XArray tests: Add missing locking

Lockdep caught me being sloppy in the test suite and failing to lock
the XArray appropriately.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>

lib/test_xarray.c

@@ -208,15 +208,19 @@ static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index)
 			XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_2));
 
 			/* We should see two elements in the array */
+			rcu_read_lock();
 			xas_for_each(&xas, entry, ULONG_MAX)
 				seen++;
+			rcu_read_unlock();
 			XA_BUG_ON(xa, seen != 2);
 
 			/* One of which is marked */
 			xas_set(&xas, 0);
 			seen = 0;
+			rcu_read_lock();
 			xas_for_each_marked(&xas, entry, ULONG_MAX, XA_MARK_0)
 				seen++;
+			rcu_read_unlock();
 			XA_BUG_ON(xa, seen != 1);
 		}
 		XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_0));
@@ -442,7 +446,9 @@ static noinline void check_multi_store_1(struct xarray *xa, unsigned long index,
 	XA_BUG_ON(xa, xa_load(xa, max) != NULL);
 	XA_BUG_ON(xa, xa_load(xa, min - 1) != NULL);
 
+	xas_lock(&xas);
 	XA_BUG_ON(xa, xas_store(&xas, xa_mk_value(min)) != xa_mk_value(index));
+	xas_unlock(&xas);
 	XA_BUG_ON(xa, xa_load(xa, min) != xa_mk_value(min));
 	XA_BUG_ON(xa, xa_load(xa, max - 1) != xa_mk_value(min));
 	XA_BUG_ON(xa, xa_load(xa, max) != NULL);
@@ -458,9 +464,11 @@ static noinline void check_multi_store_2(struct xarray *xa, unsigned long index,
 	XA_STATE(xas, xa, index);
 	xa_store_order(xa, index, order, xa_mk_value(0), GFP_KERNEL);
 
+	xas_lock(&xas);
 	XA_BUG_ON(xa, xas_store(&xas, xa_mk_value(1)) != xa_mk_value(0));
 	XA_BUG_ON(xa, xas.xa_index != index);
 	XA_BUG_ON(xa, xas_store(&xas, NULL) != xa_mk_value(1));
+	xas_unlock(&xas);
 	XA_BUG_ON(xa, !xa_empty(xa));
 }
 #endif
@@ -1180,10 +1188,12 @@ static noinline void check_account(struct xarray *xa)
 		XA_STATE(xas, xa, 1 << order);
 
 		xa_store_order(xa, 0, order, xa, GFP_KERNEL);
+		rcu_read_lock();
 		xas_load(&xas);
 		XA_BUG_ON(xa, xas.xa_node->count == 0);
 		XA_BUG_ON(xa, xas.xa_node->count > (1 << order));
 		XA_BUG_ON(xa, xas.xa_node->nr_values != 0);
+		rcu_read_unlock();
 
 		xa_store_order(xa, 1 << order, order, xa_mk_value(1 << order),
 				GFP_KERNEL);