1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
3 * Copyright (c) 2015-2018 Oracle. All rights reserved.
4 * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
5 * Copyright (c) 2005-2007 Network Appliance, Inc. All rights reserved.
7 * This software is available to you under a choice of one of two
8 * licenses. You may choose to be licensed under the terms of the GNU
9 * General Public License (GPL) Version 2, available from the file
10 * COPYING in the main directory of this source tree, or the BSD-type
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
17 * Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
20 * Redistributions in binary form must reproduce the above
21 * copyright notice, this list of conditions and the following
22 * disclaimer in the documentation and/or other materials provided
23 * with the distribution.
25 * Neither the name of the Network Appliance, Inc. nor the names of
26 * its contributors may be used to endorse or promote products
27 * derived from this software without specific prior written
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 * Author: Tom Tucker <tom@opengridcomputing.com>
45 #include <linux/interrupt.h>
46 #include <linux/sched.h>
47 #include <linux/slab.h>
48 #include <linux/spinlock.h>
49 #include <linux/workqueue.h>
50 #include <linux/export.h>
52 #include <rdma/ib_verbs.h>
53 #include <rdma/rdma_cm.h>
56 #include <linux/sunrpc/addr.h>
57 #include <linux/sunrpc/debug.h>
58 #include <linux/sunrpc/svc_xprt.h>
59 #include <linux/sunrpc/svc_rdma.h>
61 #include "xprt_rdma.h"
62 #include <trace/events/rpcrdma.h>
64 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
66 static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv,
67 struct net *net, int node);
68 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
70 struct sockaddr *sa, int salen,
72 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt);
73 static void svc_rdma_detach(struct svc_xprt *xprt);
74 static void svc_rdma_free(struct svc_xprt *xprt);
75 static int svc_rdma_has_wspace(struct svc_xprt *xprt);
76 static void svc_rdma_kill_temp_xprt(struct svc_xprt *);
78 static const struct svc_xprt_ops svc_rdma_ops = {
79 .xpo_create = svc_rdma_create,
80 .xpo_recvfrom = svc_rdma_recvfrom,
81 .xpo_sendto = svc_rdma_sendto,
82 .xpo_result_payload = svc_rdma_result_payload,
83 .xpo_release_ctxt = svc_rdma_release_ctxt,
84 .xpo_detach = svc_rdma_detach,
85 .xpo_free = svc_rdma_free,
86 .xpo_has_wspace = svc_rdma_has_wspace,
87 .xpo_accept = svc_rdma_accept,
88 .xpo_kill_temp_xprt = svc_rdma_kill_temp_xprt,
91 struct svc_xprt_class svc_rdma_class = {
93 .xcl_owner = THIS_MODULE,
94 .xcl_ops = &svc_rdma_ops,
95 .xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA,
96 .xcl_ident = XPRT_TRANSPORT_RDMA,
99 /* QP event handler */
100 static void qp_event_handler(struct ib_event *event, void *context)
102 struct svc_xprt *xprt = context;
104 trace_svcrdma_qp_error(event, (struct sockaddr *)&xprt->xpt_remote);
105 switch (event->event) {
106 /* These are considered benign events */
107 case IB_EVENT_PATH_MIG:
108 case IB_EVENT_COMM_EST:
109 case IB_EVENT_SQ_DRAINED:
110 case IB_EVENT_QP_LAST_WQE_REACHED:
113 /* These are considered fatal events */
114 case IB_EVENT_PATH_MIG_ERR:
115 case IB_EVENT_QP_FATAL:
116 case IB_EVENT_QP_REQ_ERR:
117 case IB_EVENT_QP_ACCESS_ERR:
118 case IB_EVENT_DEVICE_FATAL:
120 svc_xprt_deferred_close(xprt);
125 static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv,
126 struct net *net, int node)
128 struct svcxprt_rdma *cma_xprt;
130 cma_xprt = kzalloc_node(sizeof(*cma_xprt), GFP_KERNEL, node);
134 svc_xprt_init(net, &svc_rdma_class, &cma_xprt->sc_xprt, serv);
135 INIT_LIST_HEAD(&cma_xprt->sc_accept_q);
136 INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
137 init_llist_head(&cma_xprt->sc_send_ctxts);
138 init_llist_head(&cma_xprt->sc_recv_ctxts);
139 init_llist_head(&cma_xprt->sc_rw_ctxts);
140 init_waitqueue_head(&cma_xprt->sc_send_wait);
142 spin_lock_init(&cma_xprt->sc_lock);
143 spin_lock_init(&cma_xprt->sc_rq_dto_lock);
144 spin_lock_init(&cma_xprt->sc_send_lock);
145 spin_lock_init(&cma_xprt->sc_rw_ctxt_lock);
148 * Note that this implies that the underlying transport support
149 * has some form of congestion control (see RFC 7530 section 3.1
150 * paragraph 2). For now, we assume that all supported RDMA
151 * transports are suitable here.
