From 2f88dafa56ac9cfb36cb913364d85cb8ca90d6d6 Mon Sep 17 00:00:00 2001
From: Andreas Sommer <andreas.sommer87@googlemail.com>
Date: Mon, 20 Feb 2023 15:41:10 +0100
Subject: [PATCH] Only fail after chmod error if permissions differ (e.g. on
 config file) (#8771)

---
 lib/osutil/atomic.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/osutil/atomic.go b/lib/osutil/atomic.go
index 0e8483617..a0422b8f4 100644
--- a/lib/osutil/atomic.go
+++ b/lib/osutil/atomic.go
@@ -109,9 +109,15 @@ func (w *AtomicWriter) Close() error {
 		return err
 	}
 	if infoErr == nil {
+		// Restore chmod setting for final file to what it was
 		if err := w.fs.Chmod(w.path, info.Mode()); err != nil {
-			w.err = err
-			return err
+			// Only fail if permissions differ, since some filesystems are expected to not allow chmod (e.g. error
+			// `operation not permitted`).
+			infoAfterRename, infoAfterRenameErr := w.fs.Lstat(w.path)
+			if infoAfterRenameErr != nil || infoAfterRename.Mode() != info.Mode() {
+				w.err = err
+				return err
+			}
 		}
 	}