net/sunrpc/xprtrdma/svc_rdma_sendto.c

   1 /*
   2  * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
   3  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the BSD-type
   9  * license below:
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  *
  15  *      Redistributions of source code must retain the above copyright
  16  *      notice, this list of conditions and the following disclaimer.
  17  *
  18  *      Redistributions in binary form must reproduce the above
  19  *      copyright notice, this list of conditions and the following
  20  *      disclaimer in the documentation and/or other materials provided
  21  *      with the distribution.
  22  *
  23  *      Neither the name of the Network Appliance, Inc. nor the names of
  24  *      its contributors may be used to endorse or promote products
  25  *      derived from this software without specific prior written
  26  *      permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  * Author: Tom Tucker <tom@opengridcomputing.com>
  41  */
  42
  43 #include <linux/sunrpc/debug.h>
  44 #include <linux/sunrpc/rpc_rdma.h>
  45 #include <linux/spinlock.h>
  46 #include <asm/unaligned.h>
  47 #include <rdma/ib_verbs.h>
  48 #include <rdma/rdma_cm.h>
  49 #include <linux/sunrpc/svc_rdma.h>
  50
  51 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
  52
  53 static int map_xdr(struct svcxprt_rdma *xprt,
  54                    struct xdr_buf *xdr,
  55                    struct svc_rdma_req_map *vec)
  56 {
  57         int sge_no;
  58         u32 sge_bytes;
  59         u32 page_bytes;
  60         u32 page_off;
  61         int page_no;
  62
  63         if (xdr->len !=
  64             (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len)) {
  65                 pr_err("svcrdma: map_xdr: XDR buffer length error\n");
  66                 return -EIO;
  67         }
  68
  69         /* Skip the first sge, this is for the RPCRDMA header */
  70         sge_no = 1;
  71
  72         /* Head SGE */
  73         vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
  74         vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
  75         sge_no++;
  76
  77         /* pages SGE */
  78         page_no = 0;
  79         page_bytes = xdr->page_len;
  80         page_off = xdr->page_base;
  81         while (page_bytes) {
  82                 vec->sge[sge_no].iov_base =
  83                         page_address(xdr->pages[page_no]) + page_off;
  84                 sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
  85                 page_bytes -= sge_bytes;
  86                 vec->sge[sge_no].iov_len = sge_bytes;
  87
  88                 sge_no++;
  89                 page_no++;
  90                 page_off = 0; /* reset for next time through loop */
  91         }
  92
  93         /* Tail SGE */
  94         if (xdr->tail[0].iov_len) {
  95                 vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
  96                 vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
  97                 sge_no++;
  98         }
  99
 100         dprintk("svcrdma: map_xdr: sge_no %d page_no %d "
 101                 "page_base %u page_len %u head_len %zu tail_len %zu\n",
 102                 sge_no, page_no, xdr->page_base, xdr->page_len,
 103                 xdr->head[0].iov_len, xdr->tail[0].iov_len);
 104
 105         vec->count = sge_no;
 106         return 0;
 107 }
 108
 109 static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt,
 110                               struct xdr_buf *xdr,
 111                               u32 xdr_off, size_t len, int dir)
 112 {
 113         struct page *page;
 114         dma_addr_t dma_addr;
 115         if (xdr_off < xdr->head[0].iov_len) {
 116                 /* This offset is in the head */
 117                 xdr_off += (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK;
 118                 page = virt_to_page(xdr->head[0].iov_base);
 119         } else {
 120                 xdr_off -= xdr->head[0].iov_len;
 121                 if (xdr_off < xdr->page_len) {
 122                         /* This offset is in the page list */
 123                         xdr_off += xdr->page_base;
 124                         page = xdr->pages[xdr_off >> PAGE_SHIFT];
 125                         xdr_off &= ~PAGE_MASK;
 126                 } else {
 127                         /* This offset is in the tail */
 128                         xdr_off -= xdr->page_len;
 129                         xdr_off += (unsigned long)
 130                                 xdr->tail[0].iov_base & ~PAGE_MASK;
 131                         page = virt_to_page(xdr->tail[0].iov_base);
 132                 }
 133         }
 134         dma_addr = ib_dma_map_page(xprt->sc_cm_id->device, page, xdr_off,
 135                                    min_t(size_t, PAGE_SIZE, len), dir);
 136         return dma_addr;
 137 }
 138
 139 /* Assumptions:
