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TOMOYO Linux Cross Reference
Linux/net/9p/trans_rdma.c

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  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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 30 
 31 #include <linux/in.h>
 32 #include <linux/module.h>
 33 #include <linux/net.h>
 34 #include <linux/ipv6.h>
 35 #include <linux/kthread.h>
 36 #include <linux/errno.h>
 37 #include <linux/kernel.h>
 38 #include <linux/un.h>
 39 #include <linux/uaccess.h>
 40 #include <linux/inet.h>
 41 #include <linux/idr.h>
 42 #include <linux/file.h>
 43 #include <linux/parser.h>
 44 #include <linux/semaphore.h>
 45 #include <linux/slab.h>
 46 #include <linux/seq_file.h>
 47 #include <net/9p/9p.h>
 48 #include <net/9p/client.h>
 49 #include <net/9p/transport.h>
 50 #include <rdma/ib_verbs.h>
 51 #include <rdma/rdma_cm.h>
 52 
 53 #define P9_PORT                 5640
 54 #define P9_RDMA_SQ_DEPTH        32
 55 #define P9_RDMA_RQ_DEPTH        32
 56 #define P9_RDMA_SEND_SGE        4
 57 #define P9_RDMA_RECV_SGE        4
 58 #define P9_RDMA_IRD             0
 59 #define P9_RDMA_ORD             0
 60 #define P9_RDMA_TIMEOUT         30000           /* 30 seconds */
 61 #define P9_RDMA_MAXSIZE         (1024*1024)     /* 1MB */
 62 
 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  * @timeout: Number of uSecs to wait for connection management events
 72  * @privport: Whether a privileged port may be used
 73  * @port: The port to use
 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_sem: Semaphore for the RQ
 78  * @excess_rc : Amount of posted Receive Contexts without a pending request.
 79  *              See rdma_request()
 80  * @addr: The remote peer's address
 81  * @req_lock: Protects the active request list
 82  * @cm_done: Completion event for connection management tracking
 83  */
 84 struct p9_trans_rdma {
 85         enum {
 86                 P9_RDMA_INIT,
 87                 P9_RDMA_ADDR_RESOLVED,
 88                 P9_RDMA_ROUTE_RESOLVED,
 89                 P9_RDMA_CONNECTED,
 90                 P9_RDMA_FLUSHING,
 91                 P9_RDMA_CLOSING,
 92                 P9_RDMA_CLOSED,
 93         } state;
 94         struct rdma_cm_id *cm_id;
 95         struct ib_pd *pd;
 96         struct ib_qp *qp;
 97         struct ib_cq *cq;
 98         long timeout;
 99         bool privport;
100         u16 port;
101         int sq_depth;
102         struct semaphore sq_sem;
103         int rq_depth;
104         struct semaphore rq_sem;
105         atomic_t excess_rc;
106         struct sockaddr_in addr;
107         spinlock_t req_lock;
108 
109         struct completion cm_done;
110 };
111 
112 /**
113  * p9_rdma_context - Keeps track of in-process WR
114  *
115  * @busa: Bus address to unmap when the WR completes
116  * @req: Keeps track of requests (send)
117  * @rc: Keepts track of replies (receive)
118  */
119 struct p9_rdma_req;
120 struct p9_rdma_context {
121         struct ib_cqe cqe;
122         dma_addr_t busa;
123         union {
124                 struct p9_req_t *req;
125                 struct p9_fcall *rc;
126         };
127 };
128 
129 /**
130  * p9_rdma_opts - Collection of mount options
131  * @port: port of connection
132  * @sq_depth: The requested depth of the SQ. This really doesn't need
133  * to be any deeper than the number of threads used in the client
134  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
135  * @timeout: Time to wait in msecs for CM events
136  */
137 struct p9_rdma_opts {
138         short port;
139         bool privport;
140         int sq_depth;
141         int rq_depth;
142         long timeout;
143 };
144 
145 /*
146  * Option Parsing (code inspired by NFS code)
147  */
148 enum {
149         /* Options that take integer arguments */
150         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
151         /* Options that take no argument */
152         Opt_privport,
153         Opt_err,
154 };
155 
156 static match_table_t tokens = {
157         {Opt_port, "port=%u"},
158         {Opt_sq_depth, "sq=%u"},
159         {Opt_rq_depth, "rq=%u"},
160         {Opt_timeout, "timeout=%u"},
161         {Opt_privport, "privport"},
162         {Opt_err, NULL},
163 };
164 
165 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
166 {
167         struct p9_trans_rdma *rdma = clnt->trans;
168 
169         if (rdma->port != P9_PORT)
170                 seq_printf(m, ",port=%u", rdma->port);
171         if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
172                 seq_printf(m, ",sq=%u", rdma->sq_depth);
