thin-provisioning-tools/caching/superblock.h

159 lines
3.5 KiB
C++

#ifndef CACHE_SUPERBLOCK_H
#define CACHE_SUPERBLOCK_H
#include "base/endian_utils.h"
#include "persistent-data/data-structures/btree.h"
#include <boost/optional.hpp>
#include <set>
//----------------------------------------------------------------
namespace caching {
typedef unsigned char __u8;
unsigned const MIN_METADATA_VERSION = 1;
unsigned const MAX_METADATA_VERSION = 2;
unsigned const SPACE_MAP_ROOT_SIZE = 128;
unsigned const CACHE_POLICY_NAME_SIZE = 16;
unsigned const CACHE_POLICY_VERSION_SIZE = 3;
block_address const SUPERBLOCK_LOCATION = 0;
class superblock_flags {
public:
enum flag {
CLEAN_SHUTDOWN,
NEEDS_CHECK
};
enum flag_bits {
CLEAN_SHUTDOWN_BIT = 0,
NEEDS_CHECK_BIT = 1,
};
superblock_flags();
superblock_flags(uint32_t bits);
void set_flag(flag f);
void clear_flag(flag f);
bool get_flag(flag f) const;
uint32_t encode() const;
uint32_t get_unhandled_flags() const;
private:
uint32_t unhandled_flags_;
std::set<flag> flags_;
};
struct superblock {
superblock();
uint32_t csum;
superblock_flags flags;
uint64_t blocknr;
__u8 uuid[16];
uint64_t magic;
uint32_t version;
__u8 policy_name[CACHE_POLICY_NAME_SIZE];
uint32_t policy_version[CACHE_POLICY_VERSION_SIZE];
uint32_t policy_hint_size;
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
uint64_t mapping_root;
uint64_t hint_root;
uint64_t discard_root;
uint64_t discard_block_size;
uint64_t discard_nr_blocks;
uint32_t data_block_size; /* in 512-byte sectors */
uint32_t metadata_block_size; /* in 512-byte sectors */
uint32_t cache_blocks;
uint32_t compat_flags;
uint32_t compat_ro_flags;
uint32_t incompat_flags;
uint32_t read_hits;
uint32_t read_misses;
uint32_t write_hits;
uint32_t write_misses;
boost::optional<uint64_t> dirty_root;
};
enum incompat_bits {
VARIABLE_HINT_SIZE_BIT = 0
};
//--------------------------------
namespace superblock_damage {
class damage_visitor;
class damage {
public:
damage(std::string const &desc)
: desc_(desc) {
}
virtual ~damage() {}
virtual void visit(damage_visitor &v) const = 0;
std::string const &get_desc() const {
return desc_;
}
private:
std::string desc_;
};
struct superblock_corrupt : public damage {
superblock_corrupt(std::string const &desc);
void visit(damage_visitor &v) const;
};
struct superblock_invalid : public damage {
superblock_invalid(std::string const &desc);
void visit(damage_visitor &v) const;
};
class damage_visitor {
public:
virtual ~damage_visitor() {}
void visit(damage const &d);
virtual void visit(superblock_corrupt const &d) = 0;
virtual void visit(superblock_invalid const &d) = 0;
};
}
//--------------------------------
bcache::validator::ptr superblock_validator();
superblock read_superblock(persistent_data::block_manager::ptr bm,
persistent_data::block_address location = SUPERBLOCK_LOCATION);
void write_superblock(persistent_data::block_manager::ptr bm,
superblock const &sb,
persistent_data::block_address location = SUPERBLOCK_LOCATION);
void check_superblock(superblock const &sb,
persistent_data::block_address nr_metadata_blocks,
superblock_damage::damage_visitor &visitor);
void check_superblock(persistent_data::block_manager::ptr bm,
persistent_data::block_address nr_metadata_blocks,
superblock_damage::damage_visitor &visitor);
}
//----------------------------------------------------------------
#endif