 140  * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
 141  */
 142 static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
 143                       u32 rmr, u64 to,
 144                       u32 xdr_off, int write_len,
 145                       struct svc_rdma_req_map *vec)
 146 {
 147         struct ib_send_wr write_wr;
 148         struct ib_sge *sge;
 149         int xdr_sge_no;
 150         int sge_no;
 151         int sge_bytes;
 152         int sge_off;
 153         int bc;
 154         struct svc_rdma_op_ctxt *ctxt;
 155
 156         if (vec->count > RPCSVC_MAXPAGES) {
 157                 pr_err("svcrdma: Too many pages (%lu)\n", vec->count);
 158                 return -EIO;
 159         }
 160
 161         dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
 162                 "write_len=%d, vec->sge=%p, vec->count=%lu\n",
 163                 rmr, (unsigned long long)to, xdr_off,
 164                 write_len, vec->sge, vec->count);
 165
 166         ctxt = svc_rdma_get_context(xprt);
 167         ctxt->direction = DMA_TO_DEVICE;
 168         sge = ctxt->sge;
 169
 170         /* Find the SGE associated with xdr_off */
 171         for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count;
 172              xdr_sge_no++) {
 173                 if (vec->sge[xdr_sge_no].iov_len > bc)
 174                         break;
 175                 bc -= vec->sge[xdr_sge_no].iov_len;
 176         }
 177
 178         sge_off = bc;
 179         bc = write_len;
 180         sge_no = 0;
 181
 182         /* Copy the remaining SGE */
 183         while (bc != 0) {
 184                 sge_bytes = min_t(size_t,
 185                           bc, vec->sge[xdr_sge_no].iov_len-sge_off);
 186                 sge[sge_no].length = sge_bytes;
 187                 sge[sge_no].addr =
 188                         dma_map_xdr(xprt, &rqstp->rq_res, xdr_off,
 189                                     sge_bytes, DMA_TO_DEVICE);
 190                 xdr_off += sge_bytes;
 191                 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
 192                                          sge[sge_no].addr))
 193                         goto err;
 194                 atomic_inc(&xprt->sc_dma_used);
 195                 sge[sge_no].lkey = xprt->sc_dma_lkey;
 196                 ctxt->count++;
 197                 sge_off = 0;
 198                 sge_no++;
 199                 xdr_sge_no++;
 200                 if (xdr_sge_no > vec->count) {
 201                         pr_err("svcrdma: Too many sges (%d)\n", xdr_sge_no);
 202                         goto err;
 203                 }
 204                 bc -= sge_bytes;
 205                 if (sge_no == xprt->sc_max_sge)
 206                         break;
 207         }
 208
 209         /* Prepare WRITE WR */
 210         memset(&write_wr, 0, sizeof write_wr);
 211         ctxt->wr_op = IB_WR_RDMA_WRITE;
 212         write_wr.wr_id = (unsigned long)ctxt;
 213         write_wr.sg_list = &sge[0];
 214         write_wr.num_sge = sge_no;
 215         write_wr.opcode = IB_WR_RDMA_WRITE;
 216         write_wr.send_flags = IB_SEND_SIGNALED;
 217         write_wr.wr.rdma.rkey = rmr;
 218         write_wr.wr.rdma.remote_addr = to;
 219
 220         /* Post It */
 221         atomic_inc(&rdma_stat_write);
 222         if (svc_rdma_send(xprt, &write_wr))
 223                 goto err;
 224         return write_len - bc;
 225  err:
 226         svc_rdma_unmap_dma(ctxt);
 227         svc_rdma_put_context(ctxt, 0);
 228         /* Fatal error, close transport */
 229         return -EIO;
 230 }
 231
 232 static int send_write_chunks(struct svcxprt_rdma *xprt,
 233                              struct rpcrdma_msg *rdma_argp,
 234                              struct rpcrdma_msg *rdma_resp,
 235                              struct svc_rqst *rqstp,
 236                              struct svc_rdma_req_map *vec)
 237 {
 238         u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
 239         int write_len;
 240         u32 xdr_off;
 241         int chunk_off;
 242         int chunk_no;
 243         struct rpcrdma_write_array *arg_ary;
 244         struct rpcrdma_write_array *res_ary;
 245         int ret;
 246
 247         arg_ary = svc_rdma_get_write_array(rdma_argp);
 248         if (!arg_ary)
 249                 return 0;
 250         res_ary = (struct rpcrdma_write_array *)
 251                 &rdma_resp->rm_body.rm_chunks[1];
 252
 253         /* Write chunks start at the pagelist */
 254         for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
 255              xfer_len && chunk_no < arg_ary->wc_nchunks;
 256              chunk_no++) {
 257                 struct rpcrdma_segment *arg_ch;
 258                 u64 rs_offset;
 259
 260                 arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
 261                 write_len = min(xfer_len, ntohl(arg_ch->rs_length));
 262
