git.oblomov.eu Git - linux-2.6/blob - net/sunrpc/xprtrdma/transport.c

   1 /*
   2  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the BSD-type
   8  * license below:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  *      Redistributions of source code must retain the above copyright
  15  *      notice, this list of conditions and the following disclaimer.
  16  *
  17  *      Redistributions in binary form must reproduce the above
  18  *      copyright notice, this list of conditions and the following
  19  *      disclaimer in the documentation and/or other materials provided
  20  *      with the distribution.
  21  *
  22  *      Neither the name of the Network Appliance, Inc. nor the names of
  23  *      its contributors may be used to endorse or promote products
  24  *      derived from this software without specific prior written
  25  *      permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  */
  39
  40 /*
  41  * transport.c
  42  *
  43  * This file contains the top-level implementation of an RPC RDMA
  44  * transport.
  45  *
  46  * Naming convention: functions beginning with xprt_ are part of the
  47  * transport switch. All others are RPC RDMA internal.
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/init.h>
  52 #include <linux/seq_file.h>
  53
  54 #include "xprt_rdma.h"
  55
  56 #ifdef RPC_DEBUG
  57 # define RPCDBG_FACILITY        RPCDBG_TRANS
  58 #endif
  59
  60 MODULE_LICENSE("Dual BSD/GPL");
  61
  62 MODULE_DESCRIPTION("RPC/RDMA Transport for Linux kernel NFS");
  63 MODULE_AUTHOR("Network Appliance, Inc.");
  64
  65 /*
  66  * tunables
  67  */
  68
  69 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  70 static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  71 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  72 static unsigned int xprt_rdma_inline_write_padding;
  73 static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
  74                 int xprt_rdma_pad_optimize = 0;
  75
  76 #ifdef RPC_DEBUG
  77
  78 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  79 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  80 static unsigned int zero;
  81 static unsigned int max_padding = PAGE_SIZE;
  82 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  83 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  84
  85 static struct ctl_table_header *sunrpc_table_header;
  86
  87 static ctl_table xr_tunables_table[] = {
  88         {
  89                 .ctl_name       = CTL_UNNUMBERED,
  90                 .procname       = "rdma_slot_table_entries",
  91                 .data           = &xprt_rdma_slot_table_entries,
  92                 .maxlen         = sizeof(unsigned int),
  93                 .mode           = 0644,
  94                 .proc_handler   = &proc_dointvec_minmax,
  95                 .strategy       = &sysctl_intvec,
  96                 .extra1         = &min_slot_table_size,
  97                 .extra2         = &max_slot_table_size
  98         },
  99         {
 100                 .ctl_name       = CTL_UNNUMBERED,
 101                 .procname       = "rdma_max_inline_read",
 102                 .data           = &xprt_rdma_max_inline_read,
 103                 .maxlen         = sizeof(unsigned int),
 104                 .mode           = 0644,
 105                 .proc_handler   = &proc_dointvec,
 106                 .strategy       = &sysctl_intvec,
 107         },
 108         {
 109                 .ctl_name       = CTL_UNNUMBERED,
 110                 .procname       = "rdma_max_inline_write",
 111                 .data           = &xprt_rdma_max_inline_write,
 112                 .maxlen         = sizeof(unsigned int),
 113                 .mode           = 0644,
 114                 .proc_handler   = &proc_dointvec,
 115                 .strategy       = &sysctl_intvec,
 116         },
 117         {
 118                 .ctl_name       = CTL_UNNUMBERED,
 119                 .procname       = "rdma_inline_write_padding",
 120                 .data           = &xprt_rdma_inline_write_padding,
 121                 .maxlen         = sizeof(unsigned int),
 122                 .mode           = 0644,
 123                 .proc_handler   = &proc_dointvec_minmax,
 124                 .strategy       = &sysctl_intvec,
 125                 .extra1         = &zero,
 126                 .extra2         = &max_padding,
 127         },
 128         {
 129                 .ctl_name       = CTL_UNNUMBERED,
 130                 .procname       = "rdma_memreg_strategy",
 131                 .data           = &xprt_rdma_memreg_strategy,
 132                 .maxlen         = sizeof(unsigned int),
