diff --git a/Makefile b/Makefile
index eeb254ea..581558fe 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 GO ?= go
 GOLANGCI_LINT ?= $$($(GO) env GOPATH)/bin/golangci-lint
-GOLANGCI_LINT_VERSION ?= v1.57.1
+GOLANGCI_LINT_VERSION ?= v1.61.0
 GOGOPROTOBUF ?= protoc-gen-gogofaster
 GOGOPROTOBUF_VERSION ?= v1.3.1
 
diff --git a/cmd/dfs-cli/cmd/fdfs-api.go b/cmd/dfs-cli/cmd/fdfs-api.go
index 8f48d963..5467c882 100644
--- a/cmd/dfs-cli/cmd/fdfs-api.go
+++ b/cmd/dfs-cli/cmd/fdfs-api.go
@@ -107,7 +107,7 @@ func (s *fdfsClient) getAccessToken() string {
 
 func (s *fdfsClient) postReq(method, urlPath string, jsonBytes []byte) ([]byte, error) {
 	// prepare the  request
-	fullUrl := fmt.Sprintf(s.url + urlPath)
+	fullUrl := fmt.Sprintf("%s%s", s.url, urlPath)
 	var req *http.Request
 	var err error
 	if jsonBytes != nil {
@@ -178,7 +178,7 @@ func (s *fdfsClient) postReq(method, urlPath string, jsonBytes []byte) ([]byte,
 }
 
 func (s *fdfsClient) getReq(urlPath, argsString string) ([]byte, error) {
-	fullUrl := fmt.Sprintf(s.url + urlPath)
+	fullUrl := fmt.Sprintf("%s%s", s.url, urlPath)
 	var req *http.Request
 	var err error
 	if argsString != "" {
@@ -270,7 +270,7 @@ func (s *fdfsClient) uploadMultipartFile(urlPath, fileName string, fileSize int6
 		return nil, err
 	}
 
-	fullUrl := fmt.Sprintf(s.url + urlPath)
+	fullUrl := fmt.Sprintf("%s%s", s.url, urlPath)
 	req, err := http.NewRequest(http.MethodPost, fullUrl, body)
 	if err != nil {
 		return nil, err
@@ -312,7 +312,7 @@ func (s *fdfsClient) uploadMultipartFile(urlPath, fileName string, fileSize int6
 
 func (s *fdfsClient) downloadMultipartFile(method, urlPath string, arguments map[string]string, out *os.File) (int64, error) {
 	// prepare the  request
-	fullUrl := fmt.Sprintf(s.url + urlPath)
+	fullUrl := fmt.Sprintf("%s%s", s.url, urlPath)
 	var req *http.Request
 	var err error
 
diff --git a/pkg/blockstore/bee/client.go b/pkg/blockstore/bee/client.go
index 95ef7d71..42cfd7da 100644
--- a/pkg/blockstore/bee/client.go
+++ b/pkg/blockstore/bee/client.go
@@ -180,7 +180,7 @@ func (s *Client) Do(req *http.Request) (*http.Response, error) {
 func (s *Client) UploadSOC(owner, id, signature string, data []byte) (address []byte, err error) {
 	to := time.Now()
 	socResStr := socResource(owner, id, signature)
-	fullUrl := fmt.Sprintf(s.url + socResStr)
+	fullUrl := fmt.Sprintf("%s%s", s.url, socResStr)
 
 	req, err := http.NewRequest(http.MethodPost, fullUrl, bytes.NewBuffer(data))
 	if err != nil {
@@ -238,7 +238,7 @@ func (s *Client) UploadSOC(owner, id, signature string, data []byte) (address []
 // UploadChunk uploads a chunk to Swarm network.
 func (s *Client) UploadChunk(ch swarm.Chunk) (address []byte, err error) {
 	to := time.Now()
-	fullUrl := fmt.Sprintf(s.url + chunkUploadDownloadUrl)
+	fullUrl := fmt.Sprintf("%s%s", s.url, chunkUploadDownloadUrl)
 	req, err := http.NewRequest(http.MethodPost, fullUrl, bytes.NewBuffer(ch.Data()))
 	if err != nil {
 		return nil, err
@@ -298,7 +298,7 @@ func (s *Client) DownloadChunk(ctx context.Context, address []byte) (data []byte
 	addrString := swarm.NewAddress(address).String()
 
 	path := chunkUploadDownloadUrl + "/" + addrString
-	fullUrl := fmt.Sprintf(s.url + path)
+	fullUrl := fmt.Sprintf("%s%s", s.url, path)
 	req, err := http.NewRequest(http.MethodGet, fullUrl, bytes.NewBuffer(data))
 	if err != nil {
 		return nil, err
diff --git a/pkg/dir/rmdir.go b/pkg/dir/rmdir.go
index 1918a5f7..6ca07012 100644
--- a/pkg/dir/rmdir.go
+++ b/pkg/dir/rmdir.go
@@ -52,7 +52,7 @@ func (d *Directory) RmDir(directoryNameWithPath, podPassword string) error {
 		return ErrDirectoryNotPresent
 	}
 
-	if dirInode.FileOrDirNames != nil && len(dirInode.FileOrDirNames) > 0 {
+	if len(dirInode.FileOrDirNames) > 0 {
 		for _, fileOrDirName := range dirInode.FileOrDirNames {
 			if strings.HasPrefix(fileOrDirName, "_F_") {
 				fileName := strings.TrimPrefix(fileOrDirName, "_F_")
@@ -93,7 +93,7 @@ func (d *Directory) RmRootDir(podPassword string) error {
 	}
 	// recursive delete
 	dirInode := d.GetDirFromDirectoryMap(totalPath)
-	if dirInode.FileOrDirNames != nil && len(dirInode.FileOrDirNames) > 0 {
+	if len(dirInode.FileOrDirNames) > 0 {
 		for _, fileOrDirName := range dirInode.FileOrDirNames {
 			if strings.HasPrefix(fileOrDirName, "_F_") {
 				fileName := strings.TrimPrefix(fileOrDirName, "_F_")