diff options
-rw-r--r-- | net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 586 |
1 files changed, 586 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c new file mode 100644 index 000000000000..ab54a736486e --- /dev/null +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | |||
@@ -0,0 +1,586 @@ | |||
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 | */ | ||
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 | struct chunk_sge { | ||
116 | int start; /* sge no for this chunk */ | ||
117 | int count; /* sge count for this chunk */ | ||
118 | }; | ||
119 | |||
120 | /* Encode a read-chunk-list as an array of IB SGE | ||
121 | * | ||
122 | * Assumptions: | ||
123 | * - chunk[0]->position points to pages[0] at an offset of 0 | ||
124 | * - pages[] is not physically or virtually contigous and consists of | ||
125 | * PAGE_SIZE elements. | ||
126 | * | ||
127 | * Output: | ||
128 | * - sge array pointing into pages[] array. | ||
129 | * - chunk_sge array specifying sge index and count for each | ||
130 | * chunk in the read list | ||
131 | * | ||
132 | */ | ||
133 | static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, | ||
134 | struct svc_rqst *rqstp, | ||
135 | struct svc_rdma_op_ctxt *head, | ||
136 | struct rpcrdma_msg *rmsgp, | ||
137 | struct ib_sge *sge, | ||
138 | struct chunk_sge *ch_sge_ary, | ||
139 | int ch_count, | ||
140 | int byte_count) | ||
141 | { | ||
142 | int sge_no; | ||
143 | int sge_bytes; | ||
144 | int page_off; | ||
145 | int page_no; | ||
146 | int ch_bytes; | ||
147 | int ch_no; | ||
148 | struct rpcrdma_read_chunk *ch; | ||
149 | |||
150 | sge_no = 0; | ||
151 | page_no = 0; | ||
152 | page_off = 0; | ||
153 | ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; | ||
154 | ch_no = 0; | ||
155 | ch_bytes = ch->rc_target.rs_length; | ||
156 | head->arg.head[0] = rqstp->rq_arg.head[0]; | ||
157 | head->arg.tail[0] = rqstp->rq_arg.tail[0]; | ||
158 | head->arg.pages = &head->pages[head->count]; | ||
159 | head->sge[0].length = head->count; /* save count of hdr pages */ | ||
160 | head->arg.page_base = 0; | ||
161 | head->arg.page_len = ch_bytes; | ||
162 | head->arg.len = rqstp->rq_arg.len + ch_bytes; | ||
163 | head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes; | ||
164 | head->count++; | ||
165 | ch_sge_ary[0].start = 0; | ||
166 | while (byte_count) { | ||
167 | sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes); | ||
168 | sge[sge_no].addr = | ||
169 | ib_dma_map_page(xprt->sc_cm_id->device, | ||
170 | rqstp->rq_arg.pages[page_no], | ||
171 | page_off, sge_bytes, | ||
172 | DMA_FROM_DEVICE); | ||
173 | sge[sge_no].length = sge_bytes; | ||
174 | sge[sge_no].lkey = xprt->sc_phys_mr->lkey; | ||
175 | /* | ||
176 | * Don't bump head->count here because the same page | ||
177 | * may be used by multiple SGE. | ||
178 | */ | ||
179 | head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no]; | ||
180 | rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1]; | ||
181 | |||
182 | byte_count -= sge_bytes; | ||
183 | ch_bytes -= sge_bytes; | ||
184 | sge_no++; | ||
185 | /* | ||
186 | * If all bytes for this chunk have been mapped to an | ||
187 | * SGE, move to the next SGE | ||
188 | */ | ||
189 | if (ch_bytes == 0) { | ||
190 | ch_sge_ary[ch_no].count = | ||
191 | sge_no - ch_sge_ary[ch_no].start; | ||
192 | ch_no++; | ||
193 | ch++; | ||
194 | ch_sge_ary[ch_no].start = sge_no; | ||
195 | ch_bytes = ch->rc_target.rs_length; | ||
196 | /* If bytes remaining account for next chunk */ | ||
197 | if (byte_count) { | ||
198 | head->arg.page_len += ch_bytes; | ||
199 | head->arg.len += ch_bytes; | ||