 133                 .mode           = 0644,
 134                 .proc_handler   = &proc_dointvec_minmax,
 135                 .strategy       = &sysctl_intvec,
 136                 .extra1         = &min_memreg,
 137                 .extra2         = &max_memreg,
 138         },
 139         {
 140                 .ctl_name       = CTL_UNNUMBERED,
 141                 .procname       = "rdma_pad_optimize",
 142                 .data           = &xprt_rdma_pad_optimize,
 143                 .maxlen         = sizeof(unsigned int),
 144                 .mode           = 0644,
 145                 .proc_handler   = &proc_dointvec,
 146         },
 147         {
 148                 .ctl_name = 0,
 149         },
 150 };
 151
 152 static ctl_table sunrpc_table[] = {
 153         {
 154                 .ctl_name       = CTL_SUNRPC,
 155                 .procname       = "sunrpc",
 156                 .mode           = 0555,
 157                 .child          = xr_tunables_table
 158         },
 159         {
 160                 .ctl_name = 0,
 161         },
 162 };
 163
 164 #endif
 165
 166 static struct rpc_xprt_ops xprt_rdma_procs;     /* forward reference */
 167
 168 static void
 169 xprt_rdma_format_addresses(struct rpc_xprt *xprt)
 170 {
 171         struct sockaddr_in *addr = (struct sockaddr_in *)
 172                                         &rpcx_to_rdmad(xprt).addr;
 173         char *buf;
 174
 175         buf = kzalloc(20, GFP_KERNEL);
 176         if (buf)
 177                 snprintf(buf, 20, NIPQUAD_FMT, NIPQUAD(addr->sin_addr.s_addr));
 178         xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
 179
 180         buf = kzalloc(8, GFP_KERNEL);
 181         if (buf)
 182                 snprintf(buf, 8, "%u", ntohs(addr->sin_port));
 183         xprt->address_strings[RPC_DISPLAY_PORT] = buf;
 184
 185         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 186
 187         buf = kzalloc(48, GFP_KERNEL);
 188         if (buf)
 189                 snprintf(buf, 48, "addr="NIPQUAD_FMT" port=%u proto=%s",
 190                         NIPQUAD(addr->sin_addr.s_addr),
 191                         ntohs(addr->sin_port), "rdma");
 192         xprt->address_strings[RPC_DISPLAY_ALL] = buf;
 193
 194         buf = kzalloc(10, GFP_KERNEL);
 195         if (buf)
 196                 snprintf(buf, 10, "%02x%02x%02x%02x",
 197                         NIPQUAD(addr->sin_addr.s_addr));
 198         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
 199
 200         buf = kzalloc(8, GFP_KERNEL);
 201         if (buf)
 202                 snprintf(buf, 8, "%4hx", ntohs(addr->sin_port));
 203         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
 204
 205         buf = kzalloc(30, GFP_KERNEL);
 206         if (buf)
 207                 snprintf(buf, 30, NIPQUAD_FMT".%u.%u",
 208                         NIPQUAD(addr->sin_addr.s_addr),
 209                         ntohs(addr->sin_port) >> 8,
 210                         ntohs(addr->sin_port) & 0xff);
 211         xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
 212
 213         /* netid */
 214         xprt->address_strings[RPC_DISPLAY_NETID] = "rdma";
 215 }
 216
 217 static void
 218 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 219 {
 220         unsigned int i;
 221
 222         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 223                 switch (i) {
 224                 case RPC_DISPLAY_PROTO:
 225                 case RPC_DISPLAY_NETID:
 226                         continue;
 227                 default:
 228                         kfree(xprt->address_strings[i]);
 229                 }
 230 }
 231
 232 static void
 233 xprt_rdma_connect_worker(struct work_struct *work)
 234 {
 235         struct rpcrdma_xprt *r_xprt =
 236                 container_of(work, struct rpcrdma_xprt, rdma_connect.work);
 237         struct rpc_xprt *xprt = &r_xprt->xprt;
 238         int rc = 0;
 239
 240         if (!xprt->shutdown) {
 241                 xprt_clear_connected(xprt);
 242
 243                 dprintk("RPC:       %s: %sconnect\n", __func__,
 244                                 r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 245                 rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 246                 if (rc)
 247                         goto out;
 248         }
 249         goto out_clear;
 250
 251 out:
 252         xprt_wake_pending_tasks(xprt, rc);
 253
 254 out_clear:
 255         dprintk("RPC:       %s: exit\n", __func__);
 256         xprt_clear_connecting(xprt);
 257 }
 258
 259 /*
 260  * xprt_rdma_destroy
 261  *
 262  * Destroy the xprt.
