From 20b20162e1f3b7e60cf0e79116fb2f3bdef3dc5e Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Fri, 30 Jan 2026 15:59:21 -0500 Subject: [PATCH] maple_tree: add gap support, slot and pivot sizes for maple copy Add plumbing work for using maple copy as a normal node for a source of copy operations. This is needed later. Link: https://lkml.kernel.org/r/20260130205935.2559335-17-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: Alice Ryhl Cc: Andrew Ballance Cc: Arnd Bergmann Cc: Christian Kujau Cc: Geert Uytterhoeven Cc: Kuninori Morimoto Cc: Matthew Wilcox (Oracle) Cc: SeongJae Park Cc: Sidhartha Kumar Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/maple_tree.h | 1 + lib/maple_tree.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h index e99e16ac1c6d..db6a02788902 100644 --- a/include/linux/maple_tree.h +++ b/include/linux/maple_tree.h @@ -165,6 +165,7 @@ struct maple_copy { } src[4]; /* Simulated node */ void __rcu *slot[3]; + unsigned long gap[3]; unsigned long min; union { unsigned long pivot[3]; diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 499cae720251..9c701ee7412c 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -101,6 +101,7 @@ static const unsigned long mt_max[] = { [maple_leaf_64] = ULONG_MAX, [maple_range_64] = ULONG_MAX, [maple_arange_64] = ULONG_MAX, + [maple_copy] = ULONG_MAX, }; #define mt_node_max(x) mt_max[mte_node_type(x)] #endif @@ -110,6 +111,7 @@ static const unsigned char mt_slots[] = { [maple_leaf_64] = MAPLE_RANGE64_SLOTS, [maple_range_64] = MAPLE_RANGE64_SLOTS, [maple_arange_64] = MAPLE_ARANGE64_SLOTS, + [maple_copy] = 3, }; #define mt_slot_count(x) mt_slots[mte_node_type(x)] @@ -118,6 +120,7 @@ static const unsigned char mt_pivots[] = { [maple_leaf_64] = MAPLE_RANGE64_SLOTS - 1, [maple_range_64] = MAPLE_RANGE64_SLOTS - 1, [maple_arange_64] = MAPLE_ARANGE64_SLOTS - 1, + [maple_copy] = 3, }; #define mt_pivot_count(x) mt_pivots[mte_node_type(x)] @@ -126,6 +129,7 @@ static const unsigned char mt_min_slots[] = { [maple_leaf_64] = (MAPLE_RANGE64_SLOTS / 2) - 2, [maple_range_64] = (MAPLE_RANGE64_SLOTS / 2) - 2, [maple_arange_64] = (MAPLE_ARANGE64_SLOTS / 2) - 1, + [maple_copy] = 1, /* Should never be used */ }; #define mt_min_slot_count(x) mt_min_slots[mte_node_type(x)] @@ -627,6 +631,7 @@ static inline unsigned long *ma_gaps(struct maple_node *node, case maple_arange_64: return node->ma64.gap; case maple_copy: + return node->cp.gap; case maple_range_64: case maple_leaf_64: case maple_dense: -- 2.47.3