net/sunrpc/xprtrdma/transport.c

   1 /*
   2  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the BSD-type
   8  * license below:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  *      Redistributions of source code must retain the above copyright
  15  *      notice, this list of conditions and the following disclaimer.
  16  *
  17  *      Redistributions in binary form must reproduce the above
  18  *      copyright notice, this list of conditions and the following
  19  *      disclaimer in the documentation and/or other materials provided
  20  *      with the distribution.
  21  *
  22  *      Neither the name of the Network Appliance, Inc. nor the names of
  23  *      its contributors may be used to endorse or promote products
  24  *      derived from this software without specific prior written
  25  *      permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  */
  39
  40 /*
  41  * transport.c
  42  *
  43  * This file contains the top-level implementation of an RPC RDMA
  44  * transport.
  45  *
  46  * Naming convention: functions beginning with xprt_ are part of the
  47  * transport switch. All others are RPC RDMA internal.
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/init.h>
  52 #include <linux/slab.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/sunrpc/addr.h>
  55
  56 #include "xprt_rdma.h"
  57
  58 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  59 # define RPCDBG_FACILITY        RPCDBG_TRANS
  60 #endif
  61
  62 MODULE_LICENSE("Dual BSD/GPL");
  63
  64 MODULE_DESCRIPTION("RPC/RDMA Transport for Linux kernel NFS");
  65 MODULE_AUTHOR("Network Appliance, Inc.");
  66
  67 /*
  68  * tunables
  69  */
  70
  71 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  72 static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  73 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  74 static unsigned int xprt_rdma_inline_write_padding;
  75 static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
  76                 int xprt_rdma_pad_optimize = 1;
  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 zero;
  83 static unsigned int max_padding = PAGE_SIZE;
  84 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  85 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  86
  87 static struct ctl_table_header *sunrpc_table_header;
  88
  89 static struct ctl_table xr_tunables_table[] = {
  90         {
  91                 .procname       = "rdma_slot_table_entries",
  92                 .data           = &xprt_rdma_slot_table_entries,
  93                 .maxlen         = sizeof(unsigned int),
  94                 .mode           = 0644,
  95                 .proc_handler   = proc_dointvec_minmax,
  96                 .extra1         = &min_slot_table_size,
  97                 .extra2         = &max_slot_table_size
  98         },
  99         {
 100                 .procname       = "rdma_max_inline_read",
 101                 .data           = &xprt_rdma_max_inline_read,
 102                 .maxlen         = sizeof(unsigned int),
 103                 .mode           = 0644,
 104                 .proc_handler   = proc_dointvec,
 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,
 112         },
 113         {
 114                 .procname       = "rdma_inline_write_padding",
 115                 .data           = &xprt_rdma_inline_write_padding,
 116                 .maxlen         = sizeof(unsigned int),
 117                 .mode           = 0644,
 118                 .proc_handler   = proc_dointvec_minmax,
 119                 .extra1         = &zero,
 120                 .extra2         = &max_padding,
 121         },
 122         {
 123                 .procname       = "rdma_memreg_strategy",
 124                 .data           = &xprt_rdma_memreg_strategy,
 125                 .maxlen         = sizeof(unsigned int),
 126                 .mode           = 0644,
 127                 .proc_handler   = proc_dointvec_minmax,
 128                 .extra1         = &min_memreg,
 129                 .extra2         = &max_memreg,
 130         },
 131         {
 132                 .procname       = "rdma_pad_optimize",
 133                 .data           = &xprt_rdma_pad_optimize,
 134                 .maxlen         = sizeof(unsigned int),
 135                 .mode           = 0644,
 136                 .proc_handler   = proc_dointvec,
 137         },
 138         { },
 139 };
 140
 141 static struct ctl_table sunrpc_table[] = {
 142         {
 143                 .procname       = "sunrpc",
 144                 .mode           = 0555,
 145                 .child          = xr_tunables_table
 146         },
 147         { },
 148 };
 149
 150 #endif
 151
 152 #define RPCRDMA_BIND_TO         (60U * HZ)
 153 #define RPCRDMA_INIT_REEST_TO   (5U * HZ)
 154 #define RPCRDMA_MAX_REEST_TO    (30U * HZ)
 155 #define RPCRDMA_IDLE_DISC_TO    (5U * 60 * HZ)
 156
 157 static struct rpc_xprt_ops xprt_rdma_procs;     /* forward reference */
 158
 159 static void
 160 xprt_rdma_format_addresses(struct rpc_xprt *xprt)
