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 /* 54 * Replace the pages in the rq_argpages array with the pages from the SGE in 55 * the RDMA_RECV completion. The SGL should contain full pages up until the 56 * last one. 57 */ 58 static void rdma_build_arg_xdr(struct svc_rqst *rqstp, 59 struct svc_rdma_op_ctxt *ctxt, 60 u32 byte_count) 61 { 62 struct rpcrdma_msg *rmsgp; 63 struct page *page; 64 u32 bc; 65 int sge_no; 66 67 /* Swap the page in the SGE with the page in argpages */ 68 page = ctxt->pages[0]; 69 put_page(rqstp->rq_pages[0]); 70 rqstp->rq_pages[0] = page; 71 72 /* Set up the XDR head */ 73 rqstp->rq_arg.head[0].iov_base = page_address(page); 74 rqstp->rq_arg.head[0].iov_len = 75 min_t(size_t, byte_count, ctxt->sge[0].length); 76 rqstp->rq_arg.len = byte_count; 77 rqstp->rq_arg.buflen = byte_count; 78 79 /* Compute bytes past head in the SGL */ 80 bc = byte_count - rqstp->rq_arg.head[0].iov_len; 81 82 /* If data remains, store it in the pagelist */ 83 rqstp->rq_arg.page_len = bc; 84 rqstp->rq_arg.page_base = 0; 85 86 /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */ 87 rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base; 88 if (rmsgp->rm_type == rdma_nomsg) 89 rqstp->rq_arg.pages = &rqstp->rq_pages[0]; 90 else 91 rqstp->rq_arg.pages = &rqstp->rq_pages[1]; 92 93 sge_no = 1; 94 while (bc && sge_no < ctxt->count) { 95 page = ctxt->pages[sge_no]; 96 put_page(rqstp->rq_pages[sge_no]); 97 rqstp->rq_pages[sge_no] = page; 98 bc -= min_t(u32, bc, ctxt->sge[sge_no].length); 99 rqstp->rq_arg.buflen += ctxt->sge[sge_no].length; 100 sge_no++; 101 } 102 rqstp->rq_respages = &rqstp->rq_pages[sge_no]; 103 rqstp->rq_next_page = rqstp->rq_respages + 1; 104 105 /* If not all pages were used from the SGL, free the remaining ones */ 106 bc = sge_no; 107 while (sge_no < ctxt->count) { 108 page = ctxt->pages[sge_no++]; 109 put_page(page); 110 } 111 ctxt->count = bc; 112 113 /* Set up tail */ 114 rqstp->rq_arg.tail[0].iov_base = NULL; 115 rqstp->rq_arg.tail[0].iov_len = 0; 116 } 117 118 /* Issue an RDMA_READ using the local lkey to map the data sink */ 119 int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt, 120 struct svc_rqst *rqstp, 121 struct svc_rdma_op_ctxt *head, 122 int *page_no, 123 u32 *page_offset, 124 u32 rs_handle, 125 u32 rs_length, 126 u64 rs_offset, 127 bool last) 128 { 129 struct ib_send_wr read_wr; 130 int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT; 131 struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt); 132 int ret, read, pno; 133 u32 pg_off = *page_offset; 134 u32 pg_no = *page_no; 135 136 ctxt->direction = DMA_FROM_DEVICE; 137 ctxt->read_hdr = head; 138 pages_needed = min_t(int, pages_needed, xprt->sc_max_sge_rd); 139 read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset, 140 rs_length); 141 142 for (pno = 0; pno < pages_needed; pno++) { 143 int len = min_t(int, rs_length, PAGE_SIZE - pg_off); 144 145 head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no]; 146 head->arg.page_len += len; 147 head->arg.len += len; 148 if (!pg_off) 149 head->count++; 150 rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1]; 151 rqstp->rq_next_page = rqstp->rq_respages + 1; 152 ctxt->sge[pno].addr = 153 ib_dma_map_page(xprt->sc_cm_id->device, 154 head->arg.pages[pg_no], pg_off, 155 PAGE_SIZE - pg_off, 156 DMA_FROM_DEVICE); 157 ret = ib_dma_mapping_error(xprt->sc_cm_id->device, 158 ctxt->sge[pno].addr); 159 if (ret) 160 goto err; 161 atomic_inc(&xprt->sc_dma_used); 162 163 /* The lkey here is either a local dma lkey or a dma_mr lkey */ 164 ctxt->sge[pno].lkey = xprt->sc_dma_lkey; 165 ctxt->sge[pno].length = len; 166 ctxt->count++; 167 168 /* adjust offset and wrap to next page if needed */ 169 pg_off += len; 170 if (pg_off == PAGE_SIZE) { 171 pg_off = 0; 172 pg_no++; 173 } 174 rs_length -= len; 175 } 176 177 if (last && rs_length == 0) 178 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 179 else 180 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 181 182 memset(&read_wr, 0, sizeof(read_wr)); 183 read_wr.wr_id = (unsigned long)ctxt; 184 read_wr.opcode = IB_WR_RDMA_READ; 185 ctxt->wr_op = read_wr.opcode; 186 read_wr.send_flags = IB_SEND_SIGNALED; 187 read_wr.wr.rdma.rkey = rs_handle; 188 read_wr.wr.rdma.remote_addr = rs_offset; 189 read_wr.sg_list = ctxt->sge; 190 read_wr.num_sge = pages_needed; 191 192 ret = svc_rdma_send(xprt, &read_wr); 193 if (ret) { 194 pr_err("svcrdma: Error %d posting RDMA_READ\n", ret); 195 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 196 goto err; 197 } 198 199 /* return current location in page array */ 200 *page_no = pg_no; 201 *page_offset = pg_off; 202 ret = read; 203 atomic_inc(&rdma_stat_read); 204 return ret; 205 err: 206 svc_rdma_unmap_dma(ctxt); 207 svc_rdma_put_context(ctxt, 0); 208 return ret; 209 } 210 211 /* Issue an RDMA_READ using an FRMR to map the data sink */ 212 int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt, 213 struct svc_rqst *rqstp, 214 struct svc_rdma_op_ctxt *head, 215 int *page_no, 216 u32 *page_offset, 217 u32 rs_handle, 218 u32 rs_length, 219 u64 rs_offset, 220 bool last) 221 { 222 struct ib_send_wr read_wr; 223 struct ib_send_wr inv_wr; 224 struct ib_send_wr fastreg_wr; 225 u8 key; 226 int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT; 227 struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt); 228 struct svc_rdma_fastreg_mr *frmr = svc_rdma_get_frmr(xprt); 229 int ret, read, pno; 230 u32 pg_off = *page_offset; 231 u32 pg_no = *page_no; 232 233 if (IS_ERR(frmr)) 234 return -ENOMEM; 235 236 ctxt->direction = DMA_FROM_DEVICE; 237 ctxt->frmr = frmr; 238 pages_needed = min_t(int, pages_needed, xprt->sc_frmr_pg_list_len); 239 read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset, 240 rs_length); 241 242 frmr->kva = page_address(rqstp->rq_arg.pages[pg_no]); 243 frmr->direction = DMA_FROM_DEVICE; 244 frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE); 245 frmr->map_len = pages_needed << PAGE_SHIFT; 246 frmr->page_list_len = pages_needed; 247 248 for (pno = 0; pno < pages_needed; pno++) { 249 int len = min_t(int, rs_length, PAGE_SIZE - pg_off); 250 251 head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no]; 252 head->arg.page_len += len; 253 head->arg.len += len; 254 if (!pg_off) 255 head->count++; 256 rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1]; 257 rqstp->rq_next_page = rqstp->rq_respages + 1; 258 frmr->page_list->page_list[pno] = 259 ib_dma_map_page(xprt->sc_cm_id->device, 260 head->arg.pages[pg_no], 0, 261 PAGE_SIZE, DMA_FROM_DEVICE); 262 ret = ib_dma_mapping_error(xprt->sc_cm_id->device, 263 frmr->page_list->page_list[pno]); 264 if (ret) 265 goto err; 266 atomic_inc(&xprt->sc_dma_used); 267 268 /* adjust offset and wrap to next page if needed */ 269 pg_off += len; 270 if (pg_off == PAGE_SIZE) { 271 pg_off = 0; 272 pg_no++; 273 } 274 rs_length -= len; 275 } 276 277 if (last && rs_length == 0) 278 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 279 else 280 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 281 282 /* Bump the key */ 283 key = (u8)(frmr->mr->lkey & 0x000000FF); 284 ib_update_fast_reg_key(frmr->mr, ++key); 285 286 ctxt->sge[0].addr = (unsigned long)frmr->kva + *page_offset; 287 ctxt->sge[0].lkey = frmr->mr->lkey; 288 ctxt->sge[0].length = read; 289 ctxt->count = 1; 290 ctxt->read_hdr = head; 291 292 /* Prepare FASTREG WR */ 293 memset(&fastreg_wr, 0, sizeof(fastreg_wr)); 294 fastreg_wr.opcode = IB_WR_FAST_REG_MR; 295 fastreg_wr.send_flags = IB_SEND_SIGNALED; 