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 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 static struct xprt_class xprt_rdma;
  77
  78 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  79
  80 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  81 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  82 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  83 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  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         = SYSCTL_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_xprt_connect(r_xprt);
 245         xprt_clear_connecting(xprt);
 246         if (!rc) {
 247                 xprt->connect_cookie++;
 248                 xprt->stat.connect_count++;
 249                 xprt->stat.connect_time += (long)jiffies -
 250                                            xprt->stat.connect_start;
 251                 xprt_set_connected(xprt);
 252                 rc = -EAGAIN;
 253         } else {
 254                 /* Force a call to xprt_rdma_close to clean up */
 255                 spin_lock(&xprt->transport_lock);
 256                 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 257                 spin_unlock(&xprt->transport_lock);
 258         }
 259         xprt_wake_pending_tasks(xprt, rc);
 260 }
 261
 262 /**
 263  * xprt_rdma_inject_disconnect - inject a connection fault
 264  * @xprt: transport context
 265  *
 266  * If @xprt is connected, disconnect it to simulate spurious
 267  * connection loss. Caller must hold @xprt's send lock to
 268  * ensure that data structures and hardware resources are
 269  * stable during the rdma_disconnect() call.
 270  */
 271 static void
 272 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 273 {
 274         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 275
 276         trace_xprtrdma_op_inject_dsc(r_xprt);
 277         rdma_disconnect(r_xprt->rx_ep->re_id);
 278 }
 279
 280 /**
 281  * xprt_rdma_destroy - Full tear down of transport
 282  * @xprt: doomed transport context
 283  *
 284  * Caller guarantees there will be no more calls to us with
 285  * this @xprt.
 286  */
 287 static void
 288 xprt_rdma_destroy(struct rpc_xprt *xprt)
 289 {
 290         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 291
 292         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 293
 294         rpcrdma_xprt_disconnect(r_xprt);
 295         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 296
 297         xprt_rdma_free_addresses(xprt);
 298         xprt_free(xprt);
 299
 300         module_put(THIS_MODULE);
 301 }
 302
 303 /* 60 second timeout, no retries */
 304 static const struct rpc_timeout xprt_rdma_default_timeout = {
 305         .to_initval = 60 * HZ,
 306         .to_maxval = 60 * HZ,
 307 };
 308
 309 /**
 310  * xprt_setup_rdma - Set up transport to use RDMA
 311  *
 312  * @args: rpc transport arguments
 313  */
 314 static struct rpc_xprt *
 315 xprt_setup_rdma(struct xprt_create *args)
 316 {
 317         struct rpc_xprt *xprt;
 318         struct rpcrdma_xprt *new_xprt;
 319         struct sockaddr *sap;
 320         int rc;
 321
 322         if (args->addrlen > sizeof(xprt->addr))
 323                 return ERR_PTR(-EBADF);
 324
 325         if (!try_module_get(THIS_MODULE))
 326                 return ERR_PTR(-EIO);
 327
 328         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0,
 329                           xprt_rdma_slot_table_entries);
 330         if (!xprt) {
 331                 module_put(THIS_MODULE);
 332                 return ERR_PTR(-ENOMEM);
 333         }
 334
 335         xprt->timeout = &xprt_rdma_default_timeout;
 336         xprt->connect_timeout = xprt->timeout->to_initval;
 337         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
 338         xprt->bind_timeout = RPCRDMA_BIND_TO;
 339         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 340         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 341
 342         xprt->resvport = 0;             /* privileged port not needed */
 343         xprt->ops = &xprt_rdma_procs;
 344
 345         /*
 346          * Set up RDMA-specific connect data.
