by Trond Myklebust

[permalink] [raw]

Subject: [RFC PATCH v2 12/13] SUNRPC: Allow addition of new transports to a struct rpc_clnt

Add a function to allow creation and addition of a new transport
to an existing rpc_clnt

Signed-off-by: Trond Myklebust <[email protected]>
---
include/linux/sunrpc/clnt.h | 11 ++++
net/sunrpc/clnt.c | 133 +++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 142 insertions(+), 2 deletions(-)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index d6510f64a361..9a7ddbaf116e 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -186,6 +186,17 @@ int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
void *data);

+int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
+ struct rpc_xprt_switch *xps,
+ struct rpc_xprt *xprt,
+ void *dummy);
+int rpc_clnt_add_xprt(struct rpc_clnt *, struct xprt_create *,
+ int (*setup)(struct rpc_clnt *,
+ struct rpc_xprt_switch *,
+ struct rpc_xprt *,
+ void *),
+ void *data);
+
const char *rpc_proc_name(const struct rpc_task *task);
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_CLNT_H */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index e19cac509cec..748846909919 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2490,7 +2490,10 @@ static int rpc_ping(struct rpc_clnt *clnt)
return err;
}

-struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
+static
+struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
+ struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
+ const struct rpc_call_ops *ops, void *data)
{
struct rpc_message msg = {
.rpc_proc = &rpcproc_null,
@@ -2498,14 +2501,140 @@ struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int
};
struct rpc_task_setup task_setup_data = {
.rpc_client = clnt,
+ .rpc_xprt = xprt,
.rpc_message = &msg,
- .callback_ops = &rpc_default_ops,
+ .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
+ .callback_data = data,
.flags = flags,
};
+
return rpc_run_task(&task_setup_data);
}
+
+struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
+{
+ return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
+}
EXPORT_SYMBOL_GPL(rpc_call_null);

+struct rpc_cb_add_xprt_calldata {
+ struct rpc_xprt_switch *xps;
+ struct rpc_xprt *xprt;
+};
+
+static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
+{
+ struct rpc_cb_add_xprt_calldata *data = calldata;
+
+ if (task->tk_status == 0)
+ rpc_xprt_switch_add_xprt(data->xps, data->xprt);
+}
+
+static void rpc_cb_add_xprt_release(void *calldata)
+{
+ struct rpc_cb_add_xprt_calldata *data = calldata;
+
+ xprt_put(data->xprt);
+ xprt_switch_put(data->xps);
+ kfree(data);
+}
+
+const static struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
+ .rpc_call_done = rpc_cb_add_xprt_done,
+ .rpc_release = rpc_cb_add_xprt_release,
+};
+
+/**
+ * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
+ * @clnt: pointer to struct rpc_clnt
+ * @xps: pointer to struct rpc_xprt_switch,
+ * @xprt: pointer struct rpc_xprt
+ * @dummy: unused
+ */
+int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
+ struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
+ void *dummy)
+{
+ struct rpc_cb_add_xprt_calldata *data;
+ struct rpc_cred *cred;
+ struct rpc_task *task;
+
+ data = kmalloc(sizeof(*data), GFP_NOFS);
+ if (!data)
+ return -ENOMEM;
+ data->xps = xprt_switch_get(xps);
+ data->xprt = xprt_get(xprt);
+
+ cred = authnull_ops.lookup_cred(NULL, NULL, 0);
+ task = rpc_call_null_helper(clnt, xprt, cred,
+ RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
+ &rpc_cb_add_xprt_call_ops, data);
+ put_rpccred(cred);
+ if (IS_ERR(task))
+ return PTR_ERR(task);
+ rpc_put_task(task);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
+
+/**
+ * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
+ * @clnt: pointer to struct rpc_clnt
+ * @args: pointer to struct xprt_create
+ * @setup: callback to test and/or set up the connection
+ * @data: pointer to setup function data
+ *
+ * Creates a new transport using the parameters set in args and
+ * adds it to clnt.
+ * If ping is set, then test that connectivity succeeds before
+ * adding the new transport.
+ *
+ */
+int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
+ struct xprt_create *xprtargs,
+ int (*setup)(struct rpc_clnt *,
+ struct rpc_xprt_switch *,
+ struct rpc_xprt *,
+ void *),
+ void *data)
+{
+ struct rpc_xprt_switch *xps;
+ struct rpc_xprt *xprt;
+ unsigned char resvport;
+ int ret = 0;
+
+ rcu_read_lock();
+ xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
+ xprt = xprt_iter_xprt(&clnt->cl_xpi);
+ if (xps == NULL || xprt == NULL) {
+ rcu_read_unlock();
+ return -EAGAIN;
+ }
+ resvport = xprt->resvport;
+ rcu_read_unlock();
+
+ xprt = xprt_create_transport(xprtargs);
+ if (IS_ERR(xprt)) {
+ ret = PTR_ERR(xprt);
+ goto out_put_switch;
+ }
+ xprt->resvport = resvport;
+
+ rpc_xprt_switch_set_roundrobin(xps);
+ if (setup) {
+ ret = setup(clnt, xps, xprt, data);
+ if (ret != 0)
+ goto out_put_xprt;
+ }
+ rpc_xprt_switch_add_xprt(xps, xprt);
+out_put_xprt:
+ xprt_put(xprt);
+out_put_switch:
+ xprt_switch_put(xps);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
+
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
static void rpc_show_header(void)
{
--
2.5.0