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_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_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                 dprintk("RPC:       %s: address too large\n", __func__);
 323                 return ERR_PTR(-EBADF);
 324         }
 325
 326         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0, 0);
 327         if (xprt == NULL) {
 328                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 329                         __func__);
 330                 return ERR_PTR(-ENOMEM);
 331         }
 332
 333         /* 60 second timeout, no retries */
 334         xprt->timeout = &xprt_rdma_default_timeout;
 335         xprt->bind_timeout = RPCRDMA_BIND_TO;
 336         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 337         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 338
 339         xprt->resvport = 0;             /* privileged port not needed */
 340         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 341         xprt->ops = &xprt_rdma_procs;
 342
 343         /*
 344          * Set up RDMA-specific connect data.
 345          */
 346         sap = args->dstaddr;
 347
 348         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 349          * address, for any side protocols which peek at it */
 350         xprt->prot = IPPROTO_TCP;
 351         xprt->addrlen = args->addrlen;
 352         memcpy(&xprt->addr, sap, xprt->addrlen);
 353
 354         if (rpc_get_port(sap))
 355                 xprt_set_bound(xprt);
 356         xprt_rdma_format_addresses(xprt, sap);
 357
 358         cdata.max_requests = xprt_rdma_slot_table_entries;
 359
 360         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 361         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 362
 363         cdata.inline_wsize = xprt_rdma_max_inline_write;
 364         if (cdata.inline_wsize > cdata.wsize)
 365                 cdata.inline_wsize = cdata.wsize;
 366
 367         cdata.inline_rsize = xprt_rdma_max_inline_read;
 368         if (cdata.inline_rsize > cdata.rsize)
 369                 cdata.inline_rsize = cdata.rsize;
 370
 371         /*
 372          * Create new transport instance, which includes initialized
 373          *  o ia
 374          *  o endpoint
 375          *  o buffers
 376          */
 377
 378         new_xprt = rpcx_to_rdmax(xprt);
 379
 380         rc = rpcrdma_ia_open(new_xprt);
 381         if (rc)
 382                 goto out1;
 383
 384         /*
 385          * initialize and create ep
 386          */
 387         new_xprt->rx_data = cdata;
 388         new_ep = &new_xprt->rx_ep;
 389
 390         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 391                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 392         if (rc)
 393                 goto out2;
 394
 395         rc = rpcrdma_buffer_create(new_xprt);
 396         if (rc)
 397                 goto out3;
 398
 399         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 400                           xprt_rdma_connect_worker);
 401
 402         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 403         if (xprt->max_payload == 0)
 404                 goto out4;
 405         xprt->max_payload <<= PAGE_SHIFT;
 406         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 407                 __func__, xprt->max_payload);
 408
 409         if (!try_module_get(THIS_MODULE))
 410                 goto out4;
 411
 412         dprintk("RPC:       %s: %s:%s\n", __func__,
 413                 xprt->address_strings[RPC_DISPLAY_ADDR],
 414                 xprt->address_strings[RPC_DISPLAY_PORT]);
 415         trace_xprtrdma_create(new_xprt);
 416         return xprt;
 417
 418 out4:
 419         rpcrdma_buffer_destroy(&new_xprt->rx_buf);
 420         rc = -ENODEV;
 421 out3:
 422         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 423 out2:
 424         rpcrdma_ia_close(&new_xprt->rx_ia);
 425 out1:
 426         trace_xprtrdma_destroy(new_xprt);
 427         xprt_rdma_free_addresses(xprt);
 428         xprt_free(xprt);
 429         return ERR_PTR(rc);
 430 }
 431
 432 /**
 433  * xprt_rdma_close - close a transport connection
 434  * @xprt: transport context
 435  *
 436  * Called during transport shutdown, reconnect, or device removal.
 437  * Caller holds @xprt's send lock to prevent activity on this
 438  * transport while the connection is torn down.
 439  */
 440 static void
 441 xprt_rdma_close(struct rpc_xprt *xprt)
 442 {
 443         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 444         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 445         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 446
 447         dprintk("RPC:       %s: closing xprt %p\n", __func__, xprt);
 448
 449         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 450                 xprt_clear_connected(xprt);
 451                 rpcrdma_ia_remove(ia);
 452                 return;
 453         }
 454         if (ep->rep_connected == -ENODEV)
 455                 return;
 456         if (ep->rep_connected > 0)
 457                 xprt->reestablish_timeout = 0;
 458         xprt_disconnect_done(xprt);
 459         rpcrdma_ep_disconnect(ep, ia);
 460
 461         /* Prepare @xprt for the next connection by reinitializing
 462          * its credit grant to one (see RFC 8166, Section 3.3.3).
