RDMA/cma: Pass QP type into rdma_create_id()
[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 <linux/slab.h>
44 #include <net/9p/9p.h>
45 #include <net/9p/client.h>
46 #include <net/9p/transport.h>
47 #include <rdma/ib_verbs.h>
48 #include <rdma/rdma_cm.h>
49
50 #define P9_PORT                 5640
51 #define P9_RDMA_SQ_DEPTH        32
52 #define P9_RDMA_RQ_DEPTH        32
53 #define P9_RDMA_SEND_SGE        4
54 #define P9_RDMA_RECV_SGE        4
55 #define P9_RDMA_IRD             0
56 #define P9_RDMA_ORD             0
57 #define P9_RDMA_TIMEOUT         30000           /* 30 seconds */
58 #define P9_RDMA_MAXSIZE         (4*4096)        /* Min SGE is 4, so we can
59                                                  * safely advertise a maxsize
60                                                  * of 64k */
61
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  * @dm_mr: DMA Memory Region pointer
71  * @lkey: The local access only memory region key
72  * @timeout: Number of uSecs to wait for connection management events
73  * @sq_depth: The depth of the Send Queue
74  * @sq_sem: Semaphore for the SQ
75  * @rq_depth: The depth of the Receive Queue.
76  * @rq_count: Count of requests in the Receive Queue.
77  * @addr: The remote peer's address
78  * @req_lock: Protects the active request list
79  * @cm_done: Completion event for connection management tracking
80  */
81 struct p9_trans_rdma {
82         enum {
83                 P9_RDMA_INIT,
84                 P9_RDMA_ADDR_RESOLVED,
85                 P9_RDMA_ROUTE_RESOLVED,
86                 P9_RDMA_CONNECTED,
87                 P9_RDMA_FLUSHING,
88                 P9_RDMA_CLOSING,
89                 P9_RDMA_CLOSED,
90         } state;
91         struct rdma_cm_id *cm_id;
92         struct ib_pd *pd;
93         struct ib_qp *qp;
94         struct ib_cq *cq;
95         struct ib_mr *dma_mr;
96         u32 lkey;
97         long timeout;
98         int sq_depth;
99         struct semaphore sq_sem;
100         int rq_depth;
101         atomic_t rq_count;
102         struct sockaddr_in addr;
103         spinlock_t req_lock;
104
105         struct completion cm_done;
106 };
107
108 /**
109  * p9_rdma_context - Keeps track of in-process WR
110  *
111  * @wc_op: The original WR op for when the CQE completes in error.
112  * @busa: Bus address to unmap when the WR completes
113  * @req: Keeps track of requests (send)
114  * @rc: Keepts track of replies (receive)
115  */
116 struct p9_rdma_req;
117 struct p9_rdma_context {
118         enum ib_wc_opcode wc_op;
119         dma_addr_t busa;
120         union {
121                 struct p9_req_t *req;
122                 struct p9_fcall *rc;
123         };
124 };
125
126 /**
127  * p9_rdma_opts - Collection of mount options
128  * @port: port of connection
129  * @sq_depth: The requested depth of the SQ. This really doesn't need
130  * to be any deeper than the number of threads used in the client
131  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
132  * @timeout: Time to wait in msecs for CM events
133  */
134 struct p9_rdma_opts {
135         short port;
136         int sq_depth;
137         int rq_depth;
138         long timeout;
139 };
140
141 /*
142  * Option Parsing (code inspired by NFS code)
143  */
144 enum {
145         /* Options that take integer arguments */
146         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
147 };
148
149 static match_table_t tokens = {
150         {Opt_port, "port=%u"},
151         {Opt_sq_depth, "sq=%u"},
152         {Opt_rq_depth, "rq=%u"},
153         {Opt_timeout, "timeout=%u"},
154         {Opt_err, NULL},
155 };
156
157 /**
158  * parse_opts - parse mount options into rdma options structure
159  * @params: options string passed from mount
160  * @opts: rdma transport-specific structure to parse options into
161  *
162  * Returns 0 upon success, -ERRNO upon failure
163  */
164 static int parse_opts(char *params, struct p9_rdma_opts *opts)
165 {
166         char *p;
167         substring_t args[MAX_OPT_ARGS];
168         int option;
169         char *options, *tmp_options;
170         int ret;
171
172         opts->port = P9_PORT;
173         opts->sq_depth = P9_RDMA_SQ_DEPTH;
174         opts->rq_depth = P9_RDMA_RQ_DEPTH;
175         opts->timeout = P9_RDMA_TIMEOUT;
176
177         if (!params)
178                 return 0;
179
180         tmp_options = kstrdup(params, GFP_KERNEL);
181         if (!tmp_options) {
182                 P9_DPRINTK(P9_DEBUG_ERROR,
183                            "failed to allocate copy of option string\n");
184                 return -ENOMEM;
185         }
186         options = tmp_options;
187
188         while ((p = strsep(&options, ",")) != NULL) {
189                 int token;
190                 int r;
191                 if (!*p)