 263                 /* Prepare the response chunk given the length actually
 264                  * written */
 265                 xdr_decode_hyper((__be32 *)&arg_ch->rs_offset, &rs_offset);
 266                 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
 267                                                 arg_ch->rs_handle,
 268                                                 arg_ch->rs_offset,
 269                                                 write_len);
 270                 chunk_off = 0;
 271                 while (write_len) {
 272                         ret = send_write(xprt, rqstp,
 273                                          ntohl(arg_ch->rs_handle),
 274                                          rs_offset + chunk_off,
 275                                          xdr_off,
 276                                          write_len,
 277                                          vec);
 278                         if (ret <= 0) {
 279                                 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
 280                                         ret);
 281                                 return -EIO;
 282                         }
 283                         chunk_off += ret;
 284                         xdr_off += ret;
 285                         xfer_len -= ret;
 286                         write_len -= ret;
 287                 }
 288         }
 289         /* Update the req with the number of chunks actually used */
 290         svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no);
 291
 292         return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
 293 }
 294
 295 static int send_reply_chunks(struct svcxprt_rdma *xprt,
 296                              struct rpcrdma_msg *rdma_argp,
 297                              struct rpcrdma_msg *rdma_resp,
 298                              struct svc_rqst *rqstp,
 299                              struct svc_rdma_req_map *vec)
 300 {
 301         u32 xfer_len = rqstp->rq_res.len;
 302         int write_len;
 303         u32 xdr_off;
 304         int chunk_no;
 305         int chunk_off;
 306         int nchunks;
 307         struct rpcrdma_segment *ch;
 308         struct rpcrdma_write_array *arg_ary;
 309         struct rpcrdma_write_array *res_ary;
 310         int ret;
 311
 312         arg_ary = svc_rdma_get_reply_array(rdma_argp);
 313         if (!arg_ary)
 314                 return 0;
 315         /* XXX: need to fix when reply lists occur with read-list and or
 316          * write-list */
 317         res_ary = (struct rpcrdma_write_array *)
 318                 &rdma_resp->rm_body.rm_chunks[2];
 319
 320         /* xdr offset starts at RPC message */
 321         nchunks = ntohl(arg_ary->wc_nchunks);
 322         for (xdr_off = 0, chunk_no = 0;
 323              xfer_len && chunk_no < nchunks;
 324              chunk_no++) {
 325                 u64 rs_offset;
 326                 ch = &arg_ary->wc_array[chunk_no].wc_target;
 327                 write_len = min(xfer_len, htonl(ch->rs_length));
 328
 329                 /* Prepare the reply chunk given the length actually
 330                  * written */
 331                 xdr_decode_hyper((__be32 *)&ch->rs_offset, &rs_offset);
 332                 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
 333                                                 ch->rs_handle, ch->rs_offset,
 334                                                 write_len);
 335                 chunk_off = 0;
 336                 while (write_len) {
 337                         ret = send_write(xprt, rqstp,
 338                                          ntohl(ch->rs_handle),
 339                                          rs_offset + chunk_off,
 340                                          xdr_off,
 341                                          write_len,
 342                                          vec);
 343                         if (ret <= 0) {
 344                                 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
 345                                         ret);
 346                                 return -EIO;
 347                         }
 348                         chunk_off += ret;
 349                         xdr_off += ret;
 350                         xfer_len -= ret;
 351                         write_len -= ret;
 352                 }
 353         }
 354         /* Update the req with the number of chunks actually used */
 355         svc_rdma_xdr_encode_reply_array(res_ary, chunk_no);
 356
 357         return rqstp->rq_res.len;
 358 }
 359
 360 /* This function prepares the portion of the RPCRDMA message to be
 361  * sent in the RDMA_SEND. This function is called after data sent via
 362  * RDMA has already been transmitted. There are three cases:
 363  * - The RPCRDMA header, RPC header, and payload are all sent in a
 364  *   single RDMA_SEND. This is the "inline" case.
