net/sunrpc/xprtrdma/transport.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright (c) 2014-2017 Oracle.  All rights reserved.
   4  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the BSD-type
  10  * license below:
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  *
  16  *      Redistributions of source code must retain the above copyright
  17  *      notice, this list of conditions and the following disclaimer.
  18  *
  19  *      Redistributions in binary form must reproduce the above
  20  *      copyright notice, this list of conditions and the following
  21  *      disclaimer in the documentation and/or other materials provided
  22  *      with the distribution.
  23  *
  24  *      Neither the name of the Network Appliance, Inc. nor the names of
  25  *      its contributors may be used to endorse or promote products
  26  *      derived from this software without specific prior written
  27  *      permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  33  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 /*
  43  * transport.c
  44  *
  45  * This file contains the top-level implementation of an RPC RDMA
  46  * transport.
  47  *
  48  * Naming convention: functions beginning with xprt_ are part of the
  49  * transport switch. All others are RPC RDMA internal.
  50  */
  51
  52 #include <linux/module.h>
  53 #include <linux/slab.h>
  54 #include <linux/seq_file.h>
  55 #include <linux/smp.h>
  56
  57 #include <linux/sunrpc/addr.h>
  58 #include <linux/sunrpc/svc_rdma.h>
  59
  60 #include "xprt_rdma.h"
  61 #include <trace/events/rpcrdma.h>
  62
  63 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  64 # define RPCDBG_FACILITY        RPCDBG_TRANS
  65 #endif
  66
  67 /*
  68  * tunables
  69  */
  70
  71 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  72 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  73 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  74 unsigned int xprt_rdma_memreg_strategy          = RPCRDMA_FRWR;
  75 int xprt_rdma_pad_optimize;
  76
  77 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  78
  79 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  80 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  81 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  82 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  83 static unsigned int zero;
  84 static unsigned int max_padding = PAGE_SIZE;
  85 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  86 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  87 static unsigned int dummy;
  88
  89 static struct ctl_table_header *sunrpc_table_header;
  90
  91 static struct ctl_table xr_tunables_table[] = {
  92         {
  93                 .procname       = "rdma_slot_table_entries",
  94                 .data           = &xprt_rdma_slot_table_entries,
  95                 .maxlen         = sizeof(unsigned int),
  96                 .mode           = 0644,
  97                 .proc_handler   = proc_dointvec_minmax,
  98                 .extra1         = &min_slot_table_size,
  99                 .extra2         = &max_slot_table_size
 100         },
 101         {
 102                 .procname       = "rdma_max_inline_read",
 103                 .data           = &xprt_rdma_max_inline_read,
 104                 .maxlen         = sizeof(unsigned int),
 105                 .mode           = 0644,
 106                 .proc_handler   = proc_dointvec_minmax,
 107                 .extra1         = &min_inline_size,
 108                 .extra2         = &max_inline_size,
 109         },
 110         {
 111                 .procname       = "rdma_max_inline_write",
 112                 .data           = &xprt_rdma_max_inline_write,
 113                 .maxlen         = sizeof(unsigned int),
 114                 .mode           = 0644,
 115                 .proc_handler   = proc_dointvec_minmax,
 116                 .extra1         = &min_inline_size,
 117                 .extra2         = &max_inline_size,
 118         },
 119         {
 120                 .procname       = "rdma_inline_write_padding",
 121                 .data           = &dummy,
 122                 .maxlen         = sizeof(unsigned int),
 123                 .mode           = 0644,
 124                 .proc_handler   = proc_dointvec_minmax,
 125                 .extra1         = &zero,
 126                 .extra2         = &max_padding,
 127         },
 128         {
 129                 .procname       = "rdma_memreg_strategy",
 130                 .data           = &xprt_rdma_memreg_strategy,
 131                 .maxlen         = sizeof(unsigned int),
 132                 .mode           = 0644,
 133                 .proc_handler   = proc_dointvec_minmax,
 134                 .extra1         = &min_memreg,
 135                 .extra2         = &max_memreg,
 136         },
 137         {
 138                 .procname       = "rdma_pad_optimize",
 139                 .data           = &xprt_rdma_pad_optimize,
 140                 .maxlen         = sizeof(unsigned int),
 141                 .mode           = 0644,
 142                 .proc_handler   = proc_dointvec,
