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