192                         continue;
193                 token = match_token(p, tokens, args);
194                 r = match_int(&args[0], &option);
195                 if (r < 0) {
196                         P9_DPRINTK(P9_DEBUG_ERROR,
197                                    "integer field, but no integer?\n");
198                         ret = r;
199                         continue;
200                 }
201                 switch (token) {
202                 case Opt_port:
203                         opts->port = option;
204                         break;
205                 case Opt_sq_depth:
206                         opts->sq_depth = option;
207                         break;
208                 case Opt_rq_depth:
209                         opts->rq_depth = option;
210                         break;
211                 case Opt_timeout:
212                         opts->timeout = option;
213                         break;
214                 default:
215                         continue;
216                 }
217         }
218         /* RQ must be at least as large as the SQ */
219         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
220         kfree(tmp_options);
221         return 0;
222 }
223
224 static int
225 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
226 {
227         struct p9_client *c = id->context;
228         struct p9_trans_rdma *rdma = c->trans;
229         switch (event->event) {
230         case RDMA_CM_EVENT_ADDR_RESOLVED:
231                 BUG_ON(rdma->state != P9_RDMA_INIT);
232                 rdma->state = P9_RDMA_ADDR_RESOLVED;
233                 break;
234
235         case RDMA_CM_EVENT_ROUTE_RESOLVED:
236                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
237                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
238                 break;
239
240         case RDMA_CM_EVENT_ESTABLISHED:
241                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
242                 rdma->state = P9_RDMA_CONNECTED;
243                 break;
244
245         case RDMA_CM_EVENT_DISCONNECTED:
246                 if (rdma)
247                         rdma->state = P9_RDMA_CLOSED;
248                 if (c)
249                         c->status = Disconnected;
250                 break;
251
252         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
253                 break;
254
255         case RDMA_CM_EVENT_ADDR_CHANGE:
256         case RDMA_CM_EVENT_ROUTE_ERROR:
257         case RDMA_CM_EVENT_DEVICE_REMOVAL:
258         case RDMA_CM_EVENT_MULTICAST_JOIN:
259         case RDMA_CM_EVENT_MULTICAST_ERROR:
260         case RDMA_CM_EVENT_REJECTED:
261         case RDMA_CM_EVENT_CONNECT_REQUEST:
262         case RDMA_CM_EVENT_CONNECT_RESPONSE:
263         case RDMA_CM_EVENT_CONNECT_ERROR:
264         case RDMA_CM_EVENT_ADDR_ERROR:
265         case RDMA_CM_EVENT_UNREACHABLE:
266                 c->status = Disconnected;
267                 rdma_disconnect(rdma->cm_id);
268                 break;
269         default:
270                 BUG();
271         }
272         complete(&rdma->cm_done);
273         return 0;
274 }
275
276 static void
277 handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
278             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
279 {
280         struct p9_req_t *req;
281         int err = 0;
282         int16_t tag;
283
284         req = NULL;
285         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
286                                                          DMA_FROM_DEVICE);
287
288         if (status != IB_WC_SUCCESS)
289                 goto err_out;
290
291         err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
292         if (err)
293                 goto err_out;
294
295         req = p9_tag_lookup(client, tag);
296         if (!req)
297                 goto err_out;
298
299         req->rc = c->rc;
300         req->status = REQ_STATUS_RCVD;
301         p9_client_cb(client, req);
302
303         return;
304
305  err_out:
306         P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
307                    req, err, status);
308         rdma->state = P9_RDMA_FLUSHING;
309         client->status = Disconnected;
310 }
311
312 static void
313 handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
314             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
315 {
316         ib_dma_unmap_single(rdma->cm_id->device,
317                             c->busa, c->req->tc->size,
318                             DMA_TO_DEVICE);
319 }
320
321 static void qp_event_handler(struct ib_event *event, void *context)
322 {
323         P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n", event->event,
324                                                                 context);
325 }
326
