~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sunrpc/xprtrdma/rpc_rdma.c

Version: ~ [ linux-5.6-rc3 ] ~ [ linux-5.5.7 ] ~ [ linux-5.4.23 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.107 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.172 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.215 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.215 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 56 enum rpcrdma_chunktype {
 57         rpcrdma_noch = 0,
 58         rpcrdma_readch,
 59         rpcrdma_areadch,
 60         rpcrdma_writech,
 61         rpcrdma_replych
 62 };
 63 
 64 #ifdef RPC_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 /*
 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 
 85 static int
 86 rpcrdma_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         int page_base;
 91         struct page **ppages;
 92 
 93         if (pos == 0 && xdrbuf->head[0].iov_len) {
 94                 seg[n].mr_page = NULL;
 95                 seg[n].mr_offset = xdrbuf->head[0].iov_base;
 96                 seg[n].mr_len = xdrbuf->head[0].iov_len;
 97                 ++n;
 98         }
 99 
100         len = xdrbuf->page_len;
101         ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
102         page_base = xdrbuf->page_base & ~PAGE_MASK;
103         p = 0;
104         while (len && n < nsegs) {
105                 seg[n].mr_page = ppages[p];
106                 seg[n].mr_offset = (void *)(unsigned long) page_base;
107                 seg[n].mr_len = min_t(u32, PAGE_SIZE - page_base, len);
108                 BUG_ON(seg[n].mr_len > PAGE_SIZE);
109                 len -= seg[n].mr_len;
110                 ++n;
111                 ++p;
112                 page_base = 0;  /* page offset only applies to first page */
113         }
114 
115         /* Message overflows the seg array */
116         if (len && n == nsegs)
117                 return 0;
118 
119         if (xdrbuf->tail[0].iov_len) {
120                 /* the rpcrdma protocol allows us to omit any trailing
121                  * xdr pad bytes, saving the server an RDMA operation. */
122                 if (xdrbuf->tail[0].iov_len < 4 && xprt_rdma_pad_optimize)
123                         return n;
124                 if (n == nsegs)
125                         /* Tail remains, but we're out of segments */
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 
169 static unsigned int
170 rpcrdma_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         BUG_ON((r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_FRMR)
253                && (nchunks > 3));
254 
255         /*
256          * finish off header. If write, marshal discrim and nchunks.
257          */
258         if (cur_rchunk) {
259                 iptr = (__be32 *) cur_rchunk;
260                 *iptr++ = xdr_zero;     /* finish the read chunk list */
261                 *iptr++ = xdr_zero;     /* encode a NULL write chunk list */
262                 *iptr++ = xdr_zero;     /* encode a NULL reply chunk */
263         } else {
264                 warray->wc_discrim = xdr_one;
265                 warray->wc_nchunks = htonl(nchunks);
266                 iptr = (__be32 *) cur_wchunk;
267                 if (type == rpcrdma_writech) {
268                         *iptr++ = xdr_zero; /* finish the write chunk list */
269                         *iptr++ = xdr_zero; /* encode a NULL reply chunk */
270                 }
271         }
272 
273         /*
274          * Return header size.
275          */
276         return (unsigned char *)iptr - (unsigned char *)headerp;
277 
278 out:
279         for (pos = 0; nchunks--;)
280                 pos += rpcrdma_deregister_external(
281                                 &req->rl_segments[pos], r_xprt, NULL);
282         return 0;
283 }
284 
285 /*
286  * Copy write data inline.
287  * This function is used for "small" requests. Data which is passed
288  * to RPC via iovecs (or page list) is copied directly into the
289  * pre-registered memory buffer for this request. For small amounts
290  * of data, this is efficient. The cutoff value is tunable.
