1 /*
2 * Copyright (c) 2005-2006 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 * Author: Tom Tucker <tom@opengridcomputing.com>
40 */
41
42 #include <linux/sunrpc/debug.h>
43 #include <linux/sunrpc/rpc_rdma.h>
44 #include <linux/spinlock.h>
45 #include <asm/unaligned.h>
46 #include <rdma/ib_verbs.h>
47 #include <rdma/rdma_cm.h>
48 #include <linux/sunrpc/svc_rdma.h>
49
50 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
51
52 /*
53 * Replace the pages in the rq_argpages array with the pages from the SGE in
54 * the RDMA_RECV completion. The SGL should contain full pages up until the
55 * last one.
56 */
rdma_build_arg_xdr(struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * ctxt,u32 byte_count)57 static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
58 struct svc_rdma_op_ctxt *ctxt,
59 u32 byte_count)
60 {
61 struct page *page;
62 u32 bc;
63 int sge_no;
64
65 /* Swap the page in the SGE with the page in argpages */
66 page = ctxt->pages[0];
67 put_page(rqstp->rq_pages[0]);
68 rqstp->rq_pages[0] = page;
69
70 /* Set up the XDR head */
71 rqstp->rq_arg.head[0].iov_base = page_address(page);
72 rqstp->rq_arg.head[0].iov_len = min(byte_count, ctxt->sge[0].length);
73 rqstp->rq_arg.len = byte_count;
74 rqstp->rq_arg.buflen = byte_count;
75
76 /* Compute bytes past head in the SGL */
77 bc = byte_count - rqstp->rq_arg.head[0].iov_len;
78
79 /* If data remains, store it in the pagelist */
80 rqstp->rq_arg.page_len = bc;
81 rqstp->rq_arg.page_base = 0;
82 rqstp->rq_arg.pages = &rqstp->rq_pages[1];
83 sge_no = 1;
84 while (bc && sge_no < ctxt->count) {
85 page = ctxt->pages[sge_no];
86 put_page(rqstp->rq_pages[sge_no]);
87 rqstp->rq_pages[sge_no] = page;
88 bc -= min(bc, ctxt->sge[sge_no].length);
89 rqstp->rq_arg.buflen += ctxt->sge[sge_no].length;
90 sge_no++;
91 }
92 rqstp->rq_respages = &rqstp->rq_pages[sge_no];
93
94 /* We should never run out of SGE because the limit is defined to
95 * support the max allowed RPC data length
96 */
97 BUG_ON(bc && (sge_no == ctxt->count));
98 BUG_ON((rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len)
99 != byte_count);
100 BUG_ON(rqstp->rq_arg.len != byte_count);
101
102 /* If not all pages were used from the SGL, free the remaining ones */
103 bc = sge_no;
104 while (sge_no < ctxt->count) {
105 page = ctxt->pages[sge_no++];
106 put_page(page);
107 }
108 ctxt->count = bc;
109
110 /* Set up tail */
111 rqstp->rq_arg.tail[0].iov_base = NULL;
112 rqstp->rq_arg.tail[0].iov_len = 0;
113 }
114
115 /* Encode a read-chunk-list as an array of IB SGE
116 *
117 * Assumptions:
118 * - chunk[0]->position points to pages[0] at an offset of 0
119 * - pages[] is not physically or virtually contiguous and consists of
120 * PAGE_SIZE elements.
121 *
122 * Output:
123 * - sge array pointing into pages[] array.
