linux-kernel - [PATCH v2 5/5] maple_tree: Simplify mas_leaf_set

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Message-Id: <20231120070937.35481-6-zhangpeng.00@bytedance.com>
Date:   Mon, 20 Nov 2023 15:09:37 +0800
From:   Peng Zhang <zhangpeng.00@...edance.com>
To:     Liam.Howlett@...cle.com, dan.carpenter@...aro.org,
        akpm@...ux-foundation.org
Cc:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        maple-tree@...ts.infradead.org,
        Peng Zhang <zhangpeng.00@...edance.com>
Subject: [PATCH v2 5/5] maple_tree: Simplify mas_leaf_set_meta()

Now it seems that the incoming 'end' is already pointing to the last item,
so we can simplify this function, considering only whether the last slot is
being used. This has passed the maple tree test suite.

Signed-off-by: Peng Zhang <zhangpeng.00@...edance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
 lib/maple_tree.c | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index bf64d080b376..89f8d2160277 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1964,27 +1964,13 @@ static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start,
 
 /*
  * mas_leaf_set_meta() - Set the metadata of a leaf if possible.
- * @mas: The maple state
  * @node: The maple node
- * @pivots: pointer to the maple node pivots
  * @mt: The maple type
- * @end: The assumed end
- *
- * Note, end may be incremented within this function but not modified at the
- * source.  This is fine since the metadata is the last thing to be stored in a
- * node during a write.
+ * @end: The node end
  */
-static inline void mas_leaf_set_meta(struct ma_state *mas,
-		struct maple_node *node, unsigned long *pivots,
+static inline void mas_leaf_set_meta(struct maple_node *node,
 		enum maple_type mt, unsigned char end)
 {
-	/* There is no room for metadata already */
-	if (mt_pivots[mt] <= end)
-		return;
-
-	if (pivots[end] && pivots[end] < mas->max)
-		end++;
-
 	if (end < mt_slots[mt] - 1)
 		ma_set_meta(node, mt, 0, end);
 }
@@ -2041,7 +2027,7 @@ static inline void mab_mas_cp(struct maple_big_node *b_node,
 
 		ma_set_meta(node, mt, offset, end);
 	} else {
-		mas_leaf_set_meta(mas, node, pivots, mt, end);
+		mas_leaf_set_meta(node, mt, end);
 	}
 }
 
@@ -3962,7 +3948,7 @@ static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas,
 		dst_pivots[new_end] = mas->max;
 
 done:
-	mas_leaf_set_meta(mas, newnode, dst_pivots, maple_leaf_64, new_end);
+	mas_leaf_set_meta(newnode, maple_leaf_64, new_end);
 	if (in_rcu) {
 		struct maple_enode *old_enode = mas->node;
 
-- 
2.20.1