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