segregate chain and state blockstores.

This paves the way for better object lifetime management.

Concretely, it makes it possible to:
- have different stores backing chain and state data.
- having the same datastore library, but using different parameters.
- attach different caching layers/policies to each class of data, e.g.
  sizing caches differently.
- specifying different retention policies for chain and state data.

This separation is important because:
- access patterns/frequency of chain and state data are different.
- state is derivable from chain, so one could never expunge the chain
  store, and only retain state objects reachable from the last finality
  in the state store.

blockstore/badger/blockstore.go

@@ -110,10 +110,7 @@ func Open(opts Options) (*Blockstore, error) {
 		return nil, fmt.Errorf("failed to open badger blockstore: %w", err)
 	}
 
-	bs := &Blockstore{
+	bs := &Blockstore{DB: db}
-		DB: db,
-	}
-
 	if p := opts.Prefix; p != "" {
 		bs.prefixing = true
 		bs.prefix = []byte(p)

blockstore/badger/blockstore_test_suite.go

@@ -8,18 +8,19 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/filecoin-project/lotus/blockstore"
 	blocks "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
 	u "github.com/ipfs/go-ipfs-util"
 
+	"github.com/filecoin-project/lotus/blockstore"
+
 	"github.com/stretchr/testify/require"
 )
 
 // TODO: move this to go-ipfs-blockstore.
 type Suite struct {
-	NewBlockstore  func(tb testing.TB) (bs blockstore.Blockstore, path string)
+	NewBlockstore  func(tb testing.TB) (bs blockstore.BasicBlockstore, path string)
-	OpenBlockstore func(tb testing.TB, path string) (bs blockstore.Blockstore, err error)
+	OpenBlockstore func(tb testing.TB, path string) (bs blockstore.BasicBlockstore, err error)
 }
 
 func (s *Suite) RunTests(t *testing.T, prefix string) {
@@ -290,7 +291,7 @@ func (s *Suite) TestDelete(t *testing.T) {
 
 }
 
-func insertBlocks(t *testing.T, bs blockstore.Blockstore, count int) []cid.Cid {
+func insertBlocks(t *testing.T, bs blockstore.BasicBlockstore, count int) []cid.Cid {
 	keys := make([]cid.Cid, count)
 	for i := 0; i < count; i++ {
 		block := blocks.NewBlock([]byte(fmt.Sprintf("some data %d", i)))

blockstore/fallback.go

@@ -11,6 +11,19 @@ import (
 	"github.com/ipfs/go-cid"
 )
 
+// UnwrapFallbackStore takes a blockstore, and returns the underlying blockstore
+// if it was a FallbackStore. Otherwise, it just returns the supplied store
+// unmodified.
+func UnwrapFallbackStore(bs Blockstore) (Blockstore, bool) {
+	if fbs, ok := bs.(*FallbackStore); ok {
+		return fbs.Blockstore, true
+	}
+	return bs, false
+}
+
+// FallbackStore is a read-through store that queries another (potentially
+// remote) source if the block is not found locally. If the block is found
+// during the fallback, it stores it in the local store.
 type FallbackStore struct {
 	Blockstore
 
@@ -30,7 +43,7 @@ func (fbs *FallbackStore) SetFallback(missFn func(context.Context, cid.Cid) (blo
 }
 
 func (fbs *FallbackStore) getFallback(c cid.Cid) (blocks.Block, error) {
-	log.Errorw("fallbackstore: Block not found locally, fetching from the network", "cid", c)
+	log.Warnf("fallbackstore: block not found locally, fetching from the network; cid: %s", c)
 	fbs.lk.RLock()
 	defer fbs.lk.RUnlock()
 

blockstore/metrics.go

@@ -0,0 +1,154 @@
+package blockstore
+
+import (
+	"time"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+)
+
+//
+// Currently unused, but kept in repo in case we introduce one of the candidate
+// cache implementations (Freecache, Ristretto), both of which report these
+// metrics.
+//
+
+// CacheMetricsEmitInterval is the interval at which metrics are emitted onto
+// OpenCensus.
+var CacheMetricsEmitInterval = 5 * time.Second
+
+var (
+	CacheName, _ = tag.NewKey("cache_name")
+)
+
+// CacheMeasures groups all metrics emitted by the blockstore caches.
+var CacheMeasures = struct {
+	HitRatio       *stats.Float64Measure
+	Hits           *stats.Int64Measure
+	Misses         *stats.Int64Measure
+	Entries        *stats.Int64Measure
+	QueriesServed  *stats.Int64Measure
+	Adds           *stats.Int64Measure
+	Updates        *stats.Int64Measure
+	Evictions      *stats.Int64Measure
+	CostAdded      *stats.Int64Measure
+	CostEvicted    *stats.Int64Measure
+	SetsDropped    *stats.Int64Measure
+	SetsRejected   *stats.Int64Measure
+	QueriesDropped *stats.Int64Measure
+}{
+	HitRatio:       stats.Float64("blockstore/cache/hit_ratio", "Hit ratio of blockstore cache", stats.UnitDimensionless),
+	Hits:           stats.Int64("blockstore/cache/hits", "Total number of hits at blockstore cache", stats.UnitDimensionless),
+	Misses:         stats.Int64("blockstore/cache/misses", "Total number of misses at blockstore cache", stats.UnitDimensionless),
+	Entries:        stats.Int64("blockstore/cache/entry_count", "Total number of entries currently in the blockstore cache", stats.UnitDimensionless),
+	QueriesServed:  stats.Int64("blockstore/cache/queries_served", "Total number of queries served by the blockstore cache", stats.UnitDimensionless),
+	Adds:           stats.Int64("blockstore/cache/adds", "Total number of adds to blockstore cache", stats.UnitDimensionless),
+	Updates:        stats.Int64("blockstore/cache/updates", "Total number of updates in blockstore cache", stats.UnitDimensionless),
+	Evictions:      stats.Int64("blockstore/cache/evictions", "Total number of evictions from blockstore cache", stats.UnitDimensionless),
+	CostAdded:      stats.Int64("blockstore/cache/cost_added", "Total cost (byte size) of entries added into blockstore cache", stats.UnitBytes),
+	CostEvicted:    stats.Int64("blockstore/cache/cost_evicted", "Total cost (byte size) of entries evicted by blockstore cache", stats.UnitBytes),
+	SetsDropped:    stats.Int64("blockstore/cache/sets_dropped", "Total number of sets dropped by blockstore cache", stats.UnitDimensionless),
+	SetsRejected:   stats.Int64("blockstore/cache/sets_rejected", "Total number of sets rejected by blockstore cache", stats.UnitDimensionless),
+	QueriesDropped: stats.Int64("blockstore/cache/queries_dropped", "Total number of queries dropped by blockstore cache", stats.UnitDimensionless),
+}
+
+// CacheViews groups all cache-related default views.
+var CacheViews = struct {
+	HitRatio       *view.View
+	Hits           *view.View
+	Misses         *view.View
+	Entries        *view.View
+	QueriesServed  *view.View
+	Adds           *view.View
+	Updates        *view.View
+	Evictions      *view.View
+	CostAdded      *view.View
+	CostEvicted    *view.View
+	SetsDropped    *view.View
+	SetsRejected   *view.View
+	QueriesDropped *view.View
+}{
+	HitRatio: &view.View{
+		Measure:     CacheMeasures.HitRatio,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Hits: &view.View{
+		Measure:     CacheMeasures.Hits,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Misses: &view.View{
+		Measure:     CacheMeasures.Misses,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Entries: &view.View{
+		Measure:     CacheMeasures.Entries,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	QueriesServed: &view.View{
+		Measure:     CacheMeasures.QueriesServed,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Adds: &view.View{
+		Measure:     CacheMeasures.Adds,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Updates: &view.View{
+		Measure:     CacheMeasures.Updates,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	Evictions: &view.View{
+		Measure:     CacheMeasures.Evictions,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	CostAdded: &view.View{
+		Measure:     CacheMeasures.CostAdded,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	CostEvicted: &view.View{
+		Measure:     CacheMeasures.CostEvicted,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	SetsDropped: &view.View{
+		Measure:     CacheMeasures.SetsDropped,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	SetsRejected: &view.View{
+		Measure:     CacheMeasures.SetsRejected,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+	QueriesDropped: &view.View{
+		Measure:     CacheMeasures.QueriesDropped,
+		Aggregation: view.LastValue(),
+		TagKeys:     []tag.Key{CacheName},
+	},
+}
+
+// DefaultViews exports all default views for this package.
+var DefaultViews = []*view.View{
+	CacheViews.HitRatio,
+	CacheViews.Hits,
+	CacheViews.Misses,
+	CacheViews.Entries,
+	CacheViews.QueriesServed,
+	CacheViews.Adds,
+	CacheViews.Updates,
+	CacheViews.Evictions,
+	CacheViews.CostAdded,
+	CacheViews.CostEvicted,
+	CacheViews.SetsDropped,
+	CacheViews.SetsRejected,
+	CacheViews.QueriesDropped,
+}

chain/gen/gen.go

@@ -125,7 +125,7 @@ func NewGeneratorWithSectors(numSectors int) (*ChainGen, error) {
 		return nil, xerrors.Errorf("failed to get metadata datastore: %w", err)
 	}
 
-	bs, err := lr.Blockstore(context.TODO(), repo.BlockstoreChain)
+	bs, err := lr.Blockstore(context.TODO(), repo.UniversalBlockstore)
 	if err != nil {
 		return nil, err
 	}

chain/gen/genesis/genesis.go

@@ -406,7 +406,7 @@ func VerifyPreSealedData(ctx context.Context, cs *store.ChainStore, stateroot ci
 		StateBase:      stateroot,
 		Epoch:          0,
 		Rand:           &fakeRand{},
-		Bstore:         cs.Blockstore(),
+		Bstore:         cs.StateBlockstore(),
 		Syscalls:       mkFakedSigSyscalls(cs.VMSys()),
 		CircSupplyCalc: nil,
 		NtwkVersion:    genesisNetworkVersion,

chain/gen/genesis/miners.go

@@ -70,7 +70,7 @@ func SetupStorageMiners(ctx context.Context, cs *store.ChainStore, sroot cid.Cid
 		StateBase:      sroot,
 		Epoch:          0,
 		Rand:           &fakeRand{},
-		Bstore:         cs.Blockstore(),
+		Bstore:         cs.StateBlockstore(),
 		Syscalls:       mkFakedSigSyscalls(cs.VMSys()),
 		CircSupplyCalc: csc,
 		NtwkVersion:    genesisNetworkVersion,

chain/gen/mining.go

@@ -79,7 +79,7 @@ func MinerCreateBlock(ctx context.Context, sm *stmgr.StateManager, w api.WalletA
 		}
 	}
 
-	store := sm.ChainStore().Store(ctx)
+	store := sm.ChainStore().ActorStore(ctx)
 	blsmsgroot, err := toArray(store, blsMsgCids)
 	if err != nil {
 		return nil, xerrors.Errorf("building bls amt: %w", err)

chain/stmgr/call.go

@@ -59,7 +59,7 @@ func (sm *StateManager) Call(ctx context.Context, msg *types.Message, ts *types.
 		StateBase:      bstate,
 		Epoch:          bheight,
 		Rand:           store.NewChainRand(sm.cs, ts.Cids()),
-		Bstore:         sm.cs.Blockstore(),
+		Bstore:         sm.cs.StateBlockstore(),
 		Syscalls:       sm.cs.VMSys(),
 		CircSupplyCalc: sm.GetVMCirculatingSupply,
 		NtwkVersion:    sm.GetNtwkVersion,
@@ -174,7 +174,7 @@ func (sm *StateManager) CallWithGas(ctx context.Context, msg *types.Message, pri
 		StateBase:      state,
 		Epoch:          ts.Height() + 1,
 		Rand:           r,
-		Bstore:         sm.cs.Blockstore(),
+		Bstore:         sm.cs.StateBlockstore(),
 		Syscalls:       sm.cs.VMSys(),
 		CircSupplyCalc: sm.GetVMCirculatingSupply,
 		NtwkVersion:    sm.GetNtwkVersion,

chain/stmgr/forks.go

@@ -504,7 +504,7 @@ func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, _ Migratio
 			}
 		case builtin0.StorageMinerActorCodeID:
 			var st miner0.State
-			if err := sm.ChainStore().Store(ctx).Get(ctx, act.Head, &st); err != nil {
+			if err := sm.ChainStore().ActorStore(ctx).Get(ctx, act.Head, &st); err != nil {
 				return xerrors.Errorf("failed to load miner state: %w", err)
 			}
 
@@ -548,7 +548,7 @@ func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, _ Migratio
 		return cid.Undef, xerrors.Errorf("failed to load power actor: %w", err)
 	}
 
