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/slab.h>
  52 #include <linux/seq_file.h>
  53 #include <linux/sunrpc/addr.h>
  54
  55 #include "xprt_rdma.h"
  56
  57 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  58 # define RPCDBG_FACILITY        RPCDBG_TRANS
  59 #endif
  60
  61 /*
  62  * tunables
  63  */
  64
  65 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  66 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  67 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  68 static unsigned int xprt_rdma_inline_write_padding;
  69 static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
  70                 int xprt_rdma_pad_optimize = 1;
  71
  72 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  73
  74 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  75 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  76 static unsigned int zero;
  77 static unsigned int max_padding = PAGE_SIZE;
  78 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  79 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  80
  81 static struct ctl_table_header *sunrpc_table_header;
  82
  83 static struct ctl_table xr_tunables_table[] = {
  84         {
  85                 .procname       = "rdma_slot_table_entries",
  86                 .data           = &xprt_rdma_slot_table_entries,
  87                 .maxlen         = sizeof(unsigned int),
  88                 .mode           = 0644,
  89                 .proc_handler   = proc_dointvec_minmax,
  90                 .extra1         = &min_slot_table_size,
  91                 .extra2         = &max_slot_table_size
  92         },
  93         {
  94                 .procname       = "rdma_max_inline_read",
  95                 .data           = &xprt_rdma_max_inline_read,
  96                 .maxlen         = sizeof(unsigned int),
  97                 .mode           = 0644,
  98                 .proc_handler   = proc_dointvec,
  99         },
 100         {
 101                 .procname       = "rdma_max_inline_write",
 102                 .data           = &xprt_rdma_max_inline_write,
 103                 .maxlen         = sizeof(unsigned int),
 104                 .mode           = 0644,
 105                 .proc_handler   = proc_dointvec,
 106         },
 107         {
 108                 .procname       = "rdma_inline_write_padding",
 109                 .data           = &xprt_rdma_inline_write_padding,
 110                 .maxlen         = sizeof(unsigned int),
 111                 .mode           = 0644,
 112                 .proc_handler   = proc_dointvec_minmax,
 113                 .extra1         = &zero,
 114                 .extra2         = &max_padding,
 115         },
 116         {
 117                 .procname       = "rdma_memreg_strategy",
 118                 .data           = &xprt_rdma_memreg_strategy,
 119                 .maxlen         = sizeof(unsigned int),
 120                 .mode           = 0644,
 121                 .proc_handler   = proc_dointvec_minmax,
 122                 .extra1         = &min_memreg,
 123                 .extra2         = &max_memreg,
 124         },
 125         {
 126                 .procname       = "rdma_pad_optimize",
 127                 .data           = &xprt_rdma_pad_optimize,
 128                 .maxlen         = sizeof(unsigned int),
 129                 .mode           = 0644,
 130                 .proc_handler   = proc_dointvec,
 131         },
 132         { },
 133 };
 134
 135 static struct ctl_table sunrpc_table[] = {
 136         {
 137                 .procname       = "sunrpc",
 138                 .mode           = 0555,
 139                 .child          = xr_tunables_table
 140         },
 141         { },
 142 };
 143
 144 #endif
 145
 146 static struct rpc_xprt_ops xprt_rdma_procs;     /*forward reference */
 147
 148 static void
 149 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 150 {
 151         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 152         char buf[20];
 153
 154         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 155         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 156
 157         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 158 }
 159
 160 static void
 161 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 162 {
 163         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 164         char buf[40];
 165
 166         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 167         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 168
 169         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 170 }
 171
 172 void
 173 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 174 {
 175         char buf[128];
 176
 177         switch (sap->sa_family) {
 178         case AF_INET:
 179                 xprt_rdma_format_addresses4(xprt, sap);
 180                 break;
 181         case AF_INET6:
 182                 xprt_rdma_format_addresses6(xprt, sap);
 183                 break;
 184         default:
 185                 pr_err("rpcrdma: Unrecognized address family\n");
 186                 return;
 187         }
 188
 189         (void)rpc_ntop(sap, buf, sizeof(buf));
 190         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 191
 192         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 193         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 194
 195         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 196         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 197
 198         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 199 }
 200
 201 void
 202 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 203 {
 204         unsigned int i;
 205
 206         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 207                 switch (i) {
 208                 case RPC_DISPLAY_PROTO:
 209                 case RPC_DISPLAY_NETID:
 210                         continue;
 211                 default:
 212                         kfree(xprt->address_strings[i]);
 213                 }
 214 }
 215
 216 static void
 217 xprt_rdma_connect_worker(struct work_struct *work)
 218 {
 219         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 220                                                    rx_connect_worker.work);
 221         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 222         int rc = 0;
 223
 224         xprt_clear_connected(xprt);
 225
 226         dprintk("RPC:       %s: %sconnect\n", __func__,
 227                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 228         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 229         if (rc)
 230                 xprt_wake_pending_tasks(xprt, rc);
 231
 232         dprintk("RPC:       %s: exit\n", __func__);
 233         xprt_clear_connecting(xprt);
 234 }
 235
 236 static void
 237 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 238 {
 239         struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
 240                                                    rx_xprt);
 241
 242         pr_info("rpcrdma: injecting transport disconnect on xprt=%p\n", xprt);
 243         rdma_disconnect(r_xprt->rx_ia.ri_id);
 244 }
 245
 246 /*
 247  * xprt_rdma_destroy
 248  *
 249  * Destroy the xprt.
