FRV: Use generic show_interrupts()
[cris-mirror.git] / net / sunrpc / xprtrdma / svc_rdma_recvfrom.c
blobdf67211c4bafa34449d7449cf221e354884bd39d
1 /*
2 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
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:
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
14 * Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
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.
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.
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.
39 * Author: Tom Tucker <tom@opengridcomputing.com>
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>
50 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
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.
57 static void rdma_build_arg_xdr(struct svc_rqst *rqstp,
58 struct svc_rdma_op_ctxt *ctxt,
59 u32 byte_count)
61 struct page *page;
62 u32 bc;
63 int sge_no;
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;
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;
76 /* Compute bytes past head in the SGL */
77 bc = byte_count - rqstp->rq_arg.head[0].iov_len;
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++;
92 rqstp->rq_respages = &rqstp->rq_pages[sge_no];
94 /* We should never run out of SGE because the limit is defined to
95 * support the max allowed RPC data length
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);
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);
108 ctxt->count = bc;
110 /* Set up tail */
111 rqstp->rq_arg.tail[0].iov_base = NULL;
112 rqstp->rq_arg.tail[0].iov_len = 0;
115 /* Encode a read-chunk-list as an array of IB SGE
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.
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
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)
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;
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 = 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;
167 * Don't bump head->count here because the same page
168 * may be used by multiple SGE.
170 head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no];
171 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1];
173 byte_count -= sge_bytes;
174 ch_bytes -= sge_bytes;
175 sge_no++;
177 * If all bytes for this chunk have been mapped to an
178 * SGE, move to the next SGE
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 = 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;
195 * If this SGE consumed all of the page, move to the
196 * next page
198 if ((sge_bytes + page_off) == PAGE_SIZE) {
199 page_no++;
200 page_off = 0;
202 * If there are still bytes left to map, bump
203 * the page count
205 if (byte_count)
206 head->count++;
207 } else
208 page_off += sge_bytes;
210 BUG_ON(byte_count != 0);
211 return sge_no;
214 /* Map a read-chunk-list to an XDR and fast register the page-list.
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
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
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)
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;
244 frmr = svc_rdma_get_frmr(xprt);
245 if (IS_ERR(frmr))
246 return -ENOMEM;
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;
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];
275 head->count += page_no;
277 /* rq_respages points one past arg pages */
278 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
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 rpl_map->sge[ch_no].iov_base = frmr->kva + offset;
285 rpl_map->sge[ch_no].iov_len = ch->rc_target.rs_length;
286 chl_map->ch[ch_no].count = 1;
287 chl_map->ch[ch_no].start = ch_no;
288 offset += ch->rc_target.rs_length;
289 ch++;
292 ret = svc_rdma_fastreg(xprt, frmr);
293 if (ret)
294 goto fatal_err;
296 return ch_no;
298 fatal_err:
299 printk("svcrdma: error fast registering xdr for xprt %p", xprt);
300 svc_rdma_put_frmr(xprt, frmr);
301 return -EIO;
304 static int rdma_set_ctxt_sge(struct svcxprt_rdma *xprt,
305 struct svc_rdma_op_ctxt *ctxt,
306 struct svc_rdma_fastreg_mr *frmr,
307 struct kvec *vec,
308 u64 *sgl_offset,
309 int count)
311 int i;
312 unsigned long off;
314 ctxt->count = count;
315 ctxt->direction = DMA_FROM_DEVICE;
316 for (i = 0; i < count; i++) {
317 ctxt->sge[i].length = 0; /* in case map fails */
318 if (!frmr) {
319 BUG_ON(0 == virt_to_page(vec[i].iov_base));
320 off = (unsigned long)vec[i].iov_base & ~PAGE_MASK;
321 ctxt->sge[i].addr =
322 ib_dma_map_page(xprt->sc_cm_id->device,
323 virt_to_page(vec[i].iov_base),
324 off,
325 vec[i].iov_len,
326 DMA_FROM_DEVICE);
327 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
328 ctxt->sge[i].addr))
329 return -EINVAL;
330 ctxt->sge[i].lkey = xprt->sc_dma_lkey;
331 atomic_inc(&xprt->sc_dma_used);
332 } else {
333 ctxt->sge[i].addr = (unsigned long)vec[i].iov_base;
334 ctxt->sge[i].lkey = frmr->mr->lkey;
336 ctxt->sge[i].length = vec[i].iov_len;
337 *sgl_offset = *sgl_offset + vec[i].iov_len;
339 return 0;
342 static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
344 if ((rdma_node_get_transport(xprt->sc_cm_id->device->node_type) ==
345 RDMA_TRANSPORT_IWARP) &&
346 sge_count > 1)
347 return 1;
348 else
349 return min_t(int, sge_count, xprt->sc_max_sge);
353 * Use RDMA_READ to read data from the advertised client buffer into the
354 * XDR stream starting at rq_arg.head[0].iov_base.