153 set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags);
159 svc_rdma_parse_connect_private(struct svcxprt_rdma *newxprt,
160 struct rdma_conn_param *param)
162 const struct rpcrdma_connect_private *pmsg = param->private_data;
165 pmsg->cp_magic == rpcrdma_cmp_magic &&
166 pmsg->cp_version == RPCRDMA_CMP_VERSION) {
167 newxprt->sc_snd_w_inv = pmsg->cp_flags &
168 RPCRDMA_CMP_F_SND_W_INV_OK;
170 dprintk("svcrdma: client send_size %u, recv_size %u "
171 "remote inv %ssupported\n",
172 rpcrdma_decode_buffer_size(pmsg->cp_send_size),
173 rpcrdma_decode_buffer_size(pmsg->cp_recv_size),
174 newxprt->sc_snd_w_inv ? "" : "un");
179 * This function handles the CONNECT_REQUEST event on a listening
180 * endpoint. It is passed the cma_id for the _new_ connection. The context in
181 * this cma_id is inherited from the listening cma_id and is the svc_xprt
182 * structure for the listening endpoint.
184 * This function creates a new xprt for the new connection and enqueues it on
185 * the accept queue for the listent xprt. When the listen thread is kicked, it
186 * will call the recvfrom method on the listen xprt which will accept the new
189 static void handle_connect_req(struct rdma_cm_id *new_cma_id,
190 struct rdma_conn_param *param)
192 struct svcxprt_rdma *listen_xprt = new_cma_id->context;
193 struct svcxprt_rdma *newxprt;
196 newxprt = svc_rdma_create_xprt(listen_xprt->sc_xprt.xpt_server,
197 listen_xprt->sc_xprt.xpt_net,
198 ibdev_to_node(new_cma_id->device));
201 newxprt->sc_cm_id = new_cma_id;
202 new_cma_id->context = newxprt;
203 svc_rdma_parse_connect_private(newxprt, param);
205 /* Save client advertised inbound read limit for use later in accept. */
206 newxprt->sc_ord = param->initiator_depth;
208 sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
209 newxprt->sc_xprt.xpt_remotelen = svc_addr_len(sa);
210 memcpy(&newxprt->sc_xprt.xpt_remote, sa,
211 newxprt->sc_xprt.xpt_remotelen);
212 snprintf(newxprt->sc_xprt.xpt_remotebuf,
213 sizeof(newxprt->sc_xprt.xpt_remotebuf) - 1, "%pISc", sa);
215 /* The remote port is arbitrary and not under the control of the
216 * client ULP. Set it to a fixed value so that the DRC continues
217 * to be effective after a reconnect.
219 rpc_set_port((struct sockaddr *)&newxprt->sc_xprt.xpt_remote, 0);
221 sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
222 svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
225 * Enqueue the new transport on the accept queue of the listening
228 spin_lock(&listen_xprt->sc_lock);
229 list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q);
230 spin_unlock(&listen_xprt->sc_lock);
232 set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags);
233 svc_xprt_enqueue(&listen_xprt->sc_xprt);
237 * svc_rdma_listen_handler - Handle CM events generated on a listening endpoint
238 * @cma_id: the server's listener rdma_cm_id
239 * @event: details of the event
242 * %0: Do not destroy @cma_id
243 * %1: Destroy @cma_id (never returned here)
245 * NB: There is never a DEVICE_REMOVAL event for INADDR_ANY listeners.
