From 38d6c60e146a67d7a2b0c71a7bb8640afc454472 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Fri, 28 Aug 2020 15:32:05 -0400
Subject: [PATCH] sched/mm and kernel/fork: Add maple tree rcu enable/disable

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 include/linux/sched/mm.h | 3 +++
 kernel/fork.c            | 1 +
 2 files changed, 4 insertions(+)

diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index d5ece7a9a403..919e2e44b764 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -8,6 +8,7 @@
 #include <linux/mm_types.h>
 #include <linux/gfp.h>
 #include <linux/sync_core.h>
+#include <linux/maple_tree.h>
 
 /*
  * Routines for handling mm_structs
@@ -67,11 +68,13 @@ static inline void mmdrop(struct mm_struct *mm)
  */
 static inline void mmget(struct mm_struct *mm)
 {
+	mt_set_in_rcu(&mm->mm_mt);
 	atomic_inc(&mm->mm_users);
 }
 
 static inline bool mmget_not_zero(struct mm_struct *mm)
 {
+	mt_set_in_rcu(&mm->mm_mt);
 	return atomic_inc_not_zero(&mm->mm_users);
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 7de6437caa65..5ea4b5690508 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1095,6 +1095,7 @@ static inline void __mmput(struct mm_struct *mm)
 	}
 	if (mm->binfmt)
 		module_put(mm->binfmt->module);
+	mt_clear_in_rcu(&mm->mm_mt);
 	mmdrop(mm);
 }
 
-- 
2.50.1