200 | head->arg.buflen += ch_bytes; | ||
201 | } | ||
202 | } | ||
203 | /* | ||
204 | * If this SGE consumed all of the page, move to the | ||
205 | * next page | ||
206 | */ | ||
207 | if ((sge_bytes + page_off) == PAGE_SIZE) { | ||
208 | page_no++; | ||
209 | page_off = 0; | ||
210 | /* | ||
211 | * If there are still bytes left to map, bump | ||
212 | * the page count | ||
213 | */ | ||
214 | if (byte_count) | ||
215 | head->count++; | ||
216 | } else | ||
217 | page_off += sge_bytes; | ||
218 | } | ||
219 | BUG_ON(byte_count != 0); | ||
220 | return sge_no; | ||
221 | } | ||
222 | |||
223 | static void rdma_set_ctxt_sge(struct svc_rdma_op_ctxt *ctxt, | ||
224 | struct ib_sge *sge, | ||
225 | u64 *sgl_offset, | ||
226 | int count) | ||
227 | { | ||
228 | int i; | ||
229 | |||
230 | ctxt->count = count; | ||
231 | for (i = 0; i < count; i++) { | ||
232 | ctxt->sge[i].addr = sge[i].addr; | ||
233 | ctxt->sge[i].length = sge[i].length; | ||
234 | *sgl_offset = *sgl_offset + sge[i].length; | ||
235 | } | ||
236 | } | ||
237 | |||
238 | static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) | ||
239 | { | ||
240 | #ifdef RDMA_TRANSPORT_IWARP | ||
241 | if ((RDMA_TRANSPORT_IWARP == | ||
242 | rdma_node_get_transport(xprt->sc_cm_id-> | ||
243 | device->node_type)) | ||
244 | && sge_count > 1) | ||
245 | return 1; | ||
246 | else | ||
247 | #endif | ||
248 | return min_t(int, sge_count, xprt->sc_max_sge); | ||
249 | } | ||
250 | |||
251 | /* | ||
252 | * Use RDMA_READ to read data from the advertised client buffer into the | ||
253 | * XDR stream starting at rq_arg.head[0].iov_base. | ||
254 | * Each chunk in the array | ||
255 | * contains the following fields: | ||
256 | * discrim - '1', This isn't used for data placement | ||
257 | * position - The xdr stream offset (the same for every chunk) | ||
258 | * handle - RMR for client memory region | ||
259 | * length - data transfer length | ||
260 | * offset - 64 bit tagged offset in remote memory region | ||
261 | * | ||
262 | * On our side, we need to read into a pagelist. The first page immediately | ||
263 | * follows the RPC header. | ||
264 | * | ||
265 | * This function returns 1 to indicate success. The data is not yet in | ||
266 | * the pagelist and therefore the RPC request must be deferred. The | ||
267 | * I/O completion will enqueue the transport again and | ||
268 | * svc_rdma_recvfrom will complete the request. | ||
269 | * | ||
270 | * NOTE: The ctxt must not be touched after the last WR has been posted | ||
271 | * because the I/O completion processing may occur on another | ||
272 | * processor and free / modify the context. Ne touche pas! | ||
273 | */ | ||
274 | static int rdma_read_xdr(struct svcxprt_rdma *xprt, | ||
275 | struct rpcrdma_msg *rmsgp, | ||
276 | struct svc_rqst *rqstp, | ||
277 | struct svc_rdma_op_ctxt *hdr_ctxt) | ||
278 | { | ||
279 | struct ib_send_wr read_wr; | ||
280 | int err = 0; | ||
281 | int ch_no; | ||
282 | struct ib_sge *sge; | ||
283 | int ch_count; | ||
284 | int byte_count; | ||
285 | int sge_count; | ||
286 | u64 sgl_offset; | ||
287 | struct rpcrdma_read_chunk *ch; | ||
288 | struct svc_rdma_op_ctxt *ctxt = NULL; | ||
289 | struct svc_rdma_op_ctxt *head; | ||
290 | struct svc_rdma_op_ctxt *tmp_sge_ctxt; | ||
291 | struct svc_rdma_op_ctxt *tmp_ch_ctxt; | ||
292 | struct chunk_sge *ch_sge_ary; | ||
293 | |||
294 | /* If no read list is present, return 0 */ | ||
295 | ch = svc_rdma_get_read_chunk(rmsgp); | ||
296 | if (!ch) | ||
297 | return 0; | ||
298 | |||
299 | /* Allocate temporary contexts to keep SGE */ | ||
