[#1086] engine: Do not use metabase if shard looks bad

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/engine/head.go

@@ -85,6 +85,7 @@ func (e *StorageEngine) head(ctx context.Context, prm HeadPrm) (HeadRes, error)
 	shPrm.SetRaw(prm.raw)
 
 	e.iterateOverSortedShards(prm.addr, func(_ int, sh hashedShard) (stop bool) {
+		shPrm.ShardLooksBad = sh.errorCount.Load() >= e.errorsThreshold
 		res, err := sh.Head(ctx, shPrm)
 		if err != nil {
 			switch {

pkg/local_object_storage/shard/head.go

@@ -13,8 +13,9 @@ import (
 
 // HeadPrm groups the parameters of Head operation.
 type HeadPrm struct {
-	addr oid.Address
-	raw  bool
+	addr          oid.Address
+	raw           bool
+	ShardLooksBad bool
 }
 
 // HeadRes groups the resulting values of Head operation.
@@ -59,7 +60,8 @@ func (s *Shard) Head(ctx context.Context, prm HeadPrm) (HeadRes, error) {
 
 	var obj *objectSDK.Object
 	var err error
-	if s.GetMode().NoMetabase() {
+	mode := s.GetMode()
+	if mode.NoMetabase() || (mode.ReadOnly() && prm.ShardLooksBad) {
 		var getPrm GetPrm
 		getPrm.SetAddress(prm.addr)
 		getPrm.SetIgnoreMeta(true)