1 /*
2 * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
3 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
4 *
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the BSD-type
9 * license below:
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials provided
21 * with the distribution.
22 *
23 * Neither the name of the Network Appliance, Inc. nor the names of
24 * its contributors may be used to endorse or promote products
25 * derived from this software without specific prior written
26 * permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Author: Tom Tucker <tom@opengridcomputing.com>
41 */
42
43 #include <linux/sunrpc/debug.h>
44 #include <linux/sunrpc/rpc_rdma.h>
45 #include <linux/spinlock.h>
46 #include <asm/unaligned.h>
47 #include <rdma/ib_verbs.h>
48 #include <rdma/rdma_cm.h>
49 #include <linux/sunrpc/svc_rdma.h>
50
51 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
52
53 /*
54 * Replace the pages in the rq_argpages array with the pages from the SGE in
55 * the RDMA_RECV completion. The SGL should contain full pages up until the
56 * last one.
57 */
rdma_build_arg_xdr(struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * ctxt,u32 byte_count)58 static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
59 struct svc_rdma_op_ctxt *ctxt,
60 u32 byte_count)
61 {
62 struct rpcrdma_msg *rmsgp;
63 struct page *page;
64 u32 bc;
65 int sge_no;
66
67 /* Swap the page in the SGE with the page in argpages */
68 page = ctxt->pages[0];
69 put_page(rqstp->rq_pages[0]);
70 rqstp->rq_pages[0] = page;
71
72 /* Set up the XDR head */
73 rqstp->rq_arg.head[0].iov_base = page_address(page);
74 rqstp->rq_arg.head[0].iov_len =
75 min_t(size_t, byte_count, ctxt->sge[0].length);
76 rqstp->rq_arg.len = byte_count;
77 rqstp->rq_arg.buflen = byte_count;
78
79 /* Compute bytes past head in the SGL */
80 bc = byte_count - rqstp->rq_arg.head[0].iov_len;
81
82 /* If data remains, store it in the pagelist */
83 rqstp->rq_arg.page_len = bc;
84 rqstp->rq_arg.page_base = 0;
85
86 /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */
87 rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
88 if (be32_to_cpu(rmsgp->rm_type) == RDMA_NOMSG)
89 rqstp->rq_arg.pages = &rqstp->rq_pages[0];
90 else
91 rqstp->rq_arg.pages = &rqstp->rq_pages[1];
92
93 sge_no = 1;
94 while (bc && sge_no < ctxt->count) {
95 page = ctxt->pages[sge_no];
96 put_page(rqstp->rq_pages[sge_no]);
97 rqstp->rq_pages[sge_no] = page;
98 bc -= min_t(u32, bc, ctxt->sge[sge_no].length);
99 rqstp->rq_arg.buflen += ctxt->sge[sge_no].length;
100 sge_no++;
101 }
102 rqstp->rq_respages = &rqstp->rq_pages[sge_no];
103 rqstp->rq_next_page = rqstp->rq_respages + 1;
104
105 /* If not all pages were used from the SGL, free the remaining ones */
106 bc = sge_no;
107 while (sge_no < ctxt->count) {
108 page = ctxt->pages[sge_no++];
109 put_page(page);
110 }
111 ctxt->count = bc;
112
113 /* Set up tail */
114 rqstp->rq_arg.tail[0].iov_base = NULL;
115 rqstp->rq_arg.tail[0].iov_len = 0;
116 }
117
rdma_read_max_sge(struct svcxprt_rdma * xprt,int sge_count)118 static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
119 {
120 if (rdma_node_get_transport(xprt->sc_cm_id->device->node_type) ==
121 RDMA_TRANSPORT_IWARP)
122 return 1;
123 else
124 return min_t(int, sge_count, xprt->sc_max_sge);
125 }
126
127 /* Issue an RDMA_READ using the local lkey to map the data sink */