296 fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva; 297 fastreg_wr.wr.fast_reg.page_list = frmr->page_list; 298 fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len; 299 fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT; 300 fastreg_wr.wr.fast_reg.length = frmr->map_len; 301 fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags; 302 fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey; 303 fastreg_wr.next = &read_wr; 304 305 /* Prepare RDMA_READ */ 306 memset(&read_wr, 0, sizeof(read_wr)); 307 read_wr.send_flags = IB_SEND_SIGNALED; 308 read_wr.wr.rdma.rkey = rs_handle; 309 read_wr.wr.rdma.remote_addr = rs_offset; 310 read_wr.sg_list = ctxt->sge; 311 read_wr.num_sge = 1; 312 if (xprt->sc_dev_caps & SVCRDMA_DEVCAP_READ_W_INV) { 313 read_wr.opcode = IB_WR_RDMA_READ_WITH_INV; 314 read_wr.wr_id = (unsigned long)ctxt; 315 read_wr.ex.invalidate_rkey = ctxt->frmr->mr->lkey; 316 } else { 317 read_wr.opcode = IB_WR_RDMA_READ; 318 read_wr.next = &inv_wr; 319 /* Prepare invalidate */ 320 memset(&inv_wr, 0, sizeof(inv_wr)); 321 inv_wr.wr_id = (unsigned long)ctxt; 322 inv_wr.opcode = IB_WR_LOCAL_INV; 323 inv_wr.send_flags = IB_SEND_SIGNALED | IB_SEND_FENCE; 324 inv_wr.ex.invalidate_rkey = frmr->mr->lkey; 325 } 326 ctxt->wr_op = read_wr.opcode; 327 328 /* Post the chain */ 329 ret = svc_rdma_send(xprt, &fastreg_wr); 330 if (ret) { 331 pr_err("svcrdma: Error %d posting RDMA_READ\n", ret); 332 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 333 goto err; 334 } 335 336 /* return current location in page array */ 337 *page_no = pg_no; 338 *page_offset = pg_off; 339 ret = read; 340 atomic_inc(&rdma_stat_read); 341 return ret; 342 err: 343 svc_rdma_unmap_dma(ctxt); 344 svc_rdma_put_context(ctxt, 0); 345 svc_rdma_put_frmr(xprt, frmr); 346 return ret; 347 } 348 349 static unsigned int 350 rdma_rcl_chunk_count(struct rpcrdma_read_chunk *ch) 351 { 352 unsigned int count; 353 354 for (count = 0; ch->rc_discrim != xdr_zero; ch++) 355 count++; 356 return count; 357 } 358 359 /* If there was additional inline content, append it to the end of arg.pages. 360 * Tail copy has to be done after the reader function has determined how many 361 * pages are needed for RDMA READ. 362 */ 363 static int 364 rdma_copy_tail(struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head, 365 u32 position, u32 byte_count, u32 page_offset, int page_no) 366 { 367 char *srcp, *destp; 368 int ret; 369 370 ret = 0; 371 srcp = head->arg.head[0].iov_base + position; 372 byte_count = head->arg.head[0].iov_len - position; 373 if (byte_count > PAGE_SIZE) { 374 dprintk("svcrdma: large tail unsupported\n"); 375 return 0; 376 } 377 378 /* Fit as much of the tail on the current page as possible */ 379 if (page_offset != PAGE_SIZE) { 380 destp = page_address(rqstp->rq_arg.pages[page_no]); 381 destp += page_offset; 382 while (byte_count--) { 383 *destp++ = *srcp++; 384 page_offset++; 385 if (page_offset == PAGE_SIZE && byte_count) 386 goto more; 387 } 388 goto done; 389 } 390 391 more: 392 /* Fit the rest on the next page */ 393 page_no++; 394 destp = page_address(rqstp->rq_arg.pages[page_no]); 395 while (byte_count--) 396 *destp++ = *srcp++; 397 398 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1]; 399 rqstp->rq_next_page = rqstp->rq_respages + 1; 400 401 done: 402 byte_count = head->arg.head[0].iov_len - position; 403 head->arg.page_len += byte_count; 404 head->arg.len += byte_count; 405 head->arg.buflen += byte_count; 406 return 1; 407 } 408 409 static int rdma_read_chunks(struct svcxprt_rdma *xprt, 410 struct rpcrdma_msg *rmsgp, 411 struct svc_rqst *rqstp, 412 struct svc_rdma_op_ctxt *head) 413 { 414 int page_no, ret; 415 struct rpcrdma_read_chunk *ch; 416 u32 handle, page_offset, byte_count; 417 u32 position; 418 u64 rs_offset; 419 bool last; 420 421 /* If no read list is present, return 0 */ 422 ch = svc_rdma_get_read_chunk(rmsgp); 423 if (!ch) 424 return 0; 425 426 if (rdma_rcl_chunk_count(ch) > RPCSVC_MAXPAGES) 427 return -EINVAL; 428 429 /* The request is completed when the RDMA_READs complete. The 430 * head context keeps all the pages that comprise the 431 * request. 432 */ 433 head->arg.head[0] = rqstp->rq_arg.head[0]; 434 head->arg.tail[0] = rqstp->rq_arg.tail[0]; 435 head->hdr_count = head->count; 436 head->arg.page_base = 0; 437 head->arg.page_len = 0; 438 head->arg.len = rqstp->rq_arg.len; 439 head->arg.buflen = rqstp->rq_arg.buflen; 440 441 ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; 442 position = be32_to_cpu(ch->rc_position); 443 444 /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */ 445 if (position == 0) { 446 head->arg.pages = &head->pages[0]; 447 page_offset = head->byte_len; 448 } else { 449 head->arg.pages = &head->pages[head->count]; 450 page_offset = 0; 451 } 452 453 ret = 0; 454 page_no = 0; 455 for (; ch->rc_discrim != xdr_zero; ch++) { 456 if (be32_to_cpu(ch->rc_position) != position) 457 goto err; 458 459 handle = be32_to_cpu(ch->rc_target.rs_handle), 460 byte_count = be32_to_cpu(ch->rc_target.rs_length); 461 xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset, 462 &rs_offset); 463 464 while (byte_count > 0) { 465 last = (ch + 1)->rc_discrim == xdr_zero; 466 ret = xprt->sc_reader(xprt, rqstp, head, 467 &page_no, &page_offset, 468 handle, byte_count, 469 rs_offset, last); 470 if (ret < 0) 471 goto err; 472 byte_count -= ret; 473 rs_offset += ret; 474 head->arg.buflen += ret; 475 } 476 } 477 478 /* Read list may need XDR round-up (see RFC 5666, s. 3.7) */ 479 if (page_offset & 3) { 480 u32 pad = 4 - (page_offset & 3); 481 482 head->arg.page_len += pad; 483 head->arg.len += pad; 484 head->arg.buflen += pad; 485 page_offset += pad; 486 } 487 488 ret = 1; 489 if (position && position < head->arg.head[0].iov_len) 490 ret = rdma_copy_tail(rqstp, head, position, 491 byte_count, page_offset, page_no); 492 head->arg.head[0].iov_len = position; 493 head->position = position; 494 495 err: 496 /* Detach arg pages. svc_recv will replenish them */ 497 for (page_no = 0; 498 &rqstp->rq_pages[page_no] < rqstp->rq_respages; page_no++) 499 rqstp->rq_pages[page_no] = NULL; 500 501 return ret; 502 } 503 504 static int rdma_read_complete(struct svc_rqst *rqstp, 505 struct svc_rdma_op_ctxt *head) 506 { 507 int page_no; 508 int ret; 509 510 /* Copy RPC pages */ 511 for (page_no = 0; page_no < head->count; page_no++) { 512 put_page(rqstp->rq_pages[page_no]); 513 rqstp->rq_pages[page_no] = head->pages[page_no]; 514 } 515 516 /* Adjustments made for RDMA_NOMSG type requests */ 517 if (head->position == 0) { 518 if (head->arg.len <= head->sge[0].length) { 519 head->arg.head[0].iov_len = head->arg.len - 520 head->byte_len; 521 head->arg.page_len = 0; 522 } else { 523 head->arg.head[0].iov_len = head->sge[0].length - 524 head->byte_len; 525 head->arg.page_len = head->arg.len - 526 head->sge[0].length; 527 } 528 } 529 530 /* Point rq_arg.pages past header */ 531 rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count]; 532 rqstp->rq_arg.page_len = head->arg.page_len; 533 rqstp->rq_arg.page_base = head->arg.page_base; 534 535 /* rq_respages starts after the last arg page */ 536 rqstp->rq_respages = &rqstp->rq_pages[page_no]; 537 rqstp->rq_next_page = rqstp->rq_respages + 1; 538 539 /* Rebuild rq_arg head and tail. */ 540 rqstp->rq_arg.head[0] = head->arg.head[0]; 541 rqstp->rq_arg.tail[0] = head->arg.tail[0]; 542 rqstp->rq_arg.len = head->arg.len; 543 rqstp->rq_arg.buflen = head->arg.buflen; 544 545 /* Free the context */ 546 svc_rdma_put_context(head, 