From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Fri, 24 Sep 2021 18:22:10 +0000 (-0400)
Subject: maple_tree: Clean up mas_store_b_node
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=refs%2Fheads%2Fmaple_next_rcu;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Clean up mas_store_b_node

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 6083438538b2..897c21f39eac 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1966,29 +1966,31 @@ static inline void mas_bulk_rebalance(struct ma_state *mas, unsigned char end,
  */
 static inline unsigned char mas_store_b_node(struct ma_state *mas,
 				    struct maple_big_node *b_node,
-				    void *entry, unsigned char end)
+				    void *entry, unsigned char end,
+				    unsigned char offset_end,
+				    void *content)
 {
 	unsigned char slot = mas->offset;
-	void *contents;
-	unsigned char b_end = 0;
+	unsigned char b_end;
 	/* Possible underflow of piv will wrap back to 0 before use. */
-	unsigned long piv = mas->min - 1;
-	struct maple_node *node = mas_mn(mas);
-	enum maple_type mt = mte_node_type(mas->node);
-	unsigned long *pivots = ma_pivots(node, mt);
+	unsigned long piv;
+	struct maple_node *node;
+	enum maple_type mt;
+	unsigned long *pivots;
 
+	b_end = 0;
 	if (slot) {
 		/* Copy start data up to insert. */
 		mas_mab_cp(mas, 0, slot - 1, b_node, 0);
 		b_end = b_node->b_end;
 		piv = b_node->pivot[b_end - 1];
-	}
+	} else
+		piv = mas->min - 1;
 
-	contents = mas_slot_locked(mas, ma_slots(node, mt), slot);
 	if (piv + 1 < mas->index) {
 		/* Handle range starting after old range */
-		b_node->slot[b_end] = contents;
-		if (!contents)
+		b_node->slot[b_end] = content;
+		if (!content)
 			b_node->gap[b_end] = mas->index - 1 - piv;
 		b_node->pivot[b_end++] = mas->index - 1;
 	}
@@ -1998,39 +2000,38 @@ static inline unsigned char mas_store_b_node(struct ma_state *mas,
 	b_node->slot[b_end] = entry;
 	b_node->pivot[b_end] = mas->last;
 
+	/* Appended. */
+	if (mas->last >= mas->max)
+		return b_end;
+
 	/* Handle new range ending before old range ends */
-	piv = _mas_safe_pivot(mas, pivots, slot, mt);
+	node = mas_mn(mas);
+	mt = mte_node_type(mas->node);
+	pivots = ma_pivots(node, mt);
+	piv = mas_logical_pivot(mas, pivots, offset_end, mt);
 	if (piv > mas->last) {
 		if (piv == ULONG_MAX)
 			mas_bulk_rebalance(mas, b_node->b_end, mt);
 
-		b_node->slot[++b_end] = contents;
-		if (!contents)
+		if (offset_end != slot) {
+			void **slots = ma_slots(node, mt);
+
+			content = slots[offset_end];
+		}
+
+		b_node->slot[++b_end] = content;
+		if (!content)
 			b_node->gap[b_end] = piv - mas->last + 1;
 		b_node->pivot[b_end] = piv;
-	} else
-		piv = mas->last;
+	}
 
-	/* Appended. */
-	if (piv >= mas->max)
+	slot = offset_end + 1;
+	if (slot > end)
 		return b_end;
 
-	do {
-		/* Handle range overwrites */
-		piv = _mas_safe_pivot(mas, pivots, ++slot, mt);
-	} while ((piv <= mas->last) && (slot <= end));
-
-	if (piv > mas->last) {
-		/* Copy end data to the end of the node. */
-		if (slot > end) {
-			b_node->slot[++b_end] = NULL;
-			b_node->pivot[b_end] = piv;
-		} else {
-			mas_mab_cp(mas, slot, end + 1, b_node, ++b_end);
-			b_end = b_node->b_end - 1;
-		}
-	}
-
+	/* Copy end data to the end of the node. */
+	mas_mab_cp(mas, slot, end + 1, b_node, ++b_end);
+	b_end = b_node->b_end - 1;
 	return b_end;
 }
 
@@ -3303,13 +3304,11 @@ static inline int mas_commit_b_node(struct ma_state *mas,
 	}
 
 
-	if (b_end >= mt_slots[b_type]) {
+	if (b_end >= mt_slots[b_type])
 		return mas_split(mas, b_node);
-	}
 
-	if (mas_reuse_node(mas, b_node, end)) {
+	if (mas_reuse_node(mas, b_node, end))
 		goto reuse_node;
-	}
 
 	mas_node_count(mas, 1);
 	if (mas_is_err(mas))
@@ -3726,6 +3725,7 @@ static inline int mas_spanning_store(struct ma_state *mas, void *entry)
 	struct maple_subtree_state mast;
 	unsigned char height = mas_mt_height(mas);
 	int node_count = 1 + height * 3;
+	void *content;
 
 	/* Holds new left and right sub-tree */
 	MA_STATE(l_mas, mas->tree, mas->index, mas->index);
@@ -3765,6 +3765,7 @@ static inline int mas_spanning_store(struct ma_state *mas, void *entry)
 	l_mas.depth = mas->depth;
 	l_mas.offset = 0;
 	__mas_walk(&l_mas, &range_min, &range_max);
+	content = mas_get_slot(&l_mas, l_mas.offset);
 
 	if (!entry) {
 		mas_extend_null(&l_mas, &r_mas);
@@ -3776,7 +3777,8 @@ static inline int mas_spanning_store(struct ma_state *mas, void *entry)
 
 	/* Copy l_mas and store the value in b_node. */
 	b_node.b_end = mas_store_b_node(&l_mas, &b_node, entry,
-					mas_data_end(&l_mas));
+					mas_data_end(&l_mas), mas_data_end(&l_mas),
+					content);
 	/* Copy r_mas into b_node. */
 	mas_mab_cp(&r_mas, r_mas.offset, mt_slot_count(r_mas.node),
 		   &b_node, b_node.b_end + 1);
@@ -4139,7 +4141,7 @@ static inline void *_mas_store(struct ma_state *mas, void *entry, bool overwrite
 
 slow_path:
 	b_node.type = mte_node_type(mas->node);
-	b_node.b_end = mas_store_b_node(mas, &b_node, entry, end);
+	b_node.b_end = mas_store_b_node(mas, &b_node, entry, end, offset_end, content);
 	b_node.min = mas->min;
 
 	zero = MAPLE_BIG_NODE_SLOTS - b_node.b_end - 1;