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   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 *sap = (struct sockaddr *)
 172                                         &rpcx_to_rdmad(xprt).addr;
 173         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 174         char buf[64];
 175
 176         (void)rpc_ntop(sap, buf, sizeof(buf));
 177         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 178
 179         (void)snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 180         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 181
 182         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 183
 184         (void)snprintf(buf, sizeof(buf), "%02x%02x%02x%02x",
 185                                 NIPQUAD(sin->sin_addr.s_addr));
 186         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 187
 188         (void)snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 189         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 190
 191         /* netid */
 192         xprt->address_strings[RPC_DISPLAY_NETID] = "rdma";
 193 }
 194
 195 static void
 196 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 197 {
 198         unsigned int i;
 199
 200         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 201                 switch (i) {
 202                 case RPC_DISPLAY_PROTO:
 203                 case RPC_DISPLAY_NETID:
 204                         continue;
 205                 default:
 206                         kfree(xprt->address_strings[i]);
 207                 }
 208 }
 209
 210 static void
 211 xprt_rdma_connect_worker(struct work_struct *work)
 212 {
 213         struct rpcrdma_xprt *r_xprt =
 214                 container_of(work, struct rpcrdma_xprt, rdma_connect.work);
 215         struct rpc_xprt *xprt = &r_xprt->xprt;
 216         int rc = 0;
 217
 218         if (!xprt->shutdown) {
 219                 xprt_clear_connected(xprt);
 220
 221                 dprintk("RPC:       %s: %sconnect\n", __func__,
 222                                 r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 223                 rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 224                 if (rc)
 225                         goto out;
 226         }
 227         goto out_clear;
 228
 229 out:
 230         xprt_wake_pending_tasks(xprt, rc);
 231
 232 out_clear:
 233         dprintk("RPC:       %s: exit\n", __func__);
 234         xprt_clear_connecting(xprt);
 235 }
 236
 237 /*
 238  * xprt_rdma_destroy
 239  *
 240  * Destroy the xprt.
 241  * Free all memory associated with the object, including its own.
 242  * NOTE: none of the *destroy methods free memory for their top-level
 243  * objects, even though they may have allocated it (they do free
 244  * private memory). It's up to the caller to handle it. In this
 245  * case (RDMA transport), all structure memory is inlined with the
 246  * struct rpcrdma_xprt.
 247  */
 248 static void
 249 xprt_rdma_destroy(struct rpc_xprt *xprt)
 250 {
 251         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 252         int rc;
 253
 254         dprintk("RPC:       %s: called\n", __func__);
 255
 256         cancel_delayed_work(&r_xprt->rdma_connect);
 257         flush_scheduled_work();
 258
 259         xprt_clear_connected(xprt);
 260
 261         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 262         rc = rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 263         if (rc)
 264                 dprintk("RPC:       %s: rpcrdma_ep_destroy returned %i\n",
 265                         __func__, rc);
 266         rpcrdma_ia_close(&r_xprt->rx_ia);
 267
 268         xprt_rdma_free_addresses(xprt);
 269
 270         kfree(xprt->slot);
 271         xprt->slot = NULL;
 272         kfree(xprt);
 273
 274         dprintk("RPC:       %s: returning\n", __func__);
 275
 276         module_put(THIS_MODULE);
 277 }
 278
 279 static const struct rpc_timeout xprt_rdma_default_timeout = {
 280         .to_initval = 60 * HZ,
 281         .to_maxval = 60 * HZ,
 282 };
 283
 284 /**
 285  * xprt_setup_rdma - Set up transport to use RDMA
 286  *
 287  * @args: rpc transport arguments
 288  */
 289 static struct rpc_xprt *
 290 xprt_setup_rdma(struct xprt_create *args)
 291 {
 292         struct rpcrdma_create_data_internal cdata;
 293         struct rpc_xprt *xprt;
 294         struct rpcrdma_xprt *new_xprt;
 295         struct rpcrdma_ep *new_ep;
 296         struct sockaddr_in *sin;