247 static int svc_rdma_listen_handler(struct rdma_cm_id *cma_id,
248 struct rdma_cm_event *event)
250 switch (event->event) {
251 case RDMA_CM_EVENT_CONNECT_REQUEST:
252 handle_connect_req(cma_id, &event->param.conn);
261 * svc_rdma_cma_handler - Handle CM events on client connections
262 * @cma_id: the server's listener rdma_cm_id
263 * @event: details of the event
266 * %0: Do not destroy @cma_id
267 * %1: Destroy @cma_id (never returned here)
269 static int svc_rdma_cma_handler(struct rdma_cm_id *cma_id,
270 struct rdma_cm_event *event)
272 struct svcxprt_rdma *rdma = cma_id->context;
273 struct svc_xprt *xprt = &rdma->sc_xprt;
275 switch (event->event) {
276 case RDMA_CM_EVENT_ESTABLISHED:
277 clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags);
279 /* Handle any requests that were received while
280 * CONN_PENDING was set. */
281 svc_xprt_enqueue(xprt);
283 case RDMA_CM_EVENT_DISCONNECTED:
284 case RDMA_CM_EVENT_DEVICE_REMOVAL:
285 svc_xprt_deferred_close(xprt);
294 * Create a listening RDMA service endpoint.
296 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
298 struct sockaddr *sa, int salen,
301 struct rdma_cm_id *listen_id;
302 struct svcxprt_rdma *cma_xprt;
305 if (sa->sa_family != AF_INET && sa->sa_family != AF_INET6)
306 return ERR_PTR(-EAFNOSUPPORT);
307 cma_xprt = svc_rdma_create_xprt(serv, net, NUMA_NO_NODE);
309 return ERR_PTR(-ENOMEM);
310 set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
311 strcpy(cma_xprt->sc_xprt.xpt_remotebuf, "listener");
313 listen_id = rdma_create_id(net, svc_rdma_listen_handler, cma_xprt,
314 RDMA_PS_TCP, IB_QPT_RC);
315 if (IS_ERR(listen_id)) {
316 ret = PTR_ERR(listen_id);
320 /* Allow both IPv4 and IPv6 sockets to bind a single port
323 #if IS_ENABLED(CONFIG_IPV6)
324 ret = rdma_set_afonly(listen_id, 1);
328 ret = rdma_bind_addr(listen_id, sa);
331 cma_xprt->sc_cm_id = listen_id;
333 ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG);
338 * We need to use the address from the cm_id in case the
339 * caller specified 0 for the port number.
341 sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr;
342 svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen);
344 return &cma_xprt->sc_xprt;
347 rdma_destroy_id(listen_id);
354 * This is the xpo_recvfrom function for listening endpoints. Its
355 * purpose is to accept incoming connections. The CMA callback handler
356 * has already created a new transport and attached it to the new CMA
359 * There is a queue of pending connections hung on the listening
360 * transport. This queue contains the new svc_xprt structure. This
361 * function takes svc_xprt structures off the accept_q and completes
364 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
366 struct svcxprt_rdma *listen_rdma;
367 struct svcxprt_rdma *newxprt = NULL;
368 struct rdma_conn_param conn_param;
369 struct rpcrdma_connect_private pmsg;
370 struct ib_qp_init_attr qp_attr;
371 unsigned int ctxts, rq_depth;
372 struct ib_device *dev;
374 RPC_IFDEBUG(struct sockaddr *sap);
376 listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
377 clear_bit(XPT_CONN, &xprt->xpt_flags);
378 /* Get the next entry off the accept list */
379 spin_lock(&listen_rdma->sc_lock);
380 if (!list_empty(&listen_rdma->sc_accept_q)) {
381 newxprt = list_entry(listen_rdma->sc_accept_q.next,
382 struct svcxprt_rdma, sc_accept_q);
383 list_del_init(&newxprt->sc_accept_q);
385 if (!list_empty(&listen_rdma->sc_accept_q))
386 set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags);