 463          */
 464         r_xprt->rx_buf.rb_credits = 1;
 465         xprt->cwnd = RPC_CWNDSHIFT;
 466 }
 467
 468 /**
 469  * xprt_rdma_set_port - update server port with rpcbind result
 470  * @xprt: controlling RPC transport
 471  * @port: new port value
 472  *
 473  * Transport connect status is unchanged.
 474  */
 475 static void
 476 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 477 {
 478         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 479         char buf[8];
 480
 481         dprintk("RPC:       %s: setting port for xprt %p (%s:%s) to %u\n",
 482                 __func__, xprt,
 483                 xprt->address_strings[RPC_DISPLAY_ADDR],
 484                 xprt->address_strings[RPC_DISPLAY_PORT],
 485                 port);
 486
 487         rpc_set_port(sap, port);
 488
 489         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 490         snprintf(buf, sizeof(buf), "%u", port);
 491         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 492
 493         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 494         snprintf(buf, sizeof(buf), "%4hx", port);
 495         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 496 }
 497
 498 /**
 499  * xprt_rdma_timer - invoked when an RPC times out
 500  * @xprt: controlling RPC transport
 501  * @task: RPC task that timed out
 502  *
 503  * Invoked when the transport is still connected, but an RPC
 504  * retransmit timeout occurs.
 505  *
 506  * Since RDMA connections don't have a keep-alive, forcibly
 507  * disconnect and retry to connect. This drives full
 508  * detection of the network path, and retransmissions of
 509  * all pending RPCs.
 510  */
 511 static void
 512 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 513 {
 514         xprt_force_disconnect(xprt);
 515 }
 516
 517 /**
 518  * xprt_rdma_connect - try to establish a transport connection
 519  * @xprt: transport state
 520  * @task: RPC scheduler context
 521  *
 522  */
 523 static void
 524 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 525 {
 526         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 527
 528         if (r_xprt->rx_ep.rep_connected != 0) {
 529                 /* Reconnect */
 530                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 531                                       xprt->reestablish_timeout);
 532                 xprt->reestablish_timeout <<= 1;
 533                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 534                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 535                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 536                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 537         } else {
 538                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 539                 if (!RPC_IS_ASYNC(task))
 540                         flush_delayed_work(&r_xprt->rx_connect_worker);
 541         }
 542 }
 543
 544 /**
 545  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 546  * @xprt: controlling RPC transport
 547  * @task: RPC task requesting a fresh rpc_rqst
 548  *
 549  * tk_status values:
 550  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 551  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 552  */
 553 static void
 554 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 555 {
 556         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 557         struct rpcrdma_req *req;
 558
 559         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 560         if (!req)
 561                 goto out_sleep;
 562         task->tk_rqstp = &req->rl_slot;
 563         task->tk_status = 0;
 564         return;
 565
 566 out_sleep:
 567         rpc_sleep_on(&xprt->backlog, task, NULL);
 568         task->tk_status = -EAGAIN;
 569 }
 570
 571 /**
 572  * xprt_rdma_free_slot - release an rpc_rqst
 573  * @xprt: controlling RPC transport
 574  * @rqst: rpc_rqst to release
 575  *
 576  */
 577 static void
 578 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 579 {
 580         memset(rqst, 0, sizeof(*rqst));
 581         rpcrdma_buffer_put(rpcr_to_rdmar(rqst));
 582         rpc_wake_up_next(&xprt->backlog);
 583 }
 584
 585 static bool
 586 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 587                     size_t size, gfp_t flags)
 588 {
 589         struct rpcrdma_regbuf *rb;
 590
 591         if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
 592                 return true;
 593
 594         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 595         if (IS_ERR(rb))
 596                 return false;
 597
 598         rpcrdma_free_regbuf(req->rl_sendbuf);
 599         r_xprt->rx_stats.hardway_register_count += size;
 600         req->rl_sendbuf = rb;
 601         return true;
 602 }
 603
 604 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
 605  * The decision to use a Reply chunk is made later in
 606  * rpcrdma_marshal_req. This buffer is registered at that time.
 607  *
 608  * Otherwise, the associated RPC Reply arrives in a separate
 609  * Receive buffer, arbitrarily chosen by the HCA. The buffer
 610  * allocated here for the RPC Reply is not utilized in that
 611  * case. See rpcrdma_inline_fixup.
 612  *
 613  * A regbuf is used here to remember the buffer size.
