git.rot13.org Git - linux/blob - 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 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  64 # define RPCDBG_FACILITY        RPCDBG_TRANS
  65 #endif
  66
  67 /*
  68  * tunables
  69  */
  70
  71 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  72 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  73 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  74 unsigned int xprt_rdma_memreg_strategy          = RPCRDMA_FRWR;
  75 int xprt_rdma_pad_optimize;
  76
  77 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  78
  79 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  80 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  81 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  82 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  83 static unsigned int zero;
  84 static unsigned int max_padding = PAGE_SIZE;
  85 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  86 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  87 static unsigned int dummy;
  88
  89 static struct ctl_table_header *sunrpc_table_header;
  90
  91 static struct ctl_table xr_tunables_table[] = {
  92         {
  93                 .procname       = "rdma_slot_table_entries",
  94                 .data           = &xprt_rdma_slot_table_entries,
  95                 .maxlen         = sizeof(unsigned int),
  96                 .mode           = 0644,
  97                 .proc_handler   = proc_dointvec_minmax,
  98                 .extra1         = &min_slot_table_size,
  99                 .extra2         = &max_slot_table_size
 100         },
 101         {
 102                 .procname       = "rdma_max_inline_read",
 103                 .data           = &xprt_rdma_max_inline_read,
 104                 .maxlen         = sizeof(unsigned int),
 105                 .mode           = 0644,
 106                 .proc_handler   = proc_dointvec_minmax,
 107                 .extra1         = &min_inline_size,
 108                 .extra2         = &max_inline_size,
 109         },
 110         {
 111                 .procname       = "rdma_max_inline_write",
 112                 .data           = &xprt_rdma_max_inline_write,
 113                 .maxlen         = sizeof(unsigned int),
 114                 .mode           = 0644,
 115                 .proc_handler   = proc_dointvec_minmax,
 116                 .extra1         = &min_inline_size,
 117                 .extra2         = &max_inline_size,
 118         },
 119         {
 120                 .procname       = "rdma_inline_write_padding",
 121                 .data           = &dummy,
 122                 .maxlen         = sizeof(unsigned int),
 123                 .mode           = 0644,
 124                 .proc_handler   = proc_dointvec_minmax,
 125                 .extra1         = &zero,
 126                 .extra2         = &max_padding,
 127         },
 128         {
 129                 .procname       = "rdma_memreg_strategy",
 130                 .data           = &xprt_rdma_memreg_strategy,
 131                 .maxlen         = sizeof(unsigned int),
 132                 .mode           = 0644,
 133                 .proc_handler   = proc_dointvec_minmax,
 134                 .extra1         = &min_memreg,
 135                 .extra2         = &max_memreg,
 136         },
 137         {
 138                 .procname       = "rdma_pad_optimize",
 139                 .data           = &xprt_rdma_pad_optimize,
 140                 .maxlen         = sizeof(unsigned int),
 141                 .mode           = 0644,
 142                 .proc_handler   = proc_dointvec,
 143         },
 144         { },
 145 };
 146
 147 static struct ctl_table sunrpc_table[] = {
 148         {
 149                 .procname       = "sunrpc",
 150                 .mode           = 0555,
 151                 .child          = xr_tunables_table
 152         },
 153         { },
 154 };
 155
 156 #endif
 157
 158 static const struct rpc_xprt_ops xprt_rdma_procs;
 159
 160 static void
 161 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 162 {
 163         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 164         char buf[20];
 165
 166         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 167         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 168
 169         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 170 }
 171
 172 static void
 173 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 174 {
 175         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 176         char buf[40];
 177
 178         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 179         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 180
 181         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 182 }
 183
 184 void
 185 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 186 {
 187         char buf[128];
 188
 189         switch (sap->sa_family) {
 190         case AF_INET:
 191                 xprt_rdma_format_addresses4(xprt, sap);
 192                 break;
 193         case AF_INET6:
 194                 xprt_rdma_format_addresses6(xprt, sap);
 195                 break;
 196         default:
 197                 pr_err("rpcrdma: Unrecognized address family\n");
 198                 return;
 199         }
 200
 201         (void)rpc_ntop(sap, buf, sizeof(buf));
 202         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 203
 204         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 205         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 206
 207         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 208         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 209
 210         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 211 }
 212
 213 void
 214 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 215 {
 216         unsigned int i;
 217
 218         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 219                 switch (i) {
 220                 case RPC_DISPLAY_PROTO:
 221                 case RPC_DISPLAY_NETID:
 222                         continue;
 223                 default:
 224                         kfree(xprt->address_strings[i]);
 225                 }
 226 }
 227
 228 /**
 229  * xprt_rdma_connect_worker - establish connection in the background
 230  * @work: worker thread context
 231  *
 232  * Requester holds the xprt's send lock to prevent activity on this
 233  * transport while a fresh connection is being established. RPC tasks
 234  * sleep on the xprt's pending queue waiting for connect to complete.
 235  */
 236 static void
 237 xprt_rdma_connect_worker(struct work_struct *work)
 238 {
 239         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 240                                                    rx_connect_worker.work);
 241         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 242         int rc;
 243
 244         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 245         xprt_clear_connecting(xprt);
 246         if (r_xprt->rx_ep.rep_connected > 0) {
 247                 if (!xprt_test_and_set_connected(xprt)) {
 248                         xprt->stat.connect_count++;
 249                         xprt->stat.connect_time += (long)jiffies -
 250                                                    xprt->stat.connect_start;
 251                         xprt_wake_pending_tasks(xprt, -EAGAIN);
 252                 }
 253         } else {
 254                 if (xprt_test_and_clear_connected(xprt))
 255                         xprt_wake_pending_tasks(xprt, rc);
 256         }
 257 }
 258
 259 /**
 260  * xprt_rdma_inject_disconnect - inject a connection fault
 261  * @xprt: transport context
 262  *
 263  * If @xprt is connected, disconnect it to simulate spurious connection
 264  * loss.
 265  */
 266 static void
 267 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 268 {
 269         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 270
 271         trace_xprtrdma_op_inject_dsc(r_xprt);
 272         rdma_disconnect(r_xprt->rx_ia.ri_id);
 273 }
 274
 275 /**
 276  * xprt_rdma_destroy - Full tear down of transport
 277  * @xprt: doomed transport context
 278  *
 279  * Caller guarantees there will be no more calls to us with
 280  * this @xprt.
 281  */
 282 static void
 283 xprt_rdma_destroy(struct rpc_xprt *xprt)
 284 {
 285         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 286
 287         trace_xprtrdma_op_destroy(r_xprt);
 288
 289         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 290
 291         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 292         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 293         rpcrdma_ia_close(&r_xprt->rx_ia);
 294
 295         xprt_rdma_free_addresses(xprt);
 296         xprt_free(xprt);
 297
 298         module_put(THIS_MODULE);
 299 }
 300
 301 static const struct rpc_timeout xprt_rdma_default_timeout = {
 302         .to_initval = 60 * HZ,
 303         .to_maxval = 60 * HZ,
 304 };
 305
 306 /**
 307  * xprt_setup_rdma - Set up transport to use RDMA
 308  *
 309  * @args: rpc transport arguments
 310  */
 311 static struct rpc_xprt *
 312 xprt_setup_rdma(struct xprt_create *args)
 313 {
 314         struct rpcrdma_create_data_internal cdata;
 315         struct rpc_xprt *xprt;
 316         struct rpcrdma_xprt *new_xprt;
 317         struct rpcrdma_ep *new_ep;
 318         struct sockaddr *sap;
 319         int rc;
 320
 321         if (args->addrlen > sizeof(xprt->addr))
 322                 return ERR_PTR(-EBADF);
 323
 324         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0, 0);
 325         if (!xprt)
 326                 return ERR_PTR(-ENOMEM);
 327
 328         /* 60 second timeout, no retries */
 329         xprt->timeout = &xprt_rdma_default_timeout;
 330         xprt->bind_timeout = RPCRDMA_BIND_TO;
 331         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 332         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 333
 334         xprt->resvport = 0;             /* privileged port not needed */
 335         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 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->addrlen = args->addrlen;
 347         memcpy(&xprt->addr, sap, xprt->addrlen);
 348
 349         if (rpc_get_port(sap))
 350                 xprt_set_bound(xprt);
 351         xprt_rdma_format_addresses(xprt, sap);
 352
 353         cdata.max_requests = xprt_rdma_slot_table_entries;
 354
 355         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 356         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 357
