verbs.c 35.0 KB
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/*
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 * 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.
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 */

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/*
 * verbs.c
 *
 * Encapsulates the major functions managing:
 *  o adapters
 *  o endpoints
 *  o connections
 *  o buffer memory
 */

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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/prefetch.h>
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#include <linux/sunrpc/addr.h>
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#include <linux/sunrpc/svc_rdma.h>
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#include <asm/bitops.h>
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#include <linux/module.h> /* try_module_get()/module_put() */
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#include "xprt_rdma.h"

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/*
 * Globals/Macros
 */

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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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# define RPCDBG_FACILITY	RPCDBG_TRANS
#endif

/*
 * internal functions
 */

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static struct workqueue_struct *rpcrdma_receive_wq;
73

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int
rpcrdma_alloc_wq(void)
76
{
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	struct workqueue_struct *recv_wq;
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	recv_wq = alloc_workqueue("xprtrdma_receive",
				  WQ_MEM_RECLAIM | WQ_UNBOUND | WQ_HIGHPRI,
				  0);
	if (!recv_wq)
		return -ENOMEM;
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85 86
	rpcrdma_receive_wq = recv_wq;
	return 0;
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}

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void
rpcrdma_destroy_wq(void)
91
{
92
	struct workqueue_struct *wq;
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	if (rpcrdma_receive_wq) {
		wq = rpcrdma_receive_wq;
		rpcrdma_receive_wq = NULL;
		destroy_workqueue(wq);
	}
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}

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static void
rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
{
	struct rpcrdma_ep *ep = context;

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	pr_err("RPC:       %s: %s on device %s ep %p\n",
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	       __func__, ib_event_msg(event->event),
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		event->device->name, context);
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	if (ep->rep_connected == 1) {
		ep->rep_connected = -EIO;
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		rpcrdma_conn_func(ep);
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		wake_up_all(&ep->rep_connect_wait);
	}
}

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/**
 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
 * @cq:	completion queue (ignored)
 * @wc:	completed WR
 *
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 */
static void
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rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
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{
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	/* WARNING: Only wr_cqe and status are reliable at this point */
	if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
		pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
		       ib_wc_status_msg(wc->status),
		       wc->status, wc->vendor_err);
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}
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static void
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rpcrdma_receive_worker(struct work_struct *work)
{
	struct rpcrdma_rep *rep =
			container_of(work, struct rpcrdma_rep, rr_work);
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	rpcrdma_reply_handler(rep);
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}

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/* Perform basic sanity checking to avoid using garbage
 * to update the credit grant value.
 */
static void
rpcrdma_update_granted_credits(struct rpcrdma_rep *rep)
{
	struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf);
	struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf;
	u32 credits;

	if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
		return;

	credits = be32_to_cpu(rmsgp->rm_credit);
	if (credits == 0)
		credits = 1;	/* don't deadlock */
	else if (credits > buffer->rb_max_requests)
		credits = buffer->rb_max_requests;

	atomic_set(&buffer->rb_credits, credits);
}

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/**
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 * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
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 * @cq:	completion queue (ignored)
 * @wc:	completed WR
 *
 */
169
static void
170
rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
171
{
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	struct ib_cqe *cqe = wc->wr_cqe;
	struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
					       rr_cqe);
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	/* WARNING: Only wr_id and status are reliable at this point */
	if (wc->status != IB_WC_SUCCESS)
		goto out_fail;
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	/* status == SUCCESS means all fields in wc are trustworthy */
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	if (wc->opcode != IB_WC_RECV)
		return;

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	dprintk("RPC:       %s: rep %p opcode 'recv', length %u: success\n",
		__func__, rep, wc->byte_len);

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	rep->rr_len = wc->byte_len;
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	rep->rr_wc_flags = wc->wc_flags;
	rep->rr_inv_rkey = wc->ex.invalidate_rkey;

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	ib_dma_sync_single_for_cpu(rep->rr_device,
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				   rdmab_addr(rep->rr_rdmabuf),
				   rep->rr_len, DMA_FROM_DEVICE);
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	rpcrdma_update_granted_credits(rep);
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out_schedule:
198
	queue_work(rpcrdma_receive_wq, &rep->rr_work);
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	return;
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201 202
out_fail:
	if (wc->status != IB_WC_WR_FLUSH_ERR)
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		pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
		       ib_wc_status_msg(wc->status),
		       wc->status, wc->vendor_err);
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	rep->rr_len = RPCRDMA_BAD_LEN;
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	goto out_schedule;
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}

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static void
rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
			       struct rdma_conn_param *param)
{
	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
	const struct rpcrdma_connect_private *pmsg = param->private_data;
	unsigned int rsize, wsize;

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	/* Default settings for RPC-over-RDMA Version One */
	r_xprt->rx_ia.ri_reminv_expected = false;
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	rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
	wsize = RPCRDMA_V1_DEF_INLINE_SIZE;

	if (pmsg &&
	    pmsg->cp_magic == rpcrdma_cmp_magic &&
	    pmsg->cp_version == RPCRDMA_CMP_VERSION) {
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		r_xprt->rx_ia.ri_reminv_expected = true;
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		rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
		wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
	}

	if (rsize < cdata->inline_rsize)
		cdata->inline_rsize = rsize;
	if (wsize < cdata->inline_wsize)
		cdata->inline_wsize = wsize;
	pr_info("rpcrdma: max send %u, max recv %u\n",
		cdata->inline_wsize, cdata->inline_rsize);
	rpcrdma_set_max_header_sizes(r_xprt);
}