 614  */
 615 static bool
 616 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 617                     size_t size, gfp_t flags)
 618 {
 619         struct rpcrdma_regbuf *rb;
 620
 621         if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
 622                 return true;
 623
 624         rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
 625         if (IS_ERR(rb))
 626                 return false;
 627
 628         rpcrdma_free_regbuf(req->rl_recvbuf);
 629         r_xprt->rx_stats.hardway_register_count += size;
 630         req->rl_recvbuf = rb;
 631         return true;
 632 }
 633
 634 /**
 635  * xprt_rdma_allocate - allocate transport resources for an RPC
 636  * @task: RPC task
 637  *
 638  * Return values:
 639  *        0:    Success; rq_buffer points to RPC buffer to use
 640  *   ENOMEM:    Out of memory, call again later
 641  *      EIO:    A permanent error occurred, do not retry
 642  */
 643 static int
 644 xprt_rdma_allocate(struct rpc_task *task)
 645 {
 646         struct rpc_rqst *rqst = task->tk_rqstp;
 647         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 648         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 649         gfp_t flags;
 650
 651         flags = RPCRDMA_DEF_GFP;
 652         if (RPC_IS_SWAPPER(task))
 653                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 654
 655         if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
 656                 goto out_fail;
 657         if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
 658                 goto out_fail;
 659
 660         rqst->rq_buffer = req->rl_sendbuf->rg_base;
 661         rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
 662         trace_xprtrdma_allocate(task, req);
 663         return 0;
 664
 665 out_fail:
 666         trace_xprtrdma_allocate(task, NULL);
 667         return -ENOMEM;
 668 }
 669
 670 /**
 671  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 672  * @task: RPC task
 673  *
 674  * Caller guarantees rqst->rq_buffer is non-NULL.
 675  */
 676 static void
 677 xprt_rdma_free(struct rpc_task *task)
 678 {
 679         struct rpc_rqst *rqst = task->tk_rqstp;
 680         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 681         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 682
 683         if (test_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags))
 684                 rpcrdma_release_rqst(r_xprt, req);
 685         trace_xprtrdma_rpc_done(task, req);
 686 }
 687
 688 /**
 689  * xprt_rdma_send_request - marshal and send an RPC request
 690  * @rqst: RPC message in rq_snd_buf
 691  *
 692  * Caller holds the transport's write lock.
 693  *
 694  * Returns:
 695  *      %0 if the RPC message has been sent
 696  *      %-ENOTCONN if the caller should reconnect and call again
 697  *      %-EAGAIN if the caller should call again
 698  *      %-ENOBUFS if the caller should call again after a delay
 699  *      %-EIO if a permanent error occurred and the request was not
 700  *              sent. Do not try to send this message again.
 701  */
 702 static int
 703 xprt_rdma_send_request(struct rpc_rqst *rqst)
 704 {
 705         struct rpc_xprt *xprt = rqst->rq_xprt;
 706         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 707         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 708         int rc = 0;
 709
 710 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 711         if (unlikely(!rqst->rq_buffer))
 712                 return xprt_rdma_bc_send_reply(rqst);
 713 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 714
 715         if (!xprt_connected(xprt))
 716                 goto drop_connection;
 717
 718         if (!xprt_request_get_cong(xprt, rqst))
 719                 return -EBADSLT;
 720
 721         rc = rpcrdma_marshal_req(r_xprt, rqst);
 722         if (rc < 0)
 723                 goto failed_marshal;
 724
 725         /* Must suppress retransmit to maintain credits */
 726         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 727                 goto drop_connection;
 728         rqst->rq_xtime = ktime_get();
 729
 730         __set_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags);
 731         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 732                 goto drop_connection;
 733
 734         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 735         rqst->rq_bytes_sent = 0;
 736
 737         /* An RPC with no reply will throw off credit accounting,
 738          * so drop the connection to reset the credit grant.
