net: remove redundant argument comments
[linux-2.6.git] / net / 9p / trans_rdma.c
1 /*
2  * linux/fs/9p/trans_rdma.c
3  *
4  * RDMA transport layer based on the trans_fd.c implementation.
5  *
6  *  Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
7  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
8  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
9  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
10  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License version 2
14  *  as published by the Free Software Foundation.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  *  GNU General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; if not, write to:
23  *  Free Software Foundation
24  *  51 Franklin Street, Fifth Floor
25  *  Boston, MA  02111-1301  USA
26  *
27  */
28
29 #include <linux/in.h>
30 #include <linux/module.h>
31 #include <linux/net.h>
32 #include <linux/ipv6.h>
33 #include <linux/kthread.h>
34 #include <linux/errno.h>
35 #include <linux/kernel.h>
36 #include <linux/un.h>
37 #include <linux/uaccess.h>
38 #include <linux/inet.h>
39 #include <linux/idr.h>
40 #include <linux/file.h>
41 #include <linux/parser.h>
42 #include <linux/semaphore.h>
43 #include <net/9p/9p.h>
44 #include <net/9p/client.h>
45 #include <net/9p/transport.h>
46 #include <rdma/ib_verbs.h>
47 #include <rdma/rdma_cm.h>
48
49 #define P9_PORT                 5640
50 #define P9_RDMA_SQ_DEPTH        32
51 #define P9_RDMA_RQ_DEPTH        32
52 #define P9_RDMA_SEND_SGE        4
53 #define P9_RDMA_RECV_SGE        4
54 #define P9_RDMA_IRD             0
55 #define P9_RDMA_ORD             0
56 #define P9_RDMA_TIMEOUT         30000           /* 30 seconds */
57 #define P9_RDMA_MAXSIZE         (4*4096)        /* Min SGE is 4, so we can
58                                                  * safely advertise a maxsize
59                                                  * of 64k */
60
61 #define P9_RDMA_MAX_SGE (P9_RDMA_MAXSIZE >> PAGE_SHIFT)
62 /**
63  * struct p9_trans_rdma - RDMA transport instance
64  *
65  * @state: tracks the transport state machine for connection setup and tear down
66  * @cm_id: The RDMA CM ID
67  * @pd: Protection Domain pointer
68  * @qp: Queue Pair pointer
69  * @cq: Completion Queue pointer
70  * @lkey: The local access only memory region key
71  * @timeout: Number of uSecs to wait for connection management events
72  * @sq_depth: The depth of the Send Queue
73  * @sq_sem: Semaphore for the SQ
74  * @rq_depth: The depth of the Receive Queue.
75  * @addr: The remote peer's address
76  * @req_lock: Protects the active request list
77  * @send_wait: Wait list when the SQ fills up
78  * @cm_done: Completion event for connection management tracking
79  */
80 struct p9_trans_rdma {
81         enum {
82                 P9_RDMA_INIT,
83                 P9_RDMA_ADDR_RESOLVED,
84                 P9_RDMA_ROUTE_RESOLVED,
85                 P9_RDMA_CONNECTED,
86                 P9_RDMA_FLUSHING,
87                 P9_RDMA_CLOSING,
88                 P9_RDMA_CLOSED,
89         } state;
90         struct rdma_cm_id *cm_id;
91         struct ib_pd *pd;
92         struct ib_qp *qp;
93         struct ib_cq *cq;
94         struct ib_mr *dma_mr;
95         u32 lkey;
96         long timeout;
97         int sq_depth;
98         struct semaphore sq_sem;
99         int rq_depth;
100         atomic_t rq_count;
101         struct sockaddr_in addr;
102         spinlock_t req_lock;
103
104         struct completion cm_done;
105 };
106
107 /**
108  * p9_rdma_context - Keeps track of in-process WR
109  *
110  * @wc_op: The original WR op for when the CQE completes in error.