 263  * Free all memory associated with the object, including its own.
 264  * NOTE: none of the *destroy methods free memory for their top-level
 265  * objects, even though they may have allocated it (they do free
 266  * private memory). It's up to the caller to handle it. In this
 267  * case (RDMA transport), all structure memory is inlined with the
 268  * struct rpcrdma_xprt.
 269  */
 270 static void
 271 xprt_rdma_destroy(struct rpc_xprt *xprt)
 272 {
 273         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 274         int rc;
 275
 276         dprintk("RPC:       %s: called\n", __func__);
 277
 278         cancel_delayed_work(&r_xprt->rdma_connect);
 279         flush_scheduled_work();
 280
 281         xprt_clear_connected(xprt);
 282
 283         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 284         rc = rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 285         if (rc)
 286                 dprintk("RPC:       %s: rpcrdma_ep_destroy returned %i\n",
 287                         __func__, rc);
 288         rpcrdma_ia_close(&r_xprt->rx_ia);
 289
 290         xprt_rdma_free_addresses(xprt);
 291
 292         kfree(xprt->slot);
 293         xprt->slot = NULL;
 294         kfree(xprt);
 295
 296         dprintk("RPC:       %s: returning\n", __func__);
 297
 298         module_put(THIS_MODULE);
 299 }
 300
 301 static const struct rpc_timeout xprt_rdma_default_timeout = {
 302         .to_initval = 60 * HZ,
 303         .to_maxval = 60 * HZ,
 304 };
 305
 306 /**
 307  * xprt_setup_rdma - Set up transport to use RDMA
 308  *
 309  * @args: rpc transport arguments
 310  */
 311 static struct rpc_xprt *
 312 xprt_setup_rdma(struct xprt_create *args)
 313 {
 314         struct rpcrdma_create_data_internal cdata;
 315         struct rpc_xprt *xprt;
 316         struct rpcrdma_xprt *new_xprt;
 317         struct rpcrdma_ep *new_ep;
 318         struct sockaddr_in *sin;
 319         int rc;
 320
 321         if (args->addrlen > sizeof(xprt->addr)) {
 322                 dprintk("RPC:       %s: address too large\n", __func__);
 323                 return ERR_PTR(-EBADF);
 324         }
 325
 326         xprt = kzalloc(sizeof(struct rpcrdma_xprt), GFP_KERNEL);
 327         if (xprt == NULL) {
 328                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 329                         __func__);
 330                 return ERR_PTR(-ENOMEM);
 331         }
 332
 333         xprt->max_reqs = xprt_rdma_slot_table_entries;
 334         xprt->slot = kcalloc(xprt->max_reqs,
 335                                 sizeof(struct rpc_rqst), GFP_KERNEL);
 336         if (xprt->slot == NULL) {
 337                 dprintk("RPC:       %s: couldn't allocate %d slots\n",
 338                         __func__, xprt->max_reqs);
 339                 kfree(xprt);
 340                 return ERR_PTR(-ENOMEM);
 341         }
 342
 343         /* 60 second timeout, no retries */
 344         xprt->timeout = &xprt_rdma_default_timeout;
 345         xprt->bind_timeout = (60U * HZ);
 346         xprt->connect_timeout = (60U * HZ);
 347         xprt->reestablish_timeout = (5U * HZ);
 348         xprt->idle_timeout = (5U * 60 * HZ);
 349
 350         xprt->resvport = 0;             /* privileged port not needed */
 351         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 352         xprt->max_payload = RPCRDMA_MAX_DATA_SEGS * PAGE_SIZE;
 353         xprt->ops = &xprt_rdma_procs;
 354
 355         /*
 356          * Set up RDMA-specific connect data.