 143         },
 144         { },
 145 };
 146
 147 static struct ctl_table sunrpc_table[] = {
 148         {
 149                 .procname       = "sunrpc",
 150                 .mode           = 0555,
 151                 .child          = xr_tunables_table
 152         },
 153         { },
 154 };
 155
 156 #endif
 157
 158 static const struct rpc_xprt_ops xprt_rdma_procs;
 159
 160 static void
 161 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 162 {
 163         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 164         char buf[20];
 165
 166         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 167         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 168
 169         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 170 }
 171
 172 static void
 173 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 174 {
 175         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 176         char buf[40];
 177
 178         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 179         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 180
 181         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 182 }
 183
 184 void
 185 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 186 {
 187         char buf[128];
 188
 189         switch (sap->sa_family) {
 190         case AF_INET:
 191                 xprt_rdma_format_addresses4(xprt, sap);
 192                 break;
 193         case AF_INET6:
 194                 xprt_rdma_format_addresses6(xprt, sap);
 195                 break;
 196         default:
 197                 pr_err("rpcrdma: Unrecognized address family\n");
 198                 return;
 199         }
 200
 201         (void)rpc_ntop(sap, buf, sizeof(buf));
 202         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 203
 204         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 205         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 206
 207         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 208         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 209
 210         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 211 }
 212
 213 void
 214 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 215 {
 216         unsigned int i;
 217
 218         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 219                 switch (i) {
 220                 case RPC_DISPLAY_PROTO:
 221                 case RPC_DISPLAY_NETID:
 222                         continue;
 223                 default:
 224                         kfree(xprt->address_strings[i]);
 225                 }
 226 }
 227
 228 void
 229 rpcrdma_conn_func(struct rpcrdma_ep *ep)
 230 {
 231         schedule_delayed_work(&ep->rep_connect_worker, 0);
 232 }
 233
 234 void
 235 rpcrdma_connect_worker(struct work_struct *work)
 236 {
 237         struct rpcrdma_ep *ep =
 238                 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
 239         struct rpcrdma_xprt *r_xprt =
 240                 container_of(ep, struct rpcrdma_xprt, rx_ep);
 241         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 242
 243         spin_lock_bh(&xprt->transport_lock);
 244         if (ep->rep_connected > 0) {
 245                 if (!xprt_test_and_set_connected(xprt)) {
 246                         xprt->stat.connect_count++;
 247                         xprt->stat.connect_time += (long)jiffies -
 248                                                    xprt->stat.connect_start;
 249                         xprt_wake_pending_tasks(xprt, 0);
 250                 }
 251         } else {
 252                 if (xprt_test_and_clear_connected(xprt))
 253                         xprt_wake_pending_tasks(xprt, -ENOTCONN);
 254         }
 255         spin_unlock_bh(&xprt->transport_lock);
 256 }
 257
 258 static void
 259 xprt_rdma_connect_worker(struct work_struct *work)
 260 {
 261         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 262                                                    rx_connect_worker.work);
 263         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 264         int rc = 0;
 265
 266         xprt_clear_connected(xprt);
 267
 268         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 269         if (rc)
 270                 xprt_wake_pending_tasks(xprt, rc);
 271
 272         xprt_clear_connecting(xprt);
 273 }
 274
 275 static void
 276 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 277 {
 278         struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
 279                                                    rx_xprt);
 280
 281         trace_xprtrdma_inject_dsc(r_xprt);
 282         rdma_disconnect(r_xprt->rx_ia.ri_id);
 283 }
 284
 285 /*
 286  * xprt_rdma_destroy
 287  *
 288  * Destroy the xprt.
 289  * Free all memory associated with the object, including its own.
 290  * NOTE: none of the *destroy methods free memory for their top-level
 291  * objects, even though they may have allocated it (they do free
 292  * private memory). It's up to the caller to handle it. In this
 293  * case (RDMA transport), all structure memory is inlined with the
 294  * struct rpcrdma_xprt.