 161 {
 162         struct sockaddr *sap = (struct sockaddr *)
 163                                         &rpcx_to_rdmad(xprt).addr;
 164         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 165         char buf[64];
 166
 167         (void)rpc_ntop(sap, buf, sizeof(buf));
 168         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 169
 170         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 171         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 172
 173         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 174
 175         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 176         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 177
 178         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 179         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 180
 181         /* netid */
 182         xprt->address_strings[RPC_DISPLAY_NETID] = "rdma";
 183 }
 184
 185 static void
 186 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 187 {
 188         unsigned int i;
 189
 190         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 191                 switch (i) {
 192                 case RPC_DISPLAY_PROTO:
 193                 case RPC_DISPLAY_NETID:
 194                         continue;
 195                 default:
 196                         kfree(xprt->address_strings[i]);
 197                 }
 198 }
 199
 200 static void
 201 xprt_rdma_connect_worker(struct work_struct *work)
 202 {
 203         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 204                                                    rx_connect_worker.work);
 205         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 206         int rc = 0;
 207
 208         xprt_clear_connected(xprt);
 209
 210         dprintk("RPC:       %s: %sconnect\n", __func__,
 211                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 212         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 213         if (rc)
 214                 xprt_wake_pending_tasks(xprt, rc);
 215
 216         dprintk("RPC:       %s: exit\n", __func__);
 217         xprt_clear_connecting(xprt);
 218 }
 219
 220 /*
 221  * xprt_rdma_destroy
 222  *
 223  * Destroy the xprt.
 224  * Free all memory associated with the object, including its own.
 225  * NOTE: none of the *destroy methods free memory for their top-level
 226  * objects, even though they may have allocated it (they do free
 227  * private memory). It's up to the caller to handle it. In this
 228  * case (RDMA transport), all structure memory is inlined with the
 229  * struct rpcrdma_xprt.
 230  */
 231 static void
 232 xprt_rdma_destroy(struct rpc_xprt *xprt)
 233 {
 234         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 235
 236         dprintk("RPC:       %s: called\n", __func__);
 237
 238         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 239
 240         xprt_clear_connected(xprt);
 241
 242         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 243         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 244         rpcrdma_ia_close(&r_xprt->rx_ia);
 245
 246         xprt_rdma_free_addresses(xprt);
 247
 248         xprt_free(xprt);
 249
 250         dprintk("RPC:       %s: returning\n", __func__);
 251
 252         module_put(THIS_MODULE);
 253 }
 254
 255 static const struct rpc_timeout xprt_rdma_default_timeout = {
 256         .to_initval = 60 * HZ,
 257         .to_maxval = 60 * HZ,
 258 };
 259
 260 /**
 261  * xprt_setup_rdma - Set up transport to use RDMA
 262  *
 263  * @args: rpc transport arguments
 264  */
 265 static struct rpc_xprt *
 266 xprt_setup_rdma(struct xprt_create *args)
 267 {
 268         struct rpcrdma_create_data_internal cdata;
 269         struct rpc_xprt *xprt;
 270         struct rpcrdma_xprt *new_xprt;
 271         struct rpcrdma_ep *new_ep;
 272         struct sockaddr_in *sin;
 273         int rc;
 274
 275         if (args->addrlen > sizeof(xprt->addr)) {
 276                 dprintk("RPC:       %s: address too large\n", __func__);
 277                 return ERR_PTR(-EBADF);
 278         }
 279
 280         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 281                         xprt_rdma_slot_table_entries,
 282                         xprt_rdma_slot_table_entries);
 283         if (xprt == NULL) {
 284                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 285                         __func__);
 286                 return ERR_PTR(-ENOMEM);
 287         }
 288
 289         /* 60 second timeout, no retries */
 290         xprt->timeout = &xprt_rdma_default_timeout;
 291         xprt->bind_timeout = RPCRDMA_BIND_TO;
 292         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 293         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 294
 295         xprt->resvport = 0;             /* privileged port not needed */
 296         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 297         xprt->ops = &xprt_rdma_procs;
 298
 299         /*
 300          * Set up RDMA-specific connect data.
