From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Fri, 30 Jan 2026 20:59:20 +0000 (-0500)
Subject: maple_tree: introduce ma_leaf_max_gap()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=de7f3ed37c1a433b7e1d5514e9a86a6c354e83d7;p=thirdparty%2Flinux.git

maple_tree: introduce ma_leaf_max_gap()

This is the same as mas_leaf_max_gap(), but the information necessary is
known without a maple state in future code.  Adding this function now
simplifies the review for a subsequent patch.

Link: https://lkml.kernel.org/r/20260130205935.2559335-16-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andrew Ballance <andrewjballance@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 0d6f810a4a1fc..499cae720251f 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1315,26 +1315,14 @@ void wr_mas_setup(struct ma_wr_state *wr_mas, struct ma_state *mas)
 	wr_mas->r_max = mas_safe_pivot(mas, wr_mas->pivots, mas->offset,
 				       wr_mas->type);
 }
-
-/*
- * mas_leaf_max_gap() - Returns the largest gap in a leaf node
- * @mas: the maple state
- *
- * Return: The maximum gap in the leaf.
- */
-static unsigned long mas_leaf_max_gap(struct ma_state *mas)
+static inline unsigned long ma_leaf_max_gap(struct maple_node *mn,
+		enum maple_type mt, unsigned long min, unsigned long max,
+		unsigned long *pivots, void __rcu **slots)
 {
-	enum maple_type mt;
 	unsigned long pstart, gap, max_gap;
-	struct maple_node *mn;
-	unsigned long *pivots;
-	void __rcu **slots;
 	unsigned char i;
 	unsigned char max_piv;
 
-	mt = mte_node_type(mas->node);
-	mn = mas_mn(mas);
-	slots = ma_slots(mn, mt);
 	max_gap = 0;
 	if (unlikely(ma_is_dense(mt))) {
 		gap = 0;
@@ -1356,26 +1344,25 @@ static unsigned long mas_leaf_max_gap(struct ma_state *mas)
 	 * Check the first implied pivot optimizes the loop below and slot 1 may
 	 * be skipped if there is a gap in slot 0.
 	 */
-	pivots = ma_pivots(mn, mt);
 	if (likely(!slots[0])) {
-		max_gap = pivots[0] - mas->min + 1;
+		max_gap = pivots[0] - min + 1;
 		i = 2;
 	} else {
 		i = 1;
 	}
 
 	/* reduce max_piv as the special case is checked before the loop */
-	max_piv = ma_data_end(mn, mt, pivots, mas->max) - 1;
+	max_piv = ma_data_end(mn, mt, pivots, max) - 1;
 	/*
 	 * Check end implied pivot which can only be a gap on the right most
 	 * node.
 	 */
-	if (unlikely(mas->max == ULONG_MAX) && !slots[max_piv + 1]) {
+	if (unlikely(max == ULONG_MAX) && !slots[max_piv + 1]) {
 		gap = ULONG_MAX - pivots[max_piv];
 		if (gap > max_gap)
 			max_gap = gap;
 
-		if (max_gap > pivots[max_piv] - mas->min)
+		if (max_gap > pivots[max_piv] - min)
 			return max_gap;
 	}
 
@@ -1395,6 +1382,27 @@ static unsigned long mas_leaf_max_gap(struct ma_state *mas)
 	return max_gap;
 }
 
+/*
+ * mas_leaf_max_gap() - Returns the largest gap in a leaf node
+ * @mas: the maple state
+ *
+ * Return: The maximum gap in the leaf.
+ */
+static inline unsigned long mas_leaf_max_gap(struct ma_state *mas)
+{
+	enum maple_type mt;
+	struct maple_node *mn;
+	unsigned long *pivots;
+	void __rcu **slots;
+
+	mn = mas_mn(mas);
+	mt = mte_node_type(mas->node);
+	slots = ma_slots(mn, mt);
+	pivots = ma_pivots(mn, mt);
+
+	return ma_leaf_max_gap(mn, mt, mas->min, mas->max, pivots, slots);
+}
+
 /*
  * ma_max_gap() - Get the maximum gap in a maple node (non-leaf)
  * @node: The maple node