net/sunrpc/xprtrdma/transport.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright (c) 2014-2017 Oracle.  All rights reserved.
   4  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the BSD-type
  10  * license below:
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  *
  16  *      Redistributions of source code must retain the above copyright
  17  *      notice, this list of conditions and the following disclaimer.
  18  *
  19  *      Redistributions in binary form must reproduce the above
  20  *      copyright notice, this list of conditions and the following
  21  *      disclaimer in the documentation and/or other materials provided
  22  *      with the distribution.
  23  *
  24  *      Neither the name of the Network Appliance, Inc. nor the names of
  25  *      its contributors may be used to endorse or promote products
  26  *      derived from this software without specific prior written
  27  *      permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  33  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 /*
  43  * transport.c
  44  *
  45  * This file contains the top-level implementation of an RPC RDMA
  46  * transport.
  47  *
  48  * Naming convention: functions beginning with xprt_ are part of the
  49  * transport switch. All others are RPC RDMA internal.
  50  */
  51
  52 #include <linux/module.h>
  53 #include <linux/slab.h>
  54 #include <linux/seq_file.h>
  55 #include <linux/smp.h>
  56
  57 #include <linux/sunrpc/addr.h>
  58 #include <linux/sunrpc/svc_rdma.h>
  59
  60 #include "xprt_rdma.h"
  61 #include <trace/events/rpcrdma.h>
  62
  63 /*
  64  * tunables
  65  */
  66
  67 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  68 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  69 unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  70 unsigned int xprt_rdma_memreg_strategy          = RPCRDMA_FRWR;
  71 int xprt_rdma_pad_optimize;
  72 static struct xprt_class xprt_rdma;
  73
  74 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  75
  76 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  77 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  78 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  79 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  80 static unsigned int max_padding = PAGE_SIZE;
  81 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  82 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  83 static unsigned int dummy;
  84
  85 static struct ctl_table_header *sunrpc_table_header;
  86
  87 static struct ctl_table xr_tunables_table[] = {
  88         {
  89                 .procname       = "rdma_slot_table_entries",
  90                 .data           = &xprt_rdma_slot_table_entries,
  91                 .maxlen         = sizeof(unsigned int),
  92                 .mode           = 0644,
  93                 .proc_handler   = proc_dointvec_minmax,
  94                 .extra1         = &min_slot_table_size,
  95                 .extra2         = &max_slot_table_size
  96         },
  97         {
  98                 .procname       = "rdma_max_inline_read",
  99                 .data           = &xprt_rdma_max_inline_read,
 100                 .maxlen         = sizeof(unsigned int),
 101                 .mode           = 0644,
 102                 .proc_handler   = proc_dointvec_minmax,
 103                 .extra1         = &min_inline_size,
 104                 .extra2         = &max_inline_size,
 105         },
 106         {
 107                 .procname       = "rdma_max_inline_write",
 108                 .data           = &xprt_rdma_max_inline_write,
 109                 .maxlen         = sizeof(unsigned int),
 110                 .mode           = 0644,
 111                 .proc_handler   = proc_dointvec_minmax,
 112                 .extra1         = &min_inline_size,
 113                 .extra2         = &max_inline_size,
 114         },
 115         {
 116                 .procname       = "rdma_inline_write_padding",
 117                 .data           = &dummy,
 118                 .maxlen         = sizeof(unsigned int),
 119                 .mode           = 0644,
 120                 .proc_handler   = proc_dointvec_minmax,
 121                 .extra1         = SYSCTL_ZERO,
 122                 .extra2         = &max_padding,
 123         },
 124         {
 125                 .procname       = "rdma_memreg_strategy",
 126                 .data           = &xprt_rdma_memreg_strategy,
 127                 .maxlen         = sizeof(unsigned int),
 128                 .mode           = 0644,
 129                 .proc_handler   = proc_dointvec_minmax,
 130                 .extra1         = &min_memreg,
 131                 .extra2         = &max_memreg,
 132         },
 133         {
 134                 .procname       = "rdma_pad_optimize",
 135                 .data           = &xprt_rdma_pad_optimize,
 136                 .maxlen         = sizeof(unsigned int),
 137                 .mode           = 0644,
 138                 .proc_handler   = proc_dointvec,
 139         },
 140         { },
 141 };
 142
 143 static struct ctl_table sunrpc_table[] = {
 144         {
 145                 .procname       = "sunrpc",
 146                 .mode           = 0555,
 147                 .child          = xr_tunables_table
 148         },
 149         { },
 150 };
 151
 152 #endif
 153
 154 static const struct rpc_xprt_ops xprt_rdma_procs;
 155
 156 static void
 157 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 158 {
 159         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 160         char buf[20];
 161
 162         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 163         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 164
 165         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 166 }
 167
 168 static void
 169 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 170 {
 171         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 172         char buf[40];
 173
 174         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 175         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 176
 177         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 178 }
 179
 180 void
 181 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 182 {
 183         char buf[128];
 184
 185         switch (sap->sa_family) {
 186         case AF_INET:
 187                 xprt_rdma_format_addresses4(xprt, sap);
 188                 break;
 189         case AF_INET6:
 190                 xprt_rdma_format_addresses6(xprt, sap);
 191                 break;
 192         default:
 193                 pr_err("rpcrdma: Unrecognized address family\n");
 194                 return;
 195         }
 196
 197         (void)rpc_ntop(sap, buf, sizeof(buf));
 198         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 199
 200         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 201         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 202
 203         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 204         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 205
 206         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 207 }
 208
 209 void
 210 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 211 {
 212         unsigned int i;
 213
 214         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 215                 switch (i) {
 216                 case RPC_DISPLAY_PROTO:
 217                 case RPC_DISPLAY_NETID:
 218                         continue;
 219                 default:
 220                         kfree(xprt->address_strings[i]);
 221                 }
 222 }
 223
 224 /**
 225  * xprt_rdma_connect_worker - establish connection in the background
 226  * @work: worker thread context
 227  *
 228  * Requester holds the xprt's send lock to prevent activity on this
 229  * transport while a fresh connection is being established. RPC tasks
 230  * sleep on the xprt's pending queue waiting for connect to complete.
 231  */
 232 static void
 233 xprt_rdma_connect_worker(struct work_struct *work)
 234 {
 235         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 236                                                    rx_connect_worker.work);
 237         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 238         int rc;
 239
 240         rc = rpcrdma_xprt_connect(r_xprt);
 241         xprt_clear_connecting(xprt);
 242         if (!rc) {
 243                 xprt->connect_cookie++;
 244                 xprt->stat.connect_count++;
 245                 xprt->stat.connect_time += (long)jiffies -
 246                                            xprt->stat.connect_start;
 247                 xprt_set_connected(xprt);
 248                 rc = -EAGAIN;
 249         } else
 250                 rpcrdma_xprt_disconnect(r_xprt);
 251         xprt_unlock_connect(xprt, r_xprt);
 252         xprt_wake_pending_tasks(xprt, rc);
 253 }
 254
 255 /**
 256  * xprt_rdma_inject_disconnect - inject a connection fault
 257  * @xprt: transport context
 258  *
 259  * If @xprt is connected, disconnect it to simulate spurious
 260  * connection loss. Caller must hold @xprt's send lock to
 261  * ensure that data structures and hardware resources are
 262  * stable during the rdma_disconnect() call.
 263  */
 264 static void
 265 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 266 {
 267         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 268
 269         trace_xprtrdma_op_inject_dsc(r_xprt);
 270         rdma_disconnect(r_xprt->rx_ep->re_id);
 271 }
 272
 273 /**
 274  * xprt_rdma_destroy - Full tear down of transport
 275  * @xprt: doomed transport context
 276  *
 277  * Caller guarantees there will be no more calls to us with
 278  * this @xprt.