173         if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
174                 seq_printf(m, ",rq=%u", rdma->rq_depth);
175         if (rdma->timeout != P9_RDMA_TIMEOUT)
176                 seq_printf(m, ",timeout=%lu", rdma->timeout);
177         if (rdma->privport)
178                 seq_puts(m, ",privport");
179         return 0;
180 }
181 
182 /**
183  * parse_opts - parse mount options into rdma options structure
184  * @params: options string passed from mount
185  * @opts: rdma transport-specific structure to parse options into
186  *
187  * Returns 0 upon success, -ERRNO upon failure
188  */
189 static int parse_opts(char *params, struct p9_rdma_opts *opts)
190 {
191         char *p;
192         substring_t args[MAX_OPT_ARGS];
193         int option;
194         char *options, *tmp_options;
195 
196         opts->port = P9_PORT;
197         opts->sq_depth = P9_RDMA_SQ_DEPTH;
198         opts->rq_depth = P9_RDMA_RQ_DEPTH;
199         opts->timeout = P9_RDMA_TIMEOUT;
200         opts->privport = false;
201 
202         if (!params)
203                 return 0;
204 
205         tmp_options = kstrdup(params, GFP_KERNEL);
206         if (!tmp_options) {
207                 p9_debug(P9_DEBUG_ERROR,
208                          "failed to allocate copy of option string\n");
209                 return -ENOMEM;
210         }
211         options = tmp_options;
212 
213         while ((p = strsep(&options, ",")) != NULL) {
214                 int token;
215                 int r;
216                 if (!*p)
217                         continue;
218                 token = match_token(p, tokens, args);
219                 if ((token != Opt_err) && (token != Opt_privport)) {
220                         r = match_int(&args[0], &option);
221                         if (r < 0) {
222                                 p9_debug(P9_DEBUG_ERROR,
223                                          "integer field, but no integer?\n");
224                                 continue;
225                         }
226                 }
227                 switch (token) {
228                 case Opt_port:
229                         opts->port = option;
230                         break;
231                 case Opt_sq_depth:
232                         opts->sq_depth = option;
233                         break;
234                 case Opt_rq_depth:
235                         opts->rq_depth = option;
236                         break;
237                 case Opt_timeout:
238                         opts->timeout = option;
239                         break;
240                 case Opt_privport:
241                         opts->privport = true;
242                         break;
243                 default:
244                         continue;
245                 }
246         }
247         /* RQ must be at least as large as the SQ */
248         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
249         kfree(tmp_options);
250         return 0;
251 }
252 
253 static int
254 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
255 {
256         struct p9_client *c = id->context;
257         struct p9_trans_rdma *rdma = c->trans;
258         switch (event->event) {
259         case RDMA_CM_EVENT_ADDR_RESOLVED:
260                 BUG_ON(rdma->state != P9_RDMA_INIT);
261                 rdma->state = P9_RDMA_ADDR_RESOLVED;
262                 break;
263 
264         case RDMA_CM_EVENT_ROUTE_RESOLVED:
265                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
266                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
267                 break;
268 
269         case RDMA_CM_EVENT_ESTABLISHED:
270                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
271                 rdma->state = P9_RDMA_CONNECTED;
272                 break;
273 
274         case RDMA_CM_EVENT_DISCONNECTED:
275                 if (rdma)
276                         rdma->state = P9_RDMA_CLOSED;
277                 if (c)
278                         c->status = Disconnected;
279                 break;
280 
281         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
282                 break;
283 
284         case RDMA_CM_EVENT_ADDR_CHANGE:
285         case RDMA_CM_EVENT_ROUTE_ERROR:
286         case RDMA_CM_EVENT_DEVICE_REMOVAL:
287         case RDMA_CM_EVENT_MULTICAST_JOIN:
288         case RDMA_CM_EVENT_MULTICAST_ERROR:
289         case RDMA_CM_EVENT_REJECTED:
290         case RDMA_CM_EVENT_CONNECT_REQUEST:
291         case RDMA_CM_EVENT_CONNECT_RESPONSE:
292         case RDMA_CM_EVENT_CONNECT_ERROR:
293         case RDMA_CM_EVENT_ADDR_ERROR:
294         case RDMA_CM_EVENT_UNREACHABLE:
295                 c->status = Disconnected;
296                 rdma_disconnect(rdma->cm_id);
297                 break;
298         default:
299                 BUG();
300         }
301         complete(&rdma->cm_done);
302         return 0;
303 }
304 
305 static void
306 recv_done(struct ib_cq *cq, struct ib_wc *wc)
307 {
308         struct p9_client *client = cq->cq_context;
309         struct p9_trans_rdma *rdma = client->trans;
310         struct p9_rdma_context *c =
311                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
312         struct p9_req_t *req;
313         int err = 0;
314         int16_t tag;
315 
316         req = NULL;
317         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
318                                                          DMA_FROM_DEVICE);
319 
320         if (wc->status != IB_WC_SUCCESS)
321                 goto err_out;
322 
323         err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
324         if (err)
325                 goto err_out;
326 
327         req = p9_tag_lookup(client, tag);
328         if (!req)
329                 goto err_out;
330 
331         /* Check that we have not yet received a reply for this request.
332          */
333         if (unlikely(req->rc)) {
334                 pr_err("Duplicate reply for request %d", tag);
335                 goto err_out;
336         }
337 
338         req->rc = c->rc;
339         p9_client_cb(client, req, REQ_STATUS_RCVD);
340 
341  out:
342         up(&rdma->rq_sem);
343         kfree(c);
344         return;
345 
346  err_out:
347         p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
348                         req, err, wc->status);
349         rdma->state = P9_RDMA_FLUSHING;
350         client->status = Disconnected;
351         goto out;
352 }
353 
354 static void
355 send_done(struct ib_cq *cq, struct ib_wc *wc)
356 {
357         struct p9_client *client = cq->cq_context;
358         struct p9_trans_rdma *rdma = client->trans;
359         struct p9_rdma_context *c =
360                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
361 
362         ib_dma_unmap_single(rdma->cm_id->device,
363                             c->busa, c->req->tc->size,
364                             DMA_TO_DEVICE);
365         up(&rdma->sq_sem);
366         kfree(c);
367 }
368 
369 static void qp_event_handler(struct ib_event *event, void *context)
370 {
371         p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
372                  event->event, context);
373 }
374 
375 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
376 {
377         if (!rdma)
378                 return;
379 
380         if (rdma->qp && !IS_ERR(rdma->qp))
381                 ib_destroy_qp(rdma->qp);
382 
383         if (rdma->pd && !IS_ERR(rdma->pd))
384                 ib_dealloc_pd(rdma->pd);
385 
386         if (rdma->cq && !IS_ERR(rdma->cq))
387                 ib_free_cq(rdma->cq);
388 
389         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
390                 rdma_destroy_id(rdma->cm_id);
391 
392         kfree(rdma);
393 }
394 
395 static int
396 post_recv(struct p9_client *client, struct p9_rdma_context *c)
397 {
398         struct p9_trans_rdma *rdma = client->trans;
399         struct ib_recv_wr wr, *bad_wr;
400         struct ib_sge sge;
401 
402         c->busa = ib_dma_map_single(rdma->cm_id->device,
403                                     c->rc->sdata, client->msize,
404                                     DMA_FROM_DEVICE);
405         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
406                 goto error;
407 
408         c->cqe.done = recv_done;
409 
410         sge.addr = c->busa;
411         sge.length = client->msize;
412         sge.lkey = rdma->pd->local_dma_lkey;
413 
414         wr.next = NULL;
415         wr.wr_cqe = &c->cqe;
416         wr.sg_list = &sge;
417         wr.num_sge = 1;
418         return ib_post_recv(rdma->qp, &wr, &bad_wr);
419 
420  error:
421         p9_debug(P9_DEBUG_ERROR, "EIO\n");
422         return -EIO;
423 }
424 
425 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
426 {
427         struct p9_trans_rdma *rdma = client->trans;
428         struct ib_send_wr wr, *bad_wr;
429         struct ib_sge sge;
430         int err = 0;
431         unsigned long flags;
432         struct p9_rdma_context *c = NULL;
433         struct p9_rdma_context *rpl_context = NULL;
434 
435         /* When an error occurs between posting the recv and the send,
436          * there will be a receive context posted without a pending request.
