RPCRDMA: rpc rdma transport switch (f58851e6) · Commits · 戴 / test

include/linux/sunrpc/debug.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -88,6 +88,11 @@ enum {
		CTL_SLOTTABLE_TCP,
		CTL_MIN_RESVPORT,
		CTL_MAX_RESVPORT,
		CTL_SLOTTABLE_RDMA,
		CTL_RDMA_MAXINLINEREAD,
		CTL_RDMA_MAXINLINEWRITE,
		CTL_RDMA_WRITEPADDING,
		CTL_RDMA_MEMREG,
		};

		#endif /* _LINUX_SUNRPC_DEBUG_H_ */

net/sunrpc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -5,6 +5,7 @@

		obj-$(CONFIG_SUNRPC) += sunrpc.o
		obj-$(CONFIG_SUNRPC_GSS) += auth_gss/
		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 \

net/sunrpc/xprtrdma/Makefile

0 → 100644

+3 −0

Original line number	Diff line number	Diff line
		obj-$(CONFIG_SUNRPC_XPRT_RDMA) += xprtrdma.o

		xprtrdma-y := transport.o rpc_rdma.o verbs.o

net/sunrpc/xprtrdma/rpc_rdma.c

0 → 100644

+9 −0

Original line number	Diff line number	Diff line
		/*
		* Placeholders for subsequent patches
		*/

		#include "xprt_rdma.h"

		void rpcrdma_conn_func(struct rpcrdma_ep *a) { }
		void rpcrdma_reply_handler(struct rpcrdma_rep *a) { }
		int rpcrdma_marshal_req(struct rpc_rqst *a) { return EINVAL; }

net/sunrpc/xprtrdma/transport.c

0 → 100644

+800 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
		*
		* This software is available to you under a choice of one of two
		* licenses. You may choose to be licensed under the terms of the GNU
		* General Public License (GPL) Version 2, available from the file
		* COPYING in the main directory of this source tree, or the BSD-type
		* license below:
		*
		* Redistribution and use in source and binary forms, with or without
		* modification, are permitted provided that the following conditions
		* are met:
		*
		* Redistributions of source code must retain the above copyright
		* notice, this list of conditions and the following disclaimer.
		*
		* Redistributions in binary form must reproduce the above
		* copyright notice, this list of conditions and the following
		* disclaimer in the documentation and/or other materials provided
		* with the distribution.
		*
		* Neither the name of the Network Appliance, Inc. nor the names of
		* its contributors may be used to endorse or promote products
		* derived from this software without specific prior written
		* permission.
		*
		* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
		* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
		* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
		* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
		* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
		* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
		* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
		* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
		* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
		* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
		* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
		*/

		/*
		* transport.c
		*
		* This file contains the top-level implementation of an RPC RDMA
		* transport.
		*
		* Naming convention: functions beginning with xprt_ are part of the
		* transport switch. All others are RPC RDMA internal.
		*/

		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/seq_file.h>

		#include "xprt_rdma.h"

		#ifdef RPC_DEBUG
		# 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
		*/

		static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
		static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
		static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
		static unsigned int xprt_rdma_inline_write_padding;
		#if !RPCRDMA_PERSISTENT_REGISTRATION
		static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_REGISTER; /* FMR? */
		#else
		static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_ALLPHYSICAL;
		#endif

		#ifdef RPC_DEBUG

		static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
		static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
		static unsigned int zero;
		static unsigned int max_padding = PAGE_SIZE;
		static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
		static unsigned int max_memreg = RPCRDMA_LAST - 1;

		static struct ctl_table_header *sunrpc_table_header;