-	cst := cbor.NewCborStore(sm.ChainStore().Blockstore())
+	cst := cbor.NewCborStore(sm.ChainStore().StateBlockstore())
 	if err := cst.Get(ctx, powAct.Head, &ps); err != nil {
 		return cid.Undef, xerrors.Errorf("failed to get power actor state: %w", err)
 	}
@@ -582,7 +582,7 @@ func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, _ Migratio
 			}
 		case builtin0.StorageMinerActorCodeID:
 			var st miner0.State
-			if err := sm.ChainStore().Store(ctx).Get(ctx, act.Head, &st); err != nil {
+			if err := sm.ChainStore().ActorStore(ctx).Get(ctx, act.Head, &st); err != nil {
 				return xerrors.Errorf("failed to load miner state: %w", err)
 			}
 
@@ -591,7 +591,7 @@ func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, _ Migratio
 				return xerrors.Errorf("failed to get miner info: %w", err)
 			}
 
-			sectorsArr, err := adt0.AsArray(sm.ChainStore().Store(ctx), st.Sectors)
+			sectorsArr, err := adt0.AsArray(sm.ChainStore().ActorStore(ctx), st.Sectors)
 			if err != nil {
 				return xerrors.Errorf("failed to load sectors array: %w", err)
 			}
@@ -611,11 +611,11 @@ func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, _ Migratio
 			lbact, err := lbtree.GetActor(addr)
 			if err == nil {
 				var lbst miner0.State
-				if err := sm.ChainStore().Store(ctx).Get(ctx, lbact.Head, &lbst); err != nil {
+				if err := sm.ChainStore().ActorStore(ctx).Get(ctx, lbact.Head, &lbst); err != nil {
 					return xerrors.Errorf("failed to load miner state: %w", err)
 				}
 
-				lbsectors, err := adt0.AsArray(sm.ChainStore().Store(ctx), lbst.Sectors)
+				lbsectors, err := adt0.AsArray(sm.ChainStore().ActorStore(ctx), lbst.Sectors)
 				if err != nil {
 					return xerrors.Errorf("failed to load lb sectors array: %w", err)
 				}
@@ -711,7 +711,7 @@ func UpgradeFaucetBurnRecovery(ctx context.Context, sm *StateManager, _ Migratio
 }
 
 func UpgradeIgnition(ctx context.Context, sm *StateManager, _ MigrationCache, cb ExecCallback, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
-	store := sm.cs.Store(ctx)
+	store := sm.cs.ActorStore(ctx)
 
 	if build.UpgradeLiftoffHeight <= epoch {
 		return cid.Undef, xerrors.Errorf("liftoff height must be beyond ignition height")
@@ -767,7 +767,7 @@ func UpgradeIgnition(ctx context.Context, sm *StateManager, _ MigrationCache, cb
 
 func UpgradeRefuel(ctx context.Context, sm *StateManager, _ MigrationCache, cb ExecCallback, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 
-	store := sm.cs.Store(ctx)
+	store := sm.cs.ActorStore(ctx)
 	tree, err := sm.StateTree(root)
 	if err != nil {
 		return cid.Undef, xerrors.Errorf("getting state tree: %w", err)
@@ -792,7 +792,7 @@ func UpgradeRefuel(ctx context.Context, sm *StateManager, _ MigrationCache, cb E
 }
 
 func UpgradeActorsV2(ctx context.Context, sm *StateManager, _ MigrationCache, cb ExecCallback, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
-	buf := blockstore.NewTieredBstore(sm.cs.Blockstore(), blockstore.NewMemorySync())
+	buf := blockstore.NewTieredBstore(sm.cs.StateBlockstore(), blockstore.NewMemorySync())
 	store := store.ActorStore(ctx, buf)
 
 	info, err := store.Put(ctx, new(types.StateInfo0))
@@ -843,7 +843,7 @@ func UpgradeLiftoff(ctx context.Context, sm *StateManager, _ MigrationCache, cb
 		return cid.Undef, xerrors.Errorf("getting state tree: %w", err)
 	}
 
-	err = setNetworkName(ctx, sm.cs.Store(ctx), tree, "mainnet")
+	err = setNetworkName(ctx, sm.cs.ActorStore(ctx), tree, "mainnet")
 	if err != nil {
 		return cid.Undef, xerrors.Errorf("setting network name: %w", err)
 	}
@@ -852,7 +852,7 @@ func UpgradeLiftoff(ctx context.Context, sm *StateManager, _ MigrationCache, cb
 }
 
 func UpgradeCalico(ctx context.Context, sm *StateManager, _ MigrationCache, cb ExecCallback, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
-	store := sm.cs.Store(ctx)
+	store := sm.cs.ActorStore(ctx)
 	var stateRoot types.StateRoot
 	if err := store.Get(ctx, root, &stateRoot); err != nil {
 		return cid.Undef, xerrors.Errorf("failed to decode state root: %w", err)
@@ -1009,7 +1009,7 @@ func upgradeActorsV3Common(
 	root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet,
 	config nv10.Config,
 ) (cid.Cid, error) {
-	buf := blockstore.NewTieredBstore(sm.cs.Blockstore(), blockstore.NewMemorySync())
+	buf := blockstore.NewTieredBstore(sm.cs.StateBlockstore(), blockstore.NewMemorySync())
 	store := store.ActorStore(ctx, buf)
 
 	// Load the state root.
@@ -1239,7 +1239,7 @@ func resetGenesisMsigs0(ctx context.Context, sm *StateManager, store adt0.Store,
 		return xerrors.Errorf("getting genesis tipset: %w", err)
 	}
 
-	cst := cbor.NewCborStore(sm.cs.Blockstore())
+	cst := cbor.NewCborStore(sm.cs.StateBlockstore())
 	genesisTree, err := state.LoadStateTree(cst, gts.ParentState())
 	if err != nil {
 		return xerrors.Errorf("loading state tree: %w", err)

chain/stmgr/forks_test.go

@@ -125,7 +125,7 @@ func TestForkHeightTriggers(t *testing.T) {
 			Height:  testForkHeight,
 			Migration: func(ctx context.Context, sm *StateManager, cache MigrationCache, cb ExecCallback,
 				root cid.Cid, height abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
-				cst := ipldcbor.NewCborStore(sm.ChainStore().Blockstore())
+				cst := ipldcbor.NewCborStore(sm.ChainStore().StateBlockstore())
 
 				st, err := sm.StateTree(root)
 				if err != nil {

chain/stmgr/read.go

@@ -22,7 +22,7 @@ func (sm *StateManager) ParentStateTsk(tsk types.TipSetKey) (*state.StateTree, e
 }
 
 func (sm *StateManager) ParentState(ts *types.TipSet) (*state.StateTree, error) {
-	cst := cbor.NewCborStore(sm.cs.Blockstore())
+	cst := cbor.NewCborStore(sm.cs.StateBlockstore())
 	state, err := state.LoadStateTree(cst, sm.parentState(ts))
 	if err != nil {
 		return nil, xerrors.Errorf("load state tree: %w", err)
@@ -32,7 +32,7 @@ func (sm *StateManager) ParentState(ts *types.TipSet) (*state.StateTree, error)
 }
 
 func (sm *StateManager) StateTree(st cid.Cid) (*state.StateTree, error) {
-	cst := cbor.NewCborStore(sm.cs.Blockstore())
+	cst := cbor.NewCborStore(sm.cs.StateBlockstore())
 	state, err := state.LoadStateTree(cst, st)
 	if err != nil {
 		return nil, xerrors.Errorf("load state tree: %w", err)

chain/stmgr/stmgr.go

@@ -286,7 +286,7 @@ func (sm *StateManager) ApplyBlocks(ctx context.Context, parentEpoch abi.ChainEp
 			StateBase:      base,
 			Epoch:          epoch,
 			Rand:           r,
-			Bstore:         sm.cs.Blockstore(),
+			Bstore:         sm.cs.StateBlockstore(),
 			Syscalls:       sm.cs.VMSys(),
 			CircSupplyCalc: sm.GetVMCirculatingSupply,
 			NtwkVersion:    sm.GetNtwkVersion,
@@ -430,7 +430,8 @@ func (sm *StateManager) ApplyBlocks(ctx context.Context, parentEpoch abi.ChainEp
 		return cid.Cid{}, cid.Cid{}, err
 	}
 
-	rectarr := blockadt.MakeEmptyArray(sm.cs.Store(ctx))
+	// XXX: Is the height correct? Or should it be epoch-1?
+	rectarr := blockadt.MakeEmptyArray(sm.cs.ActorStore(ctx))
 	for i, receipt := range receipts {
 		if err := rectarr.Set(uint64(i), receipt); err != nil {
 			return cid.Undef, cid.Undef, xerrors.Errorf("failed to build receipts amt: %w", err)
@@ -515,7 +516,7 @@ func (sm *StateManager) ResolveToKeyAddress(ctx context.Context, addr address.Ad
 		ts = sm.cs.GetHeaviestTipSet()
 	}
 
-	cst := cbor.NewCborStore(sm.cs.Blockstore())
+	cst := cbor.NewCborStore(sm.cs.StateBlockstore())
 
 	// First try to resolve the actor in the parent state, so we don't have to compute anything.
 	tree, err := state.LoadStateTree(cst, ts.ParentState())
@@ -556,7 +557,7 @@ func (sm *StateManager) GetBlsPublicKey(ctx context.Context, addr address.Addres
 }
 
 func (sm *StateManager) LookupID(ctx context.Context, addr address.Address, ts *types.TipSet) (address.Address, error) {
-	cst := cbor.NewCborStore(sm.cs.Blockstore())
+	cst := cbor.NewCborStore(sm.cs.StateBlockstore())
 	state, err := state.LoadStateTree(cst, sm.parentState(ts))
 	if err != nil {
 		return address.Undef, xerrors.Errorf("load state tree: %w", err)
@@ -882,7 +883,7 @@ func (sm *StateManager) MarketBalance(ctx context.Context, addr address.Address,
 		return api.MarketBalance{}, err
 	}
 
-	mstate, err := market.Load(sm.cs.Store(ctx), act)
+	mstate, err := market.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return api.MarketBalance{}, err
 	}
@@ -966,7 +967,7 @@ func (sm *StateManager) setupGenesisVestingSchedule(ctx context.Context) error {
 		return xerrors.Errorf("getting genesis tipset state: %w", err)
 	}
 
-	cst := cbor.NewCborStore(sm.cs.Blockstore())
+	cst := cbor.NewCborStore(sm.cs.StateBlockstore())
 	sTree, err := state.LoadStateTree(cst, st)
 	if err != nil {
 		return xerrors.Errorf("loading state tree: %w", err)
@@ -1325,7 +1326,7 @@ func (sm *StateManager) GetCirculatingSupply(ctx context.Context, height abi.Cha
 			unCirc = big.Add(unCirc, actor.Balance)
 
 		case a == market.Address:
-			mst, err := market.Load(sm.cs.Store(ctx), actor)
+			mst, err := market.Load(sm.cs.ActorStore(ctx), actor)
 			if err != nil {
 				return err
 			}
@@ -1342,7 +1343,7 @@ func (sm *StateManager) GetCirculatingSupply(ctx context.Context, height abi.Cha
 			circ = big.Add(circ, actor.Balance)
 
 		case builtin.IsStorageMinerActor(actor.Code):
-			mst, err := miner.Load(sm.cs.Store(ctx), actor)
+			mst, err := miner.Load(sm.cs.ActorStore(ctx), actor)
 			if err != nil {
 				return err
 			}
@@ -1359,7 +1360,7 @@ func (sm *StateManager) GetCirculatingSupply(ctx context.Context, height abi.Cha
 			}
 
 		case builtin.IsMultisigActor(actor.Code):
-			mst, err := multisig.Load(sm.cs.Store(ctx), actor)
+			mst, err := multisig.Load(sm.cs.ActorStore(ctx), actor)
 			if err != nil {
 				return err
 			}
@@ -1413,7 +1414,7 @@ func (sm *StateManager) GetPaychState(ctx context.Context, addr address.Address,
 		return nil, nil, err
 	}
 
-	actState, err := paych.Load(sm.cs.Store(ctx), act)
+	actState, err := paych.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -1431,7 +1432,7 @@ func (sm *StateManager) GetMarketState(ctx context.Context, ts *types.TipSet) (m
 		return nil, err
 	}
 
-	actState, err := market.Load(sm.cs.Store(ctx), act)
+	actState, err := market.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, err
 	}

chain/stmgr/utils.go

@@ -48,7 +48,7 @@ func GetNetworkName(ctx context.Context, sm *StateManager, st cid.Cid) (dtypes.N
 	if err != nil {
 		return "", err
 	}
-	ias, err := init_.Load(sm.cs.Store(ctx), act)
+	ias, err := init_.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return "", err
 	}
@@ -65,7 +65,7 @@ func GetMinerWorkerRaw(ctx context.Context, sm *StateManager, st cid.Cid, maddr
 	if err != nil {
 		return address.Undef, xerrors.Errorf("(get sset) failed to load miner actor: %w", err)
 	}
-	mas, err := miner.Load(sm.cs.Store(ctx), act)
+	mas, err := miner.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return address.Undef, xerrors.Errorf("(get sset) failed to load miner actor state: %w", err)
 	}
@@ -75,7 +75,7 @@ func GetMinerWorkerRaw(ctx context.Context, sm *StateManager, st cid.Cid, maddr
 		return address.Undef, xerrors.Errorf("failed to load actor info: %w", err)
 	}
 