111  * @busa: Bus address to unmap when the WR completes
112  * @req: Keeps track of requests (send)
113  * @rc: Keepts track of replies (receive)
114  */
115 struct p9_rdma_req;
116 struct p9_rdma_context {
117         enum ib_wc_opcode wc_op;
118         dma_addr_t busa;
119         union {
120                 struct p9_req_t *req;
121                 struct p9_fcall *rc;
122         };
123 };
124
125 /**
126  * p9_rdma_opts - Collection of mount options
127  * @port: port of connection
128  * @sq_depth: The requested depth of the SQ. This really doesn't need
129  * to be any deeper than the number of threads used in the client
130  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
131  * @timeout: Time to wait in msecs for CM events
132  */
133 struct p9_rdma_opts {
134         short port;
135         int sq_depth;
136         int rq_depth;
137         long timeout;
138 };
139
140 /*
141  * Option Parsing (code inspired by NFS code)
142  */
143 enum {
144         /* Options that take integer arguments */
145         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
146 };
147
148 static match_table_t tokens = {
149         {Opt_port, "port=%u"},
150         {Opt_sq_depth, "sq=%u"},
151         {Opt_rq_depth, "rq=%u"},
152         {Opt_timeout, "timeout=%u"},
153         {Opt_err, NULL},
154 };
155
156 /**
157  * parse_options - parse mount options into session structure
158  * @options: options string passed from mount
159  * @opts: transport-specific structure to parse options into
160  *
161  * Returns 0 upon success, -ERRNO upon failure
162  */
163 static int parse_opts(char *params, struct p9_rdma_opts *opts)
164 {
165         char *p;
166         substring_t args[MAX_OPT_ARGS];
167         int option;
168         char *options;
169         int ret;
170
171         opts->port = P9_PORT;
172         opts->sq_depth = P9_RDMA_SQ_DEPTH;
173         opts->rq_depth = P9_RDMA_RQ_DEPTH;
174         opts->timeout = P9_RDMA_TIMEOUT;
175
176         if (!params)
177                 return 0;
178
179         options = kstrdup(params, GFP_KERNEL);
180         if (!options) {
181                 P9_DPRINTK(P9_DEBUG_ERROR,
182                            "failed to allocate copy of option string\n");
183                 return -ENOMEM;
184         }
185
186         while ((p = strsep(&options, ",")) != NULL) {
187                 int token;
188                 int r;
189                 if (!*p)
190                         continue;
191                 token = match_token(p, tokens, args);
192                 r = match_int(&args[0], &option);
193                 if (r < 0) {
194                         P9_DPRINTK(P9_DEBUG_ERROR,
195                                    "integer field, but no integer?\n");
196                         ret = r;
197                         continue;
198                 }
199                 switch (token) {
200                 case Opt_port:
201                         opts->port = option;
202                         break;
203                 case Opt_sq_depth:
204                         opts->sq_depth = option;
205                         break;
206                 case Opt_rq_depth:
207                         opts->rq_depth = option;
208                         break;
209                 case Opt_timeout:
210                         opts->timeout = option;
211                         break;
212                 default:
213                         continue;
214                 }
215         }
216         /* RQ must be at least as large as the SQ */
217         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
218         kfree(options);
219         return 0;
220 }
221
222 static int
223 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
224 {
225         struct p9_client *c = id->context;
226         struct p9_trans_rdma *rdma = c->trans;
227         switch (event->event) {
228         case RDMA_CM_EVENT_ADDR_RESOLVED:
229                 BUG_ON(rdma->state != P9_RDMA_INIT);
230                 rdma->state = P9_RDMA_ADDR_RESOLVED;
231                 break;
232
233         case RDMA_CM_EVENT_ROUTE_RESOLVED:
234                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
235                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
236                 break;
237
238         case RDMA_CM_EVENT_ESTABLISHED:
239                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
240                 rdma->state = P9_RDMA_CONNECTED;
241                 break;
242
243         case RDMA_CM_EVENT_DISCONNECTED:
244                 if (rdma)
245                         rdma->state = P9_RDMA_CLOSED;
246                 if (c)
247                         c->status = Disconnected;
248                 break;
249
250         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
251                 break;
252
253         case RDMA_CM_EVENT_ADDR_CHANGE:
254         case RDMA_CM_EVENT_ROUTE_ERROR:
255         case RDMA_CM_EVENT_DEVICE_REMOVAL:
256         case RDMA_CM_EVENT_MULTICAST_JOIN:
257         case RDMA_CM_EVENT_MULTICAST_ERROR:
258         case RDMA_CM_EVENT_REJECTED:
259         case RDMA_CM_EVENT_CONNECT_REQUEST:
260         case RDMA_CM_EVENT_CONNECT_RESPONSE:
261         case RDMA_CM_EVENT_CONNECT_ERROR:
262         case RDMA_CM_EVENT_ADDR_ERROR:
263         case RDMA_CM_EVENT_UNREACHABLE:
264                 c->status = Disconnected;
265                 rdma_disconnect(rdma->cm_id);
266                 break;
267         default:
268                 BUG();
269         }
270         complete(&rdma->cm_done);
271         return 0;
272 }
273
274 static void
275 handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
276             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
277 {
278         struct p9_req_t *req;
279         int err = 0;
280         int16_t tag;
281
282         req = NULL;
283         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
284                                                          DMA_FROM_DEVICE);
285