 301          */
 302
 303         /* Put server RDMA address in local cdata */
 304         memcpy(&cdata.addr, args->dstaddr, args->addrlen);
 305
 306         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 307          * address, for any side protocols which peek at it */
 308         xprt->prot = IPPROTO_TCP;
 309         xprt->addrlen = args->addrlen;
 310         memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
 311
 312         sin = (struct sockaddr_in *)&cdata.addr;
 313         if (ntohs(sin->sin_port) != 0)
 314                 xprt_set_bound(xprt);
 315
 316         dprintk("RPC:       %s: %pI4:%u\n",
 317                 __func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
 318
 319         /* Set max requests */
 320         cdata.max_requests = xprt->max_reqs;
 321
 322         /* Set some length limits */
 323         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 324         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 325
 326         cdata.inline_wsize = xprt_rdma_max_inline_write;
 327         if (cdata.inline_wsize > cdata.wsize)
 328                 cdata.inline_wsize = cdata.wsize;
 329
 330         cdata.inline_rsize = xprt_rdma_max_inline_read;
 331         if (cdata.inline_rsize > cdata.rsize)
 332                 cdata.inline_rsize = cdata.rsize;
 333
 334         cdata.padding = xprt_rdma_inline_write_padding;
 335
 336         /*
 337          * Create new transport instance, which includes initialized
 338          *  o ia
 339          *  o endpoint
 340          *  o buffers
 341          */
 342
 343         new_xprt = rpcx_to_rdmax(xprt);
 344
 345         rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
 346                                 xprt_rdma_memreg_strategy);
 347         if (rc)
 348                 goto out1;
 349
 350         /*
 351          * initialize and create ep
 352          */
 353         new_xprt->rx_data = cdata;
 354         new_ep = &new_xprt->rx_ep;
 355         new_ep->rep_remote_addr = cdata.addr;
 356
 357         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 358                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 359         if (rc)
 360                 goto out2;
 361
 362         /*
 363          * Allocate pre-registered send and receive buffers for headers and
 364          * any inline data. Also specify any padding which will be provided
 365          * from a preregistered zero buffer.
 366          */
 367         rc = rpcrdma_buffer_create(new_xprt);
 368         if (rc)
 369                 goto out3;
 370
 371         /*
 372          * Register a callback for connection events. This is necessary because
 373          * connection loss notification is async. We also catch connection loss
 374          * when reaping receives.
 375          */
 376         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 377                           xprt_rdma_connect_worker);
 378
 379         xprt_rdma_format_addresses(xprt);
 380         xprt->max_payload = rpcrdma_max_payload(new_xprt);
 381         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 382                 __func__, xprt->max_payload);
 383
 384         if (!try_module_get(THIS_MODULE))
 385                 goto out4;
 386
 387         return xprt;
 388
 389 out4:
 390         xprt_rdma_free_addresses(xprt);
 391         rc = -EINVAL;
 392 out3:
 393         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 394 out2:
 395         rpcrdma_ia_close(&new_xprt->rx_ia);
 396 out1:
 397         xprt_free(xprt);
 398         return ERR_PTR(rc);
 399 }
 400
 401 /*
 402  * Close a connection, during shutdown or timeout/reconnect
 403  */
 404 static void
 405 xprt_rdma_close(struct rpc_xprt *xprt)
 406 {
 407         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 408
 409         dprintk("RPC:       %s: closing\n", __func__);
 410         if (r_xprt->rx_ep.rep_connected > 0)
 411                 xprt->reestablish_timeout = 0;
 412         xprt_disconnect_done(xprt);
 413         rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 414 }
 415
 416 static void
 417 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 418 {
 419         struct sockaddr_in *sap;
 420
 421         sap = (struct sockaddr_in *)&xprt->addr;
 422         sap->sin_port = htons(port);
 423         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 424         sap->sin_port = htons(port);
 425         dprintk("RPC:       %s: %u\n", __func__, port);
 426 }
 427
 428 static void
 429 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 430 {
 431         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 432
 433         if (r_xprt->rx_ep.rep_connected != 0) {
 434                 /* Reconnect */
 435                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 436                                       xprt->reestablish_timeout);
 437                 xprt->reestablish_timeout <<= 1;
 438                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 439                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 440                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 441                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 442         } else {
 443                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 444                 if (!RPC_IS_ASYNC(task))
 445                         flush_delayed_work(&r_xprt->rx_connect_worker);
 446         }
 447 }
 448
 449 /*
 450  * The RDMA allocate/free functions need the task structure as a place
 451  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 452  * sequence.
 453  *
 454  * The RPC layer allocates both send and receive buffers in the same call
 455  * (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
 456  * We may register rq_rcv_buf when using reply chunks.
