1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * RDMA transport layer based on the trans_fd.c implementation.
4 *
5 * Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
6 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
7 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
8 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/in.h>
15 #include <linux/module.h>
16 #include <linux/net.h>
17 #include <linux/ipv6.h>
18 #include <linux/kthread.h>
19 #include <linux/errno.h>
20 #include <linux/kernel.h>
21 #include <linux/un.h>
22 #include <linux/uaccess.h>
23 #include <linux/inet.h>
24 #include <linux/file.h>
25 #include <linux/fs_context.h>
26 #include <linux/semaphore.h>
27 #include <linux/slab.h>
28 #include <linux/seq_file.h>
29 #include <net/9p/9p.h>
30 #include <net/9p/client.h>
31 #include <net/9p/transport.h>
32 #include <rdma/ib_verbs.h>
33 #include <rdma/rdma_cm.h>
34
35 #define P9_RDMA_SEND_SGE 4
36 #define P9_RDMA_RECV_SGE 4
37 #define P9_RDMA_IRD 0
38 #define P9_RDMA_ORD 0
39 #define P9_RDMA_MAXSIZE (1024*1024) /* 1MB */
40
41 /**
42 * struct p9_trans_rdma - RDMA transport instance
43 *
44 * @state: tracks the transport state machine for connection setup and tear down
45 * @cm_id: The RDMA CM ID
46 * @pd: Protection Domain pointer
47 * @qp: Queue Pair pointer
48 * @cq: Completion Queue pointer
49 * @timeout: Number of uSecs to wait for connection management events
50 * @privport: Whether a privileged port may be used
51 * @port: The port to use
52 * @sq_depth: The depth of the Send Queue
53 * @sq_sem: Semaphore for the SQ
54 * @rq_depth: The depth of the Receive Queue.
55 * @rq_sem: Semaphore for the RQ
56 * @excess_rc : Amount of posted Receive Contexts without a pending request.
57 * See rdma_request()
58 * @addr: The remote peer's address
59 * @req_lock: Protects the active request list
60 * @cm_done: Completion event for connection management tracking
61 */
62 struct p9_trans_rdma {
63 enum {
64 P9_RDMA_INIT,
65 P9_RDMA_ADDR_RESOLVED,
66 P9_RDMA_ROUTE_RESOLVED,
67 P9_RDMA_CONNECTED,
68 P9_RDMA_FLUSHING,
69 P9_RDMA_CLOSING,
70 P9_RDMA_CLOSED,
71 } state;
72 struct rdma_cm_id *cm_id;
73 struct ib_pd *pd;
74 struct ib_qp *qp;
75 struct ib_cq *cq;
76 long timeout;
77 bool privport;
78 u16 port;
79 int sq_depth;
80 struct semaphore sq_sem;
81 int rq_depth;
82 struct semaphore rq_sem;
83 atomic_t excess_rc;
84 struct sockaddr_in addr;
85 spinlock_t req_lock;
86
87 struct completion cm_done;
88 };
89
90 struct p9_rdma_req;
91
92 /**
93 * struct p9_rdma_context - Keeps track of in-process WR
94 *
95 * @cqe: completion queue entry
96 * @busa: Bus address to unmap when the WR completes
97 * @req: Keeps track of requests (send)
98 * @rc: Keepts track of replies (receive)
99 */
100 struct p9_rdma_context {
101 struct ib_cqe cqe;
102 dma_addr_t busa;
103 union {
104 struct p9_req_t *req;
105 struct p9_fcall rc;
106 };
107 };
108
p9_rdma_show_options(struct seq_file * m,struct p9_client * clnt)109 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
110 {
111 struct p9_trans_rdma *rdma = clnt->trans;
112
113 if (rdma->port != P9_RDMA_PORT)
114 seq_printf(m, ",port=%u", rdma->port);
115 if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
116 seq_printf(m, ",sq=%u", rdma->sq_depth);
117 if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
118 seq_printf(m, ",rq=%u", rdma->rq_depth);
119 if (rdma->timeout != P9_RDMA_TIMEOUT)
120 seq_printf(m, ",timeout=%lu", rdma->timeout);
121 if (rdma->privport)
122 seq_puts(m, ",privport");
123 return 0;
124 }
125
126 static int
p9_cm_event_handler(struct rdma_cm_id * id,struct rdma_cm_event * event)127 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
128 {
129 struct p9_client *c = id->context;
130 struct p9_trans_rdma *rdma = c->trans;