286         if (status != IB_WC_SUCCESS)
287                 goto err_out;
288
289         err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
290         if (err)
291                 goto err_out;
292
293         req = p9_tag_lookup(client, tag);
294         if (!req)
295                 goto err_out;
296
297         req->rc = c->rc;
298         p9_client_cb(client, req);
299
300         return;
301
302  err_out:
303         P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
304                    req, err, status);
305         rdma->state = P9_RDMA_FLUSHING;
306         client->status = Disconnected;
307         return;
308 }
309
310 static void
311 handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
312             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
313 {
314         ib_dma_unmap_single(rdma->cm_id->device,
315                             c->busa, c->req->tc->size,
316                             DMA_TO_DEVICE);
317 }
318
319 static void qp_event_handler(struct ib_event *event, void *context)
320 {
321         P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n", event->event,
322                                                                 context);
323 }
324
325 static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
326 {
327         struct p9_client *client = cq_context;
328         struct p9_trans_rdma *rdma = client->trans;
329         int ret;
330         struct ib_wc wc;
331
332         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
333         while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
334                 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
335
336                 switch (c->wc_op) {
337                 case IB_WC_RECV:
338                         atomic_dec(&rdma->rq_count);
339                         handle_recv(client, rdma, c, wc.status, wc.byte_len);
340                         break;
341
342                 case IB_WC_SEND:
343                         handle_send(client, rdma, c, wc.status, wc.byte_len);
344                         up(&rdma->sq_sem);
345                         break;
346
347                 default:
348                         printk(KERN_ERR "9prdma: unexpected completion type, "
349                                "c->wc_op=%d, wc.opcode=%d, status=%d\n",
350                                c->wc_op, wc.opcode, wc.status);
351                         break;
352                 }
353                 kfree(c);
354         }
355 }
356
357 static void cq_event_handler(struct ib_event *e, void *v)
358 {
359         P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
360 }
361
362 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
363 {
364         if (!rdma)
365                 return;
366
367         if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
368                 ib_dereg_mr(rdma->dma_mr);
369
370         if (rdma->qp && !IS_ERR(rdma->qp))
371                 ib_destroy_qp(rdma->qp);
372
373         if (rdma->pd && !IS_ERR(rdma->pd))
374                 ib_dealloc_pd(rdma->pd);
375
376         if (rdma->cq && !IS_ERR(rdma->cq))
377                 ib_destroy_cq(rdma->cq);
378
379         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
380                 rdma_destroy_id(rdma->cm_id);
381
382         kfree(rdma);
383 }
384
385 static int
386 post_recv(struct p9_client *client, struct p9_rdma_context *c)
387 {
388         struct p9_trans_rdma *rdma = client->trans;
389         struct ib_recv_wr wr, *bad_wr;
390         struct ib_sge sge;
391
392         c->busa = ib_dma_map_single(rdma->cm_id->device,
393                                     c->rc->sdata, client->msize,
394                                     DMA_FROM_DEVICE);
395         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
396                 goto error;
397
398         sge.addr = c->busa;
399         sge.length = client->msize;
400         sge.lkey = rdma->lkey;
401
402         wr.next = NULL;
403         c->wc_op = IB_WC_RECV;
404         wr.wr_id = (unsigned long) c;
405         wr.sg_list = &sge;
406         wr.num_sge = 1;
407         return ib_post_recv(rdma->qp, &wr, &bad_wr);
408
409  error:
410         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
411         return -EIO;
412 }
413
414 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
415 {
416         struct p9_trans_rdma *rdma = client->trans;
417         struct ib_send_wr wr, *bad_wr;
418         struct ib_sge sge;
419         int err = 0;
420         unsigned long flags;
421         struct p9_rdma_context *c = NULL;
422         struct p9_rdma_context *rpl_context = NULL;
423
424         /* Allocate an fcall for the reply */
425         rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
426         if (!rpl_context)
427                 goto err_close;
428
429         /*
430          * If the request has a buffer, steal it, otherwise
431          * allocate a new one.  Typically, requests should already
432          * have receive buffers allocated and just swap them around
433          */
434         if (!req->rc) {
435                 req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
436                                                                 GFP_KERNEL);
437                 if (req->rc) {
438                         req->rc->sdata = (char *) req->rc +
439                                                 sizeof(struct p9_fcall);
440                         req->rc->capacity = client->msize;
441                 }
442         }
443         rpl_context->rc = req->rc;
444         if (!rpl_context->rc) {
445                 kfree(rpl_context);
446                 goto err_close;
447         }
448
449         /*
450          * Post a receive buffer for this request. We need to ensure
451          * there is a reply buffer available for every outstanding
452          * request. A flushed request can result in no reply for an
453          * outstanding request, so we must keep a count to avoid
454          * overflowing the RQ.
