NFS: Add sysfs links to sunrpc clients for nfs_clients

For the general and state management nfs_client under each mount, create
symlinks to their respective rpc_client sysfs entries.

Signed-off-by: Benjamin Coddington <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/client.c

···
 	if (server->flags & NFS_MOUNT_SOFT)
 		server->client->cl_softrtry = 1;
 
+	nfs_sysfs_link_rpc_client(server, server->client, NULL);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
···
 
 	server->nfs_client = clp;
 	nfs_sysfs_add_server(server);
+	nfs_sysfs_link_rpc_client(server, clp->cl_rpcclient, "_state");
 
 	/* Initialise the client representation from the mount data */
 	server->flags = ctx->flags;
···
 	server->fsid = fattr->fsid;
 
 	nfs_sysfs_add_server(server);
+
+	nfs_sysfs_link_rpc_client(server,
+		server->nfs_client->cl_rpcclient, "_state");
 
 	error = nfs_init_server_rpcclient(server,
 			source->client->cl_timeout,

fs/nfs/nfs4client.c

···
 
 	server->nfs_client = clp;
 	nfs_sysfs_add_server(server);
+	nfs_sysfs_link_rpc_client(server, clp->cl_rpcclient, "_state");
 
 	return 0;
 }

fs/nfs/sysfs.c

···
 	}
 }
 
+#define RPC_CLIENT_NAME_SIZE 64
+
+void nfs_sysfs_link_rpc_client(struct nfs_server *server,
+			struct rpc_clnt *clnt, const char *uniq)
+{
+	char name[RPC_CLIENT_NAME_SIZE];
+	int ret;
+
+	strcpy(name, clnt->cl_program->name);
+	strcat(name, uniq ? uniq : "");
+	strcat(name, "_client");
+
+	ret = sysfs_create_link_nowarn(&server->kobj,
+						&clnt->cl_sysfs->kobject, name);
+	if (ret < 0)
+		pr_warn("NFS: can't create link to %s in sysfs (%d)\n",
+			name, ret);
+}
+EXPORT_SYMBOL_GPL(nfs_sysfs_link_rpc_client);
+
 static void nfs_sysfs_sb_release(struct kobject *kobj)
 {
 	/* no-op: why? see lib/kobject.c kobject_cleanup() */

fs/nfs/sysfs.h

···
 void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net);
 void nfs_netns_sysfs_destroy(struct nfs_net *netns);
 
+void nfs_sysfs_link_rpc_client(struct nfs_server *server,
+			struct rpc_clnt *clnt, const char *sysfs_prefix);
 void nfs_sysfs_add_server(struct nfs_server *s);
 void nfs_sysfs_move_server_to_sb(struct super_block *s);
 void nfs_sysfs_move_sb_to_server(struct nfs_server *s);

include/linux/sunrpc/clnt.h

···
 #include <linux/sunrpc/xprtmultipath.h>
 
 struct rpc_inode;
-struct rpc_sysfs_client;
+struct rpc_sysfs_client {
+	struct kobject kobject;
+	struct net *net;
+	struct rpc_clnt *clnt;
+	struct rpc_xprt_switch *xprt_switch;
+};
+
 
 /*
  * The high-level client handle

net/sunrpc/sysfs.h

···
 #ifndef __SUNRPC_SYSFS_H
 #define __SUNRPC_SYSFS_H
 
-struct rpc_sysfs_client {
-	struct kobject kobject;
-	struct net *net;
-	struct rpc_clnt *clnt;
-	struct rpc_xprt_switch *xprt_switch;
-};
-
 struct rpc_sysfs_xprt_switch {
 	struct kobject kobject;
 	struct net *net;