9p: rdma: Set trans prior to requesting async connection ops
[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 #include <rdma/ib_verbs.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  * @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  * @addr: The remote peer's address
77  * @req_lock: Protects the active request list
78  * @send_wait: Wait list when the SQ fills up
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_options - parse mount options into session structure
159  * @options: options string passed from mount
160  * @opts: 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;
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         options = kstrdup(params, GFP_KERNEL);
181         if (!options) {
182                 P9_DPRINTK(P9_DEBUG_ERROR,
183                            "failed to allocate copy of option string\n");
184                 return -ENOMEM;
185         }
186
187         while ((p = strsep(&options, ",")) != NULL) {
188                 int token;
189                 int r;
190                 if (!*p)
191                         continue;
192                 token = match_token(p, tokens, args);
193                 r = match_int(&args[0], &option);
194                 if (r < 0) {
195                         P9_DPRINTK(P9_DEBUG_ERROR,
196                                    "integer field, but no integer?\n");
197                         ret = r;
198                         continue;
199                 }
200                 switch (token) {
201                 case Opt_port:
202                         opts->port = option;
203                         break;
204                 case Opt_sq_depth:
205                         opts->sq_depth = option;
206                         break;
207                 case Opt_rq_depth:
208                         opts->rq_depth = option;
209                         break;
210                 case Opt_timeout:
211                         opts->timeout = option;
212                         break;
213                 default:
214                         continue;
215                 }
216         }
217         /* RQ must be at least as large as the SQ */
218         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
219         kfree(options);
220         return 0;
221 }
222
223 static int
224 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
225 {
226         struct p9_client *c = id->context;
227         struct p9_trans_rdma *rdma = c->trans;
228         switch (event->event) {
229         case RDMA_CM_EVENT_ADDR_RESOLVED:
230                 BUG_ON(rdma->state != P9_RDMA_INIT);
231                 rdma->state = P9_RDMA_ADDR_RESOLVED;
232                 break;
233
234         case RDMA_CM_EVENT_ROUTE_RESOLVED:
235                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
236                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
237                 break;
238
239         case RDMA_CM_EVENT_ESTABLISHED:
240                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
241                 rdma->state = P9_RDMA_CONNECTED;
242                 break;
243
244         case RDMA_CM_EVENT_DISCONNECTED:
245                 if (rdma)
246                         rdma->state = P9_RDMA_CLOSED;
247                 if (c)
248                         c->status = Disconnected;
249                 break;
250
251         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
252                 break;
253
254         case RDMA_CM_EVENT_ADDR_CHANGE:
255         case RDMA_CM_EVENT_ROUTE_ERROR:
256         case RDMA_CM_EVENT_DEVICE_REMOVAL:
257         case RDMA_CM_EVENT_MULTICAST_JOIN:
258         case RDMA_CM_EVENT_MULTICAST_ERROR:
259         case RDMA_CM_EVENT_REJECTED:
260         case RDMA_CM_EVENT_CONNECT_REQUEST:
261         case RDMA_CM_EVENT_CONNECT_RESPONSE:
262         case RDMA_CM_EVENT_CONNECT_ERROR:
263         case RDMA_CM_EVENT_ADDR_ERROR:
264         case RDMA_CM_EVENT_UNREACHABLE:
265                 c->status = Disconnected;
266                 rdma_disconnect(rdma->cm_id);
267                 break;
268         default:
269                 BUG();
270         }
271         complete(&rdma->cm_done);
272         return 0;
273 }
274
275 static void
276 handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
277             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
278 {
279         struct p9_req_t *req;
280         int err = 0;
281         int16_t tag;
282
283         req = NULL;
284         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
285                                                          DMA_FROM_DEVICE);
286
287         if (status != IB_WC_SUCCESS)
288                 goto err_out;
289
290         err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
291         if (err)
292                 goto err_out;
293
294         req = p9_tag_lookup(client, tag);
295         if (!req)
296                 goto err_out;
297
298         req->rc = c->rc;
299         p9_client_cb(client, req);
300
301         return;
302
303  err_out:
304         P9_DPRINTK(P9_DEBUG_ERROR, "req %p err %d status %d\n",
305                    req, err, status);
306         rdma->state = P9_RDMA_FLUSHING;
307         client->status = Disconnected;
308         return;
309 }
310
311 static void