-	return vm.ResolveToKeyAddr(state, sm.cs.Store(ctx), info.Worker)
+	return vm.ResolveToKeyAddr(state, sm.cs.ActorStore(ctx), info.Worker)
 }
 
 func GetPower(ctx context.Context, sm *StateManager, ts *types.TipSet, maddr address.Address) (power.Claim, power.Claim, bool, error) {
@@ -88,7 +88,7 @@ func GetPowerRaw(ctx context.Context, sm *StateManager, st cid.Cid, maddr addres
 		return power.Claim{}, power.Claim{}, false, xerrors.Errorf("(get sset) failed to load power actor state: %w", err)
 	}
 
-	pas, err := power.Load(sm.cs.Store(ctx), act)
+	pas, err := power.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return power.Claim{}, power.Claim{}, false, err
 	}
@@ -123,7 +123,7 @@ func PreCommitInfo(ctx context.Context, sm *StateManager, maddr address.Address,
 		return nil, xerrors.Errorf("(get sset) failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(sm.cs.Store(ctx), act)
+	mas, err := miner.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("(get sset) failed to load miner actor state: %w", err)
 	}
@@ -137,7 +137,7 @@ func MinerSectorInfo(ctx context.Context, sm *StateManager, maddr address.Addres
 		return nil, xerrors.Errorf("(get sset) failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(sm.cs.Store(ctx), act)
+	mas, err := miner.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("(get sset) failed to load miner actor state: %w", err)
 	}
@@ -151,7 +151,7 @@ func GetSectorsForWinningPoSt(ctx context.Context, nv network.Version, pv ffiwra
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(sm.cs.Store(ctx), act)
+	mas, err := miner.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -249,7 +249,7 @@ func GetMinerSlashed(ctx context.Context, sm *StateManager, ts *types.TipSet, ma
 		return false, xerrors.Errorf("failed to load power actor: %w", err)
 	}
 
-	spas, err := power.Load(sm.cs.Store(ctx), act)
+	spas, err := power.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return false, xerrors.Errorf("failed to load power actor state: %w", err)
 	}
@@ -272,7 +272,7 @@ func GetStorageDeal(ctx context.Context, sm *StateManager, dealID abi.DealID, ts
 		return nil, xerrors.Errorf("failed to load market actor: %w", err)
 	}
 
-	state, err := market.Load(sm.cs.Store(ctx), act)
+	state, err := market.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load market actor state: %w", err)
 	}
@@ -320,7 +320,7 @@ func ListMinerActors(ctx context.Context, sm *StateManager, ts *types.TipSet) ([
 		return nil, xerrors.Errorf("failed to load power actor: %w", err)
 	}
 
-	powState, err := power.Load(sm.cs.Store(ctx), act)
+	powState, err := power.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load power actor state: %w", err)
 	}
@@ -353,7 +353,7 @@ func ComputeState(ctx context.Context, sm *StateManager, height abi.ChainEpoch,
 		StateBase:      base,
 		Epoch:          height,
 		Rand:           r,
-		Bstore:         sm.cs.Blockstore(),
+		Bstore:         sm.cs.StateBlockstore(),
 		Syscalls:       sm.cs.VMSys(),
 		CircSupplyCalc: sm.GetVMCirculatingSupply,
 		NtwkVersion:    sm.GetNtwkVersion,
@@ -474,7 +474,7 @@ func MinerGetBaseInfo(ctx context.Context, sm *StateManager, bcs beacon.Schedule
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(sm.cs.Store(ctx), act)
+	mas, err := miner.Load(sm.cs.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -623,7 +623,7 @@ func minerHasMinPower(ctx context.Context, sm *StateManager, addr address.Addres
 		return false, xerrors.Errorf("loading power actor state: %w", err)
 	}
 
-	ps, err := power.Load(sm.cs.Store(ctx), pact)
+	ps, err := power.Load(sm.cs.ActorStore(ctx), pact)
 	if err != nil {
 		return false, err
 	}
@@ -654,7 +654,7 @@ func MinerEligibleToMine(ctx context.Context, sm *StateManager, addr address.Add
 		return false, xerrors.Errorf("loading power actor state: %w", err)
 	}
 
-	pstate, err := power.Load(sm.cs.Store(ctx), pact)
+	pstate, err := power.Load(sm.cs.ActorStore(ctx), pact)
 	if err != nil {
 		return false, err
 	}
@@ -664,7 +664,7 @@ func MinerEligibleToMine(ctx context.Context, sm *StateManager, addr address.Add
 		return false, xerrors.Errorf("loading miner actor state: %w", err)
 	}
 
-	mstate, err := miner.Load(sm.cs.Store(ctx), mact)
+	mstate, err := miner.Load(sm.cs.ActorStore(ctx), mact)
 	if err != nil {
 		return false, err
 	}
@@ -696,7 +696,7 @@ func MinerEligibleToMine(ctx context.Context, sm *StateManager, addr address.Add
 }
 
 func CheckTotalFIL(ctx context.Context, sm *StateManager, ts *types.TipSet) (abi.TokenAmount, error) {
-	str, err := state.LoadStateTree(sm.ChainStore().Store(ctx), ts.ParentState())
+	str, err := state.LoadStateTree(sm.ChainStore().ActorStore(ctx), ts.ParentState())
 	if err != nil {
 		return abi.TokenAmount{}, err
 	}

chain/store/store.go

@@ -107,11 +107,11 @@ type HeadChangeEvt struct {
 //   1. a tipset cache
 //   2. a block => messages references cache.
 type ChainStore struct {
-	bs      bstore.Blockstore
+	chainBlockstore bstore.Blockstore
-	localbs bstore.Blockstore
+	stateBlockstore bstore.Blockstore
-	ds      dstore.Batching
+	metadataDs      dstore.Batching
 
-	localviewer bstore.Viewer
+	chainLocalBlockstore bstore.Blockstore
 
 	heaviestLk sync.Mutex
 	heaviest   *types.TipSet
@@ -139,30 +139,30 @@ type ChainStore struct {
 	wg       sync.WaitGroup
 }
 
-// localbs is guaranteed to fail Get* if requested block isn't stored locally
+// chainLocalBlockstore is guaranteed to fail Get* if requested block isn't stored locally
-func NewChainStore(bs bstore.Blockstore, localbs bstore.Blockstore, ds dstore.Batching, vmcalls vm.SyscallBuilder, j journal.Journal) *ChainStore {
+func NewChainStore(chainBs bstore.Blockstore, stateBs bstore.Blockstore, ds dstore.Batching, vmcalls vm.SyscallBuilder, j journal.Journal) *ChainStore {
-	mmCache, _ := lru.NewARC(DefaultMsgMetaCacheSize)
+	c, _ := lru.NewARC(DefaultMsgMetaCacheSize)
-	tsCache, _ := lru.NewARC(DefaultTipSetCacheSize)
+	tsc, _ := lru.NewARC(DefaultTipSetCacheSize)
 	if j == nil {
 		j = journal.NilJournal()
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())
+	// unwraps the fallback store in case one is configured.
+	// some methods _need_ to operate on a local blockstore only.
+	localbs, _ := bstore.UnwrapFallbackStore(chainBs)
 	cs := &ChainStore{
-		bs:       bs,
+		chainBlockstore:      chainBs,
-		localbs:  localbs,
+		stateBlockstore:      stateBs,
-		ds:       ds,
+		chainLocalBlockstore: localbs,
-		bestTips: pubsub.New(64),
+		metadataDs:           ds,
-		tipsets:  make(map[abi.ChainEpoch][]cid.Cid),
+		bestTips:             pubsub.New(64),
-		mmCache:  mmCache,
+		tipsets:              make(map[abi.ChainEpoch][]cid.Cid),
-		tsCache:  tsCache,
+		mmCache:              c,
-		vmcalls:  vmcalls,
+		tsCache:              tsc,
-		cancelFn: cancel,
+		vmcalls:              vmcalls,
-		journal:  j,
+		cancelFn:             cancel,
-	}
+		journal:              j,
-
-	if v, ok := localbs.(bstore.Viewer); ok {
-		cs.localviewer = v
 	}
 
 	cs.evtTypes = [1]journal.EventType{
@@ -216,7 +216,7 @@ func (cs *ChainStore) Close() error {
 }
 
 func (cs *ChainStore) Load() error {
-	head, err := cs.ds.Get(chainHeadKey)
+	head, err := cs.metadataDs.Get(chainHeadKey)
 	if err == dstore.ErrNotFound {
 		log.Warn("no previous chain state found")
 		return nil
@@ -246,7 +246,7 @@ func (cs *ChainStore) writeHead(ts *types.TipSet) error {
 		return xerrors.Errorf("failed to marshal tipset: %w", err)
 	}
 
-	if err := cs.ds.Put(chainHeadKey, data); err != nil {
+	if err := cs.metadataDs.Put(chainHeadKey, data); err != nil {
 		return xerrors.Errorf("failed to write chain head to datastore: %w", err)
 	}
 
@@ -306,13 +306,13 @@ func (cs *ChainStore) SubscribeHeadChanges(f ReorgNotifee) {
 func (cs *ChainStore) IsBlockValidated(ctx context.Context, blkid cid.Cid) (bool, error) {
 	key := blockValidationCacheKeyPrefix.Instance(blkid.String())
 
-	return cs.ds.Has(key)
+	return cs.metadataDs.Has(key)
 }
 
 func (cs *ChainStore) MarkBlockAsValidated(ctx context.Context, blkid cid.Cid) error {
 	key := blockValidationCacheKeyPrefix.Instance(blkid.String())
 
-	if err := cs.ds.Put(key, []byte{0}); err != nil {
+	if err := cs.metadataDs.Put(key, []byte{0}); err != nil {
 		return xerrors.Errorf("cache block validation: %w", err)
 	}
 
@@ -322,7 +322,7 @@ func (cs *ChainStore) MarkBlockAsValidated(ctx context.Context, blkid cid.Cid) e
 func (cs *ChainStore) UnmarkBlockAsValidated(ctx context.Context, blkid cid.Cid) error {
 	key := blockValidationCacheKeyPrefix.Instance(blkid.String())
 
-	if err := cs.ds.Delete(key); err != nil {
+	if err := cs.metadataDs.Delete(key); err != nil {
 		return xerrors.Errorf("removing from valid block cache: %w", err)
 	}
 
@@ -339,7 +339,7 @@ func (cs *ChainStore) SetGenesis(b *types.BlockHeader) error {
 		return err
 	}
 
-	return cs.ds.Put(dstore.NewKey("0"), b.Cid().Bytes())
+	return cs.metadataDs.Put(dstore.NewKey("0"), b.Cid().Bytes())
 }
 
 func (cs *ChainStore) PutTipSet(ctx context.Context, ts *types.TipSet) error {
@@ -594,7 +594,7 @@ func (cs *ChainStore) takeHeaviestTipSet(ctx context.Context, ts *types.TipSet)
 // FlushValidationCache removes all results of block validation from the
 // chain metadata store. Usually the first step after a new chain import.
 func (cs *ChainStore) FlushValidationCache() error {
-	return FlushValidationCache(cs.ds)
+	return FlushValidationCache(cs.metadataDs)
 }
 
 func FlushValidationCache(ds datastore.Batching) error {
@@ -653,7 +653,7 @@ func (cs *ChainStore) SetHead(ts *types.TipSet) error {
 // Contains returns whether our BlockStore has all blocks in the supplied TipSet.
 func (cs *ChainStore) Contains(ts *types.TipSet) (bool, error) {
 	for _, c := range ts.Cids() {
-		has, err := cs.bs.Has(c)
+		has, err := cs.chainBlockstore.Has(c)
 		if err != nil {
 			return false, err
 		}
@@ -668,16 +668,8 @@ func (cs *ChainStore) Contains(ts *types.TipSet) (bool, error) {
 // GetBlock fetches a BlockHeader with the supplied CID. It returns
 // blockstore.ErrNotFound if the block was not found in the BlockStore.
 func (cs *ChainStore) GetBlock(c cid.Cid) (*types.BlockHeader, error) {
-	if cs.localviewer == nil {
-		sb, err := cs.localbs.Get(c)
-		if err != nil {
-			return nil, err
-		}
-		return types.DecodeBlock(sb.RawData())
-	}
-
 	var blk *types.BlockHeader
-	err := cs.localviewer.View(c, func(b []byte) (err error) {
+	err := cs.chainLocalBlockstore.View(c, func(b []byte) (err error) {
 		blk, err = types.DecodeBlock(b)
 		return err
 	})
@@ -851,7 +843,7 @@ func (cs *ChainStore) PersistBlockHeaders(b ...*types.BlockHeader) error {
 			end = len(b)
 		}
 
