[#1176] metabase: Ignore locked objects in IterateExpired

Make `DB.IterateExpired` to not pass locked objects to the handler. The
method is used by GC, therefore it will not consider them as candidates
for deletion.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/local_object_storage/metabase/iterators.go

@@ -38,7 +38,8 @@ type ExpiredObjectHandler func(*ExpiredObject) error
 var ErrInterruptIterator = errors.New("iterator is interrupted")
 
 // IterateExpired iterates over all objects in DB which are out of date
-// relative to epoch.
+// relative to epoch. Locked objects are not included (do not confuse
+// with objects of type LOCK).
 //
 // If h returns ErrInterruptIterator, nil returns immediately.
 // Returns other errors of h directly.
@@ -83,6 +84,14 @@ func (db *DB) iterateExpired(tx *bbolt.Tx, epoch uint64, h ExpiredObjectHandler)
 					return fmt.Errorf("could not parse container ID of expired bucket: %w", err)
 				}
 
+				// Ignore locked objects.
+				//
+				// To slightly optimize performance we can check only REGULAR objects
+				// (only they can be locked), but it's more reliable.
+				if objectLocked(tx, *cnrID, *id) {
+					return nil
+				}
+
 				addr := addressSDK.NewAddress()
 				addr.SetContainerID(cnrID)
 				addr.SetObjectID(id)

pkg/local_object_storage/metabase/iterators_test.go

@@ -9,6 +9,8 @@ import (
 	meta "github.com/nspcc-dev/neofs-node/pkg/local_object_storage/metabase"
 	"github.com/nspcc-dev/neofs-sdk-go/object"
 	addressSDK "github.com/nspcc-dev/neofs-sdk-go/object/address"
+	oid "github.com/nspcc-dev/neofs-sdk-go/object/id"
+	oidtest "github.com/nspcc-dev/neofs-sdk-go/object/id/test"
 	"github.com/stretchr/testify/require"
 )
 
@@ -30,11 +32,17 @@ func TestDB_IterateExpired(t *testing.T) {
 		mExpired[typ] = putWithExpiration(t, db, typ, epoch-1)
 	}
 
+	expiredLocked := putWithExpiration(t, db, object.TypeRegular, epoch-1)
+
+	require.NoError(t, db.Lock(*expiredLocked.ContainerID(), *oidtest.ID(), []oid.ID{*expiredLocked.ObjectID()}))
+
 	err := db.IterateExpired(epoch, func(exp *meta.ExpiredObject) error {
 		if addr, ok := mAlive[exp.Type()]; ok {
 			require.NotEqual(t, addr, exp.Address())
 		}
 
+		require.NotEqual(t, expiredLocked, exp.Address())
+
 		addr, ok := mExpired[exp.Type()]
 		require.True(t, ok)
 		require.Equal(t, addr, exp.Address())

pkg/local_object_storage/metabase/lock.go

@@ -97,3 +97,16 @@ func (db *DB) Lock(cnr cid.ID, locker oid.ID, locked []oid.ID) error {
 		return nil
 	})
 }
+
+// checks if specified object is locked in the specified container.
+func objectLocked(tx *bbolt.Tx, idCnr cid.ID, idObj oid.ID) bool {
+	bucketLocked := tx.Bucket(bucketNameLocked)
+	if bucketLocked != nil {
+		bucketLockedContainer := bucketLocked.Bucket([]byte(idCnr.String()))
+		if bucketLockedContainer != nil {
+			return bucketLockedContainer.Get(objectKey(&idObj)) != nil
+		}
+	}
+
+	return false
+}