diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index f91dbc7fe091..a452dd8a1e5c 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -329,6 +329,9 @@ int mtree_store(struct maple_tree *mt, unsigned long index,
 		void *entry, gfp_t gfp);
 void *mtree_erase(struct maple_tree *mt, unsigned long index);
 
+int mtree_dup(struct maple_tree *mt, struct maple_tree *new, gfp_t gfp);
+int __mt_dup(struct maple_tree *mt, struct maple_tree *new, gfp_t gfp);
+
 void mtree_destroy(struct maple_tree *mt);
 void __mt_destroy(struct maple_tree *mt);
 
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index ca7039633844..6704b5c507b2 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4,6 +4,10 @@
  * Copyright (c) 2018-2022 Oracle Corporation
  * Authors: Liam R. Howlett <Liam.Howlett@oracle.com>
  *	    Matthew Wilcox <willy@infradead.org>
+ *
+ * Implementation of algorithm for duplicating Maple Tree
+ * Copyright (c) 2023 ByteDance
+ * Author: Peng Zhang <zhangpeng.00@bytedance.com>
  */
 
 /*
@@ -6475,6 +6479,278 @@ void *mtree_erase(struct maple_tree *mt, unsigned long index)
 }
 EXPORT_SYMBOL(mtree_erase);
 
+/*
+ * mas_dup_free() - Free an incomplete duplication of a tree.
+ * @mas: The maple state of a incomplete tree.
+ *
+ * The parameter @mas->node passed in indicates that the allocation failed on
+ * this node. This function frees all nodes starting from @mas->node in the
+ * reverse order of mas_dup_build(). There is no need to hold the source tree
+ * lock at this time.
+ */
+static void mas_dup_free(struct ma_state *mas)
+{
+	struct maple_node *node;
+	enum maple_type type;
+	void __rcu **slots;
+	unsigned char count, i;
+
+	/* Maybe the first node allocation failed. */
+	if (mas_is_none(mas))
+		return;
+
+	while (!mte_is_root(mas->node)) {
+		mas_ascend(mas);
+		if (mas->offset) {
+			mas->offset--;
+			do {
+				mas_descend(mas);
+				mas->offset = mas_data_end(mas);
+			} while (!mte_is_leaf(mas->node));
+
+			mas_ascend(mas);
+		}
+
+		node = mte_to_node(mas->node);
+		type = mte_node_type(mas->node);
+		slots = ma_slots(node, type);
+		count = mas_data_end(mas) + 1;
+		for (i = 0; i < count; i++)
+			((unsigned long *)slots)[i] &= ~MAPLE_NODE_MASK;
+		mt_free_bulk(count, slots);
+	}
+
+	node = mte_to_node(mas->node);
+	mt_free_one(node);
+}
+
+/*
+ * mas_copy_node() - Copy a maple node and replace the parent.
+ * @mas: The maple state of source tree.
+ * @new_mas: The maple state of new tree.
+ * @parent: The parent of the new node.
+ *
+ * Copy @mas->node to @new_mas->node, set @parent to be the parent of
+ * @new_mas->node. If memory allocation fails, @mas is set to -ENOMEM.
+ */
+static inline void mas_copy_node(struct ma_state *mas, struct ma_state *new_mas,
+		struct maple_pnode *parent)
+{
+	struct maple_node *node = mte_to_node(mas->node);
+	struct maple_node *new_node = mte_to_node(new_mas->node);
+	unsigned long val;
+
+	/* Copy the node completely. */
+	memcpy(new_node, node, sizeof(struct maple_node));
+	/* Update the parent node pointer. */
+	val = (unsigned long)node->parent & MAPLE_NODE_MASK;
+	new_node->parent = ma_parent_ptr(val | (unsigned long)parent);
+}
+
+/*
+ * mas_dup_alloc() - Allocate child nodes for a maple node.
+ * @mas: The maple state of source tree.
+ * @new_mas: The maple state of new tree.
+ * @gfp: The GFP_FLAGS to use for allocations.
