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 unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  72 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  73 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);
 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 rpc_xprt *xprt;
 315         struct rpcrdma_xprt *new_xprt;
 316         struct sockaddr *sap;
 317         int rc;
 318
 319         if (args->addrlen > sizeof(xprt->addr))
 320                 return ERR_PTR(-EBADF);
 321
 322         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0, 0);
 323         if (!xprt)
 324                 return ERR_PTR(-ENOMEM);
 325
 326         /* 60 second timeout, no retries */
 327         xprt->timeout = &xprt_rdma_default_timeout;
 328         xprt->bind_timeout = RPCRDMA_BIND_TO;
 329         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 330         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 331
 332         xprt->resvport = 0;             /* privileged port not needed */
 333         xprt->ops = &xprt_rdma_procs;
 334
 335         /*
 336          * Set up RDMA-specific connect data.
 337          */
 338         sap = args->dstaddr;
 339
 340         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 341          * address, for any side protocols which peek at it */
 342         xprt->prot = IPPROTO_TCP;
 343         xprt->addrlen = args->addrlen;
 344         memcpy(&xprt->addr, sap, xprt->addrlen);
 345
 346         if (rpc_get_port(sap))
 347                 xprt_set_bound(xprt);
 348         xprt_rdma_format_addresses(xprt, sap);
 349
 350         new_xprt = rpcx_to_rdmax(xprt);
 351         rc = rpcrdma_ia_open(new_xprt);
 352         if (rc)
 353                 goto out1;
 354
 355         rc = rpcrdma_ep_create(new_xprt);
 356         if (rc)
 357                 goto out2;
 358
 359         rc = rpcrdma_buffer_create(new_xprt);
 360         if (rc)
 361                 goto out3;
 362
 363         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 364                           xprt_rdma_connect_worker);
 365
 366         xprt->max_payload = frwr_maxpages(new_xprt);
 367         if (xprt->max_payload == 0)
 368                 goto out4;
 369         xprt->max_payload <<= PAGE_SHIFT;
 370         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 371                 __func__, xprt->max_payload);
 372
 373         if (!try_module_get(THIS_MODULE))
 374                 goto out4;
 375
 376         dprintk("RPC:       %s: %s:%s\n", __func__,
 377                 xprt->address_strings[RPC_DISPLAY_ADDR],
 378                 xprt->address_strings[RPC_DISPLAY_PORT]);
 379         trace_xprtrdma_create(new_xprt);
 380         return xprt;
 381
 382 out4:
 383         rpcrdma_buffer_destroy(&new_xprt->rx_buf);
 384         rc = -ENODEV;
 385 out3:
 386         rpcrdma_ep_destroy(new_xprt);
 387 out2:
 388         rpcrdma_ia_close(&new_xprt->rx_ia);
 389 out1:
 390         trace_xprtrdma_op_destroy(new_xprt);
 391         xprt_rdma_free_addresses(xprt);
 392         xprt_free(xprt);
 393         return ERR_PTR(rc);
 394 }
 395
 396 /**
 397  * xprt_rdma_close - close a transport connection
 398  * @xprt: transport context
 399  *
 400  * Called during autoclose or device removal.
 401  *
 402  * Caller holds @xprt's send lock to prevent activity on this
 403  * transport while the connection is torn down.
 404  */
 405 void xprt_rdma_close(struct rpc_xprt *xprt)
 406 {
 407         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 408         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 409         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 410
 411         might_sleep();
 412
 413         trace_xprtrdma_op_close(r_xprt);
 414
 415         /* Prevent marshaling and sending of new requests */
 416         xprt_clear_connected(xprt);
 417
 418         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 419                 rpcrdma_ia_remove(ia);
 420                 goto out;
 421         }
 422
 423         if (ep->rep_connected == -ENODEV)
 424                 return;
 425         if (ep->rep_connected > 0)
 426                 xprt->reestablish_timeout = 0;
 427         rpcrdma_ep_disconnect(ep, ia);
 428
 429         /* Prepare @xprt for the next connection by reinitializing
 430          * its credit grant to one (see RFC 8166, Section 3.3.3).