355 * Each chunk in the array
356 * contains the following fields:
357 * discrim - '1', This isn't used for data placement
358 * position - The xdr stream offset (the same for every chunk)
359 * handle - RMR for client memory region
360 * length - data transfer length
361 * offset - 64 bit tagged offset in remote memory region
363 * On our side, we need to read into a pagelist. The first page immediately
364 * follows the RPC header.
366 * This function returns:
367 * 0 - No error and no read-list found.
369 * 1 - Successful read-list processing. The data is not yet in
370 * the pagelist and therefore the RPC request must be deferred. The
371 * I/O completion will enqueue the transport again and
372 * svc_rdma_recvfrom will complete the request.
374 * <0 - Error processing/posting read-list.
376 * NOTE: The ctxt must not be touched after the last WR has been posted
377 * because the I/O completion processing may occur on another
378 * processor and free / modify the context. Ne touche pas!
380 static int rdma_read_xdr(struct svcxprt_rdma *xprt,
381 struct rpcrdma_msg *rmsgp,
382 struct svc_rqst *rqstp,
383 struct svc_rdma_op_ctxt *hdr_ctxt)
385 struct ib_send_wr read_wr;
386 struct ib_send_wr inv_wr;
387 int err = 0;
388 int ch_no;
389 int ch_count;
390 int byte_count;
391 int sge_count;
392 u64 sgl_offset;
393 struct rpcrdma_read_chunk *ch;
394 struct svc_rdma_op_ctxt *ctxt = NULL;
395 struct svc_rdma_req_map *rpl_map;
396 struct svc_rdma_req_map *chl_map;
398 /* If no read list is present, return 0 */
399 ch = svc_rdma_get_read_chunk(rmsgp);
400 if (!ch)
401 return 0;
403 svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count);
404 if (ch_count > RPCSVC_MAXPAGES)
405 return -EINVAL;
407 /* Allocate temporary reply and chunk maps */
408 rpl_map = svc_rdma_get_req_map();
409 chl_map = svc_rdma_get_req_map();
411 if (!xprt->sc_frmr_pg_list_len)
412 sge_count = map_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp,
413 rpl_map, chl_map, ch_count,
414 byte_count);
415 else
416 sge_count = fast_reg_read_chunks(xprt, rqstp, hdr_ctxt, rmsgp,
417 rpl_map, chl_map, ch_count,
418 byte_count);
419 if (sge_count < 0) {
420 err = -EIO;
421 goto out;
424 sgl_offset = 0;
425 ch_no = 0;
427 for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
428 ch->rc_discrim != 0; ch++, ch_no++) {
429 next_sge:
430 ctxt = svc_rdma_get_context(xprt);
431 ctxt->direction = DMA_FROM_DEVICE;
432 ctxt->frmr = hdr_ctxt->frmr;
433 ctxt->read_hdr = NULL;
434 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
435 clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
437 /* Prepare READ WR */
438 memset(&read_wr, 0, sizeof read_wr);
439 read_wr.wr_id = (unsigned long)ctxt;
440 read_wr.opcode = IB_WR_RDMA_READ;
441 ctxt->wr_op = read_wr.opcode;
442 read_wr.send_flags = IB_SEND_SIGNALED;
443 read_wr.wr.rdma.rkey = ch->rc_target.rs_handle;
444 read_wr.wr.rdma.remote_addr =
445 get_unaligned(&(ch->rc_target.rs_offset)) +
446 sgl_offset;
447 read_wr.sg_list = ctxt->sge;
448 read_wr.num_sge =
449 rdma_read_max_sge(xprt, chl_map->ch[ch_no].count);
450 err = rdma_set_ctxt_sge(xprt, ctxt, hdr_ctxt->frmr,
451 &rpl_map->sge[chl_map->ch[ch_no].start],
452 &sgl_offset,
453 read_wr.num_sge);
454 if (err) {
455 svc_rdma_unmap_dma(ctxt);
456 svc_rdma_put_context(ctxt, 0);
457 goto out;
459 if (((ch+1)->rc_discrim == 0) &&
460 (read_wr.num_sge == chl_map->ch[ch_no].count)) {
462 * Mark the last RDMA_READ with a bit to
463 * indicate all RPC data has been fetched from
464 * the client and the RPC needs to be enqueued.
466 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
467 if (hdr_ctxt->frmr) {
468 set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
470 * Invalidate the local MR used to map the data
471 * sink.
473 if (xprt->sc_dev_caps &
474 SVCRDMA_DEVCAP_READ_W_INV) {
475 read_wr.opcode =
476 IB_WR_RDMA_READ_WITH_INV;
477 ctxt->wr_op = read_wr.opcode;
478 read_wr.ex.invalidate_rkey =
479 ctxt->frmr->mr->lkey;
480 } else {
481 /* Prepare INVALIDATE WR */
482 memset(&inv_wr, 0, sizeof inv_wr);
483 inv_wr.opcode = IB_WR_LOCAL_INV;
484 inv_wr.send_flags = IB_SEND_SIGNALED;
485 inv_wr.ex.invalidate_rkey =
486 hdr_ctxt->frmr->mr->lkey;
487 read_wr.next = &inv_wr;
490 ctxt->read_hdr = hdr_ctxt;
492 /* Post the read */
493 err = svc_rdma_send(xprt, &read_wr);
494 if (err) {
495 printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n",
496 err);
497 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
498 svc_rdma_unmap_dma(ctxt);
499 svc_rdma_put_context(ctxt, 0);
500 goto out;
502 atomic_inc(&rdma_stat_read);
504 if (read_wr.num_sge < chl_map->ch[ch_no].count) {
505 chl_map->ch[ch_no].count -= read_wr.num_sge;
506 chl_map->ch[ch_no].start += read_wr.num_sge;
507 goto next_sge;
509 sgl_offset = 0;
510 err = 1;
513 out:
514 svc_rdma_put_req_map(rpl_map);
515 svc_rdma_put_req_map(chl_map);
517 /* Detach arg pages. svc_recv will replenish them */
518 for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++)
519 rqstp->rq_pages[ch_no] = NULL;
522 * Detach res pages. svc_release must see a resused count of
523 * zero or it will attempt to put them.
525 while (rqstp->rq_resused)
526 rqstp->rq_respages[--rqstp->rq_resused] = NULL;
528 return err;
531 static int rdma_read_complete(struct svc_rqst *rqstp,
532 struct svc_rdma_op_ctxt *head)
534 int page_no;
535 int ret;
537 BUG_ON(!head);
539 /* Copy RPC pages */
540 for (page_no = 0; page_no < head->count; page_no++) {
541 put_page(rqstp->rq_pages[page_no]);
542 rqstp->rq_pages[page_no] = head->pages[page_no];
544 /* Point rq_arg.pages past header */
545 rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
546 rqstp->rq_arg.page_len = head->arg.page_len;
547 rqstp->rq_arg.page_base = head->arg.page_base;
549 /* rq_respages starts after the last arg page */
550 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no];
551 rqstp->rq_resused = 0;
553 /* Rebuild rq_arg head and tail. */
554 rqstp->rq_arg.head[0] = head->arg.head[0];
555 rqstp->rq_arg.tail[0] = head->arg.tail[0];
556 rqstp->rq_arg.len = head->arg.len;
557 rqstp->rq_arg.buflen = head->arg.buflen;
559 /* Free the context */
560 svc_rdma_put_context(head, 0);
562 /* XXX: What should this be? */
563 rqstp->rq_prot = IPPROTO_MAX;
564 svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
566 ret = rqstp->rq_arg.head[0].iov_len
567 + rqstp->rq_arg.page_len
568 + rqstp->rq_arg.tail[0].iov_len;
569 dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, "
570 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n",
571 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base,
572 rqstp->rq_arg.head[0].iov_len);
574 return ret;
578 * Set up the rqstp thread context to point to the RQ buffer. If
579 * necessary, pull additional data from the client with an RDMA_READ
580 * request.
