rpcrdma: Merge svcrdma and xprtrdma modules into one

Bi-directional RPC support means code in svcrdma.ko invokes a bit of
code in xprtrdma.ko, and vice versa. To avoid loader/linker loops,
merge the server and client side modules together into a single
module.

When backchannel capabilities are added, the combined module will
register all needed transport capabilities so that Upper Layer
consumers automatically have everything needed to create a
bi-directional transport connection.

Module aliases are added for backwards compatibility with user
space, which still may expect svcrdma.ko or xprtrdma.ko to be
present.

This commit reverts commit 2e8c12e ("xprtrdma: add separate
Kconfig options for NFSoRDMA client and server support") and
provides a single CONFIG option for enabling the new module.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

net/sunrpc/Kconfig

@@ -48,28 +48,16 @@ config SUNRPC_DEBUG
 
 	  If unsure, say Y.
 
-config SUNRPC_XPRT_RDMA_CLIENT
-	tristate "RPC over RDMA Client Support"
+config SUNRPC_XPRT_RDMA
+	tristate "RPC-over-RDMA transport"
 	depends on SUNRPC && INFINIBAND && INFINIBAND_ADDR_TRANS
 	default SUNRPC && INFINIBAND
 	help
-	  This option allows the NFS client to support an RDMA-enabled
-	  transport.
+	  This option allows the NFS client and server to use RDMA
+	  transports (InfiniBand, iWARP, or RoCE).
 
-	  To compile RPC client RDMA transport support as a module,
-	  choose M here: the module will be called xprtrdma.
+	  To compile this support as a module, choose M. The module
+	  will be called rpcrdma.ko.
 
-	  If unsure, say N.
-
-config SUNRPC_XPRT_RDMA_SERVER
-	tristate "RPC over RDMA Server Support"
-	depends on SUNRPC && INFINIBAND && INFINIBAND_ADDR_TRANS
-	default SUNRPC && INFINIBAND
-	help
-	  This option allows the NFS server to support an RDMA-enabled
-	  transport.
-
-	  To compile RPC server RDMA transport support as a module,
-	  choose M here: the module will be called svcrdma.
-
-	  If unsure, say N.
+	  If unsure, or you know there is no RDMA capability on your
+	  hardware platform, say N.

net/sunrpc/Makefile

@@ -5,8 +5,7 @@
 
 obj-$(CONFIG_SUNRPC) += sunrpc.o
 obj-$(CONFIG_SUNRPC_GSS) += auth_gss/
-
-obj-y += xprtrdma/
+obj-$(CONFIG_SUNRPC_XPRT_RDMA) += xprtrdma/
 
 sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \
 	    auth.o auth_null.o auth_unix.o auth_generic.o \

net/sunrpc/xprtrdma/Makefile

@@ -1,9 +1,7 @@
-obj-$(CONFIG_SUNRPC_XPRT_RDMA_CLIENT) += xprtrdma.o
+obj-$(CONFIG_SUNRPC_XPRT_RDMA) += rpcrdma.o
 
-xprtrdma-y := transport.o rpc_rdma.o verbs.o \
-	fmr_ops.o frwr_ops.o physical_ops.o
-
-obj-$(CONFIG_SUNRPC_XPRT_RDMA_SERVER) += svcrdma.o
-
-svcrdma-y := svc_rdma.o svc_rdma_transport.o \
-	svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o
+rpcrdma-y := transport.o rpc_rdma.o verbs.o \
+	fmr_ops.o frwr_ops.o physical_ops.o \
+	svc_rdma.o svc_rdma_transport.o \
+	svc_rdma_marshal.o svc_rdma_sendto.o svc_rdma_recvfrom.o \
+	module.o

net/sunrpc/xprtrdma/module.c

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2015 Oracle.  All rights reserved.
+ */
+
+/* rpcrdma.ko module initialization
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sunrpc/svc_rdma.h>
+#include "xprt_rdma.h"
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_TRANS
+#endif
+
+MODULE_AUTHOR("Open Grid Computing and Network Appliance, Inc.");
+MODULE_DESCRIPTION("RPC/RDMA Transport");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("svcrdma");
+MODULE_ALIAS("xprtrdma");
+
+static void __exit rpc_rdma_cleanup(void)
+{
+	xprt_rdma_cleanup();
+	svc_rdma_cleanup();
+}
+
+static int __init rpc_rdma_init(void)
+{
+	int rc;
+
+	rc = svc_rdma_init();
+	if (rc)
+		goto out;
+
+	rc = xprt_rdma_init();
+	if (rc)
+		svc_rdma_cleanup();
+
+out:
+	return rc;
+}
+
+module_init(rpc_rdma_init);
+module_exit(rpc_rdma_cleanup);

net/sunrpc/xprtrdma/svc_rdma.c

@@ -38,8 +38,7 @@
  *
  * Author: Tom Tucker <tom@opengridcomputing.com>
  */
-#include <linux/module.h>
-#include <linux/init.h>
+
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/sysctl.h>
@@ -295,8 +294,3 @@ int svc_rdma_init(void)
 	destroy_workqueue(svc_rdma_wq);
 	return -ENOMEM;
 }
-MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
-MODULE_DESCRIPTION("SVC RDMA Transport");
-MODULE_LICENSE("Dual BSD/GPL");
-module_init(svc_rdma_init);
-module_exit(svc_rdma_cleanup);

net/sunrpc/xprtrdma/transport.c

@@ -48,7 +48,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 #include <linux/sunrpc/addr.h>
@@ -59,11 +58,6 @@
 # define RPCDBG_FACILITY	RPCDBG_TRANS
 #endif
 
-MODULE_LICENSE("Dual BSD/GPL");
-
-MODULE_DESCRIPTION("RPC/RDMA Transport for Linux kernel NFS");
-MODULE_AUTHOR("Network Appliance, Inc.");
-
 /*
  * tunables
  */
@@ -711,7 +705,7 @@ static struct xprt_class xprt_rdma = {
 	.setup			= xprt_setup_rdma,
 };
 
-static void __exit xprt_rdma_cleanup(void)
+void xprt_rdma_cleanup(void)
 {
 	int rc;
 
@@ -728,7 +722,7 @@ static void __exit xprt_rdma_cleanup(void)
 			__func__, rc);
 }
 
-static int __init xprt_rdma_init(void)
+int xprt_rdma_init(void)
 {
 	int rc;
 
@@ -753,6 +747,3 @@ static int __init xprt_rdma_init(void)
 #endif
 	return 0;
 }
-
-module_init(xprt_rdma_init);
-module_exit(xprt_rdma_cleanup);

net/sunrpc/xprtrdma/xprt_rdma.h

@@ -480,6 +480,11 @@ void rpcrdma_reply_handler(struct rpcrdma_rep *);
  */
 int rpcrdma_marshal_req(struct rpc_rqst *);
 
+/* RPC/RDMA module init - xprtrdma/transport.c
+ */
+int xprt_rdma_init(void);
+void xprt_rdma_cleanup(void);
+
 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 extern struct kmem_cache *svc_rdma_map_cachep;
 /* WR context cache. Created in svc_rdma.c  */