net/9p/trans_rdma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/fs/9p/trans_rdma.c
   4  *
   5  * RDMA transport layer based on the trans_fd.c implementation.
   6  *
   7  *  Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
   8  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
   9  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
  10  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  11  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/in.h>
  17 #include <linux/module.h>
  18 #include <linux/net.h>
  19 #include <linux/ipv6.h>
  20 #include <linux/kthread.h>
  21 #include <linux/errno.h>
  22 #include <linux/kernel.h>
  23 #include <linux/un.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/inet.h>
  26 #include <linux/idr.h>
  27 #include <linux/file.h>
  28 #include <linux/parser.h>
  29 #include <linux/semaphore.h>
  30 #include <linux/slab.h>
  31 #include <linux/seq_file.h>
  32 #include <net/9p/9p.h>
  33 #include <net/9p/client.h>
  34 #include <net/9p/transport.h>
  35 #include <rdma/ib_verbs.h>
  36 #include <rdma/rdma_cm.h>
  37
  38 #define P9_PORT                 5640
  39 #define P9_RDMA_SQ_DEPTH        32
  40 #define P9_RDMA_RQ_DEPTH        32
  41 #define P9_RDMA_SEND_SGE        4
  42 #define P9_RDMA_RECV_SGE        4
  43 #define P9_RDMA_IRD             0
  44 #define P9_RDMA_ORD             0
  45 #define P9_RDMA_TIMEOUT         30000           /* 30 seconds */
  46 #define P9_RDMA_MAXSIZE         (1024*1024)     /* 1MB */
  47
  48 /**
  49  * struct p9_trans_rdma - RDMA transport instance
  50  *
  51  * @state: tracks the transport state machine for connection setup and tear down
  52  * @cm_id: The RDMA CM ID
  53  * @pd: Protection Domain pointer
  54  * @qp: Queue Pair pointer
  55  * @cq: Completion Queue pointer
  56  * @timeout: Number of uSecs to wait for connection management events
  57  * @privport: Whether a privileged port may be used
  58  * @port: The port to use
  59  * @sq_depth: The depth of the Send Queue
  60  * @sq_sem: Semaphore for the SQ
  61  * @rq_depth: The depth of the Receive Queue.
  62  * @rq_sem: Semaphore for the RQ
  63  * @excess_rc : Amount of posted Receive Contexts without a pending request.
  64  *              See rdma_request()
  65  * @addr: The remote peer's address
  66  * @req_lock: Protects the active request list
  67  * @cm_done: Completion event for connection management tracking
  68  */
  69 struct p9_trans_rdma {
  70         enum {
  71                 P9_RDMA_INIT,
  72                 P9_RDMA_ADDR_RESOLVED,
  73                 P9_RDMA_ROUTE_RESOLVED,
  74                 P9_RDMA_CONNECTED,
  75                 P9_RDMA_FLUSHING,
  76                 P9_RDMA_CLOSING,
  77                 P9_RDMA_CLOSED,
  78         } state;
  79         struct rdma_cm_id *cm_id;
  80         struct ib_pd *pd;
  81         struct ib_qp *qp;
  82         struct ib_cq *cq;
  83         long timeout;
  84         bool privport;
  85         u16 port;
  86         int sq_depth;
  87         struct semaphore sq_sem;
  88         int rq_depth;
  89         struct semaphore rq_sem;
  90         atomic_t excess_rc;
  91         struct sockaddr_in addr;
  92         spinlock_t req_lock;
  93
  94         struct completion cm_done;
  95 };
  96
  97 struct p9_rdma_req;
  98
  99 /**
 100  * struct p9_rdma_context - Keeps track of in-process WR
 101  *
 102  * @busa: Bus address to unmap when the WR completes
 103  * @req: Keeps track of requests (send)
 104  * @rc: Keepts track of replies (receive)
 105  */
 106 struct p9_rdma_context {
 107         struct ib_cqe cqe;
 108         dma_addr_t busa;
 109         union {
 110                 struct p9_req_t *req;
 111                 struct p9_fcall rc;
 112         };
 113 };
 114
 115 /**
 116  * struct p9_rdma_opts - Collection of mount options
 117  * @port: port of connection
 118  * @sq_depth: The requested depth of the SQ. This really doesn't need
 119  * to be any deeper than the number of threads used in the client
 120  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
 121  * @timeout: Time to wait in msecs for CM events
 122  */
 123 struct p9_rdma_opts {
 124         short port;
 125         bool privport;
 126         int sq_depth;
 127         int rq_depth;
 128         long timeout;
 129 };
 130
 131 /*
 132  * Option Parsing (code inspired by NFS code)
 133  */
 134 enum {
 135         /* Options that take integer arguments */
 136         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
