net/9p: Return error if we fail to encode protocol data
[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 }
312
313 static void
314 handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
315             struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
316 {
317         ib_dma_unmap_single(rdma->cm_id->device,
318                             c->busa, c->req->tc->size,
319                             DMA_TO_DEVICE);
320 }
321
322 static void qp_event_handler(struct ib_event *event, void *context)
323 {
324         P9_DPRINTK(P9_DEBUG_ERROR, "QP event %d context %p\n", event->event,
325                                                                 context);
326 }
327
328 static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
329 {
330         struct p9_client *client = cq_context;
331         struct p9_trans_rdma *rdma = client->trans;
332         int ret;
333         struct ib_wc wc;
334
335         ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
336         while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
337                 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
338
339                 switch (c->wc_op) {
340                 case IB_WC_RECV:
341                         atomic_dec(&rdma->rq_count);
342                         handle_recv(client, rdma, c, wc.status, wc.byte_len);
343                         break;
344
345                 case IB_WC_SEND:
346                         handle_send(client, rdma, c, wc.status, wc.byte_len);
347                         up(&rdma->sq_sem);
348                         break;
349
350                 default:
351                         printk(KERN_ERR "9prdma: unexpected completion type, "
352                                "c->wc_op=%d, wc.opcode=%d, status=%d\n",
353                                c->wc_op, wc.opcode, wc.status);
354                         break;
355                 }
356                 kfree(c);
357         }
358 }
359
360 static void cq_event_handler(struct ib_event *e, void *v)
361 {
362         P9_DPRINTK(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
363 }
364
365 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
366 {
367         if (!rdma)
368                 return;
369
370         if (rdma->dma_mr && !IS_ERR(rdma->dma_mr))
371                 ib_dereg_mr(rdma->dma_mr);
372
373         if (rdma->qp && !IS_ERR(rdma->qp))
374                 ib_destroy_qp(rdma->qp);
375
376         if (rdma->pd && !IS_ERR(rdma->pd))
377                 ib_dealloc_pd(rdma->pd);
378
379         if (rdma->cq && !IS_ERR(rdma->cq))
380                 ib_destroy_cq(rdma->cq);
381
382         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
383                 rdma_destroy_id(rdma->cm_id);
384
385         kfree(rdma);
386 }
387
388 static int
389 post_recv(struct p9_client *client, struct p9_rdma_context *c)
390 {
391         struct p9_trans_rdma *rdma = client->trans;
392         struct ib_recv_wr wr, *bad_wr;
393         struct ib_sge sge;
394
395         c->busa = ib_dma_map_single(rdma->cm_id->device,
396                                     c->rc->sdata, client->msize,
397                                     DMA_FROM_DEVICE);
398         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
399                 goto error;
400
401         sge.addr = c->busa;
402         sge.length = client->msize;
403         sge.lkey = rdma->lkey;
404
405         wr.next = NULL;
406         c->wc_op = IB_WC_RECV;
407         wr.wr_id = (unsigned long) c;
408         wr.sg_list = &sge;
409         wr.num_sge = 1;
410         return ib_post_recv(rdma->qp, &wr, &bad_wr);
411
412  error:
413         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
414         return -EIO;
415 }
416
417 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
418 {
419         struct p9_trans_rdma *rdma = client->trans;
420         struct ib_send_wr wr, *bad_wr;
421         struct ib_sge sge;
422         int err = 0;
423         unsigned long flags;
424         struct p9_rdma_context *c = NULL;
425         struct p9_rdma_context *rpl_context = NULL;
426
427         /* Allocate an fcall for the reply */
428         rpl_context = kmalloc(sizeof *rpl_context, GFP_KERNEL);
429         if (!rpl_context) {
430                 err = -ENOMEM;
431                 goto err_close;
432         }
433
434         /*
435          * If the request has a buffer, steal it, otherwise
436          * allocate a new one.  Typically, requests should already
437          * have receive buffers allocated and just swap them around
438          */
439         if (!req->rc) {
440                 req->rc = kmalloc(sizeof(struct p9_fcall)+client->msize,
441                                                                 GFP_KERNEL);
442                 if (req->rc) {
443                         req->rc->sdata = (char *) req->rc +
444                                                 sizeof(struct p9_fcall);
445                         req->rc->capacity = client->msize;
446                 }
447         }
448         rpl_context->rc = req->rc;
449         if (!rpl_context->rc) {
450                 err = -ENOMEM;
451                 goto err_free2;
452         }
453
454         /*
455          * Post a receive buffer for this request. We need to ensure
456          * there is a reply buffer available for every outstanding
457          * request. A flushed request can result in no reply for an
458          * outstanding request, so we must keep a count to avoid
459          * overflowing the RQ.
