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 /*
  64  * tunables
  65  */
  66
  67 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  68 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  69 unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  70 unsigned int xprt_rdma_memreg_strategy          = RPCRDMA_FRWR;
  71 int xprt_rdma_pad_optimize;
  72 static struct xprt_class xprt_rdma;
  73
  74 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  75
  76 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  77 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  78 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  79 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  80 static unsigned int max_padding = PAGE_SIZE;
  81 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  82 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  83 static unsigned int dummy;
  84
  85 static struct ctl_table_header *sunrpc_table_header;
  86
  87 static struct ctl_table xr_tunables_table[] = {
  88         {
  89                 .procname       = "rdma_slot_table_entries",
  90                 .data           = &xprt_rdma_slot_table_entries,
  91                 .maxlen         = sizeof(unsigned int),
  92                 .mode           = 0644,
  93                 .proc_handler   = proc_dointvec_minmax,
  94                 .extra1         = &min_slot_table_size,
  95                 .extra2         = &max_slot_table_size
  96         },
  97         {
  98                 .procname       = "rdma_max_inline_read",
  99                 .data           = &xprt_rdma_max_inline_read,
 100                 .maxlen         = sizeof(unsigned int),
 101                 .mode           = 0644,
 102                 .proc_handler   = proc_dointvec_minmax,
 103                 .extra1         = &min_inline_size,
 104                 .extra2         = &max_inline_size,
 105         },
 106         {
 107                 .procname       = "rdma_max_inline_write",
 108                 .data           = &xprt_rdma_max_inline_write,
 109                 .maxlen         = sizeof(unsigned int),
 110                 .mode           = 0644,
 111                 .proc_handler   = proc_dointvec_minmax,
 112                 .extra1         = &min_inline_size,
 113                 .extra2         = &max_inline_size,
 114         },
 115         {
 116                 .procname       = "rdma_inline_write_padding",
 117                 .data           = &dummy,
 118                 .maxlen         = sizeof(unsigned int),
 119                 .mode           = 0644,
 120                 .proc_handler   = proc_dointvec_minmax,
 121                 .extra1         = SYSCTL_ZERO,
 122                 .extra2         = &max_padding,
 123         },
 124         {
 125                 .procname       = "rdma_memreg_strategy",
 126                 .data           = &xprt_rdma_memreg_strategy,
 127                 .maxlen         = sizeof(unsigned int),
 128                 .mode           = 0644,
 129                 .proc_handler   = proc_dointvec_minmax,
 130                 .extra1         = &min_memreg,
 131                 .extra2         = &max_memreg,
 132         },
 133         {
 134                 .procname       = "rdma_pad_optimize",
 135                 .data           = &xprt_rdma_pad_optimize,
 136                 .maxlen         = sizeof(unsigned int),
 137                 .mode           = 0644,
 138                 .proc_handler   = proc_dointvec,
 139         },
 140         { },
 141 };
 142
 143 #endif
 144
 145 static const struct rpc_xprt_ops xprt_rdma_procs;
 146
 147 static void
 148 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 149 {
 150         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 151         char buf[20];
 152
 153         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 154         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 155
 156         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 157 }
 158
 159 static void
 160 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 161 {
 162         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 163         char buf[40];
 164
 165         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 166         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 167
 168         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 169 }
 170
 171 void
 172 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 173 {
 174         char buf[128];
 175
 176         switch (sap->sa_family) {
 177         case AF_INET:
 178                 xprt_rdma_format_addresses4(xprt, sap);
 179                 break;
 180         case AF_INET6:
 181                 xprt_rdma_format_addresses6(xprt, sap);
 182                 break;
 183         default:
 184                 pr_err("rpcrdma: Unrecognized address family\n");
 185                 return;
 186         }
 187
 188         (void)rpc_ntop(sap, buf, sizeof(buf));
 189         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 190
 191         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 192         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 193
 194         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 195         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 196
 197         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 198 }
 199
 200 void
 201 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 202 {
 203         unsigned int i;
 204
 205         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 206                 switch (i) {
 207                 case RPC_DISPLAY_PROTO:
 208                 case RPC_DISPLAY_NETID:
 209                         continue;
 210                 default:
 211                         kfree(xprt->address_strings[i]);
 212                 }
 213 }
 214
 215 /**
 216  * xprt_rdma_connect_worker - establish connection in the background
 217  * @work: worker thread context
 218  *
 219  * Requester holds the xprt's send lock to prevent activity on this
 220  * transport while a fresh connection is being established. RPC tasks
 221  * sleep on the xprt's pending queue waiting for connect to complete.
 222  */
 223 static void
 224 xprt_rdma_connect_worker(struct work_struct *work)
 225 {
 226         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 227                                                    rx_connect_worker.work);
 228         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 229         unsigned int pflags = current->flags;
 230         int rc;
 231
 232         if (atomic_read(&xprt->swapper))
 233                 current->flags |= PF_MEMALLOC;
 234         rc = rpcrdma_xprt_connect(r_xprt);
 235         xprt_clear_connecting(xprt);
 236         if (!rc) {
 237                 xprt->connect_cookie++;
 238                 xprt->stat.connect_count++;
 239                 xprt->stat.connect_time += (long)jiffies -
 240                                            xprt->stat.connect_start;
 241                 xprt_set_connected(xprt);
 242                 rc = -EAGAIN;
 243         } else
 244                 rpcrdma_xprt_disconnect(r_xprt);
 245         xprt_unlock_connect(xprt, r_xprt);
 246         xprt_wake_pending_tasks(xprt, rc);
 247         current_restore_flags(pflags, PF_MEMALLOC);
 248 }
 249
 250 /**
 251  * xprt_rdma_inject_disconnect - inject a connection fault
 252  * @xprt: transport context
 253  *
 254  * If @xprt is connected, disconnect it to simulate spurious
 255  * connection loss. Caller must hold @xprt's send lock to
 256  * ensure that data structures and hardware resources are
 257  * stable during the rdma_disconnect() call.
 258  */
 259 static void
 260 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 261 {
 262         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 263
 264         trace_xprtrdma_op_inject_dsc(r_xprt);
 265         rdma_disconnect(r_xprt->rx_ep->re_id);
 266 }
 267
 268 /**
 269  * xprt_rdma_destroy - Full tear down of transport
 270  * @xprt: doomed transport context
 271  *
 272  * Caller guarantees there will be no more calls to us with
 273  * this @xprt.
 274  */
 275 static void
 276 xprt_rdma_destroy(struct rpc_xprt *xprt)
 277 {
 278         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 279
 280         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 281
 282         rpcrdma_xprt_disconnect(r_xprt);
 283         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 284
 285         xprt_rdma_free_addresses(xprt);
 286         xprt_free(xprt);
 287
 288         module_put(THIS_MODULE);
 289 }
 290
 291 /* 60 second timeout, no retries */
 292 static const struct rpc_timeout xprt_rdma_default_timeout = {
 293         .to_initval = 60 * HZ,
 294         .to_maxval = 60 * HZ,
 295 };
 296
 297 /**
 298  * xprt_setup_rdma - Set up transport to use RDMA
 299  *
 300  * @args: rpc transport arguments
 301  */
 302 static struct rpc_xprt *
 303 xprt_setup_rdma(struct xprt_create *args)
 304 {
 305         struct rpc_xprt *xprt;
 306         struct rpcrdma_xprt *new_xprt;
 307         struct sockaddr *sap;
 308         int rc;
 309
 310         if (args->addrlen > sizeof(xprt->addr))
 311                 return ERR_PTR(-EBADF);
 312
 313         if (!try_module_get(THIS_MODULE))
 314                 return ERR_PTR(-EIO);
 315
 316         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0,
 317                           xprt_rdma_slot_table_entries);
 318         if (!xprt) {
 319                 module_put(THIS_MODULE);
 320                 return ERR_PTR(-ENOMEM);
 321         }
 322
 323         xprt->timeout = &xprt_rdma_default_timeout;
 324         xprt->connect_timeout = xprt->timeout->to_initval;
 325         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
 326         xprt->bind_timeout = RPCRDMA_BIND_TO;
 327         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 328         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 329
 330         xprt->resvport = 0;             /* privileged port not needed */
 331         xprt->ops = &xprt_rdma_procs;
 332
 333         /*
 334          * Set up RDMA-specific connect data.