 357          */
 358
 359         /* Put server RDMA address in local cdata */
 360         memcpy(&cdata.addr, args->dstaddr, args->addrlen);
 361
 362         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 363          * address, for any side protocols which peek at it */
 364         xprt->prot = IPPROTO_TCP;
 365         xprt->addrlen = args->addrlen;
 366         memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
 367
 368         sin = (struct sockaddr_in *)&cdata.addr;
 369         if (ntohs(sin->sin_port) != 0)
 370                 xprt_set_bound(xprt);
 371
 372         dprintk("RPC:       %s: %u.%u.%u.%u:%u\n", __func__,
 373                         NIPQUAD(sin->sin_addr.s_addr), ntohs(sin->sin_port));
 374
 375         /* Set max requests */
 376         cdata.max_requests = xprt->max_reqs;
 377
 378         /* Set some length limits */
 379         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 380         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 381
 382         cdata.inline_wsize = xprt_rdma_max_inline_write;
 383         if (cdata.inline_wsize > cdata.wsize)
 384                 cdata.inline_wsize = cdata.wsize;
 385
 386         cdata.inline_rsize = xprt_rdma_max_inline_read;
 387         if (cdata.inline_rsize > cdata.rsize)
 388                 cdata.inline_rsize = cdata.rsize;
 389
 390         cdata.padding = xprt_rdma_inline_write_padding;
 391
 392         /*
 393          * Create new transport instance, which includes initialized
 394          *  o ia
 395          *  o endpoint
 396          *  o buffers
 397          */
 398
 399         new_xprt = rpcx_to_rdmax(xprt);
 400
 401         rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
 402                                 xprt_rdma_memreg_strategy);
 403         if (rc)
 404                 goto out1;
 405
 406         /*
 407          * initialize and create ep
 408          */
 409         new_xprt->rx_data = cdata;
 410         new_ep = &new_xprt->rx_ep;
 411         new_ep->rep_remote_addr = cdata.addr;
 412
 413         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 414                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 415         if (rc)
 416                 goto out2;
 417
 418         /*
 419          * Allocate pre-registered send and receive buffers for headers and
 420          * any inline data. Also specify any padding which will be provided
 421          * from a preregistered zero buffer.
 422          */
 423         rc = rpcrdma_buffer_create(&new_xprt->rx_buf, new_ep, &new_xprt->rx_ia,
 424                                 &new_xprt->rx_data);
 425         if (rc)
 426                 goto out3;
 427
 428         /*
 429          * Register a callback for connection events. This is necessary because
 430          * connection loss notification is async. We also catch connection loss
 431          * when reaping receives.
