SUNRPC: Add a helper to apply a function to all the rpc_clnt's transports
Add a helper for tasks that require us to apply a function to all the
transports in an rpc_clnt.
An example of a usecase would be BIND_CONN_TO_SESSION, where we want
to send one RPC call down each transport.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 8e46fa5..19feb4d 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -736,6 +736,57 @@
}
EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
+static
+int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
+{
+ struct rpc_xprt_switch *xps;
+
+ rcu_read_lock();
+ xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
+ rcu_read_unlock();
+ if (xps == NULL)
+ return -EAGAIN;
+ xprt_iter_init_listall(xpi, xps);
+ xprt_switch_put(xps);
+ return 0;
+}
+
+/**
+ * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
+ * @clnt: pointer to client
+ * @fn: function to apply
+ * @data: void pointer to function data
+ *
+ * Iterates through the list of RPC transports currently attached to the
+ * client and applies the function fn(clnt, xprt, data).
+ *
+ * On error, the iteration stops, and the function returns the error value.
+ */
+int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
+ int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
+ void *data)
+{
+ struct rpc_xprt_iter xpi;
+ int ret;
+
+ ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
+ if (ret)
+ return ret;
+ for (;;) {
+ struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
+
+ if (!xprt)
+ break;
+ ret = fn(clnt, xprt, data);
+ xprt_put(xprt);
+ if (ret < 0)
+ break;
+ }
+ xprt_iter_destroy(&xpi);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
+
/*
* Kill all tasks for the given client.
* XXX: kill their descendants as well?
