041101ab4aa55b6ceec057e40c007ae57ff409ba
[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 #define P9_RDMA_MAX_SGE (P9_RDMA_MAXSIZE >> PAGE_SHIFT)
63 /**
64  * struct p9_trans_rdma - RDMA transport instance
65  *
66  * @state: tracks the transport state machine for connection setup and tear down
67  * @cm_id: The RDMA CM ID
68  * @pd: Protection Domain pointer
69  * @qp: Queue Pair pointer
70  * @cq: Completion Queue pointer
71  * @dm_mr: DMA Memory Region pointer
72  * @lkey: The local access only memory region key
73  * @timeout: Number of uSecs to wait for connection management events
74  * @sq_depth: The depth of the Send Queue
75  * @sq_sem: Semaphore for the SQ
76  * @rq_depth: The depth of the Receive Queue.
77  * @rq_count: Count of requests in the Receive Queue.
78  * @addr: The remote peer's address
79  * @req_lock: Protects the active request list
80  * @cm_done: Completion event for connection management tracking
81  */
82 struct p9_trans_rdma {
83         enum {
84                 P9_RDMA_INIT,
85                 P9_RDMA_ADDR_RESOLVED,
86                 P9_RDMA_ROUTE_RESOLVED,
87                 P9_RDMA_CONNECTED,
88                 P9_RDMA_FLUSHING,
89                 P9_RDMA_CLOSING,
90                 P9_RDMA_CLOSED,
91         } state;
92         struct rdma_cm_id *cm_id;
93         struct ib_pd *pd;
94         struct ib_qp *qp;
95         struct ib_cq *cq;
96         struct ib_mr *dma_mr;
97         u32 lkey;
98         long timeout;
99         int sq_depth;
100         struct semaphore sq_sem;
101         int rq_depth;
102         atomic_t rq_count;
103         struct sockaddr_in addr;
104         spinlock_t req_lock;
105
106         struct completion cm_done;
107 };
108
109 /**
110  * p9_rdma_context - Keeps track of in-process WR
111  *
112  * @wc_op: The original WR op for when the CQE completes in error.
113  * @busa: Bus address to unmap when the WR completes
114  * @req: Keeps track of requests (send)
115  * @rc: Keepts track of replies (receive)
116  */
117 struct p9_rdma_req;
118 struct p9_rdma_context {
119         enum ib_wc_opcode wc_op;
120         dma_addr_t busa;
121         union {
122                 struct p9_req_t *req;
123                 struct p9_fcall *rc;
124         };
125 };
126
127 /**
128  * p9_rdma_opts - Collection of mount options
129  * @port: port of connection
130  * @sq_depth: The requested depth of the SQ. This really doesn't need
131  * to be any deeper than the number of threads used in the client
132  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
133  * @timeout: Time to wait in msecs for CM events
134  */
135 struct p9_rdma_opts {
136         short port;
137         int sq_depth;
138         int rq_depth;
139         long timeout;
140 };
141
142 /*
143  * Option Parsing (code inspired by NFS code)
144  */
145 enum {
146         /* Options that take integer arguments */
147         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, Opt_err,
148 };
149
150 static match_table_t tokens = {
151         {Opt_port, "port=%u"},
152         {Opt_sq_depth, "sq=%u"},
153         {Opt_rq_depth, "rq=%u"},
154         {Opt_timeout, "timeout=%u"},
155         {Opt_err, NULL},
156 };
157
158 /**
159  * parse_opts - parse mount options into rdma options structure
160  * @params: options string passed from mount
161  * @opts: rdma transport-specific structure to parse options into
162  *
163  * Returns 0 upon success, -ERRNO upon failure
164  */
165 static int parse_opts(char *params, struct p9_rdma_opts *opts)
166 {
167         char *p;
168         substring_t args[MAX_OPT_ARGS];
169         int option;
170         char *options, *tmp_options;
171         int ret;
172
173         opts->port = P9_PORT;
174         opts->sq_depth = P9_RDMA_SQ_DEPTH;
175         opts->rq_depth = P9_RDMA_RQ_DEPTH;
176         opts->timeout = P9_RDMA_TIMEOUT;
177
178         if (!params)
179                 return 0;
180
181         tmp_options = kstrdup(params, GFP_KERNEL);
182         if (!tmp_options) {
183                 P9_DPRINTK(P9_DEBUG_ERROR,
184                            "failed to allocate copy of option string\n");
185                 return -ENOMEM;
186         }
187         options = tmp_options;
188
189         while ((p = strsep(&options, ",")) != NULL) {
190                 int token;
191                 int r;
192                 if (!*p)