 432          */
 433         INIT_DELAYED_WORK(&new_xprt->rdma_connect, xprt_rdma_connect_worker);
 434         new_ep->rep_func = rpcrdma_conn_func;
 435         new_ep->rep_xprt = xprt;
 436
 437         xprt_rdma_format_addresses(xprt);
 438
 439         if (!try_module_get(THIS_MODULE))
 440                 goto out4;
 441
 442         return xprt;
 443
 444 out4:
 445         xprt_rdma_free_addresses(xprt);
 446         rc = -EINVAL;
 447 out3:
 448         (void) rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 449 out2:
 450         rpcrdma_ia_close(&new_xprt->rx_ia);
 451 out1:
 452         kfree(xprt->slot);
 453         kfree(xprt);
 454         return ERR_PTR(rc);
 455 }
 456
 457 /*
 458  * Close a connection, during shutdown or timeout/reconnect
 459  */
 460 static void
 461 xprt_rdma_close(struct rpc_xprt *xprt)
 462 {
 463         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 464
 465         dprintk("RPC:       %s: closing\n", __func__);
 466         if (r_xprt->rx_ep.rep_connected > 0)
 467                 xprt->reestablish_timeout = 0;
 468         xprt_disconnect_done(xprt);
 469         (void) rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 470 }
 471
 472 static void
 473 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 474 {
 475         struct sockaddr_in *sap;
 476
 477         sap = (struct sockaddr_in *)&xprt->addr;
 478         sap->sin_port = htons(port);
 479         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 480         sap->sin_port = htons(port);
 481         dprintk("RPC:       %s: %u\n", __func__, port);
 482 }
 483
 484 static void
 485 xprt_rdma_connect(struct rpc_task *task)
 486 {
 487         struct rpc_xprt *xprt = (struct rpc_xprt *)task->tk_xprt;
 488         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 489
 490         if (!xprt_test_and_set_connecting(xprt)) {
 491                 if (r_xprt->rx_ep.rep_connected != 0) {
 492                         /* Reconnect */
 493                         schedule_delayed_work(&r_xprt->rdma_connect,
 494                                 xprt->reestablish_timeout);
 495                         xprt->reestablish_timeout <<= 1;
 496                         if (xprt->reestablish_timeout > (30 * HZ))
 497                                 xprt->reestablish_timeout = (30 * HZ);
 498                         else if (xprt->reestablish_timeout < (5 * HZ))
 499                                 xprt->reestablish_timeout = (5 * HZ);
 500                 } else {
 501                         schedule_delayed_work(&r_xprt->rdma_connect, 0);
 502                         if (!RPC_IS_ASYNC(task))
 503                                 flush_scheduled_work();
 504                 }
 505         }
 506 }
 507
 508 static int
 509 xprt_rdma_reserve_xprt(struct rpc_task *task)
 510 {
 511         struct rpc_xprt *xprt = task->tk_xprt;
 512         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 513         int credits = atomic_read(&r_xprt->rx_buf.rb_credits);
 514
 515         /* == RPC_CWNDSCALE @ init, but *after* setup */
 516         if (r_xprt->rx_buf.rb_cwndscale == 0UL) {
 517                 r_xprt->rx_buf.rb_cwndscale = xprt->cwnd;
 518                 dprintk("RPC:       %s: cwndscale %lu\n", __func__,
 519                         r_xprt->rx_buf.rb_cwndscale);
 520                 BUG_ON(r_xprt->rx_buf.rb_cwndscale <= 0);
 521         }
 522         xprt->cwnd = credits * r_xprt->rx_buf.rb_cwndscale;
 523         return xprt_reserve_xprt_cong(task);
 524 }
 525
 526 /*
 527  * The RDMA allocate/free functions need the task structure as a place
 528  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 529  * sequence. For this reason, the recv buffers are attached to send
 530  * buffers for portions of the RPC. Note that the RPC layer allocates
 531  * both send and receive buffers in the same call. We may register
 532  * the receive buffer portion when using reply chunks.