 335          */
 336         sap = args->dstaddr;
 337
 338         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 339          * address, for any side protocols which peek at it */
 340         xprt->prot = IPPROTO_TCP;
 341         xprt->xprt_class = &xprt_rdma;
 342         xprt->addrlen = args->addrlen;
 343         memcpy(&xprt->addr, sap, xprt->addrlen);
 344
 345         if (rpc_get_port(sap))
 346                 xprt_set_bound(xprt);
 347         xprt_rdma_format_addresses(xprt, sap);
 348
 349         new_xprt = rpcx_to_rdmax(xprt);
 350         rc = rpcrdma_buffer_create(new_xprt);
 351         if (rc) {
 352                 xprt_rdma_free_addresses(xprt);
 353                 xprt_free(xprt);
 354                 module_put(THIS_MODULE);
 355                 return ERR_PTR(rc);
 356         }
 357
 358         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 359                           xprt_rdma_connect_worker);
 360
 361         xprt->max_payload = RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT;
 362
 363         return xprt;
 364 }
 365
 366 /**
 367  * xprt_rdma_close - close a transport connection
 368  * @xprt: transport context
 369  *
 370  * Called during autoclose or device removal.
 371  *
 372  * Caller holds @xprt's send lock to prevent activity on this
 373  * transport while the connection is torn down.
 374  */
 375 void xprt_rdma_close(struct rpc_xprt *xprt)
 376 {
 377         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 378
 379         rpcrdma_xprt_disconnect(r_xprt);
 380
 381         xprt->reestablish_timeout = 0;
 382         ++xprt->connect_cookie;
 383         xprt_disconnect_done(xprt);
 384 }
 385
 386 /**
 387  * xprt_rdma_set_port - update server port with rpcbind result
 388  * @xprt: controlling RPC transport
 389  * @port: new port value
 390  *
 391  * Transport connect status is unchanged.
 392  */
 393 static void
 394 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 395 {
 396         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 397         char buf[8];
 398
 399         rpc_set_port(sap, port);
 400
 401         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 402         snprintf(buf, sizeof(buf), "%u", port);
 403         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 404
 405         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 406         snprintf(buf, sizeof(buf), "%4hx", port);
 407         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 408 }
 409
 410 /**
 411  * xprt_rdma_timer - invoked when an RPC times out
 412  * @xprt: controlling RPC transport
 413  * @task: RPC task that timed out
 414  *
 415  * Invoked when the transport is still connected, but an RPC
 416  * retransmit timeout occurs.
 417  *
 418  * Since RDMA connections don't have a keep-alive, forcibly
 419  * disconnect and retry to connect. This drives full
 420  * detection of the network path, and retransmissions of
 421  * all pending RPCs.