 279  */
 280 static void
 281 xprt_rdma_destroy(struct rpc_xprt *xprt)
 282 {
 283         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 284
 285         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 286
 287         rpcrdma_xprt_disconnect(r_xprt);
 288         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 289
 290         xprt_rdma_free_addresses(xprt);
 291         xprt_free(xprt);
 292
 293         module_put(THIS_MODULE);
 294 }
 295
 296 /* 60 second timeout, no retries */
 297 static const struct rpc_timeout xprt_rdma_default_timeout = {
 298         .to_initval = 60 * HZ,
 299         .to_maxval = 60 * HZ,
 300 };
 301
 302 /**
 303  * xprt_setup_rdma - Set up transport to use RDMA
 304  *
 305  * @args: rpc transport arguments
 306  */
 307 static struct rpc_xprt *
 308 xprt_setup_rdma(struct xprt_create *args)
 309 {
 310         struct rpc_xprt *xprt;
 311         struct rpcrdma_xprt *new_xprt;
 312         struct sockaddr *sap;
 313         int rc;
 314
 315         if (args->addrlen > sizeof(xprt->addr))
 316                 return ERR_PTR(-EBADF);
 317
 318         if (!try_module_get(THIS_MODULE))
 319                 return ERR_PTR(-EIO);
 320
 321         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0,
 322                           xprt_rdma_slot_table_entries);
 323         if (!xprt) {
 324                 module_put(THIS_MODULE);
 325                 return ERR_PTR(-ENOMEM);
 326         }
 327
 328         xprt->timeout = &xprt_rdma_default_timeout;
 329         xprt->connect_timeout = xprt->timeout->to_initval;
 330         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
 331         xprt->bind_timeout = RPCRDMA_BIND_TO;
 332         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 333         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 334
 335         xprt->resvport = 0;             /* privileged port not needed */
 336         xprt->ops = &xprt_rdma_procs;
 337
 338         /*
 339          * Set up RDMA-specific connect data.
 340          */
 341         sap = args->dstaddr;
 342
 343         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 344          * address, for any side protocols which peek at it */
 345         xprt->prot = IPPROTO_TCP;
 346         xprt->xprt_class = &xprt_rdma;
 347         xprt->addrlen = args->addrlen;
 348         memcpy(&xprt->addr, sap, xprt->addrlen);
 349
 350         if (rpc_get_port(sap))
 351                 xprt_set_bound(xprt);
 352         xprt_rdma_format_addresses(xprt, sap);
 353
 354         new_xprt = rpcx_to_rdmax(xprt);
 355         rc = rpcrdma_buffer_create(new_xprt);
 356         if (rc) {
 357                 xprt_rdma_free_addresses(xprt);
 358                 xprt_free(xprt);
 359                 module_put(THIS_MODULE);
 360                 return ERR_PTR(rc);
 361         }
 362
 363         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 364                           xprt_rdma_connect_worker);
 365
 366         xprt->max_payload = RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT;
 367
 368         return xprt;
 369 }
 370
 371 /**
 372  * xprt_rdma_close - close a transport connection
 373  * @xprt: transport context
 374  *
 375  * Called during autoclose or device removal.
 376  *
 377  * Caller holds @xprt's send lock to prevent activity on this
 378  * transport while the connection is torn down.
 379  */
 380 void xprt_rdma_close(struct rpc_xprt *xprt)
 381 {
 382         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 383
 384         rpcrdma_xprt_disconnect(r_xprt);
 385
 386         xprt->reestablish_timeout = 0;
 387         ++xprt->connect_cookie;
 388         xprt_disconnect_done(xprt);
 389 }
 390
 391 /**
 392  * xprt_rdma_set_port - update server port with rpcbind result
 393  * @xprt: controlling RPC transport
 394  * @port: new port value
 395  *
 396  * Transport connect status is unchanged.
 397  */
 398 static void
 399 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 400 {
 401         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 402         char buf[8];
 403
 404         rpc_set_port(sap, port);
 405
 406         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 407         snprintf(buf, sizeof(buf), "%u", port);
 408         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 409
 410         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 411         snprintf(buf, sizeof(buf), "%4hx", port);
 412         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 413 }
 414
 415 /**
 416  * xprt_rdma_timer - invoked when an RPC times out
 417  * @xprt: controlling RPC transport
 418  * @task: RPC task that timed out
 419  *
 420  * Invoked when the transport is still connected, but an RPC
 421  * retransmit timeout occurs.
 422  *
 423  * Since RDMA connections don't have a keep-alive, forcibly
 424  * disconnect and retry to connect. This drives full
 425  * detection of the network path, and retransmissions of
 426  * all pending RPCs.