312 handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
313             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
314 {
315         ib_dma_unmap_single(rdma->cm_id->device,
316                             c->busa, c->req->tc->size,
317                             DMA_TO_DEVICE);
318 }
319
320 static void qp_event_handler(struct ib_event *event, void *context)
321 {
322         P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n", event->event,
323                                                                 context);
324 }
325
326 static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
327 {
328         struct p9_client *client = cq_context;
329         struct p9_trans_rdma *rdma = client->trans;
330         int ret;
331         struct ib_wc wc;
332
333         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
334         while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
335                 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
336
337                 switch (c->wc_op) {
338                 case IB_WC_RECV:
339                         atomic_dec(&rdma->rq_count);
340                         handle_recv(client, rdma, c, wc.status, wc.byte_len);
341                         break;
342
343                 case IB_WC_SEND:
344                         handle_send(client, rdma, c, wc.status, wc.byte_len);
345                         up(&rdma->sq_sem);
346                         break;
347
348                 default:
349                         printk(KERN_ERR "9prdma: unexpected completion type, "
350                                "c->wc_op=%d, wc.opcode=%d, status=%d\n",
351                                c->wc_op, wc.opcode, wc.status);
352                         break;
353                 }
354                 kfree(c);
355         }
356 }
357
358 static void cq_event_handler(struct ib_event *e, void *v)
359 {
360         P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
361 }
362
363 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
364 {
365         if (!rdma)
366                 return;
367
368         if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
369                 ib_dereg_mr(rdma->dma_mr);
370
371         if (rdma->qp && !IS_ERR(rdma->qp))
372                 ib_destroy_qp(rdma->qp);
373
374         if (rdma->pd && !IS_ERR(rdma->pd))
375                 ib_dealloc_pd(rdma->pd);
376
377         if (rdma->cq && !IS_ERR(rdma->cq))
378                 ib_destroy_cq(rdma->cq);
379
380         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
381                 rdma_destroy_id(rdma->cm_id);
382
383         kfree(rdma);
384 }
385
386 static int
387 post_recv(struct p9_client *client, struct p9_rdma_context *c)
388 {
389         struct p9_trans_rdma *rdma = client->trans;
390         struct ib_recv_wr wr, *bad_wr;
391         struct ib_sge sge;
392
393         c->busa = ib_dma_map_single(rdma->cm_id->device,
394                                     c->rc->sdata, client->msize,
395                                     DMA_FROM_DEVICE);
396         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
397                 goto error;
398
399         sge.addr = c->busa;
400         sge.length = client->msize;
401         sge.lkey = rdma->lkey;
402
403         wr.next = NULL;
404         c->wc_op = IB_WC_RECV;
405         wr.wr_id = (unsigned long) c;
406         wr.sg_list = &sge;
407         wr.num_sge = 1;
408         return ib_post_recv(rdma->qp, &wr, &bad_wr);
409
410  error:
411         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
412         return -EIO;
413 }
414
415 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
416 {
417         struct p9_trans_rdma *rdma = client->trans;
418         struct ib_send_wr wr, *bad_wr;
419         struct ib_sge sge;
420         int err = 0;
421         unsigned long flags;
422         struct p9_rdma_context *c = NULL;
423         struct p9_rdma_context *rpl_context = NULL;
424
425         /* Allocate an fcall for the reply */
426         rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
427         if (!rpl_context)
428                 goto err_close;
429
430         /*
431          * If the request has a buffer, steal it, otherwise
432          * allocate a new one.  Typically, requests should already
433          * have receive buffers allocated and just swap them around
434          */
435         if (!req->rc) {
436                 req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
437                                                                 GFP_KERNEL);
438                 if (req->rc) {
439                         req->rc->sdata = (char *) req->rc +
440                                                 sizeof(struct p9_fcall);
441                         req->rc->capacity = client->msize;
442                 }
443         }
444         rpl_context->rc = req->rc;
445         if (!rpl_context->rc) {
446                 kfree(rpl_context);
447                 goto err_close;
448         }
449
450         /*
451          * Post a receive buffer for this request. We need to ensure
452          * there is a reply buffer available for every outstanding
453          * request. A flushed request can result in no reply for an
454          * outstanding request, so we must keep a count to avoid
455          * overflowing the RQ.
