From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 11 Apr 2023 15:10:52 +0000 (-0400)
Subject: maple_tree: remove extra smp_wmb() from mas_dead_leaves()
X-Git-Tag: v6.2.11~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=425e737db89bd9774ae4fdd51f93fc5f8bb63c9e;p=thirdparty%2Fkernel%2Fstable.git

maple_tree: remove extra smp_wmb() from mas_dead_leaves()

commit 8372f4d83f96f35915106093cde4565836587123 upstream.

The call to mte_set_dead_node() before the smp_wmb() already calls
smp_wmb() so this is not needed.  This is an optimization for the RCU mode
of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-5-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Cc: stable@vger.kernel.org
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f7513c549a94d..aeb218f2ef285 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5500,7 +5500,6 @@ unsigned char mas_dead_leaves(struct ma_state *mas, void __rcu **slots,
 			break;
 
 		mte_set_node_dead(entry);
-		smp_wmb(); /* Needed for RCU */
 		node->type = type;
 		rcu_assign_pointer(slots[offset], node);
 	}