437          * Since there is no way to "un-post" it, we remember it and skip
438          * post_recv() for the next request.
439          * So here,
440          * see if we are this `next request' and need to absorb an excess rc.
441          * If yes, then drop and free our own, and do not recv_post().
442          **/
443         if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
444                 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
445                         /* Got one ! */
446                         kfree(req->rc);
447                         req->rc = NULL;
448                         goto dont_need_post_recv;
449                 } else {
450                         /* We raced and lost. */
451                         atomic_inc(&rdma->excess_rc);
452                 }
453         }
454 
455         /* Allocate an fcall for the reply */
456         rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
457         if (!rpl_context) {
458                 err = -ENOMEM;
459                 goto recv_error;
460         }
461         rpl_context->rc = req->rc;
462 
463         /*
464          * Post a receive buffer for this request. We need to ensure
465          * there is a reply buffer available for every outstanding
466          * request. A flushed request can result in no reply for an
467          * outstanding request, so we must keep a count to avoid
468          * overflowing the RQ.
469          */
470         if (down_interruptible(&rdma->rq_sem)) {
471                 err = -EINTR;
472                 goto recv_error;
473         }
474 
475         err = post_recv(client, rpl_context);
476         if (err) {
477                 p9_debug(P9_DEBUG_FCALL, "POST RECV failed\n");
478                 goto recv_error;
479         }
480         /* remove posted receive buffer from request structure */
481         req->rc = NULL;
482 
483 dont_need_post_recv:
484         /* Post the request */
485         c = kmalloc(sizeof *c, GFP_NOFS);
486         if (!c) {
487                 err = -ENOMEM;
488                 goto send_error;
489         }
490         c->req = req;
491 
492         c->busa = ib_dma_map_single(rdma->cm_id->device,
493                                     c->req->tc->sdata, c->req->tc->size,
494                                     DMA_TO_DEVICE);
495         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
496                 err = -EIO;
497                 goto send_error;
498         }
499 
500         c->cqe.done = send_done;
501 
502         sge.addr = c->busa;
503         sge.length = c->req->tc->size;
504         sge.lkey = rdma->pd->local_dma_lkey;
505 
506         wr.next = NULL;
507         wr.wr_cqe = &c->cqe;
508         wr.opcode = IB_WR_SEND;
509         wr.send_flags = IB_SEND_SIGNALED;
510         wr.sg_list = &sge;
511         wr.num_sge = 1;
512 
513         if (down_interruptible(&rdma->sq_sem)) {
514                 err = -EINTR;
515                 goto send_error;
516         }
517 
518         /* Mark request as `sent' *before* we actually send it,
519          * because doing if after could erase the REQ_STATUS_RCVD
520          * status in case of a very fast reply.
