From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 8 Sep 2020 17:59:56 +0000 (-0400)
Subject: maple_tree: Change mas_get_slot to only rcu_dereference when necessary
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=10f354cb437a8280cf697aa948d62269d7b88c94;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Change mas_get_slot to only rcu_dereference when necessary

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 578772401d338..5066e54604710 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -588,8 +588,11 @@ static inline struct maple_enode *mas_get_slot(struct ma_state *mas,
 {
 	void **slots = ma_get_slots(mte_to_node(mas->node),
 				    mte_node_type(mas->node));
-	return rcu_dereference_check(slots[offset],
-				lockdep_is_held(mas->tree->ma_lock));
+	if (mt_in_rcu(mas->tree))
+		return rcu_dereference_check(slots[offset],
+					lockdep_is_held(mas->tree->ma_lock));
+	else
+		return slots[offset];
 }
 
 /*