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 #ifdef RPC_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 = 0;
  77
  78 #ifdef RPC_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 static struct rpc_xprt_ops xprt_rdma_procs;     /* forward reference */
 153
 154 static void
 155 xprt_rdma_format_addresses(struct rpc_xprt *xprt)
 156 {
 157         struct sockaddr *sap = (struct sockaddr *)
 158                                         &rpcx_to_rdmad(xprt).addr;
 159         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 160         char buf[64];
 161
 162         (void)rpc_ntop(sap, buf, sizeof(buf));
 163         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 164
 165         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 166         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 167
 168         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 169
 170         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 171         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 172
 173         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 174         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 175
 176         /* netid */
 177         xprt->address_strings[RPC_DISPLAY_NETID] = "rdma";
 178 }
 179
 180 static void
 181 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 182 {
 183         unsigned int i;
 184
 185         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 186                 switch (i) {
 187                 case RPC_DISPLAY_PROTO:
 188                 case RPC_DISPLAY_NETID:
 189                         continue;
 190                 default:
 191                         kfree(xprt->address_strings[i]);
 192                 }
 193 }
 194
 195 static void
 196 xprt_rdma_connect_worker(struct work_struct *work)
 197 {
 198         struct rpcrdma_xprt *r_xprt =
 199                 container_of(work, struct rpcrdma_xprt, rdma_connect.work);
 200         struct rpc_xprt *xprt = &r_xprt->xprt;
 201         int rc = 0;
 202
 203         current->flags |= PF_FSTRANS;
 204         xprt_clear_connected(xprt);
 205
 206         dprintk("RPC:       %s: %sconnect\n", __func__,
 207                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 208         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 209         if (rc)
 210                 xprt_wake_pending_tasks(xprt, rc);
 211
 212         dprintk("RPC:       %s: exit\n", __func__);
 213         xprt_clear_connecting(xprt);
 214         current->flags &= ~PF_FSTRANS;
 215 }
 216
 217 /*
 218  * xprt_rdma_destroy
 219  *
 220  * Destroy the xprt.
 221  * Free all memory associated with the object, including its own.
 222  * NOTE: none of the *destroy methods free memory for their top-level
 223  * objects, even though they may have allocated it (they do free
 224  * private memory). It's up to the caller to handle it. In this
 225  * case (RDMA transport), all structure memory is inlined with the
 226  * struct rpcrdma_xprt.
 227  */
 228 static void
 229 xprt_rdma_destroy(struct rpc_xprt *xprt)
 230 {
 231         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 232         int rc;
 233
 234         dprintk("RPC:       %s: called\n", __func__);
 235
 236         cancel_delayed_work_sync(&r_xprt->rdma_connect);
 237
 238         xprt_clear_connected(xprt);
 239
 240         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 241         rc = rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 242         if (rc)
 243                 dprintk("RPC:       %s: rpcrdma_ep_destroy returned %i\n",
 244                         __func__, rc);
 245         rpcrdma_ia_close(&r_xprt->rx_ia);
 246
 247         xprt_rdma_free_addresses(xprt);
 248
 249         xprt_free(xprt);
 250
 251         dprintk("RPC:       %s: returning\n", __func__);
 252
 253         module_put(THIS_MODULE);
 254 }
 255
 256 static const struct rpc_timeout xprt_rdma_default_timeout = {
 257         .to_initval = 60 * HZ,
 258         .to_maxval = 60 * HZ,
 259 };
 260
 261 /**
 262  * xprt_setup_rdma - Set up transport to use RDMA
 263  *
 264  * @args: rpc transport arguments
 265  */
 266 static struct rpc_xprt *
 267 xprt_setup_rdma(struct xprt_create *args)
 268 {
 269         struct rpcrdma_create_data_internal cdata;
 270         struct rpc_xprt *xprt;
 271         struct rpcrdma_xprt *new_xprt;
 272         struct rpcrdma_ep *new_ep;
 273         struct sockaddr_in *sin;
 274         int rc;
 275
 276         if (args->addrlen > sizeof(xprt->addr)) {
 277                 dprintk("RPC:       %s: address too large\n", __func__);
 278                 return ERR_PTR(-EBADF);
 279         }
 280
 281         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 282                         xprt_rdma_slot_table_entries,
 283                         xprt_rdma_slot_table_entries);
 284         if (xprt == NULL) {
 285                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 286                         __func__);
 287                 return ERR_PTR(-ENOMEM);
 288         }
 289
 290         /* 60 second timeout, no retries */
 291         xprt->timeout = &xprt_rdma_default_timeout;
 292         xprt->bind_timeout = (60U * HZ);
 293         xprt->reestablish_timeout = (5U * HZ);
 294         xprt->idle_timeout = (5U * 60 * HZ);
 295
 296         xprt->resvport = 0;             /* privileged port not needed */
 297         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 298         xprt->max_payload = RPCRDMA_MAX_DATA_SEGS * PAGE_SIZE;
 299         xprt->ops = &xprt_rdma_procs;
 300
 301         /*
 302          * Set up RDMA-specific connect data.