 431          */
 432         r_xprt->rx_buf.rb_credits = 1;
 433         xprt->cwnd = RPC_CWNDSHIFT;
 434
 435 out:
 436         ++xprt->connect_cookie;
 437         xprt_disconnect_done(xprt);
 438 }
 439
 440 /**
 441  * xprt_rdma_set_port - update server port with rpcbind result
 442  * @xprt: controlling RPC transport
 443  * @port: new port value
 444  *
 445  * Transport connect status is unchanged.
 446  */
 447 static void
 448 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 449 {
 450         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 451         char buf[8];
 452
 453         dprintk("RPC:       %s: setting port for xprt %p (%s:%s) to %u\n",
 454                 __func__, xprt,
 455                 xprt->address_strings[RPC_DISPLAY_ADDR],
 456                 xprt->address_strings[RPC_DISPLAY_PORT],
 457                 port);
 458
 459         rpc_set_port(sap, port);
 460
 461         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 462         snprintf(buf, sizeof(buf), "%u", port);
 463         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 464
 465         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 466         snprintf(buf, sizeof(buf), "%4hx", port);
 467         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 468 }
 469
 470 /**
 471  * xprt_rdma_timer - invoked when an RPC times out
 472  * @xprt: controlling RPC transport
 473  * @task: RPC task that timed out
 474  *
 475  * Invoked when the transport is still connected, but an RPC
 476  * retransmit timeout occurs.
 477  *
 478  * Since RDMA connections don't have a keep-alive, forcibly
 479  * disconnect and retry to connect. This drives full
 480  * detection of the network path, and retransmissions of
 481  * all pending RPCs.
 482  */
 483 static void
 484 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 485 {
 486         xprt_force_disconnect(xprt);
 487 }
 488
 489 /**
 490  * xprt_rdma_connect - try to establish a transport connection
 491  * @xprt: transport state
 492  * @task: RPC scheduler context
 493  *
 494  */
 495 static void
 496 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 497 {
 498         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 499
 500         trace_xprtrdma_op_connect(r_xprt);
 501         if (r_xprt->rx_ep.rep_connected != 0) {
 502                 /* Reconnect */
 503                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 504                                       xprt->reestablish_timeout);
 505                 xprt->reestablish_timeout <<= 1;
 506                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 507                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 508                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 509                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 510         } else {
 511                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 512                 if (!RPC_IS_ASYNC(task))
 513                         flush_delayed_work(&r_xprt->rx_connect_worker);
 514         }
 515 }
 516
 517 /**
 518  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 519  * @xprt: controlling RPC transport
 520  * @task: RPC task requesting a fresh rpc_rqst
 521  *
 522  * tk_status values:
 523  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 524  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 525  */
 526 static void
 527 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 528 {
 529         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 530         struct rpcrdma_req *req;
 531
 532         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 533         if (!req)
 534                 goto out_sleep;
 535         task->tk_rqstp = &req->rl_slot;
 536         task->tk_status = 0;
 537         return;
 538
 539 out_sleep:
 540         rpc_sleep_on(&xprt->backlog, task, NULL);
 541         task->tk_status = -EAGAIN;
 542 }
 543
 544 /**
 545  * xprt_rdma_free_slot - release an rpc_rqst
 546  * @xprt: controlling RPC transport
 547  * @rqst: rpc_rqst to release
 548  *
 549  */
 550 static void
 551 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 552 {
 553         memset(rqst, 0, sizeof(*rqst));
 554         rpcrdma_buffer_put(rpcr_to_rdmar(rqst));
 555         rpc_wake_up_next(&xprt->backlog);
 556 }
 557
 558 static bool rpcrdma_check_regbuf(struct rpcrdma_xprt *r_xprt,
 559                                  struct rpcrdma_regbuf *rb, size_t size,
 560                                  gfp_t flags)
 561 {
 562         if (unlikely(rdmab_length(rb) < size)) {
 563                 if (!rpcrdma_regbuf_realloc(rb, size, flags))
 564                         return false;
 565                 r_xprt->rx_stats.hardway_register_count += size;
 566         }
 567         return true;
 568 }
 569
 570 /**
 571  * xprt_rdma_allocate - allocate transport resources for an RPC
 572  * @task: RPC task
 573  *
 574  * Return values:
 575  *        0:    Success; rq_buffer points to RPC buffer to use
 576  *   ENOMEM:    Out of memory, call again later
 577  *      EIO:    A permanent error occurred, do not retry
 578  */
 579 static int
 580 xprt_rdma_allocate(struct rpc_task *task)
 581 {
 582         struct rpc_rqst *rqst = task->tk_rqstp;
 583         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 584         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 585         gfp_t flags;
 586
 587         flags = RPCRDMA_DEF_GFP;
 588         if (RPC_IS_SWAPPER(task))
 589                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 590
 591         if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize,
 592                                   flags))
 593                 goto out_fail;
 594         if (!rpcrdma_check_regbuf(r_xprt, req->rl_recvbuf, rqst->rq_rcvsize,
 595                                   flags))
 596                 goto out_fail;
 597
 598         rqst->rq_buffer = rdmab_data(req->rl_sendbuf);
 599         rqst->rq_rbuffer = rdmab_data(req->rl_recvbuf);
 600         trace_xprtrdma_op_allocate(task, req);
 601         return 0;
 602
 603 out_fail:
 604         trace_xprtrdma_op_allocate(task, NULL);
 605         return -ENOMEM;
 606 }
 607
 608 /**
 609  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 610  * @task: RPC task
 611  *
 612  * Caller guarantees rqst->rq_buffer is non-NULL.