		static ctl_table xr_tunables_table[] = {
		{
		.ctl_name = CTL_SLOTTABLE_RDMA,
		.procname = "rdma_slot_table_entries",
		.data = &xprt_rdma_slot_table_entries,
		.maxlen = sizeof(unsigned int),
		.mode = 0644,
		.proc_handler = &proc_dointvec_minmax,
		.strategy = &sysctl_intvec,
		.extra1 = &min_slot_table_size,
		.extra2 = &max_slot_table_size
		},
		{
		.ctl_name = CTL_RDMA_MAXINLINEREAD,
		.procname = "rdma_max_inline_read",
		.data = &xprt_rdma_max_inline_read,
		.maxlen = sizeof(unsigned int),
		.mode = 0644,
		.proc_handler = &proc_dointvec,
		.strategy = &sysctl_intvec,
		},
		{
		.ctl_name = CTL_RDMA_MAXINLINEWRITE,
		.procname = "rdma_max_inline_write",
		.data = &xprt_rdma_max_inline_write,
		.maxlen = sizeof(unsigned int),
		.mode = 0644,
		.proc_handler = &proc_dointvec,
		.strategy = &sysctl_intvec,
		},
		{
		.ctl_name = CTL_RDMA_WRITEPADDING,
		.procname = "rdma_inline_write_padding",
		.data = &xprt_rdma_inline_write_padding,
		.maxlen = sizeof(unsigned int),
		.mode = 0644,
		.proc_handler = &proc_dointvec_minmax,
		.strategy = &sysctl_intvec,
		.extra1 = &zero,
		.extra2 = &max_padding,
		},
		{
		.ctl_name = CTL_RDMA_MEMREG,
		.procname = "rdma_memreg_strategy",
		.data = &xprt_rdma_memreg_strategy,
		.maxlen = sizeof(unsigned int),
		.mode = 0644,
		.proc_handler = &proc_dointvec_minmax,
		.strategy = &sysctl_intvec,
		.extra1 = &min_memreg,
		.extra2 = &max_memreg,
		},
		{
		.ctl_name = 0,
		},
		};

		static ctl_table sunrpc_table[] = {
		{
		.ctl_name = CTL_SUNRPC,
		.procname = "sunrpc",
		.mode = 0555,
		.child = xr_tunables_table
		},
		{
		.ctl_name = 0,
		},
		};

		#endif

		static struct rpc_xprt_ops xprt_rdma_procs; /* forward reference */

		static void
		xprt_rdma_format_addresses(struct rpc_xprt *xprt)
		{
		struct sockaddr_in addr = (struct sockaddr_in )
		&rpcx_to_rdmad(xprt).addr;
		char *buf;

		buf = kzalloc(20, GFP_KERNEL);
		if (buf)
		snprintf(buf, 20, NIPQUAD_FMT, NIPQUAD(addr->sin_addr.s_addr));
		xprt->address_strings[RPC_DISPLAY_ADDR] = buf;

		buf = kzalloc(8, GFP_KERNEL);
		if (buf)
		snprintf(buf, 8, "%u", ntohs(addr->sin_port));
		xprt->address_strings[RPC_DISPLAY_PORT] = buf;

		xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";

		buf = kzalloc(48, GFP_KERNEL);
		if (buf)
		snprintf(buf, 48, "addr="NIPQUAD_FMT" port=%u proto=%s",
		NIPQUAD(addr->sin_addr.s_addr),
		ntohs(addr->sin_port), "rdma");
		xprt->address_strings[RPC_DISPLAY_ALL] = buf;

		buf = kzalloc(10, GFP_KERNEL);
		if (buf)
		snprintf(buf, 10, "%02x%02x%02x%02x",
		NIPQUAD(addr->sin_addr.s_addr));
		xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;

		buf = kzalloc(8, GFP_KERNEL);
		if (buf)
		snprintf(buf, 8, "%4hx", ntohs(addr->sin_port));
		xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;

		buf = kzalloc(30, GFP_KERNEL);
		if (buf)
		snprintf(buf, 30, NIPQUAD_FMT".%u.%u",
		NIPQUAD(addr->sin_addr.s_addr),
		ntohs(addr->sin_port) >> 8,
		ntohs(addr->sin_port) & 0xff);
		xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;