 297         int rc;
 298
 299         if (args->addrlen > sizeof(xprt->addr)) {
 300                 dprintk("RPC:       %s: address too large\n", __func__);
 301                 return ERR_PTR(-EBADF);
 302         }
 303
 304         xprt = kzalloc(sizeof(struct rpcrdma_xprt), GFP_KERNEL);
 305         if (xprt == NULL) {
 306                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 307                         __func__);
 308                 return ERR_PTR(-ENOMEM);
 309         }
 310
 311         xprt->max_reqs = xprt_rdma_slot_table_entries;
 312         xprt->slot = kcalloc(xprt->max_reqs,
 313                                 sizeof(struct rpc_rqst), GFP_KERNEL);
 314         if (xprt->slot == NULL) {
 315                 dprintk("RPC:       %s: couldn't allocate %d slots\n",
 316                         __func__, xprt->max_reqs);
 317                 kfree(xprt);
 318                 return ERR_PTR(-ENOMEM);
 319         }
 320
 321         /* 60 second timeout, no retries */
 322         xprt->timeout = &xprt_rdma_default_timeout;
 323         xprt->bind_timeout = (60U * HZ);
 324         xprt->connect_timeout = (60U * HZ);
 325         xprt->reestablish_timeout = (5U * HZ);
 326         xprt->idle_timeout = (5U * 60 * HZ);
 327
 328         xprt->resvport = 0;             /* privileged port not needed */
 329         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 330         xprt->max_payload = RPCRDMA_MAX_DATA_SEGS * PAGE_SIZE;
 331         xprt->ops = &xprt_rdma_procs;
 332
 333         /*
 334          * Set up RDMA-specific connect data.
 335          */
 336
 337         /* Put server RDMA address in local cdata */
 338         memcpy(&cdata.addr, args->dstaddr, args->addrlen);
 339
 340         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 341          * address, for any side protocols which peek at it */
 342         xprt->prot = IPPROTO_TCP;
 343         xprt->addrlen = args->addrlen;
 344         memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
 345
 346         sin = (struct sockaddr_in *)&cdata.addr;
 347         if (ntohs(sin->sin_port) != 0)
 348                 xprt_set_bound(xprt);
 349
 350         dprintk("RPC:       %s: %pI4:%u\n",
 351                 __func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
 352
 353         /* Set max requests */
 354         cdata.max_requests = xprt->max_reqs;
 355
 356         /* Set some length limits */
 357         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 358         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 359
 360         cdata.inline_wsize = xprt_rdma_max_inline_write;
 361         if (cdata.inline_wsize > cdata.wsize)
 362                 cdata.inline_wsize = cdata.wsize;
 363
 364         cdata.inline_rsize = xprt_rdma_max_inline_read;
 365         if (cdata.inline_rsize > cdata.rsize)
 366                 cdata.inline_rsize = cdata.rsize;
 367
 368         cdata.padding = xprt_rdma_inline_write_padding;
 369
 370         /*
 371          * Create new transport instance, which includes initialized
 372          *  o ia
 373          *  o endpoint
 374          *  o buffers
 375          */
 376
 377         new_xprt = rpcx_to_rdmax(xprt);
 378
 379         rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
 380                                 xprt_rdma_memreg_strategy);
 381         if (rc)
 382                 goto out1;
 383
 384         /*
 385          * initialize and create ep
 386          */
 387         new_xprt->rx_data = cdata;
 388         new_ep = &new_xprt->rx_ep;
 389         new_ep->rep_remote_addr = cdata.addr;
 390
 391         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 392                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 393         if (rc)
 394                 goto out2;
 395
 396         /*
 397          * Allocate pre-registered send and receive buffers for headers and
 398          * any inline data. Also specify any padding which will be provided
 399          * from a preregistered zero buffer.
 400          */
 401         rc = rpcrdma_buffer_create(&new_xprt->rx_buf, new_ep, &new_xprt->rx_ia,
 402                                 &new_xprt->rx_data);
 403         if (rc)
 404                 goto out3;
 405
 406         /*
 407          * Register a callback for connection events. This is necessary because
 408          * connection loss notification is async. We also catch connection loss
 409          * when reaping receives.