 613  */
 614 static void
 615 xprt_rdma_free(struct rpc_task *task)
 616 {
 617         struct rpc_rqst *rqst = task->tk_rqstp;
 618         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 619         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 620
 621         trace_xprtrdma_op_free(task, req);
 622
 623         if (!list_empty(&req->rl_registered))
 624                 frwr_unmap_sync(r_xprt, req);
 625
 626         /* XXX: If the RPC is completing because of a signal and
 627          * not because a reply was received, we ought to ensure
 628          * that the Send completion has fired, so that memory
 629          * involved with the Send is not still visible to the NIC.
 630          */
 631 }
 632
 633 /**
 634  * xprt_rdma_send_request - marshal and send an RPC request
 635  * @rqst: RPC message in rq_snd_buf
 636  *
 637  * Caller holds the transport's write lock.
 638  *
 639  * Returns:
 640  *      %0 if the RPC message has been sent
 641  *      %-ENOTCONN if the caller should reconnect and call again
 642  *      %-EAGAIN if the caller should call again
 643  *      %-ENOBUFS if the caller should call again after a delay
 644  *      %-EMSGSIZE if encoding ran out of buffer space. The request
 645  *              was not sent. Do not try to send this message again.
 646  *      %-EIO if an I/O error occurred. The request was not sent.
 647  *              Do not try to send this message again.
 648  */
 649 static int
 650 xprt_rdma_send_request(struct rpc_rqst *rqst)
 651 {
 652         struct rpc_xprt *xprt = rqst->rq_xprt;
 653         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 654         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 655         int rc = 0;
 656
 657 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 658         if (unlikely(!rqst->rq_buffer))
 659                 return xprt_rdma_bc_send_reply(rqst);
 660 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 661
 662         if (!xprt_connected(xprt))
 663                 return -ENOTCONN;
 664
 665         if (!xprt_request_get_cong(xprt, rqst))
 666                 return -EBADSLT;
 667
 668         rc = rpcrdma_marshal_req(r_xprt, rqst);
 669         if (rc < 0)
 670                 goto failed_marshal;
 671
 672         /* Must suppress retransmit to maintain credits */
 673         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 674                 goto drop_connection;
 675         rqst->rq_xtime = ktime_get();
 676
 677         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 678                 goto drop_connection;
 679
 680         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 681
 682         /* An RPC with no reply will throw off credit accounting,
 683          * so drop the connection to reset the credit grant.
