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 * transport.c
42 *
43 * This file contains the top-level implementation of an RPC RDMA
44 * transport.
45 *
46 * Naming convention: functions beginning with xprt_ are part of the
47 * transport switch. All others are RPC RDMA internal.
48 */
49
50 #include <linux/module.h>
51 #include <linux/slab.h>
52 #include <linux/seq_file.h>
53 #include <linux/sunrpc/addr.h>
54
55 #include "xprt_rdma.h"
56
57 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
58 # define RPCDBG_FACILITY RPCDBG_TRANS
59 #endif
60
61 /*
62 * tunables
63 */
64
65 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
66 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
67 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
68 static unsigned int xprt_rdma_inline_write_padding;
69 unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
70 int xprt_rdma_pad_optimize;
71
72 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
73
74 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
75 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
76 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
77 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
78 static unsigned int zero;
79 static unsigned int max_padding = PAGE_SIZE;
80 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
81 static unsigned int max_memreg = RPCRDMA_LAST - 1;
82
83 static struct ctl_table_header *sunrpc_table_header;
84
85 static struct ctl_table xr_tunables_table[] = {
86 {
87 .procname = "rdma_slot_table_entries",
88 .data = &xprt_rdma_slot_table_entries,
89 .maxlen = sizeof(unsigned int),
90 .mode = 0644,
91 .proc_handler = proc_dointvec_minmax,
92 .extra1 = &min_slot_table_size,
93 .extra2 = &max_slot_table_size
94 },
95 {
96 .procname = "rdma_max_inline_read",
97 .data = &xprt_rdma_max_inline_read,
98 .maxlen = sizeof(unsigned int),
99 .mode = 0644,
100 .proc_handler = proc_dointvec_minmax,
101 .extra1 = &min_inline_size,
102 .extra2 = &max_inline_size,
103 },
104 {
105 .procname = "rdma_max_inline_write",
106 .data = &xprt_rdma_max_inline_write,
107 .maxlen = sizeof(unsigned int),
108 .mode = 0644,
109 .proc_handler = proc_dointvec_minmax,
110 .extra1 = &min_inline_size,
111 .extra2 = &max_inline_size,
112 },
113 {
114 .procname = "rdma_inline_write_padding",
115 .data = &xprt_rdma_inline_write_padding,
116 .maxlen = sizeof(unsigned int),
117 .mode = 0644,
118 .proc_handler = proc_dointvec_minmax,
119 .extra1 = &zero,
120 .extra2 = &max_padding,
121 },
122 {
123 .procname = "rdma_memreg_strategy",
124 .data = &xprt_rdma_memreg_strategy,
125 .maxlen = sizeof(unsigned int),
126 .mode = 0644,
127 .proc_handler = proc_dointvec_minmax,
128 .extra1 = &min_memreg,
129 .extra2 = &max_memreg,
130 },
131 {
132 .procname = "rdma_pad_optimize",
133 .data = &xprt_rdma_pad_optimize,
134 .maxlen = sizeof(unsigned int),
135 .mode = 0644,
136 .proc_handler = proc_dointvec,
137 },
138 { },
139 };
140
141 static struct ctl_table sunrpc_table[] = {
142 {
143 .procname = "sunrpc",
144 .mode = 0555,
145 .child = xr_tunables_table
146 },
147 { },
148 };
149
150 #endif
151
152 static const struct rpc_xprt_ops xprt_rdma_procs;
153
154 static void
xprt_rdma_format_addresses4(struct rpc_xprt * xprt,struct sockaddr * sap)155 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
156 {
157 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
158 char buf[20];
159
160 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
161 xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
162
163 xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
164 }
165
166 static void
xprt_rdma_format_addresses6(struct rpc_xprt * xprt,struct sockaddr * sap)167 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
168 {
169 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
170 char buf[40];
171
172 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
173 xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
174
175 xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
176 }
177
178 void
xprt_rdma_format_addresses(struct rpc_xprt * xprt,struct sockaddr * sap)179 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
180 {
181 char buf[128];
182
183 switch (sap->sa_family) {
184 case AF_INET:
185 xprt_rdma_format_addresses4(xprt, sap);
186 break;
187 case AF_INET6:
188 xprt_rdma_format_addresses6(xprt, sap);
189 break;
190 default:
191 pr_err("rpcrdma: Unrecognized address family\n");
192 return;
193 }
194
195 (void)rpc_ntop(sap, buf, sizeof(buf));
196 xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
197
198 snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
199 xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
200
201 snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
202 xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
203
204 xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
205 }
206
207 void
xprt_rdma_free_addresses(struct rpc_xprt * xprt)208 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
209 {
210 unsigned int i;
211
212 for (i = 0; i < RPC_DISPLAY_MAX; i++)
213 switch (i) {
214 case RPC_DISPLAY_PROTO:
215 case RPC_DISPLAY_NETID:
216 continue;
217 default:
218 kfree(xprt->address_strings[i]);
219 }
220 }
221
222 void
rpcrdma_conn_func(struct rpcrdma_ep * ep)223 rpcrdma_conn_func(struct rpcrdma_ep *ep)
224 {
225 schedule_delayed_work(&ep->rep_connect_worker, 0);
226 }
227
228 void
rpcrdma_connect_worker(struct work_struct * work)229 rpcrdma_connect_worker(struct work_struct *work)
230 {
231 struct rpcrdma_ep *ep =
232 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
233 struct rpcrdma_xprt *r_xprt =
234 container_of(ep, struct rpcrdma_xprt, rx_ep);
235 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
236
237 spin_lock_bh(&xprt->transport_lock);
238 if (++xprt->connect_cookie == 0) /* maintain a reserved value */
239 ++xprt->connect_cookie;
240 if (ep->rep_connected > 0) {
241 if (!xprt_test_and_set_connected(xprt)) {
242 xprt->stat.connect_count++;
243 xprt->stat.connect_time += (long)jiffies -
244 xprt->stat.connect_start;
245 xprt_wake_pending_tasks(xprt, 0);
246 }
247 } else {
248 if (xprt_test_and_clear_connected(xprt))
249 xprt_wake_pending_tasks(xprt, -ENOTCONN);
250 }
251 spin_unlock_bh(&xprt->transport_lock);
252 }
253
254 static void
xprt_rdma_connect_worker(struct work_struct * work)255 xprt_rdma_connect_worker(struct work_struct *work)
256 {
257 struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
258 rx_connect_worker.work);
259 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
260 int rc = 0;
261
262 xprt_clear_connected(xprt);
263
264 dprintk("RPC: %s: %sconnect\n", __func__,
265 r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
266 rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
267 if (rc)
268 xprt_wake_pending_tasks(xprt, rc);
269
270 dprintk("RPC: %s: exit\n", __func__);
271 xprt_clear_connecting(xprt);
272 }
273
274 static void
xprt_rdma_inject_disconnect(struct rpc_xprt * xprt)275 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
276 {
277 struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
278 rx_xprt);
279
280 pr_info("rpcrdma: injecting transport disconnect on xprt=%p\n", xprt);
281 rdma_disconnect(r_xprt->rx_ia.ri_id);
282 }
283
284 /*
285 * xprt_rdma_destroy
286 *
287 * Destroy the xprt.