 347          */
 348         sap = args->dstaddr;
 349
 350         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 351          * address, for any side protocols which peek at it */
 352         xprt->prot = IPPROTO_TCP;
 353         xprt->xprt_class = &xprt_rdma;
 354         xprt->addrlen = args->addrlen;
 355         memcpy(&xprt->addr, sap, xprt->addrlen);
 356
 357         if (rpc_get_port(sap))
 358                 xprt_set_bound(xprt);
 359         xprt_rdma_format_addresses(xprt, sap);
 360
 361         new_xprt = rpcx_to_rdmax(xprt);
 362         rc = rpcrdma_buffer_create(new_xprt);
 363         if (rc) {
 364                 xprt_rdma_free_addresses(xprt);
 365                 xprt_free(xprt);
 366                 module_put(THIS_MODULE);
 367                 return ERR_PTR(rc);
 368         }
 369
 370         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 371                           xprt_rdma_connect_worker);
 372
 373         xprt->max_payload = RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT;
 374
 375         return xprt;
 376 }
 377
 378 /**
 379  * xprt_rdma_close - close a transport connection
 380  * @xprt: transport context
 381  *
 382  * Called during autoclose or device removal.
 383  *
 384  * Caller holds @xprt's send lock to prevent activity on this
 385  * transport while the connection is torn down.
 386  */
 387 void xprt_rdma_close(struct rpc_xprt *xprt)
 388 {
 389         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 390
 391         rpcrdma_xprt_disconnect(r_xprt);
 392
 393         xprt->reestablish_timeout = 0;
 394         ++xprt->connect_cookie;
 395         xprt_disconnect_done(xprt);
 396 }
 397
 398 /**
 399  * xprt_rdma_set_port - update server port with rpcbind result
 400  * @xprt: controlling RPC transport
 401  * @port: new port value
 402  *
 403  * Transport connect status is unchanged.
 404  */
 405 static void
 406 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 407 {
 408         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 409         char buf[8];
 410
 411         rpc_set_port(sap, port);
 412
 413         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 414         snprintf(buf, sizeof(buf), "%u", port);
 415         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 416
 417         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 418         snprintf(buf, sizeof(buf), "%4hx", port);
 419         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 420 }
 421
 422 /**
 423  * xprt_rdma_timer - invoked when an RPC times out
 424  * @xprt: controlling RPC transport
 425  * @task: RPC task that timed out
 426  *
 427  * Invoked when the transport is still connected, but an RPC
 428  * retransmit timeout occurs.
 429  *
 430  * Since RDMA connections don't have a keep-alive, forcibly
 431  * disconnect and retry to connect. This drives full
 432  * detection of the network path, and retransmissions of
 433  * all pending RPCs.
 434  */
 435 static void
 436 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 437 {
 438         xprt_force_disconnect(xprt);
 439 }
 440
 441 /**
 442  * xprt_rdma_set_connect_timeout - set timeouts for establishing a connection
 443  * @xprt: controlling transport instance
 444  * @connect_timeout: reconnect timeout after client disconnects
 445  * @reconnect_timeout: reconnect timeout after server disconnects
 446  *
 447  */
 448 static void xprt_rdma_set_connect_timeout(struct rpc_xprt *xprt,
 449                                           unsigned long connect_timeout,
 450                                           unsigned long reconnect_timeout)
 451 {
 452         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 453
 454         trace_xprtrdma_op_set_cto(r_xprt, connect_timeout, reconnect_timeout);
 455
 456         spin_lock(&xprt->transport_lock);
 457
 458         if (connect_timeout < xprt->connect_timeout) {
 459                 struct rpc_timeout to;
 460                 unsigned long initval;
 461
 462                 to = *xprt->timeout;
 463                 initval = connect_timeout;
 464                 if (initval < RPCRDMA_INIT_REEST_TO << 1)
 465                         initval = RPCRDMA_INIT_REEST_TO << 1;
 466                 to.to_initval = initval;
 467                 to.to_maxval = initval;
 468                 r_xprt->rx_timeout = to;
 469                 xprt->timeout = &r_xprt->rx_timeout;
 470                 xprt->connect_timeout = connect_timeout;
