1 files changed, 56 insertions, 0 deletions
diff --git a/lib/test_maple_tree.c b/lib/test_maple_tree.c
index 704cb1093ae8..13e2a10d7554 100644
--- a/lib/test_maple_tree.c
+++ b/lib/test_maple_tree.c
@@ -1563,6 +1563,30 @@ static noinline void __init check_root_expand(struct maple_tree *mt)
 	mas_unlock(&mas);
 }
 
+static noinline void __init check_deficient_node(struct maple_tree *mt)
+{
+	MA_STATE(mas, mt, 0, 0);
+	int count;
+
+	mas_lock(&mas);
+	for (count = 0; count < 10; count++) {
+		mas_set(&mas, count);
+		mas_store_gfp(&mas, xa_mk_value(count), GFP_KERNEL);
+	}
+
+	for (count = 20; count < 39; count++) {
+		mas_set(&mas, count);
+		mas_store_gfp(&mas, xa_mk_value(count), GFP_KERNEL);
+	}
+
+	for (count = 10; count < 12; count++) {
+		mas_set(&mas, count);
+		mas_store_gfp(&mas, xa_mk_value(count), GFP_KERNEL);
+	}
+	mas_unlock(&mas);
+	mt_validate(mt);
+}
+
 static noinline void __init check_gap_combining(struct maple_tree *mt)
 {
 	struct maple_enode *mn1, *mn2;
@@ -3714,6 +3738,34 @@ static noinline void __init alloc_cyclic_testing(struct maple_tree *mt)
 	}
 
 	mtree_destroy(mt);
+
+	/*
+	 * Issue with reverse search was discovered
+	 * https://lore.kernel.org/all/20241216060600.287B4C4CED0@smtp.kernel.org/
+	 * Exhausting the allocation area and forcing the search to wrap needs a
+	 * mas_reset() in mas_alloc_cyclic().
+	 */
+	next = 0;
+	mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE);
+	for (int i = 0; i < 1023; i++) {
+		mtree_alloc_cyclic(mt, &location, mt, 2, 1024, &next, GFP_KERNEL);
+		MT_BUG_ON(mt, i != location - 2);
+		MT_BUG_ON(mt, i != next - 3);
+		MT_BUG_ON(mt, mtree_load(mt, location) != mt);
+	}
+	mtree_erase(mt, 123);
+	MT_BUG_ON(mt, mtree_load(mt, 123) != NULL);
+	mtree_alloc_cyclic(mt, &location, mt, 2, 1024, &next, GFP_KERNEL);
+	MT_BUG_ON(mt, 123 != location);
+	MT_BUG_ON(mt, 124 != next);
+	MT_BUG_ON(mt, mtree_load(mt, location) != mt);
+	mtree_erase(mt, 100);
+	mtree_alloc_cyclic(mt, &location, mt, 2, 1024, &next, GFP_KERNEL);
+	MT_BUG_ON(mt, 100 != location);
+	MT_BUG_ON(mt, 101 != next);
+	MT_BUG_ON(mt, mtree_load(mt, location) != mt);
+	mtree_destroy(mt);
+
 	/* Overflow test */
 	next = ULONG_MAX - 1;
 	ret = mtree_alloc_cyclic(mt, &location, mt, 2, ULONG_MAX, &next, GFP_KERNEL);
@@ -3797,6 +3849,10 @@ static int __init maple_tree_seed(void)
 #endif
 
 	mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);
+	check_deficient_node(&tree);
+	mtree_destroy(&tree);
+
+	mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);
 	check_store_null(&tree);
 	mtree_destroy(&tree);