291  */
292 static int
293 rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
294 {
295         int i, npages, curlen;
296         int copy_len;
297         unsigned char *srcp, *destp;
298         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
299         int page_base;
300         struct page **ppages;
301 
302         destp = rqst->rq_svec[0].iov_base;
303         curlen = rqst->rq_svec[0].iov_len;
304         destp += curlen;
305         /*
306          * Do optional padding where it makes sense. Alignment of write
307          * payload can help the server, if our setting is accurate.
308          */
309         pad -= (curlen + 36/*sizeof(struct rpcrdma_msg_padded)*/);
310         if (pad < 0 || rqst->rq_slen - curlen < RPCRDMA_INLINE_PAD_THRESH)
311                 pad = 0;        /* don't pad this request */
312 
313         dprintk("RPC:       %s: pad %d destp 0x%p len %d hdrlen %d\n",
314                 __func__, pad, destp, rqst->rq_slen, curlen);
315 
316         copy_len = rqst->rq_snd_buf.page_len;
317 
318         if (rqst->rq_snd_buf.tail[0].iov_len) {
319                 curlen = rqst->rq_snd_buf.tail[0].iov_len;
320                 if (destp + copy_len != rqst->rq_snd_buf.tail[0].iov_base) {
321                         memmove(destp + copy_len,
322                                 rqst->rq_snd_buf.tail[0].iov_base, curlen);
323                         r_xprt->rx_stats.pullup_copy_count += curlen;
324                 }
325                 dprintk("RPC:       %s: tail destp 0x%p len %d\n",
326                         __func__, destp + copy_len, curlen);
327                 rqst->rq_svec[0].iov_len += curlen;
328         }
329         r_xprt->rx_stats.pullup_copy_count += copy_len;
330 
331         page_base = rqst->rq_snd_buf.page_base;
332         ppages = rqst->rq_snd_buf.pages + (page_base >> PAGE_SHIFT);
333         page_base &= ~PAGE_MASK;
334         npages = PAGE_ALIGN(page_base+copy_len) >> PAGE_SHIFT;
335         for (i = 0; copy_len && i < npages; i++) {
336                 curlen = PAGE_SIZE - page_base;
337                 if (curlen > copy_len)
338                         curlen = copy_len;
339                 dprintk("RPC:       %s: page %d destp 0x%p len %d curlen %d\n",
340                         __func__, i, destp, copy_len, curlen);
341                 srcp = kmap_atomic(ppages[i]);
342                 memcpy(destp, srcp+page_base, curlen);
343                 kunmap_atomic(srcp);
344                 rqst->rq_svec[0].iov_len += curlen;
345                 destp += curlen;
346                 copy_len -= curlen;
347                 page_base = 0;
348         }
349         /* header now contains entire send message */
350         return pad;
351 }
352 
353 /*
354  * Marshal a request: the primary job of this routine is to choose
355  * the transfer modes. See comments below.
356  *
357  * Uses multiple RDMA IOVs for a request:
358  *  [0] -- RPC RDMA header, which uses memory from the *start* of the
359  *         preregistered buffer that already holds the RPC data in
360  *         its middle.
361  *  [1] -- the RPC header/data, marshaled by RPC and the NFS protocol.
362  *  [2] -- optional padding.
363  *  [3] -- if padded, header only in [1] and data here.
364  */
365 
366 int
367 rpcrdma_marshal_req(struct rpc_rqst *rqst)
368 {
369         struct rpc_xprt *xprt = rqst->rq_task->tk_xprt;
370         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
371         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
372         char *base;
373         size_t hdrlen, rpclen, padlen;
374         enum rpcrdma_chunktype rtype, wtype;
375         struct rpcrdma_msg *headerp;
376 
377         /*
378          * rpclen gets amount of data in first buffer, which is the
379          * pre-registered buffer.
380          */
381         base = rqst->rq_svec[0].iov_base;
382         rpclen = rqst->rq_svec[0].iov_len;
383 
384         /* build RDMA header in private area at front */
385         headerp = (struct rpcrdma_msg *) req->rl_base;
386         /* don't htonl XID, it's already done in request */
387         headerp->rm_xid = rqst->rq_xid;
388         headerp->rm_vers = xdr_one;
389         headerp->rm_credit = htonl(r_xprt->rx_buf.rb_max_requests);
390         headerp->rm_type = htonl(RDMA_MSG);
391 
392         /*
393          * Chunks needed for results?
394          *
395          * o If the expected result is under the inline threshold, all ops
396          *   return as inline (but see later).
397          * o Large non-read ops return as a single reply chunk.
398          * o Large read ops return data as write chunk(s), header as inline.
399          *
400          * Note: the NFS code sending down multiple result segments implies
401          * the op is one of read, readdir[plus], readlink or NFSv4 getacl.
402          */
403 
404         /*
405          * This code can handle read chunks, write chunks OR reply
406          * chunks -- only one type. If the request is too big to fit
407          * inline, then we will choose read chunks. If the request is
408          * a READ, then use write chunks to separate the file data
409          * into pages; otherwise use reply chunks.
410          */
411         if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
412                 wtype = rpcrdma_noch;
413         else if (rqst->rq_rcv_buf.page_len == 0)
414                 wtype = rpcrdma_replych;
415         else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
416                 wtype = rpcrdma_writech;
417         else
418                 wtype = rpcrdma_replych;
419 
420         /*
421          * Chunks needed for arguments?
422          *
423          * o If the total request is under the inline threshold, all ops
424          *   are sent as inline.
425          * o Large non-write ops are sent with the entire message as a
426          *   single read chunk (protocol 0-position special case).
427          * o Large write ops transmit data as read chunk(s), header as
428          *   inline.
429          *
430          * Note: the NFS code sending down multiple argument segments
431          * implies the op is a write.
432          * TBD check NFSv4 setacl
433          */
434         if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
435                 rtype = rpcrdma_noch;
436         else if (rqst->rq_snd_buf.page_len == 0)
437                 rtype = rpcrdma_areadch;
438         else
439                 rtype = rpcrdma_readch;
440 
441         /* The following simplification is not true forever */
442         if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
443                 wtype = rpcrdma_noch;
444         BUG_ON(rtype != rpcrdma_noch && wtype != rpcrdma_noch);
445 
446         if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_BOUNCEBUFFERS &&
447             (rtype != rpcrdma_noch || wtype != rpcrdma_noch)) {
448                 /* forced to "pure inline"? */
449                 dprintk("RPC:       %s: too much data (%d/%d) for inline\n",
450                         __func__, rqst->rq_rcv_buf.len, rqst->rq_snd_buf.len);
451                 return -1;
452         }
453 
454         hdrlen = 28; /*sizeof *headerp;*/
455         padlen = 0;
456 
457         /*
458          * Pull up any extra send data into the preregistered buffer.
459          * When padding is in use and applies to the transfer, insert
460          * it and change the message type.
461          */
462         if (rtype == rpcrdma_noch) {
463 
464                 padlen = rpcrdma_inline_pullup(rqst,
465                                                 RPCRDMA_INLINE_PAD_VALUE(rqst));
466 
467                 if (padlen) {
468                         headerp->rm_type = htonl(RDMA_MSGP);
469                         headerp->rm_body.rm_padded.rm_align =
470                                 htonl(RPCRDMA_INLINE_PAD_VALUE(rqst));
471                         headerp->rm_body.rm_padded.rm_thresh =
472                                 htonl(RPCRDMA_INLINE_PAD_THRESH);
473                         headerp->rm_body.rm_padded.rm_pempty[0] = xdr_zero;
474                         headerp->rm_body.rm_padded.rm_pempty[1] = xdr_zero;
475                         headerp->rm_body.rm_padded.rm_pempty[2] = xdr_zero;
476                         hdrlen += 2 * sizeof(u32); /* extra words in padhdr */
477                         BUG_ON(wtype != rpcrdma_noch);
478 
479                 } else {
480                         headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
481                         headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
482                         headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
483                         /* new length after pullup */
484                         rpclen = rqst->rq_svec[0].iov_len;
485                         /*
486                          * Currently we try to not actually use read inline.
487                          * Reply chunks have the desirable property that
488                          * they land, packed, directly in the target buffers
489                          * without headers, so they require no fixup. The
490                          * additional RDMA Write op sends the same amount
491                          * of data, streams on-the-wire and adds no overhead
492                          * on receive. Therefore, we request a reply chunk
493                          * for non-writes wherever feasible and efficient.
494                          */
495                         if (wtype == rpcrdma_noch &&
496                             r_xprt->rx_ia.ri_memreg_strategy > RPCRDMA_REGISTER)
497                                 wtype = rpcrdma_replych;
498                 }
499         }
500 
501         /*
502          * Marshal chunks. This routine will return the header length
503          * consumed by marshaling.
504          */
505         if (rtype != rpcrdma_noch) {
506                 hdrlen = rpcrdma_create_chunks(rqst,
507                                         &rqst->rq_snd_buf, headerp, rtype);
508                 wtype = rtype;  /* simplify dprintk */
509 
510         } else if (wtype != rpcrdma_noch) {
511                 hdrlen = rpcrdma_create_chunks(rqst,
512                                         &rqst->rq_rcv_buf, headerp, wtype);
513         }
514 
515         if (hdrlen == 0)
516                 return -1;
517 
518         dprintk("RPC:       %s: %s: hdrlen %zd rpclen %zd padlen %zd"
519                 " headerp 0x%p base 0x%p lkey 0x%x\n",
520                 __func__, transfertypes[wtype], hdrlen, rpclen, padlen,
521                 headerp, base, req->rl_iov.lkey);
522 
523         /*
524          * initialize send_iov's - normally only two: rdma chunk header and
525          * single preregistered RPC header buffer, but if padding is present,
526          * then use a preregistered (and zeroed) pad buffer between the RPC
527          * header and any write data. In all non-rdma cases, any following
528          * data has been copied into the RPC header buffer.
529          */
530         req->rl_send_iov[0].addr = req->rl_iov.addr;
531         req->rl_send_iov[0].length = hdrlen;
532         req->rl_send_iov[0].lkey = req->rl_iov.lkey;
533 
534         req->rl_send_iov[1].addr = req->rl_iov.addr + (base - req->rl_base);
535         req->rl_send_iov[1].length = rpclen;
536         req->rl_send_iov[1].lkey = req->rl_iov.lkey;
537 
538         req->rl_niovs = 2;
539 
540         if (padlen) {
541                 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
542 
543                 req->rl_send_iov[2].addr = ep->rep_pad.addr;
544                 req->rl_send_iov[2].length = padlen;
545                 req->rl_send_iov[2].lkey = ep->rep_pad.lkey;
546 
547                 req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
548                 req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
549                 req->rl_send_iov[3].lkey = req->rl_iov.lkey;
550 
551                 req->rl_niovs = 4;
552         }
553 
554         return 0;
555 }
556 
557 /*
558  * Chase down a received write or reply chunklist to get length
559  * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
560  */
561 static int
562 rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp)
563 {
564         unsigned int i, total_len;
565         struct rpcrdma_write_chunk *cur_wchunk;
566 
567         i = ntohl(**iptrp);     /* get array count */
568         if (i > max)
569                 return -1;
570         cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
571         total_len = 0;
572         while (i--) {
573                 struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
574                 ifdebug(FACILITY) {
575                         u64 off;
576                         xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
577                         dprintk("RPC:       %s: chunk %d@0x%llx:0x%x\n",
578                                 __func__,
579                                 ntohl(seg->rs_length),
580                                 (unsigned long long)off,
581                                 ntohl(seg->rs_handle));
582                 }
583                 total_len += ntohl(seg->rs_length);
584                 ++cur_wchunk;
585         }
586         /* check and adjust for properly terminated write chunk */
587         if (wrchunk) {
588                 __be32 *w = (__be32 *) cur_wchunk;
589                 if (*w++ != xdr_zero)
590                         return -1;
591                 cur_wchunk = (struct rpcrdma_write_chunk *) w;
592         }
593         if ((char *) cur_wchunk > rep->rr_base + rep->rr_len)
594                 return -1;
595 
596         *iptrp = (__be32 *) cur_wchunk;
597         return total_len;
598 }
599 
600 /*
601  * Scatter inline received data back into provided iov's.
