+
+#if IS_ENABLED(CONFIG_SUNRPC_SWAP)
+int
+rpc_clnt_swap_activate(struct rpc_clnt *clnt)
+{
+ int ret = 0;
+ struct rpc_xprt *xprt;
+
+ if (atomic_inc_return(&clnt->cl_swapper) == 1) {
+retry:
+ rcu_read_lock();
+ xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
+ rcu_read_unlock();
+ if (!xprt) {
+ /*
+ * If we didn't get a reference, then we likely are
+ * racing with a migration event. Wait for a grace
+ * period and try again.
+ */
+ synchronize_rcu();
+ goto retry;
+ }
+
+ ret = xprt_enable_swap(xprt);
+ xprt_put(xprt);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
+
+void
+rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
+{
+ struct rpc_xprt *xprt;
+
+ if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) {
+retry:
+ rcu_read_lock();
+ xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
+ rcu_read_unlock();
+ if (!xprt) {
+ /*
+ * If we didn't get a reference, then we likely are
+ * racing with a migration event. Wait for a grace
+ * period and try again.
+ */
+ synchronize_rcu();
+ goto retry;
+ }
+
+ xprt_disable_swap(xprt);
+ xprt_put(xprt);
+ }
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
+#endif /* CONFIG_SUNRPC_SWAP */