-		err = multierr.Append(err, cs.bs.PutMany(sbs[start:end]))
+		err = multierr.Append(err, cs.chainLocalBlockstore.PutMany(sbs[start:end]))
 	}
 
 	return err
@@ -875,7 +867,7 @@ func PutMessage(bs bstore.Blockstore, m storable) (cid.Cid, error) {
 }
 
 func (cs *ChainStore) PutMessage(m storable) (cid.Cid, error) {
-	return PutMessage(cs.bs, m)
+	return PutMessage(cs.chainBlockstore, m)
 }
 
 func (cs *ChainStore) expandTipset(b *types.BlockHeader) (*types.TipSet, error) {
@@ -936,7 +928,7 @@ func (cs *ChainStore) AddBlock(ctx context.Context, b *types.BlockHeader) error
 }
 
 func (cs *ChainStore) GetGenesis() (*types.BlockHeader, error) {
-	data, err := cs.ds.Get(dstore.NewKey("0"))
+	data, err := cs.metadataDs.Get(dstore.NewKey("0"))
 	if err != nil {
 		return nil, err
 	}
@@ -962,17 +954,8 @@ func (cs *ChainStore) GetCMessage(c cid.Cid) (types.ChainMsg, error) {
 }
 
 func (cs *ChainStore) GetMessage(c cid.Cid) (*types.Message, error) {
-	if cs.localviewer == nil {
-		sb, err := cs.localbs.Get(c)
-		if err != nil {
-			log.Errorf("get message get failed: %s: %s", c, err)
-			return nil, err
-		}
-		return types.DecodeMessage(sb.RawData())
-	}
-
 	var msg *types.Message
-	err := cs.localviewer.View(c, func(b []byte) (err error) {
+	err := cs.chainLocalBlockstore.View(c, func(b []byte) (err error) {
 		msg, err = types.DecodeMessage(b)
 		return err
 	})
@@ -980,17 +963,8 @@ func (cs *ChainStore) GetMessage(c cid.Cid) (*types.Message, error) {
 }
 
 func (cs *ChainStore) GetSignedMessage(c cid.Cid) (*types.SignedMessage, error) {
-	if cs.localviewer == nil {
-		sb, err := cs.localbs.Get(c)
-		if err != nil {
-			log.Errorf("get message get failed: %s: %s", c, err)
-			return nil, err
-		}
-		return types.DecodeSignedMessage(sb.RawData())
-	}
-
 	var msg *types.SignedMessage
-	err := cs.localviewer.View(c, func(b []byte) (err error) {
+	err := cs.chainLocalBlockstore.View(c, func(b []byte) (err error) {
 		msg, err = types.DecodeSignedMessage(b)
 		return err
 	})
@@ -1000,7 +974,7 @@ func (cs *ChainStore) GetSignedMessage(c cid.Cid) (*types.SignedMessage, error)
 func (cs *ChainStore) readAMTCids(root cid.Cid) ([]cid.Cid, error) {
 	ctx := context.TODO()
 	// block headers use adt0, for now.
-	a, err := blockadt.AsArray(cs.Store(ctx), root)
+	a, err := blockadt.AsArray(cs.ActorStore(ctx), root)
 	if err != nil {
 		return nil, xerrors.Errorf("amt load: %w", err)
 	}
@@ -1124,7 +1098,7 @@ func (cs *ChainStore) ReadMsgMetaCids(mmc cid.Cid) ([]cid.Cid, []cid.Cid, error)
 		return mmcids.bls, mmcids.secpk, nil
 	}
 
-	cst := cbor.NewCborStore(cs.localbs)
+	cst := cbor.NewCborStore(cs.chainLocalBlockstore)
 	var msgmeta types.MsgMeta
 	if err := cst.Get(context.TODO(), mmc, &msgmeta); err != nil {
 		return nil, nil, xerrors.Errorf("failed to load msgmeta (%s): %w", mmc, err)
@@ -1194,7 +1168,7 @@ func (cs *ChainStore) MessagesForBlock(b *types.BlockHeader) ([]*types.Message,
 func (cs *ChainStore) GetParentReceipt(b *types.BlockHeader, i int) (*types.MessageReceipt, error) {
 	ctx := context.TODO()
 	// block headers use adt0, for now.
-	a, err := blockadt.AsArray(cs.Store(ctx), b.ParentMessageReceipts)
+	a, err := blockadt.AsArray(cs.ActorStore(ctx), b.ParentMessageReceipts)
 	if err != nil {
 		return nil, xerrors.Errorf("amt load: %w", err)
 	}
@@ -1237,16 +1211,26 @@ func (cs *ChainStore) LoadSignedMessagesFromCids(cids []cid.Cid) ([]*types.Signe
 	return msgs, nil
 }
 
-func (cs *ChainStore) Blockstore() bstore.Blockstore {
+// ChainBlockstore returns the chain blockstore. Currently the chain and state
-	return cs.bs
+// // stores are both backed by the same physical store, albeit with different
+// // caching policies, but in the future they will segregate.
+func (cs *ChainStore) ChainBlockstore() bstore.Blockstore {
+	return cs.chainBlockstore
+}
+
+// StateBlockstore returns the state blockstore. Currently the chain and state
+// stores are both backed by the same physical store, albeit with different
+// caching policies, but in the future they will segregate.
+func (cs *ChainStore) StateBlockstore() bstore.Blockstore {
+	return cs.stateBlockstore
 }
 
 func ActorStore(ctx context.Context, bs bstore.Blockstore) adt.Store {
 	return adt.WrapStore(ctx, cbor.NewCborStore(bs))
 }
 
-func (cs *ChainStore) Store(ctx context.Context) adt.Store {
+func (cs *ChainStore) ActorStore(ctx context.Context) adt.Store {
-	return ActorStore(ctx, cs.bs)
+	return ActorStore(ctx, cs.stateBlockstore)
 }
 
 func (cs *ChainStore) VMSys() vm.SyscallBuilder {
@@ -1444,8 +1428,8 @@ func (cs *ChainStore) Export(ctx context.Context, ts *types.TipSet, inclRecentRo
 		return xerrors.Errorf("failed to write car header: %s", err)
 	}
 
-	return cs.WalkSnapshot(ctx, ts, inclRecentRoots, skipOldMsgs, func(c cid.Cid) error {
+	return cs.WalkSnapshot(ctx, ts, inclRecentRoots, skipOldMsgs, true, func(c cid.Cid) error {
-		blk, err := cs.bs.Get(c)
+		blk, err := cs.chainBlockstore.Get(c)
 		if err != nil {
 			return xerrors.Errorf("writing object to car, bs.Get: %w", err)
 		}
@@ -1458,7 +1442,7 @@ func (cs *ChainStore) Export(ctx context.Context, ts *types.TipSet, inclRecentRo
 	})
 }
 
-func (cs *ChainStore) WalkSnapshot(ctx context.Context, ts *types.TipSet, inclRecentRoots abi.ChainEpoch, skipOldMsgs bool, cb func(cid.Cid) error) error {
+func (cs *ChainStore) WalkSnapshot(ctx context.Context, ts *types.TipSet, inclRecentRoots abi.ChainEpoch, skipOldMsgs, skipMsgReceipts bool, cb func(cid.Cid) error) error {
 	if ts == nil {
 		ts = cs.GetHeaviestTipSet()
 	}
@@ -1478,7 +1462,7 @@ func (cs *ChainStore) WalkSnapshot(ctx context.Context, ts *types.TipSet, inclRe
 			return err
 		}
 
-		data, err := cs.bs.Get(blk)
+		data, err := cs.chainBlockstore.Get(blk)
 		if err != nil {
 			return xerrors.Errorf("getting block: %w", err)
 		}
@@ -1498,7 +1482,7 @@ func (cs *ChainStore) WalkSnapshot(ctx context.Context, ts *types.TipSet, inclRe
 		var cids []cid.Cid
 		if !skipOldMsgs || b.Height > ts.Height()-inclRecentRoots {
 			if walked.Visit(b.Messages) {
-				mcids, err := recurseLinks(cs.bs, walked, b.Messages, []cid.Cid{b.Messages})
+				mcids, err := recurseLinks(cs.chainBlockstore, walked, b.Messages, []cid.Cid{b.Messages})
 				if err != nil {
 					return xerrors.Errorf("recursing messages failed: %w", err)
 				}
@@ -1519,13 +1503,17 @@ func (cs *ChainStore) WalkSnapshot(ctx context.Context, ts *types.TipSet, inclRe
 
 		if b.Height == 0 || b.Height > ts.Height()-inclRecentRoots {
 			if walked.Visit(b.ParentStateRoot) {
-				cids, err := recurseLinks(cs.bs, walked, b.ParentStateRoot, []cid.Cid{b.ParentStateRoot})
+				cids, err := recurseLinks(cs.chainBlockstore, walked, b.ParentStateRoot, []cid.Cid{b.ParentStateRoot})
 				if err != nil {
 					return xerrors.Errorf("recursing genesis state failed: %w", err)
 				}
 
 				out = append(out, cids...)
 			}
+
+			if !skipMsgReceipts && walked.Visit(b.ParentMessageReceipts) {
+				out = append(out, b.ParentMessageReceipts)
+			}
 		}
 
 		for _, c := range out {
@@ -1561,7 +1549,7 @@ func (cs *ChainStore) WalkSnapshot(ctx context.Context, ts *types.TipSet, inclRe
 }
 
 func (cs *ChainStore) Import(r io.Reader) (*types.TipSet, error) {
-	header, err := car.LoadCar(cs.Blockstore(), r)
+	header, err := car.LoadCar(cs.StateBlockstore(), r)
 	if err != nil {
 		return nil, xerrors.Errorf("loadcar failed: %w", err)
 	}

chain/store/store_test.go

@@ -52,7 +52,7 @@ func BenchmarkGetRandomness(b *testing.B) {
 		b.Fatal(err)
 	}
 
-	bs, err := lr.Blockstore(context.TODO(), repo.BlockstoreChain)
+	bs, err := lr.Blockstore(context.TODO(), repo.UniversalBlockstore)
 	if err != nil {
 		b.Fatal(err)
 	}

chain/store/weight.go

@@ -28,7 +28,7 @@ func (cs *ChainStore) Weight(ctx context.Context, ts *types.TipSet) (types.BigIn
 
 	tpow := big2.Zero()
 	{
-		cst := cbor.NewCborStore(cs.Blockstore())
+		cst := cbor.NewCborStore(cs.StateBlockstore())
 		state, err := state.LoadStateTree(cst, ts.ParentState())
 		if err != nil {
 			return types.NewInt(0), xerrors.Errorf("load state tree: %w", err)
@@ -39,7 +39,7 @@ func (cs *ChainStore) Weight(ctx context.Context, ts *types.TipSet) (types.BigIn
 			return types.NewInt(0), xerrors.Errorf("get power actor: %w", err)
 		}
 
-		powState, err := power.Load(cs.Store(ctx), act)
+		powState, err := power.Load(cs.ActorStore(ctx), act)
 		if err != nil {
 			return types.NewInt(0), xerrors.Errorf("failed to load power actor state: %w", err)
 		}

chain/sync.go

@@ -354,7 +354,7 @@ func (syncer *Syncer) ValidateMsgMeta(fblk *types.FullBlock) error {
 	}
 
 	// Finally, flush.
-	return vm.Copy(context.TODO(), blockstore, syncer.store.Blockstore(), smroot)
+	return vm.Copy(context.TODO(), blockstore, syncer.store.ChainBlockstore(), smroot)
 }
 
 func (syncer *Syncer) LocalPeer() peer.ID {
@@ -640,7 +640,7 @@ func (syncer *Syncer) minerIsValid(ctx context.Context, maddr address.Address, b
 		return xerrors.Errorf("failed to load power actor: %w", err)
 	}
 
-	powState, err := power.Load(syncer.store.Store(ctx), act)
+	powState, err := power.Load(syncer.store.ActorStore(ctx), act)
 	if err != nil {
 		return xerrors.Errorf("failed to load power actor state: %w", err)
 	}
@@ -1055,7 +1055,7 @@ func (syncer *Syncer) checkBlockMessages(ctx context.Context, b *types.FullBlock
 		return err
 	}
 
-	st, err := state.LoadStateTree(syncer.store.Store(ctx), stateroot)
+	st, err := state.LoadStateTree(syncer.store.ActorStore(ctx), stateroot)
 	if err != nil {
 		return xerrors.Errorf("failed to load base state tree: %w", err)
 	}
@@ -1172,7 +1172,7 @@ func (syncer *Syncer) checkBlockMessages(ctx context.Context, b *types.FullBlock
 	}
 
 	// Finally, flush.
-	return vm.Copy(ctx, tmpbs, syncer.store.Blockstore(), mrcid)
+	return vm.Copy(ctx, tmpbs, syncer.store.ChainBlockstore(), mrcid)
 }
 
 func (syncer *Syncer) verifyBlsAggregate(ctx context.Context, sig *crypto.Signature, msgs []cid.Cid, pubks [][]byte) error {
@@ -1574,7 +1574,7 @@ func (syncer *Syncer) iterFullTipsets(ctx context.Context, headers []*types.TipS
 				return err
 			}
 