 137         /* Options that take no argument */
 138         Opt_privport,
 139         Opt_err,
 140 };
 141
 142 static match_table_t tokens = {
 143         {Opt_port, "port=%u"},
 144         {Opt_sq_depth, "sq=%u"},
 145         {Opt_rq_depth, "rq=%u"},
 146         {Opt_timeout, "timeout=%u"},
 147         {Opt_privport, "privport"},
 148         {Opt_err, NULL},
 149 };
 150
 151 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
 152 {
 153         struct p9_trans_rdma *rdma = clnt->trans;
 154
 155         if (rdma->port != P9_PORT)
 156                 seq_printf(m, ",port=%u", rdma->port);
 157         if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
 158                 seq_printf(m, ",sq=%u", rdma->sq_depth);
 159         if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
 160                 seq_printf(m, ",rq=%u", rdma->rq_depth);
 161         if (rdma->timeout != P9_RDMA_TIMEOUT)
 162                 seq_printf(m, ",timeout=%lu", rdma->timeout);
 163         if (rdma->privport)
 164                 seq_puts(m, ",privport");
 165         return 0;
 166 }
 167
 168 /**
 169  * parse_opts - parse mount options into rdma options structure
 170  * @params: options string passed from mount
 171  * @opts: rdma transport-specific structure to parse options into
 172  *
 173  * Returns 0 upon success, -ERRNO upon failure
 174  */
 175 static int parse_opts(char *params, struct p9_rdma_opts *opts)
 176 {
 177         char *p;
 178         substring_t args[MAX_OPT_ARGS];
 179         int option;
 180         char *options, *tmp_options;
 181
 182         opts->port = P9_PORT;
 183         opts->sq_depth = P9_RDMA_SQ_DEPTH;
 184         opts->rq_depth = P9_RDMA_RQ_DEPTH;
 185         opts->timeout = P9_RDMA_TIMEOUT;
 186         opts->privport = false;
 187
 188         if (!params)
 189                 return 0;
 190
 191         tmp_options = kstrdup(params, GFP_KERNEL);
 192         if (!tmp_options) {
 193                 p9_debug(P9_DEBUG_ERROR,
 194                          "failed to allocate copy of option string\n");
 195                 return -ENOMEM;
 196         }
 197         options = tmp_options;
 198
 199         while ((p = strsep(&options, ",")) != NULL) {
 200                 int token;
 201                 int r;
 202                 if (!*p)
 203                         continue;
 204                 token = match_token(p, tokens, args);
 205                 if ((token != Opt_err) && (token != Opt_privport)) {
 206                         r = match_int(&args[0], &option);
 207                         if (r < 0) {
 208                                 p9_debug(P9_DEBUG_ERROR,
 209                                          "integer field, but no integer?\n");
 210                                 continue;
 211                         }
 212                 }
 213                 switch (token) {
 214                 case Opt_port:
 215                         opts->port = option;
 216                         break;
 217                 case Opt_sq_depth:
 218                         opts->sq_depth = option;
 219                         break;
 220                 case Opt_rq_depth:
 221                         opts->rq_depth = option;
 222                         break;
 223                 case Opt_timeout:
 224                         opts->timeout = option;
 225                         break;
 226                 case Opt_privport:
 227                         opts->privport = true;
 228                         break;
 229                 default:
 230                         continue;
 231                 }
 232         }
 233         /* RQ must be at least as large as the SQ */
 234         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
 235         kfree(tmp_options);
 236         return 0;
 237 }
 238
 239 static int
 240 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
 241 {
 242         struct p9_client *c = id->context;
 243         struct p9_trans_rdma *rdma = c->trans;
 244         switch (event->event) {
 245         case RDMA_CM_EVENT_ADDR_RESOLVED:
 246                 BUG_ON(rdma->state != P9_RDMA_INIT);
 247                 rdma->state = P9_RDMA_ADDR_RESOLVED;
 248                 break;
 249
 250         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 251                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
 252                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
 253                 break;
 254
 255         case RDMA_CM_EVENT_ESTABLISHED:
 256                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
 257                 rdma->state = P9_RDMA_CONNECTED;
 258                 break;
 259
 260         case RDMA_CM_EVENT_DISCONNECTED:
 261                 if (rdma)
 262                         rdma->state = P9_RDMA_CLOSED;
 263                 c->status = Disconnected;
 264                 break;
 265
 266         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 267                 break;
 268
 269         case RDMA_CM_EVENT_ADDR_CHANGE:
 270         case RDMA_CM_EVENT_ROUTE_ERROR:
 271         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 272         case RDMA_CM_EVENT_MULTICAST_JOIN:
 273         case RDMA_CM_EVENT_MULTICAST_ERROR:
 274         case RDMA_CM_EVENT_REJECTED:
 275         case RDMA_CM_EVENT_CONNECT_REQUEST:
 276         case RDMA_CM_EVENT_CONNECT_RESPONSE:
 277         case RDMA_CM_EVENT_CONNECT_ERROR:
 278         case RDMA_CM_EVENT_ADDR_ERROR:
 279         case RDMA_CM_EVENT_UNREACHABLE:
 280                 c->status = Disconnected;
 281                 rdma_disconnect(rdma->cm_id);
 282                 break;
 283         default:
 284                 BUG();
 285         }
 286         complete(&rdma->cm_done);
 287         return 0;
 288 }
 289
 290 static void
 291 recv_done(struct ib_cq *cq, struct ib_wc *wc)
 292 {
 293         struct p9_client *client = cq->cq_context;
 294         struct p9_trans_rdma *rdma = client->trans;
 295         struct p9_rdma_context *c =
 296                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 297         struct p9_req_t *req;
 298         int err = 0;
 299         int16_t tag;
 300
 301         req = NULL;
 302         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
 303                                                          DMA_FROM_DEVICE);
 304
 305         if (wc->status != IB_WC_SUCCESS)
 306                 goto err_out;
 307
 308         c->rc.size = wc->byte_len;
 309         err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1);
 310         if (err)
 311                 goto err_out;
 312
 313         req = p9_tag_lookup(client, tag);
 314         if (!req)
 315                 goto err_out;
 316
 317         /* Check that we have not yet received a reply for this request.
 318          */
 319         if (unlikely(req->rc.sdata)) {
 320                 pr_err("Duplicate reply for request %d", tag);
 321                 goto err_out;
 322         }
 323
 324         req->rc.size = c->rc.size;
 325         req->rc.sdata = c->rc.sdata;
 326         p9_client_cb(client, req, REQ_STATUS_RCVD);
 327
 328  out:
 329         up(&rdma->rq_sem);
 330         kfree(c);
 331         return;
 332
 333  err_out:
 334         p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
 335                         req, err, wc->status);
 336         rdma->state = P9_RDMA_FLUSHING;
 337         client->status = Disconnected;
 338         goto out;
 339 }
 340
 341 static void
 342 send_done(struct ib_cq *cq, struct ib_wc *wc)
 343 {
 344         struct p9_client *client = cq->cq_context;
 345         struct p9_trans_rdma *rdma = client->trans;
 346         struct p9_rdma_context *c =
 347                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 348
 349         ib_dma_unmap_single(rdma->cm_id->device,
 350                             c->busa, c->req->tc.size,
 351                             DMA_TO_DEVICE);
 352         up(&rdma->sq_sem);
 353         p9_req_put(c->req);
 354         kfree(c);
 355 }
 356
 357 static void qp_event_handler(struct ib_event *event, void *context)
 358 {
 359         p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
 360                  event->event, context);
 361 }
 362
 363 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
 364 {
 365         if (!rdma)
 366                 return;
 367
 368         if (rdma->qp && !IS_ERR(rdma->qp))
 369                 ib_destroy_qp(rdma->qp);
 370
 371         if (rdma->pd && !IS_ERR(rdma->pd))
 372                 ib_dealloc_pd(rdma->pd);
 373
 374         if (rdma->cq && !IS_ERR(rdma->cq))
 375                 ib_free_cq(rdma->cq);
 376
 377         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
 378                 rdma_destroy_id(rdma->cm_id);
 379
 380         kfree(rdma);
 381 }
 382
 383 static int
 384 post_recv(struct p9_client *client, struct p9_rdma_context *c)
 385 {
 386         struct p9_trans_rdma *rdma = client->trans;
 387         struct ib_recv_wr wr;
 388         struct ib_sge sge;
 389
 390         c->busa = ib_dma_map_single(rdma->cm_id->device,
