maple_tree: preserve the tree attributes when destroying maple tree

When destroying maple tree, preserve its attributes and then turn it into
an empty tree.  This allows it to be reused without needing to be
reinitialized.

Link: https://lkml.kernel.org/r/20231027033845.90608-10-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 718a222cc09082ba3abd7578bd9e5a6c9b811f9e..4439469442c7bcfb3366fc7a23b5c4b8e933fb87 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -6763,7 +6763,7 @@ void __mt_destroy(struct maple_tree *mt)
        if (xa_is_node(root))
                mte_destroy_walk(root, mt);
 
-       mt->ma_flags = 0;
+       mt->ma_flags = mt_attr(mt);
 }
 EXPORT_SYMBOL_GPL(__mt_destroy);