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 * rpc_rdma.c 42 * 43 * This file contains the guts of the RPC RDMA protocol, and 44 * does marshaling/unmarshaling, etc. It is also where interfacing 45 * to the Linux RPC framework lives. 46 */ 47 48 #include "xprt_rdma.h" 49 50 #include <linux/highmem.h> 51 52 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 53 # define RPCDBG_FACILITY RPCDBG_TRANS 54 #endif 55 56 enum rpcrdma_chunktype { 57 rpcrdma_noch = 0, 58 rpcrdma_readch, 59 rpcrdma_areadch, 60 rpcrdma_writech, 61 rpcrdma_replych 62 }; 63 64 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 65 static const char transfertypes[][12] = { 66 "pure inline", /* no chunks */ 67 " read chunk", /* some argument via rdma read */ 68 "*read chunk", /* entire request via rdma read */ 69 "write chunk", /* some result via rdma write */ 70 "reply chunk" /* entire reply via rdma write */ 71 }; 72 #endif 73 74 /* The client can send a request inline as long as the RPCRDMA header 75 * plus the RPC call fit under the transport's inline limit. If the 76 * combined call message size exceeds that limit, the client must use 77 * the read chunk list for this operation. 78 */ 79 static bool rpcrdma_args_inline(struct rpc_rqst *rqst) 80 { 81 unsigned int callsize = RPCRDMA_HDRLEN_MIN + rqst->rq_snd_buf.len; 82 83 return callsize <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst); 84 } 85 86 /* The client can't know how large the actual reply will be. Thus it 87 * plans for the largest possible reply for that particular ULP 88 * operation. If the maximum combined reply message size exceeds that 89 * limit, the client must provide a write list or a reply chunk for 90 * this request. 91 */ 92 static bool rpcrdma_results_inline(struct rpc_rqst *rqst) 93 { 94 unsigned int repsize = RPCRDMA_HDRLEN_MIN + rqst->rq_rcv_buf.buflen; 95 96 return repsize <= RPCRDMA_INLINE_READ_THRESHOLD(rqst); 97 } 98 99 static int 100 rpcrdma_tail_pullup(struct xdr_buf *buf) 101 { 102 size_t tlen = buf->tail[0].iov_len; 103 size_t skip = tlen & 3; 104 105 /* Do not include the tail if it is only an XDR pad */ 106 if (tlen < 4) 107 return 0; 108 109 /* xdr_write_pages() adds a pad at the beginning of the tail 110 * if the content in "buf->pages" is unaligned. Force the 111 * tail's actual content to land at the next XDR position 112 * after the head instead. 113 */ 114 if (skip) { 115 unsigned char *src, *dst; 116 unsigned int count; 117 118 src = buf->tail[0].iov_base; 119 dst = buf->head[0].iov_base; 120 dst += buf->head[0].iov_len; 121 122 src += skip; 123 tlen -= skip; 124 125 dprintk("RPC: %s: skip=%zu, memmove(%p, %p, %zu)\n", 126 __func__, skip, dst, src, tlen); 127 128 for (count = tlen; count; count--) 129 *dst++ = *src++; 130 } 131 132 return tlen; 133 } 134 135 /* Split "vec" on page boundaries into segments. FMR registers pages, 136 * not a byte range. Other modes coalesce these segments into a single 137 * MR when they can. 138 */ 139 static int 140 rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg, 141 int n, int nsegs) 142 { 143 size_t page_offset; 144 u32 remaining; 145 char *base; 146 147 base = vec->iov_base; 148 page_offset = offset_in_page(base); 149 remaining = vec->iov_len; 150 while (remaining && n < nsegs) { 151 seg[n].mr_page = NULL; 152 seg[n].mr_offset = base; 153 seg[n].mr_len = min_t(u32, PAGE_SIZE - page_offset, remaining); 154 remaining -= seg[n].mr_len; 155 base += seg[n].mr_len; 156 ++n; 157 page_offset = 0; 158 } 159 return n; 160 } 161 162 /* 163 * Chunk assembly from upper layer xdr_buf. 164 * 165 * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk 166 * elements. Segments are then coalesced when registered, if possible 167 * within the selected memreg mode. 168 * 169 * Returns positive number of segments converted, or a negative errno. 170 */ 171 172 static int 173 rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos, 174 enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs) 175 { 176 int len, n = 0, p; 177 int page_base; 178 struct page **ppages; 179 180 if (pos == 0) { 181 n = rpcrdma_convert_kvec(&xdrbuf->head[0], seg, n, nsegs); 182 if (n == nsegs) 183 return -EIO; 184 } 185 186 len = xdrbuf->page_len; 187 ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT); 188 page_base = xdrbuf->page_base & ~PAGE_MASK; 189 p = 0; 190 while (len && n < nsegs) { 191 if (!ppages[p]) { 192 /* alloc the pagelist for receiving buffer */ 193 ppages[p] = alloc_page(GFP_ATOMIC); 194 if (!ppages[p]) 195 return -ENOMEM; 196 } 197 seg[n].mr_page = ppages[p]; 198 seg[n].mr_offset = (void *)(unsigned long) page_base; 199 seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len); 200 if (seg[n].mr_len > PAGE_SIZE) 201 return -EIO; 202 len -= seg[n].mr_len; 203 ++n; 204 ++p; 205 page_base = 0; /* page offset only applies to first page */ 206 } 207 208 /* Message overflows the seg array */ 209 if (len && n == nsegs) 210 return -EIO; 211 212 /* When encoding the read list, the tail is always sent inline */ 213 if (type == rpcrdma_readch) 214 return n; 215 216 if (xdrbuf->tail[0].iov_len) { 217 /* the rpcrdma protocol allows us to omit any trailing 218 * xdr pad bytes, saving the server an RDMA operation. */ 219 if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize) 220 return n; 221 n = rpcrdma_convert_kvec(&xdrbuf->tail[0], seg, n, nsegs); 222 if (n == nsegs) 223 return -EIO; 224 } 225 226 return n; 227 } 228 229 /* 230 * Create read/write chunk lists, and reply chunks, for RDMA 231 * 232 * Assume check against THRESHOLD has been done, and chunks are required. 233 * Assume only encoding one list entry for read|write chunks. The NFSv3 234 * protocol is simple enough to allow this as it only has a single "bulk 235 * result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The 236 * RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.) 237 * 238 * When used for a single reply chunk (which is a special write 239 * chunk used for the entire reply, rather than just the data), it 240 * is used primarily for READDIR and READLINK which would otherwise 241 * be severely size-limited by a small rdma inline read max. The server 242 * response will come back as an RDMA Write, followed by a message 243 * of type RDMA_NOMSG carrying the xid and length. As a result, reply 244 * chunks do not provide data alignment, however they do not require 245 * "fixup" (moving the response to the upper layer buffer) either. 246 * 247 * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64): 248 * 249 * Read chunklist (a linked list): 250 * N elements, position P (same P for all chunks of same arg!): 251 * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0 252 * 253 * Write chunklist (a list of (one) counted array): 254 * N elements: 255 * 1 - N - HLOO - HLOO - ... - HLOO - 0 256 * 257 * Reply chunk (a counted array): 258 * N elements: 259 * 1 - N - HLOO - HLOO - ... - HLOO 260 * 261 * Returns positive RPC/RDMA header size, or negative errno. 262 */ 263 264 static ssize_t 265 rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target, 266 struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type) 267 { 268 struct rpcrdma_req *req = rpcr_to_rdmar(rqst); 269 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); 270 int n, nsegs, nchunks = 0; 271 unsigned int pos; 272 struct rpcrdma_mr_seg *seg = req->rl_segments; 273 struct rpcrdma_read_chunk *cur_rchunk = NULL; 274 struct rpcrdma_write_array *warray = NULL; 275 struct rpcrdma_write_chunk *cur_wchunk = NULL; 276 __be32 *iptr = headerp->rm_body.rm_chunks; 277 int (*map)(struct rpcrdma_xprt *, struct rpcrdma_mr_seg *, int, bool); 278 279 if (type == rpcrdma_readch || type == rpcrdma_areadch) { 280 /* a read chunk - server will RDMA Read our memory */ 281 cur_rchunk = (struct rpcrdma_read_chunk *) iptr; 282 } else { 283 /* a write or reply chunk - server will RDMA Write our memory */ 284 *iptr++ = xdr_zero; /* encode a NULL read chunk list */ 285 if (type == rpcrdma_replych) 286 *iptr++ = xdr_zero; /* a NULL write chunk list */ 287 warray = (struct rpcrdma_write_array *) iptr; 288 cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1); 289 } 290 291 if (type == rpcrdma_replych || type == rpcrdma_areadch) 292 pos = 0; 293 else 294 pos = target->head[0].iov_len; 295 296 nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS); 297 if (nsegs < 0) 298 return nsegs; 299 300 map = r_xprt->rx_ia.ri_ops->ro_map; 301 do { 302 n = map(r_xprt, seg, nsegs, cur_wchunk != NULL); 303 if (n <= 0) 304 goto out; 305 if (cur_rchunk) { /* read */ 306 cur_rchunk->rc_discrim = xdr_one; 307 /* all read chunks have the same "position" */ 308 cur_rchunk->rc_position = cpu_to_be32(pos); 309 cur_rchunk->rc_target.rs_handle = 310 cpu_to_be32(seg->mr_rkey); 311 cur_rchunk->rc_target.rs_length = 312 cpu_to_be32(seg->mr_len); 313 xdr_encode_hyper( 314 (__be32 *)&cur_rchunk->rc_target.rs_offset, 315 seg->mr_base); 316 dprintk("RPC: %s: read chunk " 317 "elem %d@0x%llx:0x%x pos %u (%s)\n", __func__, 318 seg->mr_len, (unsigned long long)seg->mr_base, 319 seg->mr_rkey, pos, n < nsegs ? "more" : "last"); 320 cur_rchunk++; 321 r_xprt->rx_stats.read_chunk_count++; 322 } else { /* write/reply */ 323 cur_wchunk->wc_target.rs_handle = 324 cpu_to_be32(seg->mr_rkey); 325 cur_wchunk->wc_target.rs_length = 326 cpu_to_be32(seg->mr_len); 327 xdr_encode_hyper( 328 (__be32 *)&cur_wchunk->wc_target.rs_offset, 329 seg->mr_base); 330 dprintk("RPC: %s: %s chunk " 331 "elem %d@0x%llx:0x%x (%s)\n", __func__, 332 (type == rpcrdma_replych) ? "reply" : "write", 333 seg->mr_len, (unsigned long long)seg->mr_base, 334 seg->mr_rkey, n < nsegs ? "more" : "last"); 335 cur_wchunk++; 336 if (type == rpcrdma_replych) 337 r_xprt->rx_stats.reply_chunk_count++; 338 else 339 r_xprt->rx_stats.write_chunk_count++; 340 r_xprt->rx_stats.total_rdma_request += seg->mr_len; 341 } 342 nchunks++; 343 seg += n; 344 nsegs -= n; 345 } while (nsegs); 346 347 /* success. all failures return above */ 348 req->rl_nchunks = nchunks; 349 350 /* 351 * finish off header. If write, marshal discrim and nchunks. 352 */ 353 if (cur_rchunk) { 354 iptr = (__be32 *) cur_rchunk; 355 *iptr++ = xdr_zero; /* finish the read chunk list */ 356 *iptr++ = xdr_zero; /* encode a NULL write chunk list */ 357 *iptr++ = xdr_zero; /* encode a NULL reply chunk */ 358 } else { 359 warray->wc_discrim = xdr_one; 360 warray->wc_nchunks = cpu_to_be32(nchunks); 361 iptr = (__be32 *) cur_wchunk; 362 if (type == rpcrdma_writech) { 363 *iptr++ = xdr_zero; /* finish the write chunk list */ 364 *iptr++ = xdr_zero; /* encode a NULL reply chunk */ 365 } 366 } 367 368 /* 369 * Return header size. 370 */ 371 return (unsigned char *)iptr - (unsigned char *)headerp; 372 373 out: 374 for (pos = 0; nchunks--;) 375 pos += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt, 376 &req->rl_segments[pos]); 377 return n; 378 } 379 380 /* 381 * Copy write data inline. 382 * This function is used for "small" requests. Data which is passed 383 * to RPC via iovecs (or page list) is copied directly into the 384 * pre-registered memory buffer for this request. For small amounts 385 * of data, this is efficient. The cutoff value is tunable. 386 */ 387 static void rpcrdma_inline_pullup(struct rpc_rqst *rqst) 388 { 389 int i, npages, curlen; 390 int copy_len; 391 unsigned char *srcp, *destp; 392 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt); 393 int page_base; 394 struct page **ppages; 395 396 destp = rqst->rq_svec[0].iov_base; 397 curlen = rqst->rq_svec[0].iov_len; 398 destp += curlen; 399 400 dprintk("RPC: %s: destp 0x%p len %d hdrlen %d\n", 401 __func__, destp, rqst->rq_slen, curlen); 402 403 copy_len = rqst->rq_snd_buf.page_len; 404 405 if (rqst->rq_snd_buf.tail[0].iov_len) { 406 curlen = rqst->rq_snd_buf.tail[0].iov_len; 407 if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) { 408 memmove(destp + copy_len, 409 rqst->rq_snd_buf.tail[0].iov_base, curlen); 410 r_xprt->rx_stats.pullup_copy_count += curlen; 411 } 412 dprintk("RPC: %s: tail destp 0x%p len %d\n", 413 __func__, destp + copy_len, curlen); 414 rqst->rq_svec[0].iov_len += curlen; 415 } 416 r_xprt->rx_stats.pullup_copy_count += copy_len; 417 418 page_base = rqst->rq_snd_buf.page_base; 419 ppages = rqst->rq_snd_buf.pages + (page_base >> PAGE_SHIFT); 420 page_base &= ~PAGE_MASK; 421 npages = PAGE_ALIGN(page_base+copy_len) >> PAGE_SHIFT; 422 for (i = 0; copy_len && i < npages; i++) { 423 curlen = PAGE_SIZE - page_base; 424 if (curlen > copy_len) 425 curlen = copy_len; 426 dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n", 427 __func__, i, destp, copy_len, curlen); 428 srcp = kmap_atomic(ppages[i]); 429 memcpy(destp, srcp+page_base, curlen); 430 kunmap_atomic(srcp); 431 rqst->rq_svec[0].iov_len += curlen; 432 destp += curlen; 433 copy_len -= curlen; 434 page_base = 0; 435 } 436 /* header now contains entire send message */ 437 } 438 439 /* 440 * Marshal a request: the primary job of this routine is to choose 441 * the transfer modes. See comments below. 442 * 443 * Uses multiple RDMA IOVs for a request: 444 * [0] -- RPC RDMA header, which uses memory from the *start* of the 445 * preregistered buffer that already holds the RPC data in 446 * its middle. 447 * [1] -- the RPC header/data, marshaled by RPC and the NFS protocol. 448 * [2] -- optional padding. 449 * [3] -- if padded, header only in [1] and data here. 450 * 451 * Returns zero on success, otherwise a negative errno. 452 */ 453 454 int 455 rpcrdma_marshal_req(struct rpc_rqst *rqst) 456 { 457 struct rpc_xprt *xprt = rqst->rq_xprt; 458 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt); 459 struct rpcrdma_req *req = rpcr_to_rdmar(rqst); 460 char *base; 461 size_t rpclen; 462 ssize_t hdrlen; 463 enum rpcrdma_chunktype rtype, wtype; 464 struct rpcrdma_msg *headerp; 465 466 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 467 if (test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state)) 468 return rpcrdma_bc_marshal_reply(rqst); 469 #endif 470 471 /* 472 * rpclen gets amount of data in first buffer, which is the 473 * pre-registered buffer. 474 */ 475 base = rqst->rq_svec[0].iov_base; 476 rpclen = rqst->rq_svec[0].iov_len; 477 478 headerp = rdmab_to_msg(req->rl_rdmabuf); 479 /* don't byte-swap XID, it's already done in request */ 480 headerp->rm_xid = rqst->rq_xid; 481 headerp->rm_vers = rpcrdma_version; 482 headerp->rm_credit = cpu_to_be32(r_xprt->rx_buf.rb_max_requests); 483 headerp->rm_type = rdma_msg; 484 485 /* 486 * Chunks needed for results? 487 * 488 * o Read ops return data as write chunk(s), header as inline. 489 * o If the expected result is under the inline threshold, all ops 490 * return as inline. 491 * o Large non-read ops return as a single reply chunk. 492 */ 493 if (rqst->rq_rcv_buf.flags & XDRBUF_READ) 494 wtype = rpcrdma_writech; 495 else if (rpcrdma_results_inline(rqst)) 496 wtype = rpcrdma_noch; 497 else 498 wtype = rpcrdma_replych; 499 500 /* 501 * Chunks needed for arguments? 502 * 503 * o If the total request is under the inline threshold, all ops 504 * are sent as inline. 505 * o Large write ops transmit data as read chunk(s), header as 506 * inline. 507 * o Large non-write ops are sent with the entire message as a 508 * single read chunk (protocol 0-position special case). 509 * 510 * This assumes that the upper layer does not present a request 511 * that both has a data payload, and whose non-data arguments 512 * by themselves are larger than the inline threshold. 513 */ 514 if (rpcrdma_args_inline(rqst)) { 515 rtype = rpcrdma_noch; 516 } else if (rqst->rq_snd_buf.flags & XDRBUF_WRITE) { 517 rtype = rpcrdma_readch; 518 } else { 519 r_xprt->rx_stats.nomsg_call_count++; 520 headerp->rm_type = htonl(RDMA_NOMSG); 521 rtype = rpcrdma_areadch; 522 rpclen = 0; 523 } 524 525 /* The following simplification is not true forever */ 526 if (rtype != rpcrdma_noch && wtype == rpcrdma_replych) 527 wtype = rpcrdma_noch; 528 if (rtype != rpcrdma_noch && wtype != rpcrdma_noch) { 529 dprintk("RPC: %s: cannot marshal multiple chunk lists\n", 530 __func__); 531 return -EIO; 532 } 533 534 hdrlen = RPCRDMA_HDRLEN_MIN; 535 536 /* 537 * Pull up any extra send data into the preregistered buffer. 538 * When padding is in use and applies to the transfer, insert 539 * it and change the message type. 540 */ 541 if (rtype == rpcrdma_noch) { 542 543 rpcrdma_inline_pullup(rqst); 544 545 headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero; 546 headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero; 547 headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero; 548 /* new length after pullup */ 549 rpclen = rqst->rq_svec[0].iov_len; 550 } else if (rtype == rpcrdma_readch) 551 rpclen += rpcrdma_tail_pullup(&rqst->rq_snd_buf); 552 if (rtype != rpcrdma_noch) { 553 hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_snd_buf, 554 headerp, rtype); 555 wtype = rtype; /* simplify dprintk */ 556 557 } else if (wtype != rpcrdma_noch) { 558 hdrlen = rpcrdma_create_chunks(rqst, &rqst->rq_rcv_buf, 559 headerp, wtype); 560 } 561 if (hdrlen < 0) 562 return hdrlen; 563 564 dprintk("RPC: %s: %s: hdrlen %zd rpclen %zd" 565 " headerp 0x%p base 0x%p lkey 0x%x\n", 566 __func__, transfertypes[wtype], hdrlen, rpclen, 567 headerp, base, rdmab_lkey(req->rl_rdmabuf)); 568 569 /* 570 * initialize send_iov's - normally only two: rdma chunk header and 571 * single preregistered RPC header buffer, but if padding is present, 572 * then use a preregistered (and zeroed) pad buffer between the RPC 573 * header and any write data. In all non-rdma cases, any following 574 * data has been copied into the RPC header buffer. 575 */ 576 req->rl_send_iov[0].addr = rdmab_addr(req->rl_rdmabuf); 577 req->rl_send_iov[0].length = hdrlen; 578 req->rl_send_iov[0].lkey = rdmab_lkey(req->rl_rdmabuf); 579 580 req->rl_niovs = 1; 581 if (rtype == rpcrdma_areadch) 582 return 0; 583 584 req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf); 585 req->rl_send_iov[1].length = rpclen; 586 req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf); 587 588 req->rl_niovs = 2; 589 return 0; 590 } 591 592 /* 593 * Chase down a received write or reply chunklist to get length 594 * RDMA'd by server. See map at rpcrdma_create_chunks()! :-) 595 */ 596 static int 597 rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp) 598 { 599 unsigned int i, total_len; 600 struct rpcrdma_write_chunk *cur_wchunk; 601 char *base = (char *)rdmab_to_msg(rep->rr_rdmabuf); 602 603 i = be32_to_cpu(**iptrp); 604 if (i > max) 605 return -1; 606 cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1); 607 total_len = 0; 608 while (i--) { 609 struct rpcrdma_segment *seg = &cur_wchunk->wc_target; 610 ifdebug(FACILITY) { 611 u64 off; 612 xdr_decode_hyper((__be32 *)&seg->rs_offset, &off); 613 dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n", 614 __func__, 615 be32_to_cpu(seg->rs_length), 616 (unsigned long long)off, 617 be32_to_cpu(seg->rs_handle)); 618 } 619 total_len += be32_to_cpu(seg->rs_length); 620 ++cur_wchunk; 621 } 622 /* check and adjust for properly terminated write chunk */ 623 if (wrchunk) { 624 __be32 *w = (__be32 *) cur_wchunk; 625 if (*w++ != xdr_zero) 626 return -1; 627 cur_wchunk = (struct rpcrdma_write_chunk *) w; 628 } 629 if ((char *)cur_wchunk > base + rep->rr_len) 630 return -1; 631 632 *iptrp = (__be32 *) cur_wchunk; 633 return total_len; 634 } 635 636 /* 637 * Scatter inline received data back into provided iov's. 638 */ 639 static void 640 rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad) 641 { 642 int i, npages, curlen, olen; 643 char *destp; 644 struct page **ppages; 645 int page_base; 646 647 curlen = rqst->rq_rcv_buf.head[0].iov_len; 648 if (curlen > copy_len) { /* write chunk header fixup */ 649 curlen = copy_len; 650 rqst->rq_rcv_buf.head[0].iov_len = curlen; 651 } 652 653 dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n", 654 __func__, srcp, copy_len, curlen); 655 656 /* Shift pointer for first receive segment only */ 657 rqst->rq_rcv_buf.head[0].iov_base = srcp; 658 srcp += curlen; 659 copy_len -= curlen; 660 661 olen = copy_len; 662 i = 0; 663 rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen; 664 page_base = rqst->rq_rcv_buf.page_base; 665 ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT); 666 page_base &= ~PAGE_MASK; 667 668 if (copy_len && rqst->rq_rcv_buf.page_len) { 669 npages = PAGE_ALIGN(page_base + 670 rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT; 671 for (; i < npages; i++) { 672 curlen = PAGE_SIZE - page_base; 673 if (curlen > copy_len) 674 curlen = copy_len; 675 dprintk("RPC: %s: page %d" 676 " srcp 0x%p len %d curlen %d\n", 677 __func__, i, srcp, copy_len, curlen); 678 destp = kmap_atomic(ppages[i]); 679 memcpy(destp + page_base, srcp, curlen); 680 flush_dcache_page(ppages[i]); 681 kunmap_atomic(destp); 682 srcp += curlen; 683 copy_len -= curlen; 684 if (copy_len == 0) 685 break; 686 page_base = 0; 687 } 688 } 689 690 if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) { 691 curlen = copy_len; 692 if (curlen > rqst->rq_rcv_buf.tail[0].iov_len) 693 curlen = rqst->rq_rcv_buf.tail[0].iov_len; 694 if (rqst->rq_rcv_buf.tail[0].iov_base != srcp) 695 memmove(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen); 696 dprintk("RPC: %s: tail srcp 0x%p len %d curlen %d\n", 697 __func__, srcp, copy_len, curlen); 698 rqst->rq_rcv_buf.tail[0].iov_len = curlen; 699 copy_len -= curlen; ++i; 700 } else 701 rqst->rq_rcv_buf.tail[0].iov_len = 0; 702 703 if (pad) { 704 /* implicit padding on terminal chunk */ 705 unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base; 706 while (pad--) 707 p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0; 708 } 709 710 if (copy_len) 711 dprintk("RPC: %s: %d bytes in" 712 " %d extra segments (%d lost)\n", 713 __func__, olen, i, copy_len); 714 715 /* TBD avoid a warning from call_decode() */ 716 rqst->rq_private_buf = rqst->rq_rcv_buf; 717 } 718 719 void 720 rpcrdma_connect_worker(struct work_struct *work) 721 { 722 struct rpcrdma_ep *ep = 723 container_of(work, struct rpcrdma_ep, rep_connect_worker.work); 724 struct rpcrdma_xprt *r_xprt = 725 container_of(ep, struct rpcrdma_xprt, rx_ep); 726 struct rpc_xprt *xprt = &r_xprt->rx_xprt; 727 728 spin_lock_bh(&xprt->transport_lock); 729 if (++xprt->connect_cookie == 0) /* maintain a reserved value */ 730 ++xprt->connect_cookie; 731 if (ep->rep_connected > 0) { 732 if (!xprt_test_and_set_connected(xprt)) 733 xprt_wake_pending_tasks(xprt, 0); 734 } else { 735 if (xprt_test_and_clear_connected(xprt)) 736 xprt_wake_pending_tasks(xprt, -ENOTCONN); 737 } 738 spin_unlock_bh(&xprt->transport_lock); 739 } 740 741 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 742 /* By convention, backchannel calls arrive via rdma_msg type 743 * messages, and never populate the chunk lists. This makes 744 * the RPC/RDMA header small and fixed in size, so it is 745 * straightforward to check the RPC header's direction field. 746 */ 747 static bool 748 rpcrdma_is_bcall(struct rpcrdma_msg *headerp) 749 { 750 __be32 *p = (__be32 *)headerp; 751 752 if (headerp->rm_type != rdma_msg) 753 return false; 754 if (headerp->rm_body.rm_chunks[0] != xdr_zero) 755 return false; 756 if (headerp->rm_body.rm_chunks[1] != xdr_zero) 757 return false; 758 if (headerp->rm_body.rm_chunks[2] != xdr_zero) 759 return false; 760 761 /* sanity */ 762 if (p[7] != headerp->rm_xid) 763 return false; 764 /* call direction */ 765 if (p[8] != cpu_to_be32(RPC_CALL)) 766 return false; 767 768 return true; 769 } 770 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 771 772 /* 773 * This function is called when an async event is posted to 774 * the connection which changes the connection state. All it 775 * does at this point is mark the connection up/down, the rpc 776 * timers do the rest. 777 */ 778 void 779 rpcrdma_conn_func(struct rpcrdma_ep *ep) 780 { 781 schedule_delayed_work(&ep->rep_connect_worker, 0); 782 } 783 784 /* Process received RPC/RDMA messages. 785 * 786 * Errors must result in the RPC task either being awakened, or 787 * allowed to timeout, to discover the errors at that time. 788 */ 789 void 790 rpcrdma_reply_handler(struct rpcrdma_rep *rep) 791 { 792 struct rpcrdma_msg *headerp; 793 struct rpcrdma_req *req; 794 struct rpc_rqst *rqst; 795 struct rpcrdma_xprt *r_xprt = rep->rr_rxprt; 796 struct rpc_xprt *xprt = &r_xprt->rx_xprt; 797 __be32 *iptr; 798 int rdmalen, status, rmerr; 799 unsigned long cwnd; 800 801 dprintk("RPC: %s: incoming rep %p\n", __func__, rep); 802 803 if (rep->rr_len == RPCRDMA_BAD_LEN) 804 goto out_badstatus; 805 if (rep->rr_len < RPCRDMA_HDRLEN_ERR) 806 goto out_shortreply; 807 808 headerp = rdmab_to_msg(rep->rr_rdmabuf); 809 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 810 if (rpcrdma_is_bcall(headerp)) 811 goto out_bcall; 812 #endif 813 814 /* Match incoming rpcrdma_rep to an rpcrdma_req to 815 * get context for handling any incoming chunks. 816 */ 817 spin_lock_bh(&xprt->transport_lock); 818 rqst = xprt_lookup_rqst(xprt, headerp->rm_xid); 819 if (!rqst) 820 goto out_nomatch; 821 822 req = rpcr_to_rdmar(rqst); 823 if (req->rl_reply) 824 goto out_duplicate; 825 826 /* Sanity checking has passed. We are now committed 827 * to complete this transaction. 828 */ 829 list_del_init(&rqst->rq_list); 830 spin_unlock_bh(&xprt->transport_lock); 831 dprintk("RPC: %s: reply %p completes request %p (xid 0x%08x)\n", 832 __func__, rep, req, be32_to_cpu(headerp->rm_xid)); 833 834 /* from here on, the reply is no longer an orphan */ 835 req->rl_reply = rep; 836 xprt->reestablish_timeout = 0; 837 838 if (headerp->rm_vers != rpcrdma_version) 839 goto out_badversion; 840 841 /* check for expected message types */ 842 /* The order of some of these tests is important. */ 843 switch (headerp->rm_type) { 844 case rdma_msg: 845 /* never expect read chunks */ 846 /* never expect reply chunks (two ways to check) */ 847 /* never expect write chunks without having offered RDMA */ 848 if (headerp->rm_body.rm_chunks[0] != xdr_zero || 849 (headerp->rm_body.rm_chunks[1] == xdr_zero && 850 headerp->rm_body.rm_chunks[2] != xdr_zero) || 851 (headerp->rm_body.rm_chunks[1] != xdr_zero && 852 req->rl_nchunks == 0)) 853 goto badheader; 854 if (headerp->rm_body.rm_chunks[1] != xdr_zero) { 855 /* count any expected write chunks in read reply */ 856 /* start at write chunk array count */ 857 iptr = &headerp->rm_body.rm_chunks[2]; 858 rdmalen = rpcrdma_count_chunks(rep, 859 req->rl_nchunks, 1, &iptr); 860 /* check for validity, and no reply chunk after */ 861 if (rdmalen < 0 || *iptr++ != xdr_zero) 862 goto badheader; 863 rep->rr_len -= 864 ((unsigned char *)iptr - (unsigned char *)headerp); 865 status = rep->rr_len + rdmalen; 866 r_xprt->rx_stats.total_rdma_reply += rdmalen; 867 /* special case - last chunk may omit padding */ 868 if (rdmalen &= 3) { 869 rdmalen = 4 - rdmalen; 870 status += rdmalen; 871 } 872 } else { 873 /* else ordinary inline */ 874 rdmalen = 0; 875 iptr = (__be32 *)((unsigned char *)headerp + 876 RPCRDMA_HDRLEN_MIN); 877 rep->rr_len -= RPCRDMA_HDRLEN_MIN; 878 status = rep->rr_len; 879 } 880 /* Fix up the rpc results for upper layer */ 881 rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen); 882 break; 883 884 case rdma_nomsg: 885 /* never expect read or write chunks, always reply chunks */ 886 if (headerp->rm_body.rm_chunks[0] != xdr_zero || 887 headerp->rm_body.rm_chunks[1] != xdr_zero || 888 headerp->rm_body.rm_chunks[2] != xdr_one || 889 req->rl_nchunks == 0) 890 goto badheader; 891 iptr = (__be32 *)((unsigned char *)headerp + 892 RPCRDMA_HDRLEN_MIN); 893 rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr); 894 if (rdmalen < 0) 895 goto badheader; 896 r_xprt->rx_stats.total_rdma_reply += rdmalen; 897 /* Reply chunk buffer already is the reply vector - no fixup. */ 898 status = rdmalen; 899 break; 900 901 case rdma_error: 902 goto out_rdmaerr; 903 904 badheader: 905 default: 906 dprintk("%s: invalid rpcrdma reply header (type %d):" 907 " chunks[012] == %d %d %d" 908 " expected chunks <= %d\n", 909 __func__, be32_to_cpu(headerp->rm_type), 910 headerp->rm_body.rm_chunks[0], 911 headerp->rm_body.rm_chunks[1], 912 headerp->rm_body.rm_chunks[2], 913 req->rl_nchunks); 914 status = -EIO; 915 r_xprt->rx_stats.bad_reply_count++; 916 break; 917 } 918 919 out: 920 /* Invalidate and flush the data payloads before waking the 921 * waiting application. This guarantees the memory region is 922 * properly fenced from the server before the application 923 * accesses the data. It also ensures proper send flow 924 * control: waking the next RPC waits until this RPC has 925 * relinquished all its Send Queue entries. 926 */ 927 if (req->rl_nchunks) 928 r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, req); 929 930 spin_lock_bh(&xprt->transport_lock); 931 cwnd = xprt->cwnd; 932 xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT; 933 if (xprt->cwnd > cwnd) 934 xprt_release_rqst_cong(rqst->rq_task); 935 936 xprt_complete_rqst(rqst->rq_task, status); 937 spin_unlock_bh(&xprt->transport_lock); 938 dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n", 939 __func__, xprt, rqst, status); 940 return; 941 942 out_badstatus: 943 rpcrdma_recv_buffer_put(rep); 944 if (r_xprt->rx_ep.rep_connected == 1) { 945 r_xprt->rx_ep.rep_connected = -EIO; 946 rpcrdma_conn_func(&r_xprt->rx_ep); 947 } 948 return; 949 950 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 951 out_bcall: 952 rpcrdma_bc_receive_call(r_xprt, rep); 953 return; 954 #endif 955 956 /* If the incoming reply terminated a pending RPC, the next 957 * RPC call will post a replacement receive buffer as it is 958 * being marshaled. 959 */ 960 out_badversion: 961 dprintk("RPC: %s: invalid version %d\n", 962 __func__, be32_to_cpu(headerp->rm_vers)); 963 status = -EIO; 964 r_xprt->rx_stats.bad_reply_count++; 965 goto out; 966 967 out_rdmaerr: 968 rmerr = be32_to_cpu(headerp->rm_body.rm_error.rm_err); 969 switch (rmerr) { 970 case ERR_VERS: 971 pr_err("%s: server reports header version error (%u-%u)\n", 972 __func__, 973 be32_to_cpu(headerp->rm_body.rm_error.rm_vers_low), 974 be32_to_cpu(headerp->rm_body.rm_error.rm_vers_high)); 975 break; 976 case ERR_CHUNK: 977 pr_err("%s: server reports header decoding error\n", 978 __func__); 979 break; 980 default: 981 pr_err("%s: server reports unknown error %d\n", 982 __func__, rmerr); 983 } 984 status = -EREMOTEIO; 985 r_xprt->rx_stats.bad_reply_count++; 986 goto out; 987 988 /* If no pending RPC transaction was matched, post a replacement 989 * receive buffer before returning. 990 */ 991 out_shortreply: 992 dprintk("RPC: %s: short/invalid reply\n", __func__); 993 goto repost; 994 995 out_nomatch: 996 spin_unlock_bh(&xprt->transport_lock); 997 dprintk("RPC: %s: no match for incoming xid 0x%08x len %d\n", 998 __func__, be32_to_cpu(headerp->rm_xid), 999 rep->rr_len); 1000 goto repost; 1001 1002 out_duplicate: 1003 spin_unlock_bh(&xprt->transport_lock); 1004 dprintk("RPC: %s: " 1005 "duplicate reply %p to RPC request %p: xid 0x%08x\n", 1006 __func__, rep, req, be32_to_cpu(headerp->rm_xid)); 1007 1008 repost: 1009 r_xprt->rx_stats.bad_reply_count++; 1010 if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep)) 1011 rpcrdma_recv_buffer_put(rep); 1012 } 1013