+ maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch added to mm-new branch

+ maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: assert retrieving new value on a tree containing just a leaf node
has been added to the -mm mm-new branch.  Its filename is
     maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: maple_tree: assert retrieving new value on a tree containing just a leaf node
Date: Wed, 11 Jun 2025 01:12:53 +0000

Original code may not get the new value after overwriting the whole range
on a maple tree containing just a leaf node.  The reason is we didn't set
the only root node dead during destroy.

Add a test case to ensure the new value is returned when overwriting a
tree containing just a leaf node.

Link: https://lkml.kernel.org/r/20250611011253.19515-4-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/radix-tree/maple.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/tools/testing/radix-tree/maple.c~maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node
+++ a/tools/testing/radix-tree/maple.c
@@ -35256,6 +35256,30 @@ static noinline void __init check_rcu_si
 	MT_BUG_ON(mt, mas_prev(&mas_reader, 0) != xa_mk_value(val));
 	rcu_read_unlock();
 
+	/* Clear out tree & create one with only root node */
+	mas_lock(&mas_writer);
+	mas_set_range(&mas_writer, 0, ULONG_MAX);
+	mas_store_gfp(&mas_writer, NULL, GFP_KERNEL);
+	mas_set_range(&mas_writer, 0, 0);
+	for (i = 0; i <= 5; i++) {
+		mas_writer.index = i * 10;
+		mas_writer.last = i * 10 + 5;
+		mas_store_gfp(&mas_writer, xa_mk_value(i), GFP_KERNEL);
+	}
+	mas_unlock(&mas_writer);
+	target = 10;
+	mas_set_range(&mas_reader, target, target);
+	rcu_read_lock();
+	MT_BUG_ON(mt, mas_walk(&mas_reader) != xa_mk_value(target/10));
+
+	/* Overwrite the whole range */
+	mas_lock(&mas_writer);
+	mas_set_range(&mas_writer, 0, ULONG_MAX);
+	mas_store_gfp(&mas_writer, xa_mk_value(val), GFP_KERNEL);
+	mas_unlock(&mas_writer);
+	MT_BUG_ON(mt, mas_walk(&mas_reader) != xa_mk_value(val));
+	rcu_read_unlock();
+
 	rcu_unregister_thread();
 }
 
_

Patches currently in -mm which might be from richard.weiyang@gmail.com are

maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch
maple_tree-restart-walk-on-correct-status.patch
maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch

+ maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: assert retrieving new value on a tree containing just a leaf node
has been added to the -mm mm-new branch.  Its filename is
     maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: maple_tree: assert retrieving new value on a tree containing just a leaf node
Date: Tue, 24 Jun 2025 15:18:41 -0400

Original code may not get the new value after overwriting the whole range
on a maple tree containing just a leaf node.  The reason is we didn't set
the only root node dead during destroy.

Add a test case to ensure the new value is returned when overwriting a
tree containing just a leaf node.

[Liam.Howlett@oracle.com: use mtree_destroy, mas_set, and set val]
Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.com/
Link: https://lkml.kernel.org/r/20250624191841.64682-2-Liam.Howlett@oracle.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/radix-tree/maple.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

--- a/tools/testing/radix-tree/maple.c~maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node
+++ a/tools/testing/radix-tree/maple.c
@@ -35257,6 +35257,32 @@ static noinline void __init check_rcu_si
 	MT_BUG_ON(mt, mas_prev(&mas_reader, 0) != xa_mk_value(val));
 	rcu_read_unlock();
 
+	/* Clear out tree & create one with only root node */
+	mtree_destroy(mt);
+	mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_USE_RCU);
+	mas_pause(&mas_writer);
+	mas_lock(&mas_writer);
+	for (i = 0; i <= 5; i++) {
+		mas_writer.index = i * 10;
+		mas_writer.last = i * 10 + 5;
+		mas_store_gfp(&mas_writer, xa_mk_value(i), GFP_KERNEL);
+	}
+	mas_unlock(&mas_writer);
+	target = 10;
+	val = 20;
+	mas_set(&mas_reader, target);
+	rcu_read_lock();
+	MT_BUG_ON(mt, mas_walk(&mas_reader) != xa_mk_value(target/10));
+	MT_BUG_ON(mt, mte_is_leaf(mas_reader.node) != true);
+
+	/* Overwrite the whole range */
+	mas_lock(&mas_writer);
+	mas_set_range(&mas_writer, 0, ULONG_MAX);
+	mas_store_gfp(&mas_writer, xa_mk_value(val), GFP_KERNEL);
+	mas_unlock(&mas_writer);
+	MT_BUG_ON(mt, mas_walk(&mas_reader) != xa_mk_value(val));
+	rcu_read_unlock();
+
 	rcu_unregister_thread();
 }
 
_

Patches currently in -mm which might be from richard.weiyang@gmail.com are

maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch
maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch