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 static 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 #define RPCRDMA_BIND_TO         (60U * HZ)
 147 #define RPCRDMA_INIT_REEST_TO   (5U * HZ)
 148 #define RPCRDMA_MAX_REEST_TO    (30U * HZ)
 149 #define RPCRDMA_IDLE_DISC_TO    (5U * 60 * HZ)
 150
 151 static struct rpc_xprt_ops xprt_rdma_procs;     /* forward reference */
 152
 153 static void
 154 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 155 {
 156         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 157         char buf[20];
 158
 159         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 160         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 161
 162         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 163 }
 164
 165 static void
 166 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 167 {
 168         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 169         char buf[40];
 170
 171         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 172         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 173
 174         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 175 }
 176
 177 static void
 178 xprt_rdma_format_addresses(struct rpc_xprt *xprt)
 179 {
 180         struct sockaddr *sap = (struct sockaddr *)
 181                                         &rpcx_to_rdmad(xprt).addr;
 182         char buf[128];
 183
 184         switch (sap->sa_family) {
 185         case AF_INET:
 186                 xprt_rdma_format_addresses4(xprt, sap);
 187                 break;
 188         case AF_INET6:
 189                 xprt_rdma_format_addresses6(xprt, sap);
 190                 break;
 191         default:
 192                 pr_err("rpcrdma: Unrecognized address family\n");
 193                 return;
 194         }
 195
 196         (void)rpc_ntop(sap, buf, sizeof(buf));
 197         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 198
 199         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 200         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 201
 202         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 203         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 204
 205         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 206 }
 207
 208 static void
 209 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 210 {
 211         unsigned int i;
 212
 213         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 214                 switch (i) {
 215                 case RPC_DISPLAY_PROTO:
 216                 case RPC_DISPLAY_NETID:
 217                         continue;
 218                 default:
 219                         kfree(xprt->address_strings[i]);
 220                 }
 221 }
 222
 223 static void
 224 xprt_rdma_connect_worker(struct work_struct *work)
 225 {
 226         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 227                                                    rx_connect_worker.work);
 228         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 229         int rc = 0;
 230
 231         xprt_clear_connected(xprt);
 232
 233         dprintk("RPC:       %s: %sconnect\n", __func__,
 234                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 235         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 236         if (rc)
 237                 xprt_wake_pending_tasks(xprt, rc);
 238
 239         dprintk("RPC:       %s: exit\n", __func__);
 240         xprt_clear_connecting(xprt);
 241 }
 242
 243 /*
 244  * xprt_rdma_destroy
 245  *
 246  * Destroy the xprt.
 247  * Free all memory associated with the object, including its own.
 248  * NOTE: none of the *destroy methods free memory for their top-level
 249  * objects, even though they may have allocated it (they do free
 250  * private memory). It's up to the caller to handle it. In this
 251  * case (RDMA transport), all structure memory is inlined with the
 252  * struct rpcrdma_xprt.
 253  */
 254 static void
 255 xprt_rdma_destroy(struct rpc_xprt *xprt)
 256 {
 257         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 258
 259         dprintk("RPC:       %s: called\n", __func__);
 260
 261         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 262
 263         xprt_clear_connected(xprt);
 264
 265         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 266         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 267         rpcrdma_ia_close(&r_xprt->rx_ia);
 268
 269         xprt_rdma_free_addresses(xprt);
 270
 271         xprt_free(xprt);
 272
 273         dprintk("RPC:       %s: returning\n", __func__);
 274
 275         module_put(THIS_MODULE);
 276 }
 277
 278 static const struct rpc_timeout xprt_rdma_default_timeout = {
 279         .to_initval = 60 * HZ,
 280         .to_maxval = 60 * HZ,
 281 };
 282
 283 /**
 284  * xprt_setup_rdma - Set up transport to use RDMA
 285  *
 286  * @args: rpc transport arguments
 287  */
 288 static struct rpc_xprt *
 289 xprt_setup_rdma(struct xprt_create *args)
 290 {
 291         struct rpcrdma_create_data_internal cdata;
 292         struct rpc_xprt *xprt;
 293         struct rpcrdma_xprt *new_xprt;
 294         struct rpcrdma_ep *new_ep;
 295         struct sockaddr_in *sin;
 296         int rc;
 297
 298         if (args->addrlen > sizeof(xprt->addr)) {
 299                 dprintk("RPC:       %s: address too large\n", __func__);
 300                 return ERR_PTR(-EBADF);
 301         }
 302
 303         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 304                         xprt_rdma_slot_table_entries,
 305                         xprt_rdma_slot_table_entries);
 306         if (xprt == NULL) {
 307                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 308                         __func__);
 309                 return ERR_PTR(-ENOMEM);
 310         }
 311
 312         /* 60 second timeout, no retries */
 313         xprt->timeout = &xprt_rdma_default_timeout;
 314         xprt->bind_timeout = RPCRDMA_BIND_TO;
 315         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 316         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 317
 318         xprt->resvport = 0;             /* privileged port not needed */
 319         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 320         xprt->ops = &xprt_rdma_procs;
 321
 322         /*
 323          * Set up RDMA-specific connect data.
 324          */
 325
 326         /* Put server RDMA address in local cdata */
 327         memcpy(&cdata.addr, args->dstaddr, args->addrlen);
 328
 329         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 330          * address, for any side protocols which peek at it */
 331         xprt->prot = IPPROTO_TCP;
 332         xprt->addrlen = args->addrlen;
 333         memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
 334
 335         sin = (struct sockaddr_in *)&cdata.addr;
 336         if (ntohs(sin->sin_port) != 0)
 337                 xprt_set_bound(xprt);
 338
 339         dprintk("RPC:       %s: %pI4:%u\n",
 340                 __func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
 341
 342         /* Set max requests */
 343         cdata.max_requests = xprt->max_reqs;
 344
 345         /* Set some length limits */
 346         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 347         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 348
 349         cdata.inline_wsize = xprt_rdma_max_inline_write;
 350         if (cdata.inline_wsize > cdata.wsize)
 351                 cdata.inline_wsize = cdata.wsize;
 352
 353         cdata.inline_rsize = xprt_rdma_max_inline_read;
 354         if (cdata.inline_rsize > cdata.rsize)
 355                 cdata.inline_rsize = cdata.rsize;
 356
 357         cdata.padding = xprt_rdma_inline_write_padding;
 358
 359         /*
 360          * Create new transport instance, which includes initialized
 361          *  o ia
 362          *  o endpoint
 363          *  o buffers
 364          */
 365
 366         new_xprt = rpcx_to_rdmax(xprt);
 367
 368         rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
 369                                 xprt_rdma_memreg_strategy);
 370         if (rc)
 371                 goto out1;
 372
 373         /*
 374          * initialize and create ep
 375          */
 376         new_xprt->rx_data = cdata;
 377         new_ep = &new_xprt->rx_ep;
 378         new_ep->rep_remote_addr = cdata.addr;
 379
 380         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 381                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 382         if (rc)
 383                 goto out2;
 384
 385         /*
 386          * Allocate pre-registered send and receive buffers for headers and
 387          * any inline data. Also specify any padding which will be provided
 388          * from a preregistered zero buffer.
 389          */
 390         rc = rpcrdma_buffer_create(new_xprt);
 391         if (rc)
 392                 goto out3;
 393
 394         /*
 395          * Register a callback for connection events. This is necessary because
 396          * connection loss notification is async. We also catch connection loss
 397          * when reaping receives.
 398          */
 399         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 400                           xprt_rdma_connect_worker);
 401
 402         xprt_rdma_format_addresses(xprt);
 403         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 404         if (xprt->max_payload == 0)
 405                 goto out4;
 406         xprt->max_payload <<= PAGE_SHIFT;
 407         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 408                 __func__, xprt->max_payload);
 409
 410         if (!try_module_get(THIS_MODULE))
 411                 goto out4;
 412
 413         return xprt;
 414
 415 out4:
 416         xprt_rdma_free_addresses(xprt);
 417         rc = -EINVAL;
 418 out3:
 419         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 420 out2:
 421         rpcrdma_ia_close(&new_xprt->rx_ia);
 422 out1:
 423         xprt_free(xprt);
 424         return ERR_PTR(rc);
 425 }
 426
 427 /*
 428  * Close a connection, during shutdown or timeout/reconnect
 429  */
 430 static void
 431 xprt_rdma_close(struct rpc_xprt *xprt)
 432 {
 433         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 434
 435         dprintk("RPC:       %s: closing\n", __func__);
 436         if (r_xprt->rx_ep.rep_connected > 0)
 437                 xprt->reestablish_timeout = 0;
 438         xprt_disconnect_done(xprt);
 439         rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 440 }
 441
 442 static void
 443 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 444 {
 445         struct sockaddr_in *sap;
 446
 447         sap = (struct sockaddr_in *)&xprt->addr;
 448         sap->sin_port = htons(port);
 449         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 450         sap->sin_port = htons(port);
 451         dprintk("RPC:       %s: %u\n", __func__, port);
 452 }
 453
 454 static void
 455 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 456 {
 457         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 458
 459         if (r_xprt->rx_ep.rep_connected != 0) {
 460                 /* Reconnect */
 461                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 462                                       xprt->reestablish_timeout);
 463                 xprt->reestablish_timeout <<= 1;
 464                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 465                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 466                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 467                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 468         } else {
 469                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 470                 if (!RPC_IS_ASYNC(task))
 471                         flush_delayed_work(&r_xprt->rx_connect_worker);
 472         }
 473 }
 474
 475 /*
 476  * The RDMA allocate/free functions need the task structure as a place
 477  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 478  * sequence.
 479  *
 480  * The RPC layer allocates both send and receive buffers in the same call
 481  * (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
 482  * We may register rq_rcv_buf when using reply chunks.
 483  */
 484 static void *
 485 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 486 {
 487         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
 488         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 489         struct rpcrdma_regbuf *rb;
 490         struct rpcrdma_req *req;
 491         size_t min_size;
 492         gfp_t flags;
 493
 494         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 495         if (req == NULL)
 496                 return NULL;
 497
 498         flags = GFP_NOIO | __GFP_NOWARN;
 499         if (RPC_IS_SWAPPER(task))
 500                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 501
 502         if (req->rl_rdmabuf == NULL)
 503                 goto out_rdmabuf;
 504         if (req->rl_sendbuf == NULL)
 505                 goto out_sendbuf;
 506         if (size > req->rl_sendbuf->rg_size)
 507                 goto out_sendbuf;
 508
 509 out:
 510         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 511         req->rl_connect_cookie = 0;     /* our reserved value */
 512         return req->rl_sendbuf->rg_base;
 513
 514 out_rdmabuf:
 515         min_size = RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 516         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, min_size, flags);
 517         if (IS_ERR(rb))
 518                 goto out_fail;
 519         req->rl_rdmabuf = rb;
 520
 521 out_sendbuf:
 522         /* XDR encoding and RPC/RDMA marshaling of this request has not
 523          * yet occurred. Thus a lower bound is needed to prevent buffer
 524          * overrun during marshaling.
 525          *
 526          * RPC/RDMA marshaling may choose to send payload bearing ops
 527          * inline, if the result is smaller than the inline threshold.
 528          * The value of the "size" argument accounts for header
 529          * requirements but not for the payload in these cases.
 530          *
 531          * Likewise, allocate enough space to receive a reply up to the
 532          * size of the inline threshold.
 533          *
 534          * It's unlikely that both the send header and the received
 535          * reply will be large, but slush is provided here to allow
 536          * flexibility when marshaling.
 537          */
 538         min_size = RPCRDMA_INLINE_READ_THRESHOLD(task->tk_rqstp);
 539         min_size += RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 540         if (size < min_size)
 541                 size = min_size;
 542
 543         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags);
 544         if (IS_ERR(rb))
 545                 goto out_fail;
 546         rb->rg_owner = req;
 547
 548         r_xprt->rx_stats.hardway_register_count += size;
 549         rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
 550         req->rl_sendbuf = rb;
 551         goto out;
 552
 553 out_fail:
 554         rpcrdma_buffer_put(req);
 555         r_xprt->rx_stats.failed_marshal_count++;
 556         return NULL;
 557 }
 558
 559 /*
 560  * This function returns all RDMA resources to the pool.
 561  */
 562 static void
 563 xprt_rdma_free(void *buffer)
 564 {
 565         struct rpcrdma_req *req;
 566         struct rpcrdma_xprt *r_xprt;
 567         struct rpcrdma_regbuf *rb;
 568         int i;
 569
 570         if (buffer == NULL)
 571                 return;
 572
 573         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
 574         req = rb->rg_owner;
 575         r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 576
 577         dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 578
 579         for (i = 0; req->rl_nchunks;) {
 580                 --req->rl_nchunks;
 581                 i += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt,
 582                                                     &req->rl_segments[i]);
 583         }
 584
 585         rpcrdma_buffer_put(req);
 586 }
 587
 588 /*
 589  * send_request invokes the meat of RPC RDMA. It must do the following:
 590  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 591  *      putting a header in front of data, and creating IOVs for RDMA
 592  *      from those in the request.
 593  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 594  *  3.  Post a recv message to set up asynch completion, then send
 595  *      the request (rpcrdma_ep_post).
 596  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 597  */
 598
 599 static int
 600 xprt_rdma_send_request(struct rpc_task *task)
 601 {
 602         struct rpc_rqst *rqst = task->tk_rqstp;
 603         struct rpc_xprt *xprt = rqst->rq_xprt;
 604         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 605         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 606         int rc = 0;
 607
 608         rc = rpcrdma_marshal_req(rqst);
 609         if (rc < 0)
 610                 goto failed_marshal;
 611
 612         if (req->rl_reply == NULL)              /* e.g. reconnection */
 613                 rpcrdma_recv_buffer_get(req);
 614
 615         if (req->rl_reply) {
 616                 req->rl_reply->rr_func = rpcrdma_reply_handler;
 617                 /* this need only be done once, but... */
 618                 req->rl_reply->rr_xprt = xprt;
 619         }
 620
 621         /* Must suppress retransmit to maintain credits */
 622         if (req->rl_connect_cookie == xprt->connect_cookie)
 623                 goto drop_connection;
 624         req->rl_connect_cookie = xprt->connect_cookie;
 625
 626         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 627                 goto drop_connection;
 628
 629         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 630         rqst->rq_bytes_sent = 0;
 631         return 0;
 632
 633 failed_marshal:
 634         r_xprt->rx_stats.failed_marshal_count++;
 635         dprintk("RPC:       %s: rpcrdma_marshal_req failed, status %i\n",
 636                 __func__, rc);
 637         if (rc == -EIO)
 638                 return -EIO;
 639 drop_connection:
 640         xprt_disconnect_done(xprt);
 641         return -ENOTCONN;       /* implies disconnect */
 642 }
 643
 644 static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 645 {
 646         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 647         long idle_time = 0;
 648
 649         if (xprt_connected(xprt))
 650                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 651
 652         seq_printf(seq,
 653           "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
 654           "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
 655
 656            0,   /* need a local port? */
 657            xprt->stat.bind_count,
 658            xprt->stat.connect_count,
 659            xprt->stat.connect_time,
 660            idle_time,
 661            xprt->stat.sends,
 662            xprt->stat.recvs,
 663            xprt->stat.bad_xids,
 664            xprt->stat.req_u,
 665            xprt->stat.bklog_u,
 666
 667            r_xprt->rx_stats.read_chunk_count,
 668            r_xprt->rx_stats.write_chunk_count,
 669            r_xprt->rx_stats.reply_chunk_count,
 670            r_xprt->rx_stats.total_rdma_request,
 671            r_xprt->rx_stats.total_rdma_reply,
 672            r_xprt->rx_stats.pullup_copy_count,
 673            r_xprt->rx_stats.fixup_copy_count,
 674            r_xprt->rx_stats.hardway_register_count,
 675            r_xprt->rx_stats.failed_marshal_count,
 676            r_xprt->rx_stats.bad_reply_count);
 677 }
 678
 679 /*
 680  * Plumbing for rpc transport switch and kernel module
 681  */
 682
 683 static struct rpc_xprt_ops xprt_rdma_procs = {
 684         .reserve_xprt           = xprt_reserve_xprt_cong,
 685         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 686         .alloc_slot             = xprt_alloc_slot,
 687         .release_request        = xprt_release_rqst_cong,       /* ditto */
 688         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 689         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 690         .set_port               = xprt_rdma_set_port,
 691         .connect                = xprt_rdma_connect,
 692         .buf_alloc              = xprt_rdma_allocate,
 693         .buf_free               = xprt_rdma_free,
 694         .send_request           = xprt_rdma_send_request,
 695         .close                  = xprt_rdma_close,
 696         .destroy                = xprt_rdma_destroy,
 697         .print_stats            = xprt_rdma_print_stats
 698 };
 699
 700 static struct xprt_class xprt_rdma = {
 701         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 702         .name                   = "rdma",
 703         .owner                  = THIS_MODULE,
 704         .ident                  = XPRT_TRANSPORT_RDMA,
 705         .setup                  = xprt_setup_rdma,
 706 };
 707
 708 void xprt_rdma_cleanup(void)
 709 {
 710         int rc;
 711
 712         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 713 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 714         if (sunrpc_table_header) {
 715                 unregister_sysctl_table(sunrpc_table_header);
 716                 sunrpc_table_header = NULL;
 717         }
 718 #endif
 719         rc = xprt_unregister_transport(&xprt_rdma);
 720         if (rc)
 721                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 722                         __func__, rc);
 723 }
 724
 725 int xprt_rdma_init(void)
 726 {
 727         int rc;
 728
 729         rc = xprt_register_transport(&xprt_rdma);
 730
 731         if (rc)
 732                 return rc;
 733
 734         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 735
 736         dprintk("Defaults:\n");
 737         dprintk("\tSlots %d\n"
 738                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 739                 xprt_rdma_slot_table_entries,
 740                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 741         dprintk("\tPadding %d\n\tMemreg %d\n",
 742                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 743
 744 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 745         if (!sunrpc_table_header)
 746                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 747 #endif
 748         return 0;
 749 }