456          */
457         if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
458                 err = post_recv(client, rpl_context);
459                 if (err) {
460                         kfree(rpl_context->rc);
461                         kfree(rpl_context);
462                         goto err_close;
463                 }
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_KERNEL);
472         if (!c)
473                 goto err_close;
474         c->req = req;
475
476         c->busa = ib_dma_map_single(rdma->cm_id->device,
477                                     c->req->tc->sdata, c->req->tc->size,
478                                     DMA_TO_DEVICE);
479         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
480                 goto error;
481
482         sge.addr = c->busa;
483         sge.length = c->req->tc->size;
484         sge.lkey = rdma->lkey;
485
486         wr.next = NULL;
487         c->wc_op = IB_WC_SEND;
488         wr.wr_id = (unsigned long) c;
489         wr.opcode = IB_WR_SEND;
490         wr.send_flags = IB_SEND_SIGNALED;
491         wr.sg_list = &sge;
492         wr.num_sge = 1;
493
494         if (down_interruptible(&rdma->sq_sem))
495                 goto error;
496
497         return ib_post_send(rdma->qp, &wr, &bad_wr);
498
499  error:
500         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
501         return -EIO;
502
503  err_close:
504         spin_lock_irqsave(&rdma->req_lock, flags);
505         if (rdma->state < P9_RDMA_CLOSING) {
506                 rdma->state = P9_RDMA_CLOSING;
507                 spin_unlock_irqrestore(&rdma->req_lock, flags);
508                 rdma_disconnect(rdma->cm_id);
509         } else
510                 spin_unlock_irqrestore(&rdma->req_lock, flags);
511         return err;
512 }
513
514 static void rdma_close(struct p9_client *client)
515 {
516         struct p9_trans_rdma *rdma;
517
518         if (!client)
519                 return;
520
521         rdma = client->trans;
522         if (!rdma)
523                 return;
524
525         client->status = Disconnected;
526         rdma_disconnect(rdma->cm_id);
527         rdma_destroy_trans(rdma);
528 }
529
530 /**
531  * alloc_rdma - Allocate and initialize the rdma transport structure
532  * @msize: MTU
533  * @dotu: Extension attribute
534  * @opts: Mount options structure
535  */
536 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
537 {
538         struct p9_trans_rdma *rdma;
539
540         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
541         if (!rdma)
542                 return NULL;
543
544         rdma->sq_depth = opts->sq_depth;
545         rdma->rq_depth = opts->rq_depth;
546         rdma->timeout = opts->timeout;
547         spin_lock_init(&rdma->req_lock);
548         init_completion(&rdma->cm_done);
549         sema_init(&rdma->sq_sem, rdma->sq_depth);
550         atomic_set(&rdma->rq_count, 0);
551
552         return rdma;
553 }
554
555 /* its not clear to me we can do anything after send has been posted */
556 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
557 {
558         return 1;
559 }
560
561 /**
562  * trans_create_rdma - Transport method for creating atransport instance
563  * @client: client instance
564  * @addr: IP address string
565  * @args: Mount options string
566  */
567 static int
568 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
569 {
570         int err;
571         struct p9_rdma_opts opts;
572         struct p9_trans_rdma *rdma;
573         struct rdma_conn_param conn_param;
574         struct ib_qp_init_attr qp_attr;
575         struct ib_device_attr devattr;
576
577         /* Parse the transport specific mount options */
578         err = parse_opts(args, &opts);
579         if (err < 0)
580                 return err;
581
582         /* Create and initialize the RDMA transport structure */
583         rdma = alloc_rdma(&opts);
584         if (!rdma)
585                 return -ENOMEM;
586
587         /* Create the RDMA CM ID */
588         rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP);
589         if (IS_ERR(rdma->cm_id))
590                 goto error;
591
592         /* Associate the client with the transport */
593         client->trans = rdma;
594
595         /* Resolve the server's address */
596         rdma->addr.sin_family = AF_INET;
597         rdma->addr.sin_addr.s_addr = in_aton(addr);