521          */
522         req->status = REQ_STATUS_SENT;
523         err = ib_post_send(rdma->qp, &wr, &bad_wr);
524         if (err)
525                 goto send_error;
526 
527         /* Success */
528         return 0;
529 
530  /* Handle errors that happened during or while preparing the send: */
531  send_error:
532         req->status = REQ_STATUS_ERROR;
533         kfree(c);
534         p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
535 
536         /* Ach.
537          *  We did recv_post(), but not send. We have one recv_post in excess.
538          */
539         atomic_inc(&rdma->excess_rc);
540         return err;
541 
542  /* Handle errors that happened during or while preparing post_recv(): */
543  recv_error:
544         kfree(rpl_context);
545         spin_lock_irqsave(&rdma->req_lock, flags);
546         if (rdma->state < P9_RDMA_CLOSING) {
547                 rdma->state = P9_RDMA_CLOSING;
548                 spin_unlock_irqrestore(&rdma->req_lock, flags);
549                 rdma_disconnect(rdma->cm_id);
550         } else
551                 spin_unlock_irqrestore(&rdma->req_lock, flags);
552         return err;
553 }
554 
555 static void rdma_close(struct p9_client *client)
556 {
557         struct p9_trans_rdma *rdma;
558 
559         if (!client)
560                 return;
561 
562         rdma = client->trans;
563         if (!rdma)
564                 return;
565 
566         client->status = Disconnected;
567         rdma_disconnect(rdma->cm_id);
568         rdma_destroy_trans(rdma);
569 }
570 
571 /**
572  * alloc_rdma - Allocate and initialize the rdma transport structure
573  * @opts: Mount options structure
574  */
575 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
576 {
577         struct p9_trans_rdma *rdma;
578 
579         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
580         if (!rdma)
581                 return NULL;
582 
583         rdma->port = opts->port;
584         rdma->privport = opts->privport;
585         rdma->sq_depth = opts->sq_depth;
586         rdma->rq_depth = opts->rq_depth;
587         rdma->timeout = opts->timeout;
588         spin_lock_init(&rdma->req_lock);
589         init_completion(&rdma->cm_done);
590         sema_init(&rdma->sq_sem, rdma->sq_depth);
591         sema_init(&rdma->rq_sem, rdma->rq_depth);
592         atomic_set(&rdma->excess_rc, 0);
593 
594         return rdma;
595 }
596 
597 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
598 {
599         /* Nothing to do here.
600          * We will take care of it (if we have to) in rdma_cancelled()
601          */
602         return 1;
603 }
604 
605 /* A request has been fully flushed without a reply.
606  * That means we have posted one buffer in excess.
607  */
608 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
609 {
610         struct p9_trans_rdma *rdma = client->trans;
611         atomic_inc(&rdma->excess_rc);
612         return 0;
613 }
614 
615 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
616 {
617         struct sockaddr_in cl = {
618                 .sin_family = AF_INET,
619                 .sin_addr.s_addr = htonl(INADDR_ANY),
620         };
621         int port, err = -EINVAL;
622 
623         for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
624                 cl.sin_port = htons((ushort)port);
625                 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
626                 if (err != -EADDRINUSE)
627                         break;
628         }
629         return err;
630 }
631 
632 /**
633  * rdma_create_trans - Transport method for creating a transport instance
634  * @client: client instance
635  * @addr: IP address string
636  * @args: Mount options string
637  */
638 static int
639 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
640 {
641         int err;
642         struct p9_rdma_opts opts;
643         struct p9_trans_rdma *rdma;
644         struct rdma_conn_param conn_param;
645         struct ib_qp_init_attr qp_attr;
646 
647         /* Parse the transport specific mount options */
648         err = parse_opts(args, &opts);
649         if (err < 0)
650                 return err;
651 
652         /* Create and initialize the RDMA transport structure */
653         rdma = alloc_rdma(&opts);
654         if (!rdma)
655                 return -ENOMEM;
656 
657         /* Create the RDMA CM ID */
658         rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
659                                      RDMA_PS_TCP, IB_QPT_RC);