193                         continue;
194                 token = match_token(p, tokens, args);
195                 r = match_int(&args[0], &option);
196                 if (r < 0) {
197                         P9_DPRINTK(P9_DEBUG_ERROR,
198                                    "integer field, but no integer?\n");
199                         ret = r;
200                         continue;
201                 }
202                 switch (token) {
203                 case Opt_port:
204                         opts->port = option;
205                         break;
206                 case Opt_sq_depth:
207                         opts->sq_depth = option;
208                         break;
209                 case Opt_rq_depth:
210                         opts->rq_depth = option;
211                         break;
212                 case Opt_timeout:
213                         opts->timeout = option;
214                         break;
215                 default:
216                         continue;
217                 }
218         }
219         /* RQ must be at least as large as the SQ */
220         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
221         kfree(tmp_options);
222         return 0;
223 }
224
225 static int
226 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
227 {
228         struct p9_client *c = id->context;
229         struct p9_trans_rdma *rdma = c->trans;
230         switch (event->event) {
231         case RDMA_CM_EVENT_ADDR_RESOLVED:
232                 BUG_ON(rdma->state != P9_RDMA_INIT);
233                 rdma->state = P9_RDMA_ADDR_RESOLVED;
234                 break;
235
236         case RDMA_CM_EVENT_ROUTE_RESOLVED:
237                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
238                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
239                 break;
240
241         case RDMA_CM_EVENT_ESTABLISHED:
242                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
243                 rdma->state = P9_RDMA_CONNECTED;
244                 break;
245
246         case RDMA_CM_EVENT_DISCONNECTED:
247                 if (rdma)
248                         rdma->state = P9_RDMA_CLOSED;
249                 if (c)
250                         c->status = Disconnected;
251                 break;
252
253         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
254                 break;
255
256         case RDMA_CM_EVENT_ADDR_CHANGE:
257         case RDMA_CM_EVENT_ROUTE_ERROR:
258         case RDMA_CM_EVENT_DEVICE_REMOVAL:
259         case RDMA_CM_EVENT_MULTICAST_JOIN:
260         case RDMA_CM_EVENT_MULTICAST_ERROR:
261         case RDMA_CM_EVENT_REJECTED:
262         case RDMA_CM_EVENT_CONNECT_REQUEST:
263         case RDMA_CM_EVENT_CONNECT_RESPONSE:
264         case RDMA_CM_EVENT_CONNECT_ERROR:
265         case RDMA_CM_EVENT_ADDR_ERROR:
266         case RDMA_CM_EVENT_UNREACHABLE:
267                 c->status = Disconnected;
268                 rdma_disconnect(rdma->cm_id);
269                 break;
270         default:
271                 BUG();
272         }
273         complete(&rdma->cm_done);
274         return 0;
275 }
276
277 static void
278 handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
279             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
280 {
281         struct p9_req_t *req;
282         int err = 0;
283         int16_t tag;
284
285         req = NULL;
286         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
287                                                          DMA_FROM_DEVICE);
288
289         if (status != IB_WC_SUCCESS)
290                 goto err_out;
291
292         err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
293         if (err)
294                 goto err_out;
295
296         req = p9_tag_lookup(client, tag);
297         if (!req)
298                 goto err_out;
299
300         req->rc = c->rc;
301         req->status = REQ_STATUS_RCVD;
302         p9_client_cb(client, req);
303
304         return;
305
306  err_out:
307         P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
308                    req, err, status);
309         rdma->state = P9_RDMA_FLUSHING;
310         client->status = Disconnected;
311         return;
312 }
313
314 static void
315 handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