 471         }
 472
 473         if (reconnect_timeout < xprt->max_reconnect_timeout)
 474                 xprt->max_reconnect_timeout = reconnect_timeout;
 475
 476         spin_unlock(&xprt->transport_lock);
 477 }
 478
 479 /**
 480  * xprt_rdma_connect - schedule an attempt to reconnect
 481  * @xprt: transport state
 482  * @task: RPC scheduler context (unused)
 483  *
 484  */
 485 static void
 486 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 487 {
 488         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 489         struct rpcrdma_ep *ep = r_xprt->rx_ep;
 490         unsigned long delay;
 491
 492         delay = 0;
 493         if (ep && ep->re_connect_status != 0) {
 494                 delay = xprt_reconnect_delay(xprt);
 495                 xprt_reconnect_backoff(xprt, RPCRDMA_INIT_REEST_TO);
 496         }
 497         trace_xprtrdma_op_connect(r_xprt, delay);
 498         queue_delayed_work(xprtiod_workqueue, &r_xprt->rx_connect_worker,
 499                            delay);
 500 }
 501
 502 /**
 503  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 504  * @xprt: controlling RPC transport
 505  * @task: RPC task requesting a fresh rpc_rqst
 506  *
 507  * tk_status values:
 508  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 509  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 510  */
 511 static void
 512 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 513 {
 514         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 515         struct rpcrdma_req *req;
 516
 517         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 518         if (!req)
 519                 goto out_sleep;
 520         task->tk_rqstp = &req->rl_slot;
 521         task->tk_status = 0;
 522         return;
 523
 524 out_sleep:
 525         task->tk_status = -EAGAIN;
 526         xprt_add_backlog(xprt, task);
 527 }
 528
 529 /**
 530  * xprt_rdma_free_slot - release an rpc_rqst
 531  * @xprt: controlling RPC transport
 532  * @rqst: rpc_rqst to release
 533  *
 534  */
 535 static void
 536 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 537 {
 538         struct rpcrdma_xprt *r_xprt =
 539                 container_of(xprt, struct rpcrdma_xprt, rx_xprt);
 540
 541         rpcrdma_reply_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst));
 542         if (!xprt_wake_up_backlog(xprt, rqst)) {
 543                 memset(rqst, 0, sizeof(*rqst));
 544                 rpcrdma_buffer_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst));
 545         }
 546 }
 547
 548 static bool rpcrdma_check_regbuf(struct rpcrdma_xprt *r_xprt,
 549                                  struct rpcrdma_regbuf *rb, size_t size,
 550                                  gfp_t flags)
 551 {
 552         if (unlikely(rdmab_length(rb) < size)) {
 553                 if (!rpcrdma_regbuf_realloc(rb, size, flags))
 554                         return false;
 555                 r_xprt->rx_stats.hardway_register_count += size;
 556         }
 557         return true;
 558 }
 559
 560 /**
 561  * xprt_rdma_allocate - allocate transport resources for an RPC
 562  * @task: RPC task
 563  *
 564  * Return values:
 565  *        0:    Success; rq_buffer points to RPC buffer to use
 566  *   ENOMEM:    Out of memory, call again later
 567  *      EIO:    A permanent error occurred, do not retry
 568  */
 569 static int
 570 xprt_rdma_allocate(struct rpc_task *task)
 571 {
 572         struct rpc_rqst *rqst = task->tk_rqstp;
 573         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 574         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 575         gfp_t flags;
 576
 577         flags = RPCRDMA_DEF_GFP;
 578         if (RPC_IS_SWAPPER(task))
 579                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 580
 581         if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize,
 582                                   flags))
 583                 goto out_fail;
 584         if (!rpcrdma_check_regbuf(r_xprt, req->rl_recvbuf, rqst->rq_rcvsize,
 585                                   flags))
 586                 goto out_fail;
 587
 588         rqst->rq_buffer = rdmab_data(req->rl_sendbuf);
 589         rqst->rq_rbuffer = rdmab_data(req->rl_recvbuf);
 590         return 0;
 591
 592 out_fail:
 593         return -ENOMEM;
 594 }
 595
 596 /**
 597  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 598  * @task: RPC task
 599  *
 600  * Caller guarantees rqst->rq_buffer is non-NULL.