 427  */
 428 static void
 429 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 430 {
 431         xprt_force_disconnect(xprt);
 432 }
 433
 434 /**
 435  * xprt_rdma_set_connect_timeout - set timeouts for establishing a connection
 436  * @xprt: controlling transport instance
 437  * @connect_timeout: reconnect timeout after client disconnects
 438  * @reconnect_timeout: reconnect timeout after server disconnects
 439  *
 440  */
 441 static void xprt_rdma_set_connect_timeout(struct rpc_xprt *xprt,
 442                                           unsigned long connect_timeout,
 443                                           unsigned long reconnect_timeout)
 444 {
 445         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 446
 447         trace_xprtrdma_op_set_cto(r_xprt, connect_timeout, reconnect_timeout);
 448
 449         spin_lock(&xprt->transport_lock);
 450
 451         if (connect_timeout < xprt->connect_timeout) {
 452                 struct rpc_timeout to;
 453                 unsigned long initval;
 454
 455                 to = *xprt->timeout;
 456                 initval = connect_timeout;
 457                 if (initval < RPCRDMA_INIT_REEST_TO << 1)
 458                         initval = RPCRDMA_INIT_REEST_TO << 1;
 459                 to.to_initval = initval;
 460                 to.to_maxval = initval;
 461                 r_xprt->rx_timeout = to;
 462                 xprt->timeout = &r_xprt->rx_timeout;
 463                 xprt->connect_timeout = connect_timeout;
 464         }
 465
 466         if (reconnect_timeout < xprt->max_reconnect_timeout)
 467                 xprt->max_reconnect_timeout = reconnect_timeout;
 468
 469         spin_unlock(&xprt->transport_lock);
 470 }
 471
 472 /**
 473  * xprt_rdma_connect - schedule an attempt to reconnect
 474  * @xprt: transport state
 475  * @task: RPC scheduler context (unused)
 476  *
 477  */
 478 static void
 479 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 480 {
 481         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 482         struct rpcrdma_ep *ep = r_xprt->rx_ep;
 483         unsigned long delay;
 484
 485         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, r_xprt));
 486
 487         delay = 0;
 488         if (ep && ep->re_connect_status != 0) {
 489                 delay = xprt_reconnect_delay(xprt);
 490                 xprt_reconnect_backoff(xprt, RPCRDMA_INIT_REEST_TO);
 491         }
 492         trace_xprtrdma_op_connect(r_xprt, delay);
 493         queue_delayed_work(xprtiod_workqueue, &r_xprt->rx_connect_worker,
 494                            delay);
 495 }
 496
 497 /**
 498  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 499  * @xprt: controlling RPC transport
 500  * @task: RPC task requesting a fresh rpc_rqst
 501  *
 502  * tk_status values:
 503  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 504  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 505  */
 506 static void
 507 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 508 {
 509         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 510         struct rpcrdma_req *req;
 511
 512         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 513         if (!req)
 514                 goto out_sleep;
 515         task->tk_rqstp = &req->rl_slot;
 516         task->tk_status = 0;
 517         return;
 518
 519 out_sleep:
 520         task->tk_status = -EAGAIN;
 521         xprt_add_backlog(xprt, task);
 522 }
 523
 524 /**
 525  * xprt_rdma_free_slot - release an rpc_rqst
 526  * @xprt: controlling RPC transport
 527  * @rqst: rpc_rqst to release
 528  *
 529  */
 530 static void
 531 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 532 {
 533         struct rpcrdma_xprt *r_xprt =
 534                 container_of(xprt, struct rpcrdma_xprt, rx_xprt);
 535
 536         rpcrdma_reply_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst));
 537         if (!xprt_wake_up_backlog(xprt, rqst)) {
 538                 memset(rqst, 0, sizeof(*rqst));
 539                 rpcrdma_buffer_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst));
 540         }
 541 }
 542
 543 static bool rpcrdma_check_regbuf(struct rpcrdma_xprt *r_xprt,
 544                                  struct rpcrdma_regbuf *rb, size_t size,
 545                                  gfp_t flags)
 546 {
 547         if (unlikely(rdmab_length(rb) < size)) {
 548                 if (!rpcrdma_regbuf_realloc(rb, size, flags))
 549                         return false;
 550                 r_xprt->rx_stats.hardway_register_count += size;
 551         }
 552         return true;
 553 }
 554
 555 /**
 556  * xprt_rdma_allocate - allocate transport resources for an RPC
 557  * @task: RPC task
 558  *
 559  * Return values:
 560  *        0:    Success; rq_buffer points to RPC buffer to use
 561  *   ENOMEM:    Out of memory, call again later
 562  *      EIO:    A permanent error occurred, do not retry
 563  */
 564 static int
 565 xprt_rdma_allocate(struct rpc_task *task)
 566 {
 567         struct rpc_rqst *rqst = task->tk_rqstp;
 568         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 569         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 570         gfp_t flags;
 571
 572         flags = RPCRDMA_DEF_GFP;
 573         if (RPC_IS_SWAPPER(task))
 574                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 575
 576         if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize,
 577                                   flags))
 578                 goto out_fail;
 579         if (!rpcrdma_check_regbuf(r_xprt, req->rl_recvbuf, rqst->rq_rcvsize,
 580                                   flags))
 581                 goto out_fail;
 582
 583         rqst->rq_buffer = rdmab_data(req->rl_sendbuf);
 584         rqst->rq_rbuffer = rdmab_data(req->rl_recvbuf);
 585         return 0;
 586
 587 out_fail:
 588         return -ENOMEM;
 589 }
 590
 591 /**
 592  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 593  * @task: RPC task
 594  *
 595  * Caller guarantees rqst->rq_buffer is non-NULL.