316             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
317 {
318         ib_dma_unmap_single(rdma->cm_id->device,
319                             c->busa, c->req->tc->size,
320                             DMA_TO_DEVICE);
321 }
322
323 static void qp_event_handler(struct ib_event *event, void *context)
324 {
325         P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n", event->event,
326                                                                 context);
327 }
328
329 static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
330 {
331         struct p9_client *client = cq_context;
332         struct p9_trans_rdma *rdma = client->trans;
333         int ret;
334         struct ib_wc wc;
335
336         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
337         while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
338                 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
339
340                 switch (c->wc_op) {
341                 case IB_WC_RECV:
342                         atomic_dec(&rdma->rq_count);
343                         handle_recv(client, rdma, c, wc.status, wc.byte_len);
344                         break;
345
346                 case IB_WC_SEND:
347                         handle_send(client, rdma, c, wc.status, wc.byte_len);
348                         up(&rdma->sq_sem);
349                         break;
350
351                 default:
352                         printk(KERN_ERR "9prdma: unexpected completion type, "
353                                "c->wc_op=%d, wc.opcode=%d, status=%d\n",
354                                c->wc_op, wc.opcode, wc.status);
355                         break;
356                 }
357                 kfree(c);
358         }
359 }
360
361 static void cq_event_handler(struct ib_event *e, void *v)
362 {
363         P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
364 }
365
366 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
367 {
368         if (!rdma)
369                 return;
370
371         if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
372                 ib_dereg_mr(rdma->dma_mr);
373
374         if (rdma->qp && !IS_ERR(rdma->qp))
375                 ib_destroy_qp(rdma->qp);
376
377         if (rdma->pd && !IS_ERR(rdma->pd))
378                 ib_dealloc_pd(rdma->pd);
379
380         if (rdma->cq && !IS_ERR(rdma->cq))
381                 ib_destroy_cq(rdma->cq);
382
383         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
384                 rdma_destroy_id(rdma->cm_id);
385
386         kfree(rdma);
387 }
388
389 static int
390 post_recv(struct p9_client *client, struct p9_rdma_context *c)
391 {
392         struct p9_trans_rdma *rdma = client->trans;
393         struct ib_recv_wr wr, *bad_wr;
394         struct ib_sge sge;
395
396         c->busa = ib_dma_map_single(rdma->cm_id->device,
397                                     c->rc->sdata, client->msize,
398                                     DMA_FROM_DEVICE);
399         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
400                 goto error;
401
402         sge.addr = c->busa;
403         sge.length = client->msize;
404         sge.lkey = rdma->lkey;
405
406         wr.next = NULL;
407         c->wc_op = IB_WC_RECV;
408         wr.wr_id = (unsigned long) c;
409         wr.sg_list = &sge;
410         wr.num_sge = 1;
411         return ib_post_recv(rdma->qp, &wr, &bad_wr);
412
413  error:
414         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
415         return -EIO;
416 }
417
418 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
419 {
420         struct p9_trans_rdma *rdma = client->trans;
421         struct ib_send_wr wr, *bad_wr;
422         struct ib_sge sge;
423         int err = 0;
424         unsigned long flags;
425         struct p9_rdma_context *c = NULL;
426         struct p9_rdma_context *rpl_context = NULL;
427
428         /* Allocate an fcall for the reply */
429         rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
430         if (!rpl_context)
431                 goto err_close;
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_KERNEL);
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                 kfree(rpl_context);
450                 goto err_close;
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                         kfree(rpl_context->rc);