 422  */
 423 static void
 424 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 425 {
 426         xprt_force_disconnect(xprt);
 427 }
 428
 429 /**
 430  * xprt_rdma_set_connect_timeout - set timeouts for establishing a connection
 431  * @xprt: controlling transport instance
 432  * @connect_timeout: reconnect timeout after client disconnects
 433  * @reconnect_timeout: reconnect timeout after server disconnects
 434  *
 435  */
 436 static void xprt_rdma_set_connect_timeout(struct rpc_xprt *xprt,
 437                                           unsigned long connect_timeout,
 438                                           unsigned long reconnect_timeout)
 439 {
 440         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 441
 442         trace_xprtrdma_op_set_cto(r_xprt, connect_timeout, reconnect_timeout);
 443
 444         spin_lock(&xprt->transport_lock);
 445
 446         if (connect_timeout < xprt->connect_timeout) {
 447                 struct rpc_timeout to;
 448                 unsigned long initval;
 449
 450                 to = *xprt->timeout;
 451                 initval = connect_timeout;
 452                 if (initval < RPCRDMA_INIT_REEST_TO << 1)
 453                         initval = RPCRDMA_INIT_REEST_TO << 1;
 454                 to.to_initval = initval;
 455                 to.to_maxval = initval;
 456                 r_xprt->rx_timeout = to;
 457                 xprt->timeout = &r_xprt->rx_timeout;
 458                 xprt->connect_timeout = connect_timeout;
 459         }
 460
 461         if (reconnect_timeout < xprt->max_reconnect_timeout)
 462                 xprt->max_reconnect_timeout = reconnect_timeout;
 463
 464         spin_unlock(&xprt->transport_lock);
 465 }
 466
 467 /**
 468  * xprt_rdma_connect - schedule an attempt to reconnect
 469  * @xprt: transport state
 470  * @task: RPC scheduler context (unused)
 471  *
 472  */
 473 static void
 474 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 475 {
 476         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 477         struct rpcrdma_ep *ep = r_xprt->rx_ep;
 478         unsigned long delay;
 479
 480         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, r_xprt));
 481
 482         delay = 0;
 483         if (ep && ep->re_connect_status != 0) {
 484                 delay = xprt_reconnect_delay(xprt);
 485                 xprt_reconnect_backoff(xprt, RPCRDMA_INIT_REEST_TO);
 486         }
 487         trace_xprtrdma_op_connect(r_xprt, delay);
 488         queue_delayed_work(system_long_wq, &r_xprt->rx_connect_worker, delay);
 489 }
 490
 491 /**
 492  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 493  * @xprt: controlling RPC transport
 494  * @task: RPC task requesting a fresh rpc_rqst
 495  *
 496  * tk_status values:
 497  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 498  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 499  */
 500 static void
 501 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 502 {
 503         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 504         struct rpcrdma_req *req;
 505
 506         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 507         if (!req)
 508                 goto out_sleep;
 509         task->tk_rqstp = &req->rl_slot;
 510         task->tk_status = 0;
 511         return;
 512
 513 out_sleep:
 514         task->tk_status = -ENOMEM;
 515         xprt_add_backlog(xprt, task);
 516 }
 517
 518 /**
 519  * xprt_rdma_free_slot - release an rpc_rqst
 520  * @xprt: controlling RPC transport
 521  * @rqst: rpc_rqst to release
 522  *
 523  */
 524 static void
 525 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 526 {
 527         struct rpcrdma_xprt *r_xprt =
 528                 container_of(xprt, struct rpcrdma_xprt, rx_xprt);
 529
 530         rpcrdma_reply_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst));
 531         if (!xprt_wake_up_backlog(xprt, rqst)) {
 532                 memset(rqst, 0, sizeof(*rqst));
 533                 rpcrdma_buffer_put(&r_xprt->rx_buf, rpcr_to_rdmar(rqst));
 534         }
 535 }
 536
 537 static bool rpcrdma_check_regbuf(struct rpcrdma_xprt *r_xprt,
 538                                  struct rpcrdma_regbuf *rb, size_t size,
 539                                  gfp_t flags)
 540 {
 541         if (unlikely(rdmab_length(rb) < size)) {
 542                 if (!rpcrdma_regbuf_realloc(rb, size, flags))
 543                         return false;
 544                 r_xprt->rx_stats.hardway_register_count += size;
 545         }
 546         return true;
 547 }
 548
 549 /**
 550  * xprt_rdma_allocate - allocate transport resources for an RPC
 551  * @task: RPC task
 552  *
 553  * Return values:
 554  *        0:    Success; rq_buffer points to RPC buffer to use
 555  *   ENOMEM:    Out of memory, call again later
 556  *      EIO:    A permanent error occurred, do not retry
 557  */
 558 static int
 559 xprt_rdma_allocate(struct rpc_task *task)
 560 {
 561         struct rpc_rqst *rqst = task->tk_rqstp;
 562         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 563         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 564         gfp_t flags = rpc_task_gfp_mask();
 565
 566         if (!rpcrdma_check_regbuf(r_xprt, req->rl_sendbuf, rqst->rq_callsize,
 567                                   flags))
 568                 goto out_fail;
 569         if (!rpcrdma_check_regbuf(r_xprt, req->rl_recvbuf, rqst->rq_rcvsize,
 570                                   flags))
 571                 goto out_fail;
 572
 573         rqst->rq_buffer = rdmab_data(req->rl_sendbuf);
 574         rqst->rq_rbuffer = rdmab_data(req->rl_recvbuf);
 575         return 0;
 576
 577 out_fail:
 578         return -ENOMEM;
 579 }
 580
 581 /**
 582  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 583  * @task: RPC task
 584  *
 585  * Caller guarantees rqst->rq_buffer is non-NULL.
