thin-provisioning-tools/caching/superblock.cc
2013-08-16 13:39:12 +01:00

178 lines
5.6 KiB
C++

#include "caching/superblock.h"
using namespace caching;
using namespace superblock_detail;
//----------------------------------------------------------------
void
superblock_traits::unpack(superblock_disk const &disk, superblock &core)
{
core.csum = to_cpu<uint32_t>(disk.csum);
core.flags = to_cpu<uint32_t>(disk.flags);
core.blocknr = to_cpu<uint64_t>(disk.blocknr);
::memcpy(core.uuid, disk.uuid, sizeof(core.uuid));
core.magic = to_cpu<uint64_t>(disk.magic);
core.version = to_cpu<uint32_t>(disk.version);
::memcpy(core.policy_name, disk.policy_name, sizeof(core.policy_name));
for (unsigned i = 0; i < CACHE_POLICY_VERSION_SIZE; i++)
core.policy_version[i] = to_cpu<uint32_t>(disk.policy_version[i]);
core.policy_hint_size = to_cpu<uint32_t>(disk.policy_hint_size);
::memcpy(core.metadata_space_map_root,
disk.metadata_space_map_root,
sizeof(core.metadata_space_map_root));
core.mapping_root = to_cpu<uint64_t>(disk.mapping_root);
core.hint_root = to_cpu<uint64_t>(disk.hint_root);
core.discard_root = to_cpu<uint64_t>(disk.discard_root);
core.discard_block_size = to_cpu<uint64_t>(disk.discard_block_size);
core.discard_nr_blocks = to_cpu<uint64_t>(disk.discard_nr_blocks);
core.data_block_size = to_cpu<uint32_t>(disk.data_block_size);
core.metadata_block_size = to_cpu<uint32_t>(disk.metadata_block_size);
core.cache_blocks = to_cpu<uint32_t>(disk.cache_blocks);
core.compat_flags = to_cpu<uint32_t>(disk.compat_flags);
core.compat_ro_flags = to_cpu<uint32_t>(disk.compat_ro_flags);
core.incompat_flags = to_cpu<uint32_t>(disk.incompat_flags);
core.read_hits = to_cpu<uint32_t>(disk.read_hits);
core.read_misses = to_cpu<uint32_t>(disk.read_misses);
core.write_hits = to_cpu<uint32_t>(disk.write_hits);
core.write_misses = to_cpu<uint32_t>(disk.write_misses);
}
void
superblock_traits::pack(superblock const &core, superblock_disk &disk)
{
disk.csum = to_disk<le32>(core.csum);
disk.flags = to_disk<le32>(core.flags);
disk.blocknr = to_disk<le64>(core.blocknr);
::memcpy(disk.uuid, core.uuid, sizeof(disk.uuid));
disk.magic = to_disk<le64>(core.magic);
disk.version = to_disk<le32>(core.version);
::memcpy(disk.policy_name, core.policy_name, sizeof(disk.policy_name));
for (unsigned i = 0; i < CACHE_POLICY_VERSION_SIZE; i++)
disk.policy_version[i] = to_disk<le32>(core.policy_version[i]);
disk.policy_hint_size = to_disk<le32>(core.policy_hint_size);
::memcpy(disk.metadata_space_map_root,
core.metadata_space_map_root,
sizeof(disk.metadata_space_map_root));
disk.mapping_root = to_disk<le64>(core.mapping_root);
disk.hint_root = to_disk<le64>(core.hint_root);
disk.discard_root = to_disk<le64>(core.discard_root);
disk.discard_block_size = to_disk<le64>(core.discard_block_size);
disk.discard_nr_blocks = to_disk<le64>(core.discard_nr_blocks);
disk.data_block_size = to_disk<le32>(core.data_block_size);
disk.metadata_block_size = to_disk<le32>(core.metadata_block_size);
disk.cache_blocks = to_disk<le32>(core.cache_blocks);
disk.compat_flags = to_disk<le32>(core.compat_flags);
disk.compat_ro_flags = to_disk<le32>(core.compat_ro_flags);
disk.incompat_flags = to_disk<le32>(core.incompat_flags);
disk.read_hits = to_disk<le32>(core.read_hits);
disk.read_misses = to_disk<le32>(core.read_misses);
disk.write_hits = to_disk<le32>(core.write_hits);
disk.write_misses = to_disk<le32>(core.write_misses);
}
//--------------------------------
superblock_corruption::superblock_corruption(std::string const &desc)
: desc_(desc)
{
}
void
superblock_corruption::visit(damage_visitor &v) const
{
v.visit(*this);
}
//--------------------------------
namespace {
using namespace persistent_data;
using namespace superblock_detail;
uint32_t const VERSION = 1;
unsigned const SECTOR_TO_BLOCK_SHIFT = 3;
uint32_t const SUPERBLOCK_CSUM_SEED = 9031977;
struct sb_validator : public block_manager<>::validator {
virtual void check(buffer<> const &b, block_address location) const {
superblock_disk const *sbd = reinterpret_cast<superblock_disk const *>(&b);
crc32c sum(SUPERBLOCK_CSUM_SEED);
sum.append(&sbd->flags, MD_BLOCK_SIZE - sizeof(uint32_t));
if (sum.get_sum() != to_cpu<uint32_t>(sbd->csum))
throw checksum_error("bad checksum in superblock");
}
virtual void prepare(buffer<> &b, block_address location) const {
superblock_disk *sbd = reinterpret_cast<superblock_disk *>(&b);
crc32c sum(SUPERBLOCK_CSUM_SEED);
sum.append(&sbd->flags, MD_BLOCK_SIZE - sizeof(uint32_t));
sbd->csum = to_disk<base::le32>(sum.get_sum());
}
};
}
persistent_data::block_manager<>::validator::ptr
caching::superblock_validator()
{
return block_manager<>::validator::ptr(new sb_validator);
}
//--------------------------------
superblock_detail::superblock
caching::read_superblock(persistent_data::block_manager<>::ptr bm,
persistent_data::block_address location)
{
using namespace superblock_detail;
superblock sb;
block_manager<>::read_ref r = bm->read_lock(location, superblock_validator());
superblock_disk const *sbd = reinterpret_cast<superblock_disk const *>(&r.data());
superblock_traits::unpack(*sbd, sb);
return sb;
}
superblock_detail::superblock
caching::read_superblock(persistent_data::block_manager<>::ptr bm)
{
return read_superblock(bm, SUPERBLOCK_LOCATION);
}
void
caching::check_superblock(persistent_data::block_manager<>::ptr bm,
superblock_detail::damage_visitor &visitor)
{
using namespace superblock_detail;
try {
bm->read_lock(SUPERBLOCK_LOCATION, superblock_validator());
} catch (std::exception const &e) {
visitor.visit(superblock_corruption(e.what()));
}
}
//----------------------------------------------------------------