464                         kfree(rpl_context);
465                         goto err_close;
466                 }
467         } else
468                 atomic_dec(&rdma->rq_count);
469
470         /* remove posted receive buffer from request structure */
471         req->rc = NULL;
472
473         /* Post the request */
474         c = kmalloc(sizeof *c, GFP_KERNEL);
475         if (!c)
476                 goto err_close;
477         c->req = req;
478
479         c->busa = ib_dma_map_single(rdma->cm_id->device,
480                                     c->req->tc->sdata, c->req->tc->size,
481                                     DMA_TO_DEVICE);
482         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
483                 goto error;
484
485         sge.addr = c->busa;
486         sge.length = c->req->tc->size;
487         sge.lkey = rdma->lkey;
488
489         wr.next = NULL;
490         c->wc_op = IB_WC_SEND;
491         wr.wr_id = (unsigned long) c;
492         wr.opcode = IB_WR_SEND;
493         wr.send_flags = IB_SEND_SIGNALED;
494         wr.sg_list = &sge;
495         wr.num_sge = 1;
496
497         if (down_interruptible(&rdma->sq_sem))
498                 goto error;
499
500         return ib_post_send(rdma->qp, &wr, &bad_wr);
501
502  error:
503         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
504         return -EIO;
505
506  err_close:
507         spin_lock_irqsave(&rdma->req_lock, flags);
508         if (rdma->state < P9_RDMA_CLOSING) {
509                 rdma->state = P9_RDMA_CLOSING;
510                 spin_unlock_irqrestore(&rdma->req_lock, flags);
511                 rdma_disconnect(rdma->cm_id);
512         } else
513                 spin_unlock_irqrestore(&rdma->req_lock, flags);
514         return err;
515 }
516
517 static void rdma_close(struct p9_client *client)
518 {
519         struct p9_trans_rdma *rdma;
520
521         if (!client)
522                 return;
523
524         rdma = client->trans;
525         if (!rdma)
526                 return;
527
528         client->status = Disconnected;
529         rdma_disconnect(rdma->cm_id);
530         rdma_destroy_trans(rdma);
531 }
532
533 /**
534  * alloc_rdma - Allocate and initialize the rdma transport structure
535  * @opts: Mount options structure
536  */
537 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
538 {
539         struct p9_trans_rdma *rdma;
540
541         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
542         if (!rdma)
543                 return NULL;
544
545         rdma->sq_depth = opts->sq_depth;
546         rdma->rq_depth = opts->rq_depth;
547         rdma->timeout = opts->timeout;
548         spin_lock_init(&rdma->req_lock);
549         init_completion(&rdma->cm_done);
550         sema_init(&rdma->sq_sem, rdma->sq_depth);
551         atomic_set(&rdma->rq_count, 0);
552
553         return rdma;
554 }
555
556 /* its not clear to me we can do anything after send has been posted */
557 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
558 {
559         return 1;
560 }
561
562 /**
563  * trans_create_rdma - Transport method for creating atransport instance
564  * @client: client instance
565  * @addr: IP address string
566  * @args: Mount options string
567  */
568 static int
569 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
570 {
571         int err;
572         struct p9_rdma_opts opts;
573         struct p9_trans_rdma *rdma;
574         struct rdma_conn_param conn_param;
575         struct ib_qp_init_attr qp_attr;
576         struct ib_device_attr devattr;
577
578         /* Parse the transport specific mount options */
579         err = parse_opts(args, &opts);
580         if (err < 0)
581                 return err;
582
583         /* Create and initialize the RDMA transport structure */
584         rdma = alloc_rdma(&opts);
585         if (!rdma)
586                 return -ENOMEM;
587
588         /* Create the RDMA CM ID */
589         rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP);
590         if (IS_ERR(rdma->cm_id))
591                 goto error;
592
593         /* Associate the client with the transport */
594         client->trans = rdma;
595
596         /* Resolve the server's address */
597         rdma->addr.sin_family = AF_INET;
598         rdma->addr.sin_addr.s_addr = in_aton(addr);