 365  * - The RPCRDMA header and some portion of the RPC header and data
 366  *   are sent via this RDMA_SEND and another portion of the data is
 367  *   sent via RDMA.
 368  * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC
 369  *   header and data are all transmitted via RDMA.
 370  * In all three cases, this function prepares the RPCRDMA header in
 371  * sge[0], the 'type' parameter indicates the type to place in the
 372  * RPCRDMA header, and the 'byte_count' field indicates how much of
 373  * the XDR to include in this RDMA_SEND. NB: The offset of the payload
 374  * to send is zero in the XDR.
 375  */
 376 static int send_reply(struct svcxprt_rdma *rdma,
 377                       struct svc_rqst *rqstp,
 378                       struct page *page,
 379                       struct rpcrdma_msg *rdma_resp,
 380                       struct svc_rdma_op_ctxt *ctxt,
 381                       struct svc_rdma_req_map *vec,
 382                       int byte_count)
 383 {
 384         struct ib_send_wr send_wr;
 385         int sge_no;
 386         int sge_bytes;
 387         int page_no;
 388         int pages;
 389         int ret;
 390
 391         /* Post a recv buffer to handle another request. */
 392         ret = svc_rdma_post_recv(rdma);
 393         if (ret) {
 394                 printk(KERN_INFO
 395                        "svcrdma: could not post a receive buffer, err=%d."
 396                        "Closing transport %p.\n", ret, rdma);
 397                 set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
 398                 svc_rdma_put_context(ctxt, 0);
 399                 return -ENOTCONN;
 400         }
 401
 402         /* Prepare the context */
 403         ctxt->pages[0] = page;
 404         ctxt->count = 1;
 405
 406         /* Prepare the SGE for the RPCRDMA Header */
 407         ctxt->sge[0].lkey = rdma->sc_dma_lkey;
 408         ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
 409         ctxt->sge[0].addr =
 410             ib_dma_map_page(rdma->sc_cm_id->device, page, 0,
 411                             ctxt->sge[0].length, DMA_TO_DEVICE);
 412         if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr))
 413                 goto err;
 414         atomic_inc(&rdma->sc_dma_used);
 415
 416         ctxt->direction = DMA_TO_DEVICE;
 417
 418         /* Map the payload indicated by 'byte_count' */
 419         for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
 420                 int xdr_off = 0;
 421                 sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);
 422                 byte_count -= sge_bytes;
 423                 ctxt->sge[sge_no].addr =
 424                         dma_map_xdr(rdma, &rqstp->rq_res, xdr_off,
 425                                     sge_bytes, DMA_TO_DEVICE);
 426                 xdr_off += sge_bytes;
 427                 if (ib_dma_mapping_error(rdma->sc_cm_id->device,
 428                                          ctxt->sge[sge_no].addr))
 429                         goto err;
 430                 atomic_inc(&rdma->sc_dma_used);
 431                 ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
 432                 ctxt->sge[sge_no].length = sge_bytes;
 433         }
 434         if (byte_count != 0) {
 435                 pr_err("svcrdma: Could not map %d bytes\n", byte_count);
 436                 goto err;
 437         }
 438
 439         /* Save all respages in the ctxt and remove them from the
 440          * respages array. They are our pages until the I/O
 441          * completes.
 442          */
 443         pages = rqstp->rq_next_page - rqstp->rq_respages;
 444         for (page_no = 0; page_no < pages; page_no++) {
 445                 ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
 446                 ctxt->count++;
 447                 rqstp->rq_respages[page_no] = NULL;
 448                 /*
 449                  * If there are more pages than SGE, terminate SGE
 450                  * list so that svc_rdma_unmap_dma doesn't attempt to
 451                  * unmap garbage.