 250  * Free all memory associated with the object, including its own.
 251  * NOTE: none of the *destroy methods free memory for their top-level
 252  * objects, even though they may have allocated it (they do free
 253  * private memory). It's up to the caller to handle it. In this
 254  * case (RDMA transport), all structure memory is inlined with the
 255  * struct rpcrdma_xprt.
 256  */
 257 static void
 258 xprt_rdma_destroy(struct rpc_xprt *xprt)
 259 {
 260         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 261
 262         dprintk("RPC:       %s: called\n", __func__);
 263
 264         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 265
 266         xprt_clear_connected(xprt);
 267
 268         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 269         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 270         rpcrdma_ia_close(&r_xprt->rx_ia);
 271
 272         xprt_rdma_free_addresses(xprt);
 273
 274         xprt_free(xprt);
 275
 276         dprintk("RPC:       %s: returning\n", __func__);
 277
 278         module_put(THIS_MODULE);
 279 }
 280
 281 static const struct rpc_timeout xprt_rdma_default_timeout = {
 282         .to_initval = 60 * HZ,
 283         .to_maxval = 60 * HZ,
 284 };
 285
 286 /**
 287  * xprt_setup_rdma - Set up transport to use RDMA
 288  *
 289  * @args: rpc transport arguments
 290  */
 291 static struct rpc_xprt *
 292 xprt_setup_rdma(struct xprt_create *args)
 293 {
 294         struct rpcrdma_create_data_internal cdata;
 295         struct rpc_xprt *xprt;
 296         struct rpcrdma_xprt *new_xprt;
 297         struct rpcrdma_ep *new_ep;
 298         struct sockaddr *sap;
 299         int rc;
 300
 301         if (args->addrlen > sizeof(xprt->addr)) {
 302                 dprintk("RPC:       %s: address too large\n", __func__);
 303                 return ERR_PTR(-EBADF);
 304         }
 305
 306         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 307                         xprt_rdma_slot_table_entries,
 308                         xprt_rdma_slot_table_entries);
 309         if (xprt == NULL) {
 310                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 311                         __func__);
 312                 return ERR_PTR(-ENOMEM);
 313         }
 314
 315         /* 60 second timeout, no retries */
 316         xprt->timeout = &xprt_rdma_default_timeout;
 317         xprt->bind_timeout = RPCRDMA_BIND_TO;
 318         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 319         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 320
 321         xprt->resvport = 0;             /* privileged port not needed */
 322         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 323         xprt->ops = &xprt_rdma_procs;
 324
 325         /*
 326          * Set up RDMA-specific connect data.
 327          */
 328
 329         sap = (struct sockaddr *)&cdata.addr;
 330         memcpy(sap, args->dstaddr, args->addrlen);
 331
 332         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 333          * address, for any side protocols which peek at it */
 334         xprt->prot = IPPROTO_TCP;
 335         xprt->addrlen = args->addrlen;
 336         memcpy(&xprt->addr, sap, xprt->addrlen);
 337
 338         if (rpc_get_port(sap))
 339                 xprt_set_bound(xprt);
 340
 341         cdata.max_requests = xprt->max_reqs;
 342
 343         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 344         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 345
 346         cdata.inline_wsize = xprt_rdma_max_inline_write;
 347         if (cdata.inline_wsize > cdata.wsize)
 348                 cdata.inline_wsize = cdata.wsize;
 349
 350         cdata.inline_rsize = xprt_rdma_max_inline_read;
 351         if (cdata.inline_rsize > cdata.rsize)
 352                 cdata.inline_rsize = cdata.rsize;
 353
 354         cdata.padding = xprt_rdma_inline_write_padding;
 355
 356         /*
 357          * Create new transport instance, which includes initialized
 358          *  o ia
 359          *  o endpoint
 360          *  o buffers
 361          */
 362
 363         new_xprt = rpcx_to_rdmax(xprt);
 364
 365         rc = rpcrdma_ia_open(new_xprt, sap, xprt_rdma_memreg_strategy);
 366         if (rc)
 367                 goto out1;
 368
 369         /*
 370          * initialize and create ep
 371          */
 372         new_xprt->rx_data = cdata;
 373         new_ep = &new_xprt->rx_ep;
 374         new_ep->rep_remote_addr = cdata.addr;
 375
 376         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 377                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 378         if (rc)
 379                 goto out2;
 380
 381         /*
 382          * Allocate pre-registered send and receive buffers for headers and
 383          * any inline data. Also specify any padding which will be provided
 384          * from a preregistered zero buffer.
 385          */
 386         rc = rpcrdma_buffer_create(new_xprt);
 387         if (rc)
 388                 goto out3;
 389
 390         /*
 391          * Register a callback for connection events. This is necessary because
 392          * connection loss notification is async. We also catch connection loss
 393          * when reaping receives.
 394          */
 395         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 396                           xprt_rdma_connect_worker);
 397
 398         xprt_rdma_format_addresses(xprt, sap);
 399         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 400         if (xprt->max_payload == 0)
 401                 goto out4;
 402         xprt->max_payload <<= PAGE_SHIFT;
 403         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 404                 __func__, xprt->max_payload);
 405
 406         if (!try_module_get(THIS_MODULE))
 407                 goto out4;
 408
 409         dprintk("RPC:       %s: %s:%s\n", __func__,
 410                 xprt->address_strings[RPC_DISPLAY_ADDR],
 411                 xprt->address_strings[RPC_DISPLAY_PORT]);
 412         return xprt;
 413
 414 out4:
 415         xprt_rdma_free_addresses(xprt);
 416         rc = -EINVAL;
 417 out3:
 418         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 419 out2:
 420         rpcrdma_ia_close(&new_xprt->rx_ia);
 421 out1:
 422         xprt_free(xprt);
 423         return ERR_PTR(rc);
 424 }
 425
 426 /*
 427  * Close a connection, during shutdown or timeout/reconnect
 428  */
 429 static void
 430 xprt_rdma_close(struct rpc_xprt *xprt)
 431 {
 432         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 433
 434         dprintk("RPC:       %s: closing\n", __func__);
 435         if (r_xprt->rx_ep.rep_connected > 0)
 436                 xprt->reestablish_timeout = 0;
 437         xprt_disconnect_done(xprt);
 438         rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 439 }
 440
 441 static void
 442 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 443 {
 444         struct sockaddr_in *sap;
 445
 446         sap = (struct sockaddr_in *)&xprt->addr;
 447         sap->sin_port = htons(port);
 448         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 449         sap->sin_port = htons(port);
 450         dprintk("RPC:       %s: %u\n", __func__, port);
 451 }
 452
 453 static void
 454 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 455 {
 456         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 457
 458         if (r_xprt->rx_ep.rep_connected != 0) {
 459                 /* Reconnect */
 460                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 461                                       xprt->reestablish_timeout);
 462                 xprt->reestablish_timeout <<= 1;
 463                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 464                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 465                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 466                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 467         } else {
 468                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 469                 if (!RPC_IS_ASYNC(task))
 470                         flush_delayed_work(&r_xprt->rx_connect_worker);
 471         }
 472 }
 473
 474 /*
 475  * The RDMA allocate/free functions need the task structure as a place
 476  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 477  * sequence.
 478  *
 479  * The RPC layer allocates both send and receive buffers in the same call
 480  * (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
 481  * We may register rq_rcv_buf when using reply chunks.
 482  */
 483 static void *
 484 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 485 {
 486         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
 487         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 488         struct rpcrdma_regbuf *rb;
 489         struct rpcrdma_req *req;
 490         size_t min_size;
 491         gfp_t flags;
 492
 493         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 494         if (req == NULL)
 495                 return NULL;
 496
 497         flags = RPCRDMA_DEF_GFP;
 498         if (RPC_IS_SWAPPER(task))
 499                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 500
 501         if (req->rl_rdmabuf == NULL)
 502                 goto out_rdmabuf;
 503         if (req->rl_sendbuf == NULL)
 504                 goto out_sendbuf;
 505         if (size > req->rl_sendbuf->rg_size)
 506                 goto out_sendbuf;
 507
 508 out:
 509         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 510         req->rl_connect_cookie = 0;     /* our reserved value */
 511         return req->rl_sendbuf->rg_base;
 512
 513 out_rdmabuf:
 514         min_size = RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 515         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, min_size, flags);
 516         if (IS_ERR(rb))
 517                 goto out_fail;
 518         req->rl_rdmabuf = rb;
 519
 520 out_sendbuf:
 521         /* XDR encoding and RPC/RDMA marshaling of this request has not
 522          * yet occurred. Thus a lower bound is needed to prevent buffer
 523          * overrun during marshaling.
 524          *
 525          * RPC/RDMA marshaling may choose to send payload bearing ops
 526          * inline, if the result is smaller than the inline threshold.
 527          * The value of the "size" argument accounts for header
 528          * requirements but not for the payload in these cases.
 529          *
 530          * Likewise, allocate enough space to receive a reply up to the
 531          * size of the inline threshold.
 532          *
 533          * It's unlikely that both the send header and the received
 534          * reply will be large, but slush is provided here to allow
 535          * flexibility when marshaling.
 536          */
 537         min_size = RPCRDMA_INLINE_READ_THRESHOLD(task->tk_rqstp);
 538         min_size += RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 539         if (size < min_size)
 540                 size = min_size;
 541
 542         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags);
 543         if (IS_ERR(rb))
 544                 goto out_fail;
 545         rb->rg_owner = req;
 546
 547         r_xprt->rx_stats.hardway_register_count += size;
 548         rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
 549         req->rl_sendbuf = rb;
 550         goto out;
 551
 552 out_fail:
 553         rpcrdma_buffer_put(req);
 554         r_xprt->rx_stats.failed_marshal_count++;
 555         return NULL;
 556 }
 557
 558 /*
 559  * This function returns all RDMA resources to the pool.
 560  */
 561 static void
 562 xprt_rdma_free(void *buffer)
 563 {
 564         struct rpcrdma_req *req;
 565         struct rpcrdma_xprt *r_xprt;
 566         struct rpcrdma_regbuf *rb;
 567         int i;
 568
 569         if (buffer == NULL)
 570                 return;
 571
 572         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
 573         req = rb->rg_owner;
 574         if (req->rl_backchannel)
 575                 return;
 576
 577         r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 578
 579         dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 580
 581         for (i = 0; req->rl_nchunks;) {
 582                 --req->rl_nchunks;
 583                 i += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt,
 584                                                     &req->rl_segments[i]);
 585         }
 586
 587         rpcrdma_buffer_put(req);
 588 }
 589
 590 /*
 591  * send_request invokes the meat of RPC RDMA. It must do the following:
 592  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 593  *      putting a header in front of data, and creating IOVs for RDMA
 594  *      from those in the request.
 595  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 596  *  3.  Post a recv message to set up asynch completion, then send
 597  *      the request (rpcrdma_ep_post).
 598  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 599  */
 600
 601 static int
 602 xprt_rdma_send_request(struct rpc_task *task)
 603 {
 604         struct rpc_rqst *rqst = task->tk_rqstp;
 605         struct rpc_xprt *xprt = rqst->rq_xprt;
 606         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 607         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 608         int rc = 0;
 609
 610         rc = rpcrdma_marshal_req(rqst);
 611         if (rc < 0)
 612                 goto failed_marshal;
 613
 614         if (req->rl_reply == NULL)              /* e.g. reconnection */
 615                 rpcrdma_recv_buffer_get(req);
 616
 617         /* Must suppress retransmit to maintain credits */
 618         if (req->rl_connect_cookie == xprt->connect_cookie)
 619                 goto drop_connection;
 620         req->rl_connect_cookie = xprt->connect_cookie;
 621
 622         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 623                 goto drop_connection;
 624
 625         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 626         rqst->rq_bytes_sent = 0;
 627         return 0;
 628
 629 failed_marshal:
 630         r_xprt->rx_stats.failed_marshal_count++;
 631         dprintk("RPC:       %s: rpcrdma_marshal_req failed, status %i\n",
 632                 __func__, rc);
 633         if (rc == -EIO)
 634                 return -EIO;
 635 drop_connection:
 636         xprt_disconnect_done(xprt);
 637         return -ENOTCONN;       /* implies disconnect */
 638 }
 639
 640 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 641 {
 642         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 643         long idle_time = 0;
 644
 645         if (xprt_connected(xprt))
 646                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 647
 648         seq_puts(seq, "\txprt:\trdma ");
 649         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 650                    0,   /* need a local port? */
 651                    xprt->stat.bind_count,
 652                    xprt->stat.connect_count,
 653                    xprt->stat.connect_time,
 654                    idle_time,
 655                    xprt->stat.sends,
 656                    xprt->stat.recvs,
 657                    xprt->stat.bad_xids,
 658                    xprt->stat.req_u,
 659                    xprt->stat.bklog_u);
 660         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu\n",
 661                    r_xprt->rx_stats.read_chunk_count,
 662                    r_xprt->rx_stats.write_chunk_count,
 663                    r_xprt->rx_stats.reply_chunk_count,
 664                    r_xprt->rx_stats.total_rdma_request,
 665                    r_xprt->rx_stats.total_rdma_reply,
 666                    r_xprt->rx_stats.pullup_copy_count,
 667                    r_xprt->rx_stats.fixup_copy_count,
 668                    r_xprt->rx_stats.hardway_register_count,
 669                    r_xprt->rx_stats.failed_marshal_count,
 670                    r_xprt->rx_stats.bad_reply_count,
 671                    r_xprt->rx_stats.nomsg_call_count);
 672 }
 673
 674 static int
 675 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 676 {
 677         return 0;
 678 }
 679
 680 static void
 681 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 682 {
 683 }
 684
 685 /*
 686  * Plumbing for rpc transport switch and kernel module
 687  */
 688
 689 static struct rpc_xprt_ops xprt_rdma_procs = {
 690         .reserve_xprt           = xprt_reserve_xprt_cong,
 691         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 692         .alloc_slot             = xprt_alloc_slot,
 693         .release_request        = xprt_release_rqst_cong,       /* ditto */
 694         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 695         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 696         .set_port               = xprt_rdma_set_port,
 697         .connect                = xprt_rdma_connect,
 698         .buf_alloc              = xprt_rdma_allocate,
 699         .buf_free               = xprt_rdma_free,
 700         .send_request           = xprt_rdma_send_request,
 701         .close                  = xprt_rdma_close,
 702         .destroy                = xprt_rdma_destroy,
 703         .print_stats            = xprt_rdma_print_stats,
 704         .enable_swap            = xprt_rdma_enable_swap,
 705         .disable_swap           = xprt_rdma_disable_swap,
 706         .inject_disconnect      = xprt_rdma_inject_disconnect,
 707 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 708         .bc_setup               = xprt_rdma_bc_setup,
 709         .bc_up                  = xprt_rdma_bc_up,
 710         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 711         .bc_destroy             = xprt_rdma_bc_destroy,
 712 #endif
 713 };
 714
 715 static struct xprt_class xprt_rdma = {
 716         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 717         .name                   = "rdma",
 718         .owner                  = THIS_MODULE,
 719         .ident                  = XPRT_TRANSPORT_RDMA,
 720         .setup                  = xprt_setup_rdma,
 721 };
 722
 723 void xprt_rdma_cleanup(void)
 724 {
 725         int rc;
 726
 727         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 728 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 729         if (sunrpc_table_header) {
 730                 unregister_sysctl_table(sunrpc_table_header);
 731                 sunrpc_table_header = NULL;
 732         }
 733 #endif
 734         rc = xprt_unregister_transport(&xprt_rdma);
 735         if (rc)
 736                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 737                         __func__, rc);
 738
 739         rpcrdma_destroy_wq();
 740         frwr_destroy_recovery_wq();
 741
 742         rc = xprt_unregister_transport(&xprt_rdma_bc);
 743         if (rc)
 744                 dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
 745                         __func__, rc);
 746 }
 747
 748 int xprt_rdma_init(void)
 749 {
 750         int rc;
 751
 752         rc = frwr_alloc_recovery_wq();
 753         if (rc)
 754                 return rc;
 755
 756         rc = rpcrdma_alloc_wq();
 757         if (rc) {
 758                 frwr_destroy_recovery_wq();
 759                 return rc;
 760         }
 761
 762         rc = xprt_register_transport(&xprt_rdma);
 763         if (rc) {
 764                 rpcrdma_destroy_wq();
 765                 frwr_destroy_recovery_wq();
 766                 return rc;
 767         }
 768
 769         rc = xprt_register_transport(&xprt_rdma_bc);
 770         if (rc) {
 771                 xprt_unregister_transport(&xprt_rdma);
 772                 rpcrdma_destroy_wq();
 773                 frwr_destroy_recovery_wq();
 774                 return rc;
 775         }
 776
 777         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 778
 779         dprintk("Defaults:\n");
 780         dprintk("\tSlots %d\n"
 781                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 782                 xprt_rdma_slot_table_entries,
 783                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 784         dprintk("\tPadding %d\n\tMemreg %d\n",
 785                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 786
 787 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 788         if (!sunrpc_table_header)
 789                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 790 #endif
 791         return 0;
 792 }