-			if err := copyBlockstore(ctx, bs, syncer.store.Blockstore()); err != nil {
+			if err := copyBlockstore(ctx, bs, syncer.store.ChainBlockstore()); err != nil {
 				return xerrors.Errorf("message processing failed: %w", err)
 			}
 		}

cmd/lotus-bench/import.go

@@ -20,7 +20,6 @@ import (
 	"github.com/cockroachdb/pebble"
 	"github.com/cockroachdb/pebble/bloom"
 	"github.com/ipfs/go-cid"
-	metricsi "github.com/ipfs/go-metrics-interface"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 
@@ -204,7 +203,7 @@ var importBenchCmd = &cli.Command{
 		case cctx.Bool("use-native-badger"):
 			log.Info("using native badger")
 			var opts badgerbs.Options
-			if opts, err = repo.BadgerBlockstoreOptions(repo.BlockstoreChain, tdir, false); err != nil {
+			if opts, err = repo.BadgerBlockstoreOptions(repo.UniversalBlockstore, tdir, false); err != nil {
 				return err
 			}
 			opts.SyncWrites = false
@@ -236,14 +235,6 @@ var importBenchCmd = &cli.Command{
 			defer c.Close() //nolint:errcheck
 		}
 
-		ctx := metricsi.CtxScope(context.Background(), "lotus")
-		cacheOpts := blockstore.DefaultCacheOpts()
-		cacheOpts.HasBloomFilterSize = 0
-		bs, err = blockstore.CachedBlockstore(ctx, bs, cacheOpts)
-		if err != nil {
-			return err
-		}
-
 		var verifier ffiwrapper.Verifier = ffiwrapper.ProofVerifier
 		if cctx.IsSet("syscall-cache") {
 			scds, err := badger.NewDatastore(cctx.String("syscall-cache"), &badger.DefaultOptions)
@@ -267,6 +258,15 @@ var importBenchCmd = &cli.Command{
 
 		stm := stmgr.NewStateManager(cs)
 
+		var carFile *os.File
+		// open the CAR file if one is provided.
+		if path := cctx.String("car"); path != "" {
+			var err error
+			if carFile, err = os.Open(path); err != nil {
+				return xerrors.Errorf("failed to open provided CAR file: %w", err)
+			}
+		}
+
 		startTime := time.Now()
 
 		// register a gauge that reports how long since the measurable
@@ -308,18 +308,7 @@ var importBenchCmd = &cli.Command{
 			writeProfile("allocs")
 		}()
 
-		var carFile *os.File
-
-		// open the CAR file if one is provided.
-		if path := cctx.String("car"); path != "" {
-			var err error
-			if carFile, err = os.Open(path); err != nil {
-				return xerrors.Errorf("failed to open provided CAR file: %w", err)
-			}
-		}
-
 		var head *types.TipSet
-
 		// --- IMPORT ---
 		if !cctx.Bool("no-import") {
 			if cctx.Bool("global-profile") {

cmd/lotus-shed/balances.go

@@ -175,7 +175,7 @@ var chainBalanceStateCmd = &cli.Command{
 
 		defer lkrepo.Close() //nolint:errcheck
 
-		bs, err := lkrepo.Blockstore(ctx, repo.BlockstoreChain)
+		bs, err := lkrepo.Blockstore(ctx, repo.UniversalBlockstore)
 		if err != nil {
 			return fmt.Errorf("failed to open blockstore: %w", err)
 		}
@@ -396,7 +396,7 @@ var chainPledgeCmd = &cli.Command{
 
 		defer lkrepo.Close() //nolint:errcheck
 
-		bs, err := lkrepo.Blockstore(ctx, repo.BlockstoreChain)
+		bs, err := lkrepo.Blockstore(ctx, repo.UniversalBlockstore)
 		if err != nil {
 			return xerrors.Errorf("failed to open blockstore: %w", err)
 		}

cmd/lotus-shed/datastore.go

@@ -319,7 +319,7 @@ var datastoreRewriteCmd = &cli.Command{
 		)
 
 		// open the destination (to) store.
-		opts, err := repo.BadgerBlockstoreOptions(repo.BlockstoreChain, toPath, false)
+		opts, err := repo.BadgerBlockstoreOptions(repo.UniversalBlockstore, toPath, false)
 		if err != nil {
 			return xerrors.Errorf("failed to get badger options: %w", err)
 		}
@@ -329,7 +329,7 @@ var datastoreRewriteCmd = &cli.Command{
 		}
 
 		// open the source (from) store.
-		opts, err = repo.BadgerBlockstoreOptions(repo.BlockstoreChain, fromPath, true)
+		opts, err = repo.BadgerBlockstoreOptions(repo.UniversalBlockstore, fromPath, true)
 		if err != nil {
 			return xerrors.Errorf("failed to get badger options: %w", err)
 		}

cmd/lotus-shed/export.go

@@ -72,7 +72,7 @@ var exportChainCmd = &cli.Command{
 
 		defer fi.Close() //nolint:errcheck
 
-		bs, err := lr.Blockstore(ctx, repo.BlockstoreChain)
+		bs, err := lr.Blockstore(ctx, repo.UniversalBlockstore)
 		if err != nil {
 			return fmt.Errorf("failed to open blockstore: %w", err)
 		}

cmd/lotus-shed/import-car.go

@@ -47,7 +47,7 @@ var importCarCmd = &cli.Command{
 			return xerrors.Errorf("opening the car file: %w", err)
 		}
 
-		bs, err := lr.Blockstore(ctx, repo.BlockstoreChain)
+		bs, err := lr.Blockstore(ctx, repo.UniversalBlockstore)
 		if err != nil {
 			return err
 		}
@@ -118,7 +118,7 @@ var importObjectCmd = &cli.Command{
 		}
 		defer lr.Close() //nolint:errcheck
 
-		bs, err := lr.Blockstore(ctx, repo.BlockstoreChain)
+		bs, err := lr.Blockstore(ctx, repo.UniversalBlockstore)
 		if err != nil {
 			return fmt.Errorf("failed to open blockstore: %w", err)
 		}

cmd/lotus-shed/pruning.go

@@ -131,7 +131,7 @@ var stateTreePruneCmd = &cli.Command{
 
 		defer lkrepo.Close() //nolint:errcheck
 
-		bs, err := lkrepo.Blockstore(ctx, repo.BlockstoreChain)
+		bs, err := lkrepo.Blockstore(ctx, repo.UniversalBlockstore)
 		if err != nil {
 			return fmt.Errorf("failed to open blockstore: %w", err)
 		}
@@ -191,7 +191,7 @@ var stateTreePruneCmd = &cli.Command{
 
 		rrLb := abi.ChainEpoch(cctx.Int64("keep-from-lookback"))
 
-		if err := cs.WalkSnapshot(ctx, ts, rrLb, true, func(c cid.Cid) error {
+		if err := cs.WalkSnapshot(ctx, ts, rrLb, true, true, func(c cid.Cid) error {
 			if goodSet.Len()%20 == 0 {
 				fmt.Printf("\renumerating keep set: %d             ", goodSet.Len())
 			}

cmd/lotus/daemon.go

@@ -432,7 +432,7 @@ func ImportChain(ctx context.Context, r repo.Repo, fname string, snapshot bool)
 	}
 	defer lr.Close() //nolint:errcheck
 
-	bs, err := lr.Blockstore(ctx, repo.BlockstoreChain)
+	bs, err := lr.Blockstore(ctx, repo.UniversalBlockstore)
 	if err != nil {
 		return xerrors.Errorf("failed to open blockstore: %w", err)
 	}

documentation/en/architecture/architecture.md

@@ -311,7 +311,7 @@ FIXME: Maybe mention the `Batching` interface as the developer will stumble upon
 
 FIXME: IPFS blocks vs Filecoin blocks ideally happens before this / here
 
-The [`Blockstore` interface](`github.com/filecoin-project/lotus/lib/blockstore.go`) structures the key-value pair
+The [`Blockstore` interface](`github.com/filecoin-project/lotus/blockstore/blockstore.go`) structures the key-value pair
 into the CID format for the key and the [`Block` interface](`github.com/ipfs/go-block-format/blocks.go`) for the value.
 The `Block` value is just a raw string of bytes addressed by its hash, which is included in the CID key.
 

go.mod

@@ -143,7 +143,7 @@ require (
 	go.uber.org/zap v1.16.0
 	golang.org/x/net v0.0.0-20201021035429-f5854403a974
 	golang.org/x/sync v0.0.0-20201207232520-09787c993a3a
-	golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f
+	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68
 	golang.org/x/time v0.0.0-20191024005414-555d28b269f0
 	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1
 	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect

go.sum

@@ -1754,8 +1754,9 @@ golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200602225109-6fdc65e7d980/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200812155832-6a926be9bd1d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200926100807-9d91bd62050c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f h1:+Nyd8tzPX9R7BWHguqsrbFdRx3WQ/1ib8I44HXV5yTA=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

metrics/metrics.go

@@ -9,10 +9,12 @@ import (
 	"go.opencensus.io/tag"
 
 	rpcmetrics "github.com/filecoin-project/go-jsonrpc/metrics"
+
+	"github.com/filecoin-project/lotus/blockstore"
 )
 
 // Distribution
-var defaultMillisecondsDistribution = view.Distribution(0.01, 0.05, 0.1, 0.3, 0.6, 0.8, 1, 2, 3, 4, 5, 6, 8, 10, 13, 16, 20, 25, 30, 40, 50, 65, 80, 100, 130, 160, 200, 250, 300, 400, 500, 650, 800, 1000, 2000, 5000, 10000, 20000, 50000, 100000)
+var defaultMillisecondsDistribution = view.Distribution(0.01, 0.05, 0.1, 0.3, 0.6, 0.8, 1, 2, 3, 4, 5, 6, 8, 10, 13, 16, 20, 25, 30, 40, 50, 65, 80, 100, 130, 160, 200, 250, 300, 400, 500, 650, 800, 1000, 2000, 3000, 4000, 5000, 7500, 10000, 20000, 50000, 100000)
 
 // Global Tags
 var (
@@ -179,33 +181,37 @@ var (
 )
 
 // DefaultViews is an array of OpenCensus views for metric gathering purposes
-var DefaultViews = append([]*view.View{
+var DefaultViews = func() []*view.View {
-	InfoView,
+	views := []*view.View{
-	ChainNodeHeightView,
+		InfoView,
-	ChainNodeHeightExpectedView,
+		ChainNodeHeightView,
-	ChainNodeWorkerHeightView,
+		ChainNodeHeightExpectedView,
-	BlockReceivedView,
+		ChainNodeWorkerHeightView,
-	BlockValidationFailureView,
+		BlockReceivedView,
-	BlockValidationSuccessView,
+		BlockValidationFailureView,
-	BlockValidationDurationView,
+		BlockValidationSuccessView,
-	BlockDelayView,
+		BlockValidationDurationView,
-	MessagePublishedView,
+		BlockDelayView,
-	MessageReceivedView,
+		MessagePublishedView,
-	MessageValidationFailureView,
+		MessageReceivedView,
-	MessageValidationSuccessView,
+		MessageValidationFailureView,
-	PeerCountView,
+		MessageValidationSuccessView,
-	PubsubPublishMessageView,
+		PeerCountView,
-	PubsubDeliverMessageView,
+		PubsubPublishMessageView,
-	PubsubRejectMessageView,
+		PubsubDeliverMessageView,
-	PubsubDuplicateMessageView,
+		PubsubRejectMessageView,
-	PubsubRecvRPCView,
+		PubsubDuplicateMessageView,
-	PubsubSendRPCView,
+		PubsubRecvRPCView,
-	PubsubDropRPCView,
+		PubsubSendRPCView,
-	APIRequestDurationView,
+		PubsubDropRPCView,
-	VMFlushCopyCountView,
+		APIRequestDurationView,
-	VMFlushCopyDurationView,
+		VMFlushCopyCountView,
-},
+		VMFlushCopyDurationView,
-	rpcmetrics.DefaultViews...)
+	}
+	views = append(views, blockstore.DefaultViews...)
+	views = append(views, rpcmetrics.DefaultViews...)
+	return views
+}()
 
 // SinceInMilliseconds returns the duration of time since the provide time as a float64.
 func SinceInMilliseconds(startTime time.Time) float64 {

node/builder.go

@@ -145,7 +145,7 @@ const (
 	HeadMetricsKey
 	SettlePaymentChannelsKey
 	RunPeerTaggerKey
-	SetupFallbackBlockstoreKey
+	SetupFallbackBlockstoresKey
 
 	SetApiEndpointKey
 
@@ -590,12 +590,15 @@ func Repo(r repo.Repo) Option {
 			Override(new(repo.LockedRepo), modules.LockedRepo(lr)), // module handles closing
 