598         rdma->addr.sin_port = htons(opts.port);
599         err = rdma_resolve_addr(rdma->cm_id, NULL,
600                                 (struct sockaddr *)&rdma->addr,
601                                 rdma->timeout);
602         if (err)
603                 goto error;
604         err = wait_for_completion_interruptible(&rdma->cm_done);
605         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
606                 goto error;
607
608         /* Resolve the route to the server */
609         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
610         if (err)
611                 goto error;
612         err = wait_for_completion_interruptible(&rdma->cm_done);
613         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
614                 goto error;
615
616         /* Query the device attributes */
617         err = ib_query_device(rdma->cm_id->device, &devattr);
618         if (err)
619                 goto error;
620
621         /* Create the Completion Queue */
622         rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
623                                 cq_event_handler, client,
624                                 opts.sq_depth + opts.rq_depth + 1, 0);
625         if (IS_ERR(rdma->cq))
626                 goto error;
627         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
628
629         /* Create the Protection Domain */
630         rdma->pd = ib_alloc_pd(rdma->cm_id->device);
631         if (IS_ERR(rdma->pd))
632                 goto error;
633
634         /* Cache the DMA lkey in the transport */
635         rdma->dma_mr = NULL;
636         if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
637                 rdma->lkey = rdma->cm_id->device->local_dma_lkey;
638         else {
639                 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE);
640                 if (IS_ERR(rdma->dma_mr))
641                         goto error;
642                 rdma->lkey = rdma->dma_mr->lkey;
643         }
644
645         /* Create the Queue Pair */
646         memset(&qp_attr, 0, sizeof qp_attr);
647         qp_attr.event_handler = qp_event_handler;
648         qp_attr.qp_context = client;
649         qp_attr.cap.max_send_wr = opts.sq_depth;
650         qp_attr.cap.max_recv_wr = opts.rq_depth;
651         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
652         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
653         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
654         qp_attr.qp_type = IB_QPT_RC;
655         qp_attr.send_cq = rdma->cq;
656         qp_attr.recv_cq = rdma->cq;
657         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
658         if (err)
659                 goto error;
660         rdma->qp = rdma->cm_id->qp;
661
662         /* Request a connection */
663         memset(&conn_param, 0, sizeof(conn_param));
664         conn_param.private_data = NULL;
665         conn_param.private_data_len = 0;
666         conn_param.responder_resources = P9_RDMA_IRD;
667         conn_param.initiator_depth = P9_RDMA_ORD;
668         err = rdma_connect(rdma->cm_id, &conn_param);
669         if (err)
670                 goto error;
671         err = wait_for_completion_interruptible(&rdma->cm_done);
672         if (err || (rdma->state != P9_RDMA_CONNECTED))
673                 goto error;
674
675         client->status = Connected;
676
677         return 0;
678
679 error:
680         rdma_destroy_trans(rdma);
681         return -ENOTCONN;
682 }
683
684 static struct p9_trans_module p9_rdma_trans = {
685         .name = "rdma",
686         .maxsize = P9_RDMA_MAXSIZE,
687         .def = 0,
688         .owner = THIS_MODULE,
689         .create = rdma_create_trans,
690         .close = rdma_close,
691         .request = rdma_request,
692         .cancel = rdma_cancel,
693 };
694
695 /**
696  * p9_trans_rdma_init - Register the 9P RDMA transport driver
697  */
698 static int __init p9_trans_rdma_init(void)
699 {
700         v9fs_register_trans(&p9_rdma_trans);
701         return 0;
702 }
703
704 static void __exit p9_trans_rdma_exit(void)
705 {
706         v9fs_unregister_trans(&p9_rdma_trans);
707 }
708
709 module_init(p9_trans_rdma_init);
710 module_exit(p9_trans_rdma_exit);
711
712 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
713 MODULE_DESCRIPTION("RDMA Transport for 9P");
714 MODULE_LICENSE("Dual BSD/GPL");