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 void
 229 rpcrdma_conn_func(struct rpcrdma_ep *ep)
 230 {
 231         schedule_delayed_work(&ep->rep_connect_worker, 0);
 232 }
 233
 234 void
 235 rpcrdma_connect_worker(struct work_struct *work)
 236 {
 237         struct rpcrdma_ep *ep =
 238                 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
 239         struct rpcrdma_xprt *r_xprt =
 240                 container_of(ep, struct rpcrdma_xprt, rx_ep);
 241         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 242
 243         spin_lock_bh(&xprt->transport_lock);
 244         if (ep->rep_connected > 0) {
 245                 if (!xprt_test_and_set_connected(xprt))
 246                         xprt_wake_pending_tasks(xprt, 0);
 247         } else {
 248                 if (xprt_test_and_clear_connected(xprt))
 249                         xprt_wake_pending_tasks(xprt, -ENOTCONN);
 250         }
 251         spin_unlock_bh(&xprt->transport_lock);
 252 }
 253
 254 static void
 255 xprt_rdma_connect_worker(struct work_struct *work)
 256 {
 257         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 258                                                    rx_connect_worker.work);
 259         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 260         int rc = 0;
 261
 262         xprt_clear_connected(xprt);
 263
 264         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 265         if (rc)
 266                 xprt_wake_pending_tasks(xprt, rc);
 267
 268         xprt_clear_connecting(xprt);
 269 }
 270
 271 static void
 272 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 273 {
 274         struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
 275                                                    rx_xprt);
 276
 277         trace_xprtrdma_inject_dsc(r_xprt);
 278         rdma_disconnect(r_xprt->rx_ia.ri_id);
 279 }
 280
 281 /*
 282  * xprt_rdma_destroy
 283  *
 284  * Destroy the xprt.
 285  * Free all memory associated with the object, including its own.
 286  * NOTE: none of the *destroy methods free memory for their top-level
 287  * objects, even though they may have allocated it (they do free
 288  * private memory). It's up to the caller to handle it. In this
 289  * case (RDMA transport), all structure memory is inlined with the
 290  * struct rpcrdma_xprt.
 291  */
 292 static void
 293 xprt_rdma_destroy(struct rpc_xprt *xprt)
 294 {
 295         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 296
 297         trace_xprtrdma_destroy(r_xprt);
 298
 299         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 300
 301         xprt_clear_connected(xprt);
 302
 303         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 304         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 305         rpcrdma_ia_close(&r_xprt->rx_ia);
 306
 307         xprt_rdma_free_addresses(xprt);
 308         xprt_free(xprt);
 309
 310         module_put(THIS_MODULE);
 311 }
 312
 313 static const struct rpc_timeout xprt_rdma_default_timeout = {
 314         .to_initval = 60 * HZ,
 315         .to_maxval = 60 * HZ,
 316 };
 317
 318 /**
 319  * xprt_setup_rdma - Set up transport to use RDMA
 320  *
 321  * @args: rpc transport arguments
 322  */
 323 static struct rpc_xprt *
 324 xprt_setup_rdma(struct xprt_create *args)
 325 {
 326         struct rpcrdma_create_data_internal cdata;
 327         struct rpc_xprt *xprt;
 328         struct rpcrdma_xprt *new_xprt;
 329         struct rpcrdma_ep *new_ep;
 330         struct sockaddr *sap;
 331         int rc;
 332
 333         if (args->addrlen > sizeof(xprt->addr)) {
 334                 dprintk("RPC:       %s: address too large\n", __func__);
 335                 return ERR_PTR(-EBADF);
 336         }
 337
 338         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0, 0);
 339         if (xprt == NULL) {
 340                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 341                         __func__);
 342                 return ERR_PTR(-ENOMEM);
 343         }
 344
 345         /* 60 second timeout, no retries */
 346         xprt->timeout = &xprt_rdma_default_timeout;
 347         xprt->bind_timeout = RPCRDMA_BIND_TO;
 348         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 349         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 350
 351         xprt->resvport = 0;             /* privileged port not needed */
 352         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 353         xprt->ops = &xprt_rdma_procs;
 354
 355         /*
 356          * Set up RDMA-specific connect data.
 357          */
 358         sap = args->dstaddr;
 359
 360         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 361          * address, for any side protocols which peek at it */
 362         xprt->prot = IPPROTO_TCP;
 363         xprt->addrlen = args->addrlen;
 364         memcpy(&xprt->addr, sap, xprt->addrlen);
 365
 366         if (rpc_get_port(sap))
 367                 xprt_set_bound(xprt);
 368         xprt_rdma_format_addresses(xprt, sap);
 369
 370         cdata.max_requests = xprt_rdma_slot_table_entries;
 371
 372         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 373         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 374
 375         cdata.inline_wsize = xprt_rdma_max_inline_write;
 376         if (cdata.inline_wsize > cdata.wsize)
 377                 cdata.inline_wsize = cdata.wsize;
 378
 379         cdata.inline_rsize = xprt_rdma_max_inline_read;
 380         if (cdata.inline_rsize > cdata.rsize)
 381                 cdata.inline_rsize = cdata.rsize;
 382
 383         /*
 384          * Create new transport instance, which includes initialized
 385          *  o ia
 386          *  o endpoint
 387          *  o buffers
 388          */
 389
 390         new_xprt = rpcx_to_rdmax(xprt);
 391
 392         rc = rpcrdma_ia_open(new_xprt);
 393         if (rc)
 394                 goto out1;
 395
 396         /*
 397          * initialize and create ep
 398          */
 399         new_xprt->rx_data = cdata;
 400         new_ep = &new_xprt->rx_ep;
 401
 402         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 403                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 404         if (rc)
 405                 goto out2;
 406
 407         rc = rpcrdma_buffer_create(new_xprt);
 408         if (rc)
 409                 goto out3;
 410
 411         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 412                           xprt_rdma_connect_worker);
 413
 414         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 415         if (xprt->max_payload == 0)
 416                 goto out4;
 417         xprt->max_payload <<= PAGE_SHIFT;
 418         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 419                 __func__, xprt->max_payload);
 420
 421         if (!try_module_get(THIS_MODULE))
 422                 goto out4;
 423
 424         dprintk("RPC:       %s: %s:%s\n", __func__,
 425                 xprt->address_strings[RPC_DISPLAY_ADDR],
 426                 xprt->address_strings[RPC_DISPLAY_PORT]);
 427         trace_xprtrdma_create(new_xprt);
 428         return xprt;
 429
 430 out4:
 431         rpcrdma_buffer_destroy(&new_xprt->rx_buf);
 432         rc = -ENODEV;
 433 out3:
 434         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 435 out2:
 436         rpcrdma_ia_close(&new_xprt->rx_ia);
 437 out1:
 438         trace_xprtrdma_destroy(new_xprt);
 439         xprt_rdma_free_addresses(xprt);
 440         xprt_free(xprt);
 441         return ERR_PTR(rc);
 442 }
 443
 444 /**
 445  * xprt_rdma_close - Close down RDMA connection
 446  * @xprt: generic transport to be closed
 447  *
 448  * Called during transport shutdown reconnect, or device
 449  * removal. Caller holds the transport's write lock.
 450  */
 451 static void
 452 xprt_rdma_close(struct rpc_xprt *xprt)
 453 {
 454         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 455         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 456         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 457
 458         dprintk("RPC:       %s: closing xprt %p\n", __func__, xprt);
 459
 460         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 461                 xprt_clear_connected(xprt);
 462                 rpcrdma_ia_remove(ia);
 463                 return;
 464         }
 465         if (ep->rep_connected == -ENODEV)
 466                 return;
 467         if (ep->rep_connected > 0)
 468                 xprt->reestablish_timeout = 0;
 469         xprt_disconnect_done(xprt);
 470         rpcrdma_ep_disconnect(ep, ia);
 471
 472         /* Prepare @xprt for the next connection by reinitializing
 473          * its credit grant to one (see RFC 8166, Section 3.3.3).
 474          */
 475         r_xprt->rx_buf.rb_credits = 1;
 476         xprt->cwnd = RPC_CWNDSHIFT;
 477 }
 478
 479 /**
 480  * xprt_rdma_set_port - update server port with rpcbind result
 481  * @xprt: controlling RPC transport
 482  * @port: new port value
 483  *
 484  * Transport connect status is unchanged.