602  */
603 static void
604 rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
605 {
606         int i, npages, curlen, olen;
607         char *destp;
608         struct page **ppages;
609         int page_base;
610 
611         curlen = rqst->rq_rcv_buf.head[0].iov_len;
612         if (curlen > copy_len) {        /* write chunk header fixup */
613                 curlen = copy_len;
614                 rqst->rq_rcv_buf.head[0].iov_len = curlen;
615         }
616 
617         dprintk("RPC:       %s: srcp 0x%p len %d hdrlen %d\n",
618                 __func__, srcp, copy_len, curlen);
619 
620         /* Shift pointer for first receive segment only */
621         rqst->rq_rcv_buf.head[0].iov_base = srcp;
622         srcp += curlen;
623         copy_len -= curlen;
624 
625         olen = copy_len;
626         i = 0;
627         rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen;
628         page_base = rqst->rq_rcv_buf.page_base;
629         ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT);
630         page_base &= ~PAGE_MASK;
631 
632         if (copy_len && rqst->rq_rcv_buf.page_len) {
633                 npages = PAGE_ALIGN(page_base +
634                         rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT;
635                 for (; i < npages; i++) {
636                         curlen = PAGE_SIZE - page_base;
637                         if (curlen > copy_len)
638                                 curlen = copy_len;
639                         dprintk("RPC:       %s: page %d"
640                                 " srcp 0x%p len %d curlen %d\n",
641                                 __func__, i, srcp, copy_len, curlen);
642                         destp = kmap_atomic(ppages[i]);
643                         memcpy(destp + page_base, srcp, curlen);
644                         flush_dcache_page(ppages[i]);
645                         kunmap_atomic(destp);
646                         srcp += curlen;
647                         copy_len -= curlen;
648                         if (copy_len == 0)
649                                 break;
650                         page_base = 0;
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  */
691 void
692 rpcrdma_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  */
713 static void
714 rpcrdma_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  */
724 void
725 rpcrdma_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);
763 repost:
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         if (req->rl_reply) {
775                 spin_unlock(&xprt->transport_lock);
776                 dprintk("RPC:       %s: duplicate reply 0x%p to RPC "
777                         "request 0x%p: xid 0x%08x\n", __func__, rep, req,
778                         headerp->rm_xid);
779                 goto repost;
780         }
781 
782         dprintk("RPC:       %s: reply 0x%p completes request 0x%p\n"
783                 "                   RPC request 0x%p xid 0x%08x\n",
784                         __func__, rep, req, rqst, headerp->rm_xid);
785 
786         /* from here on, the reply is no longer an orphan */
787         req->rl_reply = rep;
788 
789         /* check for expected message types */
790         /* The order of some of these tests is important. */
791         switch (headerp->rm_type) {
792         case htonl(RDMA_MSG):
793                 /* never expect read chunks */
794                 /* never expect reply chunks (two ways to check) */
795                 /* never expect write chunks without having offered RDMA */
796                 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
797                     (headerp->rm_body.rm_chunks[1] == xdr_zero &&
798                      headerp->rm_body.rm_chunks[2] != xdr_zero) ||
799                     (headerp->rm_body.rm_chunks[1] != xdr_zero &&
800                      req->rl_nchunks == 0))
801                         goto badheader;
802                 if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
803                         /* count any expected write chunks in read reply */
804                         /* start at write chunk array count */
805                         iptr = &headerp->rm_body.rm_chunks[2];
806                         rdmalen = rpcrdma_count_chunks(rep,