327 static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
328 {
329         struct p9_client *client = cq_context;
330         struct p9_trans_rdma *rdma = client->trans;
331         int ret;
332         struct ib_wc wc;
333
334         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
335         while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
336                 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
337
338                 switch (c->wc_op) {
339                 case IB_WC_RECV:
340                         atomic_dec(&rdma->rq_count);
341                         handle_recv(client, rdma, c, wc.status, wc.byte_len);
342                         break;
343
344                 case IB_WC_SEND:
345                         handle_send(client, rdma, c, wc.status, wc.byte_len);
346                         up(&rdma->sq_sem);
347                         break;
348
349                 default:
350                         printk(KERN_ERR "9prdma: unexpected completion type, "
351                                "c->wc_op=%d, wc.opcode=%d, status=%d\n",
352                                c->wc_op, wc.opcode, wc.status);
353                         break;
354                 }
355                 kfree(c);
356         }
357 }
358
359 static void cq_event_handler(struct ib_event *e, void *v)
360 {
361         P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
362 }
363
364 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
365 {
366         if (!rdma)
367                 return;
368
369         if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
370                 ib_dereg_mr(rdma->dma_mr);
371
372         if (rdma->qp && !IS_ERR(rdma->qp))
373                 ib_destroy_qp(rdma->qp);
374
375         if (rdma->pd && !IS_ERR(rdma->pd))
376                 ib_dealloc_pd(rdma->pd);
377
378         if (rdma->cq && !IS_ERR(rdma->cq))
379                 ib_destroy_cq(rdma->cq);
380
381         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
382                 rdma_destroy_id(rdma->cm_id);
383
384         kfree(rdma);
385 }
386
387 static int
388 post_recv(struct p9_client *client, struct p9_rdma_context *c)
389 {
390         struct p9_trans_rdma *rdma = client->trans;
391         struct ib_recv_wr wr, *bad_wr;
392         struct ib_sge sge;
393
394         c->busa = ib_dma_map_single(rdma->cm_id->device,
395                                     c->rc->sdata, client->msize,
396                                     DMA_FROM_DEVICE);
397         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
398                 goto error;
399
400         sge.addr = c->busa;
401         sge.length = client->msize;
402         sge.lkey = rdma->lkey;
403
404         wr.next = NULL;
405         c->wc_op = IB_WC_RECV;
406         wr.wr_id = (unsigned long) c;
407         wr.sg_list = &sge;
408         wr.num_sge = 1;
409         return ib_post_recv(rdma->qp, &wr, &bad_wr);
410
411  error:
412         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
413         return -EIO;
414 }
415
416 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
417 {
418         struct p9_trans_rdma *rdma = client->trans;
419         struct ib_send_wr wr, *bad_wr;
420         struct ib_sge sge;
421         int err = 0;
422         unsigned long flags;
423         struct p9_rdma_context *c = NULL;
424         struct p9_rdma_context *rpl_context = NULL;
425
426         /* Allocate an fcall for the reply */
427         rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
428         if (!rpl_context) {
429                 err = -ENOMEM;
430                 goto err_close;
431         }
432
433         /*
434          * If the request has a buffer, steal it, otherwise
435          * allocate a new one.  Typically, requests should already
436          * have receive buffers allocated and just swap them around
437          */
438         if (!req->rc) {
439                 req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
440                                   GFP_NOFS);
441                 if (req->rc) {
442                         req->rc->sdata = (char *) req->rc +
443                                                 sizeof(struct p9_fcall);
444                         req->rc->capacity = client->msize;
445                 }
446         }
447         rpl_context->rc = req->rc;
448         if (!rpl_context->rc) {
449                 err = -ENOMEM;
450                 goto err_free2;
451         }
452
453         /*
454          * Post a receive buffer for this request. We need to ensure
455          * there is a reply buffer available for every outstanding
456          * request. A flushed request can result in no reply for an
457          * outstanding request, so we must keep a count to avoid
458          * overflowing the RQ.
