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_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 161 {
 162         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 163         char buf[20];
 164
 165         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 166         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 167
 168         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 169 }
 170
 171 static void
 172 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 173 {
 174         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 175         char buf[40];
 176
 177         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 178         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 179
 180         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 181 }
 182
 183 static void
 184 xprt_rdma_format_addresses(struct rpc_xprt *xprt)
 185 {
 186         struct sockaddr *sap = (struct sockaddr *)
 187                                         &rpcx_to_rdmad(xprt).addr;
 188         char buf[128];
 189
 190         switch (sap->sa_family) {
 191         case AF_INET:
 192                 xprt_rdma_format_addresses4(xprt, sap);
 193                 break;
 194         case AF_INET6:
 195                 xprt_rdma_format_addresses6(xprt, sap);
 196                 break;
 197         default:
 198                 pr_err("rpcrdma: Unrecognized address family\n");
 199                 return;
 200         }
 201
 202         (void)rpc_ntop(sap, buf, sizeof(buf));
 203         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 204
 205         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 206         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 207
 208         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 209         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 210
 211         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 212 }
 213
 214 static void
 215 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 216 {
 217         unsigned int i;
 218
 219         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 220                 switch (i) {
 221                 case RPC_DISPLAY_PROTO:
 222                 case RPC_DISPLAY_NETID:
 223                         continue;
 224                 default:
 225                         kfree(xprt->address_strings[i]);
 226                 }
 227 }
 228
 229 static void
 230 xprt_rdma_connect_worker(struct work_struct *work)
 231 {
 232         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 233                                                    rx_connect_worker.work);
 234         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 235         int rc = 0;
 236
 237         xprt_clear_connected(xprt);
 238
 239         dprintk("RPC:       %s: %sconnect\n", __func__,
 240                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 241         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 242         if (rc)
 243                 xprt_wake_pending_tasks(xprt, rc);
 244
 245         dprintk("RPC:       %s: exit\n", __func__);
 246         xprt_clear_connecting(xprt);
 247 }
 248
 249 /*
 250  * xprt_rdma_destroy
 251  *
 252  * Destroy the xprt.
 253  * Free all memory associated with the object, including its own.
 254  * NOTE: none of the *destroy methods free memory for their top-level
 255  * objects, even though they may have allocated it (they do free
 256  * private memory). It's up to the caller to handle it. In this
 257  * case (RDMA transport), all structure memory is inlined with the
 258  * struct rpcrdma_xprt.
 259  */
 260 static void
 261 xprt_rdma_destroy(struct rpc_xprt *xprt)
 262 {
 263         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 264
 265         dprintk("RPC:       %s: called\n", __func__);
 266
 267         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 268
 269         xprt_clear_connected(xprt);
 270
 271         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 272         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 273         rpcrdma_ia_close(&r_xprt->rx_ia);
 274
 275         xprt_rdma_free_addresses(xprt);
 276
 277         xprt_free(xprt);
 278
 279         dprintk("RPC:       %s: returning\n", __func__);
 280
 281         module_put(THIS_MODULE);
 282 }
 283
 284 static const struct rpc_timeout xprt_rdma_default_timeout = {
 285         .to_initval = 60 * HZ,
 286         .to_maxval = 60 * HZ,
 287 };
 288
 289 /**
 290  * xprt_setup_rdma - Set up transport to use RDMA
 291  *
 292  * @args: rpc transport arguments
 293  */
 294 static struct rpc_xprt *
 295 xprt_setup_rdma(struct xprt_create *args)
 296 {
 297         struct rpcrdma_create_data_internal cdata;
 298         struct rpc_xprt *xprt;
 299         struct rpcrdma_xprt *new_xprt;
 300         struct rpcrdma_ep *new_ep;
 301         struct sockaddr_in *sin;
 302         int rc;
 303
 304         if (args->addrlen > sizeof(xprt->addr)) {
 305                 dprintk("RPC:       %s: address too large\n", __func__);
 306                 return ERR_PTR(-EBADF);
 307         }
 308
 309         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 310                         xprt_rdma_slot_table_entries,
 311                         xprt_rdma_slot_table_entries);
 312         if (xprt == NULL) {
 313                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 314                         __func__);
 315                 return ERR_PTR(-ENOMEM);
 316         }
 317
 318         /* 60 second timeout, no retries */
 319         xprt->timeout = &xprt_rdma_default_timeout;
 320         xprt->bind_timeout = RPCRDMA_BIND_TO;
 321         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 322         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 323
 324         xprt->resvport = 0;             /* privileged port not needed */
 325         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 326         xprt->ops = &xprt_rdma_procs;
 327
 328         /*
 329          * Set up RDMA-specific connect data.
 330          */
 331
 332         /* Put server RDMA address in local cdata */
 333         memcpy(&cdata.addr, args->dstaddr, args->addrlen);
 334
 335         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 336          * address, for any side protocols which peek at it */
 337         xprt->prot = IPPROTO_TCP;
 338         xprt->addrlen = args->addrlen;
 339         memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
 340
 341         sin = (struct sockaddr_in *)&cdata.addr;
 342         if (ntohs(sin->sin_port) != 0)
 343                 xprt_set_bound(xprt);
 344
 345         dprintk("RPC:       %s: %pI4:%u\n",
 346                 __func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
 347
 348         /* Set max requests */
 349         cdata.max_requests = xprt->max_reqs;
 350
 351         /* Set some length limits */
 352         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 353         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 354
 355         cdata.inline_wsize = xprt_rdma_max_inline_write;
 356         if (cdata.inline_wsize > cdata.wsize)
 357                 cdata.inline_wsize = cdata.wsize;
 358
 359         cdata.inline_rsize = xprt_rdma_max_inline_read;
 360         if (cdata.inline_rsize > cdata.rsize)
 361                 cdata.inline_rsize = cdata.rsize;
 362
 363         cdata.padding = xprt_rdma_inline_write_padding;
 364
 365         /*
 366          * Create new transport instance, which includes initialized
 367          *  o ia
 368          *  o endpoint
 369          *  o buffers
 370          */
 371
 372         new_xprt = rpcx_to_rdmax(xprt);
 373
 374         rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
 375                                 xprt_rdma_memreg_strategy);
 376         if (rc)
 377                 goto out1;
 378
 379         /*
 380          * initialize and create ep
 381          */
 382         new_xprt->rx_data = cdata;
 383         new_ep = &new_xprt->rx_ep;
 384         new_ep->rep_remote_addr = cdata.addr;
 385
 386         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 387                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 388         if (rc)
 389                 goto out2;
 390
 391         /*
 392          * Allocate pre-registered send and receive buffers for headers and
 393          * any inline data. Also specify any padding which will be provided
 394          * from a preregistered zero buffer.
 395          */
 396         rc = rpcrdma_buffer_create(new_xprt);
 397         if (rc)
 398                 goto out3;
 399
 400         /*
 401          * Register a callback for connection events. This is necessary because
 402          * connection loss notification is async. We also catch connection loss
 403          * when reaping receives.
 404          */
 405         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 406                           xprt_rdma_connect_worker);
 407
 408         xprt_rdma_format_addresses(xprt);
 409         xprt->max_payload = rpcrdma_max_payload(new_xprt);
 410         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 411                 __func__, xprt->max_payload);
 412
 413         if (!try_module_get(THIS_MODULE))
 414                 goto out4;
 415
 416         return xprt;
 417
 418 out4:
 419         xprt_rdma_free_addresses(xprt);
 420         rc = -EINVAL;
 421 out3:
 422         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 423 out2:
 424         rpcrdma_ia_close(&new_xprt->rx_ia);
 425 out1:
 426         xprt_free(xprt);
 427         return ERR_PTR(rc);
 428 }
 429
 430 /*
 431  * Close a connection, during shutdown or timeout/reconnect
 432  */
 433 static void
 434 xprt_rdma_close(struct rpc_xprt *xprt)
 435 {
 436         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 437
 438         dprintk("RPC:       %s: closing\n", __func__);
 439         if (r_xprt->rx_ep.rep_connected > 0)
 440                 xprt->reestablish_timeout = 0;
 441         xprt_disconnect_done(xprt);
 442         rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 443 }
 444
 445 static void
 446 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 447 {
 448         struct sockaddr_in *sap;
 449
 450         sap = (struct sockaddr_in *)&xprt->addr;
 451         sap->sin_port = htons(port);
 452         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 453         sap->sin_port = htons(port);
 454         dprintk("RPC:       %s: %u\n", __func__, port);
 455 }
 456
 457 static void
 458 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 459 {
 460         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 461
 462         if (r_xprt->rx_ep.rep_connected != 0) {
 463                 /* Reconnect */
 464                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 465                                       xprt->reestablish_timeout);
 466                 xprt->reestablish_timeout <<= 1;
 467                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 468                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 469                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 470                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 471         } else {
 472                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 473                 if (!RPC_IS_ASYNC(task))
 474                         flush_delayed_work(&r_xprt->rx_connect_worker);
 475         }
 476 }
 477
 478 /*
 479  * The RDMA allocate/free functions need the task structure as a place
 480  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 481  * sequence.
