[RESEND,v2,0/3] maple_tree: Fix the replacement of a root leaf node

Message

Wei Yang April 7, 2025, 11:13 p.m. UTC

On destroy we should set each node dead. But current
code miss this when the maple tree has only the root node.

The reason is mt_destroy_walk() leverage mte_destroy_descend() to set
node dead, but this is skipped since the only root node is a leaf.

Patch 1 fixes this.

When adding a test case, I found we always get the new value even we leave the
old root node not dead. It turns out we always re-walk the tree in mas_walk().
It looks like a typo on the status check of mas_walk().

Patch 2 fixes this.

Patch 3 add a test case to assert retrieving new value when overwriting the
whole range to a tree with only root node.

Wei Yang (3):
  maple_tree: Fix mt_destroy_walk() on root leaf node
  maple_tree: restart walk on correct status
  maple_tree: assert retrieving new value on a tree containing just a
    leaf node

 lib/maple_tree.c                 |  3 ++-
 tools/testing/radix-tree/maple.c | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)