 485  */
 486 static void
 487 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 488 {
 489         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 490         char buf[8];
 491
 492         dprintk("RPC:       %s: setting port for xprt %p (%s:%s) to %u\n",
 493                 __func__, xprt,
 494                 xprt->address_strings[RPC_DISPLAY_ADDR],
 495                 xprt->address_strings[RPC_DISPLAY_PORT],
 496                 port);
 497
 498         rpc_set_port(sap, port);
 499
 500         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 501         snprintf(buf, sizeof(buf), "%u", port);
 502         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 503
 504         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 505         snprintf(buf, sizeof(buf), "%4hx", port);
 506         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 507 }
 508
 509 /**
 510  * xprt_rdma_timer - invoked when an RPC times out
 511  * @xprt: controlling RPC transport
 512  * @task: RPC task that timed out
 513  *
 514  * Invoked when the transport is still connected, but an RPC
 515  * retransmit timeout occurs.
 516  *
 517  * Since RDMA connections don't have a keep-alive, forcibly
 518  * disconnect and retry to connect. This drives full
 519  * detection of the network path, and retransmissions of
 520  * all pending RPCs.
 521  */
 522 static void
 523 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 524 {
 525         xprt_force_disconnect(xprt);
 526 }
 527
 528 static void
 529 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 530 {
 531         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 532
 533         if (r_xprt->rx_ep.rep_connected != 0) {
 534                 /* Reconnect */
 535                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 536                                       xprt->reestablish_timeout);
 537                 xprt->reestablish_timeout <<= 1;
 538                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 539                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 540                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 541                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 542         } else {
 543                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 544                 if (!RPC_IS_ASYNC(task))
 545                         flush_delayed_work(&r_xprt->rx_connect_worker);
 546         }
 547 }
 548
 549 /**
 550  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 551  * @xprt: controlling RPC transport
 552  * @task: RPC task requesting a fresh rpc_rqst
 553  *
 554  * tk_status values:
 555  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 556  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 557  */
 558 static void
 559 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 560 {
 561         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 562         struct rpcrdma_req *req;
 563
 564         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 565         if (!req)
 566                 goto out_sleep;
 567         task->tk_rqstp = &req->rl_slot;
 568         task->tk_status = 0;
 569         return;
 570
 571 out_sleep:
 572         rpc_sleep_on(&xprt->backlog, task, NULL);
 573         task->tk_status = -EAGAIN;
 574 }
 575
 576 /**
 577  * xprt_rdma_free_slot - release an rpc_rqst
 578  * @xprt: controlling RPC transport
 579  * @rqst: rpc_rqst to release
 580  *
 581  */
 582 static void
 583 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 584 {
 585         memset(rqst, 0, sizeof(*rqst));
 586         rpcrdma_buffer_put(rpcr_to_rdmar(rqst));
 587         rpc_wake_up_next(&xprt->backlog);
 588 }
 589
 590 static bool
 591 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 592                     size_t size, gfp_t flags)
 593 {
 594         struct rpcrdma_regbuf *rb;
 595
 596         if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
 597                 return true;
 598
 599         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 600         if (IS_ERR(rb))
 601                 return false;
 602
 603         rpcrdma_free_regbuf(req->rl_sendbuf);
 604         r_xprt->rx_stats.hardway_register_count += size;
 605         req->rl_sendbuf = rb;
 606         return true;
 607 }
 608
 609 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
 610  * The decision to use a Reply chunk is made later in
 611  * rpcrdma_marshal_req. This buffer is registered at that time.
 612  *
 613  * Otherwise, the associated RPC Reply arrives in a separate
 614  * Receive buffer, arbitrarily chosen by the HCA. The buffer
 615  * allocated here for the RPC Reply is not utilized in that
 616  * case. See rpcrdma_inline_fixup.
 617  *
 618  * A regbuf is used here to remember the buffer size.
 619  */
 620 static bool
 621 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 622                     size_t size, gfp_t flags)
 623 {
 624         struct rpcrdma_regbuf *rb;
 625
 626         if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
 627                 return true;
 628
 629         rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
 630         if (IS_ERR(rb))
 631                 return false;
 632
 633         rpcrdma_free_regbuf(req->rl_recvbuf);
 634         r_xprt->rx_stats.hardway_register_count += size;
 635         req->rl_recvbuf = rb;
 636         return true;
 637 }
 638
 639 /**
 640  * xprt_rdma_allocate - allocate transport resources for an RPC
 641  * @task: RPC task
 642  *
 643  * Return values:
 644  *        0:    Success; rq_buffer points to RPC buffer to use
 645  *   ENOMEM:    Out of memory, call again later
 646  *      EIO:    A permanent error occurred, do not retry
 647  *
 648  * The RDMA allocate/free functions need the task structure as a place
 649  * to hide the struct rpcrdma_req, which is necessary for the actual
 650  * send/recv sequence.