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static int
rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
{
	struct rpcrdma_xprt *xprt = id->context;
	struct rpcrdma_ia *ia = &xprt->rx_ia;
	struct rpcrdma_ep *ep = &xprt->rx_ep;
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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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	struct sockaddr *sap = (struct sockaddr *)&ep->rep_remote_addr;
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#endif
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	struct ib_qp_attr *attr = &ia->ri_qp_attr;
	struct ib_qp_init_attr *iattr = &ia->ri_qp_init_attr;
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	int connstate = 0;

	switch (event->event) {
	case RDMA_CM_EVENT_ADDR_RESOLVED:
	case RDMA_CM_EVENT_ROUTE_RESOLVED:
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		ia->ri_async_rc = 0;
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		complete(&ia->ri_done);
		break;
	case RDMA_CM_EVENT_ADDR_ERROR:
		ia->ri_async_rc = -EHOSTUNREACH;
		dprintk("RPC:       %s: CM address resolution error, ep 0x%p\n",
			__func__, ep);
		complete(&ia->ri_done);
		break;
	case RDMA_CM_EVENT_ROUTE_ERROR:
		ia->ri_async_rc = -ENETUNREACH;
		dprintk("RPC:       %s: CM route resolution error, ep 0x%p\n",
			__func__, ep);
		complete(&ia->ri_done);
		break;
	case RDMA_CM_EVENT_ESTABLISHED:
		connstate = 1;
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		ib_query_qp(ia->ri_id->qp, attr,
			    IB_QP_MAX_QP_RD_ATOMIC | IB_QP_MAX_DEST_RD_ATOMIC,
			    iattr);
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		dprintk("RPC:       %s: %d responder resources"
			" (%d initiator)\n",
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			__func__, attr->max_dest_rd_atomic,
			attr->max_rd_atomic);
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		rpcrdma_update_connect_private(xprt, &event->param.conn);
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		goto connected;
	case RDMA_CM_EVENT_CONNECT_ERROR:
		connstate = -ENOTCONN;
		goto connected;
	case RDMA_CM_EVENT_UNREACHABLE:
		connstate = -ENETDOWN;
		goto connected;
	case RDMA_CM_EVENT_REJECTED:
		connstate = -ECONNREFUSED;
		goto connected;
	case RDMA_CM_EVENT_DISCONNECTED:
		connstate = -ECONNABORTED;
		goto connected;
	case RDMA_CM_EVENT_DEVICE_REMOVAL:
		connstate = -ENODEV;
connected:
		dprintk("RPC:       %s: %sconnected\n",
					__func__, connstate > 0 ? "" : "dis");
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		atomic_set(&xprt->rx_buf.rb_credits, 1);
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		ep->rep_connected = connstate;
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		rpcrdma_conn_func(ep);
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		wake_up_all(&ep->rep_connect_wait);
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		/*FALLTHROUGH*/
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	default:
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		dprintk("RPC:       %s: %pIS:%u (ep 0x%p): %s\n",
			__func__, sap, rpc_get_port(sap), ep,
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			rdma_event_msg(event->event));
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		break;
	}

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#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
312
	if (connstate == 1) {
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		int ird = attr->max_dest_rd_atomic;
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		int tird = ep->rep_remote_cma.responder_resources;
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		pr_info("rpcrdma: connection to %pIS:%u on %s, memreg '%s', %d credits, %d responders%s\n",
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			sap, rpc_get_port(sap),
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			ia->ri_device->name,
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			ia->ri_ops->ro_displayname,
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			xprt->rx_buf.rb_max_requests,
			ird, ird < 4 && ird < tird / 2 ? " (low!)" : "");
	} else if (connstate < 0) {
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		pr_info("rpcrdma: connection to %pIS:%u closed (%d)\n",
			sap, rpc_get_port(sap), connstate);
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	}
#endif

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	return 0;
}

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static void rpcrdma_destroy_id(struct rdma_cm_id *id)
{
	if (id) {
		module_put(id->device->owner);
		rdma_destroy_id(id);
	}
}

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static struct rdma_cm_id *
rpcrdma_create_id(struct rpcrdma_xprt *xprt,
			struct rpcrdma_ia *ia, struct sockaddr *addr)
{
	struct rdma_cm_id *id;
	int rc;

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	init_completion(&ia->ri_done);

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	id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
			    IB_QPT_RC);
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	if (IS_ERR(id)) {
		rc = PTR_ERR(id);
		dprintk("RPC:       %s: rdma_create_id() failed %i\n",
			__func__, rc);
		return id;
	}

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	ia->ri_async_rc = -ETIMEDOUT;
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	rc = rdma_resolve_addr(id, NULL, addr, RDMA_RESOLVE_TIMEOUT);
	if (rc) {
		dprintk("RPC:       %s: rdma_resolve_addr() failed %i\n",
			__func__, rc);
		goto out;
	}
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	wait_for_completion_interruptible_timeout(&ia->ri_done,
				msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
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	/* FIXME:
	 * Until xprtrdma supports DEVICE_REMOVAL, the provider must
	 * be pinned while there are active NFS/RDMA mounts to prevent
	 * hangs and crashes at umount time.
	 */
	if (!ia->ri_async_rc && !try_module_get(id->device->owner)) {
		dprintk("RPC:       %s: Failed to get device module\n",
			__func__);
		ia->ri_async_rc = -ENODEV;
	}
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	rc = ia->ri_async_rc;
	if (rc)
		goto out;

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	ia->ri_async_rc = -ETIMEDOUT;
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	rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
	if (rc) {
		dprintk("RPC:       %s: rdma_resolve_route() failed %i\n",
			__func__, rc);
386
		goto put;
387
	}
388 389
	wait_for_completion_interruptible_timeout(&ia->ri_done,
				msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
390 391
	rc = ia->ri_async_rc;
	if (rc)
392
		goto put;
393 394

	return id;
395 396
put:
	module_put(id->device->owner);
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out:
	rdma_destroy_id(id);
	return ERR_PTR(rc);
}

