From 134d153c9346fc1b2842cacec8720da3a9667a11 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Date: Fri, 14 Jul 2023 15:55:49 -0400
Subject: [PATCH] maple_tree: relax lockdep checks for on-stack trees
To support early release of the maple tree locks, do not lockdep check the
lock if it is set to NULL. This is intended for the special case on-stack
use of tracking entries and not for general use.
Link: https://lkml.kernel.org/r/20230714195551.894800-3-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oliver Sang <oliver.sang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/maple_tree.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index 7769270b85e89..6618c15128867 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -182,7 +182,9 @@ enum maple_type {
#ifdef CONFIG_LOCKDEP
typedef struct lockdep_map *lockdep_map_p;
-#define mt_lock_is_held(mt) lock_is_held(mt->ma_external_lock)
+#define mt_lock_is_held(mt) \
+ (!(mt)->ma_external_lock || lock_is_held((mt)->ma_external_lock))
+
#define mt_set_external_lock(mt, lock) \
(mt)->ma_external_lock = &(lock)->dep_map
#else
--
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