From 6fb362210cdd54703ce89078fa87457c4f133996 Mon Sep 17 00:00:00 2001
From: xinque <231098078@smail.nju.edu.cn>
Date: Mon, 29 Jun 2026 22:31:37 +0800
Subject: [PATCH 1/2] Add comments to checkIfRemountRequired in ufs.go

Signed-off-by: xinque <231098078@smail.nju.edu.cn>
---
 pkg/ddc/alluxio/ufs.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkg/ddc/alluxio/ufs.go b/pkg/ddc/alluxio/ufs.go
index 9d466880443..c494647f79b 100644
--- a/pkg/ddc/alluxio/ufs.go
+++ b/pkg/ddc/alluxio/ufs.go
@@ -163,6 +163,10 @@ func (e *AlluxioEngine) UpdateOnUFSChange(ufsToUpdate *utils.UFSToUpdate) (updat
 	return
 }
 
+// checkIfRemountRequired checks whether a remount operation is needed for the given UFS.
+// It compares the runtime's MountTime with the Alluxio master container's start time.
+// If the master container started after the last mount, it means the mount data was lost
+// due to container restart, so it finds unmounted UFS paths and schedules a remount.
 func (e *AlluxioEngine) checkIfRemountRequired(ufsToUpdate *utils.UFSToUpdate) {
 	runtime, err := e.getRuntime()
 	if err != nil {

From d0bb7bf7a0ca88572bf177aa9d8ddf993334e307 Mon Sep 17 00:00:00 2001
From: xinque <231098078@smail.nju.edu.cn>
Date: Tue, 30 Jun 2026 10:50:10 +0800
Subject: [PATCH 2/2] Update comments to checkIfRemountRequired per review
 feedback

Signed-off-by: xinque <231098078@smail.nju.edu.cn>
---
 pkg/ddc/alluxio/ufs.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/pkg/ddc/alluxio/ufs.go b/pkg/ddc/alluxio/ufs.go
index c494647f79b..dd66355d319 100644
--- a/pkg/ddc/alluxio/ufs.go
+++ b/pkg/ddc/alluxio/ufs.go
@@ -165,8 +165,14 @@ func (e *AlluxioEngine) UpdateOnUFSChange(ufsToUpdate *utils.UFSToUpdate) (updat
 
 // checkIfRemountRequired checks whether a remount operation is needed for the given UFS.
 // It compares the runtime's MountTime with the Alluxio master container's start time.
-// If the master container started after the last mount, it means the mount data was lost
-// due to container restart, so it finds unmounted UFS paths and schedules a remount.
+// If the master container started after the last mount, the in-memory mount state may not
+// have survived the restart, so it finds unmounted UFS paths and adds them to ufsToUpdate
+// for remount scheduling. If no paths need remounting, it refreshes the runtime's MountTime
+// to prevent the check from re-firing on every reconcile.
+//
+// Parameters:
+//   - ufsToUpdate (*utils.UFSToUpdate): An in/out parameter that may be mutated via
+//     AddMountPaths to carry unmounted paths back to the caller for remount scheduling.
 func (e *AlluxioEngine) checkIfRemountRequired(ufsToUpdate *utils.UFSToUpdate) {
 	runtime, err := e.getRuntime()
 	if err != nil {