/*
 * Exported functions.
 */

/*
 * Open and initialize an Interface Adapter.
 *  o initializes fields of struct rpcrdma_ia, including
 *    interface and provider attributes and protection zone.
 */
int
rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
{
	struct rpcrdma_ia *ia = &xprt->rx_ia;
415 416
	int rc;

417 418 419 420 421
	ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
	if (IS_ERR(ia->ri_id)) {
		rc = PTR_ERR(ia->ri_id);
		goto out1;
	}
422
	ia->ri_device = ia->ri_id->device;
423

424
	ia->ri_pd = ib_alloc_pd(ia->ri_device);
425 426
	if (IS_ERR(ia->ri_pd)) {
		rc = PTR_ERR(ia->ri_pd);
427
		pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
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		goto out2;
	}

431
	switch (memreg) {
432
	case RPCRDMA_FRMR:
433 434 435 436 437
		if (frwr_is_supported(ia)) {
			ia->ri_ops = &rpcrdma_frwr_memreg_ops;
			break;
		}
		/*FALLTHROUGH*/
438
	case RPCRDMA_MTHCAFMR:
439 440 441 442 443
		if (fmr_is_supported(ia)) {
			ia->ri_ops = &rpcrdma_fmr_memreg_ops;
			break;
		}
		/*FALLTHROUGH*/
444
	default:
445 446 447
		pr_err("rpcrdma: Unsupported memory registration mode: %d\n",
		       memreg);
		rc = -EINVAL;
448
		goto out3;
449 450 451
	}

	return 0;
452 453 454 455

out3:
	ib_dealloc_pd(ia->ri_pd);
	ia->ri_pd = NULL;
456
out2:
457
	rpcrdma_destroy_id(ia->ri_id);
458
	ia->ri_id = NULL;
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out1:
	return rc;
}

/*
 * Clean up/close an IA.
 *   o if event handles and PD have been initialized, free them.
 *   o close the IA
 */
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
	dprintk("RPC:       %s: entering\n", __func__);
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	if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
		if (ia->ri_id->qp)
			rdma_destroy_qp(ia->ri_id);
475
		rpcrdma_destroy_id(ia->ri_id);
476 477
		ia->ri_id = NULL;
	}
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	/* If the pd is still busy, xprtrdma missed freeing a resource */
	if (ia->ri_pd && !IS_ERR(ia->ri_pd))
481
		ib_dealloc_pd(ia->ri_pd);
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}

/*
 * Create unconnected endpoint.
 */
int
rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
				struct rpcrdma_create_data_internal *cdata)
{
491
	struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
492
	struct ib_cq *sendcq, *recvcq;
493
	unsigned int max_qp_wr;
494
	int rc;
495

496
	if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_SEND_SGES) {
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		dprintk("RPC:       %s: insufficient sge's available\n",
			__func__);
		return -ENOMEM;
	}

502
	if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
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		dprintk("RPC:       %s: insufficient wqe's available\n",
			__func__);
		return -ENOMEM;
	}
507
	max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS - 1;
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509
	/* check provider's send/recv wr limits */
510 511
	if (cdata->max_requests > max_qp_wr)
		cdata->max_requests = max_qp_wr;
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	ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
	ep->rep_attr.qp_context = ep;
	ep->rep_attr.srq = NULL;
	ep->rep_attr.cap.max_send_wr = cdata->max_requests;
517
	ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
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	ep->rep_attr.cap.max_send_wr += 1;	/* drain cqe */
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	rc = ia->ri_ops->ro_open(ia, ep, cdata);
	if (rc)
		return rc;
522
	ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
523
	ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
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	ep->rep_attr.cap.max_recv_wr += 1;	/* drain cqe */
525
	ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_SEND_SGES;
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	ep->rep_attr.cap.max_recv_sge = 1;
	ep->rep_attr.cap.max_inline_data = 0;
	ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
	ep->rep_attr.qp_type = IB_QPT_RC;
	ep->rep_attr.port_num = ~0;

	dprintk("RPC:       %s: requested max: dtos: send %d recv %d; "
		"iovs: send %d recv %d\n",
		__func__,
		ep->rep_attr.cap.max_send_wr,
		ep->rep_attr.cap.max_recv_wr,
		ep->rep_attr.cap.max_send_sge,
		ep->rep_attr.cap.max_recv_sge);

	/* set trigger for requesting send completion */
541
	ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
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	if (ep->rep_cqinit <= 2)
		ep->rep_cqinit = 0;	/* always signal? */
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	INIT_CQCOUNT(ep);
	init_waitqueue_head(&ep->rep_connect_wait);
546
	INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
547

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	sendcq = ib_alloc_cq(ia->ri_device, NULL,
			     ep->rep_attr.cap.max_send_wr + 1,
			     0, IB_POLL_SOFTIRQ);
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	if (IS_ERR(sendcq)) {
		rc = PTR_ERR(sendcq);
		dprintk("RPC:       %s: failed to create send CQ: %i\n",
554 555 556 557
			__func__, rc);
		goto out1;
	}

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	recvcq = ib_alloc_cq(ia->ri_device, NULL,
			     ep->rep_attr.cap.max_recv_wr + 1,
			     0, IB_POLL_SOFTIRQ);
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	if (IS_ERR(recvcq)) {
		rc = PTR_ERR(recvcq);
		dprintk("RPC:       %s: failed to create recv CQ: %i\n",
			__func__, rc);
		goto out2;
	}

	ep->rep_attr.send_cq = sendcq;
	ep->rep_attr.recv_cq = recvcq;
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	/* Initialize cma parameters */
572
	memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
573

