From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Wed, 16 Apr 2025 15:54:58 +0000 (-0400)
Subject: code cleanup of try_rebalance
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4088a9ab8d5d800752a9d7fb591bc0ce5e49f14d;p=users%2Fjedix%2Flinux-maple.git

code cleanup of try_rebalance

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 158b6a676787..14666ff92a4a 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3965,6 +3965,7 @@ bool can_rebalance_right(struct ma_state *tmp_mas, struct ma_node_info *parent,
 		tmp_mas->offset--;
 		return false;
 	}
+
 	return true;
 }
 
@@ -4019,33 +4020,28 @@ bool mas_wr_try_rebalance(struct ma_state *mas, struct ma_node_info *src,
 
 	src->end = mas->end;
 	if (can_rebalance_left(&tmp_mas, &parent, &src2, sd)) {
+		/* Left will be src2, right will be src */
 		left->min = src2.min;
 		right->max = src->max;
+		/* Shift split data variables */
+		sd->insert = mas->offset + src2.end + 1;
+		sd->offset = src2.end + 1;
+		sd->space = sd->split - src2.end;
+		sd->states[sd->len].info = &src2;
+		/* The first state to copy is the left node */
+		mns_mni_init(&sd->states[sd->len], left, 0, src2.end + 1);
+		sd->len++;
 	} else if (can_rebalance_right(&tmp_mas, &parent, &src2, sd)) {
 		sd->split = src2.end + sd->new_end - sd->split;
 		left_store = true;
 		/* Left will be src, right will be src2 */
 		left->min = src->min;
 		right->max = src2.max;
-	} else {
-		return false;
-	}
-
-	/* The rebalance operation will succeed. */
-	sd->new_end += src2.end + 1;
-	if (left_store)  {
-		/* Left pushes data right. */
 		sd->insert = mas->offset;
 		sd->space = sd->split;
 		sd->offset = 0;
 	} else {
-		/* Right pushes data left */
-		sd->insert = mas->offset + src2.end + 1;
-		sd->offset = src2.end + 1;
-		sd->space = sd->split - src2.end;
-		sd->states[sd->len].info = &src2;
-		mns_mni_init(&sd->states[sd->len], left, 0, src2.end + 1);
-		sd->len++;
+		return false;
 	}
 
 	/*
@@ -4053,8 +4049,10 @@ bool mas_wr_try_rebalance(struct ma_state *mas, struct ma_node_info *src,
 	 * There can also be a split between nodes that may happen at these
 	 * boundaries, or elsewhere.
 	 */
+	sd->new_end += src2.end + 1;
 	mt_wr_split_data(src, left, right, part, sd);
 	if (left_store) {
+		/* Stored to the left, copy the last of the right in src2 */
 		sd->states[sd->len].info = &src2;
 		mns_mni_init(&sd->states[sd->len], right, 0, src2.end + 1);
 		sd->len++;