660         if (IS_ERR(rdma->cm_id))
661                 goto error;
662 
663         /* Associate the client with the transport */
664         client->trans = rdma;
665 
666         /* Bind to a privileged port if we need to */
667         if (opts.privport) {
668                 err = p9_rdma_bind_privport(rdma);
669                 if (err < 0) {
670                         pr_err("%s (%d): problem binding to privport: %d\n",
671                                __func__, task_pid_nr(current), -err);
672                         goto error;
673                 }
674         }
675 
676         /* Resolve the server's address */
677         rdma->addr.sin_family = AF_INET;
678         rdma->addr.sin_addr.s_addr = in_aton(addr);
679         rdma->addr.sin_port = htons(opts.port);
680         err = rdma_resolve_addr(rdma->cm_id, NULL,
681                                 (struct sockaddr *)&rdma->addr,
682                                 rdma->timeout);
683         if (err)
684                 goto error;
685         err = wait_for_completion_interruptible(&rdma->cm_done);
686         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
687                 goto error;
688 
689         /* Resolve the route to the server */
690         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
691         if (err)
692                 goto error;
693         err = wait_for_completion_interruptible(&rdma->cm_done);
694         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
695                 goto error;
696 
697         /* Create the Completion Queue */
698         rdma->cq = ib_alloc_cq(rdma->cm_id->device, client,
699                         opts.sq_depth + opts.rq_depth + 1,
700                         0, IB_POLL_SOFTIRQ);
701         if (IS_ERR(rdma->cq))
702                 goto error;
703 
704         /* Create the Protection Domain */
705         rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
706         if (IS_ERR(rdma->pd))
707                 goto error;
708 
709         /* Create the Queue Pair */
710         memset(&qp_attr, 0, sizeof qp_attr);
711         qp_attr.event_handler = qp_event_handler;
712         qp_attr.qp_context = client;
713         qp_attr.cap.max_send_wr = opts.sq_depth;
714         qp_attr.cap.max_recv_wr = opts.rq_depth;
715         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
716         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
717         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
718         qp_attr.qp_type = IB_QPT_RC;
719         qp_attr.send_cq = rdma->cq;
720         qp_attr.recv_cq = rdma->cq;
721         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
722         if (err)
723                 goto error;
724         rdma->qp = rdma->cm_id->qp;
725 
726         /* Request a connection */
727         memset(&conn_param, 0, sizeof(conn_param));
728         conn_param.private_data = NULL;
729         conn_param.private_data_len = 0;
730         conn_param.responder_resources = P9_RDMA_IRD;
731         conn_param.initiator_depth = P9_RDMA_ORD;
732         err = rdma_connect(rdma->cm_id, &conn_param);
733         if (err)
734                 goto error;
735         err = wait_for_completion_interruptible(&rdma->cm_done);
736         if (err || (rdma->state != P9_RDMA_CONNECTED))
737                 goto error;
738 
739         client->status = Connected;
740 
741         return 0;
742 
743 error:
744         rdma_destroy_trans(rdma);
745         return -ENOTCONN;
746 }
747 
748 static struct p9_trans_module p9_rdma_trans = {
749         .name = "rdma",
750         .maxsize = P9_RDMA_MAXSIZE,
751         .def = 0,
752         .owner = THIS_MODULE,
753         .create = rdma_create_trans,
754         .close = rdma_close,
755         .request = rdma_request,
756         .cancel = rdma_cancel,
757         .cancelled = rdma_cancelled,
758         .show_options = p9_rdma_show_options,
759 };
760 
761 /**
762  * p9_trans_rdma_init - Register the 9P RDMA transport driver
763  */
764 static int __init p9_trans_rdma_init(void)
765 {
766         v9fs_register_trans(&p9_rdma_trans);
767         return 0;
768 }
769 
770 static void __exit p9_trans_rdma_exit(void)
771 {
772         v9fs_unregister_trans(&p9_rdma_trans);
773 }
774 
775 module_init(p9_trans_rdma_init);
776 module_exit(p9_trans_rdma_exit);
777 
778 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
779 MODULE_DESCRIPTION("RDMA Transport for 9P");
780 MODULE_LICENSE("Dual BSD/GPL");
781 

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