 303          */
 304
 305         /* Put server RDMA address in local cdata */
 306         memcpy(&cdata.addr, args->dstaddr, args->addrlen);
 307
 308         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 309          * address, for any side protocols which peek at it */
 310         xprt->prot = IPPROTO_TCP;
 311         xprt->addrlen = args->addrlen;
 312         memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
 313
 314         sin = (struct sockaddr_in *)&cdata.addr;
 315         if (ntohs(sin->sin_port) != 0)
 316                 xprt_set_bound(xprt);
 317
 318         dprintk("RPC:       %s: %pI4:%u\n",
 319                 __func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
 320
 321         /* Set max requests */
 322         cdata.max_requests = xprt->max_reqs;
 323
 324         /* Set some length limits */
 325         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 326         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 327
 328         cdata.inline_wsize = xprt_rdma_max_inline_write;
 329         if (cdata.inline_wsize > cdata.wsize)
 330                 cdata.inline_wsize = cdata.wsize;
 331
 332         cdata.inline_rsize = xprt_rdma_max_inline_read;
 333         if (cdata.inline_rsize > cdata.rsize)
 334                 cdata.inline_rsize = cdata.rsize;
 335
 336         cdata.padding = xprt_rdma_inline_write_padding;
 337
 338         /*
 339          * Create new transport instance, which includes initialized
 340          *  o ia
 341          *  o endpoint
 342          *  o buffers
 343          */
 344
 345         new_xprt = rpcx_to_rdmax(xprt);
 346
 347         rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
 348                                 xprt_rdma_memreg_strategy);
 349         if (rc)
 350                 goto out1;
 351
 352         /*
 353          * initialize and create ep
 354          */
 355         new_xprt->rx_data = cdata;
 356         new_ep = &new_xprt->rx_ep;
 357         new_ep->rep_remote_addr = cdata.addr;
 358
 359         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 360                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 361         if (rc)
 362                 goto out2;
 363
 364         /*
 365          * Allocate pre-registered send and receive buffers for headers and
 366          * any inline data. Also specify any padding which will be provided
 367          * from a preregistered zero buffer.
 368          */
 369         rc = rpcrdma_buffer_create(&new_xprt->rx_buf, new_ep, &new_xprt->rx_ia,
 370                                 &new_xprt->rx_data);
 371         if (rc)
 372                 goto out3;
 373
 374         /*
 375          * Register a callback for connection events. This is necessary because
 376          * connection loss notification is async. We also catch connection loss
 377          * when reaping receives.
 378          */
 379         INIT_DELAYED_WORK(&new_xprt->rdma_connect, xprt_rdma_connect_worker);
 380         new_ep->rep_func = rpcrdma_conn_func;
 381         new_ep->rep_xprt = xprt;
 382
 383         xprt_rdma_format_addresses(xprt);
 384
 385         if (!try_module_get(THIS_MODULE))
 386                 goto out4;
 387
 388         return xprt;
 389
 390 out4:
 391         xprt_rdma_free_addresses(xprt);
 392         rc = -EINVAL;
 393 out3:
 394         (void) rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 395 out2:
 396         rpcrdma_ia_close(&new_xprt->rx_ia);
 397 out1:
 398         xprt_free(xprt);
 399         return ERR_PTR(rc);
 400 }
 401
 402 /*
 403  * Close a connection, during shutdown or timeout/reconnect
 404  */
 405 static void
 406 xprt_rdma_close(struct rpc_xprt *xprt)
 407 {
 408         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 409
 410         dprintk("RPC:       %s: closing\n", __func__);
 411         if (r_xprt->rx_ep.rep_connected > 0)
 412                 xprt->reestablish_timeout = 0;
 413         xprt_disconnect_done(xprt);
 414         (void) rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 415 }
 416
 417 static void
 418 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 419 {
 420         struct sockaddr_in *sap;
 421
 422         sap = (struct sockaddr_in *)&xprt->addr;
 423         sap->sin_port = htons(port);
 424         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 425         sap->sin_port = htons(port);
 426         dprintk("RPC:       %s: %u\n", __func__, port);
 427 }
 428
 429 static void
 430 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 431 {
 432         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 433
 434         if (r_xprt->rx_ep.rep_connected != 0) {
 435                 /* Reconnect */
 436                 schedule_delayed_work(&r_xprt->rdma_connect,
 437                         xprt->reestablish_timeout);
 438                 xprt->reestablish_timeout <<= 1;
 439                 if (xprt->reestablish_timeout > (30 * HZ))
 440                         xprt->reestablish_timeout = (30 * HZ);
 441                 else if (xprt->reestablish_timeout < (5 * HZ))
 442                         xprt->reestablish_timeout = (5 * HZ);
 443         } else {
 444                 schedule_delayed_work(&r_xprt->rdma_connect, 0);
 445                 if (!RPC_IS_ASYNC(task))
 446                         flush_delayed_work(&r_xprt->rdma_connect);
 447         }
 448 }
 449
 450 static int
 451 xprt_rdma_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 452 {
 453         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 454         int credits = atomic_read(&r_xprt->rx_buf.rb_credits);
 455
 456         /* == RPC_CWNDSCALE @ init, but *after* setup */
 457         if (r_xprt->rx_buf.rb_cwndscale == 0UL) {
 458                 r_xprt->rx_buf.rb_cwndscale = xprt->cwnd;
 459                 dprintk("RPC:       %s: cwndscale %lu\n", __func__,
 460                         r_xprt->rx_buf.rb_cwndscale);
 461                 BUG_ON(r_xprt->rx_buf.rb_cwndscale <= 0);
 462         }
 463         xprt->cwnd = credits * r_xprt->rx_buf.rb_cwndscale;
 464         return xprt_reserve_xprt_cong(xprt, task);
 465 }
 466
 467 /*
 468  * The RDMA allocate/free functions need the task structure as a place
 469  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
 470  * sequence. For this reason, the recv buffers are attached to send
 471  * buffers for portions of the RPC. Note that the RPC layer allocates
 472  * both send and receive buffers in the same call. We may register
 473  * the receive buffer portion when using reply chunks.
 474  */
 475 static void *
 476 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 477 {
 478         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
 479         struct rpcrdma_req *req, *nreq;
 480
 481         req = rpcrdma_buffer_get(&rpcx_to_rdmax(xprt)->rx_buf);
 482         BUG_ON(NULL == req);
 483
 484         if (size > req->rl_size) {
 485                 dprintk("RPC:       %s: size %zd too large for buffer[%zd]: "
 486                         "prog %d vers %d proc %d\n",
 487                         __func__, size, req->rl_size,
 488                         task->tk_client->cl_prog, task->tk_client->cl_vers,
 489                         task->tk_msg.rpc_proc->p_proc);
 490                 /*
 491                  * Outgoing length shortage. Our inline write max must have
 492                  * been configured to perform direct i/o.
 493                  *
 494                  * This is therefore a large metadata operation, and the
 495                  * allocate call was made on the maximum possible message,
 496                  * e.g. containing long filename(s) or symlink data. In
 497                  * fact, while these metadata operations *might* carry
 498                  * large outgoing payloads, they rarely *do*. However, we
 499                  * have to commit to the request here, so reallocate and
 500                  * register it now. The data path will never require this
 501                  * reallocation.
 502                  *
 503                  * If the allocation or registration fails, the RPC framework
 504                  * will (doggedly) retry.
 505                  */
 506                 if (rpcx_to_rdmax(xprt)->rx_ia.ri_memreg_strategy ==
 507                                 RPCRDMA_BOUNCEBUFFERS) {
 508                         /* forced to "pure inline" */
 509                         dprintk("RPC:       %s: too much data (%zd) for inline "
 510                                         "(r/w max %d/%d)\n", __func__, size,
 511                                         rpcx_to_rdmad(xprt).inline_rsize,
 512                                         rpcx_to_rdmad(xprt).inline_wsize);
 513                         size = req->rl_size;
 514                         rpc_exit(task, -EIO);           /* fail the operation */
 515                         rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
 516                         goto out;
 517                 }
 518                 if (task->tk_flags & RPC_TASK_SWAPPER)
 519                         nreq = kmalloc(sizeof *req + size, GFP_ATOMIC);
 520                 else
 521                         nreq = kmalloc(sizeof *req + size, GFP_NOFS);
 522                 if (nreq == NULL)
 523                         goto outfail;
 524
 525                 if (rpcrdma_register_internal(&rpcx_to_rdmax(xprt)->rx_ia,
 526                                 nreq->rl_base, size + sizeof(struct rpcrdma_req)
 527                                 - offsetof(struct rpcrdma_req, rl_base),
 528                                 &nreq->rl_handle, &nreq->rl_iov)) {
 529                         kfree(nreq);
 530                         goto outfail;
 531                 }
 532                 rpcx_to_rdmax(xprt)->rx_stats.hardway_register_count += size;
 533                 nreq->rl_size = size;
 534                 nreq->rl_niovs = 0;
 535                 nreq->rl_nchunks = 0;
 536                 nreq->rl_buffer = (struct rpcrdma_buffer *)req;
 537                 nreq->rl_reply = req->rl_reply;
 538                 memcpy(nreq->rl_segments,
 539                         req->rl_segments, sizeof nreq->rl_segments);
 540                 /* flag the swap with an unused field */
 541                 nreq->rl_iov.length = 0;
 542                 req->rl_reply = NULL;
 543                 req = nreq;
 544         }
 545         dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 546 out:
 547         req->rl_connect_cookie = 0;     /* our reserved value */
 548         return req->rl_xdr_buf;
 549
 550 outfail:
 551         rpcrdma_buffer_put(req);
 552         rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
 553         return NULL;
 554 }
 555
 556 /*
 557  * This function returns all RDMA resources to the pool.
 558  */
 559 static void
 560 xprt_rdma_free(void *buffer)
 561 {
 562         struct rpcrdma_req *req;
 563         struct rpcrdma_xprt *r_xprt;
 564         struct rpcrdma_rep *rep;
 565         int i;
 566
 567         if (buffer == NULL)
 568                 return;
 569
 570         req = container_of(buffer, struct rpcrdma_req, rl_xdr_buf[0]);
 571         if (req->rl_iov.length == 0) {  /* see allocate above */
 572                 r_xprt = container_of(((struct rpcrdma_req *) req->rl_buffer)->rl_buffer,
 573                                       struct rpcrdma_xprt, rx_buf);
 574         } else
 575                 r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 576         rep = req->rl_reply;
 577
 578         dprintk("RPC:       %s: called on 0x%p%s\n",
 579                 __func__, rep, (rep && rep->rr_func) ? " (with waiter)" : "");
 580
 581         /*
 582          * Finish the deregistration. When using mw bind, this was
 583          * begun in rpcrdma_reply_handler(). In all other modes, we
 584          * do it here, in thread context. The process is considered
 585          * complete when the rr_func vector becomes NULL - this
 586          * was put in place during rpcrdma_reply_handler() - the wait
 587          * call below will not block if the dereg is "done". If
 588          * interrupted, our framework will clean up.
 589          */
 590         for (i = 0; req->rl_nchunks;) {
 591                 --req->rl_nchunks;
 592                 i += rpcrdma_deregister_external(
 593                         &req->rl_segments[i], r_xprt, NULL);
 594         }
 595
 596         if (rep && wait_event_interruptible(rep->rr_unbind, !rep->rr_func)) {
 597                 rep->rr_func = NULL;    /* abandon the callback */
 598                 req->rl_reply = NULL;
 599         }
 600
 601         if (req->rl_iov.length == 0) {  /* see allocate above */
 602                 struct rpcrdma_req *oreq = (struct rpcrdma_req *)req->rl_buffer;
 603                 oreq->rl_reply = req->rl_reply;
 604                 (void) rpcrdma_deregister_internal(&r_xprt->rx_ia,
 605                                                    req->rl_handle,
 606                                                    &req->rl_iov);
 607                 kfree(req);
 608                 req = oreq;
 609         }
 610
 611         /* Put back request+reply buffers */
 612         rpcrdma_buffer_put(req);
 613 }
 614
 615 /*
 616  * send_request invokes the meat of RPC RDMA. It must do the following:
 617  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 618  *      putting a header in front of data, and creating IOVs for RDMA
 619  *      from those in the request.
 620  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 621  *  3.  Post a recv message to set up asynch completion, then send
 622  *      the request (rpcrdma_ep_post).