124 * - chunk_sge array specifying sge index and count for each
125 * chunk in the read list
126 *
127 */
map_read_chunks(struct svcxprt_rdma * xprt,struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head,struct rpcrdma_msg * rmsgp,struct svc_rdma_req_map * rpl_map,struct svc_rdma_req_map * chl_map,int ch_count,int byte_count)128 static int map_read_chunks(struct svcxprt_rdma *xprt,
129 struct svc_rqst *rqstp,
130 struct svc_rdma_op_ctxt *head,
131 struct rpcrdma_msg *rmsgp,
132 struct svc_rdma_req_map *rpl_map,
133 struct svc_rdma_req_map *chl_map,
134 int ch_count,
135 int byte_count)
136 {
137 int sge_no;
138 int sge_bytes;
139 int page_off;
140 int page_no;
141 int ch_bytes;
142 int ch_no;
143 struct rpcrdma_read_chunk *ch;
144
145 sge_no = 0;
146 page_no = 0;
147 page_off = 0;
148 ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
149 ch_no = 0;
150 ch_bytes = ntohl(ch->rc_target.rs_length);
151 head->arg.head[0] = rqstp->rq_arg.head[0];
152 head->arg.tail[0] = rqstp->rq_arg.tail[0];
153 head->arg.pages = &head->pages[head->count];
154 head->hdr_count = head->count; /* save count of hdr pages */
155 head->arg.page_base = 0;
156 head->arg.page_len = ch_bytes;
157 head->arg.len = rqstp->rq_arg.len + ch_bytes;
158 head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes;
159 head->count++;
160 chl_map->ch[0].start = 0;
161 while (byte_count) {
162 rpl_map->sge[sge_no].iov_base =
163 page_address(rqstp->rq_arg.pages[page_no]) + page_off;
164 sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes);
165 rpl_map->sge[sge_no].iov_len = sge_bytes;
166 /*
167 * Don't bump head->count here because the same page
168 * may be used by multiple SGE.
169 */
170 head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no];
171 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1];
172
173 byte_count -= sge_bytes;
174 ch_bytes -= sge_bytes;
175 sge_no++;
176 /*
177 * If all bytes for this chunk have been mapped to an
178 * SGE, move to the next SGE
179 */
180 if (ch_bytes == 0) {
181 chl_map->ch[ch_no].count =
182 sge_no - chl_map->ch[ch_no].start;
183 ch_no++;
184 ch++;
185 chl_map->ch[ch_no].start = sge_no;
186 ch_bytes = ntohl(ch->rc_target.rs_length);
187 /* If bytes remaining account for next chunk */
188 if (byte_count) {
189 head->arg.page_len += ch_bytes;
190 head->arg.len += ch_bytes;
191 head->arg.buflen += ch_bytes;
192 }
193 }
194 /*
195 * If this SGE consumed all of the page, move to the
196 * next page
197 */
198 if ((sge_bytes + page_off) == PAGE_SIZE) {
199 page_no++;
200 page_off = 0;
201 /*
202 * If there are still bytes left to map, bump
203 * the page count
204 */
205 if (byte_count)
206 head->count++;
207 } else
208 page_off += sge_bytes;
209 }
210 BUG_ON(byte_count != 0);
211 return sge_no;
212 }
213
214 /* Map a read-chunk-list to an XDR and fast register the page-list.
215 *
216 * Assumptions:
217 * - chunk[0] position points to pages[0] at an offset of 0
218 * - pages[] will be made physically contiguous by creating a one-off memory
219 * region using the fastreg verb.
220 * - byte_count is # of bytes in read-chunk-list
221 * - ch_count is # of chunks in read-chunk-list
222 *
223 * Output:
224 * - sge array pointing into pages[] array.
225 * - chunk_sge array specifying sge index and count for each
226 * chunk in the read list
227 */
fast_reg_read_chunks(struct svcxprt_rdma * xprt,struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head,struct rpcrdma_msg * rmsgp,struct svc_rdma_req_map * rpl_map,struct svc_rdma_req_map * chl_map,int ch_count,int byte_count)228 static int fast_reg_read_chunks(struct svcxprt_rdma *xprt,
229 struct svc_rqst *rqstp,
230 struct svc_rdma_op_ctxt *head,
231 struct rpcrdma_msg *rmsgp,
232 struct svc_rdma_req_map *rpl_map,
233 struct svc_rdma_req_map *chl_map,
234 int ch_count,
235 int byte_count)
236 {
237 int page_no;
238 int ch_no;
239 u32 offset;
240 struct rpcrdma_read_chunk *ch;
241 struct svc_rdma_fastreg_mr *frmr;
242 int ret = 0;
243
244 frmr = svc_rdma_get_frmr(xprt);
245 if (IS_ERR(frmr))
246 return -ENOMEM;
247
248 head->frmr = frmr;
249 head->arg.head[0] = rqstp->rq_arg.head[0];
250 head->arg.tail[0] = rqstp->rq_arg.tail[0];
251 head->arg.pages = &head->pages[head->count];
252 head->hdr_count = head->count; /* save count of hdr pages */
253 head->arg.page_base = 0;
254 head->arg.page_len = byte_count;
255 head->arg.len = rqstp->rq_arg.len + byte_count;
256 head->arg.buflen = rqstp->rq_arg.buflen + byte_count;
257
258 /* Fast register the page list */
259 frmr->kva = page_address(rqstp->rq_arg.pages[0]);
260 frmr->direction = DMA_FROM_DEVICE;
261 frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE);
262 frmr->map_len = byte_count;
263 frmr->page_list_len = PAGE_ALIGN(byte_count) >> PAGE_SHIFT;
264 for (page_no = 0; page_no < frmr->page_list_len; page_no++) {
265 frmr->page_list->page_list[page_no] =
266 ib_dma_map_page(xprt->sc_cm_id->device,
267 rqstp->rq_arg.pages[page_no], 0,
268 PAGE_SIZE, DMA_FROM_DEVICE);
269 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
270 frmr->page_list->page_list[page_no]))
271 goto fatal_err;
272 atomic_inc(&xprt->sc_dma_used);
273 head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no];
274 }
275 head->count += page_no;
276
277 /* rq_respages points one past arg pages */
278 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
279
280 /* Create the reply and chunk maps */
281 offset = 0;
282 ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
283 for (ch_no = 0; ch_no < ch_count; ch_no++) {
284 int len = ntohl(ch->rc_target.rs_length);
285 rpl_map->sge[ch_no].iov_base = frmr->kva + offset;
286 rpl_map->sge[ch_no].iov_len = len;
287 chl_map->ch[ch_no].count = 1;
288 chl_map->ch[ch_no].start = ch_no;
289 offset += len;
290 ch++;
291 }
292
293 ret = svc_rdma_fastreg(xprt, frmr);
294 if (ret)
295 goto fatal_err;
296
297 return ch_no;
298
299 fatal_err:
300 printk("svcrdma: error fast registering xdr for xprt %p", xprt);
301 svc_rdma_put_frmr(xprt, frmr);
302 return -EIO;
303 }
304
rdma_set_ctxt_sge(struct svcxprt_rdma * xprt,struct svc_rdma_op_ctxt * ctxt,struct svc_rdma_fastreg_mr * frmr,struct kvec * vec,u64 * sgl_offset,int count)305 static int rdma_set_ctxt_sge(struct svcxprt_rdma *xprt,
306 struct svc_rdma_op_ctxt *ctxt,
307 struct svc_rdma_fastreg_mr *frmr,
308 struct kvec *vec,
309 u64 *sgl_offset,
310 int count)
311 {
312 int i;
313 unsigned long off;
314
315 ctxt->count = count;
316 ctxt->direction = DMA_FROM_DEVICE;
317 for (i = 0; i < count; i++) {
318 ctxt->sge[i].length = 0; /* in case map fails */
319 if (!frmr) {
320 BUG_ON(!virt_to_page(vec[i].iov_base));
321 off = (unsigned long)vec[i].iov_base & ~PAGE_MASK;
322 ctxt->sge[i].addr =
323 ib_dma_map_page(xprt->sc_cm_id->device,
324 virt_to_page(vec[i].iov_base),
325 off,
326 vec[i].iov_len,
327 DMA_FROM_DEVICE);
328 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
329 ctxt->sge[i].addr))
330 return -EINVAL;
331 ctxt->sge[i].lkey = xprt->sc_dma_lkey;
332 atomic_inc(&xprt->sc_dma_used);
333 } else {
334 ctxt->sge[i].addr = (unsigned long)vec[i].iov_base;
335 ctxt->sge[i].lkey = frmr->mr->lkey;
336 }
337 ctxt->sge[i].length = vec[i].iov_len;
338 *sgl_offset = *sgl_offset + vec[i].iov_len;
339 }
340 return 0;
341 }
342
rdma_read_max_sge(struct svcxprt_rdma * xprt,int sge_count)343 static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
344 {
345 if ((rdma_node_get_transport(xprt->sc_cm_id->device->node_type) ==
346 RDMA_TRANSPORT_IWARP) &&
347 sge_count > 1)
348 return 1;
349 else
350 return min_t(int, sge_count, xprt->sc_max_sge);
351 }
352
353 /*
354 * Use RDMA_READ to read data from the advertised client buffer into the
355 * XDR stream starting at rq_arg.head[0].iov_base.
356 * Each chunk in the array
357 * contains the following fields:
358 * discrim - '1', This isn't used for data placement
359 * position - The xdr stream offset (the same for every chunk)
360 * handle - RMR for client memory region
361 * length - data transfer length
362 * offset - 64 bit tagged offset in remote memory region
363 *
364 * On our side, we need to read into a pagelist. The first page immediately
365 * follows the RPC header.
366 *
367 * This function returns:
368 * 0 - No error and no read-list found.
369 *
370 * 1 - Successful read-list processing. The data is not yet in
371 * the pagelist and therefore the RPC request must be deferred. The
372 * I/O completion will enqueue the transport again and
373 * svc_rdma_recvfrom will complete the request.
374 *
375 * <0 - Error processing/posting read-list.
376 *
377 * NOTE: The ctxt must not be touched after the last WR has been posted
378 * because the I/O completion processing may occur on another
379 * processor and free / modify the context. Ne touche pas!
380 */
rdma_read_xdr(struct svcxprt_rdma * xprt,struct rpcrdma_msg * rmsgp,struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * hdr_ctxt)381 static int rdma_read_xdr(struct svcxprt_rdma *xprt,
382 struct rpcrdma_msg *rmsgp,
383 struct svc_rqst *rqstp,
384 struct svc_rdma_op_ctxt *hdr_ctxt)
385 {
386 struct ib_send_wr read_wr;
387 struct ib_send_wr inv_wr;
388 int err = 0;
389 int ch_no;
390 int ch_count;
391 int byte_count;
392 int sge_count;
393 u64 sgl_offset;
394 struct rpcrdma_read_chunk *ch;
395 struct svc_rdma_op_ctxt *ctxt = NULL;
396 struct svc_rdma_req_map *rpl_map;
397 struct svc_rdma_req_map *chl_map;
398
399 /* If no read list is present, return 0 */
400 ch = svc_rdma_get_read_chunk(rmsgp);
401 if (!ch)
402 return 0;
403
404 svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count);
405 if (ch_count > RPCSVC_MAXPAGES)
406 return -EINVAL;
407
408 /* Allocate temporary reply and chunk maps */
409 rpl_map = svc_rdma_get_req_map();
410 chl_map = svc_rdma_get_req_map();
411
412 if (!xprt->sc_frmr_pg_list_len)
413 sge_count = map_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp,
414 rpl_map, chl_map, ch_count,
415 byte_count);
416 else
417 sge_count = fast_reg_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp,
418 rpl_map, chl_map, ch_count,
419 byte_count);
420 if (sge_count < 0) {
421 err = -EIO;
422 goto out;
423 }
424
425 sgl_offset = 0;
426 ch_no = 0;
427
428 for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
429 ch->rc_discrim != 0; ch++, ch_no++) {
430 u64 rs_offset;
431 next_sge:
432 ctxt = svc_rdma_get_context(xprt);
433 ctxt->direction = DMA_FROM_DEVICE;
434 ctxt->frmr = hdr_ctxt->frmr;
435 ctxt->read_hdr = NULL;
436 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
437 clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
438
439 /* Prepare READ WR */
440 memset(&read_wr, 0, sizeof read_wr);
441 read_wr.wr_id = (unsigned long)ctxt;
442 read_wr.opcode = IB_WR_RDMA_READ;
443 ctxt->wr_op = read_wr.opcode;
444 read_wr.send_flags = IB_SEND_SIGNALED;
445 read_wr.wr.rdma.rkey = ntohl(ch->rc_target.rs_handle);
446 xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset,
447 &rs_offset);
448 read_wr.wr.rdma.remote_addr = rs_offset + sgl_offset;
449 read_wr.sg_list = ctxt->sge;
450 read_wr.num_sge =
451 rdma_read_max_sge(xprt, chl_map->ch[ch_no].count);
452 err = rdma_set_ctxt_sge(xprt, ctxt, hdr_ctxt->frmr,
453 &rpl_map->sge[chl_map->ch[ch_no].start],
454 &sgl_offset,
455 read_wr.num_sge);
456 if (err) {
457 svc_rdma_unmap_dma(ctxt);
458 svc_rdma_put_context(ctxt, 0);
459 goto out;
460 }
461 if (((ch+1)->rc_discrim == 0) &&
462 (read_wr.num_sge == chl_map->ch[ch_no].count)) {
463 /*
464 * Mark the last RDMA_READ with a bit to
465 * indicate all RPC data has been fetched from
466 * the client and the RPC needs to be enqueued.
467 */
468 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
469 if (hdr_ctxt->frmr) {
470 set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
471 /*
472 * Invalidate the local MR used to map the data
473 * sink.
474 */
475 if (xprt->sc_dev_caps &
476 SVCRDMA_DEVCAP_READ_W_INV) {
477 read_wr.opcode =
478 IB_WR_RDMA_READ_WITH_INV;
479 ctxt->wr_op = read_wr.opcode;
480 read_wr.ex.invalidate_rkey =
481 ctxt->frmr->mr->lkey;
482 } else {
483 /* Prepare INVALIDATE WR */
484 memset(&inv_wr, 0, sizeof inv_wr);
485 inv_wr.opcode = IB_WR_LOCAL_INV;
486 inv_wr.send_flags = IB_SEND_SIGNALED;
487 inv_wr.ex.invalidate_rkey =
488 hdr_ctxt->frmr->mr->lkey;
489 read_wr.next = &inv_wr;
490 }
491 }
492 ctxt->read_hdr = hdr_ctxt;
493 }
494 /* Post the read */
495 err = svc_rdma_send(xprt, &read_wr);
496 if (err) {
497 printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n",
498 err);
499 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
500 svc_rdma_unmap_dma(ctxt);
501 svc_rdma_put_context(ctxt, 0);
502 goto out;
503 }
504 atomic_inc(&rdma_stat_read);
505
506 if (read_wr.num_sge < chl_map->ch[ch_no].count) {
507 chl_map->ch[ch_no].count -= read_wr.num_sge;
508 chl_map->ch[ch_no].start += read_wr.num_sge;
509 goto next_sge;
510 }
511 sgl_offset = 0;
512 err = 1;
513 }
514
515 out:
516 svc_rdma_put_req_map(rpl_map);
517 svc_rdma_put_req_map(chl_map);
518
519 /* Detach arg pages. svc_recv will replenish them */
520 for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++)
521 rqstp->rq_pages[ch_no] = NULL;
522
523 /*
524 * Detach res pages. svc_release must see a resused count of
525 * zero or it will attempt to put them.
526 */
527 while (rqstp->rq_resused)
528 rqstp->rq_respages[--rqstp->rq_resused] = NULL;
529
530 return err;
531 }
532
rdma_read_complete(struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head)533 static int rdma_read_complete(struct svc_rqst *rqstp,
534 struct svc_rdma_op_ctxt *head)
535 {
536 int page_no;
537 int ret;
538
539 BUG_ON(!head);
540
541 /* Copy RPC pages */
542 for (page_no = 0; page_no < head->count; page_no++) {
543 put_page(rqstp->rq_pages[page_no]);
544 rqstp->rq_pages[page_no] = head->pages[page_no];
545 }
546 /* Point rq_arg.pages past header */
547 rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
548 rqstp->rq_arg.page_len = head->arg.page_len;
549 rqstp->rq_arg.page_base = head->arg.page_base;
550
551 /* rq_respages starts after the last arg page */
552 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
553 rqstp->rq_resused = 0;
554
555 /* Rebuild rq_arg head and tail. */
556 rqstp->rq_arg.head[0] = head->arg.head[0];
557 rqstp->rq_arg.tail[0] = head->arg.tail[0];
558 rqstp->rq_arg.len = head->arg.len;
559 rqstp->rq_arg.buflen = head->arg.buflen;
560
561 /* Free the context */
562 svc_rdma_put_context(head, 0);
563
564 /* XXX: What should this be? */
565 rqstp->rq_prot = IPPROTO_MAX;
566 svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
567
568 ret = rqstp->rq_arg.head[0].iov_len
569 + rqstp->rq_arg.page_len
570 + rqstp->rq_arg.tail[0].iov_len;
571 dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, "
572 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n",
573 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base,
574 rqstp->rq_arg.head[0].iov_len);
575
576 return ret;
577 }
578
579 /*
580 * Set up the rqstp thread context to point to the RQ buffer. If
581 * necessary, pull additional data from the client with an RDMA_READ
582 * request.
583 */
svc_rdma_recvfrom(struct svc_rqst * rqstp)584 int svc_rdma_recvfrom(struct svc_rqst *rqstp)
585 {
586 struct svc_xprt *xprt = rqstp->rq_xprt;
587 struct svcxprt_rdma *rdma_xprt =
588 container_of(xprt, struct svcxprt_rdma, sc_xprt);
589 struct svc_rdma_op_ctxt *ctxt = NULL;
590 struct rpcrdma_msg *rmsgp;
591 int ret = 0;
592 int len;
593
594 dprintk("svcrdma: rqstp=%p\n", rqstp);
595
596 spin_lock_bh(&rdma_xprt->sc_rq_dto_lock);
597 if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
598 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
599 struct svc_rdma_op_ctxt,
600 dto_q);
601 list_del_init(&ctxt->dto_q);
602 }
603 if (ctxt) {
604 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
605 return rdma_read_complete(rqstp, ctxt);
606 }
607
608 if (!list_empty(&rdma_xprt->sc_rq_dto_q)) {
609 ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next,
610 struct svc_rdma_op_ctxt,
611 dto_q);
612 list_del_init(&ctxt->dto_q);
613 } else {
614 atomic_inc(&rdma_stat_rq_starve);
615 clear_bit(XPT_DATA, &xprt->xpt_flags);
616 ctxt = NULL;
617 }
618 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
619 if (!ctxt) {
620 /* This is the EAGAIN path. The svc_recv routine will
621 * return -EAGAIN, the nfsd thread will go to call into
622 * svc_recv again and we shouldn't be on the active
623 * transport list
624 */
625 if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
626 goto close_out;
627
628 BUG_ON(ret);
629 goto out;
630 }
631 dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n",
632 ctxt, rdma_xprt, rqstp, ctxt->wc_status);
633 BUG_ON(ctxt->wc_status != IB_WC_SUCCESS);
634 atomic_inc(&rdma_stat_recv);
635
636 /* Build up the XDR from the receive buffers. */
637 rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len);
638
639 /* Decode the RDMA header. */
640 len = svc_rdma_xdr_decode_req(&rmsgp, rqstp);
641 rqstp->rq_xprt_hlen = len;
642
643 /* If the request is invalid, reply with an error */
644 if (len < 0) {
645 if (len == -ENOSYS)
646 svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
647 goto close_out;
648 }
649
650 /* Read read-list data. */
651 ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
652 if (ret > 0) {
653 /* read-list posted, defer until data received from client. */
654 goto defer;
655 }
656 if (ret < 0) {
657 /* Post of read-list failed, free context. */
658 svc_rdma_put_context(ctxt, 1);
659 return 0;
660 }
661
662 ret = rqstp->rq_arg.head[0].iov_len
663 + rqstp->rq_arg.page_len
664 + rqstp->rq_arg.tail[0].iov_len;
665 svc_rdma_put_context(ctxt, 0);
666 out:
667 dprintk("svcrdma: ret = %d, rq_arg.len =%d, "
668 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n",
669 ret, rqstp->rq_arg.len,
670 rqstp->rq_arg.head[0].iov_base,
671 rqstp->rq_arg.head[0].iov_len);
672 rqstp->rq_prot = IPPROTO_MAX;
673 svc_xprt_copy_addrs(rqstp, xprt);
674 return ret;
675
676 close_out:
677 if (ctxt)
678 svc_rdma_put_context(ctxt, 1);
679 dprintk("svcrdma: transport %p is closing\n", xprt);
680 /*
681 * Set the close bit and enqueue it. svc_recv will see the
682 * close bit and call svc_xprt_delete
683 */
684 set_bit(XPT_CLOSE, &xprt->xpt_flags);
685 defer:
686 return 0;
687 }
688