 601  */
 602 static void
 603 xprt_rdma_free(struct rpc_task *task)
 604 {
 605         struct rpc_rqst *rqst = task->tk_rqstp;
 606         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 607
 608         if (unlikely(!list_empty(&req->rl_registered))) {
 609                 trace_xprtrdma_mrs_zap(task);
 610                 frwr_unmap_sync(rpcx_to_rdmax(rqst->rq_xprt), req);
 611         }
 612
 613         /* XXX: If the RPC is completing because of a signal and
 614          * not because a reply was received, we ought to ensure
 615          * that the Send completion has fired, so that memory
 616          * involved with the Send is not still visible to the NIC.
 617          */
 618 }
 619
 620 /**
 621  * xprt_rdma_send_request - marshal and send an RPC request
 622  * @rqst: RPC message in rq_snd_buf
 623  *
 624  * Caller holds the transport's write lock.
 625  *
 626  * Returns:
 627  *      %0 if the RPC message has been sent
 628  *      %-ENOTCONN if the caller should reconnect and call again
 629  *      %-EAGAIN if the caller should call again
 630  *      %-ENOBUFS if the caller should call again after a delay
 631  *      %-EMSGSIZE if encoding ran out of buffer space. The request
 632  *              was not sent. Do not try to send this message again.
 633  *      %-EIO if an I/O error occurred. The request was not sent.
 634  *              Do not try to send this message again.
 635  */
 636 static int
 637 xprt_rdma_send_request(struct rpc_rqst *rqst)
 638 {
 639         struct rpc_xprt *xprt = rqst->rq_xprt;
 640         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 641         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 642         int rc = 0;
 643
 644 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 645         if (unlikely(!rqst->rq_buffer))
 646                 return xprt_rdma_bc_send_reply(rqst);
 647 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 648
 649         if (!xprt_connected(xprt))
 650                 return -ENOTCONN;
 651
 652         if (!xprt_request_get_cong(xprt, rqst))
 653                 return -EBADSLT;
 654
 655         rc = rpcrdma_marshal_req(r_xprt, rqst);
 656         if (rc < 0)
 657                 goto failed_marshal;
 658
 659         /* Must suppress retransmit to maintain credits */
 660         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 661                 goto drop_connection;
 662         rqst->rq_xtime = ktime_get();
 663
 664         if (rpcrdma_post_sends(r_xprt, req))
 665                 goto drop_connection;
 666
 667         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 668
 669         /* An RPC with no reply will throw off credit accounting,
 670          * so drop the connection to reset the credit grant.
 671          */
 672         if (!rpc_reply_expected(rqst->rq_task))
 673                 goto drop_connection;
 674         return 0;
 675
 676 failed_marshal:
 677         if (rc != -ENOTCONN)
 678                 return rc;
 679 drop_connection:
 680         xprt_rdma_close(xprt);
 681         return -ENOTCONN;
 682 }
 683
 684 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 685 {
 686         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 687         long idle_time = 0;
 688
 689         if (xprt_connected(xprt))
 690                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 691
 692         seq_puts(seq, "\txprt:\trdma ");
 693         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 694                    0,   /* need a local port? */
 695                    xprt->stat.bind_count,
 696                    xprt->stat.connect_count,
 697                    xprt->stat.connect_time / HZ,
 698                    idle_time,
 699                    xprt->stat.sends,
 700                    xprt->stat.recvs,
 701                    xprt->stat.bad_xids,
 702                    xprt->stat.req_u,
 703                    xprt->stat.bklog_u);
 704         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 705                    r_xprt->rx_stats.read_chunk_count,
 706                    r_xprt->rx_stats.write_chunk_count,
 707                    r_xprt->rx_stats.reply_chunk_count,
 708                    r_xprt->rx_stats.total_rdma_request,