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	/* Prepare RDMA-CM private message */
	pmsg->cp_magic = rpcrdma_cmp_magic;
	pmsg->cp_version = RPCRDMA_CMP_VERSION;
577
	pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
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	pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);
	pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);
	ep->rep_remote_cma.private_data = pmsg;
	ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
582 583

	/* Client offers RDMA Read but does not initiate */
584
	ep->rep_remote_cma.initiator_depth = 0;
585
	if (ia->ri_device->attrs.max_qp_rd_atom > 32)	/* arbitrary but <= 255 */
586 587
		ep->rep_remote_cma.responder_resources = 32;
	else
588
		ep->rep_remote_cma.responder_resources =
589
						ia->ri_device->attrs.max_qp_rd_atom;
590

591 592 593 594 595 596 597 598 599 600
	/* Limit transport retries so client can detect server
	 * GID changes quickly. RPC layer handles re-establishing
	 * transport connection and retransmission.
	 */
	ep->rep_remote_cma.retry_count = 6;

	/* RPC-over-RDMA handles its own flow control. In addition,
	 * make all RNR NAKs visible so we know that RPC-over-RDMA
	 * flow control is working correctly (no NAKs should be seen).
	 */
601 602 603 604 605 606
	ep->rep_remote_cma.flow_control = 0;
	ep->rep_remote_cma.rnr_retry_count = 0;

	return 0;

out2:
607
	ib_free_cq(sendcq);
608 609 610 611 612 613 614 615 616 617 618
out1:
	return rc;
}

/*
 * rpcrdma_ep_destroy
 *
 * Disconnect and destroy endpoint. After this, the only
 * valid operations on the ep are to free it (if dynamically
 * allocated) or re-create it.
 */
619
void
620 621 622 623 624
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
	dprintk("RPC:       %s: entering, connected is %d\n",
		__func__, ep->rep_connected);

625 626
	cancel_delayed_work_sync(&ep->rep_connect_worker);

627
	if (ia->ri_id->qp) {
628
		rpcrdma_ep_disconnect(ep, ia);
629 630
		rdma_destroy_qp(ia->ri_id);
		ia->ri_id->qp = NULL;
631 632
	}

633
	ib_free_cq(ep->rep_attr.recv_cq);
634
	ib_free_cq(ep->rep_attr.send_cq);
635 636 637 638 639 640 641 642
}

/*
 * Connect unconnected endpoint.
 */
int
rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
643
	struct rdma_cm_id *id, *old;
644 645 646
	int rc = 0;
	int retry_count = 0;

647
	if (ep->rep_connected != 0) {
648 649
		struct rpcrdma_xprt *xprt;
retry:
650
		dprintk("RPC:       %s: reconnecting...\n", __func__);
651 652

		rpcrdma_ep_disconnect(ep, ia);
653 654 655 656 657

		xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
		id = rpcrdma_create_id(xprt, ia,
				(struct sockaddr *)&xprt->rx_data.addr);
		if (IS_ERR(id)) {
658
			rc = -EHOSTUNREACH;
659 660 661 662 663 664 665 666 667
			goto out;
		}
		/* TEMP TEMP TEMP - fail if new device:
		 * Deregister/remarshal *all* requests!
		 * Close and recreate adapter, pd, etc!
		 * Re-determine all attributes still sane!
		 * More stuff I haven't thought of!
		 * Rrrgh!
		 */
668
		if (ia->ri_device != id->device) {
669 670
			printk("RPC:       %s: can't reconnect on "
				"different device!\n", __func__);
671
			rpcrdma_destroy_id(id);
672
			rc = -ENETUNREACH;
673 674 675
			goto out;
		}
		/* END TEMP */
676 677 678 679
		rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
		if (rc) {
			dprintk("RPC:       %s: rdma_create_qp failed %i\n",
				__func__, rc);
680
			rpcrdma_destroy_id(id);
681 682 683
			rc = -ENETUNREACH;
			goto out;
		}
684 685

		old = ia->ri_id;
686
		ia->ri_id = id;
687 688

		rdma_destroy_qp(old);
689
		rpcrdma_destroy_id(old);
690 691 692 693 694 695 696 697 698
	} else {
		dprintk("RPC:       %s: connecting...\n", __func__);
		rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
		if (rc) {
			dprintk("RPC:       %s: rdma_create_qp failed %i\n",
				__func__, rc);
			/* do not update ep->rep_connected */
			return -ENETUNREACH;
		}
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717
	}

	ep->rep_connected = 0;

	rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
	if (rc) {
		dprintk("RPC:       %s: rdma_connect() failed with %i\n",
				__func__, rc);
		goto out;
	}

	wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);

	/*
	 * Check state. A non-peer reject indicates no listener
	 * (ECONNREFUSED), which may be a transient state. All
	 * others indicate a transport condition which has already
	 * undergone a best-effort.
	 */
718 719
	if (ep->rep_connected == -ECONNREFUSED &&
	    ++retry_count <= RDMA_CONNECT_RETRY_MAX) {
720 721 722 723 724 725
		dprintk("RPC:       %s: non-peer_reject, retry\n", __func__);
		goto retry;
	}
	if (ep->rep_connected <= 0) {
		/* Sometimes, the only way to reliably connect to remote
		 * CMs is to use same nonzero values for ORD and IRD. */
726 727 728 729 730 731 732 733
		if (retry_count++ <= RDMA_CONNECT_RETRY_MAX + 1 &&
		    (ep->rep_remote_cma.responder_resources == 0 ||
		     ep->rep_remote_cma.initiator_depth !=
				ep->rep_remote_cma.responder_resources)) {
			if (ep->rep_remote_cma.responder_resources == 0)
				ep->rep_remote_cma.responder_resources = 1;
			ep->rep_remote_cma.initiator_depth =
				ep->rep_remote_cma.responder_resources;
734
			goto retry;
735
		}
736 737
		rc = ep->rep_connected;
	} else {
738 739 740
		struct rpcrdma_xprt *r_xprt;
		unsigned int extras;