131 switch (event->event) {
132 case RDMA_CM_EVENT_ADDR_RESOLVED:
133 BUG_ON(rdma->state != P9_RDMA_INIT);
134 rdma->state = P9_RDMA_ADDR_RESOLVED;
135 break;
136
137 case RDMA_CM_EVENT_ROUTE_RESOLVED:
138 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
139 rdma->state = P9_RDMA_ROUTE_RESOLVED;
140 break;
141
142 case RDMA_CM_EVENT_ESTABLISHED:
143 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
144 rdma->state = P9_RDMA_CONNECTED;
145 break;
146
147 case RDMA_CM_EVENT_DISCONNECTED:
148 if (rdma)
149 rdma->state = P9_RDMA_CLOSED;
150 c->status = Disconnected;
151 break;
152
153 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
154 break;
155
156 case RDMA_CM_EVENT_ADDR_CHANGE:
157 case RDMA_CM_EVENT_ROUTE_ERROR:
158 case RDMA_CM_EVENT_DEVICE_REMOVAL:
159 case RDMA_CM_EVENT_MULTICAST_JOIN:
160 case RDMA_CM_EVENT_MULTICAST_ERROR:
161 case RDMA_CM_EVENT_REJECTED:
162 case RDMA_CM_EVENT_CONNECT_REQUEST:
163 case RDMA_CM_EVENT_CONNECT_RESPONSE:
164 case RDMA_CM_EVENT_CONNECT_ERROR:
165 case RDMA_CM_EVENT_ADDR_ERROR:
166 case RDMA_CM_EVENT_UNREACHABLE:
167 c->status = Disconnected;
168 rdma_disconnect(rdma->cm_id);
169 break;
170 default:
171 BUG();
172 }
173 complete(&rdma->cm_done);
174 return 0;
175 }
176
177 static void
recv_done(struct ib_cq * cq,struct ib_wc * wc)178 recv_done(struct ib_cq *cq, struct ib_wc *wc)
179 {
180 struct p9_client *client = cq->cq_context;
181 struct p9_trans_rdma *rdma = client->trans;
182 struct p9_rdma_context *c =
183 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
184 struct p9_req_t *req;
185 int err = 0;
186 int16_t tag;
187
188 req = NULL;
189 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
190 DMA_FROM_DEVICE);
191
192 if (wc->status != IB_WC_SUCCESS)
193 goto err_out;
194
195 c->rc.size = wc->byte_len;
196 err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1);
197 if (err)
198 goto err_out;
199
200 req = p9_tag_lookup(client, tag);
201 if (!req)
202 goto err_out;
203
204 /* Check that we have not yet received a reply for this request.
205 */
206 if (unlikely(req->rc.sdata)) {
207 pr_err("Duplicate reply for request %d", tag);
208 goto err_out;
209 }
210
211 req->rc.size = c->rc.size;
212 req->rc.sdata = c->rc.sdata;
213 p9_client_cb(client, req, REQ_STATUS_RCVD);
214
215 out:
216 up(&rdma->rq_sem);
217 kfree(c);
218 return;
219
220 err_out:
221 p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
222 req, err, wc->status);
223 rdma->state = P9_RDMA_FLUSHING;
224 client->status = Disconnected;
225 goto out;
226 }
227
228 static void
send_done(struct ib_cq * cq,struct ib_wc * wc)229 send_done(struct ib_cq *cq, struct ib_wc *wc)
230 {
231 struct p9_client *client = cq->cq_context;
232 struct p9_trans_rdma *rdma = client->trans;
233 struct p9_rdma_context *c =
234 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
235
236 ib_dma_unmap_single(rdma->cm_id->device,
237 c->busa, c->req->tc.size,
238 DMA_TO_DEVICE);
239 up(&rdma->sq_sem);
240 p9_req_put(client, c->req);
241 kfree(c);
242 }
243
qp_event_handler(struct ib_event * event,void * context)244 static void qp_event_handler(struct ib_event *event, void *context)
245 {
246 p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
247 event->event, context);
248 }
249
rdma_destroy_trans(struct p9_trans_rdma * rdma)250 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
251 {
252 if (!rdma)
253 return;
254
255 if (rdma->qp && !IS_ERR(rdma->qp))
256 ib_destroy_qp(rdma->qp);
257
258 if (rdma->pd && !IS_ERR(rdma->pd))
259 ib_dealloc_pd(rdma->pd);
260
261 if (rdma->cq && !IS_ERR(rdma->cq))
262 ib_free_cq(rdma->cq);
263
264 if (rdma->cm_id && !IS_ERR(rdma->cm_id))
265 rdma_destroy_id(rdma->cm_id);
266
267 kfree(rdma);
268 }
269
270 static int