 586  */
 587 static void
 588 xprt_rdma_free(struct rpc_task *task)
 589 {
 590         struct rpc_rqst *rqst = task->tk_rqstp;
 591         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 592
 593         if (unlikely(!list_empty(&req->rl_registered))) {
 594                 trace_xprtrdma_mrs_zap(task);
 595                 frwr_unmap_sync(rpcx_to_rdmax(rqst->rq_xprt), req);
 596         }
 597
 598         /* XXX: If the RPC is completing because of a signal and
 599          * not because a reply was received, we ought to ensure
 600          * that the Send completion has fired, so that memory
 601          * involved with the Send is not still visible to the NIC.
 602          */
 603 }
 604
 605 /**
 606  * xprt_rdma_send_request - marshal and send an RPC request
 607  * @rqst: RPC message in rq_snd_buf
 608  *
 609  * Caller holds the transport's write lock.
 610  *
 611  * Returns:
 612  *      %0 if the RPC message has been sent
 613  *      %-ENOTCONN if the caller should reconnect and call again
 614  *      %-EAGAIN if the caller should call again
 615  *      %-ENOBUFS if the caller should call again after a delay
 616  *      %-EMSGSIZE if encoding ran out of buffer space. The request
 617  *              was not sent. Do not try to send this message again.
 618  *      %-EIO if an I/O error occurred. The request was not sent.
 619  *              Do not try to send this message again.
 620  */
 621 static int
 622 xprt_rdma_send_request(struct rpc_rqst *rqst)
 623 {
 624         struct rpc_xprt *xprt = rqst->rq_xprt;
 625         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 626         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 627         int rc = 0;
 628
 629 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 630         if (unlikely(!rqst->rq_buffer))
 631                 return xprt_rdma_bc_send_reply(rqst);
 632 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 633
 634         if (!xprt_connected(xprt))
 635                 return -ENOTCONN;
 636
 637         if (!xprt_request_get_cong(xprt, rqst))
 638                 return -EBADSLT;
 639
 640         rc = rpcrdma_marshal_req(r_xprt, rqst);
 641         if (rc < 0)
 642                 goto failed_marshal;
 643
 644         /* Must suppress retransmit to maintain credits */
 645         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 646                 goto drop_connection;
 647         rqst->rq_xtime = ktime_get();
 648
 649         if (frwr_send(r_xprt, req))
 650                 goto drop_connection;
 651
 652         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 653
 654         /* An RPC with no reply will throw off credit accounting,
 655          * so drop the connection to reset the credit grant.