459          */
460         if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
461                 err = post_recv(client, rpl_context);
462                 if (err)
463                         goto err_free1;
464         } else
465                 atomic_dec(&rdma->rq_count);
466
467         /* remove posted receive buffer from request structure */
468         req->rc = NULL;
469
470         /* Post the request */
471         c = kmalloc(sizeof *c, GFP_NOFS);
472         if (!c) {
473                 err = -ENOMEM;
474                 goto err_free1;
475         }
476         c->req = req;
477
478         c->busa = ib_dma_map_single(rdma->cm_id->device,
479                                     c->req->tc->sdata, c->req->tc->size,
480                                     DMA_TO_DEVICE);
481         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
482                 goto error;
483
484         sge.addr = c->busa;
485         sge.length = c->req->tc->size;
486         sge.lkey = rdma->lkey;
487
488         wr.next = NULL;
489         c->wc_op = IB_WC_SEND;
490         wr.wr_id = (unsigned long) c;
491         wr.opcode = IB_WR_SEND;
492         wr.send_flags = IB_SEND_SIGNALED;
493         wr.sg_list = &sge;
494         wr.num_sge = 1;
495
496         if (down_interruptible(&rdma->sq_sem))
497                 goto error;
498
499         return ib_post_send(rdma->qp, &wr, &bad_wr);
500
501  error:
502         kfree(c);
503         kfree(rpl_context->rc);
504         kfree(rpl_context);
505         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
506         return -EIO;
507  err_free1:
508         kfree(rpl_context->rc);
509  err_free2:
510         kfree(rpl_context);
511  err_close:
512         spin_lock_irqsave(&rdma->req_lock, flags);
513         if (rdma->state < P9_RDMA_CLOSING) {
514                 rdma->state = P9_RDMA_CLOSING;
515                 spin_unlock_irqrestore(&rdma->req_lock, flags);
516                 rdma_disconnect(rdma->cm_id);
517         } else
518                 spin_unlock_irqrestore(&rdma->req_lock, flags);
519         return err;
520 }
521
522 static void rdma_close(struct p9_client *client)
523 {
524         struct p9_trans_rdma *rdma;
525
526         if (!client)
527                 return;
528
529         rdma = client->trans;
530         if (!rdma)
531                 return;
532
533         client->status = Disconnected;
534         rdma_disconnect(rdma->cm_id);
535         rdma_destroy_trans(rdma);
536 }
537
538 /**
539  * alloc_rdma - Allocate and initialize the rdma transport structure
540  * @opts: Mount options structure
541  */
542 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
543 {
544         struct p9_trans_rdma *rdma;
545
546         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
547         if (!rdma)
548                 return NULL;
549
550         rdma->sq_depth = opts->sq_depth;
551         rdma->rq_depth = opts->rq_depth;
552         rdma->timeout = opts->timeout;
553         spin_lock_init(&rdma->req_lock);
554         init_completion(&rdma->cm_done);
555         sema_init(&rdma->sq_sem, rdma->sq_depth);
556         atomic_set(&rdma->rq_count, 0);
557
558         return rdma;
559 }
560
561 /* its not clear to me we can do anything after send has been posted */
562 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
563 {
564         return 1;
565 }
566
567 /**
568  * trans_create_rdma - Transport method for creating atransport instance
569  * @client: client instance
570  * @addr: IP address string
571  * @args: Mount options string
572  */
573 static int
574 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
575 {
576         int err;
577         struct p9_rdma_opts opts;
578         struct p9_trans_rdma *rdma;
579         struct rdma_conn_param conn_param;
580         struct ib_qp_init_attr qp_attr;
581         struct ib_device_attr devattr;
582
583         /* Parse the transport specific mount options */
584         err = parse_opts(args, &opts);
585         if (err < 0)
586                 return err;
587
588         /* Create and initialize the RDMA transport structure */
589         rdma = alloc_rdma(&opts);
590         if (!rdma)
591                 return -ENOMEM;
592
593         /* Create the RDMA CM ID */
594         rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP,
595                                      IB_QPT_RC);
596         if (IS_ERR(rdma->cm_id))
597                 goto error;
598
599         /* Associate the client with the transport */
600         client->trans = rdma;