 358         cdata.inline_wsize = xprt_rdma_max_inline_write;
 359         if (cdata.inline_wsize > cdata.wsize)
 360                 cdata.inline_wsize = cdata.wsize;
 361
 362         cdata.inline_rsize = xprt_rdma_max_inline_read;
 363         if (cdata.inline_rsize > cdata.rsize)
 364                 cdata.inline_rsize = cdata.rsize;
 365
 366         /*
 367          * Create new transport instance, which includes initialized
 368          *  o ia
 369          *  o endpoint
 370          *  o buffers
 371          */
 372
 373         new_xprt = rpcx_to_rdmax(xprt);
 374
 375         rc = rpcrdma_ia_open(new_xprt);
 376         if (rc)
 377                 goto out1;
 378
 379         /*
 380          * initialize and create ep
 381          */
 382         new_xprt->rx_data = cdata;
 383         new_ep = &new_xprt->rx_ep;
 384
 385         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 386                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 387         if (rc)
 388                 goto out2;
 389
 390         rc = rpcrdma_buffer_create(new_xprt);
 391         if (rc)
 392                 goto out3;
 393
 394         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 395                           xprt_rdma_connect_worker);
 396
 397         xprt->max_payload = frwr_maxpages(new_xprt);
 398         if (xprt->max_payload == 0)
 399                 goto out4;
 400         xprt->max_payload <<= PAGE_SHIFT;
 401         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 402                 __func__, xprt->max_payload);
 403
 404         if (!try_module_get(THIS_MODULE))
 405                 goto out4;
 406
 407         dprintk("RPC:       %s: %s:%s\n", __func__,
 408                 xprt->address_strings[RPC_DISPLAY_ADDR],
 409                 xprt->address_strings[RPC_DISPLAY_PORT]);
 410         trace_xprtrdma_create(new_xprt);
 411         return xprt;
 412
 413 out4:
 414         rpcrdma_buffer_destroy(&new_xprt->rx_buf);
 415         rc = -ENODEV;
 416 out3:
 417         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 418 out2:
 419         rpcrdma_ia_close(&new_xprt->rx_ia);
 420 out1:
 421         trace_xprtrdma_op_destroy(new_xprt);
 422         xprt_rdma_free_addresses(xprt);
 423         xprt_free(xprt);
 424         return ERR_PTR(rc);
 425 }
 426
 427 /**
 428  * xprt_rdma_close - close a transport connection
 429  * @xprt: transport context
 430  *
 431  * Called during autoclose or device removal.
 432  *
 433  * Caller holds @xprt's send lock to prevent activity on this
 434  * transport while the connection is torn down.
 435  */
 436 void xprt_rdma_close(struct rpc_xprt *xprt)
 437 {
 438         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 439         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 440         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 441
 442         might_sleep();
 443
 444         trace_xprtrdma_op_close(r_xprt);
 445
 446         /* Prevent marshaling and sending of new requests */
 447         xprt_clear_connected(xprt);
 448
 449         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 450                 rpcrdma_ia_remove(ia);
 451                 goto out;
 452         }
 453
 454         if (ep->rep_connected == -ENODEV)
 455                 return;
 456         if (ep->rep_connected > 0)
 457                 xprt->reestablish_timeout = 0;
 458         rpcrdma_ep_disconnect(ep, ia);
 459
 460         /* Prepare @xprt for the next connection by reinitializing
 461          * its credit grant to one (see RFC 8166, Section 3.3.3).
 462          */
 463         r_xprt->rx_buf.rb_credits = 1;
 464         xprt->cwnd = RPC_CWNDSHIFT;
 465
 466 out:
 467         ++xprt->connect_cookie;
 468         xprt_disconnect_done(xprt);
 469 }
 470
 471 /**
 472  * xprt_rdma_set_port - update server port with rpcbind result
 473  * @xprt: controlling RPC transport
 474  * @port: new port value
 475  *
 476  * Transport connect status is unchanged.