 709                    r_xprt->rx_stats.total_rdma_reply,
 710                    r_xprt->rx_stats.pullup_copy_count,
 711                    r_xprt->rx_stats.fixup_copy_count,
 712                    r_xprt->rx_stats.hardway_register_count,
 713                    r_xprt->rx_stats.failed_marshal_count,
 714                    r_xprt->rx_stats.bad_reply_count,
 715                    r_xprt->rx_stats.nomsg_call_count);
 716         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 717                    r_xprt->rx_stats.mrs_recycled,
 718                    r_xprt->rx_stats.mrs_orphaned,
 719                    r_xprt->rx_stats.mrs_allocated,
 720                    r_xprt->rx_stats.local_inv_needed,
 721                    r_xprt->rx_stats.empty_sendctx_q,
 722                    r_xprt->rx_stats.reply_waits_for_send);
 723 }
 724
 725 static int
 726 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 727 {
 728         return 0;
 729 }
 730
 731 static void
 732 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 733 {
 734 }
 735
 736 /*
 737  * Plumbing for rpc transport switch and kernel module
 738  */
 739
 740 static const struct rpc_xprt_ops xprt_rdma_procs = {
 741         .reserve_xprt           = xprt_reserve_xprt_cong,
 742         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 743         .alloc_slot             = xprt_rdma_alloc_slot,
 744         .free_slot              = xprt_rdma_free_slot,
 745         .release_request        = xprt_release_rqst_cong,       /* ditto */
 746         .wait_for_reply_request = xprt_wait_for_reply_request_def, /* ditto */
 747         .timer                  = xprt_rdma_timer,
 748         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 749         .set_port               = xprt_rdma_set_port,
 750         .connect                = xprt_rdma_connect,
 751         .buf_alloc              = xprt_rdma_allocate,
 752         .buf_free               = xprt_rdma_free,
 753         .send_request           = xprt_rdma_send_request,
 754         .close                  = xprt_rdma_close,
 755         .destroy                = xprt_rdma_destroy,
 756         .set_connect_timeout    = xprt_rdma_set_connect_timeout,
 757         .print_stats            = xprt_rdma_print_stats,
 758         .enable_swap            = xprt_rdma_enable_swap,
 759         .disable_swap           = xprt_rdma_disable_swap,
 760         .inject_disconnect      = xprt_rdma_inject_disconnect,
 761 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 762         .bc_setup               = xprt_rdma_bc_setup,
 763         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 764         .bc_num_slots           = xprt_rdma_bc_max_slots,
 765         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 766         .bc_destroy             = xprt_rdma_bc_destroy,
 767 #endif
 768 };
 769
 770 static struct xprt_class xprt_rdma = {
 771         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 772         .name                   = "rdma",
 773         .owner                  = THIS_MODULE,
 774         .ident                  = XPRT_TRANSPORT_RDMA,
 775         .setup                  = xprt_setup_rdma,
 776         .netid                  = { "rdma", "rdma6", "" },
 777 };
 778
 779 void xprt_rdma_cleanup(void)
 780 {
 781 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 782         if (sunrpc_table_header) {
 783                 unregister_sysctl_table(sunrpc_table_header);
 784                 sunrpc_table_header = NULL;
 785         }
 786 #endif
 787
 788         xprt_unregister_transport(&xprt_rdma);
 789         xprt_unregister_transport(&xprt_rdma_bc);
 790 }
 791
 792 int xprt_rdma_init(void)
 793 {
 794         int rc;
 795
 796         rc = xprt_register_transport(&xprt_rdma);
 797         if (rc)
 798                 return rc;
 799
 800         rc = xprt_register_transport(&xprt_rdma_bc);
 801         if (rc) {
 802                 xprt_unregister_transport(&xprt_rdma);
 803                 return rc;
 804         }
 805
 806 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 807         if (!sunrpc_table_header)
 808                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 809 #endif
 810         return 0;
 811 }