From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Fri, 10 Oct 2025 16:41:05 +0000 (-0400)
Subject: maple_tree: Add gap support, slot and pivot sizes for maple copy
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f14a02610b45872ebe934efb9e179fb383ca94d9;p=users%2Fjedix%2Flinux-maple.git

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.

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

diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index 9e3c0529b0a7..8f6fd30276b0 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -172,6 +172,7 @@ 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 b294a643e823..ba9007263e99 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -103,6 +103,7 @@ 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
@@ -112,6 +113,7 @@ 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)]
 
@@ -120,6 +122,7 @@ 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)]
 
@@ -128,6 +131,7 @@ 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)]
 
@@ -691,6 +695,7 @@ 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: