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 (be32_to_cpu(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 static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) 119 { 120 if (rdma_node_get_transport(xprt->sc_cm_id->device->node_type) == 121 RDMA_TRANSPORT_IWARP) 122 return 1; 123 else 124 return min_t(int, sge_count, xprt->sc_max_sge); 125 } 126 127 /* Issue an RDMA_READ using the local lkey to map the data sink */ 128 int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt, 129 struct svc_rqst *rqstp, 130 struct svc_rdma_op_ctxt *head, 131 int *page_no, 132 u32 *page_offset, 133 u32 rs_handle, 134 u32 rs_length, 135 u64 rs_offset, 136 bool last) 137 { 138 struct ib_send_wr read_wr; 139 int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT; 140 struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt); 141 int ret, read, pno; 142 u32 pg_off = *page_offset; 143 u32 pg_no = *page_no; 144 145 ctxt->direction = DMA_FROM_DEVICE; 146 ctxt->read_hdr = head; 147 pages_needed = 148 min_t(int, pages_needed, rdma_read_max_sge(xprt, pages_needed)); 149 read = min_t(int, pages_needed << PAGE_SHIFT, rs_length); 150 151 for (pno = 0; pno < pages_needed; pno++) { 152 int len = min_t(int, rs_length, PAGE_SIZE - pg_off); 153 154 head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no]; 155 head->arg.page_len += len; 156 head->arg.len += len; 157 if (!pg_off) 158 head->count++; 159 rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1]; 160 rqstp->rq_next_page = rqstp->rq_respages + 1; 161 ctxt->sge[pno].addr = 162 ib_dma_map_page(xprt->sc_cm_id->device, 163 head->arg.pages[pg_no], pg_off, 164 PAGE_SIZE - pg_off, 165 DMA_FROM_DEVICE); 166 ret = ib_dma_mapping_error(xprt->sc_cm_id->device, 167 ctxt->sge[pno].addr); 168 if (ret) 169 goto err; 170 atomic_inc(&xprt->sc_dma_used); 171 172 /* The lkey here is either a local dma lkey or a dma_mr lkey */ 173 ctxt->sge[pno].lkey = xprt->sc_dma_lkey; 174 ctxt->sge[pno].length = len; 175 ctxt->count++; 176 177 /* adjust offset and wrap to next page if needed */ 178 pg_off += len; 179 if (pg_off == PAGE_SIZE) { 180 pg_off = 0; 181 pg_no++; 182 } 183 rs_length -= len; 184 } 185 186 if (last && rs_length == 0) 187 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 188 else 189 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 190 191 memset(&read_wr, 0, sizeof(read_wr)); 192 read_wr.wr_id = (unsigned long)ctxt; 193 read_wr.opcode = IB_WR_RDMA_READ; 194 ctxt->wr_op = read_wr.opcode; 195 read_wr.send_flags = IB_SEND_SIGNALED; 196 read_wr.wr.rdma.rkey = rs_handle; 197 read_wr.wr.rdma.remote_addr = rs_offset; 198 read_wr.sg_list = ctxt->sge; 199 read_wr.num_sge = pages_needed; 200 201 ret = svc_rdma_send(xprt, &read_wr); 202 if (ret) { 203 pr_err("svcrdma: Error %d posting RDMA_READ\n", ret); 204 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 205 goto err; 206 } 207 208 /* return current location in page array */ 209 *page_no = pg_no; 210 *page_offset = pg_off; 211 ret = read; 212 atomic_inc(&rdma_stat_read); 213 return ret; 214 err: 215 svc_rdma_unmap_dma(ctxt); 216 svc_rdma_put_context(ctxt, 0); 217 return ret; 218 } 219 220 /* Issue an RDMA_READ using an FRMR to map the data sink */ 221 int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt, 222 struct svc_rqst *rqstp, 223 struct svc_rdma_op_ctxt *head, 224 int *page_no, 225 u32 *page_offset, 226 u32 rs_handle, 227 u32 rs_length, 228 u64 rs_offset, 229 bool last) 230 { 231 struct ib_send_wr read_wr; 232 struct ib_send_wr inv_wr; 233 struct ib_send_wr fastreg_wr; 234 u8 key; 235 int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT; 236 struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt); 237 struct svc_rdma_fastreg_mr *frmr = svc_rdma_get_frmr(xprt); 238 int ret, read, pno; 239 u32 pg_off = *page_offset; 240 u32 pg_no = *page_no; 241 242 if (IS_ERR(frmr)) 243 return -ENOMEM; 244 245 ctxt->direction = DMA_FROM_DEVICE; 246 ctxt->frmr = frmr; 247 pages_needed = min_t(int, pages_needed, xprt->sc_frmr_pg_list_len); 248 read = min_t(int, pages_needed << PAGE_SHIFT, rs_length); 249 250 frmr->kva = page_address(rqstp->rq_arg.pages[pg_no]); 251 frmr->direction = DMA_FROM_DEVICE; 252 frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE); 253 frmr->map_len = pages_needed << PAGE_SHIFT; 254 frmr->page_list_len = pages_needed; 255 256 for (pno = 0; pno < pages_needed; pno++) { 257 int len = min_t(int, rs_length, PAGE_SIZE - pg_off); 258 259 head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no]; 260 head->arg.page_len += len; 261 head->arg.len += len; 262 if (!pg_off) 263 head->count++; 264 rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1]; 265 rqstp->rq_next_page = rqstp->rq_respages + 1; 266 frmr->page_list->page_list[pno] = 267 ib_dma_map_page(xprt->sc_cm_id->device, 268 head->arg.pages[pg_no], 0, 269 PAGE_SIZE, DMA_FROM_DEVICE); 270 ret = ib_dma_mapping_error(xprt->sc_cm_id->device, 271 frmr->page_list->page_list[pno]); 272 if (ret) 273 goto err; 274 atomic_inc(&xprt->sc_dma_used); 275 276 /* adjust offset and wrap to next page if needed */ 277 pg_off += len; 278 if (pg_off == PAGE_SIZE) { 279 pg_off = 0; 280 pg_no++; 281 } 282 rs_length -= len; 283 } 284 285 if (last && rs_length == 0) 286 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 287 else 288 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 289 290 /* Bump the key */ 291 key = (u8)(frmr->mr->lkey & 0x000000FF); 292 ib_update_fast_reg_key(frmr->mr, ++key); 293 294 ctxt->sge[0].addr = (unsigned long)frmr->kva + *page_offset; 295 ctxt->sge[0].lkey = frmr->mr->lkey; 296 ctxt->sge[0].length = read; 297 ctxt->count = 1; 298 ctxt->read_hdr = head; 299 300 /* Prepare FASTREG WR */ 301 memset(&fastreg_wr, 0, sizeof(fastreg_wr)); 302 fastreg_wr.opcode = IB_WR_FAST_REG_MR; 303 fastreg_wr.send_flags = IB_SEND_SIGNALED; 304 fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva; 305 fastreg_wr.wr.fast_reg.page_list = frmr->page_list; 306 fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len; 307 fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT; 308 fastreg_wr.wr.fast_reg.length = frmr->map_len; 309 fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags; 310 fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey; 311 fastreg_wr.next = &read_wr; 312 313 /* Prepare RDMA_READ */ 314 memset(&read_wr, 0, sizeof(read_wr)); 315 read_wr.send_flags = IB_SEND_SIGNALED; 316 read_wr.wr.rdma.rkey = rs_handle; 317 read_wr.wr.rdma.remote_addr = rs_offset; 318 read_wr.sg_list = ctxt->sge; 319 read_wr.num_sge = 1; 320 if (xprt->sc_dev_caps & SVCRDMA_DEVCAP_READ_W_INV) { 321 read_wr.opcode = IB_WR_RDMA_READ_WITH_INV; 322 read_wr.wr_id = (unsigned long)ctxt; 323 read_wr.ex.invalidate_rkey = ctxt->frmr->mr->lkey; 324 } else { 325 read_wr.opcode = IB_WR_RDMA_READ; 326 read_wr.next = &inv_wr; 327 /* Prepare invalidate */ 328 memset(&inv_wr, 0, sizeof(inv_wr)); 329 inv_wr.wr_id = (unsigned long)ctxt; 330 inv_wr.opcode = IB_WR_LOCAL_INV; 331 inv_wr.send_flags = IB_SEND_SIGNALED | IB_SEND_FENCE; 332 inv_wr.ex.invalidate_rkey = frmr->mr->lkey; 333 } 334 ctxt->wr_op = read_wr.opcode; 335 336 /* Post the chain */ 337 ret = svc_rdma_send(xprt, &fastreg_wr); 338 if (ret) { 339 pr_err("svcrdma: Error %d posting RDMA_READ\n", ret); 340 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 341 goto err; 342 } 343 344 /* return current location in page array */ 345 *page_no = pg_no; 346 *page_offset = pg_off; 347 ret = read; 348 atomic_inc(&rdma_stat_read); 349 return ret; 350 err: 351 svc_rdma_unmap_dma(ctxt); 352 svc_rdma_put_context(ctxt, 0); 353 svc_rdma_put_frmr(xprt, frmr); 354 return ret; 355 } 356 357 static unsigned int 358 rdma_rcl_chunk_count(struct rpcrdma_read_chunk *ch) 359 { 360 unsigned int count; 361 362 for (count = 0; ch->rc_discrim != xdr_zero; ch++) 363 count++; 364 return count; 365 } 366 367 /* If there was additional inline content, append it to the end of arg.pages. 368 * Tail copy has to be done after the reader function has determined how many 369 * pages are needed for RDMA READ. 370 */ 371 static int 372 rdma_copy_tail(struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head, 373 u32 position, u32 byte_count, u32 page_offset, int page_no) 374 { 375 char *srcp, *destp; 376 int ret; 377 378 ret = 0; 379 srcp = head->arg.head[0].iov_base + position; 380 byte_count = head->arg.head[0].iov_len - position; 381 if (byte_count > PAGE_SIZE) { 382 dprintk("svcrdma: large tail unsupported\n"); 383 return 0; 384 } 385 386 /* Fit as much of the tail on the current page as possible */ 387 if (page_offset != PAGE_SIZE) { 388 destp = page_address(rqstp->rq_arg.pages[page_no]); 389 destp += page_offset; 390 while (byte_count--) { 391 *destp++ = *srcp++; 392 page_offset++; 393 if (page_offset == PAGE_SIZE && byte_count) 394 goto more; 395 } 396 goto done; 397 } 398 399 more: 400 /* Fit the rest on the next page */ 401 page_no++; 402 destp = page_address(rqstp->rq_arg.pages[page_no]); 403 while (byte_count--) 404 *destp++ = *srcp++; 405 406 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1]; 407 rqstp->rq_next_page = rqstp->rq_respages + 1; 408 409 done: 410 byte_count = head->arg.head[0].iov_len - position; 411 head->arg.page_len += byte_count; 412 head->arg.len += byte_count; 413 head->arg.buflen += byte_count; 414 return 1; 415 } 416 417 static int rdma_read_chunks(struct svcxprt_rdma *xprt, 418 struct rpcrdma_msg *rmsgp, 419 struct svc_rqst *rqstp, 420 struct svc_rdma_op_ctxt *head) 421 { 422 int page_no, ret; 423 struct rpcrdma_read_chunk *ch; 424 u32 handle, page_offset, byte_count; 425 u32 position; 426 u64 rs_offset; 427 bool last; 428 429 /* If no read list is present, return 0 */ 430 ch = svc_rdma_get_read_chunk(rmsgp); 431 if (!ch) 432 return 0; 433 434 if (rdma_rcl_chunk_count(ch) > RPCSVC_MAXPAGES) 435 return -EINVAL; 436 437 /* The request is completed when the RDMA_READs complete. The 438 * head context keeps all the pages that comprise the 439 * request. 440 */ 441 head->arg.head[0] = rqstp->rq_arg.head[0]; 442 head->arg.tail[0] = rqstp->rq_arg.tail[0]; 443 head->hdr_count = head->count; 444 head->arg.page_base = 0; 445 head->arg.page_len = 0; 446 head->arg.len = rqstp->rq_arg.len; 447 head->arg.buflen = rqstp->rq_arg.buflen; 448 449 ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; 450 position = be32_to_cpu(ch->rc_position); 451 452 /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */ 453 if (position == 0) { 454 head->arg.pages = &head->pages[0]; 455 page_offset = head->byte_len; 456 } else { 457 head->arg.pages = &head->pages[head->count]; 458 page_offset = 0; 459 } 460 461 ret = 0; 462 page_no = 0; 463 for (; ch->rc_discrim != xdr_zero; ch++) { 464 if (be32_to_cpu(ch->rc_position) != position) 465 goto err; 466 467 handle = be32_to_cpu(ch->rc_target.rs_handle), 468 byte_count = be32_to_cpu(ch->rc_target.rs_length); 469 xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset, 470 &rs_offset); 471 472 while (byte_count > 0) { 473 last = (ch + 1)->rc_discrim == xdr_zero; 474 ret = xprt->sc_reader(xprt, rqstp, head, 475 &page_no, &page_offset, 476 handle, byte_count, 477 rs_offset, last); 478 if (ret < 0) 479 goto err; 480 byte_count -= ret; 481 rs_offset += ret; 482 head->arg.buflen += ret; 483 } 484 } 485 486 /* Read list may need XDR round-up (see RFC 5666, s. 3.7) */ 487 if (page_offset & 3) { 488 u32 pad = 4 - (page_offset & 3); 489 490 head->arg.page_len += pad; 491 head->arg.len += pad; 492 head->arg.buflen += pad; 493 page_offset += pad; 494 } 495 496 ret = 1; 497 if (position && position < head->arg.head[0].iov_len) 498 ret = rdma_copy_tail(rqstp, head, position, 499 byte_count, page_offset, page_no); 500 head->arg.head[0].iov_len = position; 501 head->position = position; 502 503 err: 504 /* Detach arg pages. svc_recv will replenish them */ 505 for (page_no = 0; 506 &rqstp->rq_pages[page_no] < rqstp->rq_respages; page_no++) 507 rqstp->rq_pages[page_no] = NULL; 508 509 return ret; 510 } 511 512 static int rdma_read_complete(struct svc_rqst *rqstp, 513 struct svc_rdma_op_ctxt *head) 514 { 515 int page_no; 516 int ret; 517 518 /* Copy RPC pages */ 519 for (page_no = 0; page_no < head->count; page_no++) { 520 put_page(rqstp->rq_pages[page_no]); 521 rqstp->rq_pages[page_no] = head->pages[page_no]; 522 } 523 524 /* Adjustments made for RDMA_NOMSG type requests */ 525 if (head->position == 0) { 526 if (head->arg.len <= head->sge[0].length) { 527 head->arg.head[0].iov_len = head->arg.len - 528 head->byte_len; 529 head->arg.page_len = 0; 530 } else { 531 head->arg.head[0].iov_len = head->sge[0].length - 532 head->byte_len; 533 head->arg.page_len = head->arg.len - 534 head->sge[0].length; 535 } 536 } 537 538 /* Point rq_arg.pages past header */ 539 rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count]; 540 rqstp->rq_arg.page_len = head->arg.page_len; 541 rqstp->rq_arg.page_base = head->arg.page_base; 542 543 /* rq_respages starts after the last arg page */ 544 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no]; 545 rqstp->rq_next_page = rqstp->rq_respages + 1; 546 547 /* Rebuild rq_arg head and tail. */ 548 rqstp->rq_arg.head[0] = head->arg.head[0]; 549 rqstp->rq_arg.tail[0] = head->arg.tail[0]; 550 rqstp->rq_arg.len = head->arg.len; 551 rqstp->rq_arg.buflen = head->arg.buflen; 552 553 /* Free the context */ 554 svc_rdma_put_context(head, 0); 555 556 /* XXX: What should this be? */ 557 rqstp->rq_prot = IPPROTO_MAX; 558 svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt); 559 560 ret = rqstp->rq_arg.head[0].iov_len 561 + rqstp->rq_arg.page_len 562 + rqstp->rq_arg.tail[0].iov_len; 563 dprintk("svcrdma: deferred read ret=%d, rq_arg.len=%u, " 564 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zu\n", 565 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, 566 rqstp->rq_arg.head[0].iov_len); 567 568 return ret; 569 } 570 571 /* 572 * Set up the rqstp thread context to point to the RQ buffer. If 573 * necessary, pull additional data from the client with an RDMA_READ 574 * request. 