 295  */
 296 static void
 297 xprt_rdma_destroy(struct rpc_xprt *xprt)
 298 {
 299         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 300
 301         trace_xprtrdma_destroy(r_xprt);
 302
 303         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 304
 305         xprt_clear_connected(xprt);
 306
 307         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 308         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 309         rpcrdma_ia_close(&r_xprt->rx_ia);
 310
 311         xprt_rdma_free_addresses(xprt);
 312         xprt_free(xprt);
 313
 314         module_put(THIS_MODULE);
 315 }
 316
 317 static const struct rpc_timeout xprt_rdma_default_timeout = {
 318         .to_initval = 60 * HZ,
 319         .to_maxval = 60 * HZ,
 320 };
 321
 322 /**
 323  * xprt_setup_rdma - Set up transport to use RDMA
 324  *
 325  * @args: rpc transport arguments
 326  */
 327 static struct rpc_xprt *
 328 xprt_setup_rdma(struct xprt_create *args)
 329 {
 330         struct rpcrdma_create_data_internal cdata;
 331         struct rpc_xprt *xprt;
 332         struct rpcrdma_xprt *new_xprt;
 333         struct rpcrdma_ep *new_ep;
 334         struct sockaddr *sap;
 335         int rc;
 336
 337         if (args->addrlen > sizeof(xprt->addr)) {
 338                 dprintk("RPC:       %s: address too large\n", __func__);
 339                 return ERR_PTR(-EBADF);
 340         }
 341
 342         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt), 0, 0);
 343         if (xprt == NULL) {
 344                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 345                         __func__);
 346                 return ERR_PTR(-ENOMEM);
 347         }
 348
 349         /* 60 second timeout, no retries */
 350         xprt->timeout = &xprt_rdma_default_timeout;
 351         xprt->bind_timeout = RPCRDMA_BIND_TO;
 352         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 353         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 354
 355         xprt->resvport = 0;             /* privileged port not needed */
 356         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 357         xprt->ops = &xprt_rdma_procs;
 358
 359         /*
 360          * Set up RDMA-specific connect data.
 361          */
 362         sap = args->dstaddr;
 363
 364         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 365          * address, for any side protocols which peek at it */
 366         xprt->prot = IPPROTO_TCP;
 367         xprt->addrlen = args->addrlen;
 368         memcpy(&xprt->addr, sap, xprt->addrlen);
 369
 370         if (rpc_get_port(sap))
 371                 xprt_set_bound(xprt);
 372         xprt_rdma_format_addresses(xprt, sap);
 373
 374         cdata.max_requests = xprt_rdma_slot_table_entries;
 375
 376         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 377         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 378
 379         cdata.inline_wsize = xprt_rdma_max_inline_write;
 380         if (cdata.inline_wsize > cdata.wsize)
 381                 cdata.inline_wsize = cdata.wsize;
 382
 383         cdata.inline_rsize = xprt_rdma_max_inline_read;
 384         if (cdata.inline_rsize > cdata.rsize)
 385                 cdata.inline_rsize = cdata.rsize;
 386
 387         /*
 388          * Create new transport instance, which includes initialized
 389          *  o ia
 390          *  o endpoint
 391          *  o buffers
 392          */
 393
 394         new_xprt = rpcx_to_rdmax(xprt);
 395
 396         rc = rpcrdma_ia_open(new_xprt);
 397         if (rc)
 398                 goto out1;
 399
 400         /*
 401          * initialize and create ep
 402          */
 403         new_xprt->rx_data = cdata;
 404         new_ep = &new_xprt->rx_ep;
 405
 406         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 407                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 408         if (rc)
 409                 goto out2;
 410
 411         rc = rpcrdma_buffer_create(new_xprt);
 412         if (rc)
 413                 goto out3;
 414
 415         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 416                           xprt_rdma_connect_worker);
 417
 418         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 419         if (xprt->max_payload == 0)
 420                 goto out4;
 421         xprt->max_payload <<= PAGE_SHIFT;
 422         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 423                 __func__, xprt->max_payload);
 424
 425         if (!try_module_get(THIS_MODULE))
 426                 goto out4;
 427
 428         dprintk("RPC:       %s: %s:%s\n", __func__,
 429                 xprt->address_strings[RPC_DISPLAY_ADDR],
 430                 xprt->address_strings[RPC_DISPLAY_PORT]);
 431         trace_xprtrdma_create(new_xprt);
 432         return xprt;
 433
 434 out4:
 435         rpcrdma_buffer_destroy(&new_xprt->rx_buf);
 436         rc = -ENODEV;
 437 out3:
 438         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 439 out2:
 440         rpcrdma_ia_close(&new_xprt->rx_ia);
 441 out1:
 442         trace_xprtrdma_destroy(new_xprt);
 443         xprt_rdma_free_addresses(xprt);
 444         xprt_free(xprt);
 445         return ERR_PTR(rc);
 446 }
 447
 448 /**
 449  * xprt_rdma_close - Close down RDMA connection
 450  * @xprt: generic transport to be closed
 451  *
 452  * Called during transport shutdown reconnect, or device
 453  * removal. Caller holds the transport's write lock.
