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