387 spin_unlock(&listen_rdma->sc_lock);
391 dev = newxprt->sc_cm_id->device;
392 newxprt->sc_port_num = newxprt->sc_cm_id->port_num;
394 /* Qualify the transport resource defaults with the
395 * capabilities of this particular device */
396 /* Transport header, head iovec, tail iovec */
397 newxprt->sc_max_send_sges = 3;
398 /* Add one SGE per page list entry */
399 newxprt->sc_max_send_sges += (svcrdma_max_req_size / PAGE_SIZE) + 1;
400 if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge)
401 newxprt->sc_max_send_sges = dev->attrs.max_send_sge;
402 newxprt->sc_max_req_size = svcrdma_max_req_size;
403 newxprt->sc_max_requests = svcrdma_max_requests;
404 newxprt->sc_max_bc_requests = svcrdma_max_bc_requests;
405 newxprt->sc_recv_batch = RPCRDMA_MAX_RECV_BATCH;
406 rq_depth = newxprt->sc_max_requests + newxprt->sc_max_bc_requests +
407 newxprt->sc_recv_batch;
408 if (rq_depth > dev->attrs.max_qp_wr) {
409 pr_warn("svcrdma: reducing receive depth to %d\n",
410 dev->attrs.max_qp_wr);
411 rq_depth = dev->attrs.max_qp_wr;
412 newxprt->sc_recv_batch = 1;
413 newxprt->sc_max_requests = rq_depth - 2;
414 newxprt->sc_max_bc_requests = 2;
416 newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests);
417 ctxts = rdma_rw_mr_factor(dev, newxprt->sc_port_num, RPCSVC_MAXPAGES);
418 ctxts *= newxprt->sc_max_requests;
419 newxprt->sc_sq_depth = rq_depth + ctxts;
420 if (newxprt->sc_sq_depth > dev->attrs.max_qp_wr) {
421 pr_warn("svcrdma: reducing send depth to %d\n",
422 dev->attrs.max_qp_wr);
423 newxprt->sc_sq_depth = dev->attrs.max_qp_wr;
425 atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth);
427 newxprt->sc_pd = ib_alloc_pd(dev, 0);
428 if (IS_ERR(newxprt->sc_pd)) {
429 trace_svcrdma_pd_err(newxprt, PTR_ERR(newxprt->sc_pd));
432 newxprt->sc_sq_cq = ib_alloc_cq_any(dev, newxprt, newxprt->sc_sq_depth,
434 if (IS_ERR(newxprt->sc_sq_cq))
437 ib_alloc_cq_any(dev, newxprt, rq_depth, IB_POLL_WORKQUEUE);
438 if (IS_ERR(newxprt->sc_rq_cq))
441 memset(&qp_attr, 0, sizeof qp_attr);
442 qp_attr.event_handler = qp_event_handler;
443 qp_attr.qp_context = &newxprt->sc_xprt;
444 qp_attr.port_num = newxprt->sc_port_num;
445 qp_attr.cap.max_rdma_ctxs = ctxts;
446 qp_attr.cap.max_send_wr = newxprt->sc_sq_depth - ctxts;
447 qp_attr.cap.max_recv_wr = rq_depth;
448 qp_attr.cap.max_send_sge = newxprt->sc_max_send_sges;
449 qp_attr.cap.max_recv_sge = 1;
450 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
451 qp_attr.qp_type = IB_QPT_RC;
452 qp_attr.send_cq = newxprt->sc_sq_cq;
453 qp_attr.recv_cq = newxprt->sc_rq_cq;
454 dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n",
455 newxprt->sc_cm_id, newxprt->sc_pd);
456 dprintk(" cap.max_send_wr = %d, cap.max_recv_wr = %d\n",
457 qp_attr.cap.max_send_wr, qp_attr.cap.max_recv_wr);
458 dprintk(" cap.max_send_sge = %d, cap.max_recv_sge = %d\n",
459 qp_attr.cap.max_send_sge, qp_attr.cap.max_recv_sge);
461 ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr);
463 trace_svcrdma_qp_err(newxprt, ret);
466 newxprt->sc_qp = newxprt->sc_cm_id->qp;
468 if (!(dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
469 newxprt->sc_snd_w_inv = false;
470 if (!rdma_protocol_iwarp(dev, newxprt->sc_port_num) &&
471 !rdma_ib_or_roce(dev, newxprt->sc_port_num)) {
472 trace_svcrdma_fabric_err(newxprt, -EINVAL);
476 if (!svc_rdma_post_recvs(newxprt))
479 /* Construct RDMA-CM private message */
480 pmsg.cp_magic = rpcrdma_cmp_magic;
481 pmsg.cp_version = RPCRDMA_CMP_VERSION;
