From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon, 2 Mar 2020 21:09:00 +0000 (-0500)
Subject: maple_tree: no need to rcu_dereference in mtree_empty()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=da9683f694c119eef6772f0ab376bfbb601e6ea3;p=users%2Fjedix%2Flinux-maple.git

maple_tree: no need to rcu_dereference in mtree_empty()

Since we're only comparing the value of the pointer to NULL, we
don't need to use rcu_dereference().  This is explicitly documented
in Documentation/RCU/rcu_dereference.rst.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---

diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index a5d75366b24f3..9c17fdb729541 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -226,7 +226,7 @@ int mtree_store_range(struct maple_tree *mt, unsigned long first,
  */
 static inline bool mtree_empty(const struct maple_tree *mt)
 {
-	return rcu_dereference(mt->ma_root) == NULL;
+	return mt->ma_root == NULL;
 }
 
 /* Advanced API */