 739          */
 740         if (!rpc_reply_expected(rqst->rq_task))
 741                 goto drop_connection;
 742         return 0;
 743
 744 failed_marshal:
 745         if (rc != -ENOTCONN)
 746                 return rc;
 747 drop_connection:
 748         xprt_disconnect_done(xprt);
 749         return -ENOTCONN;       /* implies disconnect */
 750 }
 751
 752 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 753 {
 754         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 755         long idle_time = 0;
 756
 757         if (xprt_connected(xprt))
 758                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 759
 760         seq_puts(seq, "\txprt:\trdma ");
 761         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 762                    0,   /* need a local port? */
 763                    xprt->stat.bind_count,
 764                    xprt->stat.connect_count,
 765                    xprt->stat.connect_time / HZ,
 766                    idle_time,
 767                    xprt->stat.sends,
 768                    xprt->stat.recvs,
 769                    xprt->stat.bad_xids,
 770                    xprt->stat.req_u,
 771                    xprt->stat.bklog_u);
 772         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 773                    r_xprt->rx_stats.read_chunk_count,
 774                    r_xprt->rx_stats.write_chunk_count,
 775                    r_xprt->rx_stats.reply_chunk_count,
 776                    r_xprt->rx_stats.total_rdma_request,
 777                    r_xprt->rx_stats.total_rdma_reply,
 778                    r_xprt->rx_stats.pullup_copy_count,
 779                    r_xprt->rx_stats.fixup_copy_count,
 780                    r_xprt->rx_stats.hardway_register_count,
 781                    r_xprt->rx_stats.failed_marshal_count,
 782                    r_xprt->rx_stats.bad_reply_count,
 783                    r_xprt->rx_stats.nomsg_call_count);
 784         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 785                    r_xprt->rx_stats.mrs_recycled,
 786                    r_xprt->rx_stats.mrs_orphaned,
 787                    r_xprt->rx_stats.mrs_allocated,
 788                    r_xprt->rx_stats.local_inv_needed,
 789                    r_xprt->rx_stats.empty_sendctx_q,
 790                    r_xprt->rx_stats.reply_waits_for_send);
 791 }
 792
 793 static int
 794 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 795 {
 796         return 0;
 797 }
 798
 799 static void
 800 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 801 {
 802 }
 803
 804 /*
 805  * Plumbing for rpc transport switch and kernel module
 806  */
 807
 808 static const struct rpc_xprt_ops xprt_rdma_procs = {
 809         .reserve_xprt           = xprt_reserve_xprt_cong,
 810         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 811         .alloc_slot             = xprt_rdma_alloc_slot,
 812         .free_slot              = xprt_rdma_free_slot,
 813         .release_request        = xprt_release_rqst_cong,       /* ditto */
 814         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 815         .timer                  = xprt_rdma_timer,
 816         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 817         .set_port               = xprt_rdma_set_port,
 818         .connect                = xprt_rdma_connect,
 819         .buf_alloc              = xprt_rdma_allocate,
 820         .buf_free               = xprt_rdma_free,
 821         .send_request           = xprt_rdma_send_request,
 822         .close                  = xprt_rdma_close,
 823         .destroy                = xprt_rdma_destroy,
 824         .print_stats            = xprt_rdma_print_stats,
 825         .enable_swap            = xprt_rdma_enable_swap,
 826         .disable_swap           = xprt_rdma_disable_swap,
 827         .inject_disconnect      = xprt_rdma_inject_disconnect,
 828 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 829         .bc_setup               = xprt_rdma_bc_setup,
 830         .bc_up                  = xprt_rdma_bc_up,
 831         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 832         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 833         .bc_destroy             = xprt_rdma_bc_destroy,
 834 #endif
 835 };
 836
 837 static struct xprt_class xprt_rdma = {
 838         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 839         .name                   = "rdma",
 840         .owner                  = THIS_MODULE,
 841         .ident                  = XPRT_TRANSPORT_RDMA,
 842         .setup                  = xprt_setup_rdma,
 843 };
 844
 845 void xprt_rdma_cleanup(void)
 846 {
 847         int rc;
 848
 849         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 850 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 851         if (sunrpc_table_header) {
 852                 unregister_sysctl_table(sunrpc_table_header);
 853                 sunrpc_table_header = NULL;
 854         }
 855 #endif
 856         rc = xprt_unregister_transport(&xprt_rdma);
 857         if (rc)
 858                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 859                         __func__, rc);
 860
 861         rpcrdma_destroy_wq();
 862
 863         rc = xprt_unregister_transport(&xprt_rdma_bc);
 864         if (rc)
 865                 dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
 866                         __func__, rc);
 867 }
 868
 869 int xprt_rdma_init(void)
 870 {
 871         int rc;
 872
 873         rc = rpcrdma_alloc_wq();
 874         if (rc)
 875                 return rc;
 876
 877         rc = xprt_register_transport(&xprt_rdma);
 878         if (rc) {
 879                 rpcrdma_destroy_wq();
 880                 return rc;
 881         }
 882
 883         rc = xprt_register_transport(&xprt_rdma_bc);
 884         if (rc) {
 885                 xprt_unregister_transport(&xprt_rdma);
 886                 rpcrdma_destroy_wq();
 887                 return rc;
 888         }
 889
 890         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 891
 892         dprintk("Defaults:\n");
 893         dprintk("\tSlots %d\n"
 894                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 895                 xprt_rdma_slot_table_entries,
 896                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 897         dprintk("\tPadding 0\n\tMemreg %d\n", xprt_rdma_memreg_strategy);
 898
 899 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 900         if (!sunrpc_table_header)
 901                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 902 #endif
 903         return 0;
 904 }