0); 547 548 /* XXX: What should this be? */ 549 rqstp->rq_prot = IPPROTO_MAX; 550 svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt); 551 552 ret = rqstp->rq_arg.head[0].iov_len 553 + rqstp->rq_arg.page_len 554 + rqstp->rq_arg.tail[0].iov_len; 555 dprintk("svcrdma: deferred read ret=%d, rq_arg.len=%u, " 556 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zu\n", 557 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, 558 rqstp->rq_arg.head[0].iov_len); 559 560 return ret; 561 } 562 563 /* 564 * Set up the rqstp thread context to point to the RQ buffer. If 565 * necessary, pull additional data from the client with an RDMA_READ 566 * request. 567 */ 568 int svc_rdma_recvfrom(struct svc_rqst *rqstp) 569 { 570 struct svc_xprt *xprt = rqstp->rq_xprt; 571 struct svcxprt_rdma *rdma_xprt = 572 container_of(xprt, struct svcxprt_rdma, sc_xprt); 573 struct svc_rdma_op_ctxt *ctxt = NULL; 574 struct rpcrdma_msg *rmsgp; 575 int ret = 0; 576 int len; 577 578 dprintk("svcrdma: rqstp=%p\n", rqstp); 579 580 spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); 581 if (!list_empty(&rdma_xprt->sc_read_complete_q)) { 582 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, 583 struct svc_rdma_op_ctxt, 584 dto_q); 585 list_del_init(&ctxt->dto_q); 586 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); 587 return rdma_read_complete(rqstp, ctxt); 588 } else if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { 589 ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, 590 struct svc_rdma_op_ctxt, 591 dto_q); 592 list_del_init(&ctxt->dto_q); 593 } else { 594 atomic_inc(&rdma_stat_rq_starve); 595 clear_bit(XPT_DATA, &xprt->xpt_flags); 596 ctxt = NULL; 597 } 598 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); 599 if (!ctxt) { 600 /* This is the EAGAIN path. The svc_recv routine will 601 * return -EAGAIN, the nfsd thread will go to call into 602 * svc_recv again and we shouldn't be on the active 603 * transport list 604 */ 605 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) 606 goto close_out; 607 608 goto out; 609 } 610 dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n", 611 ctxt, rdma_xprt, rqstp, ctxt->wc_status); 612 atomic_inc(&rdma_stat_recv); 613 614 /* Build up the XDR from the receive buffers. */ 615 rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len); 616 617 /* Decode the RDMA header. */ 618 len = svc_rdma_xdr_decode_req(&rmsgp, rqstp); 619 rqstp->rq_xprt_hlen = len; 620 621 /* If the request is invalid, reply with an error */ 622 if (len < 0) { 623 if (len == -ENOSYS) 624 svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS); 625 goto close_out; 626 } 627 628 /* Read read-list data. */ 629 ret = rdma_read_chunks(rdma_xprt, rmsgp, rqstp, ctxt); 630 if (ret > 0) { 631 /* read-list posted, defer until data received from client. */ 632 goto defer; 633 } else if (ret < 0) { 634 /* Post of read-list failed, free context. */ 635 svc_rdma_put_context(ctxt, 1); 636 return 0; 637 } 638 639 ret = rqstp->rq_arg.head[0].iov_len 640 + rqstp->rq_arg.page_len 641 + rqstp->rq_arg.tail[0].iov_len; 642 svc_rdma_put_context(ctxt, 0); 643 out: 644 dprintk("svcrdma: ret=%d, rq_arg.len=%u, " 645 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zd\n", 646 ret, rqstp->rq_arg.len, 647 rqstp->rq_arg.head[0].iov_base, 648 rqstp->rq_arg.head[0].iov_len); 649 rqstp->rq_prot = IPPROTO_MAX; 650 svc_xprt_copy_addrs(rqstp, xprt); 651 return ret; 652 653 close_out: 654 if (ctxt) 655 svc_rdma_put_context(ctxt, 1); 656 dprintk("svcrdma: transport %p is closing\n", xprt); 657 /* 658 * Set the close bit and enqueue it. svc_recv will see the 659 * close bit and call svc_xprt_delete 660 */ 661 set_bit(XPT_CLOSE, &xprt->xpt_flags); 662 defer: 663 return 0; 664 } 665