 454  */
 455 static void
 456 xprt_rdma_close(struct rpc_xprt *xprt)
 457 {
 458         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 459         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 460         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 461
 462         dprintk("RPC:       %s: closing xprt %p\n", __func__, xprt);
 463
 464         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 465                 xprt_clear_connected(xprt);
 466                 rpcrdma_ia_remove(ia);
 467                 return;
 468         }
 469         if (ep->rep_connected == -ENODEV)
 470                 return;
 471         if (ep->rep_connected > 0)
 472                 xprt->reestablish_timeout = 0;
 473         xprt_disconnect_done(xprt);
 474         rpcrdma_ep_disconnect(ep, ia);
 475
 476         /* Prepare @xprt for the next connection by reinitializing
 477          * its credit grant to one (see RFC 8166, Section 3.3.3).
 478          */
 479         r_xprt->rx_buf.rb_credits = 1;
 480         xprt->cwnd = RPC_CWNDSHIFT;
 481 }
 482
 483 /**
 484  * xprt_rdma_set_port - update server port with rpcbind result
 485  * @xprt: controlling RPC transport
 486  * @port: new port value
 487  *
 488  * Transport connect status is unchanged.
 489  */
 490 static void
 491 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 492 {
 493         struct sockaddr *sap = (struct sockaddr *)&xprt->addr;
 494         char buf[8];
 495
 496         dprintk("RPC:       %s: setting port for xprt %p (%s:%s) to %u\n",
 497                 __func__, xprt,
 498                 xprt->address_strings[RPC_DISPLAY_ADDR],
 499                 xprt->address_strings[RPC_DISPLAY_PORT],
 500                 port);
 501
 502         rpc_set_port(sap, port);
 503
 504         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 505         snprintf(buf, sizeof(buf), "%u", port);
 506         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 507
 508         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 509         snprintf(buf, sizeof(buf), "%4hx", port);
 510         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 511 }
 512
 513 /**
 514  * xprt_rdma_timer - invoked when an RPC times out
 515  * @xprt: controlling RPC transport
 516  * @task: RPC task that timed out
 517  *
 518  * Invoked when the transport is still connected, but an RPC
 519  * retransmit timeout occurs.
 520  *
 521  * Since RDMA connections don't have a keep-alive, forcibly
 522  * disconnect and retry to connect. This drives full
 523  * detection of the network path, and retransmissions of
 524  * all pending RPCs.