601
602         /* Resolve the server's address */
603         rdma->addr.sin_family = AF_INET;
604         rdma->addr.sin_addr.s_addr = in_aton(addr);
605         rdma->addr.sin_port = htons(opts.port);
606         err = rdma_resolve_addr(rdma->cm_id, NULL,
607                                 (struct sockaddr *)&rdma->addr,
608                                 rdma->timeout);
609         if (err)
610                 goto error;
611         err = wait_for_completion_interruptible(&rdma->cm_done);
612         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
613                 goto error;
614
615         /* Resolve the route to the server */
616         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
617         if (err)
618                 goto error;
619         err = wait_for_completion_interruptible(&rdma->cm_done);
620         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
621                 goto error;
622
623         /* Query the device attributes */
624         err = ib_query_device(rdma->cm_id->device, &devattr);
625         if (err)
626                 goto error;
627
628         /* Create the Completion Queue */
629         rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
630                                 cq_event_handler, client,
631                                 opts.sq_depth + opts.rq_depth + 1, 0);
632         if (IS_ERR(rdma->cq))
633                 goto error;
634         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
635
636         /* Create the Protection Domain */
637         rdma->pd = ib_alloc_pd(rdma->cm_id->device);
638         if (IS_ERR(rdma->pd))
639                 goto error;
640
641         /* Cache the DMA lkey in the transport */
642         rdma->dma_mr = NULL;
643         if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
644                 rdma->lkey = rdma->cm_id->device->local_dma_lkey;
645         else {
646                 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
647                 if (IS_ERR(rdma->dma_mr))
648                         goto error;
649                 rdma->lkey = rdma->dma_mr->lkey;
650         }
651
652         /* Create the Queue Pair */
653         memset(&qp_attr, 0, sizeof qp_attr);
654         qp_attr.event_handler = qp_event_handler;
655         qp_attr.qp_context = client;
656         qp_attr.cap.max_send_wr = opts.sq_depth;
657         qp_attr.cap.max_recv_wr = opts.rq_depth;
658         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
659         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
660         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
661         qp_attr.qp_type = IB_QPT_RC;
662         qp_attr.send_cq = rdma->cq;
663         qp_attr.recv_cq = rdma->cq;
664         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
665         if (err)
666                 goto error;
667         rdma->qp = rdma->cm_id->qp;
668
669         /* Request a connection */
670         memset(&conn_param, 0, sizeof(conn_param));
671         conn_param.private_data = NULL;
672         conn_param.private_data_len = 0;
673         conn_param.responder_resources = P9_RDMA_IRD;
674         conn_param.initiator_depth = P9_RDMA_ORD;
675         err = rdma_connect(rdma->cm_id, &conn_param);
676         if (err)
677                 goto error;
678         err = wait_for_completion_interruptible(&rdma->cm_done);
679         if (err || (rdma->state != P9_RDMA_CONNECTED))
680                 goto error;
681
682         client->status = Connected;
683
684         return 0;
685
686 error:
687         rdma_destroy_trans(rdma);
688         return -ENOTCONN;
689 }
690
691 static struct p9_trans_module p9_rdma_trans = {
692         .name = "rdma",
693         .maxsize = P9_RDMA_MAXSIZE,
694         .def = 0,
695         .owner = THIS_MODULE,
696         .create = rdma_create_trans,
697         .close = rdma_close,
698         .request = rdma_request,
699         .cancel = rdma_cancel,
700 };
701
702 /**
703  * p9_trans_rdma_init - Register the 9P RDMA transport driver
704  */
705 static int __init p9_trans_rdma_init(void)
706 {
707         v9fs_register_trans(&p9_rdma_trans);
708         return 0;
709 }
710
711 static void __exit p9_trans_rdma_exit(void)
712 {
713         v9fs_unregister_trans(&p9_rdma_trans);
714 }
715
716 module_init(p9_trans_rdma_init);
717 module_exit(p9_trans_rdma_exit);
718
719 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
720 MODULE_DESCRIPTION("RDMA Transport for 9P");
721 MODULE_LICENSE("Dual BSD/GPL");