300 | BUG_ON(sizeof(struct ib_sge) < sizeof(struct chunk_sge)); | ||
301 | tmp_sge_ctxt = svc_rdma_get_context(xprt); | ||
302 | sge = tmp_sge_ctxt->sge; | ||
303 | tmp_ch_ctxt = svc_rdma_get_context(xprt); | ||
304 | ch_sge_ary = (struct chunk_sge *)tmp_ch_ctxt->sge; | ||
305 | |||
306 | svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count); | ||
307 | sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp, | ||
308 | sge, ch_sge_ary, | ||
309 | ch_count, byte_count); | ||
310 | head = svc_rdma_get_context(xprt); | ||
311 | sgl_offset = 0; | ||
312 | ch_no = 0; | ||
313 | |||
314 | for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; | ||
315 | ch->rc_discrim != 0; ch++, ch_no++) { | ||
316 | next_sge: | ||
317 | if (!ctxt) | ||
318 | ctxt = head; | ||
319 | else { | ||
320 | ctxt->next = svc_rdma_get_context(xprt); | ||
321 | ctxt = ctxt->next; | ||
322 | } | ||
323 | ctxt->next = NULL; | ||
324 | ctxt->direction = DMA_FROM_DEVICE; | ||
325 | clear_bit(RDMACTXT_F_READ_DONE, &ctxt->flags); | ||
326 | clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); | ||
327 | if ((ch+1)->rc_discrim == 0) { | ||
328 | /* | ||
329 | * Checked in sq_cq_reap to see if we need to | ||
330 | * be enqueued | ||
331 | */ | ||
332 | set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); | ||
333 | ctxt->next = hdr_ctxt; | ||
334 | hdr_ctxt->next = head; | ||
335 | } | ||
336 | |||
337 | /* Prepare READ WR */ | ||
338 | memset(&read_wr, 0, sizeof read_wr); | ||
339 | ctxt->wr_op = IB_WR_RDMA_READ; | ||
340 | read_wr.wr_id = (unsigned long)ctxt; | ||
341 | read_wr.opcode = IB_WR_RDMA_READ; | ||
342 | read_wr.send_flags = IB_SEND_SIGNALED; | ||
343 | read_wr.wr.rdma.rkey = ch->rc_target.rs_handle; | ||
344 | read_wr.wr.rdma.remote_addr = | ||
345 | get_unaligned(&(ch->rc_target.rs_offset)) + | ||
346 | sgl_offset; | ||
347 | read_wr.sg_list = &sge[ch_sge_ary[ch_no].start]; | ||
348 | read_wr.num_sge = | ||
349 | rdma_read_max_sge(xprt, ch_sge_ary[ch_no].count); | ||
350 | rdma_set_ctxt_sge(ctxt, &sge[ch_sge_ary[ch_no].start], | ||
351 | &sgl_offset, | ||
352 | read_wr.num_sge); | ||
353 | |||
354 | /* Post the read */ | ||
355 | err = svc_rdma_send(xprt, &read_wr); | ||
356 | if (err) { | ||
357 | printk(KERN_ERR "svcrdma: Error posting send = %d\n", | ||
358 | err); | ||
359 | /* | ||
360 | * Break the circular list so free knows when | ||
361 | * to stop if the error happened to occur on | ||
362 | * the last read | ||
363 | */ | ||
364 | ctxt->next = NULL; | ||
365 | goto out; | ||
366 | } | ||
367 | atomic_inc(&rdma_stat_read); | ||
368 | |||
369 | if (read_wr.num_sge < ch_sge_ary[ch_no].count) { | ||
370 | ch_sge_ary[ch_no].count -= read_wr.num_sge; | ||
371 | ch_sge_ary[ch_no].start += read_wr.num_sge; | ||
372 | goto next_sge; | ||
373 | } | ||
374 | sgl_offset = 0; | ||
375 | err = 0; | ||
376 | } | ||
377 | |||
378 | out: | ||
379 | svc_rdma_put_context(tmp_sge_ctxt, 0); | ||
380 | svc_rdma_put_context(tmp_ch_ctxt, 0); | ||
381 | |||
382 | /* Detach arg pages. svc_recv will replenish them */ | ||
383 | for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++) | ||
384 | rqstp->rq_pages[ch_no] = NULL; | ||
385 | |||
386 | /* | ||
387 | * Detach res pages. svc_release must see a resused count of | ||
388 | * zero or it will attempt to put them. | ||
389 | */ | ||
390 | while (rqstp->rq_resused) | ||
391 | rqstp->rq_respages[--rqstp->rq_resused] = NULL; | ||
392 | |||
393 | if (err) { | ||
394 | printk(KERN_ERR "svcrdma : RDMA_READ error = %d\n", err); | ||
395 | set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); | ||