 533  */
 534 static void *
 535 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 536 {
 537         struct rpc_xprt *xprt = task->tk_xprt;
 538         struct rpcrdma_req *req, *nreq;
 539
 540         req = rpcrdma_buffer_get(&rpcx_to_rdmax(xprt)->rx_buf);
 541         BUG_ON(NULL == req);
 542
 543         if (size > req->rl_size) {
 544                 dprintk("RPC:       %s: size %zd too large for buffer[%zd]: "
 545                         "prog %d vers %d proc %d\n",
 546                         __func__, size, req->rl_size,
 547                         task->tk_client->cl_prog, task->tk_client->cl_vers,
 548                         task->tk_msg.rpc_proc->p_proc);
 549                 /*
 550                  * Outgoing length shortage. Our inline write max must have
 551                  * been configured to perform direct i/o.
 552                  *
 553                  * This is therefore a large metadata operation, and the
 554                  * allocate call was made on the maximum possible message,
 555                  * e.g. containing long filename(s) or symlink data. In
 556                  * fact, while these metadata operations *might* carry
 557                  * large outgoing payloads, they rarely *do*. However, we
 558                  * have to commit to the request here, so reallocate and
 559                  * register it now. The data path will never require this
 560                  * reallocation.
 561                  *
 562                  * If the allocation or registration fails, the RPC framework
 563                  * will (doggedly) retry.
 564                  */
 565                 if (rpcx_to_rdmax(xprt)->rx_ia.ri_memreg_strategy ==
 566                                 RPCRDMA_BOUNCEBUFFERS) {
 567                         /* forced to "pure inline" */
 568                         dprintk("RPC:       %s: too much data (%zd) for inline "
 569                                         "(r/w max %d/%d)\n", __func__, size,
 570                                         rpcx_to_rdmad(xprt).inline_rsize,
 571                                         rpcx_to_rdmad(xprt).inline_wsize);
 572                         size = req->rl_size;
 573                         rpc_exit(task, -EIO);           /* fail the operation */
 574                         rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
 575                         goto out;
 576                 }
 577                 if (task->tk_flags & RPC_TASK_SWAPPER)
 578                         nreq = kmalloc(sizeof *req + size, GFP_ATOMIC);
 579                 else
 580                         nreq = kmalloc(sizeof *req + size, GFP_NOFS);
 581                 if (nreq == NULL)
 582                         goto outfail;
 583
 584                 if (rpcrdma_register_internal(&rpcx_to_rdmax(xprt)->rx_ia,
 585                                 nreq->rl_base, size + sizeof(struct rpcrdma_req)
 586                                 - offsetof(struct rpcrdma_req, rl_base),
 587                                 &nreq->rl_handle, &nreq->rl_iov)) {
 588                         kfree(nreq);
 589                         goto outfail;
 590                 }
 591                 rpcx_to_rdmax(xprt)->rx_stats.hardway_register_count += size;
 592                 nreq->rl_size = size;
 593                 nreq->rl_niovs = 0;
 594                 nreq->rl_nchunks = 0;
 595                 nreq->rl_buffer = (struct rpcrdma_buffer *)req;
 596                 nreq->rl_reply = req->rl_reply;
 597                 memcpy(nreq->rl_segments,
 598                         req->rl_segments, sizeof nreq->rl_segments);
 599                 /* flag the swap with an unused field */
 600                 nreq->rl_iov.length = 0;
 601                 req->rl_reply = NULL;
 602                 req = nreq;
 603         }
 604         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 605 out:
 606         req->rl_connect_cookie = 0;     /* our reserved value */
 607         return req->rl_xdr_buf;
 608
 609 outfail:
 610         rpcrdma_buffer_put(req);
 611         rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
 612         return NULL;
 613 }
 614
 615 /*
 616  * This function returns all RDMA resources to the pool.