 391                                     c->rc.sdata, client->msize,
 392                                     DMA_FROM_DEVICE);
 393         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
 394                 goto error;
 395
 396         c->cqe.done = recv_done;
 397
 398         sge.addr = c->busa;
 399         sge.length = client->msize;
 400         sge.lkey = rdma->pd->local_dma_lkey;
 401
 402         wr.next = NULL;
 403         wr.wr_cqe = &c->cqe;
 404         wr.sg_list = &sge;
 405         wr.num_sge = 1;
 406         return ib_post_recv(rdma->qp, &wr, NULL);
 407
 408  error:
 409         p9_debug(P9_DEBUG_ERROR, "EIO\n");
 410         return -EIO;
 411 }
 412
 413 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 414 {
 415         struct p9_trans_rdma *rdma = client->trans;
 416         struct ib_send_wr wr;
 417         struct ib_sge sge;
 418         int err = 0;
 419         unsigned long flags;
 420         struct p9_rdma_context *c = NULL;
 421         struct p9_rdma_context *rpl_context = NULL;
 422
 423         /* When an error occurs between posting the recv and the send,
 424          * there will be a receive context posted without a pending request.
 425          * Since there is no way to "un-post" it, we remember it and skip
 426          * post_recv() for the next request.
 427          * So here,
 428          * see if we are this `next request' and need to absorb an excess rc.
 429          * If yes, then drop and free our own, and do not recv_post().
 430          **/
 431         if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
 432                 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
 433                         /* Got one! */
 434                         p9_fcall_fini(&req->rc);
 435                         req->rc.sdata = NULL;
 436                         goto dont_need_post_recv;
 437                 } else {
 438                         /* We raced and lost. */
 439                         atomic_inc(&rdma->excess_rc);
 440                 }
 441         }
 442
 443         /* Allocate an fcall for the reply */
 444         rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
 445         if (!rpl_context) {
 446                 err = -ENOMEM;
 447                 goto recv_error;
 448         }
 449         rpl_context->rc.sdata = req->rc.sdata;
 450
 451         /*
 452          * Post a receive buffer for this request. We need to ensure
 453          * there is a reply buffer available for every outstanding
 454          * request. A flushed request can result in no reply for an
 455          * outstanding request, so we must keep a count to avoid
 456          * overflowing the RQ.
 457          */
 458         if (down_interruptible(&rdma->rq_sem)) {
 459                 err = -EINTR;
 460                 goto recv_error;
 461         }
 462
 463         err = post_recv(client, rpl_context);
 464         if (err) {
 465                 p9_debug(P9_DEBUG_ERROR, "POST RECV failed: %d\n", err);
 466                 goto recv_error;
 467         }
 468         /* remove posted receive buffer from request structure */
 469         req->rc.sdata = NULL;
 470
 471 dont_need_post_recv:
 472         /* Post the request */
 473         c = kmalloc(sizeof *c, GFP_NOFS);
 474         if (!c) {
 475                 err = -ENOMEM;
 476                 goto send_error;
 477         }
 478         c->req = req;
 479
 480         c->busa = ib_dma_map_single(rdma->cm_id->device,
 481                                     c->req->tc.sdata, c->req->tc.size,
 482                                     DMA_TO_DEVICE);
 483         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
 484                 err = -EIO;
 485                 goto send_error;
 486         }
 487
 488         c->cqe.done = send_done;
 489
 490         sge.addr = c->busa;
 491         sge.length = c->req->tc.size;
 492         sge.lkey = rdma->pd->local_dma_lkey;
 493
 494         wr.next = NULL;
 495         wr.wr_cqe = &c->cqe;
 496         wr.opcode = IB_WR_SEND;
 497         wr.send_flags = IB_SEND_SIGNALED;
 498         wr.sg_list = &sge;
 499         wr.num_sge = 1;
 500
 501         if (down_interruptible(&rdma->sq_sem)) {
 502                 err = -EINTR;
 503                 goto send_error;
 504         }
 505
 506         /* Mark request as `sent' *before* we actually send it,
 507          * because doing if after could erase the REQ_STATUS_RCVD
 508          * status in case of a very fast reply.
 509          */
 510         req->status = REQ_STATUS_SENT;
 511         err = ib_post_send(rdma->qp, &wr, NULL);
 512         if (err)
 513                 goto send_error;
 514
 515         /* Success */
 516         return 0;
 517
 518  /* Handle errors that happened during or while preparing the send: */
 519  send_error:
 520         req->status = REQ_STATUS_ERROR;
 521         kfree(c);
 522         p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
 523
 524         /* Ach.
 525          *  We did recv_post(), but not send. We have one recv_post in excess.
 526          */
 527         atomic_inc(&rdma->excess_rc);
 528         return err;
 529
 530  /* Handle errors that happened during or while preparing post_recv(): */
 531  recv_error:
 532         kfree(rpl_context);
 533         spin_lock_irqsave(&rdma->req_lock, flags);
 534         if (err != -EINTR && rdma->state < P9_RDMA_CLOSING) {
 535                 rdma->state = P9_RDMA_CLOSING;
 536                 spin_unlock_irqrestore(&rdma->req_lock, flags);
 537                 rdma_disconnect(rdma->cm_id);
 538         } else
 539                 spin_unlock_irqrestore(&rdma->req_lock, flags);
 540         return err;
 541 }
 542
 543 static void rdma_close(struct p9_client *client)
 544 {
 545         struct p9_trans_rdma *rdma;
 546
 547         if (!client)
 548                 return;
 549
 550         rdma = client->trans;
 551         if (!rdma)
 552                 return;
 553
 554         client->status = Disconnected;
 555         rdma_disconnect(rdma->cm_id);
 556         rdma_destroy_trans(rdma);
 557 }
 558
 559 /**
 560  * alloc_rdma - Allocate and initialize the rdma transport structure
 561  * @opts: Mount options structure
 562  */
 563 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
 564 {
 565         struct p9_trans_rdma *rdma;
 566
 567         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
 568         if (!rdma)
 569                 return NULL;
 570
 571         rdma->port = opts->port;
 572         rdma->privport = opts->privport;
 573         rdma->sq_depth = opts->sq_depth;
 574         rdma->rq_depth = opts->rq_depth;
 575         rdma->timeout = opts->timeout;
 576         spin_lock_init(&rdma->req_lock);
 577         init_completion(&rdma->cm_done);
 578         sema_init(&rdma->sq_sem, rdma->sq_depth);
 579         sema_init(&rdma->rq_sem, rdma->rq_depth);
 580         atomic_set(&rdma->excess_rc, 0);
 581
 582         return rdma;
 583 }
 584
 585 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
 586 {
 587         /* Nothing to do here.
 588          * We will take care of it (if we have to) in rdma_cancelled()
 589          */
 590         return 1;
 591 }
 592
 593 /* A request has been fully flushed without a reply.
 594  * That means we have posted one buffer in excess.
 595  */
 596 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
 597 {
 598         struct p9_trans_rdma *rdma = client->trans;
 599         atomic_inc(&rdma->excess_rc);
 600         return 0;
 601 }
 602
 603 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
 604 {
 605         struct sockaddr_in cl = {
 606                 .sin_family = AF_INET,
 607                 .sin_addr.s_addr = htonl(INADDR_ANY),
 608         };
 609         int port, err = -EINVAL;
 610
 611         for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
 612                 cl.sin_port = htons((ushort)port);
 613                 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
 614                 if (err != -EADDRINUSE)
 615                         break;
 616         }
 617         return err;
 618 }
 619
 620 /**
 621  * rdma_create_trans - Transport method for creating a transport instance
 622  * @client: client instance
 623  * @addr: IP address string
 624  * @args: Mount options string
 625  */
 626 static int
 627 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
 628 {
 629         int err;
 630         struct p9_rdma_opts opts;
 631         struct p9_trans_rdma *rdma;
 632         struct rdma_conn_param conn_param;
 633         struct ib_qp_init_attr qp_attr;
 634
 635         if (addr == NULL)
 636                 return -EINVAL;
 637
 638         /* Parse the transport specific mount options */
 639         err = parse_opts(args, &opts);
 640         if (err < 0)
 641                 return err;
 642
 643         /* Create and initialize the RDMA transport structure */
 644         rdma = alloc_rdma(&opts);
 645         if (!rdma)
 646                 return -ENOMEM;
 647
 648         /* Create the RDMA CM ID */
 649         rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
 650                                      RDMA_PS_TCP, IB_QPT_RC);
 651         if (IS_ERR(rdma->cm_id))
 652                 goto error;
 653
 654         /* Associate the client with the transport */
 655         client->trans = rdma;
 656
 657         /* Bind to a privileged port if we need to */
 658         if (opts.privport) {
 659                 err = p9_rdma_bind_privport(rdma);
 660                 if (err < 0) {
 661                         pr_err("%s (%d): problem binding to privport: %d\n",
 662                                __func__, task_pid_nr(current), -err);
 663                         goto error;
 664                 }
 665         }
 666
 667         /* Resolve the server's address */
 668         rdma->addr.sin_family = AF_INET;
 669         rdma->addr.sin_addr.s_addr = in_aton(addr);
 670         rdma->addr.sin_port = htons(opts.port);
 671         err = rdma_resolve_addr(rdma->cm_id, NULL,
 672                                 (struct sockaddr *)&rdma->addr,
 673                                 rdma->timeout);
 674         if (err)
 675                 goto error;
 676         err = wait_for_completion_interruptible(&rdma->cm_done);
 677         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
 678                 goto error;
 679
 680         /* Resolve the route to the server */
 681         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
 682         if (err)
 683                 goto error;
 684         err = wait_for_completion_interruptible(&rdma->cm_done);
 685         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
 686                 goto error;
 687
 688         /* Create the Completion Queue */
 689         rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
 690                                    opts.sq_depth + opts.rq_depth + 1,
 691                                    IB_POLL_SOFTIRQ);
 692         if (IS_ERR(rdma->cq))
 693                 goto error;
 694
 695         /* Create the Protection Domain */
 696         rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
 697         if (IS_ERR(rdma->pd))
 698                 goto error;
 699
 700         /* Create the Queue Pair */
 701         memset(&qp_attr, 0, sizeof qp_attr);
 702         qp_attr.event_handler = qp_event_handler;
 703         qp_attr.qp_context = client;
 704         qp_attr.cap.max_send_wr = opts.sq_depth;
 705         qp_attr.cap.max_recv_wr = opts.rq_depth;
 706         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
 707         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
 708         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 709         qp_attr.qp_type = IB_QPT_RC;
 710         qp_attr.send_cq = rdma->cq;
 711         qp_attr.recv_cq = rdma->cq;
 712         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
 713         if (err)
 714                 goto error;
 715         rdma->qp = rdma->cm_id->qp;
 716
 717         /* Request a connection */
 718         memset(&conn_param, 0, sizeof(conn_param));
 719         conn_param.private_data = NULL;
 720         conn_param.private_data_len = 0;
 721         conn_param.responder_resources = P9_RDMA_IRD;
 722         conn_param.initiator_depth = P9_RDMA_ORD;
 723         err = rdma_connect(rdma->cm_id, &conn_param);
 724         if (err)
 725                 goto error;
 726         err = wait_for_completion_interruptible(&rdma->cm_done);
 727         if (err || (rdma->state != P9_RDMA_CONNECTED))
 728                 goto error;
 729
 730         client->status = Connected;
 731
 732         return 0;
 733
 734 error:
 735         rdma_destroy_trans(rdma);
 736         return -ENOTCONN;
 737 }
 738
 739 static struct p9_trans_module p9_rdma_trans = {
 740         .name = "rdma",
 741         .maxsize = P9_RDMA_MAXSIZE,
 742         .def = 0,
 743         .owner = THIS_MODULE,
 744         .create = rdma_create_trans,
 745         .close = rdma_close,
 746         .request = rdma_request,
 747         .cancel = rdma_cancel,
 748         .cancelled = rdma_cancelled,
 749         .show_options = p9_rdma_show_options,
 750 };
 751
 752 /**
 753  * p9_trans_rdma_init - Register the 9P RDMA transport driver
 754  */
 755 static int __init p9_trans_rdma_init(void)
 756 {
 757         v9fs_register_trans(&p9_rdma_trans);
 758         return 0;
 759 }
 760
 761 static void __exit p9_trans_rdma_exit(void)
 762 {
 763         v9fs_unregister_trans(&p9_rdma_trans);
 764 }
 765
 766 module_init(p9_trans_rdma_init);
 767 module_exit(p9_trans_rdma_exit);
 768
 769 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
 770 MODULE_DESCRIPTION("RDMA Transport for 9P");
 771 MODULE_LICENSE("Dual BSD/GPL");