		/* netid */
		xprt->address_strings[RPC_DISPLAY_NETID] = "rdma";
		}

		static void
		xprt_rdma_free_addresses(struct rpc_xprt *xprt)
		{
		kfree(xprt->address_strings[RPC_DISPLAY_ADDR]);
		kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
		kfree(xprt->address_strings[RPC_DISPLAY_ALL]);
		kfree(xprt->address_strings[RPC_DISPLAY_HEX_ADDR]);
		kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
		kfree(xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR]);
		}

		static void
		xprt_rdma_connect_worker(struct work_struct *work)
		{
		struct rpcrdma_xprt *r_xprt =
		container_of(work, struct rpcrdma_xprt, rdma_connect.work);
		struct rpc_xprt *xprt = &r_xprt->xprt;
		int rc = 0;

		if (!xprt->shutdown) {
		xprt_clear_connected(xprt);

		dprintk("RPC: %s: %sconnect\n", __func__,
		r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
		rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
		if (rc)
		goto out;
		}
		goto out_clear;

		out:
		xprt_wake_pending_tasks(xprt, rc);

		out_clear:
		dprintk("RPC: %s: exit\n", __func__);
		xprt_clear_connecting(xprt);
		}

		/*
		* xprt_rdma_destroy
		*
		* Destroy the xprt.
		* Free all memory associated with the object, including its own.
		* NOTE: none of the *destroy methods free memory for their top-level
		* objects, even though they may have allocated it (they do free
		* private memory). It's up to the caller to handle it. In this
		* case (RDMA transport), all structure memory is inlined with the
		* struct rpcrdma_xprt.
		*/
		static void
		xprt_rdma_destroy(struct rpc_xprt *xprt)
		{
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
		int rc;

		dprintk("RPC: %s: called\n", __func__);

		cancel_delayed_work(&r_xprt->rdma_connect);
		flush_scheduled_work();

		xprt_clear_connected(xprt);

		rpcrdma_buffer_destroy(&r_xprt->rx_buf);
		rc = rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
		if (rc)
		dprintk("RPC: %s: rpcrdma_ep_destroy returned %i\n",
		__func__, rc);
		rpcrdma_ia_close(&r_xprt->rx_ia);

		xprt_rdma_free_addresses(xprt);

		kfree(xprt->slot);
		xprt->slot = NULL;
		kfree(xprt);

		dprintk("RPC: %s: returning\n", __func__);

		module_put(THIS_MODULE);
		}

		/**
		* xprt_setup_rdma - Set up transport to use RDMA
		*
		* @args: rpc transport arguments
		*/
		static struct rpc_xprt *
		xprt_setup_rdma(struct xprt_create *args)
		{
		struct rpcrdma_create_data_internal cdata;
		struct rpc_xprt *xprt;
		struct rpcrdma_xprt *new_xprt;
		struct rpcrdma_ep *new_ep;
		struct sockaddr_in *sin;
		int rc;

		if (args->addrlen > sizeof(xprt->addr)) {
		dprintk("RPC: %s: address too large\n", __func__);
		return ERR_PTR(-EBADF);
		}

		xprt = kzalloc(sizeof(struct rpcrdma_xprt), GFP_KERNEL);
		if (xprt == NULL) {
		dprintk("RPC: %s: couldn't allocate rpcrdma_xprt\n",
		__func__);
		return ERR_PTR(-ENOMEM);
		}

		xprt->max_reqs = xprt_rdma_slot_table_entries;
		xprt->slot = kcalloc(xprt->max_reqs,
		sizeof(struct rpc_rqst), GFP_KERNEL);
		if (xprt->slot == NULL) {
		kfree(xprt);
		dprintk("RPC: %s: couldn't allocate %d slots\n",
		__func__, xprt->max_reqs);
		return ERR_PTR(-ENOMEM);
		}

		/* 60 second timeout, no retries */
		xprt_set_timeout(&xprt->timeout, 0, 60UL * HZ);
		xprt->bind_timeout = (60U * HZ);
		xprt->connect_timeout = (60U * HZ);
		xprt->reestablish_timeout = (5U * HZ);
		xprt->idle_timeout = (5U * 60 * HZ);

		xprt->resvport = 0; /* privileged port not needed */
		xprt->tsh_size = 0; /* RPC-RDMA handles framing */
		xprt->max_payload = RPCRDMA_MAX_DATA_SEGS * PAGE_SIZE;
		xprt->ops = &xprt_rdma_procs;

