1 files changed, 10 insertions, 1 deletions
diff --git a/rust/kernel/maple_tree.rs b/rust/kernel/maple_tree.rs
index e72eec56bf57..265d6396a78a 100644
--- a/rust/kernel/maple_tree.rs
+++ b/rust/kernel/maple_tree.rs
@@ -265,7 +265,16 @@ impl<T: ForeignOwnable> MapleTree<T> {
         loop {
             // This uses the raw accessor because we're destroying pointers without removing them
             // from the maple tree, which is only valid because this is the destructor.
-            let ptr = ma_state.mas_find_raw(usize::MAX);
+            //
+            // Take the rcu lock because mas_find_raw() requires that you hold either the spinlock
+            // or the rcu read lock. This is only really required if memory reclaim might
+            // reallocate entries in the tree, as we otherwise have exclusive access. That feature
+            // doesn't exist yet, so for now, taking the rcu lock only serves the purpose of
+            // silencing lockdep.
+            let ptr = {
+                let _rcu = kernel::sync::rcu::Guard::new();
+                ma_state.mas_find_raw(usize::MAX)
+            };
             if ptr.is_null() {
                 break;
             }