From d5e17554f4919a68f2f4fd17820d794859feaf4c Mon Sep 17 00:00:00 2001
From: Ray Tien <ray.tien0907@gmail.com>
Date: Mon, 22 Dec 2025 21:36:55 +0800
Subject: [PATCH] fix(filesystem): add comma separator in mountOptionsString

  mountOptionsString was concatenating options without commas, breaking
  readonly dete

  Signed-off-by: Ray Tien <ray.tien0907@gmail.com>
---
 collector/filesystem_linux.go | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/collector/filesystem_linux.go b/collector/filesystem_linux.go
index 3739f0fe..0a3055f3 100644
--- a/collector/filesystem_linux.go
+++ b/collector/filesystem_linux.go
@@ -16,7 +16,6 @@
 package collector
 
 import (
-	"bytes"
 	"errors"
 	"fmt"
 	"log/slog"
@@ -237,13 +236,13 @@ func isFilesystemReadOnly(labels filesystemLabels) bool {
 }
 
 func mountOptionsString(m map[string]string) string {
-	b := new(bytes.Buffer)
+	var parts []string
 	for key, value := range m {
 		if value == "" {
-			fmt.Fprintf(b, "%s", key)
+			parts = append(parts, key)
 		} else {
-			fmt.Fprintf(b, "%s=%s", key, value)
+			parts = append(parts, key+"="+value)
 		}
 	}
-	return b.String()
+	return strings.Join(parts, ",")
 }