741
		dprintk("RPC:       %s: connected\n", __func__);
742 743 744 745 746 747

		r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
		extras = r_xprt->rx_buf.rb_bc_srv_max_requests;

		if (extras) {
			rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
748
			if (rc) {
749 750 751
				pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
					__func__, rc);
				rc = 0;
752
			}
753
		}
754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770
	}

out:
	if (rc)
		ep->rep_connected = rc;
	return rc;
}

/*
 * rpcrdma_ep_disconnect
 *
 * This is separate from destroy to facilitate the ability
 * to reconnect without recreating the endpoint.
 *
 * This call is not reentrant, and must not be made in parallel
 * on the same endpoint.
 */
771
void
772 773 774 775 776 777 778 779 780 781 782 783 784 785 786
rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
	int rc;

	rc = rdma_disconnect(ia->ri_id);
	if (!rc) {
		/* returns without wait if not connected */
		wait_event_interruptible(ep->rep_connect_wait,
							ep->rep_connected != 1);
		dprintk("RPC:       %s: after wait, %sconnected\n", __func__,
			(ep->rep_connected == 1) ? "still " : "dis");
	} else {
		dprintk("RPC:       %s: rdma_disconnect %i\n", __func__, rc);
		ep->rep_connected = rc;
	}
787 788

	ib_drain_qp(ia->ri_id->qp);
789 790
}

791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808
static void
rpcrdma_mr_recovery_worker(struct work_struct *work)
{
	struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
						  rb_recovery_worker.work);
	struct rpcrdma_mw *mw;

	spin_lock(&buf->rb_recovery_lock);
	while (!list_empty(&buf->rb_stale_mrs)) {
		mw = list_first_entry(&buf->rb_stale_mrs,
				      struct rpcrdma_mw, mw_list);
		list_del_init(&mw->mw_list);
		spin_unlock(&buf->rb_recovery_lock);

		dprintk("RPC:       %s: recovering MR %p\n", __func__, mw);
		mw->mw_xprt->rx_ia.ri_ops->ro_recover_mr(mw);

		spin_lock(&buf->rb_recovery_lock);
809
	}
810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825
	spin_unlock(&buf->rb_recovery_lock);
}

void
rpcrdma_defer_mr_recovery(struct rpcrdma_mw *mw)
{
	struct rpcrdma_xprt *r_xprt = mw->mw_xprt;
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;

	spin_lock(&buf->rb_recovery_lock);
	list_add(&mw->mw_list, &buf->rb_stale_mrs);
	spin_unlock(&buf->rb_recovery_lock);

	schedule_delayed_work(&buf->rb_recovery_worker, 0);
}

C
Chuck Lever 已提交
826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874
static void
rpcrdma_create_mrs(struct rpcrdma_xprt *r_xprt)
{
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
	unsigned int count;
	LIST_HEAD(free);
	LIST_HEAD(all);

	for (count = 0; count < 32; count++) {
		struct rpcrdma_mw *mw;
		int rc;

		mw = kzalloc(sizeof(*mw), GFP_KERNEL);
		if (!mw)
			break;

		rc = ia->ri_ops->ro_init_mr(ia, mw);
		if (rc) {
			kfree(mw);
			break;
		}

		mw->mw_xprt = r_xprt;

		list_add(&mw->mw_list, &free);
		list_add(&mw->mw_all, &all);
	}

	spin_lock(&buf->rb_mwlock);
	list_splice(&free, &buf->rb_mws);
	list_splice(&all, &buf->rb_all);
	r_xprt->rx_stats.mrs_allocated += count;
	spin_unlock(&buf->rb_mwlock);

	dprintk("RPC:       %s: created %u MRs\n", __func__, count);
}

static void
rpcrdma_mr_refresh_worker(struct work_struct *work)
{
	struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
						  rb_refresh_worker.work);
	struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
						   rx_buf);

	rpcrdma_create_mrs(r_xprt);
}

875
struct rpcrdma_req *
876 877
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
878
	struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
879 880
	struct rpcrdma_req *req;

881
	req = kzalloc(sizeof(*req), GFP_KERNEL);
882
	if (req == NULL)
883
		return ERR_PTR(-ENOMEM);
884

885 886 887 888
	INIT_LIST_HEAD(&req->rl_free);
	spin_lock(&buffer->rb_reqslock);
	list_add(&req->rl_all, &buffer->rb_allreqs);
	spin_unlock(&buffer->rb_reqslock);
889
	req->rl_cqe.done = rpcrdma_wc_send;
890
	req->rl_buffer = &r_xprt->rx_buf;
891
	INIT_LIST_HEAD(&req->rl_registered);
892 893
	req->rl_send_wr.next = NULL;
	req->rl_send_wr.wr_cqe = &req->rl_cqe;
894
	req->rl_send_wr.sg_list = req->rl_send_sge;
895
	req->rl_send_wr.opcode = IB_WR_SEND;
896 897 898
	return req;
}

899
struct rpcrdma_rep *
900 901 902 903 904 905 906 907
rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
{
	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
	struct rpcrdma_rep *rep;
	int rc;

	rc = -ENOMEM;
908
	rep = kzalloc(sizeof(*rep), GFP_KERNEL);
909 910 911
	if (rep == NULL)
		goto out;