460          */
461         if (atomic_inc_return(&rdma->rq_count) <= rdma->rq_depth) {
462                 err = post_recv(client, rpl_context);
463                 if (err)
464                         goto err_free1;
465         } else
466                 atomic_dec(&rdma->rq_count);
467
468         /* remove posted receive buffer from request structure */
469         req->rc = NULL;
470
471         /* Post the request */
472         c = kmalloc(sizeof *c, GFP_KERNEL);
473         if (!c) {
474                 err = -ENOMEM;
475                 goto err_free1;
476         }
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         kfree(c);
504         kfree(rpl_context->rc);
505         kfree(rpl_context);
506         P9_DPRINTK(P9_DEBUG_ERROR, "EIO\n");
507         return -EIO;
508  err_free1:
509         kfree(rpl_context->rc);
510  err_free2:
511         kfree(rpl_context);
512  err_close:
513         spin_lock_irqsave(&rdma->req_lock, flags);
514         if (rdma->state < P9_RDMA_CLOSING) {
515                 rdma->state = P9_RDMA_CLOSING;
516                 spin_unlock_irqrestore(&rdma->req_lock, flags);
517                 rdma_disconnect(rdma->cm_id);
518         } else
519                 spin_unlock_irqrestore(&rdma->req_lock, flags);
520         return err;
521 }
522
523 static void rdma_close(struct p9_client *client)
524 {
525         struct p9_trans_rdma *rdma;
526
527         if (!client)
528                 return;
529
530         rdma = client->trans;
531         if (!rdma)
532                 return;
533
534         client->status = Disconnected;
535         rdma_disconnect(rdma->cm_id);
536         rdma_destroy_trans(rdma);
537 }
538
539 /**
540  * alloc_rdma - Allocate and initialize the rdma transport structure
541  * @opts: Mount options structure
542  */
543 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
544 {
545         struct p9_trans_rdma *rdma;
546
547         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
548         if (!rdma)
549                 return NULL;
550
551         rdma->sq_depth = opts->sq_depth;
552         rdma->rq_depth = opts->rq_depth;
553         rdma->timeout = opts->timeout;
554         spin_lock_init(&rdma->req_lock);
555         init_completion(&rdma->cm_done);
556         sema_init(&rdma->sq_sem, rdma->sq_depth);
557         atomic_set(&rdma->rq_count, 0);
558
559         return rdma;
560 }
561
562 /* its not clear to me we can do anything after send has been posted */
563 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
564 {
565         return 1;
566 }
567
568 /**
569  * trans_create_rdma - Transport method for creating atransport instance
570  * @client: client instance
571  * @addr: IP address string
572  * @args: Mount options string
573  */
574 static int
575 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
576 {
577         int err;
578         struct p9_rdma_opts opts;
579         struct p9_trans_rdma *rdma;
580         struct rdma_conn_param conn_param;
581         struct ib_qp_init_attr qp_attr;
582         struct ib_device_attr devattr;
583
584         /* Parse the transport specific mount options */
585         err = parse_opts(args, &opts);
586         if (err < 0)
587                 return err;
588
589         /* Create and initialize the RDMA transport structure */
590         rdma = alloc_rdma(&opts);
591         if (!rdma)
592                 return -ENOMEM;
593
594         /* Create the RDMA CM ID */
595         rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP);
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");