fix(share/eds): dagstore shard restore reflection workaround (#2559)

Turns out `dagstore` has bug in its restore shard code. For each shard
it attempts to create deep copy of registered type, but copies only
basic struct fields of the mount type. In out case it means, that it
copies a pointer. That causes all shards to point to the same mount
(same pointer).
Before `dagstore` is fixed to take into account possibility of
pointers/interface (and any other reference type) in mount type struct
fields, we will use direct copy of `mount.FileMount` instead of
`mount.Mount` interface.

(cherry picked from commit 003c2c4)

nodebuilder/store_test.go

@@ -4,9 +4,8 @@ import (
 	"context"
 	"strconv"
 	"testing"
+	"time"
 
-	"github.com/ipfs/go-datastore"
-	ds_sync "github.com/ipfs/go-datastore/sync"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -68,30 +67,13 @@ func BenchmarkStore(b *testing.B) {
 	ctx, cancel := context.WithCancel(context.Background())
 	b.Cleanup(cancel)
 
-	tmpDir := b.TempDir()
-	ds := ds_sync.MutexWrap(datastore.NewMapDatastore())
-	edsStore, err := eds.NewStore(tmpDir, ds)
-	require.NoError(b, err)
-	err = edsStore.Start(ctx)
-	require.NoError(b, err)
-
 	// BenchmarkStore/bench_read_128-10         	      14	  78970661 ns/op (~70ms)
 	b.Run("bench put 128", func(b *testing.B) {
-		b.ResetTimer()
 		dir := b.TempDir()
-
 		err := Init(*DefaultConfig(node.Full), dir, node.Full)
 		require.NoError(b, err)
 
-		store, err := OpenStore(dir, nil)
-		require.NoError(b, err)
-		ds, err := store.Datastore()
-		require.NoError(b, err)
-		edsStore, err := eds.NewStore(dir, ds)
-		require.NoError(b, err)
-		err = edsStore.Start(ctx)
-		require.NoError(b, err)
-
+		store := newStore(ctx, b, dir)
 		size := 128
 		b.Run("enabled eds proof caching", func(b *testing.B) {
 			b.StopTimer()
@@ -111,7 +93,7 @@ func BenchmarkStore(b *testing.B) {
 				ctx := ipld.CtxWithProofsAdder(ctx, adder)
 
 				b.StartTimer()
-				err = edsStore.Put(ctx, dah.Hash(), eds)
+				err = store.edsStore.Put(ctx, dah.Hash(), eds)
 				b.StopTimer()
 				require.NoError(b, err)
 			}
@@ -126,10 +108,76 @@ func BenchmarkStore(b *testing.B) {
 				require.NoError(b, err)
 
 				b.StartTimer()
-				err = edsStore.Put(ctx, dah.Hash(), eds)
+				err = store.edsStore.Put(ctx, dah.Hash(), eds)
 				b.StopTimer()
 				require.NoError(b, err)
 			}
 		})
 	})
 }
+
+func TestStoreRestart(t *testing.T) {
+	const (
+		blocks = 5
+		size   = 32
+	)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	t.Cleanup(cancel)
+
+	dir := t.TempDir()
+	err := Init(*DefaultConfig(node.Full), dir, node.Full)
+	require.NoError(t, err)
+
+	store := newStore(ctx, t, dir)
+
+	hashes := make([][]byte, blocks)
+	for i := range hashes {
+		edss := edstest.RandEDS(t, size)
+		require.NoError(t, err)
+		dah, err := da.NewDataAvailabilityHeader(edss)
+		require.NoError(t, err)
+		err = store.edsStore.Put(ctx, dah.Hash(), edss)
+		require.NoError(t, err)
+
+		// store hashes for read loop later
+		hashes[i] = dah.Hash()
+	}
+
+	// restart store
+	store.stop(ctx, t)
+	store = newStore(ctx, t, dir)
+
+	for _, h := range hashes {
+		edsReader, err := store.edsStore.GetCAR(ctx, h)
+		require.NoError(t, err)
+		odsReader, err := eds.ODSReader(edsReader)
+		require.NoError(t, err)
+		_, err = eds.ReadEDS(ctx, odsReader, h)
+		require.NoError(t, err)
+	}
+}
+
+type store struct {
+	s        Store
+	edsStore *eds.Store
+}
+
+func newStore(ctx context.Context, t require.TestingT, dir string) store {
+	s, err := OpenStore(dir, nil)
+	require.NoError(t, err)
+	ds, err := s.Datastore()
+	require.NoError(t, err)
+	edsStore, err := eds.NewStore(dir, ds)
+	require.NoError(t, err)
+	err = edsStore.Start(ctx)
+	require.NoError(t, err)
+	return store{
+		s:        s,
+		edsStore: edsStore,
+	}
+}
+
+func (s *store) stop(ctx context.Context, t *testing.T) {
+	require.NoError(t, s.edsStore.Stop(ctx))
+	require.NoError(t, s.s.Close())
+}

share/eds/store.go

@@ -75,7 +75,7 @@ func NewStore(basepath string, ds datastore.Batching) (*Store, error) {
 	}
 
 	r := mount.NewRegistry()
-	err = r.Register("fs", &inMemoryOnceMount{Mount: &mount.FileMount{}})
+	err = r.Register("fs", &inMemoryOnceMount{})
 	if err != nil {
 		return nil, fmt.Errorf("failed to register memory mount on the registry: %w", err)
 	}
@@ -212,8 +212,8 @@ func (s *Store) put(ctx context.Context, root share.DataHash, square *rsmt2d.Ext
 	// save encoded eds into buffer
 	mount := &inMemoryOnceMount{
 		// TODO: buffer could be pre-allocated with capacity calculated based on eds size.
-		buf:   bytes.NewBuffer(nil),
-		Mount: &mount.FileMount{Path: s.basepath + blocksPath + key},
+		buf:       bytes.NewBuffer(nil),
+		FileMount: mount.FileMount{Path: s.basepath + blocksPath + key},
 	}
 	err = WriteEDS(ctx, square, mount)
 	if err != nil {
@@ -565,7 +565,7 @@ type inMemoryOnceMount struct {
 	buf *bytes.Buffer
 
 	readOnce atomic.Bool
-	mount.Mount
+	mount.FileMount
 }
 
 func (m *inMemoryOnceMount) Fetch(ctx context.Context) (mount.Reader, error) {
@@ -575,7 +575,7 @@ func (m *inMemoryOnceMount) Fetch(ctx context.Context) (mount.Reader, error) {
 		m.buf = nil
 		return reader, nil
 	}
-	return m.Mount.Fetch(ctx)
+	return m.FileMount.Fetch(ctx)
 }
 
 func (m *inMemoryOnceMount) Write(b []byte) (int, error) {