 482  *
 483  * The RPC layer allocates both send and receive buffers in the same call
 484  * (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
 485  * We may register rq_rcv_buf when using reply chunks.
 486  */
 487 static void *
 488 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 489 {
 490         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
 491         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 492         struct rpcrdma_regbuf *rb;
 493         struct rpcrdma_req *req;
 494         size_t min_size;
 495         gfp_t flags;
 496
 497         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 498         if (req == NULL)
 499                 return NULL;
 500
 501         flags = GFP_NOIO | __GFP_NOWARN;
 502         if (RPC_IS_SWAPPER(task))
 503                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 504
 505         if (req->rl_rdmabuf == NULL)
 506                 goto out_rdmabuf;
 507         if (req->rl_sendbuf == NULL)
 508                 goto out_sendbuf;
 509         if (size > req->rl_sendbuf->rg_size)
 510                 goto out_sendbuf;
 511
 512 out:
 513         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 514         req->rl_connect_cookie = 0;     /* our reserved value */
 515         return req->rl_sendbuf->rg_base;
 516
 517 out_rdmabuf:
 518         min_size = RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 519         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, min_size, flags);
 520         if (IS_ERR(rb))
 521                 goto out_fail;
 522         req->rl_rdmabuf = rb;
 523
 524 out_sendbuf:
 525         /* XDR encoding and RPC/RDMA marshaling of this request has not
 526          * yet occurred. Thus a lower bound is needed to prevent buffer
 527          * overrun during marshaling.
 528          *
 529          * RPC/RDMA marshaling may choose to send payload bearing ops
 530          * inline, if the result is smaller than the inline threshold.
 531          * The value of the "size" argument accounts for header
 532          * requirements but not for the payload in these cases.
 533          *
 534          * Likewise, allocate enough space to receive a reply up to the
 535          * size of the inline threshold.
 536          *
 537          * It's unlikely that both the send header and the received
 538          * reply will be large, but slush is provided here to allow
 539          * flexibility when marshaling.
 540          */
 541         min_size = RPCRDMA_INLINE_READ_THRESHOLD(task->tk_rqstp);
 542         min_size += RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
 543         if (size < min_size)
 544                 size = min_size;
 545
 546         rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags);
 547         if (IS_ERR(rb))
 548                 goto out_fail;
 549         rb->rg_owner = req;
 550
 551         r_xprt->rx_stats.hardway_register_count += size;
 552         rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
 553         req->rl_sendbuf = rb;
 554         goto out;
 555
 556 out_fail:
 557         rpcrdma_buffer_put(req);
 558         r_xprt->rx_stats.failed_marshal_count++;
 559         return NULL;
 560 }
 561
 562 /*
 563  * This function returns all RDMA resources to the pool.
 564  */
 565 static void
 566 xprt_rdma_free(void *buffer)
 567 {
 568         struct rpcrdma_req *req;
 569         struct rpcrdma_xprt *r_xprt;
 570         struct rpcrdma_regbuf *rb;
 571         int i;
 572
 573         if (buffer == NULL)
 574                 return;
 575
 576         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
 577         req = rb->rg_owner;
 578         r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 579
 580         dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 581
 582         for (i = 0; req->rl_nchunks;) {
 583                 --req->rl_nchunks;
 584                 i += rpcrdma_deregister_external(
 585                         &req->rl_segments[i], r_xprt);
 586         }
 587
 588         rpcrdma_buffer_put(req);
 589 }
 590
 591 /*
 592  * send_request invokes the meat of RPC RDMA. It must do the following:
 593  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 594  *      putting a header in front of data, and creating IOVs for RDMA
 595  *      from those in the request.
 596  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 597  *  3.  Post a recv message to set up asynch completion, then send
 598  *      the request (rpcrdma_ep_post).