455          */
456         if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
457                 err = post_recv(client, rpl_context);
458                 if (err) {
459                         kfree(rpl_context->rc);
460                         kfree(rpl_context);
461                         goto err_close;
462                 }
463         } else
464                 atomic_dec(&rdma->rq_count);
465
466         /* remove posted receive buffer from request structure */
467         req->rc = NULL;
468
469         /* Post the request */
470         c = kmalloc(sizeof *c, GFP_KERNEL);
471         if (!c)
472                 goto err_close;
473         c->req = req;
474
475         c->busa = ib_dma_map_single(rdma->cm_id->device,
476                                     c->req->tc->sdata, c->req->tc->size,
477                                     DMA_TO_DEVICE);
478         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
479                 goto error;
480
481         sge.addr = c->busa;
482         sge.length = c->req->tc->size;
483         sge.lkey = rdma->lkey;
484
485         wr.next = NULL;
486         c->wc_op = IB_WC_SEND;
487         wr.wr_id = (unsigned long) c;
488         wr.opcode = IB_WR_SEND;
489         wr.send_flags = IB_SEND_SIGNALED;
490         wr.sg_list = &sge;
491         wr.num_sge = 1;
492
493         if (down_interruptible(&rdma->sq_sem))
494                 goto error;
495
496         return ib_post_send(rdma->qp, &wr, &bad_wr);
497
498  error:
499         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
500         return -EIO;
501
502  err_close:
503         spin_lock_irqsave(&rdma->req_lock, flags);
504         if (rdma->state < P9_RDMA_CLOSING) {
505                 rdma->state = P9_RDMA_CLOSING;
506                 spin_unlock_irqrestore(&rdma->req_lock, flags);
507                 rdma_disconnect(rdma->cm_id);
508         } else
509                 spin_unlock_irqrestore(&rdma->req_lock, flags);
510         return err;
511 }
512
513 static void rdma_close(struct p9_client *client)
514 {
515         struct p9_trans_rdma *rdma;
516
517         if (!client)
518                 return;
519
520         rdma = client->trans;
521         if (!rdma)
522                 return;
523
524         client->status = Disconnected;
525         rdma_disconnect(rdma->cm_id);
526         rdma_destroy_trans(rdma);
527 }
528
529 /**
530  * alloc_rdma - Allocate and initialize the rdma transport structure
531  * @opts: Mount options structure
532  */
533 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
534 {
535         struct p9_trans_rdma *rdma;
536
537         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
538         if (!rdma)
539                 return NULL;
540
541         rdma->sq_depth = opts->sq_depth;
542         rdma->rq_depth = opts->rq_depth;
543         rdma->timeout = opts->timeout;
544         spin_lock_init(&rdma->req_lock);
545         init_completion(&rdma->cm_done);
546         sema_init(&rdma->sq_sem, rdma->sq_depth);
547         atomic_set(&rdma->rq_count, 0);
548
549         return rdma;
550 }
551
552 /* its not clear to me we can do anything after send has been posted */
553 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
554 {
555         return 1;
556 }
557
558 /**
559  * trans_create_rdma - Transport method for creating atransport instance
560  * @client: client instance
561  * @addr: IP address string
562  * @args: Mount options string
563  */
564 static int
565 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
566 {
567         int err;
568         struct p9_rdma_opts opts;
569         struct p9_trans_rdma *rdma;
570         struct rdma_conn_param conn_param;
571         struct ib_qp_init_attr qp_attr;
572         struct ib_device_attr devattr;
573
574         /* Parse the transport specific mount options */
575         err = parse_opts(args, &opts);
576         if (err < 0)
577                 return err;
578
579         /* Create and initialize the RDMA transport structure */
580         rdma = alloc_rdma(&opts);
581         if (!rdma)
582                 return -ENOMEM;
583
584         /* Create the RDMA CM ID */
585         rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP);
586         if (IS_ERR(rdma->cm_id))
587                 goto error;
588
589         /* Associate the client with the transport */
590         client->trans = rdma;
591
592         /* Resolve the server's address */
