblock_disk *sbd = reinterpret_cast<superblock_detail::superblock_disk *>(wr.data());
superblock_detail::superblock_traits::unpack(*sbd, sb);
memset(sb.data_space_map_root_, 0, superblock_detail::SPACE_MAP_ROOT_SIZE);
memset(sb.metadata_space_map_root_, 0, superblock_detail::SPACE_MAP_ROOT_SIZE);
md_->metadata_sm_->inc(sb.data_mapping_root_);
md_->metadata_sm_->inc(sb.device_details_root_);
superblock_detail::superblock_traits::pack(sb, *sbd);
md_->sb_.metadata_snap_ = wr.get_location();
}
void
thin_pool::release_metadata_snap()
{
if (!md_->sb_.metadata_snap_)
throw std::runtime_error("No pool metadata snapshot found");
superblock_detail::superblock sb = read_superblock(md_->tm_->get_bm(),
md_->sb_.metadata_snap_);
device_tree dtree(*md_->tm_, sb.device_details_root_,
device_tree_detail::device_details_traits::ref_counter());
dtree.destroy();
mapping_tree mtree(*md_->tm_, sb.data_mapping_root_,
mapping_tree_detail::block_traits::ref_counter(md_->tm_->get_sm()));
mtree.destroy();
md_->metadata_sm_->dec(md_->sb_.metadata_snap_);
md_->sb_.metadata_snap_ = 0;
}
block_address
thin_pool::get_metadata_snap() const
{
return md_->sb_.metadata_snap_;
}
block_address
thin_pool::alloc_data_block()
{
space_map::maybe_block mb = md_->data_sm_->new_block();
if (!mb)
throw runtime_error("couldn't allocate new block");
return *mb;
}
void
thin_pool::free_data_block(block_address b)
{
md_->data_sm_->dec(b);
}
block_address
thin_pool::get_nr_free_data_blocks() const
{
return md_->data_sm_->get_nr_free();
}
thin_provisioning::sector_t
thin_pool::get_data_block_size() const
{
return md_->sb_.data_block_size_;
}
block_address
thin_pool::get_data_dev_size() const
{
return md_->data_sm_->get_nr_blocks();
}
uint32_t
thin_pool::get_time() const
{
return md_->sb_.time_;
}
thin::ptr
thin_pool::open_thin(thin_dev_t dev)
{
return open_device(dev);
}
void
thin_pool::close_thin(thin::ptr td)
{
close_device(td);
}
bool
thin_pool::device_exists(thin_dev_t dev) const
{
uint64_t key[1] = {dev};
return !!md_->details_->lookup(key);
}
thin::ptr
thin_pool::create_device(thin_dev_t dev)
{
device_map::iterator it = thin_devices_.find(dev);
if (it != thin_devices_.end())
throw std::runtime_error("device already exists");
thin::ptr td(new thin(dev, *this));
thin_devices_[dev] = td;
return td;
}
thin::ptr
thin_pool::open_device(thin_dev_t dev)
{
device_map::iterator it = thin_devices_.find(dev);
if (it != thin_devices_.end()) {
thin::ptr td = it->second;
td->open_count_++;
return td;
}
uint64_t key[1] = {dev};
device_tree::maybe_value details = md_->details_->lookup(key);
if (!details)
throw std::runtime_error("no such device");
thin::ptr td(new thin(dev, *this, *details));
thin_devices_[dev] = td;
return td;
}
void
thin_pool::close_device(thin::ptr td)
{
td->open_count_--;
}
void
thin_pool::set_snapshot_details(thin::ptr snap, thin_dev_t origin)
{
thin::ptr o = open_device(origin);
o->set_snapshot_time(md_->sb_.time_);
snap->set_snapshot_time(md_->sb_.time_);
snap->set_mapped_blocks(o->get_mapped_blocks());
close_device(o);
}
void
thin_pool::write_changed_details()
{
for (auto it = thin_devices_.cbegin(); it != thin_devices_.cend(); ) {
uint64_t key[1] = {it->first};
thin::ptr td = it->second;
if (td->changed_) {
md_->details_->insert(key, td->details_);
td->changed_ = false;
}
if (!td->open_count_)
it = thin_devices_.erase(it);
else
++it;
}
}
//----------------------------------------------------------------
void
thin_provisioning::process_read(thin::ptr td, thin_pool::ptr tp,
sector_t offset)
{
block_address blocknr = base::div_up<sector_t>(offset, tp->get_data_block_size());
td->lookup(blocknr);
}
void
thin_provisioning::process_write(thin::ptr td, thin_pool::ptr tp,
sector_t offset)
{
block_address blocknr = base::div_up<sector_t>(offset, tp->get_data_block_size());
thin::maybe_address result = td->lookup(blocknr);
if (!!result && !result->shared_)
return;
// TODO: handle out-of-space errors
block_address data_block = tp->alloc_data_block();
td->insert(blocknr, data_block);
}
void
thin_provisioning::process_discard(thin::ptr td, thin_pool::ptr tp,
sector_t offset)
{
block_address blocknr = base::div_up<sector_t>(offset, tp->get_data_block_size());
thin::maybe_address result = td->lookup(blocknr);
if (!result)
return;
td->remove(blocknr);
if (!result->shared_)
tp->free_data_block(result->block_);
}
//----------------------------------------------------------------