575 */ 576 int svc_rdma_recvfrom(struct svc_rqst *rqstp) 577 { 578 struct svc_xprt *xprt = rqstp->rq_xprt; 579 struct svcxprt_rdma *rdma_xprt = 580 container_of(xprt, struct svcxprt_rdma, sc_xprt); 581 struct svc_rdma_op_ctxt *ctxt = NULL; 582 struct rpcrdma_msg *rmsgp; 583 int ret = 0; 584 int len; 585 586 dprintk("svcrdma: rqstp=%p\n", rqstp); 587 588 spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); 589 if (!list_empty(&rdma_xprt->sc_read_complete_q)) { 590 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, 591 struct svc_rdma_op_ctxt, 592 dto_q); 593 list_del_init(&ctxt->dto_q); 594 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); 595 return rdma_read_complete(rqstp, ctxt); 596 } else if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { 597 ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, 598 struct svc_rdma_op_ctxt, 599 dto_q); 600 list_del_init(&ctxt->dto_q); 601 } else { 602 atomic_inc(&rdma_stat_rq_starve); 603 clear_bit(XPT_DATA, &xprt->xpt_flags); 604 ctxt = NULL; 605 } 606 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); 607 if (!ctxt) { 608 /* This is the EAGAIN path. The svc_recv routine will 609 * return -EAGAIN, the nfsd thread will go to call into 610 * svc_recv again and we shouldn't be on the active 611 * transport list 612 */ 613 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) 614 goto close_out; 615 616 goto out; 617 } 618 dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n", 619 ctxt, rdma_xprt, rqstp, ctxt->wc_status); 620 atomic_inc(&rdma_stat_recv); 621 622 /* Build up the XDR from the receive buffers. */ 623 rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len); 624 625 /* Decode the RDMA header. */ 626 len = svc_rdma_xdr_decode_req(&rmsgp, rqstp); 627 rqstp->rq_xprt_hlen = len; 628 629 /* If the request is invalid, reply with an error */ 630 if (len < 0) { 631 if (len == -ENOSYS) 632 svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS); 633 goto close_out; 634 } 635 636 /* Read read-list data. */ 637 ret = rdma_read_chunks(rdma_xprt, rmsgp, rqstp, ctxt); 638 if (ret > 0) { 639 /* read-list posted, defer until data received from client. */ 640 goto defer; 641 } else if (ret < 0) { 642 /* Post of read-list failed, free context. */ 643 svc_rdma_put_context(ctxt, 1); 644 return 0; 645 } 646 647 ret = rqstp->rq_arg.head[0].iov_len 648 + rqstp->rq_arg.page_len 649 + rqstp->rq_arg.tail[0].iov_len; 650 svc_rdma_put_context(ctxt, 0); 651 out: 652 dprintk("svcrdma: ret=%d, rq_arg.len=%u, " 653 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zd\n", 654 ret, rqstp->rq_arg.len, 655 rqstp->rq_arg.head[0].iov_base, 656 rqstp->rq_arg.head[0].iov_len); 657 rqstp->rq_prot = IPPROTO_MAX; 658 svc_xprt_copy_addrs(rqstp, xprt); 659 return ret; 660 661 close_out: 662 if (ctxt) 663 svc_rdma_put_context(ctxt, 1); 664 dprintk("svcrdma: transport %p is closing\n", xprt); 665 /* 666 * Set the close bit and enqueue it. svc_recv will see the 667 * close bit and call svc_xprt_delete 668 */ 669 set_bit(XPT_CLOSE, &xprt->xpt_flags); 670 defer: 671 return 0; 672 } 673