 656          */
 657         if (!rpc_reply_expected(rqst->rq_task))
 658                 goto drop_connection;
 659         return 0;
 660
 661 failed_marshal:
 662         if (rc != -ENOTCONN)
 663                 return rc;
 664 drop_connection:
 665         xprt_rdma_close(xprt);
 666         return -ENOTCONN;
 667 }
 668
 669 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 670 {
 671         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 672         long idle_time = 0;
 673
 674         if (xprt_connected(xprt))
 675                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 676
 677         seq_puts(seq, "\txprt:\trdma ");
 678         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 679                    0,   /* need a local port? */
 680                    xprt->stat.bind_count,
 681                    xprt->stat.connect_count,
 682                    xprt->stat.connect_time / HZ,
 683                    idle_time,
 684                    xprt->stat.sends,
 685                    xprt->stat.recvs,
 686                    xprt->stat.bad_xids,
 687                    xprt->stat.req_u,
 688                    xprt->stat.bklog_u);
 689         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 690                    r_xprt->rx_stats.read_chunk_count,
 691                    r_xprt->rx_stats.write_chunk_count,
 692                    r_xprt->rx_stats.reply_chunk_count,
 693                    r_xprt->rx_stats.total_rdma_request,
 694                    r_xprt->rx_stats.total_rdma_reply,
 695                    r_xprt->rx_stats.pullup_copy_count,
 696                    r_xprt->rx_stats.fixup_copy_count,
 697                    r_xprt->rx_stats.hardway_register_count,
 698                    r_xprt->rx_stats.failed_marshal_count,
 699                    r_xprt->rx_stats.bad_reply_count,
 700                    r_xprt->rx_stats.nomsg_call_count);
 701         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 702                    r_xprt->rx_stats.mrs_recycled,
 703                    r_xprt->rx_stats.mrs_orphaned,
 704                    r_xprt->rx_stats.mrs_allocated,
 705                    r_xprt->rx_stats.local_inv_needed,
 706                    r_xprt->rx_stats.empty_sendctx_q,
 707                    r_xprt->rx_stats.reply_waits_for_send);
 708 }
 709
 710 static int
 711 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 712 {
 713         return 0;
 714 }
 715
 716 static void
 717 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 718 {
 719 }
 720
 721 /*
 722  * Plumbing for rpc transport switch and kernel module
 723  */
 724
 725 static const struct rpc_xprt_ops xprt_rdma_procs = {
 726         .reserve_xprt           = xprt_reserve_xprt_cong,
 727         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 728         .alloc_slot             = xprt_rdma_alloc_slot,
 729         .free_slot              = xprt_rdma_free_slot,
 730         .release_request        = xprt_release_rqst_cong,       /* ditto */
 731         .wait_for_reply_request = xprt_wait_for_reply_request_def, /* ditto */
 732         .timer                  = xprt_rdma_timer,
 733         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 734         .set_port               = xprt_rdma_set_port,
 735         .connect                = xprt_rdma_connect,
 736         .buf_alloc              = xprt_rdma_allocate,
 737         .buf_free               = xprt_rdma_free,
 738         .send_request           = xprt_rdma_send_request,
 739         .close                  = xprt_rdma_close,
 740         .destroy                = xprt_rdma_destroy,
 741         .set_connect_timeout    = xprt_rdma_set_connect_timeout,
 742         .print_stats            = xprt_rdma_print_stats,
 743         .enable_swap            = xprt_rdma_enable_swap,
 744         .disable_swap           = xprt_rdma_disable_swap,
 745         .inject_disconnect      = xprt_rdma_inject_disconnect,
 746 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 747         .bc_setup               = xprt_rdma_bc_setup,
 748         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 749         .bc_num_slots           = xprt_rdma_bc_max_slots,
 750         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 751         .bc_destroy             = xprt_rdma_bc_destroy,
 752 #endif
 753 };
 754
 755 static struct xprt_class xprt_rdma = {
 756         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 757         .name                   = "rdma",
 758         .owner                  = THIS_MODULE,
 759         .ident                  = XPRT_TRANSPORT_RDMA,
 760         .setup                  = xprt_setup_rdma,
 761         .netid                  = { "rdma", "rdma6", "" },
 762 };
 763
 764 void xprt_rdma_cleanup(void)
 765 {
 766 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 767         if (sunrpc_table_header) {
 768                 unregister_sysctl_table(sunrpc_table_header);
 769                 sunrpc_table_header = NULL;
 770         }
 771 #endif
 772
 773         xprt_unregister_transport(&xprt_rdma);
 774         xprt_unregister_transport(&xprt_rdma_bc);
 775 }
 776
 777 int xprt_rdma_init(void)
 778 {
 779         int rc;
 780
 781         rc = xprt_register_transport(&xprt_rdma);
 782         if (rc)
 783                 return rc;
 784
 785         rc = xprt_register_transport(&xprt_rdma_bc);
 786         if (rc) {
 787                 xprt_unregister_transport(&xprt_rdma);
 788                 return rc;
 789         }
 790
 791 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 792         if (!sunrpc_table_header)
 793                 sunrpc_table_header = register_sysctl("sunrpc", xr_tunables_table);
 794 #endif
 795         return 0;
 796 }