post_recv(struct p9_client * client,struct p9_rdma_context * c)271 post_recv(struct p9_client *client, struct p9_rdma_context *c)
272 {
273 struct p9_trans_rdma *rdma = client->trans;
274 struct ib_recv_wr wr;
275 struct ib_sge sge;
276 int ret;
277
278 c->busa = ib_dma_map_single(rdma->cm_id->device,
279 c->rc.sdata, client->msize,
280 DMA_FROM_DEVICE);
281 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
282 goto error;
283
284 c->cqe.done = recv_done;
285
286 sge.addr = c->busa;
287 sge.length = client->msize;
288 sge.lkey = rdma->pd->local_dma_lkey;
289
290 wr.next = NULL;
291 wr.wr_cqe = &c->cqe;
292 wr.sg_list = &sge;
293 wr.num_sge = 1;
294
295 ret = ib_post_recv(rdma->qp, &wr, NULL);
296 if (ret)
297 ib_dma_unmap_single(rdma->cm_id->device, c->busa,
298 client->msize, DMA_FROM_DEVICE);
299 return ret;
300
301 error:
302 p9_debug(P9_DEBUG_ERROR, "EIO\n");
303 return -EIO;
304 }
305
rdma_request(struct p9_client * client,struct p9_req_t * req)306 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
307 {
308 struct p9_trans_rdma *rdma = client->trans;
309 struct ib_send_wr wr;
310 struct ib_sge sge;
311 int err = 0;
312 unsigned long flags;
313 struct p9_rdma_context *c = NULL;
314 struct p9_rdma_context *rpl_context = NULL;
315
316 /* When an error occurs between posting the recv and the send,
317 * there will be a receive context posted without a pending request.
318 * Since there is no way to "un-post" it, we remember it and skip
319 * post_recv() for the next request.
320 * So here,
321 * see if we are this `next request' and need to absorb an excess rc.
322 * If yes, then drop and free our own, and do not recv_post().
323 **/
324 if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
325 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
326 /* Got one! */
327 p9_fcall_fini(&req->rc);
328 req->rc.sdata = NULL;
329 goto dont_need_post_recv;
330 } else {
331 /* We raced and lost. */
332 atomic_inc(&rdma->excess_rc);
333 }
334 }
335
336 /* Allocate an fcall for the reply */
337 rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
338 if (!rpl_context) {
339 err = -ENOMEM;
340 goto recv_error;
341 }
342 rpl_context->rc.sdata = req->rc.sdata;
343
344 /*
345 * Post a receive buffer for this request. We need to ensure
346 * there is a reply buffer available for every outstanding
347 * request. A flushed request can result in no reply for an
348 * outstanding request, so we must keep a count to avoid
349 * overflowing the RQ.
350 */
351 if (down_interruptible(&rdma->rq_sem)) {
352 err = -EINTR;
353 goto recv_error;
354 }
355
356 err = post_recv(client, rpl_context);
357 if (err) {
358 p9_debug(P9_DEBUG_ERROR, "POST RECV failed: %d\n", err);
359 goto recv_error;
360 }
361 /* remove posted receive buffer from request structure */
362 req->rc.sdata = NULL;
363
364 dont_need_post_recv:
365 /* Post the request */
366 c = kmalloc(sizeof *c, GFP_NOFS);
367 if (!c) {
368 err = -ENOMEM;
369 goto send_error;
370 }
371 c->req = req;
372
373 c->busa = ib_dma_map_single(rdma->cm_id->device,
374 c->req->tc.sdata, c->req->tc.size,
375 DMA_TO_DEVICE);
376 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
377 err = -EIO;
378 goto send_error;
379 }
380
381 c->cqe.done = send_done;
382
383 sge.addr = c->busa;
384 sge.length = c->req->tc.size;
385 sge.lkey = rdma->pd->local_dma_lkey;
386
387 wr.next = NULL;
388 wr.wr_cqe = &c->cqe;
389 wr.opcode = IB_WR_SEND;
390 wr.send_flags = IB_SEND_SIGNALED;
391 wr.sg_list = &sge;
392 wr.num_sge = 1;
393
394 if (down_interruptible(&rdma->sq_sem)) {
395 err = -EINTR;
396 goto dma_unmap;
397 }
398
399 /* Mark request as `sent' *before* we actually send it,
400 * because doing if after could erase the REQ_STATUS_RCVD
401 * status in case of a very fast reply.