912
	rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
913
					       DMA_FROM_DEVICE, GFP_KERNEL);
914 915
	if (IS_ERR(rep->rr_rdmabuf)) {
		rc = PTR_ERR(rep->rr_rdmabuf);
916
		goto out_free;
917
	}
918

919
	rep->rr_device = ia->ri_device;
920
	rep->rr_cqe.done = rpcrdma_wc_receive;
921
	rep->rr_rxprt = r_xprt;
922
	INIT_WORK(&rep->rr_work, rpcrdma_receive_worker);
923 924 925 926
	rep->rr_recv_wr.next = NULL;
	rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
	rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
	rep->rr_recv_wr.num_sge = 1;
927 928 929 930 931 932 933 934
	return rep;

out_free:
	kfree(rep);
out:
	return ERR_PTR(rc);
}

935
int
936
rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
937
{
938
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
939 940
	int i, rc;

941
	buf->rb_max_requests = r_xprt->rx_data.max_requests;
942
	buf->rb_bc_srv_max_requests = 0;
943
	atomic_set(&buf->rb_credits, 1);
C
Chuck Lever 已提交
944
	spin_lock_init(&buf->rb_mwlock);
945 946
	spin_lock_init(&buf->rb_lock);
	spin_lock_init(&buf->rb_recovery_lock);
C
Chuck Lever 已提交
947 948
	INIT_LIST_HEAD(&buf->rb_mws);
	INIT_LIST_HEAD(&buf->rb_all);
949
	INIT_LIST_HEAD(&buf->rb_stale_mrs);
C
Chuck Lever 已提交
950 951
	INIT_DELAYED_WORK(&buf->rb_refresh_worker,
			  rpcrdma_mr_refresh_worker);
952 953
	INIT_DELAYED_WORK(&buf->rb_recovery_worker,
			  rpcrdma_mr_recovery_worker);
954

C
Chuck Lever 已提交
955
	rpcrdma_create_mrs(r_xprt);
956

957
	INIT_LIST_HEAD(&buf->rb_send_bufs);
958 959
	INIT_LIST_HEAD(&buf->rb_allreqs);
	spin_lock_init(&buf->rb_reqslock);
960 961 962
	for (i = 0; i < buf->rb_max_requests; i++) {
		struct rpcrdma_req *req;

963 964
		req = rpcrdma_create_req(r_xprt);
		if (IS_ERR(req)) {
965 966
			dprintk("RPC:       %s: request buffer %d alloc"
				" failed\n", __func__, i);
967
			rc = PTR_ERR(req);
968 969
			goto out;
		}
970
		req->rl_backchannel = false;
971 972 973 974
		list_add(&req->rl_free, &buf->rb_send_bufs);
	}

	INIT_LIST_HEAD(&buf->rb_recv_bufs);
975
	for (i = 0; i < buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS; i++) {
976
		struct rpcrdma_rep *rep;
977

978 979
		rep = rpcrdma_create_rep(r_xprt);
		if (IS_ERR(rep)) {
980 981
			dprintk("RPC:       %s: reply buffer %d alloc failed\n",
				__func__, i);
982
			rc = PTR_ERR(rep);
983 984
			goto out;
		}
985
		list_add(&rep->rr_list, &buf->rb_recv_bufs);
986
	}
987

988 989 990 991 992 993
	return 0;
out:
	rpcrdma_buffer_destroy(buf);
	return rc;
}

994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015
static struct rpcrdma_req *
rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
{
	struct rpcrdma_req *req;

	req = list_first_entry(&buf->rb_send_bufs,
			       struct rpcrdma_req, rl_free);
	list_del(&req->rl_free);
	return req;
}

static struct rpcrdma_rep *
rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
{
	struct rpcrdma_rep *rep;

	rep = list_first_entry(&buf->rb_recv_bufs,
			       struct rpcrdma_rep, rr_list);
	list_del(&rep->rr_list);
	return rep;
}

1016
static void
1017
rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
1018
{
1019
	rpcrdma_free_regbuf(rep->rr_rdmabuf);
1020 1021 1022
	kfree(rep);
}

1023
void
1024
rpcrdma_destroy_req(struct rpcrdma_req *req)
1025
{
1026 1027 1028
	rpcrdma_free_regbuf(req->rl_recvbuf);
	rpcrdma_free_regbuf(req->rl_sendbuf);
	rpcrdma_free_regbuf(req->rl_rdmabuf);
1029 1030 1031
	kfree(req);
}

C
Chuck Lever 已提交
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057
static void
rpcrdma_destroy_mrs(struct rpcrdma_buffer *buf)
{
	struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
						   rx_buf);
	struct rpcrdma_ia *ia = rdmab_to_ia(buf);
	struct rpcrdma_mw *mw;
	unsigned int count;

	count = 0;
	spin_lock(&buf->rb_mwlock);
	while (!list_empty(&buf->rb_all)) {
		mw = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
		list_del(&mw->mw_all);

		spin_unlock(&buf->rb_mwlock);
		ia->ri_ops->ro_release_mr(mw);
		count++;
		spin_lock(&buf->rb_mwlock);
	}
	spin_unlock(&buf->rb_mwlock);
	r_xprt->rx_stats.mrs_allocated = 0;

	dprintk("RPC:       %s: released %u MRs\n", __func__, count);
}

1058 1059 1060
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
1061 1062
	cancel_delayed_work_sync(&buf->rb_recovery_worker);

1063 1064
	while (!list_empty(&buf->rb_recv_bufs)) {
		struct rpcrdma_rep *rep;
1065