 477  */
 478 static void
 479 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 480 {
 481         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 482         char buf[8];
 483
 484         dprintk("RPC:       %s: setting port for xprt %p (%s:%s) to %u\n",
 485                 __func__, xprt,
 486                 xprt->address_strings[RPC_DISPLAY_ADDR],
 487                 xprt->address_strings[RPC_DISPLAY_PORT],
 488                 port);
 489
 490         rpc_set_port(sap, port);
 491
 492         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 493         snprintf(buf, sizeof(buf), "%u", port);
 494         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 495
 496         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 497         snprintf(buf, sizeof(buf), "%4hx", port);
 498         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 499 }
 500
 501 /**
 502  * xprt_rdma_timer - invoked when an RPC times out
 503  * @xprt: controlling RPC transport
 504  * @task: RPC task that timed out
 505  *
 506  * Invoked when the transport is still connected, but an RPC
 507  * retransmit timeout occurs.
 508  *
 509  * Since RDMA connections don't have a keep-alive, forcibly
 510  * disconnect and retry to connect. This drives full
 511  * detection of the network path, and retransmissions of
 512  * all pending RPCs.
 513  */
 514 static void
 515 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 516 {
 517         xprt_force_disconnect(xprt);
 518 }
 519
 520 /**
 521  * xprt_rdma_connect - try to establish a transport connection
 522  * @xprt: transport state
 523  * @task: RPC scheduler context
 524  *
 525  */
 526 static void
 527 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 528 {
 529         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 530
 531         trace_xprtrdma_op_connect(r_xprt);
 532         if (r_xprt->rx_ep.rep_connected != 0) {
 533                 /* Reconnect */
 534                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 535                                       xprt->reestablish_timeout);
 536                 xprt->reestablish_timeout <<= 1;
 537                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 538                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 539                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 540                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 541         } else {
 542                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 543                 if (!RPC_IS_ASYNC(task))
 544                         flush_delayed_work(&r_xprt->rx_connect_worker);
 545         }
 546 }
 547
 548 /**
 549  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 550  * @xprt: controlling RPC transport
 551  * @task: RPC task requesting a fresh rpc_rqst
 552  *
 553  * tk_status values:
 554  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 555  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 556  */
 557 static void
 558 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 559 {
 560         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 561         struct rpcrdma_req *req;
 562
 563         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 564         if (!req)
 565                 goto out_sleep;
 566         task->tk_rqstp = &req->rl_slot;
 567         task->tk_status = 0;
 568         return;
 569
 570 out_sleep:
 571         rpc_sleep_on(&xprt->backlog, task, NULL);
 572         task->tk_status = -EAGAIN;
 573 }
 574
 575 /**
 576  * xprt_rdma_free_slot - release an rpc_rqst
 577  * @xprt: controlling RPC transport
 578  * @rqst: rpc_rqst to release
 579  *
 580  */
 581 static void
 582 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 583 {
 584         memset(rqst, 0, sizeof(*rqst));
 585         rpcrdma_buffer_put(rpcr_to_rdmar(rqst));
 586         rpc_wake_up_next(&xprt->backlog);
 587 }
 588
 589 static bool
 590 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 591                     size_t size, gfp_t flags)
 592 {
 593         struct rpcrdma_regbuf *rb;
 594
 595         if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
 596                 return true;
 597
 598         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 599         if (IS_ERR(rb))
 600                 return false;
 601
 602         rpcrdma_free_regbuf(req->rl_sendbuf);
 603         r_xprt->rx_stats.hardway_register_count += size;
 604         req->rl_sendbuf = rb;
 605         return true;
 606 }
 607
 608 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
 609  * The decision to use a Reply chunk is made later in
 610  * rpcrdma_marshal_req. This buffer is registered at that time.
 611  *
 612  * Otherwise, the associated RPC Reply arrives in a separate
 613  * Receive buffer, arbitrarily chosen by the HCA. The buffer
 614  * allocated here for the RPC Reply is not utilized in that
 615  * case. See rpcrdma_inline_fixup.
 616  *
 617  * A regbuf is used here to remember the buffer size.