 599  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 600  */
 601
 602 static int
 603 xprt_rdma_send_request(struct rpc_task *task)
 604 {
 605         struct rpc_rqst *rqst = task->tk_rqstp;
 606         struct rpc_xprt *xprt = rqst->rq_xprt;
 607         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 608         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 609         int rc = 0;
 610
 611         rc = rpcrdma_marshal_req(rqst);
 612         if (rc < 0)
 613                 goto failed_marshal;
 614
 615         if (req->rl_reply == NULL)              /* e.g. reconnection */
 616                 rpcrdma_recv_buffer_get(req);
 617
 618         if (req->rl_reply) {
 619                 req->rl_reply->rr_func = rpcrdma_reply_handler;
 620                 /* this need only be done once, but... */
 621                 req->rl_reply->rr_xprt = xprt;
 622         }
 623
 624         /* Must suppress retransmit to maintain credits */
 625         if (req->rl_connect_cookie == xprt->connect_cookie)
 626                 goto drop_connection;
 627         req->rl_connect_cookie = xprt->connect_cookie;
 628
 629         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 630                 goto drop_connection;
 631
 632         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 633         rqst->rq_bytes_sent = 0;
 634         return 0;
 635
 636 failed_marshal:
 637         r_xprt->rx_stats.failed_marshal_count++;
 638         dprintk("RPC:       %s: rpcrdma_marshal_req failed, status %i\n",
 639                 __func__, rc);
 640         if (rc == -EIO)
 641                 return -EIO;
 642 drop_connection:
 643         xprt_disconnect_done(xprt);
 644         return -ENOTCONN;       /* implies disconnect */
 645 }
 646
 647 static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 648 {
 649         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 650         long idle_time = 0;
 651
 652         if (xprt_connected(xprt))
 653                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 654
 655         seq_printf(seq,
 656           "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
 657           "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
 658
 659            0,   /* need a local port? */
 660            xprt->stat.bind_count,
 661            xprt->stat.connect_count,
 662            xprt->stat.connect_time,
 663            idle_time,
 664            xprt->stat.sends,
 665            xprt->stat.recvs,
 666            xprt->stat.bad_xids,
 667            xprt->stat.req_u,
 668            xprt->stat.bklog_u,
 669
 670            r_xprt->rx_stats.read_chunk_count,
 671            r_xprt->rx_stats.write_chunk_count,
 672            r_xprt->rx_stats.reply_chunk_count,
 673            r_xprt->rx_stats.total_rdma_request,
 674            r_xprt->rx_stats.total_rdma_reply,
 675            r_xprt->rx_stats.pullup_copy_count,
 676            r_xprt->rx_stats.fixup_copy_count,
 677            r_xprt->rx_stats.hardway_register_count,
 678            r_xprt->rx_stats.failed_marshal_count,
 679            r_xprt->rx_stats.bad_reply_count);
 680 }
 681
 682 /*
 683  * Plumbing for rpc transport switch and kernel module
 684  */
 685
 686 static struct rpc_xprt_ops xprt_rdma_procs = {
 687         .reserve_xprt           = xprt_reserve_xprt_cong,
 688         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 689         .alloc_slot             = xprt_alloc_slot,
 690         .release_request        = xprt_release_rqst_cong,       /* ditto */
 691         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 692         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 693         .set_port               = xprt_rdma_set_port,
 694         .connect                = xprt_rdma_connect,
 695         .buf_alloc              = xprt_rdma_allocate,
 696         .buf_free               = xprt_rdma_free,
 697         .send_request           = xprt_rdma_send_request,
 698         .close                  = xprt_rdma_close,
 699         .destroy                = xprt_rdma_destroy,
 700         .print_stats            = xprt_rdma_print_stats
 701 };
 702
 703 static struct xprt_class xprt_rdma = {
 704         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 705         .name                   = "rdma",
 706         .owner                  = THIS_MODULE,
 707         .ident                  = XPRT_TRANSPORT_RDMA,
 708         .setup                  = xprt_setup_rdma,
 709 };
 710
 711 static void __exit xprt_rdma_cleanup(void)
 712 {
 713         int rc;
 714
 715         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 716 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 717         if (sunrpc_table_header) {
 718                 unregister_sysctl_table(sunrpc_table_header);
 719                 sunrpc_table_header = NULL;
 720         }
 721 #endif
 722         rc = xprt_unregister_transport(&xprt_rdma);
 723         if (rc)
 724                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 725                         __func__, rc);
 726 }
 727
 728 static int __init xprt_rdma_init(void)
 729 {
 730         int rc;
 731
 732         rc = xprt_register_transport(&xprt_rdma);
 733
 734         if (rc)
 735                 return rc;
 736
 737         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 738
 739         dprintk("Defaults:\n");
 740         dprintk("\tSlots %d\n"
 741                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 742                 xprt_rdma_slot_table_entries,
 743                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 744         dprintk("\tPadding %d\n\tMemreg %d\n",
 745                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 746
 747 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 748         if (!sunrpc_table_header)
 749                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 750 #endif
 751         return 0;
 752 }
 753
 754 module_init(xprt_rdma_init);
 755 module_exit(xprt_rdma_cleanup);