[#874] engine: Revert Check object existance concurrently

This reverts commit f526f49995.

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

pkg/local_object_storage/blobstor/blobovniczatree/get.go

@@ -94,11 +94,6 @@ func (b *Blobovniczas) Get(ctx context.Context, prm common.GetPrm) (res common.G
 //
 // returns error if object could not be read from any blobovnicza of the same level.
 func (b *Blobovniczas) getObjectFromLevel(ctx context.Context, prm blobovnicza.GetPrm, blzPath string) (common.GetRes, error) {
-	select {
-	case <-ctx.Done():
-		return common.GetRes{}, ctx.Err()
-	default:
-	}
 	// open blobovnicza (cached inside)
 	shBlz := b.getBlobovnicza(blzPath)
 	blz, err := shBlz.Open()

pkg/local_object_storage/blobstor/blobovniczatree/iterate.go

@@ -230,12 +230,6 @@ func (b *Blobovniczas) iterateSortedDBPaths(ctx context.Context, addr oid.Addres
 }
 
 func (b *Blobovniczas) iterateSordedDBPathsInternal(ctx context.Context, path string, addr oid.Address, f func(string) (bool, error)) (bool, error) {
-	select {
-	case <-ctx.Done():
-		return false, ctx.Err()
-	default:
-	}
-
 	sysPath := filepath.Join(b.rootPath, path)
 	entries, err := os.ReadDir(sysPath)
 	if os.IsNotExist(err) && b.readOnly && path == "" { // non initialized tree in read only mode
@@ -258,12 +252,6 @@ func (b *Blobovniczas) iterateSordedDBPathsInternal(ctx context.Context, path st
 
 	if len(dbIdxs) > 0 {
 		for _, dbIdx := range dbIdxs {
-			select {
-			case <-ctx.Done():
-				return false, ctx.Err()
-			default:
-			}
-
 			dbPath := filepath.Join(path, u64ToHexStringExt(dbIdx))
 			stop, err := f(dbPath)
 			if err != nil {
@@ -278,12 +266,6 @@ func (b *Blobovniczas) iterateSordedDBPathsInternal(ctx context.Context, path st
 	if len(dirIdxs) > 0 {
 		hrw.SortSliceByValue(dirIdxs, addressHash(&addr, path))
 		for _, dirIdx := range dirIdxs {
-			select {
-			case <-ctx.Done():
-				return false, ctx.Err()
-			default:
-			}
-
 			dirPath := filepath.Join(path, u64ToHexString(dirIdx))
 			stop, err := b.iterateSordedDBPathsInternal(ctx, dirPath, addr, f)
 			if err != nil {

pkg/local_object_storage/blobstor/exists.go

@@ -3,7 +3,6 @@ package blobstor
 import (
 	"context"
 	"encoding/hex"
-	"errors"
 	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
@@ -58,30 +57,27 @@ func (b *BlobStor) Exists(ctx context.Context, prm common.ExistsPrm) (common.Exi
 	// error     | found       | log the error, return true, nil
 	// error     | not found   | return the error
 	// error     | error       | log the first error, return the second
-	var storageErrors []error
+	var errors []error
 	for i := range b.storage {
 		res, err := b.storage[i].Storage.Exists(ctx, prm)
 		if err == nil && res.Exists {
 			exists = true
 			return res, nil
 		} else if err != nil {
-			if errors.Is(err, context.Canceled) {
-				return common.ExistsRes{}, err
-			}
-			storageErrors = append(storageErrors, err)
+			errors = append(errors, err)
 		}
 	}
 
-	if len(storageErrors) == 0 {
+	if len(errors) == 0 {
 		return common.ExistsRes{}, nil
 	}
 
-	for _, err := range storageErrors[:len(storageErrors)-1] {
+	for _, err := range errors[:len(errors)-1] {
 		b.log.Warn(logs.BlobstorErrorOccurredDuringObjectExistenceChecking,
 			zap.Stringer("address", prm.Address),
 			zap.String("error", err.Error()),
 			zap.String("trace_id", tracingPkg.GetTraceID(ctx)))
 	}
 
-	return common.ExistsRes{}, storageErrors[len(storageErrors)-1]
+	return common.ExistsRes{}, errors[len(errors)-1]
 }

pkg/local_object_storage/blobstor/fstree/fstree.go

@@ -285,12 +285,6 @@ func (t *FSTree) Exists(ctx context.Context, prm common.ExistsPrm) (common.Exist
 		))
 	defer span.End()
 
-	select {
-	case <-ctx.Done():
-		return common.ExistsRes{}, ctx.Err()
-	default:
-	}
-
 	p := t.treePath(prm.Address)
 
 	_, err := os.Stat(p)