483 pmsg.cp_send_size = pmsg.cp_recv_size =
484 rpcrdma_encode_buffer_size(newxprt->sc_max_req_size);
486 /* Accept Connection */
487 set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags);
488 memset(&conn_param, 0, sizeof conn_param);
489 conn_param.responder_resources = 0;
490 conn_param.initiator_depth = min_t(int, newxprt->sc_ord,
491 dev->attrs.max_qp_init_rd_atom);
492 if (!conn_param.initiator_depth) {
494 trace_svcrdma_initdepth_err(newxprt, ret);
497 conn_param.private_data = &pmsg;
498 conn_param.private_data_len = sizeof(pmsg);
499 rdma_lock_handler(newxprt->sc_cm_id);
500 newxprt->sc_cm_id->event_handler = svc_rdma_cma_handler;
501 ret = rdma_accept(newxprt->sc_cm_id, &conn_param);
502 rdma_unlock_handler(newxprt->sc_cm_id);
504 trace_svcrdma_accept_err(newxprt, ret);
508 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
509 dprintk("svcrdma: new connection %p accepted:\n", newxprt);
510 sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
511 dprintk(" local address : %pIS:%u\n", sap, rpc_get_port(sap));
512 sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
513 dprintk(" remote address : %pIS:%u\n", sap, rpc_get_port(sap));
514 dprintk(" max_sge : %d\n", newxprt->sc_max_send_sges);
515 dprintk(" sq_depth : %d\n", newxprt->sc_sq_depth);
516 dprintk(" rdma_rw_ctxs : %d\n", ctxts);
517 dprintk(" max_requests : %d\n", newxprt->sc_max_requests);
518 dprintk(" ord : %d\n", conn_param.initiator_depth);
521 return &newxprt->sc_xprt;
524 /* Take a reference in case the DTO handler runs */
525 svc_xprt_get(&newxprt->sc_xprt);
526 if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
527 ib_destroy_qp(newxprt->sc_qp);
528 rdma_destroy_id(newxprt->sc_cm_id);
529 /* This call to put will destroy the transport */
530 svc_xprt_put(&newxprt->sc_xprt);
534 static void svc_rdma_detach(struct svc_xprt *xprt)
536 struct svcxprt_rdma *rdma =
537 container_of(xprt, struct svcxprt_rdma, sc_xprt);
539 rdma_disconnect(rdma->sc_cm_id);
542 static void __svc_rdma_free(struct work_struct *work)
544 struct svcxprt_rdma *rdma =
545 container_of(work, struct svcxprt_rdma, sc_work);
547 /* This blocks until the Completion Queues are empty */
548 if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
549 ib_drain_qp(rdma->sc_qp);
551 svc_rdma_flush_recv_queues(rdma);
553 svc_rdma_destroy_rw_ctxts(rdma);
554 svc_rdma_send_ctxts_destroy(rdma);
555 svc_rdma_recv_ctxts_destroy(rdma);
557 /* Destroy the QP if present (not a listener) */
558 if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
559 ib_destroy_qp(rdma->sc_qp);
561 if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
562 ib_free_cq(rdma->sc_sq_cq);
564 if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
565 ib_free_cq(rdma->sc_rq_cq);
567 if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
568 ib_dealloc_pd(rdma->sc_pd);
570 /* Destroy the CM ID */
571 rdma_destroy_id(rdma->sc_cm_id);
576 static void svc_rdma_free(struct svc_xprt *xprt)
578 struct svcxprt_rdma *rdma =
579 container_of(xprt, struct svcxprt_rdma, sc_xprt);
581 INIT_WORK(&rdma->sc_work, __svc_rdma_free);
582 schedule_work(&rdma->sc_work);
585 static int svc_rdma_has_wspace(struct svc_xprt *xprt)
587 struct svcxprt_rdma *rdma =
588 container_of(xprt, struct svcxprt_rdma, sc_xprt);
591 * If there are already waiters on the SQ,
594 if (waitqueue_active(&rdma->sc_send_wait))
597 /* Otherwise return true. */
601 static void svc_rdma_kill_temp_xprt(struct svc_xprt *xprt)