402 */
403 WRITE_ONCE(req->status, REQ_STATUS_SENT);
404 err = ib_post_send(rdma->qp, &wr, NULL);
405 if (err)
406 goto dma_unmap;
407
408 /* Success */
409 return 0;
410
411 dma_unmap:
412 ib_dma_unmap_single(rdma->cm_id->device, c->busa,
413 c->req->tc.size, DMA_TO_DEVICE);
414 /* Handle errors that happened during or while preparing the send: */
415 send_error:
416 WRITE_ONCE(req->status, REQ_STATUS_ERROR);
417 kfree(c);
418 p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
419
420 /* Ach.
421 * We did recv_post(), but not send. We have one recv_post in excess.
422 */
423 atomic_inc(&rdma->excess_rc);
424 return err;
425
426 /* Handle errors that happened during or while preparing post_recv(): */
427 recv_error:
428 kfree(rpl_context);
429 spin_lock_irqsave(&rdma->req_lock, flags);
430 if (err != -EINTR && rdma->state < P9_RDMA_CLOSING) {
431 rdma->state = P9_RDMA_CLOSING;
432 spin_unlock_irqrestore(&rdma->req_lock, flags);
433 rdma_disconnect(rdma->cm_id);
434 } else
435 spin_unlock_irqrestore(&rdma->req_lock, flags);
436 return err;
437 }
438
rdma_close(struct p9_client * client)439 static void rdma_close(struct p9_client *client)
440 {
441 struct p9_trans_rdma *rdma;
442
443 if (!client)
444 return;
445
446 rdma = client->trans;
447 if (!rdma)
448 return;
449
450 client->status = Disconnected;
451 rdma_disconnect(rdma->cm_id);
452 rdma_destroy_trans(rdma);
453 }
454
455 /**
456 * alloc_rdma - Allocate and initialize the rdma transport structure
457 * @opts: Mount options structure
458 */
alloc_rdma(struct p9_rdma_opts * opts)459 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
460 {
461 struct p9_trans_rdma *rdma;
462
463 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
464 if (!rdma)
465 return NULL;
466
467 rdma->port = opts->port;
468 rdma->privport = opts->privport;
469 rdma->sq_depth = opts->sq_depth;
470 rdma->rq_depth = opts->rq_depth;
471 rdma->timeout = opts->timeout;
472 spin_lock_init(&rdma->req_lock);
473 init_completion(&rdma->cm_done);
474 sema_init(&rdma->sq_sem, rdma->sq_depth);
475 sema_init(&rdma->rq_sem, rdma->rq_depth);
476 atomic_set(&rdma->excess_rc, 0);
477
478 return rdma;
479 }
480
rdma_cancel(struct p9_client * client,struct p9_req_t * req)481 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
482 {
483 /* Nothing to do here.
484 * We will take care of it (if we have to) in rdma_cancelled()
485 */
486 return 1;
487 }
488
489 /* A request has been fully flushed without a reply.
490 * That means we have posted one buffer in excess.
491 */
rdma_cancelled(struct p9_client * client,struct p9_req_t * req)492 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
493 {
494 struct p9_trans_rdma *rdma = client->trans;
495 atomic_inc(&rdma->excess_rc);
496 return 0;
497 }
498
p9_rdma_bind_privport(struct p9_trans_rdma * rdma)499 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
500 {
501 struct sockaddr_in cl = {
502 .sin_family = AF_INET,
503 .sin_addr.s_addr = htonl(INADDR_ANY),
504 };
505 int port, err = -EINVAL;
506
507 for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
508 cl.sin_port = htons((ushort)port);
509 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
510 if (err != -EADDRINUSE)
511 break;
512 }
513 return err;
514 }
515
516 /**
517 * rdma_create_trans - Transport method for creating a transport instance
518 * @client: client instance
519 * @fc: The filesystem context
520 */
521 static int
rdma_create_trans(struct p9_client * client,struct fs_context * fc)522 rdma_create_trans(struct p9_client *client, struct fs_context *fc)
523 {
524 const char *addr = fc->source;
525 struct v9fs_context *ctx = fc->fs_private;
526 struct p9_rdma_opts opts = ctx->rdma_opts;
527 int err;
528 struct p9_trans_rdma *rdma;
529 struct rdma_conn_param conn_param;
530 struct ib_qp_init_attr qp_attr;
531
532 if (addr == NULL)
533 return -EINVAL;
534
535 /* options are already parsed, in the fs context */
536 opts = ctx->rdma_opts;