 525  */
 526 static void
 527 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 528 {
 529         xprt_force_disconnect(xprt);
 530 }
 531
 532 static void
 533 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 534 {
 535         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 536
 537         if (r_xprt->rx_ep.rep_connected != 0) {
 538                 /* Reconnect */
 539                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 540                                       xprt->reestablish_timeout);
 541                 xprt->reestablish_timeout <<= 1;
 542                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 543                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 544                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 545                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 546         } else {
 547                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 548                 if (!RPC_IS_ASYNC(task))
 549                         flush_delayed_work(&r_xprt->rx_connect_worker);
 550         }
 551 }
 552
 553 /**
 554  * xprt_rdma_alloc_slot - allocate an rpc_rqst
 555  * @xprt: controlling RPC transport
 556  * @task: RPC task requesting a fresh rpc_rqst
 557  *
 558  * tk_status values:
 559  *      %0 if task->tk_rqstp points to a fresh rpc_rqst
 560  *      %-EAGAIN if no rpc_rqst is available; queued on backlog
 561  */
 562 static void
 563 xprt_rdma_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
 564 {
 565         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 566         struct rpcrdma_req *req;
 567
 568         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 569         if (!req)
 570                 goto out_sleep;
 571         task->tk_rqstp = &req->rl_slot;
 572         task->tk_status = 0;
 573         return;
 574
 575 out_sleep:
 576         rpc_sleep_on(&xprt->backlog, task, NULL);
 577         task->tk_status = -EAGAIN;
 578 }
 579
 580 /**
 581  * xprt_rdma_free_slot - release an rpc_rqst
 582  * @xprt: controlling RPC transport
 583  * @rqst: rpc_rqst to release
 584  *
 585  */
 586 static void
 587 xprt_rdma_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *rqst)
 588 {
 589         memset(rqst, 0, sizeof(*rqst));
 590         rpcrdma_buffer_put(rpcr_to_rdmar(rqst));
 591         rpc_wake_up_next(&xprt->backlog);
 592 }
 593
 594 static bool
 595 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 596                     size_t size, gfp_t flags)
 597 {
 598         struct rpcrdma_regbuf *rb;
 599
 600         if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
 601                 return true;
 602
 603         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 604         if (IS_ERR(rb))
 605                 return false;
 606
 607         rpcrdma_free_regbuf(req->rl_sendbuf);
 608         r_xprt->rx_stats.hardway_register_count += size;
 609         req->rl_sendbuf = rb;
 610         return true;
 611 }
 612
 613 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
 614  * The decision to use a Reply chunk is made later in
 615  * rpcrdma_marshal_req. This buffer is registered at that time.
 616  *
 617  * Otherwise, the associated RPC Reply arrives in a separate
 618  * Receive buffer, arbitrarily chosen by the HCA. The buffer
 619  * allocated here for the RPC Reply is not utilized in that
 620  * case. See rpcrdma_inline_fixup.
 621  *
 622  * A regbuf is used here to remember the buffer size.
 623  */
 624 static bool
 625 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 626                     size_t size, gfp_t flags)
 627 {
 628         struct rpcrdma_regbuf *rb;
 629
 630         if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
 631                 return true;
 632
 633         rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
 634         if (IS_ERR(rb))
 635                 return false;
 636
 637         rpcrdma_free_regbuf(req->rl_recvbuf);
 638         r_xprt->rx_stats.hardway_register_count += size;
 639         req->rl_recvbuf = rb;
 640         return true;
 641 }
 642
 643 /**
 644  * xprt_rdma_allocate - allocate transport resources for an RPC
 645  * @task: RPC task
 646  *
 647  * Return values:
 648  *        0:    Success; rq_buffer points to RPC buffer to use
 649  *   ENOMEM:    Out of memory, call again later
 650  *      EIO:    A permanent error occurred, do not retry
 651  *
 652  * The RDMA allocate/free functions need the task structure as a place
 653  * to hide the struct rpcrdma_req, which is necessary for the actual
 654  * send/recv sequence.
 655  *
 656  * xprt_rdma_allocate provides buffers that are already mapped for
 657  * DMA, and a local DMA lkey is provided for each.
 658  */
 659 static int
 660 xprt_rdma_allocate(struct rpc_task *task)
 661 {
 662         struct rpc_rqst *rqst = task->tk_rqstp;
 663         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 664         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 665         gfp_t flags;
 666
 667         flags = RPCRDMA_DEF_GFP;
 668         if (RPC_IS_ASYNC(task))
 669                 flags = GFP_NOWAIT | __GFP_NOWARN;
 670         if (RPC_IS_SWAPPER(task))
 671                 flags |= __GFP_MEMALLOC;
 672
 673         if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
 674                 goto out_fail;
 675         if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
 676                 goto out_fail;
 677
 678         rqst->rq_buffer = req->rl_sendbuf->rg_base;
 679         rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
 680         trace_xprtrdma_allocate(task, req);
 681         return 0;
 682
 683 out_fail:
 684         trace_xprtrdma_allocate(task, NULL);
 685         return -ENOMEM;
 686 }
 687
 688 /**
 689  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 690  * @task: RPC task
 691  *
 692  * Caller guarantees rqst->rq_buffer is non-NULL.
 693  */
 694 static void
 695 xprt_rdma_free(struct rpc_task *task)
 696 {
 697         struct rpc_rqst *rqst = task->tk_rqstp;
 698         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 699         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 700
 701         if (test_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags))
 702                 rpcrdma_release_rqst(r_xprt, req);
 703         trace_xprtrdma_rpc_done(task, req);
 704 }
 705
 706 /**
 707  * xprt_rdma_send_request - marshal and send an RPC request
 708  * @task: RPC task with an RPC message in rq_snd_buf
 709  *
 710  * Caller holds the transport's write lock.
 711  *
 712  * Returns:
 713  *      %0 if the RPC message has been sent
 714  *      %-ENOTCONN if the caller should reconnect and call again
 715  *      %-EAGAIN if the caller should call again
 716  *      %-ENOBUFS if the caller should call again after a delay
 717  *      %-EIO if a permanent error occurred and the request was not
 718  *              sent. Do not try to send this message again.
 719  */
 720 static int
 721 xprt_rdma_send_request(struct rpc_task *task)
 722 {
 723         struct rpc_rqst *rqst = task->tk_rqstp;
 724         struct rpc_xprt *xprt = rqst->rq_xprt;
 725         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 726         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 727         int rc = 0;
 728
 729 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 730         if (unlikely(!rqst->rq_buffer))
 731                 return xprt_rdma_bc_send_reply(rqst);
 732 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 733
 734         if (!xprt_connected(xprt))
 735                 goto drop_connection;
 736
 737         rc = rpcrdma_marshal_req(r_xprt, rqst);
 738         if (rc < 0)
 739                 goto failed_marshal;
 740
 741         /* Must suppress retransmit to maintain credits */
 742         if (rqst->rq_connect_cookie == xprt->connect_cookie)
 743                 goto drop_connection;
 744         rqst->rq_xtime = ktime_get();
 745
 746         __set_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags);
 747         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 748                 goto drop_connection;
 749
 750         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 751         rqst->rq_bytes_sent = 0;
 752
 753         /* An RPC with no reply will throw off credit accounting,
 754          * so drop the connection to reset the credit grant.
 755          */
 756         if (!rpc_reply_expected(task))
 757                 goto drop_connection;
 758         return 0;
 759
 760 failed_marshal:
 761         if (rc != -ENOTCONN)
 762                 return rc;
 763 drop_connection:
 764         xprt_disconnect_done(xprt);
 765         return -ENOTCONN;       /* implies disconnect */
 766 }
 767
 768 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 769 {
 770         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 771         long idle_time = 0;
 772
 773         if (xprt_connected(xprt))
 774                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 775
 776         seq_puts(seq, "\txprt:\trdma ");
 777         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 778                    0,   /* need a local port? */
 779                    xprt->stat.bind_count,
 780                    xprt->stat.connect_count,
 781                    xprt->stat.connect_time,
 782                    idle_time,
 783                    xprt->stat.sends,
 784                    xprt->stat.recvs,
 785                    xprt->stat.bad_xids,
 786                    xprt->stat.req_u,
 787                    xprt->stat.bklog_u);
 788         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 789                    r_xprt->rx_stats.read_chunk_count,
 790                    r_xprt->rx_stats.write_chunk_count,
 791                    r_xprt->rx_stats.reply_chunk_count,
 792                    r_xprt->rx_stats.total_rdma_request,
 793                    r_xprt->rx_stats.total_rdma_reply,
 794                    r_xprt->rx_stats.pullup_copy_count,
 795                    r_xprt->rx_stats.fixup_copy_count,
 796                    r_xprt->rx_stats.hardway_register_count,
 797                    r_xprt->rx_stats.failed_marshal_count,
 798                    r_xprt->rx_stats.bad_reply_count,
 799                    r_xprt->rx_stats.nomsg_call_count);
 800         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 801                    r_xprt->rx_stats.mrs_recovered,
 802                    r_xprt->rx_stats.mrs_orphaned,
 803                    r_xprt->rx_stats.mrs_allocated,
 804                    r_xprt->rx_stats.local_inv_needed,
 805                    r_xprt->rx_stats.empty_sendctx_q,
 806                    r_xprt->rx_stats.reply_waits_for_send);
 807 }
 808
 809 static int
 810 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 811 {
 812         return 0;
 813 }
 814
 815 static void
 816 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 817 {
 818 }
 819
 820 /*
 821  * Plumbing for rpc transport switch and kernel module
 822  */
 823
 824 static const struct rpc_xprt_ops xprt_rdma_procs = {
 825         .reserve_xprt           = xprt_reserve_xprt_cong,
 826         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 827         .alloc_slot             = xprt_rdma_alloc_slot,
 828         .free_slot              = xprt_rdma_free_slot,
 829         .release_request        = xprt_release_rqst_cong,       /* ditto */
 830         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 831         .timer                  = xprt_rdma_timer,
 832         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 833         .set_port               = xprt_rdma_set_port,
 834         .connect                = xprt_rdma_connect,
 835         .buf_alloc              = xprt_rdma_allocate,
 836         .buf_free               = xprt_rdma_free,
 837         .send_request           = xprt_rdma_send_request,
 838         .close                  = xprt_rdma_close,
 839         .destroy                = xprt_rdma_destroy,
 840         .print_stats            = xprt_rdma_print_stats,
 841         .enable_swap            = xprt_rdma_enable_swap,
 842         .disable_swap           = xprt_rdma_disable_swap,
 843         .inject_disconnect      = xprt_rdma_inject_disconnect,
 844 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 845         .bc_setup               = xprt_rdma_bc_setup,
 846         .bc_up                  = xprt_rdma_bc_up,
 847         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 848         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 849         .bc_destroy             = xprt_rdma_bc_destroy,
 850 #endif
 851 };
 852
 853 static struct xprt_class xprt_rdma = {
 854         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 855         .name                   = "rdma",
 856         .owner                  = THIS_MODULE,
 857         .ident                  = XPRT_TRANSPORT_RDMA,
 858         .setup                  = xprt_setup_rdma,
 859         .netid                  = { "rdma", "rdma6", "" },
 860 };
 861
 862 void xprt_rdma_cleanup(void)
 863 {
 864         int rc;
 865
 866         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 867 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 868         if (sunrpc_table_header) {
 869                 unregister_sysctl_table(sunrpc_table_header);
 870                 sunrpc_table_header = NULL;
 871         }
 872 #endif
 873         rc = xprt_unregister_transport(&xprt_rdma);
 874         if (rc)
 875                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 876                         __func__, rc);
 877
 878         rpcrdma_destroy_wq();
 879
 880         rc = xprt_unregister_transport(&xprt_rdma_bc);
 881         if (rc)
 882                 dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
 883                         __func__, rc);
 884 }
 885
 886 int xprt_rdma_init(void)
 887 {
 888         int rc;
 889
 890         rc = rpcrdma_alloc_wq();
 891         if (rc)
 892                 return rc;
 893
 894         rc = xprt_register_transport(&xprt_rdma);
 895         if (rc) {
 896                 rpcrdma_destroy_wq();
 897                 return rc;
 898         }
 899
 900         rc = xprt_register_transport(&xprt_rdma_bc);
 901         if (rc) {
 902                 xprt_unregister_transport(&xprt_rdma);
 903                 rpcrdma_destroy_wq();
 904                 return rc;
 905         }
 906
 907         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 908
 909         dprintk("Defaults:\n");
 910         dprintk("\tSlots %d\n"
 911                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 912                 xprt_rdma_slot_table_entries,
 913                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 914         dprintk("\tPadding 0\n\tMemreg %d\n", xprt_rdma_memreg_strategy);
 915
 916 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 917         if (!sunrpc_table_header)
 918                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 919 #endif
 920         return 0;
 921 }