 410          */
 411         INIT_DELAYED_WORK(&new_xprt->rdma_connect, xprt_rdma_connect_worker);
 412         new_ep->rep_func = rpcrdma_conn_func;
 413         new_ep->rep_xprt = xprt;
 414
 415         xprt_rdma_format_addresses(xprt);
 416
 417         if (!try_module_get(THIS_MODULE))
 418                 goto out4;
 419
 420         return xprt;
 421
 422 out4:
 423         xprt_rdma_free_addresses(xprt);
 424         rc = -EINVAL;
 425 out3:
 426         (void) rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 427 out2:
 428         rpcrdma_ia_close(&new_xprt->rx_ia);
 429 out1:
 430         kfree(xprt->slot);
 431         kfree(xprt);
 432         return ERR_PTR(rc);
 433 }
 434
 435 /*
 436  * Close a connection, during shutdown or timeout/reconnect
 437  */
 438 static void
 439 xprt_rdma_close(struct rpc_xprt *xprt)
 440 {
 441         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 442
 443         dprintk("RPC:       %s: closing\n", __func__);
 444         if (r_xprt->rx_ep.rep_connected > 0)
 445                 xprt->reestablish_timeout = 0;
 446         xprt_disconnect_done(xprt);
 447         (void) rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 448 }
 449
 450 static void
 451 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 452 {
 453         struct sockaddr_in *sap;
 454
 455         sap = (struct sockaddr_in *)&xprt->addr;
 456         sap->sin_port = htons(port);
 457         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 458         sap->sin_port = htons(port);
 459         dprintk("RPC:       %s: %u\n", __func__, port);
 460 }
 461
 462 static void
 463 xprt_rdma_connect(struct rpc_task *task)
 464 {
 465         struct rpc_xprt *xprt = (struct rpc_xprt *)task->tk_xprt;
 466         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 467
 468         if (!xprt_test_and_set_connecting(xprt)) {
 469                 if (r_xprt->rx_ep.rep_connected != 0) {
 470                         /* Reconnect */
 471                         schedule_delayed_work(&r_xprt->rdma_connect,
 472                                 xprt->reestablish_timeout);
 473                         xprt->reestablish_timeout <<= 1;
 474                         if (xprt->reestablish_timeout > (30 * HZ))
 475                                 xprt->reestablish_timeout = (30 * HZ);
 476                         else if (xprt->reestablish_timeout < (5 * HZ))
 477                                 xprt->reestablish_timeout = (5 * HZ);
 478                 } else {
 479                         schedule_delayed_work(&r_xprt->rdma_connect, 0);
 480                         if (!RPC_IS_ASYNC(task))
 481                                 flush_scheduled_work();
 482                 }
 483         }
 484 }
 485
 486 static int
 487 xprt_rdma_reserve_xprt(struct rpc_task *task)
 488 {
 489         struct rpc_xprt *xprt = task->tk_xprt;
 490         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 491         int credits = atomic_read(&r_xprt->rx_buf.rb_credits);
 492
 493         /* == RPC_CWNDSCALE @ init, but *after* setup */
 494         if (r_xprt->rx_buf.rb_cwndscale == 0UL) {
 495                 r_xprt->rx_buf.rb_cwndscale = xprt->cwnd;
 496                 dprintk("RPC:       %s: cwndscale %lu\n", __func__,
 497                         r_xprt->rx_buf.rb_cwndscale);
 498                 BUG_ON(r_xprt->rx_buf.rb_cwndscale <= 0);
 499         }
 500         xprt->cwnd = credits * r_xprt->rx_buf.rb_cwndscale;
 501         return xprt_reserve_xprt_cong(task);
 502 }
 503
 504 /*
 505  * The RDMA allocate/free functions need the task structure as a place
 506  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 507  * sequence. For this reason, the recv buffers are attached to send
 508  * buffers for portions of the RPC. Note that the RPC layer allocates
 509  * both send and receive buffers in the same call. We may register
 510  * the receive buffer portion when using reply chunks.