+ *
+ * This function allocates child nodes for @new_mas->node during the duplication
+ * process. If memory allocation fails, @mas is set to -ENOMEM.
+ */
+static inline void mas_dup_alloc(struct ma_state *mas, struct ma_state *new_mas,
+		gfp_t gfp)
+{
+	struct maple_node *node = mte_to_node(mas->node);
+	struct maple_node *new_node = mte_to_node(new_mas->node);
+	enum maple_type type;
+	unsigned char request, count, i;
+	void __rcu **slots;
+	void __rcu **new_slots;
+	unsigned long val;
+
+	/* Allocate memory for child nodes. */
+	type = mte_node_type(mas->node);
+	new_slots = ma_slots(new_node, type);
+	request = mas_data_end(mas) + 1;
+	count = mt_alloc_bulk(gfp, request, (void **)new_slots);
+	if (unlikely(count < request)) {
+		memset(new_slots, 0, request * sizeof(void *));
+		mas_set_err(mas, -ENOMEM);
+		return;
+	}
+
+	/* Restore node type information in slots. */
+	slots = ma_slots(node, type);
+	for (i = 0; i < count; i++) {
+		val = (unsigned long)mt_slot_locked(mas->tree, slots, i);
+		val &= MAPLE_NODE_MASK;
+		((unsigned long *)new_slots)[i] |= val;
+	}
+}
+
+/*
+ * mas_dup_build() - Build a new maple tree from a source tree
+ * @mas: The maple state of source tree, need to be in MAS_START state.
+ * @new_mas: The maple state of new tree, need to be in MAS_START state.
+ * @gfp: The GFP_FLAGS to use for allocations.
+ *
+ * This function builds a new tree in DFS preorder. If the memory allocation
+ * fails, the error code -ENOMEM will be set in @mas, and @new_mas points to the
+ * last node. mas_dup_free() will free the incomplete duplication of a tree.
+ *
+ * Note that the attributes of the two trees need to be exactly the same, and the
+ * new tree needs to be empty, otherwise -EINVAL will be set in @mas.
+ */
+static inline void mas_dup_build(struct ma_state *mas, struct ma_state *new_mas,
+		gfp_t gfp)
+{
+	struct maple_node *node;
+	struct maple_pnode *parent = NULL;
+	struct maple_enode *root;
+	enum maple_type type;
+
+	if (unlikely(mt_attr(mas->tree) != mt_attr(new_mas->tree)) ||
+	    unlikely(!mtree_empty(new_mas->tree))) {
+		mas_set_err(mas, -EINVAL);
+		return;
+	}
+
+	root = mas_start(mas);
+	if (mas_is_ptr(mas) || mas_is_none(mas))
+		goto set_new_tree;
+
+	node = mt_alloc_one(gfp);
+	if (!node) {
+		new_mas->node = MAS_NONE;
+		mas_set_err(mas, -ENOMEM);
+		return;
+	}
+
+	type = mte_node_type(mas->node);
+	root = mt_mk_node(node, type);
+	new_mas->node = root;
+	new_mas->min = 0;
+	new_mas->max = ULONG_MAX;
+	root = mte_mk_root(root);
+	while (1) {
+		mas_copy_node(mas, new_mas, parent);
+		if (!mte_is_leaf(mas->node)) {
+			/* Only allocate child nodes for non-leaf nodes. */
+			mas_dup_alloc(mas, new_mas, gfp);
+			if (unlikely(mas_is_err(mas)))
+				return;
+		} else {
+			/*
+			 * This is the last leaf node and duplication is
+			 * completed.