 			Override(new(dtypes.MetadataDS), modules.Datastore),
-			Override(new(dtypes.ChainRawBlockstore), modules.ChainRawBlockstore),
+			Override(new(dtypes.UniversalBlockstore), modules.UniversalBlockstore),
-			Override(new(dtypes.ChainBlockstore), From(new(dtypes.ChainRawBlockstore))),
+			Override(new(dtypes.ChainBlockstore), modules.ChainBlockstore),
+			Override(new(dtypes.StateBlockstore), modules.StateBlockstore),
+			Override(new(dtypes.ExposedBlockstore), From(new(dtypes.UniversalBlockstore))),
 
 			If(os.Getenv("LOTUS_ENABLE_CHAINSTORE_FALLBACK") == "1",
 				Override(new(dtypes.ChainBlockstore), modules.FallbackChainBlockstore),
-				Override(SetupFallbackBlockstoreKey, modules.SetupFallbackBlockstore),
+				Override(new(dtypes.StateBlockstore), modules.FallbackStateBlockstore),
+				Override(SetupFallbackBlockstoresKey, modules.InitFallbackBlockstores),
 			),
 
 			Override(new(dtypes.ClientImportMgr), modules.ClientImportMgr),

node/impl/full/chain.go

@@ -35,6 +35,7 @@ import (
 	"github.com/filecoin-project/lotus/chain/store"
 	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/chain/vm"
+	"github.com/filecoin-project/lotus/node/modules/dtypes"
 )
 
 var log = logging.Logger("fullnode")
@@ -57,6 +58,11 @@ type ChainModule struct {
 	fx.In
 
 	Chain *store.ChainStore
+
+	// ExposedBlockstore is the global monolith blockstore that is safe to
+	// expose externally. In the future, this will be segregated into two
+	// blockstores.
+	ExposedBlockstore dtypes.ExposedBlockstore
 }
 
 var _ ChainModuleAPI = (*ChainModule)(nil)
@@ -68,6 +74,11 @@ type ChainAPI struct {
 	ChainModuleAPI
 
 	Chain *store.ChainStore
+
+	// ExposedBlockstore is the global monolith blockstore that is safe to
+	// expose externally. In the future, this will be segregated into two
+	// blockstores.
+	ExposedBlockstore dtypes.ExposedBlockstore
 }
 
 func (m *ChainModule) ChainNotify(ctx context.Context) (<-chan []*api.HeadChange, error) {
@@ -212,7 +223,7 @@ func (m *ChainModule) ChainGetTipSetByHeight(ctx context.Context, h abi.ChainEpo
 }
 
 func (m *ChainModule) ChainReadObj(ctx context.Context, obj cid.Cid) ([]byte, error) {
-	blk, err := m.Chain.Blockstore().Get(obj)
+	blk, err := m.ExposedBlockstore.Get(obj)
 	if err != nil {
 		return nil, xerrors.Errorf("blockstore get: %w", err)
 	}
@@ -221,15 +232,15 @@ func (m *ChainModule) ChainReadObj(ctx context.Context, obj cid.Cid) ([]byte, er
 }
 
 func (a *ChainAPI) ChainDeleteObj(ctx context.Context, obj cid.Cid) error {
-	return a.Chain.Blockstore().DeleteBlock(obj)
+	return a.ExposedBlockstore.DeleteBlock(obj)
 }
 
 func (m *ChainModule) ChainHasObj(ctx context.Context, obj cid.Cid) (bool, error) {
-	return m.Chain.Blockstore().Has(obj)
+	return m.ExposedBlockstore.Has(obj)
 }
 
 func (a *ChainAPI) ChainStatObj(ctx context.Context, obj cid.Cid, base cid.Cid) (api.ObjStat, error) {
-	bs := a.Chain.Blockstore()
+	bs := a.ExposedBlockstore
 	bsvc := blockservice.New(bs, offline.Exchange(bs))
 
 	dag := merkledag.NewDAGService(bsvc)
@@ -514,7 +525,7 @@ func (a *ChainAPI) ChainGetNode(ctx context.Context, p string) (*api.IpldObject,
 		return nil, xerrors.Errorf("parsing path: %w", err)
 	}
 
-	bs := a.Chain.Blockstore()
+	bs := a.ExposedBlockstore
 	bsvc := blockservice.New(bs, offline.Exchange(bs))
 
 	dag := merkledag.NewDAGService(bsvc)

node/impl/full/state.go

@@ -97,7 +97,7 @@ func (a *StateAPI) StateMinerSectors(ctx context.Context, addr address.Address,
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -111,7 +111,7 @@ func (a *StateAPI) StateMinerActiveSectors(ctx context.Context, maddr address.Ad
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -135,7 +135,7 @@ func (m *StateModule) StateMinerInfo(ctx context.Context, actor address.Address,
 		return miner.MinerInfo{}, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(m.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(m.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return miner.MinerInfo{}, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -153,7 +153,7 @@ func (a *StateAPI) StateMinerDeadlines(ctx context.Context, m address.Address, t
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -192,7 +192,7 @@ func (a *StateAPI) StateMinerPartitions(ctx context.Context, m address.Address,
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -253,7 +253,7 @@ func (m *StateModule) StateMinerProvingDeadline(ctx context.Context, addr addres
 		return nil, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(m.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(m.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -272,7 +272,7 @@ func (a *StateAPI) StateMinerFaults(ctx context.Context, addr address.Address, t
 		return bitfield.BitField{}, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return bitfield.BitField{}, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -329,7 +329,7 @@ func (a *StateAPI) StateMinerRecoveries(ctx context.Context, addr address.Addres
 		return bitfield.BitField{}, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return bitfield.BitField{}, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -461,7 +461,7 @@ func (a *StateAPI) StateReadState(ctx context.Context, actor address.Address, ts
 		return nil, xerrors.Errorf("getting actor: %w", err)
 	}
 
-	blk, err := a.Chain.Blockstore().Get(act.Head)
+	blk, err := a.Chain.StateBlockstore().Get(act.Head)
 	if err != nil {
 		return nil, xerrors.Errorf("getting actor head: %w", err)
 	}
@@ -707,7 +707,7 @@ func (m *StateModule) StateMarketStorageDeal(ctx context.Context, dealId abi.Dea
 }
 
 func (a *StateAPI) StateChangedActors(ctx context.Context, old cid.Cid, new cid.Cid) (map[string]types.Actor, error) {
-	store := a.Chain.Store(ctx)
+	store := a.Chain.ActorStore(ctx)
 
 	oldTree, err := state.LoadStateTree(store, old)
 	if err != nil {
@@ -727,7 +727,7 @@ func (a *StateAPI) StateMinerSectorCount(ctx context.Context, addr address.Addre
 	if err != nil {
 		return api.MinerSectors{}, err
 	}
-	mas, err := miner.Load(a.Chain.Store(ctx), act)
+	mas, err := miner.Load(a.Chain.ActorStore(ctx), act)
 	if err != nil {
 		return api.MinerSectors{}, err
 	}
@@ -792,7 +792,7 @@ func (a *StateAPI) StateSectorExpiration(ctx context.Context, maddr address.Addr
 	if err != nil {
 		return nil, err
 	}
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, err
 	}
@@ -804,7 +804,7 @@ func (a *StateAPI) StateSectorPartition(ctx context.Context, maddr address.Addre
 	if err != nil {
 		return nil, err
 	}
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, err
 	}
@@ -890,7 +890,7 @@ func (m *StateModule) MsigGetAvailableBalance(ctx context.Context, addr address.
 	if err != nil {
 		return types.EmptyInt, xerrors.Errorf("failed to load multisig actor: %w", err)
 	}
-	msas, err := multisig.Load(m.Chain.Store(ctx), act)
+	msas, err := multisig.Load(m.Chain.ActorStore(ctx), act)
 	if err != nil {
 		return types.EmptyInt, xerrors.Errorf("failed to load multisig actor state: %w", err)
 	}
@@ -912,7 +912,7 @@ func (a *StateAPI) MsigGetVestingSchedule(ctx context.Context, addr address.Addr
 		return api.EmptyVesting, xerrors.Errorf("failed to load multisig actor: %w", err)
 	}
 
-	msas, err := multisig.Load(a.Chain.Store(ctx), act)
+	msas, err := multisig.Load(a.Chain.ActorStore(ctx), act)
 	if err != nil {
 		return api.EmptyVesting, xerrors.Errorf("failed to load multisig actor state: %w", err)
 	}
@@ -961,7 +961,7 @@ func (m *StateModule) MsigGetVested(ctx context.Context, addr address.Address, s
 		return types.EmptyInt, xerrors.Errorf("failed to load multisig actor at end epoch: %w", err)
 	}
 
-	msas, err := multisig.Load(m.Chain.Store(ctx), act)
+	msas, err := multisig.Load(m.Chain.ActorStore(ctx), act)
 	if err != nil {
 		return types.EmptyInt, xerrors.Errorf("failed to load multisig actor state: %w", err)
 	}
@@ -989,7 +989,7 @@ func (m *StateModule) MsigGetPending(ctx context.Context, addr address.Address,
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load multisig actor: %w", err)
 	}
-	msas, err := multisig.Load(m.Chain.Store(ctx), act)
+	msas, err := multisig.Load(m.Chain.ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load multisig actor state: %w", err)
 	}
@@ -1032,7 +1032,7 @@ func (a *StateAPI) StateMinerPreCommitDepositForPower(ctx context.Context, maddr
 		return types.EmptyInt, xerrors.Errorf("failed to get resolve size: %w", err)
 	}
 
-	store := a.Chain.Store(ctx)
+	store := a.Chain.ActorStore(ctx)
 
 	var sectorWeight abi.StoragePower
 	if act, err := state.GetActor(market.Address); err != nil {
@@ -1093,7 +1093,7 @@ func (a *StateAPI) StateMinerInitialPledgeCollateral(ctx context.Context, maddr
 		return types.EmptyInt, xerrors.Errorf("failed to get resolve size: %w", err)
 	}
 
-	store := a.Chain.Store(ctx)
+	store := a.Chain.ActorStore(ctx)
 
 	var sectorWeight abi.StoragePower
 	if act, err := state.GetActor(market.Address); err != nil {
@@ -1164,7 +1164,7 @@ func (a *StateAPI) StateMinerAvailableBalance(ctx context.Context, maddr address
 		return types.EmptyInt, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return types.EmptyInt, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -1193,7 +1193,7 @@ func (a *StateAPI) StateMinerSectorAllocated(ctx context.Context, maddr address.
 		return false, xerrors.Errorf("failed to load miner actor: %w", err)
 	}
 
-	mas, err := miner.Load(a.StateManager.ChainStore().Store(ctx), act)
+	mas, err := miner.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return false, xerrors.Errorf("failed to load miner actor state: %w", err)
 	}
@@ -1216,7 +1216,7 @@ func (a *StateAPI) StateVerifierStatus(ctx context.Context, addr address.Address
 		return nil, err
 	}
 
-	vrs, err := verifreg.Load(a.StateManager.ChainStore().Store(ctx), act)
+	vrs, err := verifreg.Load(a.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load verified registry state: %w", err)
 	}
@@ -1247,7 +1247,7 @@ func (m *StateModule) StateVerifiedClientStatus(ctx context.Context, addr addres
 		return nil, err
 	}
 
-	vrs, err := verifreg.Load(m.StateManager.ChainStore().Store(ctx), act)
+	vrs, err := verifreg.Load(m.StateManager.ChainStore().ActorStore(ctx), act)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to load verified registry state: %w", err)
 	}
@@ -1269,7 +1269,7 @@ func (a *StateAPI) StateVerifiedRegistryRootKey(ctx context.Context, tsk types.T
 		return address.Undef, err
 	}
 
-	vst, err := verifreg.Load(a.StateManager.ChainStore().Store(ctx), vact)
+	vst, err := verifreg.Load(a.StateManager.ChainStore().ActorStore(ctx), vact)
 	if err != nil {
 		return address.Undef, err
 	}
@@ -1298,12 +1298,12 @@ func (m *StateModule) StateDealProviderCollateralBounds(ctx context.Context, siz
 		return api.DealCollateralBounds{}, xerrors.Errorf("failed to load reward actor: %w", err)
 	}
 
-	pst, err := power.Load(m.StateManager.ChainStore().Store(ctx), pact)
+	pst, err := power.Load(m.StateManager.ChainStore().ActorStore(ctx), pact)
 	if err != nil {
 		return api.DealCollateralBounds{}, xerrors.Errorf("failed to load power actor state: %w", err)
 	}
 