 651  *
 652  * xprt_rdma_allocate provides buffers that are already mapped for
 653  * DMA, and a local DMA lkey is provided for each.
 654  */
 655 static int
 656 xprt_rdma_allocate(struct rpc_task *task)
 657 {
 658         struct rpc_rqst *rqst = task->tk_rqstp;
 659         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 660         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 661         gfp_t flags;
 662
 663         flags = RPCRDMA_DEF_GFP;
 664         if (RPC_IS_SWAPPER(task))
 665                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 666
 667         if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
 668                 goto out_fail;
 669         if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
 670                 goto out_fail;
 671
 672         rqst->rq_buffer = req->rl_sendbuf->rg_base;
 673         rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
 674         trace_xprtrdma_allocate(task, req);
 675         return 0;
 676
 677 out_fail:
 678         trace_xprtrdma_allocate(task, NULL);
 679         return -ENOMEM;
 680 }
 681
 682 /**
 683  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 684  * @task: RPC task
 685  *
 686  * Caller guarantees rqst->rq_buffer is non-NULL.
 687  */
 688 static void
 689 xprt_rdma_free(struct rpc_task *task)
 690 {
 691         struct rpc_rqst *rqst = task->tk_rqstp;
 692         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 693         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 694
 695         if (test_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags))
 696                 rpcrdma_release_rqst(r_xprt, req);
 697         trace_xprtrdma_rpc_done(task, req);
 698 }
 699
 700 /**
 701  * xprt_rdma_send_request - marshal and send an RPC request
 702  * @task: RPC task with an RPC message in rq_snd_buf
 703  *
 704  * Caller holds the transport's write lock.
 705  *
 706  * Returns:
 707  *      %0 if the RPC message has been sent
 708  *      %-ENOTCONN if the caller should reconnect and call again
 709  *      %-EAGAIN if the caller should call again
 710  *      %-ENOBUFS if the caller should call again after a delay
 711  *      %-EIO if a permanent error occurred and the request was not
 712  *              sent. Do not try to send this message again.
 713  */
 714 static int
 715 xprt_rdma_send_request(struct rpc_task *task)
 716 {
 717         struct rpc_rqst *rqst = task->tk_rqstp;
 718         struct rpc_xprt *xprt = rqst->rq_xprt;
 719         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 720         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 721         int rc = 0;
 722
 723 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 724         if (unlikely(!rqst->rq_buffer))
 725                 return xprt_rdma_bc_send_reply(rqst);
 726 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 727
 728         if (!xprt_connected(xprt))
 729                 goto drop_connection;
 730
 731         rc = rpcrdma_marshal_req(r_xprt, rqst);
 732         if (rc < 0)
 733                 goto failed_marshal;
 734
 735         /* Must suppress retransmit to maintain credits */
 736         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 737                 goto drop_connection;
 738         rqst->rq_xtime = ktime_get();
 739
 740         __set_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags);
 741         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 742                 goto drop_connection;
 743
 744         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 745         rqst->rq_bytes_sent = 0;
 746
 747         /* An RPC with no reply will throw off credit accounting,
 748          * so drop the connection to reset the credit grant.