1066
		rep = rpcrdma_buffer_get_rep_locked(buf);
1067
		rpcrdma_destroy_rep(rep);
1068
	}
1069
	buf->rb_send_count = 0;
1070

1071 1072
	spin_lock(&buf->rb_reqslock);
	while (!list_empty(&buf->rb_allreqs)) {
1073
		struct rpcrdma_req *req;
A
Allen Andrews 已提交
1074

1075 1076 1077 1078 1079
		req = list_first_entry(&buf->rb_allreqs,
				       struct rpcrdma_req, rl_all);
		list_del(&req->rl_all);

		spin_unlock(&buf->rb_reqslock);
1080
		rpcrdma_destroy_req(req);
1081
		spin_lock(&buf->rb_reqslock);
1082
	}
1083
	spin_unlock(&buf->rb_reqslock);
1084
	buf->rb_recv_count = 0;
A
Allen Andrews 已提交
1085

C
Chuck Lever 已提交
1086
	rpcrdma_destroy_mrs(buf);
1087 1088
}

1089 1090
struct rpcrdma_mw *
rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
1091
{
1092 1093 1094
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
	struct rpcrdma_mw *mw = NULL;

C
Chuck Lever 已提交
1095
	spin_lock(&buf->rb_mwlock);
1096 1097 1098 1099
	if (!list_empty(&buf->rb_mws)) {
		mw = list_first_entry(&buf->rb_mws,
				      struct rpcrdma_mw, mw_list);
		list_del_init(&mw->mw_list);
1100
	}
C
Chuck Lever 已提交
1101
	spin_unlock(&buf->rb_mwlock);
1102 1103

	if (!mw)
C
Chuck Lever 已提交
1104
		goto out_nomws;
1105
	return mw;
C
Chuck Lever 已提交
1106 1107 1108 1109 1110 1111 1112 1113 1114

out_nomws:
	dprintk("RPC:       %s: no MWs available\n", __func__);
	schedule_delayed_work(&buf->rb_refresh_worker, 0);

	/* Allow the reply handler and refresh worker to run */
	cond_resched();

	return NULL;
1115 1116
}

1117 1118
void
rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
1119
{
1120
	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1121

C
Chuck Lever 已提交
1122
	spin_lock(&buf->rb_mwlock);
1123
	list_add_tail(&mw->mw_list, &buf->rb_mws);
C
Chuck Lever 已提交
1124
	spin_unlock(&buf->rb_mwlock);
1125 1126
}

1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
static struct rpcrdma_rep *
rpcrdma_buffer_get_rep(struct rpcrdma_buffer *buffers)
{
	/* If an RPC previously completed without a reply (say, a
	 * credential problem or a soft timeout occurs) then hold off
	 * on supplying more Receive buffers until the number of new
	 * pending RPCs catches up to the number of posted Receives.
	 */
	if (unlikely(buffers->rb_send_count < buffers->rb_recv_count))
		return NULL;

	if (unlikely(list_empty(&buffers->rb_recv_bufs)))
		return NULL;
	buffers->rb_recv_count++;
	return rpcrdma_buffer_get_rep_locked(buffers);
}

1144 1145
/*
 * Get a set of request/reply buffers.
1146 1147
 *
 * Reply buffer (if available) is attached to send buffer upon return.
1148 1149 1150 1151 1152
 */
struct rpcrdma_req *
rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
{
	struct rpcrdma_req *req;
1153

1154
	spin_lock(&buffers->rb_lock);
1155 1156
	if (list_empty(&buffers->rb_send_bufs))
		goto out_reqbuf;
1157
	buffers->rb_send_count++;
1158
	req = rpcrdma_buffer_get_req_locked(buffers);
1159
	req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1160
	spin_unlock(&buffers->rb_lock);
1161
	return req;
1162

1163
out_reqbuf:
1164
	spin_unlock(&buffers->rb_lock);
1165
	pr_warn("RPC:       %s: out of request buffers\n", __func__);
1166
	return NULL;
1167 1168 1169 1170 1171 1172 1173 1174 1175 1176
}

/*
 * Put request/reply buffers back into pool.
 * Pre-decrement counter/array index.
 */
void
rpcrdma_buffer_put(struct rpcrdma_req *req)
{
	struct rpcrdma_buffer *buffers = req->rl_buffer;
1177
	struct rpcrdma_rep *rep = req->rl_reply;
1178

1179
	req->rl_send_wr.num_sge = 0;
1180 1181
	req->rl_reply = NULL;

1182
	spin_lock(&buffers->rb_lock);
1183
	buffers->rb_send_count--;
1184
	list_add_tail(&req->rl_free, &buffers->rb_send_bufs);
1185 1186
	if (rep) {
		buffers->rb_recv_count--;
1187
		list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1188
	}
1189
	spin_unlock(&buffers->rb_lock);
1190 1191 1192 1193
}

/*
 * Recover reply buffers from pool.
1194
 * This happens when recovering from disconnect.
1195 1196 1197 1198 1199 1200
 */
void
rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
{
	struct rpcrdma_buffer *buffers = req->rl_buffer;

1201
	spin_lock(&buffers->rb_lock);
1202
	req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1203
	spin_unlock(&buffers->rb_lock);
1204 1205 1206 1207
}

/*
 * Put reply buffers back into pool when not attached to
1208
 * request. This happens in error conditions.
1209 1210 1211 1212
 */
void
rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
{
1213
	struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1214

1215
	spin_lock(&buffers->rb_lock);
1216
	buffers->rb_recv_count--;
1217
	list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1218
	spin_unlock(&buffers->rb_lock);
1219 1220
}

