在 2023/10/16 22:10, Matthew Wilcox 写道:
On Mon, Oct 16, 2023 at 11:22:19AM +0800, Peng Zhang wrote:
+++ b/lib/maple_tree.c
@@ -4,6 +4,10 @@
* Copyright (c) 2018-2022 Oracle Corporation
* Authors: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
* Matthew Wilcox <willy@xxxxxxxxxxxxx>
+ *
+ * Algorithm for duplicating Maple Tree
+ * Copyright (c) 2023 ByteDance
+ * Author: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
You can't copyright an algorithm. You can copyright the
_implementation_ of an algorithm. You have a significant chunk of code
in this file, so adding your copyright is reasonable (although not
legally required, AIUI). Just leave out this line:
+ * Algorithm for duplicating Maple Tree
Okay, I will make the correction, thank you.
+/**
+ * __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 memcopy() to copy nodes in the source tree and allocate
memcpy()?
Yes, thank you for pointing this out.
+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);
Why does it need to be exported?
I consider __mt_dup() as a general interface for Maple Tree,
uncertain whether it will be used by certain modules in the future.