 749          */
 750         if (!rpc_reply_expected(task))
 751                 goto drop_connection;
 752         return 0;
 753
 754 failed_marshal:
 755         if (rc != -ENOTCONN)
 756                 return rc;
 757 drop_connection:
 758         xprt_disconnect_done(xprt);
 759         return -ENOTCONN;       /* implies disconnect */
 760 }
 761
 762 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 763 {
 764         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 765         long idle_time = 0;
 766
 767         if (xprt_connected(xprt))
 768                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 769
 770         seq_puts(seq, "\txprt:\trdma ");
 771         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 772                    0,   /* need a local port? */
 773                    xprt->stat.bind_count,
 774                    xprt->stat.connect_count,
 775                    xprt->stat.connect_time,
 776                    idle_time,
 777                    xprt->stat.sends,
 778                    xprt->stat.recvs,
 779                    xprt->stat.bad_xids,
 780                    xprt->stat.req_u,
 781                    xprt->stat.bklog_u);
 782         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 783                    r_xprt->rx_stats.read_chunk_count,
 784                    r_xprt->rx_stats.write_chunk_count,
 785                    r_xprt->rx_stats.reply_chunk_count,
 786                    r_xprt->rx_stats.total_rdma_request,
 787                    r_xprt->rx_stats.total_rdma_reply,
 788                    r_xprt->rx_stats.pullup_copy_count,
 789                    r_xprt->rx_stats.fixup_copy_count,
 790                    r_xprt->rx_stats.hardway_register_count,
 791                    r_xprt->rx_stats.failed_marshal_count,
 792                    r_xprt->rx_stats.bad_reply_count,
 793                    r_xprt->rx_stats.nomsg_call_count);
 794         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 795                    r_xprt->rx_stats.mrs_recovered,
 796                    r_xprt->rx_stats.mrs_orphaned,
 797                    r_xprt->rx_stats.mrs_allocated,
 798                    r_xprt->rx_stats.local_inv_needed,
 799                    r_xprt->rx_stats.empty_sendctx_q,
 800                    r_xprt->rx_stats.reply_waits_for_send);
 801 }
 802
 803 static int
 804 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 805 {
 806         return 0;
 807 }
 808
 809 static void
 810 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 811 {
 812 }
 813
 814 /*
 815  * Plumbing for rpc transport switch and kernel module
 816  */
 817
 818 static const struct rpc_xprt_ops xprt_rdma_procs = {
 819         .reserve_xprt           = xprt_reserve_xprt_cong,
 820         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 821         .alloc_slot             = xprt_rdma_alloc_slot,
 822         .free_slot              = xprt_rdma_free_slot,
 823         .release_request        = xprt_release_rqst_cong,       /* ditto */
 824         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 825         .timer                  = xprt_rdma_timer,
 826         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 827         .set_port               = xprt_rdma_set_port,
 828         .connect                = xprt_rdma_connect,
 829         .buf_alloc              = xprt_rdma_allocate,
 830         .buf_free               = xprt_rdma_free,
 831         .send_request           = xprt_rdma_send_request,
 832         .close                  = xprt_rdma_close,
 833         .destroy                = xprt_rdma_destroy,
 834         .print_stats            = xprt_rdma_print_stats,
 835         .enable_swap            = xprt_rdma_enable_swap,
 836         .disable_swap           = xprt_rdma_disable_swap,
 837         .inject_disconnect      = xprt_rdma_inject_disconnect,
 838 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 839         .bc_setup               = xprt_rdma_bc_setup,
 840         .bc_up                  = xprt_rdma_bc_up,
 841         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 842         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 843         .bc_destroy             = xprt_rdma_bc_destroy,
 844 #endif
 845 };
 846
 847 static struct xprt_class xprt_rdma = {
 848         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 849         .name                   = "rdma",
 850         .owner                  = THIS_MODULE,
 851         .ident                  = XPRT_TRANSPORT_RDMA,
 852         .setup                  = xprt_setup_rdma,
 853 };
 854
 855 void xprt_rdma_cleanup(void)
 856 {
 857         int rc;
 858
 859         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 860 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 861         if (sunrpc_table_header) {
 862                 unregister_sysctl_table(sunrpc_table_header);
 863                 sunrpc_table_header = NULL;
 864         }
 865 #endif
 866         rc = xprt_unregister_transport(&xprt_rdma);
 867         if (rc)
 868                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 869                         __func__, rc);
 870
 871         rpcrdma_destroy_wq();
 872
 873         rc = xprt_unregister_transport(&xprt_rdma_bc);
 874         if (rc)
 875                 dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
 876                         __func__, rc);
 877 }
 878
 879 int xprt_rdma_init(void)
 880 {
 881         int rc;
 882
 883         rc = rpcrdma_alloc_wq();
 884         if (rc)
 885                 return rc;
 886
 887         rc = xprt_register_transport(&xprt_rdma);
 888         if (rc) {
 889                 rpcrdma_destroy_wq();
 890                 return rc;
 891         }
 892
 893         rc = xprt_register_transport(&xprt_rdma_bc);
 894         if (rc) {
 895                 xprt_unregister_transport(&xprt_rdma);
 896                 rpcrdma_destroy_wq();
 897                 return rc;
 898         }
 899
 900         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 901
 902         dprintk("Defaults:\n");
 903         dprintk("\tSlots %d\n"
 904                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 905                 xprt_rdma_slot_table_entries,
 906                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 907         dprintk("\tPadding 0\n\tMemreg %d\n", xprt_rdma_memreg_strategy);
 908
 909 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 910         if (!sunrpc_table_header)
 911                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 912 #endif
 913         return 0;
 914 }