		/*
		* Set up RDMA-specific connect data.
		*/

		/* Put server RDMA address in local cdata */
		memcpy(&cdata.addr, args->dstaddr, args->addrlen);

		/* Ensure xprt->addr holds valid server TCP (not RDMA)
		* address, for any side protocols which peek at it */
		xprt->prot = IPPROTO_TCP;
		xprt->addrlen = args->addrlen;
		memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);

		sin = (struct sockaddr_in *)&cdata.addr;
		if (ntohs(sin->sin_port) != 0)
		xprt_set_bound(xprt);

		dprintk("RPC: %s: %u.%u.%u.%u:%u\n", __func__,
		NIPQUAD(sin->sin_addr.s_addr), ntohs(sin->sin_port));

		/* Set max requests */
		cdata.max_requests = xprt->max_reqs;

		/* Set some length limits */
		cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
		cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */

		cdata.inline_wsize = xprt_rdma_max_inline_write;
		if (cdata.inline_wsize > cdata.wsize)
		cdata.inline_wsize = cdata.wsize;

		cdata.inline_rsize = xprt_rdma_max_inline_read;
		if (cdata.inline_rsize > cdata.rsize)
		cdata.inline_rsize = cdata.rsize;

		cdata.padding = xprt_rdma_inline_write_padding;

		/*
		* Create new transport instance, which includes initialized
		* o ia
		* o endpoint
		* o buffers
		*/

		new_xprt = rpcx_to_rdmax(xprt);

		rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
		xprt_rdma_memreg_strategy);
		if (rc)
		goto out1;

		/*
		* initialize and create ep
		*/
		new_xprt->rx_data = cdata;
		new_ep = &new_xprt->rx_ep;
		new_ep->rep_remote_addr = cdata.addr;

		rc = rpcrdma_ep_create(&new_xprt->rx_ep,
		&new_xprt->rx_ia, &new_xprt->rx_data);
		if (rc)
		goto out2;

		/*
		* Allocate pre-registered send and receive buffers for headers and
		* any inline data. Also specify any padding which will be provided
		* from a preregistered zero buffer.
		*/
		rc = rpcrdma_buffer_create(&new_xprt->rx_buf, new_ep, &new_xprt->rx_ia,
		&new_xprt->rx_data);
		if (rc)
		goto out3;

		/*
		* Register a callback for connection events. This is necessary because
		* connection loss notification is async. We also catch connection loss
		* when reaping receives.
		*/
		INIT_DELAYED_WORK(&new_xprt->rdma_connect, xprt_rdma_connect_worker);
		new_ep->rep_func = rpcrdma_conn_func;
		new_ep->rep_xprt = xprt;

		xprt_rdma_format_addresses(xprt);

		if (!try_module_get(THIS_MODULE))
		goto out4;

		return xprt;

		out4:
		xprt_rdma_free_addresses(xprt);
		rc = -EINVAL;
		out3:
		(void) rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
		out2:
		rpcrdma_ia_close(&new_xprt->rx_ia);
		out1:
		kfree(xprt->slot);
		kfree(xprt);
		return ERR_PTR(rc);
		}

		/*
		* Close a connection, during shutdown or timeout/reconnect
		*/
		static void
		xprt_rdma_close(struct rpc_xprt *xprt)
		{
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);

		dprintk("RPC: %s: closing\n", __func__);
		xprt_disconnect(xprt);
		(void) rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
		}

		static void
		xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
		{
		struct sockaddr_in *sap;

		sap = (struct sockaddr_in *)&xprt->addr;
		sap->sin_port = htons(port);
		sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
		sap->sin_port = htons(port);
		dprintk("RPC: %s: %u\n", __func__, port);
		}

		static void
		xprt_rdma_connect(struct rpc_task *task)
		{
		struct rpc_xprt xprt = (struct rpc_xprt )task->tk_xprt;
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);

