server/storage: check whether path exists before trying to create directory

server/src/storage/local.rs

@@ -101,13 +101,20 @@ async fn upgrade_0_to_1(storage_path: &Path) -> ServerResult<()> {
 
 impl LocalBackend {
     pub async fn new(config: LocalStorageConfig) -> ServerResult<Self> {
-        fs::create_dir_all(&config.path).await.map_err(|e| {
+        if !fs::try_exists(&config.path).await.map_err(|e| {
             ErrorKind::StorageError(anyhow::anyhow!(
-                "Failed to create storage directory {}: {}",
-                config.path.display(),
-                e
+                "Failed to check whether storage directory {} exists: {e}",
+                config.path.display()
             ))
-        })?;
+        })? {
+            fs::create_dir_all(&config.path).await.map_err(|e| {
+                ErrorKind::StorageError(anyhow::anyhow!(
+                    "Failed to create storage directory {}: {}",
+                    config.path.display(),
+                    e
+                ))
+            })?;
+        };
 
         let version = read_version(&config.path).await?;
         if version == 0 {