The patch titled
Subject: maple_tree: introduce {mtree,mas}_lock_nested()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-introduce-mtreemas_lock_nested.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-introduce-mtreemas_lock_nested.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Subject: maple_tree: introduce {mtree,mas}_lock_nested()
Date: Fri, 27 Oct 2023 11:38:37 +0800
In some cases, nested locks may be needed, so {mtree,mas}_lock_nested is
introduced. For example, when duplicating maple tree, we need to hold the
locks of two trees, in which case nested locks are needed.
At the same time, add the definition of spin_lock_nested() in tools for
testing.
Link: https://lkml.kernel.org/r/20231027033845.90608-3-zhangpeng.00@xxxxxxxxxxxxx
Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Mateusz Guzik <mjguzik@xxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Mike Christie <michael.christie@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/maple_tree.h | 4 ++++
tools/include/linux/spinlock.h | 1 +
2 files changed, 5 insertions(+)
--- a/include/linux/maple_tree.h~maple_tree-introduce-mtreemas_lock_nested
+++ a/include/linux/maple_tree.h
@@ -256,6 +256,8 @@ struct maple_tree {
struct maple_tree name = MTREE_INIT(name, 0)
#define mtree_lock(mt) spin_lock((&(mt)->ma_lock))
+#define mtree_lock_nested(mas, subclass) \
+ spin_lock_nested((&(mt)->ma_lock), subclass)
#define mtree_unlock(mt) spin_unlock((&(mt)->ma_lock))
/*
@@ -406,6 +408,8 @@ struct ma_wr_state {
};
#define mas_lock(mas) spin_lock(&((mas)->tree->ma_lock))
+#define mas_lock_nested(mas, subclass) \
+ spin_lock_nested(&((mas)->tree->ma_lock), subclass)
#define mas_unlock(mas) spin_unlock(&((mas)->tree->ma_lock))
--- a/tools/include/linux/spinlock.h~maple_tree-introduce-mtreemas_lock_nested
+++ a/tools/include/linux/spinlock.h
@@ -11,6 +11,7 @@
#define spin_lock_init(x) pthread_mutex_init(x, NULL)
#define spin_lock(x) pthread_mutex_lock(x)
+#define spin_lock_nested(x, subclass) pthread_mutex_lock(x)
#define spin_unlock(x) pthread_mutex_unlock(x)
#define spin_lock_bh(x) pthread_mutex_lock(x)
#define spin_unlock_bh(x) pthread_mutex_unlock(x)
_
Patches currently in -mm which might be from zhangpeng.00@xxxxxxxxxxxxx are
maple_tree-add-mt_free_one-and-mt_attr-helpers.patch
maple_tree-introduce-mtreemas_lock_nested.patch
maple_tree-introduce-interfaces-__mt_dup-and-mtree_dup.patch
radix-tree-test-suite-align-kmem_cache_alloc_bulk-with-kernel-behavior.patch
maple_tree-add-test-for-mtree_dup.patch
maple_tree-update-the-documentation-of-maple-tree.patch
maple_tree-skip-other-tests-when-bench-is-enabled.patch
maple_tree-update-check_forking-and-bench_forking.patch
maple_tree-preserve-the-tree-attributes-when-destroying-maple-tree.patch
fork-use-__mt_dup-to-duplicate-maple-tree-in-dup_mmap.patch