 596  */
 597 static void
 598 xprt_rdma_free(struct rpc_task *task)
 599 {
 600         struct rpc_rqst *rqst = task->tk_rqstp;
 601         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 602
 603         if (unlikely(!list_empty(&req->rl_registered))) {
 604                 trace_xprtrdma_mrs_zap(task);
 605                 frwr_unmap_sync(rpcx_to_rdmax(rqst->rq_xprt), req);
 606         }
 607
 608         /* XXX: If the RPC is completing because of a signal and
 609          * not because a reply was received, we ought to ensure
 610          * that the Send completion has fired, so that memory
 611          * involved with the Send is not still visible to the NIC.
 612          */
 613 }
 614
 615 /**
 616  * xprt_rdma_send_request - marshal and send an RPC request
 617  * @rqst: RPC message in rq_snd_buf
 618  *
 619  * Caller holds the transport's write lock.
 620  *
 621  * Returns:
 622  *      %0 if the RPC message has been sent
 623  *      %-ENOTCONN if the caller should reconnect and call again
 624  *      %-EAGAIN if the caller should call again
 625  *      %-ENOBUFS if the caller should call again after a delay
 626  *      %-EMSGSIZE if encoding ran out of buffer space. The request
 627  *              was not sent. Do not try to send this message again.
 628  *      %-EIO if an I/O error occurred. The request was not sent.
 629  *              Do not try to send this message again.
 630  */
 631 static int
 632 xprt_rdma_send_request(struct rpc_rqst *rqst)
 633 {
 634         struct rpc_xprt *xprt = rqst->rq_xprt;
 635         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 636         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 637         int rc = 0;
 638
 639 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 640         if (unlikely(!rqst->rq_buffer))
 641                 return xprt_rdma_bc_send_reply(rqst);
 642 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 643
 644         if (!xprt_connected(xprt))
 645                 return -ENOTCONN;
 646
 647         if (!xprt_request_get_cong(xprt, rqst))
 648                 return -EBADSLT;
 649
 650         rc = rpcrdma_marshal_req(r_xprt, rqst);
 651         if (rc < 0)
 652                 goto failed_marshal;
 653
 654         /* Must suppress retransmit to maintain credits */
 655         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 656                 goto drop_connection;
 657         rqst->rq_xtime = ktime_get();
 658
 659         if (frwr_send(r_xprt, req))
 660                 goto drop_connection;
 661
 662         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 663
 664         /* An RPC with no reply will throw off credit accounting,
 665          * so drop the connection to reset the credit grant.