 618  */
 619 static bool
 620 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 621                     size_t size, gfp_t flags)
 622 {
 623         struct rpcrdma_regbuf *rb;
 624
 625         if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
 626                 return true;
 627
 628         rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
 629         if (IS_ERR(rb))
 630                 return false;
 631
 632         rpcrdma_free_regbuf(req->rl_recvbuf);
 633         r_xprt->rx_stats.hardway_register_count += size;
 634         req->rl_recvbuf = rb;
 635         return true;
 636 }
 637
 638 /**
 639  * xprt_rdma_allocate - allocate transport resources for an RPC
 640  * @task: RPC task
 641  *
 642  * Return values:
 643  *        0:    Success; rq_buffer points to RPC buffer to use
 644  *   ENOMEM:    Out of memory, call again later
 645  *      EIO:    A permanent error occurred, do not retry
 646  */
 647 static int
 648 xprt_rdma_allocate(struct rpc_task *task)
 649 {
 650         struct rpc_rqst *rqst = task->tk_rqstp;
 651         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 652         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 653         gfp_t flags;
 654
 655         flags = RPCRDMA_DEF_GFP;
 656         if (RPC_IS_SWAPPER(task))
 657                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 658
 659         if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
 660                 goto out_fail;
 661         if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
 662                 goto out_fail;
 663
 664         rqst->rq_buffer = req->rl_sendbuf->rg_base;
 665         rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
 666         trace_xprtrdma_op_allocate(task, req);
 667         return 0;
 668
 669 out_fail:
 670         trace_xprtrdma_op_allocate(task, NULL);
 671         return -ENOMEM;
 672 }
 673
 674 /**
 675  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 676  * @task: RPC task
 677  *
 678  * Caller guarantees rqst->rq_buffer is non-NULL.
 679  */
 680 static void
 681 xprt_rdma_free(struct rpc_task *task)
 682 {
 683         struct rpc_rqst *rqst = task->tk_rqstp;
 684         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 685         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 686
 687         if (test_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags))
 688                 rpcrdma_release_rqst(r_xprt, req);
 689         trace_xprtrdma_op_free(task, req);
 690 }
 691
 692 /**
 693  * xprt_rdma_send_request - marshal and send an RPC request
 694  * @rqst: RPC message in rq_snd_buf
 695  *
 696  * Caller holds the transport's write lock.
 697  *
 698  * Returns:
 699  *      %0 if the RPC message has been sent
 700  *      %-ENOTCONN if the caller should reconnect and call again
 701  *      %-EAGAIN if the caller should call again
 702  *      %-ENOBUFS if the caller should call again after a delay
 703  *      %-EMSGSIZE if encoding ran out of buffer space. The request
 704  *              was not sent. Do not try to send this message again.
 705  *      %-EIO if an I/O error occurred. The request was not sent.
 706  *              Do not try to send this message again.
 707  */
 708 static int
 709 xprt_rdma_send_request(struct rpc_rqst *rqst)
 710 {
 711         struct rpc_xprt *xprt = rqst->rq_xprt;
 712         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 713         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 714         int rc = 0;
 715
 716 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 717         if (unlikely(!rqst->rq_buffer))
 718                 return xprt_rdma_bc_send_reply(rqst);
 719 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 720
 721         if (!xprt_connected(xprt))
 722                 return -ENOTCONN;
 723
 724         if (!xprt_request_get_cong(xprt, rqst))
 725                 return -EBADSLT;
 726
 727         rc = rpcrdma_marshal_req(r_xprt, rqst);
 728         if (rc < 0)
 729                 goto failed_marshal;
 730
 731         /* Must suppress retransmit to maintain credits */
 732         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 733                 goto drop_connection;
 734         rqst->rq_xtime = ktime_get();
 735
 736         __set_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags);
 737         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 738                 goto drop_connection;
 739
 740         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 741         rqst->rq_bytes_sent = 0;
 742
 743         /* An RPC with no reply will throw off credit accounting,
 744          * so drop the connection to reset the credit grant.