582 int svc_rdma_recvfrom(struct svc_rqst *rqstp)
584 struct svc_xprt *xprt = rqstp->rq_xprt;
585 struct svcxprt_rdma *rdma_xprt =
586 container_of(xprt, struct svcxprt_rdma, sc_xprt);
587 struct svc_rdma_op_ctxt *ctxt = NULL;
588 struct rpcrdma_msg *rmsgp;
589 int ret = 0;
590 int len;
592 dprintk("svcrdma: rqstp=%p\n", rqstp);
594 spin_lock_bh(&rdma_xprt->sc_rq_dto_lock);
595 if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
596 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
597 struct svc_rdma_op_ctxt,
598 dto_q);
599 list_del_init(&ctxt->dto_q);
601 if (ctxt) {
602 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
603 return rdma_read_complete(rqstp, ctxt);
606 if (!list_empty(&rdma_xprt->sc_rq_dto_q)) {
607 ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next,
608 struct svc_rdma_op_ctxt,
609 dto_q);
610 list_del_init(&ctxt->dto_q);
611 } else {
612 atomic_inc(&rdma_stat_rq_starve);
613 clear_bit(XPT_DATA, &xprt->xpt_flags);
614 ctxt = NULL;
616 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock);
617 if (!ctxt) {
618 /* This is the EAGAIN path. The svc_recv routine will
619 * return -EAGAIN, the nfsd thread will go to call into
620 * svc_recv again and we shouldn't be on the active
621 * transport list
623 if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
624 goto close_out;
626 BUG_ON(ret);
627 goto out;
629 dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n",
630 ctxt, rdma_xprt, rqstp, ctxt->wc_status);
631 BUG_ON(ctxt->wc_status != IB_WC_SUCCESS);
632 atomic_inc(&rdma_stat_recv);
634 /* Build up the XDR from the receive buffers. */
635 rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len);
637 /* Decode the RDMA header. */
638 len = svc_rdma_xdr_decode_req(&rmsgp, rqstp);
639 rqstp->rq_xprt_hlen = len;
641 /* If the request is invalid, reply with an error */
642 if (len < 0) {
643 if (len == -ENOSYS)
644 svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
645 goto close_out;
648 /* Read read-list data. */
649 ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
650 if (ret > 0) {
651 /* read-list posted, defer until data received from client. */
652 goto defer;
654 if (ret < 0) {
655 /* Post of read-list failed, free context. */
656 svc_rdma_put_context(ctxt, 1);
657 return 0;
660 ret = rqstp->rq_arg.head[0].iov_len
661 + rqstp->rq_arg.page_len
662 + rqstp->rq_arg.tail[0].iov_len;
663 svc_rdma_put_context(ctxt, 0);
664 out:
665 dprintk("svcrdma: ret = %d, rq_arg.len =%d, "
666 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n",
667 ret, rqstp->rq_arg.len,
668 rqstp->rq_arg.head[0].iov_base,
669 rqstp->rq_arg.head[0].iov_len);
670 rqstp->rq_prot = IPPROTO_MAX;
671 svc_xprt_copy_addrs(rqstp, xprt);
672 return ret;
674 close_out:
675 if (ctxt)
676 svc_rdma_put_context(ctxt, 1);
677 dprintk("svcrdma: transport %p is closing\n", xprt);
679 * Set the close bit and enqueue it. svc_recv will see the
680 * close bit and call svc_xprt_delete
682 set_bit(XPT_CLOSE, &xprt->xpt_flags);
683 defer:
684 return 0;