thin-provisioning-tools/caching/metadata.cc

157 lines
3.4 KiB
C++

#include "caching/metadata.h"
#include "caching/superblock.h"
#include "persistent-data/space-maps/core.h"
using namespace caching;
namespace pd = persistent_data;
//----------------------------------------------------------------
namespace {
unsigned const METADATA_CACHE_SIZE = 1024;
// FIXME: duplication
transaction_manager::ptr
open_tm(block_manager<>::ptr bm) {
auto nr_blocks = bm->get_nr_blocks();
if (!nr_blocks)
throw runtime_error("Metadata is not large enough for superblock.");
space_map::ptr sm(new core_map(nr_blocks));
sm->inc(SUPERBLOCK_LOCATION);
transaction_manager::ptr tm(new transaction_manager(bm, sm));
return tm;
}
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, unsigned metadata_version)
{
switch (ot) {
case CREATE:
create_metadata(bm, metadata_version);
break;
default:
throw runtime_error("unhandled open_type");
}
}
metadata::metadata(block_manager<>::ptr bm)
{
open_metadata(bm);
}
void
metadata::commit(bool clean_shutdown)
{
commit_space_map();
commit_mappings();
commit_hints();
commit_discard_bits();
commit_superblock(clean_shutdown);
}
void
metadata::setup_hint_array(size_t width)
{
if (width > 0)
hints_ = hint_array::ptr(
new hint_array(*tm_, width));
}
void
metadata::create_metadata(block_manager<>::ptr bm, unsigned metadata_version)
{
tm_ = open_tm(bm);
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_);
mappings_ = mapping_array::ptr(new mapping_array(*tm_, mapping_array::ref_counter()));
// We can't instantiate the hint array yet, since we don't know the
// hint width.
discard_bits_ = pd::bitset::ptr(new pd::bitset(*tm_));
if (metadata_version >= 2)
dirty_bits_ = pd::bitset::ptr(new pd::bitset(*tm_));
}
void
metadata::open_metadata(block_manager<>::ptr bm)
{
tm_ = open_tm(bm);
sb_ = read_superblock(tm_->get_bm());
mappings_ = mapping_array::ptr(
new mapping_array(*tm_,
mapping_array::ref_counter(),
sb_.mapping_root,
sb_.cache_blocks));
if (sb_.hint_root)
hints_ = hint_array::ptr(
new hint_array(*tm_, sb_.policy_hint_size,
sb_.hint_root, sb_.cache_blocks));
if (sb_.discard_root)
discard_bits_ = pd::bitset::ptr(
new pd::bitset(*tm_, sb_.discard_root, sb_.discard_nr_blocks));
if (sb_.version >= 2)
dirty_bits_ = pd::bitset::ptr(
new pd::bitset(*tm_, *sb_.dirty_root, sb_.cache_blocks));
}
void
metadata::commit_space_map()
{
metadata_sm_->commit();
metadata_sm_->copy_root(&sb_.metadata_space_map_root, sizeof(sb_.metadata_space_map_root));
}
void
metadata::commit_mappings()
{
sb_.mapping_root = mappings_->get_root();
}
void
metadata::commit_hints()
{
sb_.hint_root = hints_->get_root();
}
void
metadata::commit_discard_bits()
{
sb_.discard_root = discard_bits_->get_root();
}
void
metadata::commit_superblock(bool clean_shutdown)
{
if (clean_shutdown)
sb_.flags.set_flag(superblock_flags::CLEAN_SHUTDOWN);
write_superblock(tm_->get_bm(), sb_);
sb_.flags.clear_flag(superblock_flags::CLEAN_SHUTDOWN);
}
//----------------------------------------------------------------