thin-provisioning-tools/metadata.cc
2011-06-27 10:45:30 +01:00

218 lines
4.0 KiB
C++

#include "metadata.h"
#include <stdexcept>
using namespace persistent_data;
using namespace multisnap;
//----------------------------------------------------------------
namespace {
typedef uint8_t __le8;
typedef uint8_t __u8;
typedef uint32_t __le32;
typedef uint64_t __le64;
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;
unsigned const SPACE_MAP_ROOT_SIZE = 128;
struct multisnap_super_block {
__le32 csum_;
__le32 flags_;
__le64 blocknr_; /* this block number, dm_block_t */
__u8 uuid_[16];
__le64 magic_;
__le32 version_;
__le32 time_;
__le64 trans_id_;
/* root for userspace's transaction (for migration and friends) */
__le64 held_root_;
__u8 data_space_map_root_[SPACE_MAP_ROOT_SIZE];
__u8 metadata_space_map_root_[SPACE_MAP_ROOT_SIZE];
/* 2 level btree mapping (dev_id, (dev block, time)) -> data block */
__le64 data_mapping_root_;
/* device detail root mapping dev_id -> device_details */
__le64 device_details_root_;
__le32 data_block_size_; /* in 512-byte sectors */
__le32 metadata_block_size_; /* in 512-byte sectors */
__le64 metadata_nr_blocks_;
__le32 compat_flags_;
__le32 incompat_flags_;
} __attribute__ ((packed));
struct device_details {
__le64 dev_size_;
__le64 mapped_blocks_;
__le64 transaction_id_; /* when created */
__le32 creation_time_;
__le32 snapshotted_time_;
} __attribute__ ((packed));
}
//----------------------------------------------------------------
metadata::thin::maybe_address
metadata::thin::lookup(block_address thin_block)
{
uint64_t key[2] = {dev_, thin_block};
return metadata_->mappings_.lookup(key);
}
void
metadata::thin::insert(block_address thin_block, block_address data_block)
{
uint64_t key[2] = {dev_, thin_block};
return metadata_->mappings_.insert(key, data_block);
}
void
metadata::thin::remove(block_address thin_block)
{
uint64_t key[2] = {dev_, thin_block};
metadata_->mappings_.remove(key);
}
#if 0
//--------------------------------
metadata::metadata(std::string const &metadata_dev,
sector_t data_block_size,
block_address nr_data_blocks)
{
}
metadata::~metadata()
{
}
void
metadata::commit()
{
}
#endif
void
metadata::create_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_));
mappings_top_level_.insert(key, new_tree->get_root());
mappings_.set_root(mappings_top_level_.get_root()); // FIXME: ugly
}
void
metadata::create_snap(dev_t dev, dev_t origin)
{
uint64_t snap_key[1] = {dev};
uint64_t origin_key[1] = {origin};
auto mtree_root = mappings_top_level_.lookup(origin_key);
if (!mtree_root)
throw std::runtime_error("unknown origin");
single_mapping_tree otree(tm_, *mtree_root);
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
time_++;
auto o = open(origin);
auto s = open(dev);
o->set_snapshot_time(time_);
s->set_snapshot_time(time_);
s->set_mapped_blocks(o->get_mapped_blocks());
}
void
metadata::del(dev_t dev)
{
uint64_t key[1] = {dev};
mappings_top_level_.remove(key);
}
#if 0
void
metadata::set_transaction_id(uint64_t id)
{
}
uint64_t
metadata::get_transaction_id() const
{
}
block_address
metadata::get_held_root() const
{
}
thin_ptr
metadata::open_device(dev_t)
{
}
block_address
metadata::alloc_data_block()
{
}
void
metadata::free_data_block(block_address b)
{
}
block_address
metadata::get_nr_free_data_blocks() const
{
}
sector_t
metadata::get_data_block_size() const
{
}
block_address
metadata::get_data_dev_size() const
{
}
#endif
bool
metadata::device_exists(dev_t dev) const
{
uint64_t key[1] = {dev};
auto mval = details_.lookup(key);
return mval;
}
//----------------------------------------------------------------