537
538 /* Create and initialize the RDMA transport structure */
539 rdma = alloc_rdma(&opts);
540 if (!rdma)
541 return -ENOMEM;
542
543 /* Create the RDMA CM ID */
544 rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
545 RDMA_PS_TCP, IB_QPT_RC);
546 if (IS_ERR(rdma->cm_id))
547 goto error;
548
549 /* Associate the client with the transport */
550 client->trans = rdma;
551
552 /* Bind to a privileged port if we need to */
553 if (opts.privport) {
554 err = p9_rdma_bind_privport(rdma);
555 if (err < 0) {
556 pr_err("%s (%d): problem binding to privport: %d\n",
557 __func__, task_pid_nr(current), -err);
558 goto error;
559 }
560 }
561
562 /* Resolve the server's address */
563 rdma->addr.sin_family = AF_INET;
564 rdma->addr.sin_addr.s_addr = in_aton(addr);
565 rdma->addr.sin_port = htons(opts.port);
566 err = rdma_resolve_addr(rdma->cm_id, NULL,
567 (struct sockaddr *)&rdma->addr,
568 rdma->timeout);
569 if (err)
570 goto error;
571 err = wait_for_completion_interruptible(&rdma->cm_done);
572 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
573 goto error;
574
575 /* Resolve the route to the server */
576 err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
577 if (err)
578 goto error;
579 err = wait_for_completion_interruptible(&rdma->cm_done);
580 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
581 goto error;
582
583 /* Create the Completion Queue */
584 rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
585 opts.sq_depth + opts.rq_depth + 1,
586 IB_POLL_SOFTIRQ);
587 if (IS_ERR(rdma->cq))
588 goto error;
589
590 /* Create the Protection Domain */
591 rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
592 if (IS_ERR(rdma->pd))
593 goto error;
594
595 /* Create the Queue Pair */
596 memset(&qp_attr, 0, sizeof qp_attr);
597 qp_attr.event_handler = qp_event_handler;
598 qp_attr.qp_context = client;
599 qp_attr.cap.max_send_wr = opts.sq_depth;
600 qp_attr.cap.max_recv_wr = opts.rq_depth;
601 qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
602 qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
603 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
604 qp_attr.qp_type = IB_QPT_RC;
605 qp_attr.send_cq = rdma->cq;
606 qp_attr.recv_cq = rdma->cq;
607 err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
608 if (err)
609 goto error;
610 rdma->qp = rdma->cm_id->qp;
611
612 /* Request a connection */
613 memset(&conn_param, 0, sizeof(conn_param));
614 conn_param.private_data = NULL;
615 conn_param.private_data_len = 0;
616 conn_param.responder_resources = P9_RDMA_IRD;
617 conn_param.initiator_depth = P9_RDMA_ORD;
618 err = rdma_connect(rdma->cm_id, &conn_param);
619 if (err)
620 goto error;
621 err = wait_for_completion_interruptible(&rdma->cm_done);
622 if (err || (rdma->state != P9_RDMA_CONNECTED))
623 goto error;
624
625 client->status = Connected;
626
627 return 0;
628
629 error:
630 rdma_destroy_trans(rdma);
631 return -ENOTCONN;
632 }
633
634 static struct p9_trans_module p9_rdma_trans = {
635 .name = "rdma",
636 .maxsize = P9_RDMA_MAXSIZE,
637 .pooled_rbuffers = true,
638 .def = false,
639 .supports_vmalloc = false,
640 .owner = THIS_MODULE,
641 .create = rdma_create_trans,
642 .close = rdma_close,
643 .request = rdma_request,
644 .cancel = rdma_cancel,
645 .cancelled = rdma_cancelled,
646 .show_options = p9_rdma_show_options,
647 };
648
649 /**
650 * p9_trans_rdma_init - Register the 9P RDMA transport driver
651 */
p9_trans_rdma_init(void)652 static int __init p9_trans_rdma_init(void)
653 {
654 v9fs_register_trans(&p9_rdma_trans);
655 return 0;
656 }
657
p9_trans_rdma_exit(void)658 static void __exit p9_trans_rdma_exit(void)
659 {
660 v9fs_unregister_trans(&p9_rdma_trans);
661 }
662
663 module_init(p9_trans_rdma_init);
664 module_exit(p9_trans_rdma_exit);
665 MODULE_ALIAS_9P("rdma");
666
667 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
668 MODULE_DESCRIPTION("RDMA Transport for 9P");
669 MODULE_LICENSE("Dual BSD/GPL");
670