+			 */
+			if (mas->max == ULONG_MAX)
+				goto done;
+
+			/* This is not the last leaf node and needs to go up. */
+			do {
+				mas_ascend(mas);
+				mas_ascend(new_mas);
+			} while (mas->offset == mas_data_end(mas));
+
+			/* Move to the next subtree. */
+			mas->offset++;
+			new_mas->offset++;
+		}
+
+		mas_descend(mas);
+		parent = ma_parent_ptr(mte_to_node(new_mas->node));
+		mas_descend(new_mas);
+		mas->offset = 0;
+		new_mas->offset = 0;
+	}
+done:
+	/* Specially handle the parent of the root node. */
+	mte_to_node(root)->parent = ma_parent_ptr(mas_tree_parent(new_mas));
+set_new_tree:
+	/* Make them the same height */
+	new_mas->tree->ma_flags = mas->tree->ma_flags;
+	rcu_assign_pointer(new_mas->tree->ma_root, root);
+}
+
+/**
+ * __mt_dup(): Duplicate an entire maple tree
+ * @mt: The source maple tree
+ * @new: The new maple tree
+ * @gfp: The GFP_FLAGS to use for allocations
+ *
+ * This function duplicates a maple tree in Depth-First Search (DFS) pre-order
+ * traversal. It uses memcpy() to copy nodes in the source tree and allocate
+ * new child nodes in non-leaf nodes. The new node is exactly the same as the
+ * source node except for all the addresses stored in it. It will be faster than
+ * traversing all elements in the source tree and inserting them one by one into
+ * the new tree.
+ * The user needs to ensure that the attributes of the source tree and the new
+ * tree are the same, and the new tree needs to be an empty tree, otherwise
+ * -EINVAL will be returned.
+ * Note that the user needs to manually lock the source tree and the new tree.
+ *
+ * Return: 0 on success, -ENOMEM if memory could not be allocated, -EINVAL If
+ * the attributes of the two trees are different or the new tree is not an empty
+ * tree.
+ */
+int __mt_dup(struct maple_tree *mt, struct maple_tree *new, gfp_t gfp)
+{
+	int ret = 0;
+	MA_STATE(mas, mt, 0, 0);
+	MA_STATE(new_mas, new, 0, 0);
+
+	mas_dup_build(&mas, &new_mas, gfp);
+	if (unlikely(mas_is_err(&mas))) {
+		ret = xa_err(mas.node);
+		if (ret == -ENOMEM)
+			mas_dup_free(&new_mas);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(__mt_dup);
+
+/**
+ * mtree_dup(): Duplicate an entire maple tree
+ * @mt: The source maple tree
+ * @new: The new maple tree
+ * @gfp: The GFP_FLAGS to use for allocations
+ *
+ * This function duplicates a maple tree in Depth-First Search (DFS) pre-order
+ * traversal. It uses memcpy() to copy nodes in the source tree and allocate
+ * new child nodes in non-leaf nodes. The new node is exactly the same as the
+ * source node except for all the addresses stored in it. It will be faster than
+ * traversing all elements in the source tree and inserting them one by one into
+ * the new tree.
+ * The user needs to ensure that the attributes of the source tree and the new
+ * tree are the same, and the new tree needs to be an empty tree, otherwise
+ * -EINVAL will be returned.
+ *
+ * Return: 0 on success, -ENOMEM if memory could not be allocated, -EINVAL If
+ * the attributes of the two trees are different or the new tree is not an empty
+ * tree.
+ */
+int mtree_dup(struct maple_tree *mt, struct maple_tree *new, gfp_t gfp)
+{
+	int ret = 0;
+	MA_STATE(mas, mt, 0, 0);
+	MA_STATE(new_mas, new, 0, 0);
+
+	mas_lock(&new_mas);
+	mas_lock_nested(&mas, SINGLE_DEPTH_NESTING);
+	mas_dup_build(&mas, &new_mas, gfp);
+	mas_unlock(&mas);
+	if (unlikely(mas_is_err(&mas))) {
+		ret = xa_err(mas.node);
+		if (ret == -ENOMEM)
+			mas_dup_free(&new_mas);
+	}
+
+	mas_unlock(&new_mas);
+	return ret;
+}
+EXPORT_SYMBOL(mtree_dup);
+
 /**
  * __mt_destroy() - Walk and free all nodes of a locked maple tree.
  * @mt: The maple tree