		if (!xprt_test_and_set_connecting(xprt)) {
		if (r_xprt->rx_ep.rep_connected != 0) {
		/* Reconnect */
		schedule_delayed_work(&r_xprt->rdma_connect,
		xprt->reestablish_timeout);
		} else {
		schedule_delayed_work(&r_xprt->rdma_connect, 0);
		if (!RPC_IS_ASYNC(task))
		flush_scheduled_work();
		}
		}
		}

		static int
		xprt_rdma_reserve_xprt(struct rpc_task *task)
		{
		struct rpc_xprt *xprt = task->tk_xprt;
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
		int credits = atomic_read(&r_xprt->rx_buf.rb_credits);

		/* == RPC_CWNDSCALE @ init, but after setup */
		if (r_xprt->rx_buf.rb_cwndscale == 0UL) {
		r_xprt->rx_buf.rb_cwndscale = xprt->cwnd;
		dprintk("RPC: %s: cwndscale %lu\n", __func__,
		r_xprt->rx_buf.rb_cwndscale);
		BUG_ON(r_xprt->rx_buf.rb_cwndscale <= 0);
		}
		xprt->cwnd = credits * r_xprt->rx_buf.rb_cwndscale;
		return xprt_reserve_xprt_cong(task);
		}

		/*
		* The RDMA allocate/free functions need the task structure as a place
		* to hide the struct rpcrdma_req, which is necessary for the actual send/recv
		* sequence. For this reason, the recv buffers are attached to send
		* buffers for portions of the RPC. Note that the RPC layer allocates
		* both send and receive buffers in the same call. We may register
		* the receive buffer portion when using reply chunks.
		*/
		static void *
		xprt_rdma_allocate(struct rpc_task *task, size_t size)
		{
		struct rpc_xprt *xprt = task->tk_xprt;
		struct rpcrdma_req req, nreq;

		req = rpcrdma_buffer_get(&rpcx_to_rdmax(xprt)->rx_buf);
		BUG_ON(NULL == req);

		if (size > req->rl_size) {
		dprintk("RPC: %s: size %zd too large for buffer[%zd]: "
		"prog %d vers %d proc %d\n",
		__func__, size, req->rl_size,
		task->tk_client->cl_prog, task->tk_client->cl_vers,
		task->tk_msg.rpc_proc->p_proc);
		/*
		* Outgoing length shortage. Our inline write max must have
		* been configured to perform direct i/o.
		*
		* This is therefore a large metadata operation, and the
		* allocate call was made on the maximum possible message,
		* e.g. containing long filename(s) or symlink data. In
		* fact, while these metadata operations might carry
		* large outgoing payloads, they rarely do. However, we
		* have to commit to the request here, so reallocate and
		* register it now. The data path will never require this
		* reallocation.
		*
		* If the allocation or registration fails, the RPC framework
		* will (doggedly) retry.
		*/
		if (rpcx_to_rdmax(xprt)->rx_ia.ri_memreg_strategy ==
		RPCRDMA_BOUNCEBUFFERS) {
		/* forced to "pure inline" */
		dprintk("RPC: %s: too much data (%zd) for inline "
		"(r/w max %d/%d)\n", __func__, size,
		rpcx_to_rdmad(xprt).inline_rsize,
		rpcx_to_rdmad(xprt).inline_wsize);
		size = req->rl_size;
		rpc_exit(task, -EIO); /* fail the operation */
		rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
		goto out;
		}
		if (task->tk_flags & RPC_TASK_SWAPPER)
		nreq = kmalloc(sizeof *req + size, GFP_ATOMIC);
		else
		nreq = kmalloc(sizeof *req + size, GFP_NOFS);
		if (nreq == NULL)
		goto outfail;