 745          */
 746         if (!rpc_reply_expected(rqst->rq_task))
 747                 goto drop_connection;
 748         return 0;
 749
 750 failed_marshal:
 751         if (rc != -ENOTCONN)
 752                 return rc;
 753 drop_connection:
 754         xprt_rdma_close(xprt);
 755         return -ENOTCONN;
 756 }
 757
 758 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 759 {
 760         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 761         long idle_time = 0;
 762
 763         if (xprt_connected(xprt))
 764                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 765
 766         seq_puts(seq, "\txprt:\trdma ");
 767         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 768                    0,   /* need a local port? */
 769                    xprt->stat.bind_count,
 770                    xprt->stat.connect_count,
 771                    xprt->stat.connect_time / HZ,
 772                    idle_time,
 773                    xprt->stat.sends,
 774                    xprt->stat.recvs,
 775                    xprt->stat.bad_xids,
 776                    xprt->stat.req_u,
 777                    xprt->stat.bklog_u);
 778         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 779                    r_xprt->rx_stats.read_chunk_count,
 780                    r_xprt->rx_stats.write_chunk_count,
 781                    r_xprt->rx_stats.reply_chunk_count,
 782                    r_xprt->rx_stats.total_rdma_request,
 783                    r_xprt->rx_stats.total_rdma_reply,
 784                    r_xprt->rx_stats.pullup_copy_count,
 785                    r_xprt->rx_stats.fixup_copy_count,
 786                    r_xprt->rx_stats.hardway_register_count,
 787                    r_xprt->rx_stats.failed_marshal_count,
 788                    r_xprt->rx_stats.bad_reply_count,
 789                    r_xprt->rx_stats.nomsg_call_count);
 790         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 791                    r_xprt->rx_stats.mrs_recycled,
 792                    r_xprt->rx_stats.mrs_orphaned,
 793                    r_xprt->rx_stats.mrs_allocated,
 794                    r_xprt->rx_stats.local_inv_needed,
 795                    r_xprt->rx_stats.empty_sendctx_q,
 796                    r_xprt->rx_stats.reply_waits_for_send);
 797 }
 798
 799 static int
 800 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 801 {
 802         return 0;
 803 }
 804
 805 static void
 806 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 807 {
 808 }
 809
 810 /*
 811  * Plumbing for rpc transport switch and kernel module
 812  */
 813
 814 static const struct rpc_xprt_ops xprt_rdma_procs = {
 815         .reserve_xprt           = xprt_reserve_xprt_cong,
 816         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 817         .alloc_slot             = xprt_rdma_alloc_slot,
 818         .free_slot              = xprt_rdma_free_slot,
 819         .release_request        = xprt_release_rqst_cong,       /* ditto */
 820         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 821         .timer                  = xprt_rdma_timer,
 822         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 823         .set_port               = xprt_rdma_set_port,
 824         .connect                = xprt_rdma_connect,
 825         .buf_alloc              = xprt_rdma_allocate,
 826         .buf_free               = xprt_rdma_free,
 827         .send_request           = xprt_rdma_send_request,
 828         .close                  = xprt_rdma_close,
 829         .destroy                = xprt_rdma_destroy,
 830         .print_stats            = xprt_rdma_print_stats,
 831         .enable_swap            = xprt_rdma_enable_swap,
 832         .disable_swap           = xprt_rdma_disable_swap,
 833         .inject_disconnect      = xprt_rdma_inject_disconnect,
 834 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 835         .bc_setup               = xprt_rdma_bc_setup,
 836         .bc_up                  = xprt_rdma_bc_up,
 837         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 838         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 839         .bc_destroy             = xprt_rdma_bc_destroy,
 840 #endif
 841 };
 842
 843 static struct xprt_class xprt_rdma = {
 844         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 845         .name                   = "rdma",
 846         .owner                  = THIS_MODULE,
 847         .ident                  = XPRT_TRANSPORT_RDMA,
 848         .setup                  = xprt_setup_rdma,
 849 };
 850
 851 void xprt_rdma_cleanup(void)
 852 {
 853 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 854         if (sunrpc_table_header) {
 855                 unregister_sysctl_table(sunrpc_table_header);
 856                 sunrpc_table_header = NULL;
 857         }
 858 #endif
 859
 860         xprt_unregister_transport(&xprt_rdma);
 861         xprt_unregister_transport(&xprt_rdma_bc);
 862 }
 863
 864 int xprt_rdma_init(void)
 865 {
 866         int rc;
 867
 868         rc = xprt_register_transport(&xprt_rdma);
 869         if (rc)
 870                 return rc;
 871
 872         rc = xprt_register_transport(&xprt_rdma_bc);
 873         if (rc) {
 874                 xprt_unregister_transport(&xprt_rdma);
 875                 return rc;
 876         }
 877
 878 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 879         if (!sunrpc_table_header)
 880                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 881 #endif
 882         return 0;
 883 }