From b3464e8140102ad585b8fa65c331d2bf3fbfe83a Mon Sep 17 00:00:00 2001
From: Alex Vanin <alexey@nspcc.ru>
Date: Wed, 22 Sep 2021 17:04:45 +0300
Subject: [PATCH] [#839] service/object: Do not use request forwarding when
 assembling object

Forwarding mechanism resends original request. During split object chain traversal,
storage node performs multiple `object.Head` requests on each child. If request
forwarding happens, then `object.Head` returns object ID of the original request.
This produces infinite assembly loop.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>
---
 pkg/services/object/get/assemble.go | 6 +++++-
 pkg/services/object/get/exec.go     | 6 ------
 pkg/services/object/get/util.go     | 2 +-
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/pkg/services/object/get/assemble.go b/pkg/services/object/get/assemble.go
index bcbd581c..7f8aade2 100644
--- a/pkg/services/object/get/assemble.go
+++ b/pkg/services/object/get/assemble.go
@@ -12,7 +12,11 @@ func (exec *execCtx) assemble() {
 		return
 	}
 
-	exec.assembling = true
+	// do not use forwarding during assembly stage
+	// assembly flag is not inherited in produced
+	// `execCtx`, however `commonPrm` does, so it
+	// makes sense to nil it there
+	exec.prm.SetRequestForwarder(nil)
 
 	exec.log.Debug("trying to assemble the object...")
 
diff --git a/pkg/services/object/get/exec.go b/pkg/services/object/get/exec.go
index d92a29d2..58ac46e7 100644
--- a/pkg/services/object/get/exec.go
+++ b/pkg/services/object/get/exec.go
@@ -41,12 +41,6 @@ type execCtx struct {
 	head bool
 
 	curProcEpoch uint64
-
-	// true when the processing of the initial request
-	// is turned to assembling stage. When false,
-	// initial request can be forwarded during network
-	// communication.
-	assembling bool
 }
 
 type execOption func(*execCtx)
diff --git a/pkg/services/object/get/util.go b/pkg/services/object/get/util.go
index 90ea40a5..7a1ff0cb 100644
--- a/pkg/services/object/get/util.go
+++ b/pkg/services/object/get/util.go
@@ -82,7 +82,7 @@ func (c *clientCacheWrapper) get(addr network.AddressGroup) (getClient, error) {
 }
 
 func (c *clientWrapper) getObject(exec *execCtx, addr network.AddressGroup) (*objectSDK.Object, error) {
-	if !exec.assembling && exec.prm.forwarder != nil {
+	if exec.prm.forwarder != nil {
 		return exec.prm.forwarder(addr, c.client)
 	}