diff --git a/kmod/src/super.c b/kmod/src/super.c
index eccc6023..a54e8cf9 100644
--- a/kmod/src/super.c
+++ b/kmod/src/super.c
@@ -661,7 +661,12 @@ static struct dentry *scoutfs_mount(struct file_system_type *fs_type, int flags,
  */
 static void scoutfs_kill_sb(struct super_block *sb)
 {
-	trace_scoutfs_kill_sb(sb);
+	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
+
+	if (sbi) {
+		sbi->unmounting = true;
+		smp_wmb();
+	}
 
 	if (SCOUTFS_HAS_SBI(sb))
 		scoutfs_lock_unmount_begin(sb);
diff --git a/kmod/src/super.h b/kmod/src/super.h
index e7733856..92106b63 100644
--- a/kmod/src/super.h
+++ b/kmod/src/super.h
@@ -89,6 +89,7 @@ struct scoutfs_sb_info {
 	struct dentry *debug_root;
 
 	bool forced_unmount;
+	bool unmounting;
 
 	unsigned long corruption_messages_once[SC_NR_LONGS];
 };
@@ -117,6 +118,19 @@ static inline bool scoutfs_forcing_unmount(struct super_block *sb)
 	return sbi->forced_unmount;
 }
 
+/*
+ * True if we're shutting down the system and can be used as a coarse
+ * indicator that we can avoid doing some work that no longer makes
+ * sense.
+ */
+static inline bool scoutfs_unmounting(struct super_block *sb)
+{
+	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
+
+	smp_rmb();
+	return !sbi || sbi->unmounting;
+}
+
 /*
  * A small string embedded in messages that's used to identify a
  * specific mount.  It's the three most significant bytes of the fsid