/net/sunrpc/xprtrdma/rpc_rdma.c
C | 882 lines | 562 code | 83 blank | 237 comment | 158 complexity | 7033242f6335c194a7e0c92a8e8d8b5c MD5 | raw file
Possible License(s): CC-BY-SA-3.0, GPL-2.0, LGPL-2.0, AGPL-1.0
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#ifdef RPC_DEBUG
53# define RPCDBG_FACILITY RPCDBG_TRANS
54#endif
55
56enum rpcrdma_chunktype {
57 rpcrdma_noch = 0,
58 rpcrdma_readch,
59 rpcrdma_areadch,
60 rpcrdma_writech,
61 rpcrdma_replych
62};
63
64#ifdef RPC_DEBUG
65static 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/*
75 * Chunk assembly from upper layer xdr_buf.
76 *
77 * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
78 * elements. Segments are then coalesced when registered, if possible
79 * within the selected memreg mode.
80 *
81 * Note, this routine is never called if the connection's memory
82 * registration strategy is 0 (bounce buffers).
83 */
84
85static int
86rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, unsigned int pos,
87 enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
88{
89 int len, n = 0, p;
90
91 if (pos == 0 && xdrbuf->head[0].iov_len) {
92 seg[n].mr_page = NULL;
93 seg[n].mr_offset = xdrbuf->head[0].iov_base;
94 seg[n].mr_len = xdrbuf->head[0].iov_len;
95 ++n;
96 }
97
98 if (xdrbuf->page_len && (xdrbuf->pages[0] != NULL)) {
99 if (n == nsegs)
100 return 0;
101 seg[n].mr_page = xdrbuf->pages[0];
102 seg[n].mr_offset = (void *)(unsigned long) xdrbuf->page_base;
103 seg[n].mr_len = min_t(u32,
104 PAGE_SIZE - xdrbuf->page_base, xdrbuf->page_len);
105 len = xdrbuf->page_len - seg[n].mr_len;
106 ++n;
107 p = 1;
108 while (len > 0) {
109 if (n == nsegs)
110 return 0;
111 seg[n].mr_page = xdrbuf->pages[p];
112 seg[n].mr_offset = NULL;
113 seg[n].mr_len = min_t(u32, PAGE_SIZE, len);
114 len -= seg[n].mr_len;
115 ++n;
116 ++p;
117 }
118 }
119
120 if (xdrbuf->tail[0].iov_len) {
121 /* the rpcrdma protocol allows us to omit any trailing
122 * xdr pad bytes, saving the server an RDMA operation. */
123 if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
124 return n;
125 if (n == nsegs)
126 return 0;
127 seg[n].mr_page = NULL;
128 seg[n].mr_offset = xdrbuf->tail[0].iov_base;
129 seg[n].mr_len = xdrbuf->tail[0].iov_len;
130 ++n;
131 }
132
133 return n;
134}
135
136/*
137 * Create read/write chunk lists, and reply chunks, for RDMA
138 *
139 * Assume check against THRESHOLD has been done, and chunks are required.
140 * Assume only encoding one list entry for read|write chunks. The NFSv3
141 * protocol is simple enough to allow this as it only has a single "bulk
142 * result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The
143 * RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.)
144 *
145 * When used for a single reply chunk (which is a special write
146 * chunk used for the entire reply, rather than just the data), it
147 * is used primarily for READDIR and READLINK which would otherwise
148 * be severely size-limited by a small rdma inline read max. The server
149 * response will come back as an RDMA Write, followed by a message
150 * of type RDMA_NOMSG carrying the xid and length. As a result, reply
151 * chunks do not provide data alignment, however they do not require
152 * "fixup" (moving the response to the upper layer buffer) either.
153 *
154 * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
155 *
156 * Read chunklist (a linked list):
157 * N elements, position P (same P for all chunks of same arg!):
158 * 1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
159 *
160 * Write chunklist (a list of (one) counted array):
161 * N elements:
162 * 1 - N - HLOO - HLOO - ... - HLOO - 0
163 *
164 * Reply chunk (a counted array):
165 * N elements:
166 * 1 - N - HLOO - HLOO - ... - HLOO
167 */
168
169static unsigned int
170rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
171 struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type)
172{
173 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
174 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_task->tk_xprt);
175 int nsegs, nchunks = 0;
176 unsigned int pos;
177 struct rpcrdma_mr_seg *seg = req->rl_segments;
178 struct rpcrdma_read_chunk *cur_rchunk = NULL;
179 struct rpcrdma_write_array *warray = NULL;
180 struct rpcrdma_write_chunk *cur_wchunk = NULL;
181 __be32 *iptr = headerp->rm_body.rm_chunks;
182
183 if (type == rpcrdma_readch || type == rpcrdma_areadch) {
184 /* a read chunk - server will RDMA Read our memory */
185 cur_rchunk = (struct rpcrdma_read_chunk *) iptr;
186 } else {
187 /* a write or reply chunk - server will RDMA Write our memory */
188 *iptr++ = xdr_zero; /* encode a NULL read chunk list */
189 if (type == rpcrdma_replych)
190 *iptr++ = xdr_zero; /* a NULL write chunk list */
191 warray = (struct rpcrdma_write_array *) iptr;
192 cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1);
193 }
194
195 if (type == rpcrdma_replych || type == rpcrdma_areadch)
196 pos = 0;
197 else
198 pos = target->head[0].iov_len;
199
200 nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS);
201 if (nsegs == 0)
202 return 0;
203
204 do {
205 /* bind/register the memory, then build chunk from result. */
206 int n = rpcrdma_register_external(seg, nsegs,
207 cur_wchunk != NULL, r_xprt);
208 if (n <= 0)
209 goto out;
210 if (cur_rchunk) { /* read */
211 cur_rchunk->rc_discrim = xdr_one;
212 /* all read chunks have the same "position" */
213 cur_rchunk->rc_position = htonl(pos);
214 cur_rchunk->rc_target.rs_handle = htonl(seg->mr_rkey);
215 cur_rchunk->rc_target.rs_length = htonl(seg->mr_len);
216 xdr_encode_hyper(
217 (__be32 *)&cur_rchunk->rc_target.rs_offset,
218 seg->mr_base);
219 dprintk("RPC: %s: read chunk "
220 "elem %d@0x%llx:0x%x pos %u (%s)\n", __func__,
221 seg->mr_len, (unsigned long long)seg->mr_base,
222 seg->mr_rkey, pos, n < nsegs ? "more" : "last");
223 cur_rchunk++;
224 r_xprt->rx_stats.read_chunk_count++;
225 } else { /* write/reply */
226 cur_wchunk->wc_target.rs_handle = htonl(seg->mr_rkey);
227 cur_wchunk->wc_target.rs_length = htonl(seg->mr_len);
228 xdr_encode_hyper(
229 (__be32 *)&cur_wchunk->wc_target.rs_offset,
230 seg->mr_base);
231 dprintk("RPC: %s: %s chunk "
232 "elem %d@0x%llx:0x%x (%s)\n", __func__,
233 (type == rpcrdma_replych) ? "reply" : "write",
234 seg->mr_len, (unsigned long long)seg->mr_base,
235 seg->mr_rkey, n < nsegs ? "more" : "last");
236 cur_wchunk++;
237 if (type == rpcrdma_replych)
238 r_xprt->rx_stats.reply_chunk_count++;
239 else
240 r_xprt->rx_stats.write_chunk_count++;
241 r_xprt->rx_stats.total_rdma_request += seg->mr_len;
242 }
243 nchunks++;
244 seg += n;
245 nsegs -= n;
246 } while (nsegs);
247
248 /* success. all failures return above */
249 req->rl_nchunks = nchunks;
250
251 BUG_ON(nchunks == 0);
252
253 /*
254 * finish off header. If write, marshal discrim and nchunks.
255 */
256 if (cur_rchunk) {
257 iptr = (__be32 *) cur_rchunk;
258 *iptr++ = xdr_zero; /* finish the read chunk list */
259 *iptr++ = xdr_zero; /* encode a NULL write chunk list */
260 *iptr++ = xdr_zero; /* encode a NULL reply chunk */
261 } else {
262 warray->wc_discrim = xdr_one;
263 warray->wc_nchunks = htonl(nchunks);
264 iptr = (__be32 *) cur_wchunk;
265 if (type == rpcrdma_writech) {
266 *iptr++ = xdr_zero; /* finish the write chunk list */
267 *iptr++ = xdr_zero; /* encode a NULL reply chunk */
268 }
269 }
270
271 /*
272 * Return header size.
273 */
274 return (unsigned char *)iptr - (unsigned char *)headerp;
275
276out:
277 for (pos = 0; nchunks--;)
278 pos += rpcrdma_deregister_external(
279 &req->rl_segments[pos], r_xprt, NULL);
280 return 0;
281}
282
283/*
284 * Copy write data inline.
285 * This function is used for "small" requests. Data which is passed
286 * to RPC via iovecs (or page list) is copied directly into the
287 * pre-registered memory buffer for this request. For small amounts
288 * of data, this is efficient. The cutoff value is tunable.
289 */
290static int
291rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
292{
293 int i, npages, curlen;
294 int copy_len;
295 unsigned char *srcp, *destp;
296 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
297
298 destp = rqst->rq_svec[0].iov_base;
299 curlen = rqst->rq_svec[0].iov_len;
300 destp += curlen;
301 /*
302 * Do optional padding where it makes sense. Alignment of write
303 * payload can help the server, if our setting is accurate.
304 */
305 pad -= (curlen + 36/*sizeof(struct rpcrdma_msg_padded)*/);
306 if (pad < 0 || rqst->rq_slen - curlen < RPCRDMA_INLINE_PAD_THRESH)
307 pad = 0; /* don't pad this request */
308
309 dprintk("RPC: %s: pad %d destp 0x%p len %d hdrlen %d\n",
310 __func__, pad, destp, rqst->rq_slen, curlen);
311
312 copy_len = rqst->rq_snd_buf.page_len;
313
314 if (rqst->rq_snd_buf.tail[0].iov_len) {
315 curlen = rqst->rq_snd_buf.tail[0].iov_len;
316 if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) {
317 memmove(destp + copy_len,
318 rqst->rq_snd_buf.tail[0].iov_base, curlen);
319 r_xprt->rx_stats.pullup_copy_count += curlen;
320 }
321 dprintk("RPC: %s: tail destp 0x%p len %d\n",
322 __func__, destp + copy_len, curlen);
323 rqst->rq_svec[0].iov_len += curlen;
324 }
325
326 r_xprt->rx_stats.pullup_copy_count += copy_len;
327 npages = PAGE_ALIGN(rqst->rq_snd_buf.page_base+copy_len) >> PAGE_SHIFT;
328 for (i = 0; copy_len && i < npages; i++) {
329 if (i == 0)
330 curlen = PAGE_SIZE - rqst->rq_snd_buf.page_base;
331 else
332 curlen = PAGE_SIZE;
333 if (curlen > copy_len)
334 curlen = copy_len;
335 dprintk("RPC: %s: page %d destp 0x%p len %d curlen %d\n",
336 __func__, i, destp, copy_len, curlen);
337 srcp = kmap_atomic(rqst->rq_snd_buf.pages[i],
338 KM_SKB_SUNRPC_DATA);
339 if (i == 0)
340 memcpy(destp, srcp+rqst->rq_snd_buf.page_base, curlen);
341 else
342 memcpy(destp, srcp, curlen);
343 kunmap_atomic(srcp, KM_SKB_SUNRPC_DATA);
344 rqst->rq_svec[0].iov_len += curlen;
345 destp += curlen;
346 copy_len -= curlen;
347 }
348 /* header now contains entire send message */
349 return pad;
350}
351
352/*
353 * Marshal a request: the primary job of this routine is to choose
354 * the transfer modes. See comments below.
355 *
356 * Uses multiple RDMA IOVs for a request:
357 * [0] -- RPC RDMA header, which uses memory from the *start* of the
358 * preregistered buffer that already holds the RPC data in
359 * its middle.
360 * [1] -- the RPC header/data, marshaled by RPC and the NFS protocol.
361 * [2] -- optional padding.
362 * [3] -- if padded, header only in [1] and data here.
363 */
364
365int
366rpcrdma_marshal_req(struct rpc_rqst *rqst)
367{
368 struct rpc_xprt *xprt = rqst->rq_task->tk_xprt;
369 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
370 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
371 char *base;
372 size_t hdrlen, rpclen, padlen;
373 enum rpcrdma_chunktype rtype, wtype;
374 struct rpcrdma_msg *headerp;
375
376 /*
377 * rpclen gets amount of data in first buffer, which is the
378 * pre-registered buffer.
379 */
380 base = rqst->rq_svec[0].iov_base;
381 rpclen = rqst->rq_svec[0].iov_len;
382
383 /* build RDMA header in private area at front */
384 headerp = (struct rpcrdma_msg *) req->rl_base;
385 /* don't htonl XID, it's already done in request */
386 headerp->rm_xid = rqst->rq_xid;
387 headerp->rm_vers = xdr_one;
388 headerp->rm_credit = htonl(r_xprt->rx_buf.rb_max_requests);
389 headerp->rm_type = htonl(RDMA_MSG);
390
391 /*
392 * Chunks needed for results?
393 *
394 * o If the expected result is under the inline threshold, all ops
395 * return as inline (but see later).
396 * o Large non-read ops return as a single reply chunk.
397 * o Large read ops return data as write chunk(s), header as inline.
398 *
399 * Note: the NFS code sending down multiple result segments implies
400 * the op is one of read, readdir[plus], readlink or NFSv4 getacl.
401 */
402
403 /*
404 * This code can handle read chunks, write chunks OR reply
405 * chunks -- only one type. If the request is too big to fit
406 * inline, then we will choose read chunks. If the request is
407 * a READ, then use write chunks to separate the file data
408 * into pages; otherwise use reply chunks.
409 */
410 if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
411 wtype = rpcrdma_noch;
412 else if (rqst->rq_rcv_buf.page_len == 0)
413 wtype = rpcrdma_replych;
414 else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
415 wtype = rpcrdma_writech;
416 else
417 wtype = rpcrdma_replych;
418
419 /*
420 * Chunks needed for arguments?
421 *
422 * o If the total request is under the inline threshold, all ops
423 * are sent as inline.
424 * o Large non-write ops are sent with the entire message as a
425 * single read chunk (protocol 0-position special case).
426 * o Large write ops transmit data as read chunk(s), header as
427 * inline.
428 *
429 * Note: the NFS code sending down multiple argument segments
430 * implies the op is a write.
431 * TBD check NFSv4 setacl
432 */
433 if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
434 rtype = rpcrdma_noch;
435 else if (rqst->rq_snd_buf.page_len == 0)
436 rtype = rpcrdma_areadch;
437 else
438 rtype = rpcrdma_readch;
439
440 /* The following simplification is not true forever */
441 if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
442 wtype = rpcrdma_noch;
443 BUG_ON(rtype != rpcrdma_noch && wtype != rpcrdma_noch);
444
445 if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_BOUNCEBUFFERS &&
446 (rtype != rpcrdma_noch || wtype != rpcrdma_noch)) {
447 /* forced to "pure inline"? */
448 dprintk("RPC: %s: too much data (%d/%d) for inline\n",
449 __func__, rqst->rq_rcv_buf.len, rqst->rq_snd_buf.len);
450 return -1;
451 }
452
453 hdrlen = 28; /*sizeof *headerp;*/
454 padlen = 0;
455
456 /*
457 * Pull up any extra send data into the preregistered buffer.
458 * When padding is in use and applies to the transfer, insert
459 * it and change the message type.
460 */
461 if (rtype == rpcrdma_noch) {
462
463 padlen = rpcrdma_inline_pullup(rqst,
464 RPCRDMA_INLINE_PAD_VALUE(rqst));
465
466 if (padlen) {
467 headerp->rm_type = htonl(RDMA_MSGP);
468 headerp->rm_body.rm_padded.rm_align =
469 htonl(RPCRDMA_INLINE_PAD_VALUE(rqst));
470 headerp->rm_body.rm_padded.rm_thresh =
471 htonl(RPCRDMA_INLINE_PAD_THRESH);
472 headerp->rm_body.rm_padded.rm_pempty[0] = xdr_zero;
473 headerp->rm_body.rm_padded.rm_pempty[1] = xdr_zero;
474 headerp->rm_body.rm_padded.rm_pempty[2] = xdr_zero;
475 hdrlen += 2 * sizeof(u32); /* extra words in padhdr */
476 BUG_ON(wtype != rpcrdma_noch);
477
478 } else {
479 headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
480 headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
481 headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
482 /* new length after pullup */
483 rpclen = rqst->rq_svec[0].iov_len;
484 /*
485 * Currently we try to not actually use read inline.
486 * Reply chunks have the desirable property that
487 * they land, packed, directly in the target buffers
488 * without headers, so they require no fixup. The
489 * additional RDMA Write op sends the same amount
490 * of data, streams on-the-wire and adds no overhead
491 * on receive. Therefore, we request a reply chunk
492 * for non-writes wherever feasible and efficient.
493 */
494 if (wtype == rpcrdma_noch &&
495 r_xprt->rx_ia.ri_memreg_strategy > RPCRDMA_REGISTER)
496 wtype = rpcrdma_replych;
497 }
498 }
499
500 /*
501 * Marshal chunks. This routine will return the header length
502 * consumed by marshaling.
503 */
504 if (rtype != rpcrdma_noch) {
505 hdrlen = rpcrdma_create_chunks(rqst,
506 &rqst->rq_snd_buf, headerp, rtype);
507 wtype = rtype; /* simplify dprintk */
508
509 } else if (wtype != rpcrdma_noch) {
510 hdrlen = rpcrdma_create_chunks(rqst,
511 &rqst->rq_rcv_buf, headerp, wtype);
512 }
513
514 if (hdrlen == 0)
515 return -1;
516
517 dprintk("RPC: %s: %s: hdrlen %zd rpclen %zd padlen %zd"
518 " headerp 0x%p base 0x%p lkey 0x%x\n",
519 __func__, transfertypes[wtype], hdrlen, rpclen, padlen,
520 headerp, base, req->rl_iov.lkey);
521
522 /*
523 * initialize send_iov's - normally only two: rdma chunk header and
524 * single preregistered RPC header buffer, but if padding is present,
525 * then use a preregistered (and zeroed) pad buffer between the RPC
526 * header and any write data. In all non-rdma cases, any following
527 * data has been copied into the RPC header buffer.
528 */
529 req->rl_send_iov[0].addr = req->rl_iov.addr;
530 req->rl_send_iov[0].length = hdrlen;
531 req->rl_send_iov[0].lkey = req->rl_iov.lkey;
532
533 req->rl_send_iov[1].addr = req->rl_iov.addr + (base - req->rl_base);
534 req->rl_send_iov[1].length = rpclen;
535 req->rl_send_iov[1].lkey = req->rl_iov.lkey;
536
537 req->rl_niovs = 2;
538
539 if (padlen) {
540 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
541
542 req->rl_send_iov[2].addr = ep->rep_pad.addr;
543 req->rl_send_iov[2].length = padlen;
544 req->rl_send_iov[2].lkey = ep->rep_pad.lkey;
545
546 req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
547 req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
548 req->rl_send_iov[3].lkey = req->rl_iov.lkey;
549
550 req->rl_niovs = 4;
551 }
552
553 return 0;
554}
555
556/*
557 * Chase down a received write or reply chunklist to get length
558 * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
559 */
560static int
561rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp)
562{
563 unsigned int i, total_len;
564 struct rpcrdma_write_chunk *cur_wchunk;
565
566 i = ntohl(**iptrp); /* get array count */
567 if (i > max)
568 return -1;
569 cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
570 total_len = 0;
571 while (i--) {
572 struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
573 ifdebug(FACILITY) {
574 u64 off;
575 xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
576 dprintk("RPC: %s: chunk %d@0x%llx:0x%x\n",
577 __func__,
578 ntohl(seg->rs_length),
579 (unsigned long long)off,
580 ntohl(seg->rs_handle));
581 }
582 total_len += ntohl(seg->rs_length);
583 ++cur_wchunk;
584 }
585 /* check and adjust for properly terminated write chunk */
586 if (wrchunk) {
587 __be32 *w = (__be32 *) cur_wchunk;
588 if (*w++ != xdr_zero)
589 return -1;
590 cur_wchunk = (struct rpcrdma_write_chunk *) w;
591 }
592 if ((char *) cur_wchunk > rep->rr_base + rep->rr_len)
593 return -1;
594
595 *iptrp = (__be32 *) cur_wchunk;
596 return total_len;
597}
598
599/*
600 * Scatter inline received data back into provided iov's.
601 */
602static void
603rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
604{
605 int i, npages, curlen, olen;
606 char *destp;
607
608 curlen = rqst->rq_rcv_buf.head[0].iov_len;
609 if (curlen > copy_len) { /* write chunk header fixup */
610 curlen = copy_len;
611 rqst->rq_rcv_buf.head[0].iov_len = curlen;
612 }
613
614 dprintk("RPC: %s: srcp 0x%p len %d hdrlen %d\n",
615 __func__, srcp, copy_len, curlen);
616
617 /* Shift pointer for first receive segment only */
618 rqst->rq_rcv_buf.head[0].iov_base = srcp;
619 srcp += curlen;
620 copy_len -= curlen;
621
622 olen = copy_len;
623 i = 0;
624 rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen;
625 if (copy_len && rqst->rq_rcv_buf.page_len) {
626 npages = PAGE_ALIGN(rqst->rq_rcv_buf.page_base +
627 rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT;
628 for (; i < npages; i++) {
629 if (i == 0)
630 curlen = PAGE_SIZE - rqst->rq_rcv_buf.page_base;
631 else
632 curlen = PAGE_SIZE;
633 if (curlen > copy_len)
634 curlen = copy_len;
635 dprintk("RPC: %s: page %d"
636 " srcp 0x%p len %d curlen %d\n",
637 __func__, i, srcp, copy_len, curlen);
638 destp = kmap_atomic(rqst->rq_rcv_buf.pages[i],
639 KM_SKB_SUNRPC_DATA);
640 if (i == 0)
641 memcpy(destp + rqst->rq_rcv_buf.page_base,
642 srcp, curlen);
643 else
644 memcpy(destp, srcp, curlen);
645 flush_dcache_page(rqst->rq_rcv_buf.pages[i]);
646 kunmap_atomic(destp, KM_SKB_SUNRPC_DATA);
647 srcp += curlen;
648 copy_len -= curlen;
649 if (copy_len == 0)
650 break;
651 }
652 rqst->rq_rcv_buf.page_len = olen - copy_len;
653 } else
654 rqst->rq_rcv_buf.page_len = 0;
655
656 if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) {
657 curlen = copy_len;
658 if (curlen > rqst->rq_rcv_buf.tail[0].iov_len)
659 curlen = rqst->rq_rcv_buf.tail[0].iov_len;
660 if (rqst->rq_rcv_buf.tail[0].iov_base != srcp)
661 memmove(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
662 dprintk("RPC: %s: tail srcp 0x%p len %d curlen %d\n",
663 __func__, srcp, copy_len, curlen);
664 rqst->rq_rcv_buf.tail[0].iov_len = curlen;
665 copy_len -= curlen; ++i;
666 } else
667 rqst->rq_rcv_buf.tail[0].iov_len = 0;
668
669 if (pad) {
670 /* implicit padding on terminal chunk */
671 unsigned char *p = rqst->rq_rcv_buf.tail[0].iov_base;
672 while (pad--)
673 p[rqst->rq_rcv_buf.tail[0].iov_len++] = 0;
674 }
675
676 if (copy_len)
677 dprintk("RPC: %s: %d bytes in"
678 " %d extra segments (%d lost)\n",
679 __func__, olen, i, copy_len);
680
681 /* TBD avoid a warning from call_decode() */
682 rqst->rq_private_buf = rqst->rq_rcv_buf;
683}
684
685/*
686 * This function is called when an async event is posted to
687 * the connection which changes the connection state. All it
688 * does at this point is mark the connection up/down, the rpc
689 * timers do the rest.
690 */
691void
692rpcrdma_conn_func(struct rpcrdma_ep *ep)
693{
694 struct rpc_xprt *xprt = ep->rep_xprt;
695
696 spin_lock_bh(&xprt->transport_lock);
697 if (++xprt->connect_cookie == 0) /* maintain a reserved value */
698 ++xprt->connect_cookie;
699 if (ep->rep_connected > 0) {
700 if (!xprt_test_and_set_connected(xprt))
701 xprt_wake_pending_tasks(xprt, 0);
702 } else {
703 if (xprt_test_and_clear_connected(xprt))
704 xprt_wake_pending_tasks(xprt, -ENOTCONN);
705 }
706 spin_unlock_bh(&xprt->transport_lock);
707}
708
709/*
710 * This function is called when memory window unbind which we are waiting
711 * for completes. Just use rr_func (zeroed by upcall) to signal completion.
712 */
713static void
714rpcrdma_unbind_func(struct rpcrdma_rep *rep)
715{
716 wake_up(&rep->rr_unbind);
717}
718
719/*
720 * Called as a tasklet to do req/reply match and complete a request
721 * Errors must result in the RPC task either being awakened, or
722 * allowed to timeout, to discover the errors at that time.
723 */
724void
725rpcrdma_reply_handler(struct rpcrdma_rep *rep)
726{
727 struct rpcrdma_msg *headerp;
728 struct rpcrdma_req *req;
729 struct rpc_rqst *rqst;
730 struct rpc_xprt *xprt = rep->rr_xprt;
731 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
732 __be32 *iptr;
733 int i, rdmalen, status;
734
735 /* Check status. If bad, signal disconnect and return rep to pool */
736 if (rep->rr_len == ~0U) {
737 rpcrdma_recv_buffer_put(rep);
738 if (r_xprt->rx_ep.rep_connected == 1) {
739 r_xprt->rx_ep.rep_connected = -EIO;
740 rpcrdma_conn_func(&r_xprt->rx_ep);
741 }
742 return;
743 }
744 if (rep->rr_len < 28) {
745 dprintk("RPC: %s: short/invalid reply\n", __func__);
746 goto repost;
747 }
748 headerp = (struct rpcrdma_msg *) rep->rr_base;
749 if (headerp->rm_vers != xdr_one) {
750 dprintk("RPC: %s: invalid version %d\n",
751 __func__, ntohl(headerp->rm_vers));
752 goto repost;
753 }
754
755 /* Get XID and try for a match. */
756 spin_lock(&xprt->transport_lock);
757 rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
758 if (rqst == NULL) {
759 spin_unlock(&xprt->transport_lock);
760 dprintk("RPC: %s: reply 0x%p failed "
761 "to match any request xid 0x%08x len %d\n",
762 __func__, rep, headerp->rm_xid, rep->rr_len);
763repost:
764 r_xprt->rx_stats.bad_reply_count++;
765 rep->rr_func = rpcrdma_reply_handler;
766 if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
767 rpcrdma_recv_buffer_put(rep);
768
769 return;
770 }
771
772 /* get request object */
773 req = rpcr_to_rdmar(rqst);
774
775 dprintk("RPC: %s: reply 0x%p completes request 0x%p\n"
776 " RPC request 0x%p xid 0x%08x\n",
777 __func__, rep, req, rqst, headerp->rm_xid);
778
779 BUG_ON(!req || req->rl_reply);
780
781 /* from here on, the reply is no longer an orphan */
782 req->rl_reply = rep;
783
784 /* check for expected message types */
785 /* The order of some of these tests is important. */
786 switch (headerp->rm_type) {
787 case htonl(RDMA_MSG):
788 /* never expect read chunks */
789 /* never expect reply chunks (two ways to check) */
790 /* never expect write chunks without having offered RDMA */
791 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
792 (headerp->rm_body.rm_chunks[1] == xdr_zero &&
793 headerp->rm_body.rm_chunks[2] != xdr_zero) ||
794 (headerp->rm_body.rm_chunks[1] != xdr_zero &&
795 req->rl_nchunks == 0))
796 goto badheader;
797 if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
798 /* count any expected write chunks in read reply */
799 /* start at write chunk array count */
800 iptr = &headerp->rm_body.rm_chunks[2];
801 rdmalen = rpcrdma_count_chunks(rep,
802 req->rl_nchunks, 1, &iptr);
803 /* check for validity, and no reply chunk after */
804 if (rdmalen < 0 || *iptr++ != xdr_zero)
805 goto badheader;
806 rep->rr_len -=
807 ((unsigned char *)iptr - (unsigned char *)headerp);
808 status = rep->rr_len + rdmalen;
809 r_xprt->rx_stats.total_rdma_reply += rdmalen;
810 /* special case - last chunk may omit padding */
811 if (rdmalen &= 3) {
812 rdmalen = 4 - rdmalen;
813 status += rdmalen;
814 }
815 } else {
816 /* else ordinary inline */
817 rdmalen = 0;
818 iptr = (__be32 *)((unsigned char *)headerp + 28);
819 rep->rr_len -= 28; /*sizeof *headerp;*/
820 status = rep->rr_len;
821 }
822 /* Fix up the rpc results for upper layer */
823 rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen);
824 break;
825
826 case htonl(RDMA_NOMSG):
827 /* never expect read or write chunks, always reply chunks */
828 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
829 headerp->rm_body.rm_chunks[1] != xdr_zero ||
830 headerp->rm_body.rm_chunks[2] != xdr_one ||
831 req->rl_nchunks == 0)
832 goto badheader;
833 iptr = (__be32 *)((unsigned char *)headerp + 28);
834 rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr);
835 if (rdmalen < 0)
836 goto badheader;
837 r_xprt->rx_stats.total_rdma_reply += rdmalen;
838 /* Reply chunk buffer already is the reply vector - no fixup. */
839 status = rdmalen;
840 break;
841
842badheader:
843 default:
844 dprintk("%s: invalid rpcrdma reply header (type %d):"
845 " chunks[012] == %d %d %d"
846 " expected chunks <= %d\n",
847 __func__, ntohl(headerp->rm_type),
848 headerp->rm_body.rm_chunks[0],
849 headerp->rm_body.rm_chunks[1],
850 headerp->rm_body.rm_chunks[2],
851 req->rl_nchunks);
852 status = -EIO;
853 r_xprt->rx_stats.bad_reply_count++;
854 break;
855 }
856
857 /* If using mw bind, start the deregister process now. */
858 /* (Note: if mr_free(), cannot perform it here, in tasklet context) */
859 if (req->rl_nchunks) switch (r_xprt->rx_ia.ri_memreg_strategy) {
860 case RPCRDMA_MEMWINDOWS:
861 for (i = 0; req->rl_nchunks-- > 1;)
862 i += rpcrdma_deregister_external(
863 &req->rl_segments[i], r_xprt, NULL);
864 /* Optionally wait (not here) for unbinds to complete */
865 rep->rr_func = rpcrdma_unbind_func;
866 (void) rpcrdma_deregister_external(&req->rl_segments[i],
867 r_xprt, rep);
868 break;
869 case RPCRDMA_MEMWINDOWS_ASYNC:
870 for (i = 0; req->rl_nchunks--;)
871 i += rpcrdma_deregister_external(&req->rl_segments[i],
872 r_xprt, NULL);
873 break;
874 default:
875 break;
876 }
877
878 dprintk("RPC: %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
879 __func__, xprt, rqst, status);
880 xprt_complete_rqst(rqst->rq_task, status);
881 spin_unlock(&xprt->transport_lock);
882}