 623  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 624  */
 625
 626 static int
 627 xprt_rdma_send_request(struct rpc_task *task)
 628 {
 629         struct rpc_rqst *rqst = task->tk_rqstp;
 630         struct rpc_xprt *xprt = rqst->rq_xprt;
 631         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 632         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 633
 634         /* marshal the send itself */
 635         if (req->rl_niovs == 0 && rpcrdma_marshal_req(rqst) != 0) {
 636                 r_xprt->rx_stats.failed_marshal_count++;
 637                 dprintk("RPC:       %s: rpcrdma_marshal_req failed\n",
 638                         __func__);
 639                 return -EIO;
 640         }
 641
 642         if (req->rl_reply == NULL)              /* e.g. reconnection */
 643                 rpcrdma_recv_buffer_get(req);
 644
 645         if (req->rl_reply) {
 646                 req->rl_reply->rr_func = rpcrdma_reply_handler;
 647                 /* this need only be done once, but... */
 648                 req->rl_reply->rr_xprt = xprt;
 649         }
 650
 651         /* Must suppress retransmit to maintain credits */
 652         if (req->rl_connect_cookie == xprt->connect_cookie)
 653                 goto drop_connection;
 654         req->rl_connect_cookie = xprt->connect_cookie;
 655
 656         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 657                 goto drop_connection;
 658
 659         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 660         rqst->rq_bytes_sent = 0;
 661         return 0;
 662
 663 drop_connection:
 664         xprt_disconnect_done(xprt);
 665         return -ENOTCONN;       /* implies disconnect */
 666 }
 667
 668 static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 669 {
 670         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 671         long idle_time = 0;
 672
 673         if (xprt_connected(xprt))
 674                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 675
 676         seq_printf(seq,
 677           "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
 678           "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
 679
 680            0,   /* need a local port? */
 681            xprt->stat.bind_count,
 682            xprt->stat.connect_count,
 683            xprt->stat.connect_time,
 684            idle_time,
 685            xprt->stat.sends,
 686            xprt->stat.recvs,
 687            xprt->stat.bad_xids,
 688            xprt->stat.req_u,
 689            xprt->stat.bklog_u,
 690
 691            r_xprt->rx_stats.read_chunk_count,
 692            r_xprt->rx_stats.write_chunk_count,
 693            r_xprt->rx_stats.reply_chunk_count,
 694            r_xprt->rx_stats.total_rdma_request,
 695            r_xprt->rx_stats.total_rdma_reply,
 696            r_xprt->rx_stats.pullup_copy_count,
 697            r_xprt->rx_stats.fixup_copy_count,
 698            r_xprt->rx_stats.hardway_register_count,
 699            r_xprt->rx_stats.failed_marshal_count,
 700            r_xprt->rx_stats.bad_reply_count);
 701 }
 702
 703 /*
 704  * Plumbing for rpc transport switch and kernel module
 705  */
 706
 707 static struct rpc_xprt_ops xprt_rdma_procs = {
 708         .reserve_xprt           = xprt_rdma_reserve_xprt,
 709         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 710         .alloc_slot             = xprt_alloc_slot,
 711         .release_request        = xprt_release_rqst_cong,       /* ditto */
 712         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 713         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 714         .set_port               = xprt_rdma_set_port,
 715         .connect                = xprt_rdma_connect,
 716         .buf_alloc              = xprt_rdma_allocate,
 717         .buf_free               = xprt_rdma_free,
 718         .send_request           = xprt_rdma_send_request,
 719         .close                  = xprt_rdma_close,
 720         .destroy                = xprt_rdma_destroy,
 721         .print_stats            = xprt_rdma_print_stats
 722 };
 723
 724 static struct xprt_class xprt_rdma = {
 725         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 726         .name                   = "rdma",
 727         .owner                  = THIS_MODULE,
 728         .ident                  = XPRT_TRANSPORT_RDMA,
 729         .setup                  = xprt_setup_rdma,
 730 };
 731
 732 static void __exit xprt_rdma_cleanup(void)
 733 {
 734         int rc;
 735
 736         dprintk(KERN_INFO "RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 737 #ifdef RPC_DEBUG
 738         if (sunrpc_table_header) {
 739                 unregister_sysctl_table(sunrpc_table_header);
 740                 sunrpc_table_header = NULL;
 741         }
 742 #endif
 743         rc = xprt_unregister_transport(&xprt_rdma);
 744         if (rc)
 745                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 746                         __func__, rc);
 747 }
 748
 749 static int __init xprt_rdma_init(void)
 750 {
 751         int rc;
 752
 753         rc = xprt_register_transport(&xprt_rdma);
 754
 755         if (rc)
 756                 return rc;
 757
 758         dprintk(KERN_INFO "RPCRDMA Module Init, register RPC RDMA transport\n");
 759
 760         dprintk(KERN_INFO "Defaults:\n");
 761         dprintk(KERN_INFO "\tSlots %d\n"
 762                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 763                 xprt_rdma_slot_table_entries,
 764                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 765         dprintk(KERN_INFO "\tPadding %d\n\tMemreg %d\n",
 766                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 767
 768 #ifdef RPC_DEBUG
 769         if (!sunrpc_table_header)
 770                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 771 #endif
 772         return 0;
 773 }
 774
 775 module_init(xprt_rdma_init);
 776 module_exit(xprt_rdma_cleanup);