 457  */
 458 static void *
 459 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 460 {
 461         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
 462         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 463         struct rpcrdma_regbuf *rb;
 464         struct rpcrdma_req *req;
 465         size_t min_size;
 466         gfp_t flags;
 467
 468         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 469         if (req == NULL)
 470                 return NULL;
 471
 472         flags = GFP_NOIO | __GFP_NOWARN;
 473         if (RPC_IS_SWAPPER(task))
 474                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 475
 476         if (req->rl_rdmabuf == NULL)
 477                 goto out_rdmabuf;
 478         if (req->rl_sendbuf == NULL)
 479                 goto out_sendbuf;
 480         if (size > req->rl_sendbuf->rg_size)
 481                 goto out_sendbuf;
 482
 483 out:
 484         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 485         req->rl_connect_cookie = 0;     /* our reserved value */
 486         return req->rl_sendbuf->rg_base;
 487
 488 out_rdmabuf:
 489         min_size = RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 490         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, min_size, flags);
 491         if (IS_ERR(rb))
 492                 goto out_fail;
 493         req->rl_rdmabuf = rb;
 494
 495 out_sendbuf:
 496         /* XDR encoding and RPC/RDMA marshaling of this request has not
 497          * yet occurred. Thus a lower bound is needed to prevent buffer
 498          * overrun during marshaling.
 499          *
 500          * RPC/RDMA marshaling may choose to send payload bearing ops
 501          * inline, if the result is smaller than the inline threshold.
 502          * The value of the "size" argument accounts for header
 503          * requirements but not for the payload in these cases.
 504          *
 505          * Likewise, allocate enough space to receive a reply up to the
 506          * size of the inline threshold.
 507          *
 508          * It's unlikely that both the send header and the received
 509          * reply will be large, but slush is provided here to allow
 510          * flexibility when marshaling.
 511          */
 512         min_size = RPCRDMA_INLINE_READ_THRESHOLD(task->tk_rqstp);
 513         min_size += RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 514         if (size < min_size)
 515                 size = min_size;
 516
 517         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags);
 518         if (IS_ERR(rb))
 519                 goto out_fail;
 520         rb->rg_owner = req;
 521
 522         r_xprt->rx_stats.hardway_register_count += size;
 523         rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
 524         req->rl_sendbuf = rb;
 525         goto out;
 526
 527 out_fail:
 528         rpcrdma_buffer_put(req);
 529         r_xprt->rx_stats.failed_marshal_count++;
 530         return NULL;
 531 }
 532
 533 /*
 534  * This function returns all RDMA resources to the pool.
 535  */
 536 static void
 537 xprt_rdma_free(void *buffer)
 538 {
 539         struct rpcrdma_req *req;
 540         struct rpcrdma_xprt *r_xprt;
 541         struct rpcrdma_regbuf *rb;
 542         int i;
 543
 544         if (buffer == NULL)
 545                 return;
 546
 547         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
 548         req = rb->rg_owner;
 549         r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 550
 551         dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 552
 553         for (i = 0; req->rl_nchunks;) {
 554                 --req->rl_nchunks;
 555                 i += rpcrdma_deregister_external(
 556                         &req->rl_segments[i], r_xprt);
 557         }
 558
 559         rpcrdma_buffer_put(req);
 560 }
 561
 562 /*
 563  * send_request invokes the meat of RPC RDMA. It must do the following:
 564  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 565  *      putting a header in front of data, and creating IOVs for RDMA
 566  *      from those in the request.
 567  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 568  *  3.  Post a recv message to set up asynch completion, then send
 569  *      the request (rpcrdma_ep_post).