		if (rpcrdma_register_internal(&rpcx_to_rdmax(xprt)->rx_ia,
		nreq->rl_base, size + sizeof(struct rpcrdma_req)
		- offsetof(struct rpcrdma_req, rl_base),
		&nreq->rl_handle, &nreq->rl_iov)) {
		kfree(nreq);
		goto outfail;
		}
		rpcx_to_rdmax(xprt)->rx_stats.hardway_register_count += size;
		nreq->rl_size = size;
		nreq->rl_niovs = 0;
		nreq->rl_nchunks = 0;
		nreq->rl_buffer = (struct rpcrdma_buffer *)req;
		nreq->rl_reply = req->rl_reply;
		memcpy(nreq->rl_segments,
		req->rl_segments, sizeof nreq->rl_segments);
		/* flag the swap with an unused field */
		nreq->rl_iov.length = 0;
		req->rl_reply = NULL;
		req = nreq;
		}
		dprintk("RPC: %s: size %zd, request 0x%p\n", __func__, size, req);
		out:
		return req->rl_xdr_buf;

		outfail:
		rpcrdma_buffer_put(req);
		rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
		return NULL;
		}

		/*
		* This function returns all RDMA resources to the pool.
		*/
		static void
		xprt_rdma_free(void *buffer)
		{
		struct rpcrdma_req *req;
		struct rpcrdma_xprt *r_xprt;
		struct rpcrdma_rep *rep;
		int i;

		if (buffer == NULL)
		return;

		req = container_of(buffer, struct rpcrdma_req, rl_xdr_buf[0]);
		r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
		rep = req->rl_reply;

		dprintk("RPC: %s: called on 0x%p%s\n",
		__func__, rep, (rep && rep->rr_func) ? " (with waiter)" : "");

		/*
		* Finish the deregistration. When using mw bind, this was
		* begun in rpcrdma_reply_handler(). In all other modes, we
		* do it here, in thread context. The process is considered
		* complete when the rr_func vector becomes NULL - this
		* was put in place during rpcrdma_reply_handler() - the wait
		* call below will not block if the dereg is "done". If
		* interrupted, our framework will clean up.
		*/
		for (i = 0; req->rl_nchunks;) {
		--req->rl_nchunks;
		i += rpcrdma_deregister_external(
		&req->rl_segments[i], r_xprt, NULL);
		}

		if (rep && wait_event_interruptible(rep->rr_unbind, !rep->rr_func)) {
		rep->rr_func = NULL; /* abandon the callback */
		req->rl_reply = NULL;
		}

		if (req->rl_iov.length == 0) { /* see allocate above */
		struct rpcrdma_req oreq = (struct rpcrdma_req )req->rl_buffer;
		oreq->rl_reply = req->rl_reply;
		(void) rpcrdma_deregister_internal(&r_xprt->rx_ia,
		req->rl_handle,
		&req->rl_iov);
		kfree(req);
		req = oreq;
		}

		/* Put back request+reply buffers */
		rpcrdma_buffer_put(req);
		}

		/*
		* send_request invokes the meat of RPC RDMA. It must do the following:
		* 1. Marshal the RPC request into an RPC RDMA request, which means
		* putting a header in front of data, and creating IOVs for RDMA
		* from those in the request.
		* 2. In marshaling, detect opportunities for RDMA, and use them.
		* 3. Post a recv message to set up asynch completion, then send
		* the request (rpcrdma_ep_post).
		* 4. No partial sends are possible in the RPC-RDMA protocol (as in UDP).
		*/

		static int
		xprt_rdma_send_request(struct rpc_task *task)
		{
		struct rpc_rqst *rqst = task->tk_rqstp;
		struct rpc_xprt *xprt = task->tk_xprt;
		struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);