1221
/**
1222
 * rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
1223
 * @size: size of buffer to be allocated, in bytes
1224
 * @direction: direction of data movement
1225 1226
 * @flags: GFP flags
 *
1227 1228
 * Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
 * can be persistently DMA-mapped for I/O.
1229 1230
 *
 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1231 1232
 * receiving the payload of RDMA RECV operations. During Long Calls
 * or Replies they may be registered externally via ro_map.
1233 1234
 */
struct rpcrdma_regbuf *
1235 1236
rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
		     gfp_t flags)
1237 1238 1239 1240 1241
{
	struct rpcrdma_regbuf *rb;

	rb = kmalloc(sizeof(*rb) + size, flags);
	if (rb == NULL)
1242
		return ERR_PTR(-ENOMEM);
1243

1244
	rb->rg_device = NULL;
1245
	rb->rg_direction = direction;
1246
	rb->rg_iov.length = size;
1247

1248
	return rb;
1249
}
1250

1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282
/**
 * __rpcrdma_map_regbuf - DMA-map a regbuf
 * @ia: controlling rpcrdma_ia
 * @rb: regbuf to be mapped
 */
bool
__rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
{
	if (rb->rg_direction == DMA_NONE)
		return false;

	rb->rg_iov.addr = ib_dma_map_single(ia->ri_device,
					    (void *)rb->rg_base,
					    rdmab_length(rb),
					    rb->rg_direction);
	if (ib_dma_mapping_error(ia->ri_device, rdmab_addr(rb)))
		return false;

	rb->rg_device = ia->ri_device;
	rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
	return true;
}

static void
rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb)
{
	if (!rpcrdma_regbuf_is_mapped(rb))
		return;

	ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb),
			    rdmab_length(rb), rb->rg_direction);
	rb->rg_device = NULL;
1283 1284 1285 1286 1287 1288 1289
}

/**
 * rpcrdma_free_regbuf - deregister and free registered buffer
 * @rb: regbuf to be deregistered and freed
 */
void
1290
rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
1291
{
1292 1293 1294
	if (!rb)
		return;

1295
	rpcrdma_dma_unmap_regbuf(rb);
1296
	kfree(rb);
1297 1298
}

1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
/*
 * Prepost any receive buffer, then post send.
 *
 * Receive buffer is donated to hardware, reclaimed upon recv completion.
 */
int
rpcrdma_ep_post(struct rpcrdma_ia *ia,
		struct rpcrdma_ep *ep,
		struct rpcrdma_req *req)
{
1309 1310
	struct ib_send_wr *send_wr = &req->rl_send_wr;
	struct ib_send_wr *send_wr_fail;
1311
	int rc;
1312

1313 1314
	if (req->rl_reply) {
		rc = rpcrdma_ep_post_recv(ia, req->rl_reply);
1315
		if (rc)
1316
			return rc;
1317 1318 1319
		req->rl_reply = NULL;
	}

1320
	dprintk("RPC:       %s: posting %d s/g entries\n",
1321
		__func__, send_wr->num_sge);
1322 1323

	if (DECR_CQCOUNT(ep) > 0)
1324
		send_wr->send_flags = 0;
1325 1326
	else { /* Provider must take a send completion every now and then */
		INIT_CQCOUNT(ep);
1327
		send_wr->send_flags = IB_SEND_SIGNALED;
1328 1329
	}

1330
	rc = ib_post_send(ia->ri_id->qp, send_wr, &send_wr_fail);
1331
	if (rc)
1332 1333 1334 1335 1336 1337
		goto out_postsend_err;
	return 0;

out_postsend_err:
	pr_err("rpcrdma: RDMA Send ib_post_send returned %i\n", rc);
	return -ENOTCONN;
1338 1339 1340 1341 1342 1343
}

int
rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
		     struct rpcrdma_rep *rep)
{
1344
	struct ib_recv_wr *recv_wr_fail;
1345 1346
	int rc;

1347 1348
	if (!rpcrdma_dma_map_regbuf(ia, rep->rr_rdmabuf))
		goto out_map;
1349
	rc = ib_post_recv(ia->ri_id->qp, &rep->rr_recv_wr, &recv_wr_fail);
1350
	if (rc)
1351 1352 1353
		goto out_postrecv;
	return 0;

1354 1355 1356 1357
out_map:
	pr_err("rpcrdma: failed to DMA map the Receive buffer\n");
	return -EIO;

1358 1359 1360
out_postrecv:
	pr_err("rpcrdma: ib_post_recv returned %i\n", rc);
	return -ENOTCONN;
1361
}
1362

1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378
/**
 * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
 * @r_xprt: transport associated with these backchannel resources
 * @min_reqs: minimum number of incoming requests expected
 *
 * Returns zero if all requested buffers were posted, or a negative errno.
 */
int
rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
{
	struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
	struct rpcrdma_rep *rep;
	int rc;

	while (count--) {
1379
		spin_lock(&buffers->rb_lock);
1380 1381 1382
		if (list_empty(&buffers->rb_recv_bufs))
			goto out_reqbuf;
		rep = rpcrdma_buffer_get_rep_locked(buffers);
1383
		spin_unlock(&buffers->rb_lock);
1384

1385
		rc = rpcrdma_ep_post_recv(ia, rep);
1386 1387 1388 1389 1390 1391 1392
		if (rc)
			goto out_rc;
	}

	return 0;

out_reqbuf:
1393
	spin_unlock(&buffers->rb_lock);
1394 1395 1396 1397 1398 1399 1400
	pr_warn("%s: no extra receive buffers\n", __func__);
	return -ENOMEM;

out_rc:
	rpcrdma_recv_buffer_put(rep);
	return rc;
}