-	rst, err := reward.Load(m.StateManager.ChainStore().Store(ctx), ract)
+	rst, err := reward.Load(m.StateManager.ChainStore().ActorStore(ctx), ract)
 	if err != nil {
 		return api.DealCollateralBounds{}, xerrors.Errorf("failed to load reward actor state: %w", err)
 	}

node/modules/blockstore.go

@@ -0,0 +1,65 @@
+package modules
+
+import (
+	"context"
+	"io"
+
+	bstore "github.com/ipfs/go-ipfs-blockstore"
+	"go.uber.org/fx"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/blockstore"
+	"github.com/filecoin-project/lotus/node/modules/dtypes"
+	"github.com/filecoin-project/lotus/node/modules/helpers"
+	"github.com/filecoin-project/lotus/node/repo"
+)
+
+// UniversalBlockstore returns a single universal blockstore that stores both
+// chain data and state data.
+func UniversalBlockstore(lc fx.Lifecycle, mctx helpers.MetricsCtx, r repo.LockedRepo) (dtypes.UniversalBlockstore, error) {
+	bs, err := r.Blockstore(helpers.LifecycleCtx(mctx, lc), repo.UniversalBlockstore)
+	if err != nil {
+		return nil, err
+	}
+	if c, ok := bs.(io.Closer); ok {
+		lc.Append(fx.Hook{
+			OnStop: func(_ context.Context) error {
+				return c.Close()
+			},
+		})
+	}
+	return bs, err
+}
+
+// StateBlockstore is a hook to overlay caches for state objects, or in the
+// future, to segregate the universal blockstore into different physical state
+// and chain stores.
+func StateBlockstore(lc fx.Lifecycle, mctx helpers.MetricsCtx, bs dtypes.UniversalBlockstore) (dtypes.StateBlockstore, error) {
+	return bs, nil
+}
+
+// ChainBlockstore is a hook to overlay caches for state objects, or in the
+// future, to segregate the universal blockstore into different physical state
+// and chain stores.
+func ChainBlockstore(lc fx.Lifecycle, mctx helpers.MetricsCtx, bs dtypes.UniversalBlockstore) (dtypes.ChainBlockstore, error) {
+	return bs, nil
+}
+
+func FallbackChainBlockstore(cbs dtypes.ChainBlockstore) dtypes.ChainBlockstore {
+	return &blockstore.FallbackStore{Blockstore: cbs}
+}
+
+func FallbackStateBlockstore(sbs dtypes.StateBlockstore) dtypes.StateBlockstore {
+	return &blockstore.FallbackStore{Blockstore: sbs}
+}
+
+func InitFallbackBlockstores(cbs dtypes.ChainBlockstore, sbs dtypes.StateBlockstore, rem dtypes.ChainBitswap) error {
+	for _, bs := range []bstore.Blockstore{cbs, sbs} {
+		if fbs, ok := bs.(*blockstore.FallbackStore); ok {
+			fbs.SetFallback(rem.GetBlock)
+			continue
+		}
+		return xerrors.Errorf("expected a FallbackStore")
+	}
+	return nil
+}

node/modules/chain.go

@@ -1,25 +1,18 @@
 package modules
 
 import (
-	"bytes"
 	"context"
-	"os"
 	"time"
 
 	"github.com/ipfs/go-bitswap"
 	"github.com/ipfs/go-bitswap/network"
 	"github.com/ipfs/go-blockservice"
-	"github.com/ipfs/go-datastore"
-	"github.com/ipld/go-car"
 	"github.com/libp2p/go-libp2p-core/host"
 	"github.com/libp2p/go-libp2p-core/routing"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"go.uber.org/fx"
 	"golang.org/x/xerrors"
 
-	"github.com/filecoin-project/lotus/extern/sector-storage/ffiwrapper"
-	"github.com/filecoin-project/lotus/journal"
-
 	"github.com/filecoin-project/lotus/blockstore"
 	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain"
@@ -29,14 +22,15 @@ import (
 	"github.com/filecoin-project/lotus/chain/messagepool"
 	"github.com/filecoin-project/lotus/chain/stmgr"
 	"github.com/filecoin-project/lotus/chain/store"
-	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/chain/vm"
+	"github.com/filecoin-project/lotus/extern/sector-storage/ffiwrapper"
+	"github.com/filecoin-project/lotus/journal"
 	"github.com/filecoin-project/lotus/node/modules/dtypes"
 	"github.com/filecoin-project/lotus/node/modules/helpers"
-	"github.com/filecoin-project/lotus/node/repo"
 )
 
-func ChainBitswap(mctx helpers.MetricsCtx, lc fx.Lifecycle, host host.Host, rt routing.Routing, bs dtypes.ChainBlockstore) dtypes.ChainBitswap {
+// ChainBitswap uses a blockstore that bypasses all caches.
+func ChainBitswap(mctx helpers.MetricsCtx, lc fx.Lifecycle, host host.Host, rt routing.Routing, bs dtypes.ExposedBlockstore) dtypes.ChainBitswap {
 	// prefix protocol for chain bitswap
 	// (so bitswap uses /chain/ipfs/bitswap/1.0.0 internally for chain sync stuff)
 	bitswapNetwork := network.NewFromIpfsHost(host, rt, network.Prefix("/chain"))
@@ -60,6 +54,10 @@ func ChainBitswap(mctx helpers.MetricsCtx, lc fx.Lifecycle, host host.Host, rt r
 	return exch
 }
 
+func ChainBlockService(bs dtypes.ExposedBlockstore, rem dtypes.ChainBitswap) dtypes.ChainBlockService {
+	return blockservice.New(bs, rem)
+}
+
 func MessagePool(lc fx.Lifecycle, sm *stmgr.StateManager, ps *pubsub.PubSub, ds dtypes.MetadataDS, nn dtypes.NetworkName, j journal.Journal) (*messagepool.MessagePool, error) {
 	mpp := messagepool.NewProvider(sm, ps)
 	mp, err := messagepool.New(mpp, ds, nn, j)
@@ -74,43 +72,8 @@ func MessagePool(lc fx.Lifecycle, sm *stmgr.StateManager, ps *pubsub.PubSub, ds
 	return mp, nil
 }
 
-func ChainRawBlockstore(lc fx.Lifecycle, mctx helpers.MetricsCtx, r repo.LockedRepo) (dtypes.ChainRawBlockstore, error) {
+func ChainStore(lc fx.Lifecycle, cbs dtypes.ChainBlockstore, sbs dtypes.StateBlockstore, ds dtypes.MetadataDS, syscalls vm.SyscallBuilder, j journal.Journal) *store.ChainStore {
-	bs, err := r.Blockstore(helpers.LifecycleCtx(mctx, lc), repo.BlockstoreChain)
+	chain := store.NewChainStore(cbs, sbs, ds, syscalls, j)
-	if err != nil {
-		return nil, err
-	}
-
-	// TODO potentially replace this cached blockstore by a CBOR cache.
-	cbs, err := blockstore.CachedBlockstore(helpers.LifecycleCtx(mctx, lc), bs, blockstore.DefaultCacheOpts())
-	if err != nil {
-		return nil, err
-	}
-
-	return cbs, nil
-}
-
-func ChainBlockService(bs dtypes.ChainRawBlockstore, rem dtypes.ChainBitswap) dtypes.ChainBlockService {
-	return blockservice.New(bs, rem)
-}
-
-func FallbackChainBlockstore(rbs dtypes.ChainRawBlockstore) dtypes.ChainBlockstore {
-	return &blockstore.FallbackStore{
-		Blockstore: rbs,
-	}
-}
-
-func SetupFallbackBlockstore(cbs dtypes.ChainBlockstore, rem dtypes.ChainBitswap) error {
-	fbs, ok := cbs.(*blockstore.FallbackStore)
-	if !ok {
-		return xerrors.Errorf("expected a FallbackStore")
-	}
-
-	fbs.SetFallback(rem.GetBlock)
-	return nil
-}
-
-func ChainStore(lc fx.Lifecycle, bs dtypes.ChainBlockstore, lbs dtypes.ChainRawBlockstore, ds dtypes.MetadataDS, syscalls vm.SyscallBuilder, j journal.Journal) *store.ChainStore {
-	chain := store.NewChainStore(bs, lbs, ds, syscalls, j)
 
 	if err := chain.Load(); err != nil {
 		log.Warnf("loading chain state from disk: %s", err)
@@ -125,65 +88,6 @@ func ChainStore(lc fx.Lifecycle, bs dtypes.ChainBlockstore, lbs dtypes.ChainRawB
 	return chain
 }
 
-func ErrorGenesis() Genesis {
-	return func() (header *types.BlockHeader, e error) {
-		return nil, xerrors.New("No genesis block provided, provide the file with 'lotus daemon --genesis=[genesis file]'")
-	}
-}
-
-func LoadGenesis(genBytes []byte) func(dtypes.ChainBlockstore) Genesis {
-	return func(bs dtypes.ChainBlockstore) Genesis {
-		return func() (header *types.BlockHeader, e error) {
-			c, err := car.LoadCar(bs, bytes.NewReader(genBytes))
-			if err != nil {
-				return nil, xerrors.Errorf("loading genesis car file failed: %w", err)
-			}
-			if len(c.Roots) != 1 {
-				return nil, xerrors.New("expected genesis file to have one root")
-			}
-			root, err := bs.Get(c.Roots[0])
-			if err != nil {
-				return nil, err
-			}
-
-			h, err := types.DecodeBlock(root.RawData())
-			if err != nil {
-				return nil, xerrors.Errorf("decoding block failed: %w", err)
-			}
-			return h, nil
-		}
-	}
-}
-
-func DoSetGenesis(_ dtypes.AfterGenesisSet) {}
-
-func SetGenesis(cs *store.ChainStore, g Genesis) (dtypes.AfterGenesisSet, error) {
-	genFromRepo, err := cs.GetGenesis()
-	if err == nil {
-		if os.Getenv("LOTUS_SKIP_GENESIS_CHECK") != "_yes_" {
-			expectedGenesis, err := g()
-			if err != nil {
-				return dtypes.AfterGenesisSet{}, xerrors.Errorf("getting expected genesis failed: %w", err)
-			}
-
-			if genFromRepo.Cid() != expectedGenesis.Cid() {
-				return dtypes.AfterGenesisSet{}, xerrors.Errorf("genesis in the repo is not the one expected by this version of Lotus!")
-			}
-		}
-		return dtypes.AfterGenesisSet{}, nil // already set, noop
-	}
-	if err != datastore.ErrNotFound {
-		return dtypes.AfterGenesisSet{}, xerrors.Errorf("getting genesis block failed: %w", err)
-	}
-
-	genesis, err := g()
-	if err != nil {
-		return dtypes.AfterGenesisSet{}, xerrors.Errorf("genesis func failed: %w", err)
-	}
-
-	return dtypes.AfterGenesisSet{}, cs.SetGenesis(genesis)
-}
-
 func NetworkName(mctx helpers.MetricsCtx, lc fx.Lifecycle, cs *store.ChainStore, us stmgr.UpgradeSchedule, _ dtypes.AfterGenesisSet) (dtypes.NetworkName, error) {
 	if !build.Devnet {
 		return "testnetnet", nil

node/modules/client.go

@@ -83,7 +83,7 @@ func ClientMultiDatastore(lc fx.Lifecycle, mctx helpers.MetricsCtx, r repo.Locke
 	ctx := helpers.LifecycleCtx(mctx, lc)
 	ds, err := r.Datastore(ctx, "/client")
 	if err != nil {
-		return nil, xerrors.Errorf("getting datastore out of reop: %w", err)
+		return nil, xerrors.Errorf("getting datastore out of repo: %w", err)
 	}
 
 	mds, err := multistore.NewMultiDstore(ds)

node/modules/dtypes/storage.go

@@ -19,19 +19,41 @@ import (
 	"github.com/filecoin-project/lotus/node/repo/retrievalstoremgr"
 )
 
-// MetadataDS stores metadata
+// MetadataDS stores metadata. By default it's namespaced under /metadata in
-// dy default it's namespaced under /metadata in main repo datastore
+// main repo datastore.
 type MetadataDS datastore.Batching
 