807                                                 req->rl_nchunks, 1, &iptr);
808                         /* check for validity, and no reply chunk after */
809                         if (rdmalen < 0 || *iptr++ != xdr_zero)
810                                 goto badheader;
811                         rep->rr_len -=
812                             ((unsigned char *)iptr - (unsigned char *)headerp);
813                         status = rep->rr_len + rdmalen;
814                         r_xprt->rx_stats.total_rdma_reply += rdmalen;
815                         /* special case - last chunk may omit padding */
816                         if (rdmalen &= 3) {
817                                 rdmalen = 4 - rdmalen;
818                                 status += rdmalen;
819                         }
820                 } else {
821                         /* else ordinary inline */
822                         rdmalen = 0;
823                         iptr = (__be32 *)((unsigned char *)headerp + 28);
824                         rep->rr_len -= 28; /*sizeof *headerp;*/
825                         status = rep->rr_len;
826                 }
827                 /* Fix up the rpc results for upper layer */
828                 rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, rdmalen);
829                 break;
830 
831         case htonl(RDMA_NOMSG):
832                 /* never expect read or write chunks, always reply chunks */
833                 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
834                     headerp->rm_body.rm_chunks[1] != xdr_zero ||
835                     headerp->rm_body.rm_chunks[2] != xdr_one ||
836                     req->rl_nchunks == 0)
837                         goto badheader;
838                 iptr = (__be32 *)((unsigned char *)headerp + 28);
839                 rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr);
840                 if (rdmalen < 0)
841                         goto badheader;
842                 r_xprt->rx_stats.total_rdma_reply += rdmalen;
843                 /* Reply chunk buffer already is the reply vector - no fixup. */
844                 status = rdmalen;
845                 break;
846 
847 badheader:
848         default:
849                 dprintk("%s: invalid rpcrdma reply header (type %d):"
850                                 " chunks[012] == %d %d %d"
851                                 " expected chunks <= %d\n",
852                                 __func__, ntohl(headerp->rm_type),
853                                 headerp->rm_body.rm_chunks[0],
854                                 headerp->rm_body.rm_chunks[1],
855                                 headerp->rm_body.rm_chunks[2],
856                                 req->rl_nchunks);
857                 status = -EIO;
858                 r_xprt->rx_stats.bad_reply_count++;
859                 break;
860         }
861 
862         /* If using mw bind, start the deregister process now. */
863         /* (Note: if mr_free(), cannot perform it here, in tasklet context) */
864         if (req->rl_nchunks) switch (r_xprt->rx_ia.ri_memreg_strategy) {
865         case RPCRDMA_MEMWINDOWS:
866                 for (i = 0; req->rl_nchunks-- > 1;)
867                         i += rpcrdma_deregister_external(
868                                 &req->rl_segments[i], r_xprt, NULL);
869                 /* Optionally wait (not here) for unbinds to complete */
870                 rep->rr_func = rpcrdma_unbind_func;
871                 (void) rpcrdma_deregister_external(&req->rl_segments[i],
872                                                    r_xprt, rep);
873                 break;
874         case RPCRDMA_MEMWINDOWS_ASYNC:
875                 for (i = 0; req->rl_nchunks--;)
876                         i += rpcrdma_deregister_external(&req->rl_segments[i],
877                                                          r_xprt, NULL);
878                 break;
879         default:
880                 break;
881         }
882 
883         dprintk("RPC:       %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
884                         __func__, xprt, rqst, status);
885         xprt_complete_rqst(rqst->rq_task, status);
886         spin_unlock(&xprt->transport_lock);
887 }
888 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp