thin-provisioning-tools/metadata.cc
2011-08-25 16:13:54 +01:00

394 lines
10 KiB
C++

#include "metadata.h"
#include "btree_validator.h"
#include "core_map.h"
#include <stdexcept>
#include <sstream>
#include <iostream>
#include <set>
#include <map>
using namespace std;
using namespace persistent_data;
using namespace thin_provisioning;
//----------------------------------------------------------------
namespace {
uint32_t const SUPERBLOCK_MAGIC = 27022010;
block_address const SUPERBLOCK_LOCATION = 0;
uint32_t const VERSION = 1;
unsigned const METADATA_CACHE_SIZE = 1024;
unsigned const SECTOR_TO_BLOCK_SHIFT = 3;
// FIXME: get the file size
unsigned const NR_BLOCKS = 1024;
transaction_manager<4096>::ptr
open_tm(string const &dev_path) {
block_manager<4096>::ptr bm(new block_manager<4096>(dev_path, NR_BLOCKS));
space_map::ptr sm(new core_map(NR_BLOCKS));
transaction_manager<4096>::ptr tm(new transaction_manager<4096>(bm, sm));
return tm;
}
superblock read_superblock(block_manager<4096>::ptr bm) {
superblock sb;
block_manager<4096>::read_ref r = bm->read_lock(SUPERBLOCK_LOCATION);
superblock_disk const *sbd = reinterpret_cast<superblock_disk const *>(&r.data());
superblock_traits::unpack(*sbd, sb);
return sb;
}
// As well as the standard btree checks, we build up a set of what
// devices having mappings defined, which can later be cross
// referenced with the details tree. A separate block_counter is
// used to later verify the data space map.
class mapping_validator : public btree_validator<2, block_traits, MD_BLOCK_SIZE> {
public:
typedef boost::shared_ptr<mapping_validator> ptr;
mapping_validator(block_counter &metadata_counter, block_counter &data_counter)
: btree_validator<2, block_traits, MD_BLOCK_SIZE>(metadata_counter),
data_counter_(data_counter) {
}
void visit_internal_leaf(unsigned level, bool is_root,
btree_detail::node_ref<uint64_traits, MD_BLOCK_SIZE> const &n) {
btree_validator<2, block_traits, MD_BLOCK_SIZE>::visit_internal_leaf(level, is_root, n);
for (unsigned i = 0; i < n.get_nr_entries(); i++)
devices_.insert(n.key_at(i));
}
void visit_leaf(unsigned level, bool is_root,
btree_detail::node_ref<block_traits, MD_BLOCK_SIZE> const &n) {
btree_validator<2, block_traits, MD_BLOCK_SIZE>::visit_leaf(level, is_root, n);
for (unsigned i = 0; i < n.get_nr_entries(); i++)
data_counter_.inc(n.value_at(i).block_);
}
set<uint64_t> const &get_devices() const {
return devices_;
}
private:
block_counter &data_counter_;
set<uint64_t> devices_;
};
class details_validator : public btree_validator<1, device_details_traits, MD_BLOCK_SIZE> {
public:
typedef boost::shared_ptr<details_validator> ptr;
details_validator(block_counter &counter)
: btree_validator<1, device_details_traits, MD_BLOCK_SIZE>(counter) {
}
void visit_leaf(unsigned level, bool is_root,
btree_detail::node_ref<device_details_traits, MD_BLOCK_SIZE> const &n) {
btree_validator<1, device_details_traits, MD_BLOCK_SIZE>::visit_leaf(level, is_root, n);
for (unsigned i = 0; i < n.get_nr_entries(); i++)
devices_.insert(n.key_at(i));
}
set<uint64_t> const &get_devices() const {
return devices_;
}
private:
set<uint64_t> devices_;
};
}
//----------------------------------------------------------------
thin::thin(thin_dev_t dev, metadata *metadata)
: dev_(dev),
metadata_(metadata)
{
}
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};
return metadata_->mappings_.lookup(key);
}
void
thin::insert(block_address thin_block, block_address data_block)
{
uint64_t key[2] = {dev_, thin_block};
block_time bt;
bt.block_ = data_block;
bt.time_ = 0; // FIXME: use current time.
return metadata_->mappings_.insert(key, bt);
}
void
thin::remove(block_address thin_block)
{
uint64_t key[2] = {dev_, thin_block};
metadata_->mappings_.remove(key);
}
void
thin::set_snapshot_time(uint32_t time)
{
uint64_t key[1] = { dev_ };
optional<device_details> mdetail = metadata_->details_.lookup(key);
if (!mdetail)
throw runtime_error("no such device");
mdetail->snapshotted_time_ = time;
metadata_->details_.insert(key, *mdetail);
}
block_address
thin::get_mapped_blocks() const
{
uint64_t key[1] = { dev_ };
optional<device_details> mdetail = metadata_->details_.lookup(key);
if (!mdetail)
throw runtime_error("no such device");
return mdetail->mapped_blocks_;
}
void
thin::set_mapped_blocks(block_address count)
{
uint64_t key[1] = { dev_ };
optional<device_details> mdetail = metadata_->details_.lookup(key);
if (!mdetail)
throw runtime_error("no such device");
mdetail->mapped_blocks_ = count;
metadata_->details_.insert(key, *mdetail);
}
//--------------------------------
metadata::metadata(std::string const &dev_path)
: tm_(open_tm(dev_path)),
sb_(read_superblock(tm_->get_bm())),
metadata_sm_(open_metadata_sm<MD_BLOCK_SIZE>(tm_, static_cast<void *>(&sb_.metadata_space_map_root_))),
data_sm_(open_disk_sm<MD_BLOCK_SIZE>(tm_, static_cast<void *>(&sb_.data_space_map_root_))),
details_(tm_, sb_.device_details_root_, device_details_traits::ref_counter()),
mappings_top_level_(tm_, sb_.data_mapping_root_, mtree_ref_counter<MD_BLOCK_SIZE>(tm_)),
mappings_(tm_, sb_.data_mapping_root_, block_time_ref_counter(data_sm_))
{
#if 0
::memset(&sb_, 0, sizeof(sb_));
sb_.data_mapping_root_ = mappings_.get_root();
sb_.device_details_root_ = details_.get_root();
sb_.metadata_block_size_ = MD_BLOCK_SIZE;
sb_.metadata_nr_blocks_ = tm_->get_bm()->get_nr_blocks();
#endif
}
metadata::~metadata()
{
}
void
metadata::commit()
{
sb_.data_mapping_root_ = mappings_.get_root();
sb_.device_details_root_ = details_.get_root();
write_ref superblock = tm_->get_bm()->superblock(SUPERBLOCK_LOCATION);
superblock_disk *disk = reinterpret_cast<superblock_disk *>(superblock.data());
superblock_traits::pack(sb_, *disk);
}
void
metadata::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(tm_, block_time_ref_counter(data_sm_)));
mappings_top_level_.insert(key, new_tree->get_root());
mappings_.set_root(mappings_top_level_.get_root()); // FIXME: ugly
}
void
metadata::create_snap(thin_dev_t dev, thin_dev_t origin)
{
uint64_t snap_key[1] = {dev};
uint64_t origin_key[1] = {origin};
optional<uint64_t> mtree_root = mappings_top_level_.lookup(origin_key);
if (!mtree_root)
throw std::runtime_error("unknown origin");
single_mapping_tree otree(tm_, *mtree_root,
block_time_ref_counter(data_sm_));
single_mapping_tree::ptr clone(otree.clone());
mappings_top_level_.insert(snap_key, clone->get_root());
mappings_.set_root(mappings_top_level_.get_root()); // FIXME: ugly
sb_.time_++;
thin::ptr o = open_thin(origin);
thin::ptr s = open_thin(dev);
o->set_snapshot_time(sb_.time_);
s->set_snapshot_time(sb_.time_);
s->set_mapped_blocks(o->get_mapped_blocks());
}
void
metadata::del(thin_dev_t dev)
{
uint64_t key[1] = {dev};
mappings_top_level_.remove(key);
}
void
metadata::set_transaction_id(uint64_t id)
{
sb_.trans_id_ = id;
}
uint64_t
metadata::get_transaction_id() const
{
return sb_.trans_id_;
}
block_address
metadata::get_held_root() const
{
return sb_.held_root_;
}
block_address
metadata::alloc_data_block()
{
return data_sm_->new_block();
}
void
metadata::free_data_block(block_address b)
{
data_sm_->dec(b);
}
block_address
metadata::get_nr_free_data_blocks() const
{
return data_sm_->get_nr_free();
}
sector_t
metadata::get_data_block_size() const
{
return sb_.data_block_size_;
}
block_address
metadata::get_data_dev_size() const
{
return data_sm_->get_nr_blocks();
}
thin::ptr
metadata::open_thin(thin_dev_t dev)
{
uint64_t key[1] = {dev};
optional<device_details> mdetails = details_.lookup(key);
if (!mdetails)
throw runtime_error("no such device");
thin *ptr = new thin(dev, this);
thin::ptr r(ptr);
return r;
}
bool
metadata::device_exists(thin_dev_t dev) const
{
uint64_t key[1] = {dev};
return details_.lookup(key);
}
namespace {
optional<error_set::ptr>
check_ref_counts(string const &desc, block_counter const &counts,
space_map::ptr sm) {
error_set::ptr errors(new error_set(desc));
bool bad = false;
for (block_address b = 0; b < sm->get_nr_blocks(); b++) {
uint32_t actual = sm->get_count(b);
uint32_t expected = counts.get_count(b);
if (actual != expected) {
ostringstream out;
out << b << ": was " << actual
<< ", expected " << expected;
errors->add_child(out.str());
bad = true;
}
}
return bad ? optional<error_set::ptr>(errors) : optional<error_set::ptr>();
}
}
boost::optional<error_set::ptr>
metadata::check()
{
error_set::ptr errors(new error_set("Errors in metadata"));
block_counter metadata_counter, data_counter;
mapping_validator::ptr mv(new mapping_validator(metadata_counter,
data_counter));
metadata_counter.inc(mappings_.get_root());
mappings_.visit(mv);
set<uint64_t> const &mapped_devs = mv->get_devices();
details_validator::ptr dv(new details_validator(metadata_counter));
metadata_counter.inc(details_.get_root());
details_.visit(dv);
set<uint64_t> const &details_devs = dv->get_devices();
for (set<uint64_t>::const_iterator it = mapped_devs.begin(); it != mapped_devs.end(); ++it)
if (details_devs.count(*it) == 0) {
ostringstream out;
out << "mapping exists for device " << *it
<< ", yet there is no entry in the details tree.";
throw runtime_error(out.str());
}
metadata_counter.inc(SUPERBLOCK_LOCATION);
metadata_sm_->check(metadata_counter);
data_sm_->check(metadata_counter);
errors->add_child(check_ref_counts("Errors in metadata block reference counts",
metadata_counter, metadata_sm_));
errors->add_child(check_ref_counts("Errors in data block reference counts",
data_counter, data_sm_));
return (errors->get_children().size() > 0) ?
optional<error_set::ptr>(errors) :
optional<error_set::ptr>();
}
//----------------------------------------------------------------