[merged mm-hotfixes-stable] test_maple_tree-add-more-testing-for-mas_empty_area.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: test_maple_tree: add more testing for mas_empty_area()
has been removed from the -mm tree.  Its filename was
     test_maple_tree-add-more-testing-for-mas_empty_area.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Subject: test_maple_tree: add more testing for mas_empty_area()
Date: Tue, 7 Mar 2023 13:02:47 -0500

Test robust filling of an entire area of the tree, then test one beyond. 
This is to test the walking back up the tree at the end of nodes and error
condition.  Test inspired by the reproducer code provided by Snild Dolkow.

The last test in the function tests for the case of a corrupted maple
state caused by the incorrect limits set during mas_skip_node().  There
needs to be a gap in the second last child and last child, but the search
must rule out the second last child's gap.  This would avoid correcting
the maple state to the correct max limit and return an error.

Link: https://lkml.kernel.org/r/20230307180247.2220303-3-Liam.Howlett@oracle.com
Cc: Snild Dolkow <snild@sony.com>
Link: https://lore.kernel.org/linux-mm/cb8dc31a-fef2-1d09-f133-e9f7b9f9e77a@sony.com/
Fixes: e15e06a83923 ("lib/test_maple_tree: add testing for maple tree")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/lib/test_maple_tree.c~test_maple_tree-add-more-testing-for-mas_empty_area
+++ a/lib/test_maple_tree.c
@@ -2670,6 +2670,49 @@ static noinline void check_empty_area_wi
 	rcu_read_unlock();
 }
 
+static noinline void check_empty_area_fill(struct maple_tree *mt)
+{
+	const unsigned long max = 0x25D78000;
+	unsigned long size;
+	int loop, shift;
+	MA_STATE(mas, mt, 0, 0);
+
+	mt_set_non_kernel(99999);
+	for (shift = 12; shift <= 16; shift++) {
+		loop = 5000;
+		size = 1 << shift;
+		while (loop--) {
+			mas_set(&mas, 0);
+			mas_lock(&mas);
+			MT_BUG_ON(mt, mas_empty_area(&mas, 0, max, size) != 0);
+			MT_BUG_ON(mt, mas.last != mas.index + size - 1);
+			mas_store_gfp(&mas, (void *)size, GFP_KERNEL);
+			mas_unlock(&mas);
+			mas_reset(&mas);
+		}
+	}
+
+	/* No space left. */
+	size = 0x1000;
+	rcu_read_lock();
+	MT_BUG_ON(mt, mas_empty_area(&mas, 0, max, size) != -EBUSY);
+	rcu_read_unlock();
+
+	/* Fill a depth 3 node to the maximum */
+	for (unsigned long i = 629440511; i <= 629440800; i += 6)
+		mtree_store_range(mt, i, i + 5, (void *)i, GFP_KERNEL);
+	/* Make space in the second-last depth 4 node */
+	mtree_erase(mt, 631668735);
+	/* Make space in the last depth 4 node */
+	mtree_erase(mt, 629506047);
+	mas_reset(&mas);
+	/* Search from just after the gap in the second-last depth 4 */
+	rcu_read_lock();
+	MT_BUG_ON(mt, mas_empty_area(&mas, 629506048, 690000000, 0x5000) != 0);
+	rcu_read_unlock();
+	mt_set_non_kernel(0);
+}
+
 static DEFINE_MTREE(tree);
 static int maple_tree_seed(void)
 {
@@ -2926,6 +2969,11 @@ static int maple_tree_seed(void)
 	check_empty_area_window(&tree);
 	mtree_destroy(&tree);
 
+	mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);
+	check_empty_area_fill(&tree);
+	mtree_destroy(&tree);
+
+
 #if defined(BENCH)
 skip:
 #endif
_

Patches currently in -mm which might be from Liam.Howlett@oracle.com are

maple_tree-be-more-cautious-about-dead-nodes.patch
maple_tree-detect-dead-nodes-in-mas_start.patch
maple_tree-fix-freeing-of-nodes-in-rcu-mode.patch
maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves.patch
maple_tree-fix-write-memory-barrier-of-nodes-once-dead-for-rcu-mode.patch
maple_tree-add-smp_rmb-to-dead-node-detection.patch
maple_tree-add-rcu-lock-checking-to-rcu-callback-functions.patch
mm-enable-maple-tree-rcu-mode-by-default.patch