 617  */
 618 static void
 619 xprt_rdma_free(void *buffer)
 620 {
 621         struct rpcrdma_req *req;
 622         struct rpcrdma_xprt *r_xprt;
 623         struct rpcrdma_rep *rep;
 624         int i;
 625
 626         if (buffer == NULL)
 627                 return;
 628
 629         req = container_of(buffer, struct rpcrdma_req, rl_xdr_buf[0]);
 630         if (req->rl_iov.length == 0) {  /* see allocate above */
 631                 r_xprt = container_of(((struct rpcrdma_req *) req->rl_buffer)->rl_buffer,
 632                                       struct rpcrdma_xprt, rx_buf);
 633         } else
 634                 r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 635         rep = req->rl_reply;
 636
 637         dprintk("RPC:       %s: called on 0x%p%s\n",
 638                 __func__, rep, (rep && rep->rr_func) ? " (with waiter)" : "");
 639
 640         /*
 641          * Finish the deregistration. When using mw bind, this was
 642          * begun in rpcrdma_reply_handler(). In all other modes, we
 643          * do it here, in thread context. The process is considered
 644          * complete when the rr_func vector becomes NULL - this
 645          * was put in place during rpcrdma_reply_handler() - the wait
 646          * call below will not block if the dereg is "done". If
 647          * interrupted, our framework will clean up.
 648          */
 649         for (i = 0; req->rl_nchunks;) {
 650                 --req->rl_nchunks;
 651                 i += rpcrdma_deregister_external(
 652                         &req->rl_segments[i], r_xprt, NULL);
 653         }
 654
 655         if (rep && wait_event_interruptible(rep->rr_unbind, !rep->rr_func)) {
 656                 rep->rr_func = NULL;    /* abandon the callback */
 657                 req->rl_reply = NULL;
 658         }
 659
 660         if (req->rl_iov.length == 0) {  /* see allocate above */
 661                 struct rpcrdma_req *oreq = (struct rpcrdma_req *)req->rl_buffer;
 662                 oreq->rl_reply = req->rl_reply;
 663                 (void) rpcrdma_deregister_internal(&r_xprt->rx_ia,
 664                                                    req->rl_handle,
 665                                                    &req->rl_iov);
 666                 kfree(req);
 667                 req = oreq;
 668         }
 669
 670         /* Put back request+reply buffers */
 671         rpcrdma_buffer_put(req);
 672 }
 673
 674 /*
 675  * send_request invokes the meat of RPC RDMA. It must do the following:
 676  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 677  *      putting a header in front of data, and creating IOVs for RDMA
 678  *      from those in the request.
 679  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 680  *  3.  Post a recv message to set up asynch completion, then send
 681  *      the request (rpcrdma_ep_post).
 682  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 683  */
 684
 685 static int
 686 xprt_rdma_send_request(struct rpc_task *task)
 687 {
 688         struct rpc_rqst *rqst = task->tk_rqstp;
 689         struct rpc_xprt *xprt = task->tk_xprt;
 690         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 691         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 692
 693         /* marshal the send itself */
 694         if (req->rl_niovs == 0 && rpcrdma_marshal_req(rqst) != 0) {
 695                 r_xprt->rx_stats.failed_marshal_count++;
 696                 dprintk("RPC:       %s: rpcrdma_marshal_req failed\n",
 697                         __func__);
 698                 return -EIO;
 699         }
 700
 701         if (req->rl_reply == NULL)              /* e.g. reconnection */
 702                 rpcrdma_recv_buffer_get(req);
 703
 704         if (req->rl_reply) {
 705                 req->rl_reply->rr_func = rpcrdma_reply_handler;
 706                 /* this need only be done once, but... */
 707                 req->rl_reply->rr_xprt = xprt;
 708         }
 709
 710         /* Must suppress retransmit to maintain credits */
 711         if (req->rl_connect_cookie == xprt->connect_cookie)
 712                 goto drop_connection;
 713         req->rl_connect_cookie = xprt->connect_cookie;
 714
 715         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 716                 goto drop_connection;
 717
 718         task->tk_bytes_sent += rqst->rq_snd_buf.len;