 452                  */
 453                 if (page_no+1 >= sge_no)
 454                         ctxt->sge[page_no+1].length = 0;
 455         }
 456         rqstp->rq_next_page = rqstp->rq_respages + 1;
 457
 458         if (sge_no > rdma->sc_max_sge) {
 459                 pr_err("svcrdma: Too many sges (%d)\n", sge_no);
 460                 goto err;
 461         }
 462         memset(&send_wr, 0, sizeof send_wr);
 463         ctxt->wr_op = IB_WR_SEND;
 464         send_wr.wr_id = (unsigned long)ctxt;
 465         send_wr.sg_list = ctxt->sge;
 466         send_wr.num_sge = sge_no;
 467         send_wr.opcode = IB_WR_SEND;
 468         send_wr.send_flags =  IB_SEND_SIGNALED;
 469
 470         ret = svc_rdma_send(rdma, &send_wr);
 471         if (ret)
 472                 goto err;
 473
 474         return 0;
 475
 476  err:
 477         svc_rdma_unmap_dma(ctxt);
 478         svc_rdma_put_context(ctxt, 1);
 479         return -EIO;
 480 }
 481
 482 void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
 483 {
 484 }
 485
 486 int svc_rdma_sendto(struct svc_rqst *rqstp)
 487 {
 488         struct svc_xprt *xprt = rqstp->rq_xprt;
 489         struct svcxprt_rdma *rdma =
 490                 container_of(xprt, struct svcxprt_rdma, sc_xprt);
 491         struct rpcrdma_msg *rdma_argp;
 492         struct rpcrdma_msg *rdma_resp;
 493         struct rpcrdma_write_array *reply_ary;
 494         enum rpcrdma_proc reply_type;
 495         int ret;
 496         int inline_bytes;
 497         struct page *res_page;
 498         struct svc_rdma_op_ctxt *ctxt;
 499         struct svc_rdma_req_map *vec;
 500
 501         dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
 502
 503         /* Get the RDMA request header. The receive logic always
 504          * places this at the start of page 0.
 505          */
 506         rdma_argp = page_address(rqstp->rq_pages[0]);
 507
 508         /* Build an req vec for the XDR */
 509         ctxt = svc_rdma_get_context(rdma);
 510         ctxt->direction = DMA_TO_DEVICE;
 511         vec = svc_rdma_get_req_map();
 512         ret = map_xdr(rdma, &rqstp->rq_res, vec);
 513         if (ret)
 514                 goto err0;
 515         inline_bytes = rqstp->rq_res.len;
 516
 517         /* Create the RDMA response header */
 518         res_page = svc_rdma_get_page();
 519         rdma_resp = page_address(res_page);
 520         reply_ary = svc_rdma_get_reply_array(rdma_argp);
 521         if (reply_ary)
 522                 reply_type = RDMA_NOMSG;
 523         else
 524                 reply_type = RDMA_MSG;
 525         svc_rdma_xdr_encode_reply_header(rdma, rdma_argp,
 526                                          rdma_resp, reply_type);
 527
 528         /* Send any write-chunk data and build resp write-list */
 529         ret = send_write_chunks(rdma, rdma_argp, rdma_resp,
 530                                 rqstp, vec);
 531         if (ret < 0) {
 532                 printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
 533                        ret);
 534                 goto err1;
 535         }
 536         inline_bytes -= ret;
 537
 538         /* Send any reply-list data and update resp reply-list */
 539         ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
 540                                 rqstp, vec);
 541         if (ret < 0) {
 542                 printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
 543                        ret);
 544                 goto err1;
 545         }
 546         inline_bytes -= ret;
 547
 548         ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
 549                          inline_bytes);
 550         svc_rdma_put_req_map(vec);
 551         dprintk("svcrdma: send_reply returns %d\n", ret);
 552         return ret;
 553
 554  err1:
 555         put_page(res_page);
 556  err0:
 557         svc_rdma_put_req_map(vec);
 558         svc_rdma_put_context(ctxt, 0);
 559         return ret;
 560 }