XArray: Fix xa_erase of 2-byte aligned entries
xas_store() was interpreting the entry it found in the array as a node
entry if the bottom two bits had value 2. That's only true if either
the entry is in the root node or in a non-leaf node.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
diff --git a/lib/xarray.c b/lib/xarray.c
index 3f10198..2cc3798 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -800,7 +800,7 @@ void *xas_store(struct xa_state *xas, void *entry)
* entry is set to NULL.
*/
rcu_assign_pointer(*slot, entry);
- if (xa_is_node(next))
+ if (xa_is_node(next) && (!node || node->shift))
xas_free_nodes(xas, xa_to_node(next));
if (!node)
break;