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 0d6f810a4a1fc5432b2499c155e429240e84927d..499cae720251f3ebe0fc60878a3dc30c213bde05 100644 (file)
--- 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