396 | /* Free the linked list of read contexts */ | ||
397 | while (head != NULL) { | ||
398 | ctxt = head->next; | ||
399 | svc_rdma_put_context(head, 1); | ||
400 | head = ctxt; | ||
401 | } | ||
402 | return 0; | ||
403 | } | ||
404 | |||
405 | return 1; | ||
406 | } | ||
407 | |||
408 | static int rdma_read_complete(struct svc_rqst *rqstp, | ||
409 | struct svc_rdma_op_ctxt *data) | ||
410 | { | ||
411 | struct svc_rdma_op_ctxt *head = data->next; | ||
412 | int page_no; | ||
413 | int ret; | ||
414 | |||
415 | BUG_ON(!head); | ||
416 | |||
417 | /* Copy RPC pages */ | ||
418 | for (page_no = 0; page_no < head->count; page_no++) { | ||
419 | put_page(rqstp->rq_pages[page_no]); | ||
420 | rqstp->rq_pages[page_no] = head->pages[page_no]; | ||
421 | } | ||
422 | /* Point rq_arg.pages past header */ | ||
423 | rqstp->rq_arg.pages = &rqstp->rq_pages[head->sge[0].length]; | ||
424 | rqstp->rq_arg.page_len = head->arg.page_len; | ||
425 | rqstp->rq_arg.page_base = head->arg.page_base; | ||
426 | |||
427 | /* rq_respages starts after the last arg page */ | ||
428 | rqstp->rq_respages = &rqstp->rq_arg.pages[page_no]; | ||
429 | rqstp->rq_resused = 0; | ||
430 | |||
431 | /* Rebuild rq_arg head and tail. */ | ||
432 | rqstp->rq_arg.head[0] = head->arg.head[0]; | ||
433 | rqstp->rq_arg.tail[0] = head->arg.tail[0]; | ||
434 | rqstp->rq_arg.len = head->arg.len; | ||
435 | rqstp->rq_arg.buflen = head->arg.buflen; | ||
436 | |||
437 | /* XXX: What should this be? */ | ||
438 | rqstp->rq_prot = IPPROTO_MAX; | ||
439 | |||
440 | /* | ||
441 | * Free the contexts we used to build the RDMA_READ. We have | ||
442 | * to be careful here because the context list uses the same | ||
443 | * next pointer used to chain the contexts associated with the | ||
444 | * RDMA_READ | ||
445 | */ | ||
446 | data->next = NULL; /* terminate circular list */ | ||
447 | do { | ||
448 | data = head->next; | ||
449 | svc_rdma_put_context(head, 0); | ||
450 | head = data; | ||
451 | } while (head != NULL); | ||
452 | |||
453 | ret = rqstp->rq_arg.head[0].iov_len | ||
454 | + rqstp->rq_arg.page_len | ||
455 | + rqstp->rq_arg.tail[0].iov_len; | ||
456 | dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, " | ||
457 | "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", | ||
458 | ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, | ||
459 | rqstp->rq_arg.head[0].iov_len); | ||
460 | |||
461 | /* Indicate that we've consumed an RQ credit */ | ||
462 | rqstp->rq_xprt_ctxt = rqstp->rq_xprt; | ||
463 | svc_xprt_received(rqstp->rq_xprt); | ||
464 | return ret; | ||
465 | } | ||
466 | |||
467 | /* | ||
468 | * Set up the rqstp thread context to point to the RQ buffer. If | ||
469 | * necessary, pull additional data from the client with an RDMA_READ | ||
470 | * request. | ||
471 | */ | ||
472 | int svc_rdma_recvfrom(struct svc_rqst *rqstp) | ||
473 | { | ||
474 | struct svc_xprt *xprt = rqstp->rq_xprt; | ||
475 | struct svcxprt_rdma *rdma_xprt = | ||
476 | container_of(xprt, struct svcxprt_rdma, sc_xprt); | ||
477 | struct svc_rdma_op_ctxt *ctxt = NULL; | ||
478 | struct rpcrdma_msg *rmsgp; | ||
479 | int ret = 0; | ||
480 | int len; | ||
481 | |||
482 | dprintk("svcrdma: rqstp=%p\n", rqstp); | ||
483 | |||
484 | /* | ||
485 | * The rq_xprt_ctxt indicates if we've consumed an RQ credit | ||
486 | * or not. It is used in the rdma xpo_release_rqst function to | ||
487 | * determine whether or not to return an RQ WQE to the RQ. | ||
488 | */ | ||
489 | rqstp->rq_xprt_ctxt = NULL; | ||
490 | |||
491 | spin_lock_bh(&rdma_xprt->sc_read_complete_lock); | ||
492 | if (!list_empty(&rdma_xprt->sc_read_complete_q)) { | ||