-type ChainRawBlockstore blockstore.Blockstore
+type (
-type ChainBlockstore blockstore.Blockstore // optionally bitswap backed
+	// UniversalBlockstore is the cold blockstore.
+	UniversalBlockstore blockstore.Blockstore
+
+	// ChainBlockstore is a blockstore to store chain data (tipsets, blocks,
+	// messages). It is physically backed by the BareMonolithBlockstore, but it
+	// has a cache on top that is specially tuned for chain data access
+	// patterns.
+	ChainBlockstore blockstore.Blockstore
+
+	// StateBlockstore is a blockstore to store state data (state tree). It is
+	// physically backed by the BareMonolithBlockstore, but it has a cache on
+	// top that is specially tuned for state data access patterns.
+	StateBlockstore blockstore.Blockstore
+
+	// ExposedBlockstore is a blockstore that interfaces directly with the
+	// network or with users, from which queries are served, and where incoming
+	// data is deposited. For security reasons, this store is disconnected from
+	// any internal caches. If blocks are added to this store in a way that
+	// could render caches dirty (e.g. a block is added when an existence cache
+	// holds a 'false' for that block), the process should signal so by calling
+	// blockstore.AllCaches.Dirty(cid).
+	ExposedBlockstore blockstore.Blockstore
+)
 
 type ChainBitswap exchange.Interface
 type ChainBlockService bserv.BlockService
 
 type ClientMultiDstore *multistore.MultiStore
 type ClientImportMgr *importmgr.Mgr
-type ClientBlockstore blockstore.Blockstore
+type ClientBlockstore blockstore.BasicBlockstore
 type ClientDealStore *statestore.StateStore
 type ClientRequestValidator *requestvalidation.UnifiedRequestValidator
 type ClientDatastore datastore.Batching
@@ -50,6 +72,6 @@ type ProviderRequestValidator *requestvalidation.UnifiedRequestValidator
 type ProviderDataTransfer datatransfer.Manager
 
 type StagingDAG format.DAGService
-type StagingBlockstore blockstore.Blockstore
+type StagingBlockstore blockstore.BasicBlockstore
 type StagingGraphsync graphsync.GraphExchange
 type StagingMultiDstore *multistore.MultiStore

node/modules/genesis.go

@@ -0,0 +1,73 @@
+package modules
+
+import (
+	"bytes"
+	"os"
+
+	"github.com/ipfs/go-datastore"
+	"github.com/ipld/go-car"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/chain/store"
+	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/filecoin-project/lotus/node/modules/dtypes"
+)
+
+func ErrorGenesis() Genesis {
+	return func() (header *types.BlockHeader, e error) {
+		return nil, xerrors.New("No genesis block provided, provide the file with 'lotus daemon --genesis=[genesis file]'")
+	}
+}
+
+func LoadGenesis(genBytes []byte) func(dtypes.ChainBlockstore) Genesis {
+	return func(bs dtypes.ChainBlockstore) Genesis {
+		return func() (header *types.BlockHeader, e error) {
+			c, err := car.LoadCar(bs, bytes.NewReader(genBytes))
+			if err != nil {
+				return nil, xerrors.Errorf("loading genesis car file failed: %w", err)
+			}
+			if len(c.Roots) != 1 {
+				return nil, xerrors.New("expected genesis file to have one root")
+			}
+			root, err := bs.Get(c.Roots[0])
+			if err != nil {
+				return nil, err
+			}
+
+			h, err := types.DecodeBlock(root.RawData())
+			if err != nil {
+				return nil, xerrors.Errorf("decoding block failed: %w", err)
+			}
+			return h, nil
+		}
+	}
+}
+
+func DoSetGenesis(_ dtypes.AfterGenesisSet) {}
+
+func SetGenesis(cs *store.ChainStore, g Genesis) (dtypes.AfterGenesisSet, error) {
+	genFromRepo, err := cs.GetGenesis()
+	if err == nil {
+		if os.Getenv("LOTUS_SKIP_GENESIS_CHECK") != "_yes_" {
+			expectedGenesis, err := g()
+			if err != nil {
+				return dtypes.AfterGenesisSet{}, xerrors.Errorf("getting expected genesis failed: %w", err)
+			}
+
+			if genFromRepo.Cid() != expectedGenesis.Cid() {
+				return dtypes.AfterGenesisSet{}, xerrors.Errorf("genesis in the repo is not the one expected by this version of Lotus!")
+			}
+		}
+		return dtypes.AfterGenesisSet{}, nil // already set, noop
+	}
+	if err != datastore.ErrNotFound {
+		return dtypes.AfterGenesisSet{}, xerrors.Errorf("getting genesis block failed: %w", err)
+	}
+
+	genesis, err := g()
+	if err != nil {
+		return dtypes.AfterGenesisSet{}, xerrors.Errorf("genesis func failed: %w", err)
+	}
+
+	return dtypes.AfterGenesisSet{}, cs.SetGenesis(genesis)
+}

node/modules/graphsync.go

@@ -14,8 +14,8 @@ import (
 )
 
 // Graphsync creates a graphsync instance from the given loader and storer
-func Graphsync(parallelTransfers uint64) func(mctx helpers.MetricsCtx, lc fx.Lifecycle, r repo.LockedRepo, clientBs dtypes.ClientBlockstore, chainBs dtypes.ChainBlockstore, h host.Host) (dtypes.Graphsync, error) {
+func Graphsync(parallelTransfers uint64) func(mctx helpers.MetricsCtx, lc fx.Lifecycle, r repo.LockedRepo, clientBs dtypes.ClientBlockstore, chainBs dtypes.ExposedBlockstore, h host.Host) (dtypes.Graphsync, error) {
-	return func(mctx helpers.MetricsCtx, lc fx.Lifecycle, r repo.LockedRepo, clientBs dtypes.ClientBlockstore, chainBs dtypes.ChainBlockstore, h host.Host) (dtypes.Graphsync, error) {
+	return func(mctx helpers.MetricsCtx, lc fx.Lifecycle, r repo.LockedRepo, clientBs dtypes.ClientBlockstore, chainBs dtypes.ExposedBlockstore, h host.Host) (dtypes.Graphsync, error) {
 		graphsyncNetwork := gsnet.NewFromLibp2pHost(h)
 		loader := storeutil.LoaderForBlockstore(clientBs)
 		storer := storeutil.StorerForBlockstore(clientBs)

node/modules/ipfsclient.go

@@ -18,7 +18,7 @@ import (
 func IpfsClientBlockstore(ipfsMaddr string, onlineMode bool) func(helpers.MetricsCtx, fx.Lifecycle, dtypes.ClientImportMgr) (dtypes.ClientBlockstore, error) {
 	return func(mctx helpers.MetricsCtx, lc fx.Lifecycle, localStore dtypes.ClientImportMgr) (dtypes.ClientBlockstore, error) {
 		var err error
-		var ipfsbs blockstore.Blockstore
+		var ipfsbs blockstore.BasicBlockstore
 		if ipfsMaddr != "" {
 			var ma multiaddr.Multiaddr
 			ma, err = multiaddr.NewMultiaddr(ipfsMaddr)

node/repo/blockstore_opts.go

@@ -5,10 +5,6 @@ import badgerbs "github.com/filecoin-project/lotus/blockstore/badger"
 // BadgerBlockstoreOptions returns the badger options to apply for the provided
 // domain.
 func BadgerBlockstoreOptions(domain BlockstoreDomain, path string, readonly bool) (badgerbs.Options, error) {
-	if domain != BlockstoreChain {
-		return badgerbs.Options{}, ErrInvalidBlockstoreDomain
-	}
-
 	opts := badgerbs.DefaultOptions(path)
 
 	// Due to legacy usage of blockstore.Blockstore, over a datastore, all

node/repo/fsrepo.go

@@ -13,7 +13,7 @@ import (
 	"sync"
 
 	"github.com/BurntSushi/toml"
-	"github.com/filecoin-project/lotus/blockstore"
+
 	"github.com/ipfs/go-datastore"
 	fslock "github.com/ipfs/go-fs-lock"
 	logging "github.com/ipfs/go-log/v2"
@@ -22,7 +22,7 @@ import (
 	"github.com/multiformats/go-multiaddr"
 	"golang.org/x/xerrors"
 
-	lblockstore "github.com/filecoin-project/lotus/blockstore"
+	"github.com/filecoin-project/lotus/blockstore"
 	badgerbs "github.com/filecoin-project/lotus/blockstore/badger"
 	"github.com/filecoin-project/lotus/extern/sector-storage/fsutil"
 	"github.com/filecoin-project/lotus/extern/sector-storage/stores"
@@ -264,11 +264,18 @@ type fsLockedRepo struct {
 	bs     blockstore.Blockstore
 	bsErr  error
 	bsOnce sync.Once
+	ssPath string
+	ssErr  error
+	ssOnce sync.Once
 
 	storageLk sync.Mutex
 	configLk  sync.Mutex
 }
 
+func (fsr *fsLockedRepo) Readonly() bool {
+	return fsr.readonly
+}
+
 func (fsr *fsLockedRepo) Path() string {
 	return fsr.path
 }
@@ -301,7 +308,7 @@ func (fsr *fsLockedRepo) Close() error {
 
 // Blockstore returns a blockstore for the provided data domain.
 func (fsr *fsLockedRepo) Blockstore(ctx context.Context, domain BlockstoreDomain) (blockstore.Blockstore, error) {
-	if domain != BlockstoreChain {
+	if domain != UniversalBlockstore {
 		return nil, ErrInvalidBlockstoreDomain
 	}
 
@@ -325,12 +332,27 @@ func (fsr *fsLockedRepo) Blockstore(ctx context.Context, domain BlockstoreDomain
 			fsr.bsErr = err
 			return
 		}
-		fsr.bs = lblockstore.WrapIDStore(bs)
+		fsr.bs = blockstore.WrapIDStore(bs)
 	})
 
 	return fsr.bs, fsr.bsErr
 }
 
+func (fsr *fsLockedRepo) SplitstorePath() (string, error) {
+	fsr.ssOnce.Do(func() {
+		path := fsr.join(filepath.Join(fsDatastore, "splitstore"))
+
+		if err := os.MkdirAll(path, 0755); err != nil {
+			fsr.ssErr = err
+			return
+		}
+
+		fsr.ssPath = path
+	})
+
+	return fsr.ssPath, fsr.ssErr
+}
+
 // join joins path elements with fsr.path
 func (fsr *fsLockedRepo) join(paths ...string) string {
 	return filepath.Join(append([]string{fsr.path}, paths...)...)

node/repo/importmgr/mgr.go

@@ -16,7 +16,7 @@ type Mgr struct {
 	mds *multistore.MultiStore
 	ds  datastore.Batching
 
-	Blockstore blockstore.Blockstore
+	Blockstore blockstore.BasicBlockstore
 }
 
 type Label string

node/repo/interface.go

@@ -4,10 +4,10 @@ import (
 	"context"
 	"errors"
 
-	"github.com/filecoin-project/lotus/blockstore"
 	"github.com/ipfs/go-datastore"
 	"github.com/multiformats/go-multiaddr"
 
+	"github.com/filecoin-project/lotus/blockstore"
 	"github.com/filecoin-project/lotus/extern/sector-storage/fsutil"
 	"github.com/filecoin-project/lotus/extern/sector-storage/stores"
 
@@ -18,11 +18,11 @@ import (
 type BlockstoreDomain string
 
 const (
-	// BlockstoreChain represents the blockstore domain for chain data.
+	// UniversalBlockstore represents the blockstore domain for all data.
 	// Right now, this includes chain objects (tipsets, blocks, messages), as
 	// well as state. In the future, they may get segregated into different
 	// domains.
-	BlockstoreChain = BlockstoreDomain("chain")
+	UniversalBlockstore = BlockstoreDomain("universal")
 )
 
 var (
@@ -63,6 +63,9 @@ type LockedRepo interface {
 	// the lifecycle.
 	Blockstore(ctx context.Context, domain BlockstoreDomain) (blockstore.Blockstore, error)
 
+	// SplitstorePath returns the path for the SplitStore
+	SplitstorePath() (string, error)
+
 	// Returns config in this repo
 	Config() (interface{}, error)
 	SetConfig(func(interface{})) error
@@ -84,4 +87,7 @@ type LockedRepo interface {
 
 	// Path returns absolute path of the repo
 	Path() string
+
+	// Readonly returns true if the repo is readonly
+	Readonly() bool
 }

node/repo/memrepo.go

@@ -201,6 +201,10 @@ func (mem *MemRepo) Lock(t RepoType) (LockedRepo, error) {
 	}, nil
 }
 
+func (lmem *lockedMemRepo) Readonly() bool {
+	return false
+}
+
 func (lmem *lockedMemRepo) checkToken() error {
 	lmem.RLock()
 	defer lmem.RUnlock()
@@ -246,12 +250,16 @@ func (lmem *lockedMemRepo) Datastore(_ context.Context, ns string) (datastore.Ba
 }
 
 func (lmem *lockedMemRepo) Blockstore(ctx context.Context, domain BlockstoreDomain) (blockstore.Blockstore, error) {
-	if domain != BlockstoreChain {
+	if domain != UniversalBlockstore {
 		return nil, ErrInvalidBlockstoreDomain
 	}
 	return lmem.mem.blockstore, nil
 }
 
+func (lmem *lockedMemRepo) SplitstorePath() (string, error) {
+	return ioutil.TempDir("", "splitstore.*")
+}
+
 func (lmem *lockedMemRepo) ListDatastores(ns string) ([]int64, error) {
 	return nil, nil
 }

node/repo/retrievalstoremgr/retrievalstoremgr.go

@@ -73,13 +73,13 @@ func (mrs *multiStoreRetrievalStore) DAGService() ipldformat.DAGService {
 
 // BlockstoreRetrievalStoreManager manages a single blockstore as if it were multiple stores
 type BlockstoreRetrievalStoreManager struct {
-	bs blockstore.Blockstore
+	bs blockstore.BasicBlockstore
 }
 
 var _ RetrievalStoreManager = &BlockstoreRetrievalStoreManager{}
 
 // NewBlockstoreRetrievalStoreManager returns a new blockstore based RetrievalStoreManager
-func NewBlockstoreRetrievalStoreManager(bs blockstore.Blockstore) RetrievalStoreManager {
+func NewBlockstoreRetrievalStoreManager(bs blockstore.BasicBlockstore) RetrievalStoreManager {
 	return &BlockstoreRetrievalStoreManager{
 		bs: bs,
 	}