		/* marshal the send itself */
		if (req->rl_niovs == 0 && rpcrdma_marshal_req(rqst) != 0) {
		r_xprt->rx_stats.failed_marshal_count++;
		dprintk("RPC: %s: rpcrdma_marshal_req failed\n",
		__func__);
		return -EIO;
		}

		if (req->rl_reply == NULL) /* e.g. reconnection */
		rpcrdma_recv_buffer_get(req);

		if (req->rl_reply) {
		req->rl_reply->rr_func = rpcrdma_reply_handler;
		/* this need only be done once, but... */
		req->rl_reply->rr_xprt = xprt;
		}

		if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req)) {
		xprt_disconnect(xprt);
		return -ENOTCONN; /* implies disconnect */
		}

		rqst->rq_bytes_sent = 0;
		return 0;
		}

		static void xprt_rdma_print_stats(struct rpc_xprt xprt, struct seq_file seq)
		{
		struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
		long idle_time = 0;

		if (xprt_connected(xprt))
		idle_time = (long)(jiffies - xprt->last_used) / HZ;

		seq_printf(seq,
		"\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
		"%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",

		0, /* need a local port? */
		xprt->stat.bind_count,
		xprt->stat.connect_count,
		xprt->stat.connect_time,
		idle_time,
		xprt->stat.sends,
		xprt->stat.recvs,
		xprt->stat.bad_xids,
		xprt->stat.req_u,
		xprt->stat.bklog_u,

		r_xprt->rx_stats.read_chunk_count,
		r_xprt->rx_stats.write_chunk_count,
		r_xprt->rx_stats.reply_chunk_count,
		r_xprt->rx_stats.total_rdma_request,
		r_xprt->rx_stats.total_rdma_reply,
		r_xprt->rx_stats.pullup_copy_count,
		r_xprt->rx_stats.fixup_copy_count,
		r_xprt->rx_stats.hardway_register_count,
		r_xprt->rx_stats.failed_marshal_count,
		r_xprt->rx_stats.bad_reply_count);
		}

		/*
		* Plumbing for rpc transport switch and kernel module
		*/

		static struct rpc_xprt_ops xprt_rdma_procs = {
		.reserve_xprt = xprt_rdma_reserve_xprt,
		.release_xprt = xprt_release_xprt_cong, /* sunrpc/xprt.c */
		.release_request = xprt_release_rqst_cong, /* ditto */
		.set_retrans_timeout = xprt_set_retrans_timeout_def, /* ditto */
		.rpcbind = rpcb_getport_async, /* sunrpc/rpcb_clnt.c */
		.set_port = xprt_rdma_set_port,
		.connect = xprt_rdma_connect,
		.buf_alloc = xprt_rdma_allocate,
		.buf_free = xprt_rdma_free,
		.send_request = xprt_rdma_send_request,
		.close = xprt_rdma_close,
		.destroy = xprt_rdma_destroy,
		.print_stats = xprt_rdma_print_stats
		};

		static struct xprt_class xprt_rdma = {
		.list = LIST_HEAD_INIT(xprt_rdma.list),
		.name = "rdma",
		.owner = THIS_MODULE,
		.ident = XPRT_TRANSPORT_RDMA,
		.setup = xprt_setup_rdma,
		};

		static void __exit xprt_rdma_cleanup(void)
		{
		int rc;

		dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
		#ifdef RPC_DEBUG
		if (sunrpc_table_header) {
		unregister_sysctl_table(sunrpc_table_header);
		sunrpc_table_header = NULL;
		}
		#endif
		rc = xprt_unregister_transport(&xprt_rdma);
		if (rc)
		dprintk("RPC: %s: xprt_unregister returned %i\n",
		__func__, rc);
		}

		static int __init xprt_rdma_init(void)
		{
		int rc;

		rc = xprt_register_transport(&xprt_rdma);

		if (rc)
		return rc;

		dprintk(KERN_INFO "RPCRDMA Module Init, register RPC RDMA transport\n");

		dprintk(KERN_INFO "Defaults:\n");
		dprintk(KERN_INFO "\tSlots %d\n"
		"\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
		xprt_rdma_slot_table_entries,
		xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
		dprintk(KERN_INFO "\tPadding %d\n\tMemreg %d\n",
		xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);

		#ifdef RPC_DEBUG
		if (!sunrpc_table_header)
		sunrpc_table_header = register_sysctl_table(sunrpc_table);
		#endif
		return 0;
		}

		module_init(xprt_rdma_init);
		module_exit(xprt_rdma_cleanup);

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