493 | ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, | ||
494 | struct svc_rdma_op_ctxt, | ||
495 | dto_q); | ||
496 | list_del_init(&ctxt->dto_q); | ||
497 | } | ||
498 | spin_unlock_bh(&rdma_xprt->sc_read_complete_lock); | ||
499 | if (ctxt) | ||
500 | return rdma_read_complete(rqstp, ctxt); | ||
501 | |||
502 | spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); | ||
503 | if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { | ||
504 | ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, | ||
505 | struct svc_rdma_op_ctxt, | ||
506 | dto_q); | ||
507 | list_del_init(&ctxt->dto_q); | ||
508 | } else { | ||
509 | atomic_inc(&rdma_stat_rq_starve); | ||
510 | clear_bit(XPT_DATA, &xprt->xpt_flags); | ||
511 | ctxt = NULL; | ||
512 | } | ||
513 | spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); | ||
514 | if (!ctxt) { | ||
515 | /* This is the EAGAIN path. The svc_recv routine will | ||
516 | * return -EAGAIN, the nfsd thread will go to call into | ||
517 | * svc_recv again and we shouldn't be on the active | ||
518 | * transport list | ||
519 | */ | ||
520 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) | ||
521 | goto close_out; | ||
522 | |||
523 | BUG_ON(ret); | ||
524 | goto out; | ||
525 | } | ||
526 | dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n", | ||
527 | ctxt, rdma_xprt, rqstp, ctxt->wc_status); | ||
528 | BUG_ON(ctxt->wc_status != IB_WC_SUCCESS); | ||
529 | atomic_inc(&rdma_stat_recv); | ||
530 | |||
531 | /* Build up the XDR from the receive buffers. */ | ||
532 | rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len); | ||
533 | |||
534 | /* Decode the RDMA header. */ | ||
535 | len = svc_rdma_xdr_decode_req(&rmsgp, rqstp); | ||
536 | rqstp->rq_xprt_hlen = len; | ||
537 | |||
538 | /* If the request is invalid, reply with an error */ | ||
539 | if (len < 0) { | ||
540 | if (len == -ENOSYS) | ||
541 | (void)svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS); | ||
542 | goto close_out; | ||
543 | } | ||
544 | |||
545 | /* Read read-list data. If we would need to wait, defer | ||
546 | * it. Not that in this case, we don't return the RQ credit | ||
547 | * until after the read completes. | ||
548 | */ | ||
549 | if (rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt)) { | ||
550 | svc_xprt_received(xprt); | ||
551 | return 0; | ||
552 | } | ||
553 | |||
554 | /* Indicate we've consumed an RQ credit */ | ||
555 | rqstp->rq_xprt_ctxt = rqstp->rq_xprt; | ||
556 | |||
557 | ret = rqstp->rq_arg.head[0].iov_len | ||
558 | + rqstp->rq_arg.page_len | ||
559 | + rqstp->rq_arg.tail[0].iov_len; | ||
560 | svc_rdma_put_context(ctxt, 0); | ||
561 | out: | ||
562 | dprintk("svcrdma: ret = %d, rq_arg.len =%d, " | ||
563 | "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", | ||
564 | ret, rqstp->rq_arg.len, | ||
565 | rqstp->rq_arg.head[0].iov_base, | ||
566 | rqstp->rq_arg.head[0].iov_len); | ||
567 | rqstp->rq_prot = IPPROTO_MAX; | ||
568 | svc_xprt_copy_addrs(rqstp, xprt); | ||
569 | svc_xprt_received(xprt); | ||
570 | return ret; | ||
571 | |||
572 | close_out: | ||
573 | if (ctxt) { | ||
574 | svc_rdma_put_context(ctxt, 1); | ||
575 | /* Indicate we've consumed an RQ credit */ | ||
576 | rqstp->rq_xprt_ctxt = rqstp->rq_xprt; | ||
577 | } | ||
578 | dprintk("svcrdma: transport %p is closing\n", xprt); | ||
579 | /* | ||
580 | * Set the close bit and enqueue it. svc_recv will see the | ||
581 | * close bit and call svc_xprt_delete | ||
582 | */ | ||
583 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | ||
584 | svc_xprt_received(xprt); | ||
585 | return 0; | ||
586 | } | ||