 666          */
 667         if (!rpc_reply_expected(rqst->rq_task))
 668                 goto drop_connection;
 669         return 0;
 670
 671 failed_marshal:
 672         if (rc != -ENOTCONN)
 673                 return rc;
 674 drop_connection:
 675         xprt_rdma_close(xprt);
 676         return -ENOTCONN;
 677 }
 678
 679 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 680 {
 681         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 682         long idle_time = 0;
 683
 684         if (xprt_connected(xprt))
 685                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 686
 687         seq_puts(seq, "\txprt:\trdma ");
 688         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 689                    0,   /* need a local port? */
 690                    xprt->stat.bind_count,
 691                    xprt->stat.connect_count,
 692                    xprt->stat.connect_time / HZ,
 693                    idle_time,
 694                    xprt->stat.sends,
 695                    xprt->stat.recvs,
 696                    xprt->stat.bad_xids,
 697                    xprt->stat.req_u,
 698                    xprt->stat.bklog_u);
 699         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 700                    r_xprt->rx_stats.read_chunk_count,
 701                    r_xprt->rx_stats.write_chunk_count,
 702                    r_xprt->rx_stats.reply_chunk_count,
 703                    r_xprt->rx_stats.total_rdma_request,
 704                    r_xprt->rx_stats.total_rdma_reply,
 705                    r_xprt->rx_stats.pullup_copy_count,
 706                    r_xprt->rx_stats.fixup_copy_count,
 707                    r_xprt->rx_stats.hardway_register_count,
 708                    r_xprt->rx_stats.failed_marshal_count,
 709                    r_xprt->rx_stats.bad_reply_count,
 710                    r_xprt->rx_stats.nomsg_call_count);
 711         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 712                    r_xprt->rx_stats.mrs_recycled,
 713                    r_xprt->rx_stats.mrs_orphaned,
 714                    r_xprt->rx_stats.mrs_allocated,
 715                    r_xprt->rx_stats.local_inv_needed,
 716                    r_xprt->rx_stats.empty_sendctx_q,
 717                    r_xprt->rx_stats.reply_waits_for_send);
 718 }
 719
 720 static int
 721 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 722 {
 723         return 0;
 724 }
 725
 726 static void
 727 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 728 {
 729 }
 730
 731 /*
 732  * Plumbing for rpc transport switch and kernel module
 733  */
 734
 735 static const struct rpc_xprt_ops xprt_rdma_procs = {
 736         .reserve_xprt           = xprt_reserve_xprt_cong,
 737         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 738         .alloc_slot             = xprt_rdma_alloc_slot,
 739         .free_slot              = xprt_rdma_free_slot,
 740         .release_request        = xprt_release_rqst_cong,       /* ditto */
 741         .wait_for_reply_request = xprt_wait_for_reply_request_def, /* ditto */
 742         .timer                  = xprt_rdma_timer,
 743         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 744         .set_port               = xprt_rdma_set_port,
 745         .connect                = xprt_rdma_connect,
 746         .buf_alloc              = xprt_rdma_allocate,
 747         .buf_free               = xprt_rdma_free,
 748         .send_request           = xprt_rdma_send_request,
 749         .close                  = xprt_rdma_close,
 750         .destroy                = xprt_rdma_destroy,
 751         .set_connect_timeout    = xprt_rdma_set_connect_timeout,
 752         .print_stats            = xprt_rdma_print_stats,
 753         .enable_swap            = xprt_rdma_enable_swap,
 754         .disable_swap           = xprt_rdma_disable_swap,
 755         .inject_disconnect      = xprt_rdma_inject_disconnect,
 756 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 757         .bc_setup               = xprt_rdma_bc_setup,
 758         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 759         .bc_num_slots           = xprt_rdma_bc_max_slots,
 760         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 761         .bc_destroy             = xprt_rdma_bc_destroy,
 762 #endif
 763 };
 764
 765 static struct xprt_class xprt_rdma = {
 766         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 767         .name                   = "rdma",
 768         .owner                  = THIS_MODULE,
 769         .ident                  = XPRT_TRANSPORT_RDMA,
 770         .setup                  = xprt_setup_rdma,
 771         .netid                  = { "rdma", "rdma6", "" },
 772 };
 773
 774 void xprt_rdma_cleanup(void)
 775 {
 776 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 777         if (sunrpc_table_header) {
 778                 unregister_sysctl_table(sunrpc_table_header);
 779                 sunrpc_table_header = NULL;
 780         }
 781 #endif
 782
 783         xprt_unregister_transport(&xprt_rdma);
 784         xprt_unregister_transport(&xprt_rdma_bc);
 785 }
 786
 787 int xprt_rdma_init(void)
 788 {
 789         int rc;
 790
 791         rc = xprt_register_transport(&xprt_rdma);
 792         if (rc)
 793                 return rc;
 794
 795         rc = xprt_register_transport(&xprt_rdma_bc);
 796         if (rc) {
 797                 xprt_unregister_transport(&xprt_rdma);
 798                 return rc;
 799         }
 800
 801 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 802         if (!sunrpc_table_header)
 803                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 804 #endif
 805         return 0;
 806 }