 570  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 571  */
 572
 573 static int
 574 xprt_rdma_send_request(struct rpc_task *task)
 575 {
 576         struct rpc_rqst *rqst = task->tk_rqstp;
 577         struct rpc_xprt *xprt = rqst->rq_xprt;
 578         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 579         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 580         int rc = 0;
 581
 582         if (req->rl_niovs == 0)
 583                 rc = rpcrdma_marshal_req(rqst);
 584         else if (r_xprt->rx_ia.ri_memreg_strategy != RPCRDMA_ALLPHYSICAL)
 585                 rc = rpcrdma_marshal_chunks(rqst, 0);
 586         if (rc < 0)
 587                 goto failed_marshal;
 588
 589         if (req->rl_reply == NULL)              /* e.g. reconnection */
 590                 rpcrdma_recv_buffer_get(req);
 591
 592         if (req->rl_reply) {
 593                 req->rl_reply->rr_func = rpcrdma_reply_handler;
 594                 /* this need only be done once, but... */
 595                 req->rl_reply->rr_xprt = xprt;
 596         }
 597
 598         /* Must suppress retransmit to maintain credits */
 599         if (req->rl_connect_cookie == xprt->connect_cookie)
 600                 goto drop_connection;
 601         req->rl_connect_cookie = xprt->connect_cookie;
 602
 603         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 604                 goto drop_connection;
 605
 606         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 607         rqst->rq_bytes_sent = 0;
 608         return 0;
 609
 610 failed_marshal:
 611         r_xprt->rx_stats.failed_marshal_count++;
 612         dprintk("RPC:       %s: rpcrdma_marshal_req failed, status %i\n",
 613                 __func__, rc);
 614         if (rc == -EIO)
 615                 return -EIO;
 616 drop_connection:
 617         xprt_disconnect_done(xprt);
 618         return -ENOTCONN;       /* implies disconnect */
 619 }
 620
 621 static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 622 {
 623         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 624         long idle_time = 0;
 625
 626         if (xprt_connected(xprt))
 627                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 628
 629         seq_printf(seq,
 630           "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
 631           "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
 632
 633            0,   /* need a local port? */
 634            xprt->stat.bind_count,
 635            xprt->stat.connect_count,
 636            xprt->stat.connect_time,
 637            idle_time,
 638            xprt->stat.sends,
 639            xprt->stat.recvs,
 640            xprt->stat.bad_xids,
 641            xprt->stat.req_u,
 642            xprt->stat.bklog_u,
 643
 644            r_xprt->rx_stats.read_chunk_count,
 645            r_xprt->rx_stats.write_chunk_count,
 646            r_xprt->rx_stats.reply_chunk_count,
 647            r_xprt->rx_stats.total_rdma_request,
 648            r_xprt->rx_stats.total_rdma_reply,
 649            r_xprt->rx_stats.pullup_copy_count,
 650            r_xprt->rx_stats.fixup_copy_count,
 651            r_xprt->rx_stats.hardway_register_count,
 652            r_xprt->rx_stats.failed_marshal_count,
 653            r_xprt->rx_stats.bad_reply_count);
 654 }
 655
 656 /*
 657  * Plumbing for rpc transport switch and kernel module
 658  */
 659
 660 static struct rpc_xprt_ops xprt_rdma_procs = {
 661         .reserve_xprt           = xprt_reserve_xprt_cong,
 662         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 663         .alloc_slot             = xprt_alloc_slot,
 664         .release_request        = xprt_release_rqst_cong,       /* ditto */
 665         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 666         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 667         .set_port               = xprt_rdma_set_port,
 668         .connect                = xprt_rdma_connect,
 669         .buf_alloc              = xprt_rdma_allocate,
 670         .buf_free               = xprt_rdma_free,
 671         .send_request           = xprt_rdma_send_request,
 672         .close                  = xprt_rdma_close,
 673         .destroy                = xprt_rdma_destroy,
 674         .print_stats            = xprt_rdma_print_stats
 675 };
 676
 677 static struct xprt_class xprt_rdma = {
 678         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 679         .name                   = "rdma",
 680         .owner                  = THIS_MODULE,
 681         .ident                  = XPRT_TRANSPORT_RDMA,
 682         .setup                  = xprt_setup_rdma,
 683 };
 684
 685 static void __exit xprt_rdma_cleanup(void)
 686 {
 687         int rc;
 688
 689         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 690 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 691         if (sunrpc_table_header) {
 692                 unregister_sysctl_table(sunrpc_table_header);
 693                 sunrpc_table_header = NULL;
 694         }
 695 #endif
 696         rc = xprt_unregister_transport(&xprt_rdma);
 697         if (rc)
 698                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 699                         __func__, rc);
 700 }
 701
 702 static int __init xprt_rdma_init(void)
 703 {
 704         int rc;
 705
 706         rc = xprt_register_transport(&xprt_rdma);
 707
 708         if (rc)
 709                 return rc;
 710
 711         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 712
 713         dprintk("Defaults:\n");
 714         dprintk("\tSlots %d\n"
 715                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 716                 xprt_rdma_slot_table_entries,
 717                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 718         dprintk("\tPadding %d\n\tMemreg %d\n",
 719                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 720
 721 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 722         if (!sunrpc_table_header)
 723                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 724 #endif
 725         return 0;
 726 }
 727
 728 module_init(xprt_rdma_init);
 729 module_exit(xprt_rdma_cleanup);