From a6b6a938deced0d99475cc07620b3cc8005eeee8 Mon Sep 17 00:00:00 2001
From: Preston Van Loon <pvanloon@offchainlabs.com>
Date: Tue, 5 Dec 2023 13:57:08 -0600
Subject: [PATCH] blobstorage: Improve mkdirall error  (#13271)

---
 beacon-chain/db/filesystem/blob.go      |  2 +-
 beacon-chain/db/filesystem/blob_test.go | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/beacon-chain/db/filesystem/blob.go b/beacon-chain/db/filesystem/blob.go
index 1c178e188..8cbe6e877 100644
--- a/beacon-chain/db/filesystem/blob.go
+++ b/beacon-chain/db/filesystem/blob.go
@@ -36,7 +36,7 @@ const (
 func NewBlobStorage(base string) (*BlobStorage, error) {
 	base = path.Clean(base)
 	if err := file.MkdirAll(base); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to create blob storage at %s: %w", base, err)
 	}
 	fs := afero.NewBasePathFs(afero.NewOsFs(), base)
 	return &BlobStorage{fs: fs}, nil
diff --git a/beacon-chain/db/filesystem/blob_test.go b/beacon-chain/db/filesystem/blob_test.go
index ae895ed5d..8ca55f60f 100644
--- a/beacon-chain/db/filesystem/blob_test.go
+++ b/beacon-chain/db/filesystem/blob_test.go
@@ -2,6 +2,8 @@ package filesystem
 
 import (
 	"bytes"
+	"os"
+	"path"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -129,3 +131,14 @@ func TestBlobStorageDelete(t *testing.T) {
 	// Deleting a non-existent root does not return an error.
 	require.NoError(t, bs.Delete(bytesutil.ToBytes32([]byte{0x1})))
 }
+
+func TestNewBlobStorage(t *testing.T) {
+	_, err := NewBlobStorage(path.Join(t.TempDir(), "good"))
+	require.NoError(t, err)
+
+	// If directory already exists with improper permissions, expect a wrapped err message.
+	fp := path.Join(t.TempDir(), "bad")
+	require.NoError(t, os.Mkdir(fp, 0777))
+	_, err = NewBlobStorage(fp)
+	require.ErrorContains(t, "failed to create blob storage", err)
+}