nfsv3: introduce nfs3_set_ds_client

The flexfiles layout wants to create DS connection over NFSv3.
Add nfs3_set_ds_client to allow that to happen.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c
index 8c1b437c5403..52e2344bf9a1 100644
--- a/fs/nfs/nfs3client.c
+++ b/fs/nfs/nfs3client.c
@@ -64,3 +64,37 @@ struct nfs_server *nfs3_clone_server(struct nfs_server *source,
                 nfs_init_server_aclclient(server);
         return server;
 }
+
+/*
+ * Set up a pNFS Data Server client over NFSv3.
+ *
+ * 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 *nfs3_set_ds_client(struct nfs_client *mds_clp,
+                const struct sockaddr *ds_addr, int ds_addrlen,
+                int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
+                rpc_authflavor_t au_flavor)
+{
+        struct nfs_client_initdata cl_init = {
+                .addr = ds_addr,
+                .addrlen = ds_addrlen,
+                .nfs_mod = &nfs_v3,
+                .proto = ds_proto,
+                .net = mds_clp->cl_net,
+        };
+        struct rpc_timeout ds_timeout;
+        struct nfs_client *clp;
+
+        /* Use the MDS nfs_client cl_ipaddr. */
+        nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
+        clp = nfs_get_client(&cl_init, &ds_timeout, mds_clp->cl_ipaddr,
+                             au_flavor);
+
+        return clp;
+}
+EXPORT_SYMBOL_GPL(nfs3_set_ds_client);