 511  */
 512 static void *
 513 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 514 {
 515         struct rpc_xprt *xprt = task->tk_xprt;
 516         struct rpcrdma_req *req, *nreq;
 517
 518         req = rpcrdma_buffer_get(&rpcx_to_rdmax(xprt)->rx_buf);
 519         BUG_ON(NULL == req);
 520
 521         if (size > req->rl_size) {
 522                 dprintk("RPC:       %s: size %zd too large for buffer[%zd]: "
 523                         "prog %d vers %d proc %d\n",
 524                         __func__, size, req->rl_size,
 525                         task->tk_client->cl_prog, task->tk_client->cl_vers,
 526                         task->tk_msg.rpc_proc->p_proc);
 527                 /*
 528                  * Outgoing length shortage. Our inline write max must have
 529                  * been configured to perform direct i/o.
 530                  *
 531                  * This is therefore a large metadata operation, and the
 532                  * allocate call was made on the maximum possible message,
 533                  * e.g. containing long filename(s) or symlink data. In
 534                  * fact, while these metadata operations *might* carry
 535                  * large outgoing payloads, they rarely *do*. However, we
 536                  * have to commit to the request here, so reallocate and
 537                  * register it now. The data path will never require this
 538                  * reallocation.
 539                  *
 540                  * If the allocation or registration fails, the RPC framework
 541                  * will (doggedly) retry.
 542                  */
 543                 if (rpcx_to_rdmax(xprt)->rx_ia.ri_memreg_strategy ==
 544                                 RPCRDMA_BOUNCEBUFFERS) {
 545                         /* forced to "pure inline" */
 546                         dprintk("RPC:       %s: too much data (%zd) for inline "
 547                                         "(r/w max %d/%d)\n", __func__, size,
 548                                         rpcx_to_rdmad(xprt).inline_rsize,
 549                                         rpcx_to_rdmad(xprt).inline_wsize);
 550                         size = req->rl_size;
 551                         rpc_exit(task, -EIO);           /* fail the operation */
 552                         rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
 553                         goto out;
 554                 }
 555                 if (task->tk_flags & RPC_TASK_SWAPPER)
 556                         nreq = kmalloc(sizeof *req + size, GFP_ATOMIC);
 557                 else
 558                         nreq = kmalloc(sizeof *req + size, GFP_NOFS);
 559                 if (nreq == NULL)
 560                         goto outfail;
 561
 562                 if (rpcrdma_register_internal(&rpcx_to_rdmax(xprt)->rx_ia,
 563                                 nreq->rl_base, size + sizeof(struct rpcrdma_req)
 564                                 - offsetof(struct rpcrdma_req, rl_base),
 565                                 &nreq->rl_handle, &nreq->rl_iov)) {
 566                         kfree(nreq);
 567                         goto outfail;
 568                 }
 569                 rpcx_to_rdmax(xprt)->rx_stats.hardway_register_count += size;
 570                 nreq->rl_size = size;
 571                 nreq->rl_niovs = 0;
 572                 nreq->rl_nchunks = 0;
 573                 nreq->rl_buffer = (struct rpcrdma_buffer *)req;
 574                 nreq->rl_reply = req->rl_reply;
 575                 memcpy(nreq->rl_segments,
 576                         req->rl_segments, sizeof nreq->rl_segments);
 577                 /* flag the swap with an unused field */
 578                 nreq->rl_iov.length = 0;
 579                 req->rl_reply = NULL;
 580                 req = nreq;
 581         }
 582         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 583 out:
 584         req->rl_connect_cookie = 0;     /* our reserved value */
 585         return req->rl_xdr_buf;
 586
 587 outfail:
 588         rpcrdma_buffer_put(req);
 589         rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
 590         return NULL;
 591 }
 592
 593 /*
 594  * This function returns all RDMA resources to the pool.