rdma_read_chunk_lcl(struct svcxprt_rdma * xprt,struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head,int * page_no,u32 * page_offset,u32 rs_handle,u32 rs_length,u64 rs_offset,bool last)128 int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
129 struct svc_rqst *rqstp,
130 struct svc_rdma_op_ctxt *head,
131 int *page_no,
132 u32 *page_offset,
133 u32 rs_handle,
134 u32 rs_length,
135 u64 rs_offset,
136 bool last)
137 {
138 struct ib_send_wr read_wr;
139 int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
140 struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt);
141 int ret, read, pno;
142 u32 pg_off = *page_offset;
143 u32 pg_no = *page_no;
144
145 ctxt->direction = DMA_FROM_DEVICE;
146 ctxt->read_hdr = head;
147 pages_needed =
148 min_t(int, pages_needed, rdma_read_max_sge(xprt, pages_needed));
149 read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset,
150 rs_length);
151
152 for (pno = 0; pno < pages_needed; pno++) {
153 int len = min_t(int, rs_length, PAGE_SIZE - pg_off);
154
155 head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
156 head->arg.page_len += len;
157 head->arg.len += len;
158 if (!pg_off)
159 head->count++;
160 rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1];
161 rqstp->rq_next_page = rqstp->rq_respages + 1;
162 ctxt->sge[pno].addr =
163 ib_dma_map_page(xprt->sc_cm_id->device,
164 head->arg.pages[pg_no], pg_off,
165 PAGE_SIZE - pg_off,
166 DMA_FROM_DEVICE);
167 ret = ib_dma_mapping_error(xprt->sc_cm_id->device,
168 ctxt->sge[pno].addr);
169 if (ret)
170 goto err;
171 atomic_inc(&xprt->sc_dma_used);
172
173 /* The lkey here is either a local dma lkey or a dma_mr lkey */
174 ctxt->sge[pno].lkey = xprt->sc_dma_lkey;
175 ctxt->sge[pno].length = len;
176 ctxt->count++;
177
178 /* adjust offset and wrap to next page if needed */
179 pg_off += len;
180 if (pg_off == PAGE_SIZE) {
181 pg_off = 0;
182 pg_no++;
183 }
184 rs_length -= len;
185 }
186
187 if (last && rs_length == 0)
188 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
189 else
190 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
191
192 memset(&read_wr, 0, sizeof(read_wr));
193 read_wr.wr_id = (unsigned long)ctxt;
194 read_wr.opcode = IB_WR_RDMA_READ;
195 ctxt->wr_op = read_wr.opcode;
196 read_wr.send_flags = IB_SEND_SIGNALED;
197 read_wr.wr.rdma.rkey = rs_handle;
198 read_wr.wr.rdma.remote_addr = rs_offset;
199 read_wr.sg_list = ctxt->sge;
200 read_wr.num_sge = pages_needed;
201
202 ret = svc_rdma_send(xprt, &read_wr);
203 if (ret) {
204 pr_err("svcrdma: Error %d posting RDMA_READ\n", ret);
205 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
206 goto err;
207 }
208
209 /* return current location in page array */
210 *page_no = pg_no;
211 *page_offset = pg_off;
212 ret = read;
213 atomic_inc(&rdma_stat_read);
214 return ret;
215 err:
216 svc_rdma_unmap_dma(ctxt);
217 svc_rdma_put_context(ctxt, 0);
218 return ret;
219 }
220
221 /* Issue an RDMA_READ using an FRMR to map the data sink */
rdma_read_chunk_frmr(struct svcxprt_rdma * xprt,struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head,int * page_no,u32 * page_offset,u32 rs_handle,u32 rs_length,u64 rs_offset,bool last)222 int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt,
223 struct svc_rqst *rqstp,
224 struct svc_rdma_op_ctxt *head,
225 int *page_no,
226 u32 *page_offset,
227 u32 rs_handle,
228 u32 rs_length,
229 u64 rs_offset,
230 bool last)
231 {
232 struct ib_send_wr read_wr;
233 struct ib_send_wr inv_wr;
234 struct ib_send_wr fastreg_wr;
235 u8 key;
236 int pages_needed = PAGE_ALIGN(*page_offset + rs_length) >> PAGE_SHIFT;
237 struct svc_rdma_op_ctxt *ctxt = svc_rdma_get_context(xprt);
238 struct svc_rdma_fastreg_mr *frmr = svc_rdma_get_frmr(xprt);
239 int ret, read, pno;
240 u32 pg_off = *page_offset;
241 u32 pg_no = *page_no;
242
243 if (IS_ERR(frmr))
244 return -ENOMEM;
245
246 ctxt->direction = DMA_FROM_DEVICE;
247 ctxt->frmr = frmr;
248 pages_needed = min_t(int, pages_needed, xprt->sc_frmr_pg_list_len);
249 read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset,
250 rs_length);
251
252 frmr->kva = page_address(rqstp->rq_arg.pages[pg_no]);
253 frmr->direction = DMA_FROM_DEVICE;
254 frmr->access_flags = (IB_ACCESS_LOCAL_WRITE|IB_ACCESS_REMOTE_WRITE);
255 frmr->map_len = pages_needed << PAGE_SHIFT;
256 frmr->page_list_len = pages_needed;
257
258 for (pno = 0; pno < pages_needed; pno++) {
259 int len = min_t(int, rs_length, PAGE_SIZE - pg_off);
260
261 head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
262 head->arg.page_len += len;
263 head->arg.len += len;
264 if (!pg_off)
265 head->count++;
266 rqstp->rq_respages = &rqstp->rq_arg.pages[pg_no+1];
267 rqstp->rq_next_page = rqstp->rq_respages + 1;
268 frmr->page_list->page_list[pno] =
269 ib_dma_map_page(xprt->sc_cm_id->device,
270 head->arg.pages[pg_no], 0,
271 PAGE_SIZE, DMA_FROM_DEVICE);
272 ret = ib_dma_mapping_error(xprt->sc_cm_id->device,
273 frmr->page_list->page_list[pno]);
274 if (ret)
275 goto err;
276 atomic_inc(&xprt->sc_dma_used);
277
278 /* adjust offset and wrap to next page if needed */
279 pg_off += len;
280 if (pg_off == PAGE_SIZE) {
281 pg_off = 0;
282 pg_no++;
283 }
284 rs_length -= len;
285 }
286
287 if (last && rs_length == 0)
288 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
289 else
290 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
291
292 /* Bump the key */
293 key = (u8)(frmr->mr->lkey & 0x000000FF);
294 ib_update_fast_reg_key(frmr->mr, ++key);
295
296 ctxt->sge[0].addr = (unsigned long)frmr->kva + *page_offset;
297 ctxt->sge[0].lkey = frmr->mr->lkey;
298 ctxt->sge[0].length = read;
299 ctxt->count = 1;
300 ctxt->read_hdr = head;
301
302 /* Prepare FASTREG WR */
303 memset(&fastreg_wr, 0, sizeof(fastreg_wr));
304 fastreg_wr.opcode = IB_WR_FAST_REG_MR;
305 fastreg_wr.send_flags = IB_SEND_SIGNALED;
306 fastreg_wr.wr.fast_reg.iova_start = (unsigned long)frmr->kva;
307 fastreg_wr.wr.fast_reg.page_list = frmr->page_list;
308 fastreg_wr.wr.fast_reg.page_list_len = frmr->page_list_len;
309 fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
310 fastreg_wr.wr.fast_reg.length = frmr->map_len;
311 fastreg_wr.wr.fast_reg.access_flags = frmr->access_flags;
312 fastreg_wr.wr.fast_reg.rkey = frmr->mr->lkey;
313 fastreg_wr.next = &read_wr;
314
315 /* Prepare RDMA_READ */
316 memset(&read_wr, 0, sizeof(read_wr));
317 read_wr.send_flags = IB_SEND_SIGNALED;
318 read_wr.wr.rdma.rkey = rs_handle;
319 read_wr.wr.rdma.remote_addr = rs_offset;
320 read_wr.sg_list = ctxt->sge;
321 read_wr.num_sge = 1;
322 if (xprt->sc_dev_caps & SVCRDMA_DEVCAP_READ_W_INV) {
323 read_wr.opcode = IB_WR_RDMA_READ_WITH_INV;
324 read_wr.wr_id = (unsigned long)ctxt;
325 read_wr.ex.invalidate_rkey = ctxt->frmr->mr->lkey;
326 } else {
327 read_wr.opcode = IB_WR_RDMA_READ;
328 read_wr.next = &inv_wr;
329 /* Prepare invalidate */
330 memset(&inv_wr, 0, sizeof(inv_wr));
331 inv_wr.wr_id = (unsigned long)ctxt;
332 inv_wr.opcode = IB_WR_LOCAL_INV;
333 inv_wr.send_flags = IB_SEND_SIGNALED | IB_SEND_FENCE;
334 inv_wr.ex.invalidate_rkey = frmr->mr->lkey;
335 }
336 ctxt->wr_op = read_wr.opcode;
337
338 /* Post the chain */
339 ret = svc_rdma_send(xprt, &fastreg_wr);
340 if (ret) {
341 pr_err("svcrdma: Error %d posting RDMA_READ\n", ret);
342 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
343 goto err;
344 }
345
346 /* return current location in page array */
347 *page_no = pg_no;
348 *page_offset = pg_off;
349 ret = read;
350 atomic_inc(&rdma_stat_read);
351 return ret;
352 err:
353 svc_rdma_unmap_dma(ctxt);
354 svc_rdma_put_context(ctxt, 0);
355 svc_rdma_put_frmr(xprt, frmr);
356 return ret;
357 }
358
359 static unsigned int
rdma_rcl_chunk_count(struct rpcrdma_read_chunk * ch)360 rdma_rcl_chunk_count(struct rpcrdma_read_chunk *ch)
361 {
362 unsigned int count;
363
364 for (count = 0; ch->rc_discrim != xdr_zero; ch++)
365 count++;
366 return count;
367 }
368
369 /* If there was additional inline content, append it to the end of arg.pages.
370 * Tail copy has to be done after the reader function has determined how many
371 * pages are needed for RDMA READ.
372 */
373 static int
rdma_copy_tail(struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head,u32 position,u32 byte_count,u32 page_offset,int page_no)374 rdma_copy_tail(struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head,
375 u32 position, u32 byte_count, u32 page_offset, int page_no)
376 {
377 char *srcp, *destp;
378 int ret;
379
380 ret = 0;
381 srcp = head->arg.head[0].iov_base + position;
382 byte_count = head->arg.head[0].iov_len - position;
383 if (byte_count > PAGE_SIZE) {
384 dprintk("svcrdma: large tail unsupported\n");
385 return 0;
386 }
387
388 /* Fit as much of the tail on the current page as possible */
389 if (page_offset != PAGE_SIZE) {
390 destp = page_address(rqstp->rq_arg.pages[page_no]);
391 destp += page_offset;
392 while (byte_count--) {
393 *destp++ = *srcp++;
394 page_offset++;
395 if (page_offset == PAGE_SIZE && byte_count)
396 goto more;
397 }
398 goto done;
399 }
400
401 more:
402 /* Fit the rest on the next page */
403 page_no++;
404 destp = page_address(rqstp->rq_arg.pages[page_no]);
405 while (byte_count--)
406 *destp++ = *srcp++;
407
408 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1];
409 rqstp->rq_next_page = rqstp->rq_respages + 1;
410
411 done:
412 byte_count = head->arg.head[0].iov_len - position;
413 head->arg.page_len += byte_count;
414 head->arg.len += byte_count;
415 head->arg.buflen += byte_count;
416 return 1;
417 }
418
rdma_read_chunks(struct svcxprt_rdma * xprt,struct rpcrdma_msg * rmsgp,struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head)419 static int rdma_read_chunks(struct svcxprt_rdma *xprt,
420 struct rpcrdma_msg *rmsgp,
421 struct svc_rqst *rqstp,
422 struct svc_rdma_op_ctxt *head)
423 {
424 int page_no, ret;
425 struct rpcrdma_read_chunk *ch;
426 u32 handle, page_offset, byte_count;
427 u32 position;
428 u64 rs_offset;
429 bool last;
430
431 /* If no read list is present, return 0 */
432 ch = svc_rdma_get_read_chunk(rmsgp);
433 if (!ch)
434 return 0;
435
436 if (rdma_rcl_chunk_count(ch) > RPCSVC_MAXPAGES)
437 return -EINVAL;
438
439 /* The request is completed when the RDMA_READs complete. The
440 * head context keeps all the pages that comprise the
441 * request.
442 */
443 head->arg.head[0] = rqstp->rq_arg.head[0];
444 head->arg.tail[0] = rqstp->rq_arg.tail[0];
445 head->hdr_count = head->count;
446 head->arg.page_base = 0;
447 head->arg.page_len = 0;
448 head->arg.len = rqstp->rq_arg.len;
449 head->arg.buflen = rqstp->rq_arg.buflen;
450
451 ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
452 position = be32_to_cpu(ch->rc_position);
453
454 /* RDMA_NOMSG: RDMA READ data should land just after RDMA RECV data */
455 if (position == 0) {
456 head->arg.pages = &head->pages[0];
457 page_offset = head->byte_len;
458 } else {
459 head->arg.pages = &head->pages[head->count];
460 page_offset = 0;
461 }
462
463 ret = 0;
464 page_no = 0;
465 for (; ch->rc_discrim != xdr_zero; ch++) {
466 if (be32_to_cpu(ch->rc_position) != position)
467 goto err;
468
469 handle = be32_to_cpu(ch->rc_target.rs_handle),
470 byte_count = be32_to_cpu(ch->rc_target.rs_length);
471 xdr_decode_hyper((__be32 *)&ch->rc_target.rs_offset,
472 &rs_offset);
473
474 while (byte_count > 0) {
475 last = (ch + 1)->rc_discrim == xdr_zero;
476 ret = xprt->sc_reader(xprt, rqstp, head,
477 &page_no, &page_offset,
478 handle, byte_count,
479 rs_offset, last);
480 if (ret < 0)
481 goto err;
482 byte_count -= ret;
483 rs_offset += ret;
484 head->arg.buflen += ret;
485 }
486 }
487
488 /* Read list may need XDR round-up (see RFC 5666, s. 3.7) */
489 if (page_offset & 3) {
490 u32 pad = 4 - (page_offset & 3);
491
492 head->arg.page_len += pad;
493 head->arg.len += pad;
494 head->arg.buflen += pad;
495 page_offset += pad;
496 }
497
498 ret = 1;
499 if (position && position < head->arg.head[0].iov_len)
500 ret = rdma_copy_tail(rqstp, head, position,
501 byte_count, page_offset, page_no);
502 head->arg.head[0].iov_len = position;
503 head->position = position;
504
505 err:
506 /* Detach arg pages. svc_recv will replenish them */
507 for (page_no = 0;
508 &rqstp->rq_pages[page_no] < rqstp->rq_respages; page_no++)
509 rqstp->rq_pages[page_no] = NULL;
510
511 return ret;
512 }
513
rdma_read_complete(struct svc_rqst * rqstp,struct svc_rdma_op_ctxt * head)514 static int rdma_read_complete(struct svc_rqst *rqstp,
515 struct svc_rdma_op_ctxt *head)
516 {
517 int page_no;
518 int ret;
519
520 /* Copy RPC pages */
521 for (page_no = 0; page_no < head->count; page_no++) {
522 put_page(rqstp->rq_pages[page_no]);
523 rqstp->rq_pages[page_no] = head->pages[page_no];
524 }
525
526 /* Adjustments made for RDMA_NOMSG type requests */
527 if (head->position == 0) {
528 if (head->arg.len <= head->sge[0].length) {
529 head->arg.head[0].iov_len = head->arg.len -
530 head->byte_len;
531 head->arg.page_len = 0;
532 } else {
533 head->arg.head[0].iov_len = head->sge[0].length -
534 head->byte_len;
535 head->arg.page_len = head->arg.len -
536 head->sge[0].length;
537 }
538 }
539
540 /* Point rq_arg.pages past header */
541 rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
542 rqstp->rq_arg.page_len = head->arg.page_len;
543 rqstp->rq_arg.page_base = head->arg.page_base;
544
545 /* rq_respages starts after the last arg page */
546 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
547 rqstp->rq_next_page = rqstp->rq_respages + 1;
548
549 /* Rebuild rq_arg head and tail. */
550 rqstp->rq_arg.head[0] = head->arg.head[0];
551 rqstp->rq_arg.tail[0] = head->arg.tail[0];
552 rqstp->rq_arg.len = head->arg.len;
553 rqstp->rq_arg.buflen = head->arg.buflen;
554
555 /* Free the context */
556 svc_rdma_put_context(head, 0);
557
558 /* XXX: What should this be? */
559 rqstp->rq_prot = IPPROTO_MAX;
560 svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
561
562 ret = rqstp->rq_arg.head[0].iov_len
563 + rqstp->rq_arg.page_len
564 + rqstp->rq_arg.tail[0].iov_len;
565 dprintk("svcrdma: deferred read ret=%d, rq_arg.len=%u, "
566 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zu\n",
567 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base,
568 rqstp->rq_arg.head[0].iov_len);
569
570 return ret;
571 }
572
573 /*
574 * Set up the rqstp thread context to point to the RQ buffer. If
575 * necessary, pull additional data from the client with an RDMA_READ
576 * request.
577 */
svc_rdma_recvfrom(struct svc_rqst * rqstp)578 int svc_rdma_recvfrom(struct svc_rqst *rqstp)
579 {
580 struct svc_xprt *xprt = rqstp->rq_xprt;
581 struct svcxprt_rdma *rdma_xprt =
582 container_of(xprt, struct svcxprt_rdma, sc_xprt);
583 struct svc_rdma_op_ctxt *ctxt = NULL;
584 struct rpcrdma_msg *rmsgp;
585 int ret = 0;
586 int len;
587
588 dprintk("svcrdma: rqstp=%p\n", rqstp);
589
590 spin_lock_bh(&rdma_xprt->sc_rq_dto_lock);
591 if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
592 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
593 struct svc_rdma_op_ctxt,
594 dto_q);
595 list_del_init(&ctxt->dto_q);
596 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
597 return rdma_read_complete(rqstp, ctxt);
598 } else if (!list_empty(&rdma_xprt->sc_rq_dto_q)) {
599 ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next,
600 struct svc_rdma_op_ctxt,
601 dto_q);
602 list_del_init(&ctxt->dto_q);
603 } else {
604 atomic_inc(&rdma_stat_rq_starve);
605 clear_bit(XPT_DATA, &xprt->xpt_flags);
606 ctxt = NULL;
607 }
608 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
609 if (!ctxt) {
610 /* This is the EAGAIN path. The svc_recv routine will
611 * return -EAGAIN, the nfsd thread will go to call into
612 * svc_recv again and we shouldn't be on the active
613 * transport list
614 */
615 if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
616 goto close_out;
617
618 goto out;
619 }
620 dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n",
621 ctxt, rdma_xprt, rqstp, ctxt->wc_status);
622 atomic_inc(&rdma_stat_recv);
623
624 /* Build up the XDR from the receive buffers. */
625 rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len);
626
627 /* Decode the RDMA header. */
628 len = svc_rdma_xdr_decode_req(&rmsgp, rqstp);
629 rqstp->rq_xprt_hlen = len;
630
631 /* If the request is invalid, reply with an error */
632 if (len < 0) {
633 if (len == -ENOSYS)
634 svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
635 goto close_out;
636 }
637
638 /* Read read-list data. */
639 ret = rdma_read_chunks(rdma_xprt, rmsgp, rqstp, ctxt);
640 if (ret > 0) {
641 /* read-list posted, defer until data received from client. */
642 goto defer;
643 } else if (ret < 0) {
644 /* Post of read-list failed, free context. */
645 svc_rdma_put_context(ctxt, 1);
646 return 0;
647 }
648
649 ret = rqstp->rq_arg.head[0].iov_len
650 + rqstp->rq_arg.page_len
651 + rqstp->rq_arg.tail[0].iov_len;
652 svc_rdma_put_context(ctxt, 0);
653 out:
654 dprintk("svcrdma: ret=%d, rq_arg.len=%u, "
655 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len=%zd\n",
656 ret, rqstp->rq_arg.len,
657 rqstp->rq_arg.head[0].iov_base,
658 rqstp->rq_arg.head[0].iov_len);
659 rqstp->rq_prot = IPPROTO_MAX;
660 svc_xprt_copy_addrs(rqstp, xprt);
661 return ret;
662
663 close_out:
664 if (ctxt)
665 svc_rdma_put_context(ctxt, 1);
666 dprintk("svcrdma: transport %p is closing\n", xprt);
667 /*
668 * Set the close bit and enqueue it. svc_recv will see the
669 * close bit and call svc_xprt_delete
670 */
671 set_bit(XPT_CLOSE, &xprt->xpt_flags);
672 defer:
673 return 0;
674 }
675