 719         rqst->rq_bytes_sent = 0;
 720         return 0;
 721
 722 drop_connection:
 723         xprt_disconnect_done(xprt);
 724         return -ENOTCONN;       /* implies disconnect */
 725 }
 726
 727 static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 728 {
 729         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 730         long idle_time = 0;
 731
 732         if (xprt_connected(xprt))
 733                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 734
 735         seq_printf(seq,
 736           "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
 737           "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
 738
 739            0,   /* need a local port? */
 740            xprt->stat.bind_count,
 741            xprt->stat.connect_count,
 742            xprt->stat.connect_time,
 743            idle_time,
 744            xprt->stat.sends,
 745            xprt->stat.recvs,
 746            xprt->stat.bad_xids,
 747            xprt->stat.req_u,
 748            xprt->stat.bklog_u,
 749
 750            r_xprt->rx_stats.read_chunk_count,
 751            r_xprt->rx_stats.write_chunk_count,
 752            r_xprt->rx_stats.reply_chunk_count,
 753            r_xprt->rx_stats.total_rdma_request,
 754            r_xprt->rx_stats.total_rdma_reply,
 755            r_xprt->rx_stats.pullup_copy_count,
 756            r_xprt->rx_stats.fixup_copy_count,
 757            r_xprt->rx_stats.hardway_register_count,
 758            r_xprt->rx_stats.failed_marshal_count,
 759            r_xprt->rx_stats.bad_reply_count);
 760 }
 761
 762 /*
 763  * Plumbing for rpc transport switch and kernel module
 764  */
 765
 766 static struct rpc_xprt_ops xprt_rdma_procs = {
 767         .reserve_xprt           = xprt_rdma_reserve_xprt,
 768         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 769         .release_request        = xprt_release_rqst_cong,       /* ditto */
 770         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 771         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 772         .set_port               = xprt_rdma_set_port,
 773         .connect                = xprt_rdma_connect,
 774         .buf_alloc              = xprt_rdma_allocate,
 775         .buf_free               = xprt_rdma_free,
 776         .send_request           = xprt_rdma_send_request,
 777         .close                  = xprt_rdma_close,
 778         .destroy                = xprt_rdma_destroy,
 779         .print_stats            = xprt_rdma_print_stats
 780 };
 781
 782 static struct xprt_class xprt_rdma = {
 783         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 784         .name                   = "rdma",
 785         .owner                  = THIS_MODULE,
 786         .ident                  = XPRT_TRANSPORT_RDMA,
 787         .setup                  = xprt_setup_rdma,
 788 };
 789
 790 static void __exit xprt_rdma_cleanup(void)
 791 {
 792         int rc;
 793
 794         dprintk(KERN_INFO "RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 795 #ifdef RPC_DEBUG
 796         if (sunrpc_table_header) {
 797                 unregister_sysctl_table(sunrpc_table_header);
 798                 sunrpc_table_header = NULL;
 799         }
 800 #endif
 801         rc = xprt_unregister_transport(&xprt_rdma);
 802         if (rc)
 803                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 804                         __func__, rc);
 805 }
 806
 807 static int __init xprt_rdma_init(void)
 808 {
 809         int rc;
 810
 811         rc = xprt_register_transport(&xprt_rdma);
 812
 813         if (rc)
 814                 return rc;
 815
 816         dprintk(KERN_INFO "RPCRDMA Module Init, register RPC RDMA transport\n");
 817
 818         dprintk(KERN_INFO "Defaults:\n");
 819         dprintk(KERN_INFO "\tSlots %d\n"
 820                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 821                 xprt_rdma_slot_table_entries,
 822                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 823         dprintk(KERN_INFO "\tPadding %d\n\tMemreg %d\n",
 824                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 825
 826 #ifdef RPC_DEBUG
 827         if (!sunrpc_table_header)
 828                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 829 #endif
 830         return 0;
 831 }
 832
 833 module_init(xprt_rdma_init);
 834 module_exit(xprt_rdma_cleanup);