 684          */
 685         if (!rpc_reply_expected(rqst->rq_task))
 686                 goto drop_connection;
 687         return 0;
 688
 689 failed_marshal:
 690         if (rc != -ENOTCONN)
 691                 return rc;
 692 drop_connection:
 693         xprt_rdma_close(xprt);
 694         return -ENOTCONN;
 695 }
 696
 697 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 698 {
 699         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 700         long idle_time = 0;
 701
 702         if (xprt_connected(xprt))
 703                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 704
 705         seq_puts(seq, "\txprt:\trdma ");
 706         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 707                    0,   /* need a local port? */
 708                    xprt->stat.bind_count,
 709                    xprt->stat.connect_count,
 710                    xprt->stat.connect_time / HZ,
 711                    idle_time,
 712                    xprt->stat.sends,
 713                    xprt->stat.recvs,
 714                    xprt->stat.bad_xids,
 715                    xprt->stat.req_u,
 716                    xprt->stat.bklog_u);
 717         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 718                    r_xprt->rx_stats.read_chunk_count,
 719                    r_xprt->rx_stats.write_chunk_count,
 720                    r_xprt->rx_stats.reply_chunk_count,
 721                    r_xprt->rx_stats.total_rdma_request,
 722                    r_xprt->rx_stats.total_rdma_reply,
 723                    r_xprt->rx_stats.pullup_copy_count,
 724                    r_xprt->rx_stats.fixup_copy_count,
 725                    r_xprt->rx_stats.hardway_register_count,
 726                    r_xprt->rx_stats.failed_marshal_count,
 727                    r_xprt->rx_stats.bad_reply_count,
 728                    r_xprt->rx_stats.nomsg_call_count);
 729         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 730                    r_xprt->rx_stats.mrs_recycled,
 731                    r_xprt->rx_stats.mrs_orphaned,
 732                    r_xprt->rx_stats.mrs_allocated,
 733                    r_xprt->rx_stats.local_inv_needed,
 734                    r_xprt->rx_stats.empty_sendctx_q,
 735                    r_xprt->rx_stats.reply_waits_for_send);
 736 }
 737
 738 static int
 739 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 740 {
 741         return 0;
 742 }
 743
 744 static void
 745 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 746 {
 747 }
 748
 749 /*
 750  * Plumbing for rpc transport switch and kernel module
 751  */
 752
 753 static const struct rpc_xprt_ops xprt_rdma_procs = {
 754         .reserve_xprt           = xprt_reserve_xprt_cong,
 755         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 756         .alloc_slot             = xprt_rdma_alloc_slot,
 757         .free_slot              = xprt_rdma_free_slot,
 758         .release_request        = xprt_release_rqst_cong,       /* ditto */
 759         .wait_for_reply_request = xprt_wait_for_reply_request_def, /* ditto */
 760         .timer                  = xprt_rdma_timer,
 761         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 762         .set_port               = xprt_rdma_set_port,
 763         .connect                = xprt_rdma_connect,
 764         .buf_alloc              = xprt_rdma_allocate,
 765         .buf_free               = xprt_rdma_free,
 766         .send_request           = xprt_rdma_send_request,
 767         .close                  = xprt_rdma_close,
 768         .destroy                = xprt_rdma_destroy,
 769         .print_stats            = xprt_rdma_print_stats,
 770         .enable_swap            = xprt_rdma_enable_swap,
 771         .disable_swap           = xprt_rdma_disable_swap,
 772         .inject_disconnect      = xprt_rdma_inject_disconnect,
 773 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 774         .bc_setup               = xprt_rdma_bc_setup,
 775         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 776         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 777         .bc_destroy             = xprt_rdma_bc_destroy,
 778 #endif
 779 };
 780
 781 static struct xprt_class xprt_rdma = {
 782         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 783         .name                   = "rdma",
 784         .owner                  = THIS_MODULE,
 785         .ident                  = XPRT_TRANSPORT_RDMA,
 786         .setup                  = xprt_setup_rdma,
 787 };
 788
 789 void xprt_rdma_cleanup(void)
 790 {
 791 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 792         if (sunrpc_table_header) {
 793                 unregister_sysctl_table(sunrpc_table_header);
 794                 sunrpc_table_header = NULL;
 795         }
 796 #endif
 797
 798         xprt_unregister_transport(&xprt_rdma);
 799         xprt_unregister_transport(&xprt_rdma_bc);
 800 }
 801
 802 int xprt_rdma_init(void)
 803 {
 804         int rc;
 805
 806         rc = xprt_register_transport(&xprt_rdma);
 807         if (rc)
 808                 return rc;
 809
 810         rc = xprt_register_transport(&xprt_rdma_bc);
 811         if (rc) {
 812                 xprt_unregister_transport(&xprt_rdma);
 813                 return rc;
 814         }
 815
 816 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 817         if (!sunrpc_table_header)
 818                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 819 #endif
 820         return 0;
 821 }