+ maple_tree-remove-lockdep_map_p-typedef.patch added to mm-new branch

+ maple_tree-remove-lockdep_map_p-typedef.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: remove lockdep_map_p typedef
has been added to the -mm mm-new branch.  Its filename is
     maple_tree-remove-lockdep_map_p-typedef.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-remove-lockdep_map_p-typedef.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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fixup patches in mm-new.

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------------------------------------------------------
From: Alice Ryhl <aliceryhl@google.com>
Subject: maple_tree: remove lockdep_map_p typedef
Date: Tue, 02 Sep 2025 08:36:11 +0000

Having the ma_external_lock field exist when CONFIG_LOCKDEP=n isn't used
anywhere, so just get rid of it.  This also avoids generating a typedef
called lockdep_map_p that could overlap with typedefs in other header
files.

Link: https://lkml.kernel.org/r/20250902-maple-lockdep-p-v1-1-3ae5a398a379@google.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/maple_tree.h |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/include/linux/maple_tree.h~maple_tree-remove-lockdep_map_p-typedef
+++ a/include/linux/maple_tree.h
@@ -194,7 +194,6 @@ enum store_type {
 #define MAPLE_RESERVED_RANGE	4096
 
 #ifdef CONFIG_LOCKDEP
-typedef struct lockdep_map *lockdep_map_p;
 #define mt_lock_is_held(mt)                                             \
 	(!(mt)->ma_external_lock || lock_is_held((mt)->ma_external_lock))
 
@@ -207,7 +206,6 @@ typedef struct lockdep_map *lockdep_map_
 
 #define mt_on_stack(mt)			(mt).ma_external_lock = NULL
 #else
-typedef struct { /* nothing */ } lockdep_map_p;
 #define mt_lock_is_held(mt)		1
 #define mt_write_lock_is_held(mt)	1
 #define mt_set_external_lock(mt, lock)	do { } while (0)
@@ -230,8 +228,10 @@ typedef struct { /* nothing */ } lockdep
  */
 struct maple_tree {
 	union {
-		spinlock_t	ma_lock;
-		lockdep_map_p	ma_external_lock;
+		spinlock_t		ma_lock;
+#ifdef CONFIG_LOCKDEP
+		struct lockdep_map	*ma_external_lock;
+#endif
 	};
 	unsigned int	ma_flags;
 	void __rcu      *ma_root;
_

Patches currently in -mm which might be from aliceryhl@google.com are

rust-maple_tree-add-mapletree.patch
rust-maple_tree-add-lock-guard-for-maple-tree.patch
rust-maple_tree-add-mapletreealloc.patch
maple_tree-remove-lockdep_map_p-typedef.patch