593         rdma->addr.sin_family = AF_INET;
594         rdma->addr.sin_addr.s_addr = in_aton(addr);
595         rdma->addr.sin_port = htons(opts.port);
596         err = rdma_resolve_addr(rdma->cm_id, NULL,
597                                 (struct sockaddr *)&rdma->addr,
598                                 rdma->timeout);
599         if (err)
600                 goto error;
601         err = wait_for_completion_interruptible(&rdma->cm_done);
602         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
603                 goto error;
604
605         /* Resolve the route to the server */
606         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
607         if (err)
608                 goto error;
609         err = wait_for_completion_interruptible(&rdma->cm_done);
610         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
611                 goto error;
612
613         /* Query the device attributes */
614         err = ib_query_device(rdma->cm_id->device, &devattr);
615         if (err)
616                 goto error;
617
618         /* Create the Completion Queue */
619         rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
620                                 cq_event_handler, client,
621                                 opts.sq_depth + opts.rq_depth + 1, 0);
622         if (IS_ERR(rdma->cq))
623                 goto error;
624         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
625
626         /* Create the Protection Domain */
627         rdma->pd = ib_alloc_pd(rdma->cm_id->device);
628         if (IS_ERR(rdma->pd))
629                 goto error;
630
631         /* Cache the DMA lkey in the transport */
632         rdma->dma_mr = NULL;
633         if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
634                 rdma->lkey = rdma->cm_id->device->local_dma_lkey;
635         else {
636                 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
637                 if (IS_ERR(rdma->dma_mr))
638                         goto error;
639                 rdma->lkey = rdma->dma_mr->lkey;
640         }
641
642         /* Create the Queue Pair */
643         memset(&qp_attr, 0, sizeof qp_attr);
644         qp_attr.event_handler = qp_event_handler;
645         qp_attr.qp_context = client;
646         qp_attr.cap.max_send_wr = opts.sq_depth;
647         qp_attr.cap.max_recv_wr = opts.rq_depth;
648         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
649         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
650         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
651         qp_attr.qp_type = IB_QPT_RC;
652         qp_attr.send_cq = rdma->cq;
653         qp_attr.recv_cq = rdma->cq;
654         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
655         if (err)
656                 goto error;
657         rdma->qp = rdma->cm_id->qp;
658
659         /* Request a connection */
660         memset(&conn_param, 0, sizeof(conn_param));
661         conn_param.private_data = NULL;
662         conn_param.private_data_len = 0;
663         conn_param.responder_resources = P9_RDMA_IRD;
664         conn_param.initiator_depth = P9_RDMA_ORD;
665         err = rdma_connect(rdma->cm_id, &conn_param);
666         if (err)
667                 goto error;
668         err = wait_for_completion_interruptible(&rdma->cm_done);
669         if (err || (rdma->state != P9_RDMA_CONNECTED))
670                 goto error;
671
672         client->status = Connected;
673
674         return 0;
675
676 error:
677         rdma_destroy_trans(rdma);
678         return -ENOTCONN;
679 }
680
681 static struct p9_trans_module p9_rdma_trans = {
682         .name = "rdma",
683         .maxsize = P9_RDMA_MAXSIZE,
684         .def = 0,
685         .owner = THIS_MODULE,
686         .create = rdma_create_trans,
687         .close = rdma_close,
688         .request = rdma_request,
689         .cancel = rdma_cancel,
690 };
691
692 /**
693  * p9_trans_rdma_init - Register the 9P RDMA transport driver
694  */
695 static int __init p9_trans_rdma_init(void)
696 {
697         v9fs_register_trans(&p9_rdma_trans);
698         return 0;
699 }
700
701 static void __exit p9_trans_rdma_exit(void)
702 {
703         v9fs_unregister_trans(&p9_rdma_trans);
704 }
705
706 module_init(p9_trans_rdma_init);
707 module_exit(p9_trans_rdma_exit);
708
709 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
710 MODULE_DESCRIPTION("RDMA Transport for 9P");
711 MODULE_LICENSE("Dual BSD/GPL");