1 files changed, 41 insertions, 0 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index d5c5bdfa4231..6dd50ac5b545 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1417,6 +1417,47 @@ error:
         return error;
 }
 
+/*
+ * Set up a pNFS Data Server client.
+ *
+ * Return any existing nfs_client that matches server address,port,version
+ * and minorversion.
+ *
+ * For a new nfs_client, use a soft mount (default), a low retrans and a
+ * low timeout interval so that if a connection is lost, we retry through
+ * the MDS.
+ */
+struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,
+                const struct sockaddr *ds_addr,
+                int ds_addrlen, int ds_proto)
+{
+        struct nfs_client_initdata cl_init = {
+                .addr = ds_addr,
+                .addrlen = ds_addrlen,
+                .rpc_ops = &nfs_v4_clientops,
+                .proto = ds_proto,
+                .minorversion = mds_clp->cl_minorversion,
+        };
+        struct rpc_timeout ds_timeout = {
+                .to_initval = 15 * HZ,
+                .to_maxval = 15 * HZ,
+                .to_retries = 1,
+                .to_exponential = 1,
+        };
+        struct nfs_client *clp;
+
+        /*
+         * Set an authflavor equual to the MDS value. Use the MDS nfs_client
+         * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
+         * (section 13.1 RFC 5661).
+         */
+        clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
+                             mds_clp->cl_rpcclient->cl_auth->au_flavor, 0);
+
+        dprintk("<-- %s %p\n", __func__, clp);
+        return clp;
+}
+EXPORT_SYMBOL(nfs4_set_ds_client);
 
 /*
  * Session has been established, and the client marked ready.