599         rdma->addr.sin_port = htons(opts.port);
600         err = rdma_resolve_addr(rdma->cm_id, NULL,
601                                 (struct sockaddr *)&rdma->addr,
602                                 rdma->timeout);
603         if (err)
604                 goto error;
605         err = wait_for_completion_interruptible(&rdma->cm_done);
606         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
607                 goto error;
608
609         /* Resolve the route to the server */
610         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
611         if (err)
612                 goto error;
613         err = wait_for_completion_interruptible(&rdma->cm_done);
614         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
615                 goto error;
616
617         /* Query the device attributes */
618         err = ib_query_device(rdma->cm_id->device, &devattr);
619         if (err)
620                 goto error;
621
622         /* Create the Completion Queue */
623         rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
624                                 cq_event_handler, client,
625                                 opts.sq_depth + opts.rq_depth + 1, 0);
626         if (IS_ERR(rdma->cq))
627                 goto error;
628         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
629
630         /* Create the Protection Domain */
631         rdma->pd = ib_alloc_pd(rdma->cm_id->device);
632         if (IS_ERR(rdma->pd))
633                 goto error;
634
635         /* Cache the DMA lkey in the transport */
636         rdma->dma_mr = NULL;
637         if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
638                 rdma->lkey = rdma->cm_id->device->local_dma_lkey;
639         else {
640                 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
641                 if (IS_ERR(rdma->dma_mr))
642                         goto error;
643                 rdma->lkey = rdma->dma_mr->lkey;
644         }
645
646         /* Create the Queue Pair */
647         memset(&qp_attr, 0, sizeof qp_attr);
648         qp_attr.event_handler = qp_event_handler;
649         qp_attr.qp_context = client;
650         qp_attr.cap.max_send_wr = opts.sq_depth;
651         qp_attr.cap.max_recv_wr = opts.rq_depth;
652         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
653         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
654         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
655         qp_attr.qp_type = IB_QPT_RC;
656         qp_attr.send_cq = rdma->cq;
657         qp_attr.recv_cq = rdma->cq;
658         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
659         if (err)
660                 goto error;
661         rdma->qp = rdma->cm_id->qp;
662
663         /* Request a connection */
664         memset(&conn_param, 0, sizeof(conn_param));
665         conn_param.private_data = NULL;
666         conn_param.private_data_len = 0;
667         conn_param.responder_resources = P9_RDMA_IRD;
668         conn_param.initiator_depth = P9_RDMA_ORD;
669         err = rdma_connect(rdma->cm_id, &conn_param);
670         if (err)
671                 goto error;
672         err = wait_for_completion_interruptible(&rdma->cm_done);
673         if (err || (rdma->state != P9_RDMA_CONNECTED))
674                 goto error;
675
676         client->status = Connected;
677
678         return 0;
679
680 error:
681         rdma_destroy_trans(rdma);
682         return -ENOTCONN;
683 }
684
685 static struct p9_trans_module p9_rdma_trans = {
686         .name = "rdma",
687         .maxsize = P9_RDMA_MAXSIZE,
688         .def = 0,
689         .owner = THIS_MODULE,
690         .create = rdma_create_trans,
691         .close = rdma_close,
692         .request = rdma_request,
693         .cancel = rdma_cancel,
694 };
695
696 /**
697  * p9_trans_rdma_init - Register the 9P RDMA transport driver
698  */
699 static int __init p9_trans_rdma_init(void)
700 {
701         v9fs_register_trans(&p9_rdma_trans);
702         return 0;
703 }
704
705 static void __exit p9_trans_rdma_exit(void)
706 {
707         v9fs_unregister_trans(&p9_rdma_trans);
708 }
709
710 module_init(p9_trans_rdma_init);
711 module_exit(p9_trans_rdma_exit);
712
713 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
714 MODULE_DESCRIPTION("RDMA Transport for 9P");
715 MODULE_LICENSE("Dual BSD/GPL");