 595  */
 596 static void
 597 xprt_rdma_free(void *buffer)
 598 {
 599         struct rpcrdma_req *req;
 600         struct rpcrdma_xprt *r_xprt;
 601         struct rpcrdma_rep *rep;
 602         int i;
 603
 604         if (buffer == NULL)
 605                 return;
 606
 607         req = container_of(buffer, struct rpcrdma_req, rl_xdr_buf[0]);
 608         if (req->rl_iov.length == 0) {  /* see allocate above */
 609                 r_xprt = container_of(((struct rpcrdma_req *) req->rl_buffer)->rl_buffer,
 610                                       struct rpcrdma_xprt, rx_buf);
 611         } else
 612                 r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 613         rep = req->rl_reply;
 614
 615         dprintk("RPC:       %s: called on 0x%p%s\n",
 616                 __func__, rep, (rep && rep->rr_func) ? " (with waiter)" : "");
 617
 618         /*
 619          * Finish the deregistration. When using mw bind, this was
 620          * begun in rpcrdma_reply_handler(). In all other modes, we
 621          * do it here, in thread context. The process is considered
 622          * complete when the rr_func vector becomes NULL - this
 623          * was put in place during rpcrdma_reply_handler() - the wait
 624          * call below will not block if the dereg is "done". If
 625          * interrupted, our framework will clean up.
 626          */
 627         for (i = 0; req->rl_nchunks;) {
 628                 --req->rl_nchunks;
 629                 i += rpcrdma_deregister_external(
 630                         &req->rl_segments[i], r_xprt, NULL);
 631         }
 632
 633         if (rep && wait_event_interruptible(rep->rr_unbind, !rep->rr_func)) {
 634                 rep->rr_func = NULL;    /* abandon the callback */
 635                 req->rl_reply = NULL;
 636         }
 637
 638         if (req->rl_iov.length == 0) {  /* see allocate above */
 639                 struct rpcrdma_req *oreq = (struct rpcrdma_req *)req->rl_buffer;
 640                 oreq->rl_reply = req->rl_reply;
 641                 (void) rpcrdma_deregister_internal(&r_xprt->rx_ia,
 642                                                    req->rl_handle,
 643                                                    &req->rl_iov);
 644                 kfree(req);
 645                 req = oreq;
 646         }
 647
 648         /* Put back request+reply buffers */
 649         rpcrdma_buffer_put(req);
 650 }
 651
 652 /*
 653  * send_request invokes the meat of RPC RDMA. It must do the following:
 654  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 655  *      putting a header in front of data, and creating IOVs for RDMA
 656  *      from those in the request.
 657  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 658  *  3.  Post a recv message to set up asynch completion, then send
 659  *      the request (rpcrdma_ep_post).
 660  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 661  */
 662
 663 static int
 664 xprt_rdma_send_request(struct rpc_task *task)
 665 {
 666         struct rpc_rqst *rqst = task->tk_rqstp;
 667         struct rpc_xprt *xprt = task->tk_xprt;
 668         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 669         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 670
 671         /* marshal the send itself */
 672         if (req->rl_niovs == 0 && rpcrdma_marshal_req(rqst) != 0) {
 673                 r_xprt->rx_stats.failed_marshal_count++;
 674                 dprintk("RPC:       %s: rpcrdma_marshal_req failed\n",
 675                         __func__);
 676                 return -EIO;
 677         }
 678
 679         if (req->rl_reply == NULL)              /* e.g. reconnection */
 680                 rpcrdma_recv_buffer_get(req);
 681
 682         if (req->rl_reply) {
 683                 req->rl_reply->rr_func = rpcrdma_reply_handler;
 684                 /* this need only be done once, but... */
 685                 req->rl_reply->rr_xprt = xprt;
 686         }
 687
 688         /* Must suppress retransmit to maintain credits */
 689         if (req->rl_connect_cookie == xprt->connect_cookie)
 690                 goto drop_connection;
 691         req->rl_connect_cookie = xprt->connect_cookie;
 692
 693         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 694                 goto drop_connection;
 695
 696         task->tk_bytes_sent += rqst->rq_snd_buf.len;
 697         rqst->rq_bytes_sent = 0;
 698         return 0;
 699
 700 drop_connection:
 701         xprt_disconnect_done(xprt);
 702         return -ENOTCONN;       /* implies disconnect */
 703 }
 704
 705 static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 706 {
 707         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 708         long idle_time = 0;
 709
 710         if (xprt_connected(xprt))
 711                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 712
 713         seq_printf(seq,
 714           "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
 715           "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
 716
 717            0,   /* need a local port? */
 718            xprt->stat.bind_count,
 719            xprt->stat.connect_count,
 720            xprt->stat.connect_time,
 721            idle_time,
 722            xprt->stat.sends,
 723            xprt->stat.recvs,
 724            xprt->stat.bad_xids,
 725            xprt->stat.req_u,
 726            xprt->stat.bklog_u,
 727
 728            r_xprt->rx_stats.read_chunk_count,
 729            r_xprt->rx_stats.write_chunk_count,
 730            r_xprt->rx_stats.reply_chunk_count,
 731            r_xprt->rx_stats.total_rdma_request,
 732            r_xprt->rx_stats.total_rdma_reply,
 733            r_xprt->rx_stats.pullup_copy_count,
 734            r_xprt->rx_stats.fixup_copy_count,
 735            r_xprt->rx_stats.hardway_register_count,
 736            r_xprt->rx_stats.failed_marshal_count,
 737            r_xprt->rx_stats.bad_reply_count);
 738 }
 739
 740 /*
 741  * Plumbing for rpc transport switch and kernel module
 742  */
 743
 744 static struct rpc_xprt_ops xprt_rdma_procs = {
 745         .reserve_xprt           = xprt_rdma_reserve_xprt,
 746         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 747         .release_request        = xprt_release_rqst_cong,       /* ditto */
 748         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 749         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 750         .set_port               = xprt_rdma_set_port,
 751         .connect                = xprt_rdma_connect,
 752         .buf_alloc              = xprt_rdma_allocate,
 753         .buf_free               = xprt_rdma_free,
 754         .send_request           = xprt_rdma_send_request,
 755         .close                  = xprt_rdma_close,
 756         .destroy                = xprt_rdma_destroy,
 757         .print_stats            = xprt_rdma_print_stats
 758 };
 759
 760 static struct xprt_class xprt_rdma = {
 761         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 762         .name                   = "rdma",
 763         .owner                  = THIS_MODULE,
 764         .ident                  = XPRT_TRANSPORT_RDMA,
 765         .setup                  = xprt_setup_rdma,
 766 };
 767
 768 static void __exit xprt_rdma_cleanup(void)
 769 {
 770         int rc;
 771
 772         dprintk(KERN_INFO "RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 773 #ifdef RPC_DEBUG
 774         if (sunrpc_table_header) {
 775                 unregister_sysctl_table(sunrpc_table_header);
 776                 sunrpc_table_header = NULL;
 777         }
 778 #endif
 779         rc = xprt_unregister_transport(&xprt_rdma);
 780         if (rc)
 781                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 782                         __func__, rc);
 783 }
 784
 785 static int __init xprt_rdma_init(void)
 786 {
 787         int rc;
 788
 789         rc = xprt_register_transport(&xprt_rdma);
 790
 791         if (rc)
 792                 return rc;
 793
 794         dprintk(KERN_INFO "RPCRDMA Module Init, register RPC RDMA transport\n");
 795
 796         dprintk(KERN_INFO "Defaults:\n");
 797         dprintk(KERN_INFO "\tSlots %d\n"
 798                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 799                 xprt_rdma_slot_table_entries,
 800                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 801         dprintk(KERN_INFO "\tPadding %d\n\tMemreg %d\n",
 802                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 803
 804 #ifdef RPC_DEBUG
 805         if (!sunrpc_table_header)
 806                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 807 #endif
 808         return 0;
 809 }
 810
 811 module_init(xprt_rdma_init);
 812 module_exit(xprt_rdma_cleanup);