288 * Free all memory associated with the object, including its own.
289 * NOTE: none of the *destroy methods free memory for their top-level
290 * objects, even though they may have allocated it (they do free
291 * private memory). It's up to the caller to handle it. In this
292 * case (RDMA transport), all structure memory is inlined with the
293 * struct rpcrdma_xprt.
294 */
295 static void
xprt_rdma_destroy(struct rpc_xprt * xprt)296 xprt_rdma_destroy(struct rpc_xprt *xprt)
297 {
298 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
299
300 dprintk("RPC: %s: called\n", __func__);
301
302 cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
303
304 xprt_clear_connected(xprt);
305
306 rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
307 rpcrdma_buffer_destroy(&r_xprt->rx_buf);
308 rpcrdma_ia_close(&r_xprt->rx_ia);
309
310 xprt_rdma_free_addresses(xprt);
311
312 xprt_free(xprt);
313
314 dprintk("RPC: %s: returning\n", __func__);
315
316 module_put(THIS_MODULE);
317 }
318
319 static const struct rpc_timeout xprt_rdma_default_timeout = {
320 .to_initval = 60 * HZ,
321 .to_maxval = 60 * HZ,
322 };
323
324 /**
325 * xprt_setup_rdma - Set up transport to use RDMA
326 *
327 * @args: rpc transport arguments
328 */
329 static struct rpc_xprt *
xprt_setup_rdma(struct xprt_create * args)330 xprt_setup_rdma(struct xprt_create *args)
331 {
332 struct rpcrdma_create_data_internal cdata;
333 struct rpc_xprt *xprt;
334 struct rpcrdma_xprt *new_xprt;
335 struct rpcrdma_ep *new_ep;
336 struct sockaddr *sap;
337 int rc;
338
339 if (args->addrlen > sizeof(xprt->addr)) {
340 dprintk("RPC: %s: address too large\n", __func__);
341 return ERR_PTR(-EBADF);
342 }
343
344 xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
345 xprt_rdma_slot_table_entries,
346 xprt_rdma_slot_table_entries);
347 if (xprt == NULL) {
348 dprintk("RPC: %s: couldn't allocate rpcrdma_xprt\n",
349 __func__);
350 return ERR_PTR(-ENOMEM);
351 }
352
353 /* 60 second timeout, no retries */
354 xprt->timeout = &xprt_rdma_default_timeout;
355 xprt->bind_timeout = RPCRDMA_BIND_TO;
356 xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
357 xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
358
359 xprt->resvport = 0; /* privileged port not needed */
360 xprt->tsh_size = 0; /* RPC-RDMA handles framing */
361 xprt->ops = &xprt_rdma_procs;
362
363 /*
364 * Set up RDMA-specific connect data.
365 */
366
367 sap = (struct sockaddr *)&cdata.addr;
368 memcpy(sap, args->dstaddr, args->addrlen);
369
370 /* Ensure xprt->addr holds valid server TCP (not RDMA)
371 * address, for any side protocols which peek at it */
372 xprt->prot = IPPROTO_TCP;
373 xprt->addrlen = args->addrlen;
374 memcpy(&xprt->addr, sap, xprt->addrlen);
375
376 if (rpc_get_port(sap))
377 xprt_set_bound(xprt);
378
379 cdata.max_requests = xprt->max_reqs;
380
381 cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
382 cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
383
384 cdata.inline_wsize = xprt_rdma_max_inline_write;
385 if (cdata.inline_wsize > cdata.wsize)
386 cdata.inline_wsize = cdata.wsize;
387
388 cdata.inline_rsize = xprt_rdma_max_inline_read;
389 if (cdata.inline_rsize > cdata.rsize)
390 cdata.inline_rsize = cdata.rsize;
391
392 cdata.padding = xprt_rdma_inline_write_padding;
393
394 /*
395 * Create new transport instance, which includes initialized
396 * o ia
397 * o endpoint
398 * o buffers
399 */
400
401 new_xprt = rpcx_to_rdmax(xprt);
402
403 rc = rpcrdma_ia_open(new_xprt, sap);
404 if (rc)
405 goto out1;
406
407 /*
408 * initialize and create ep
409 */
410 new_xprt->rx_data = cdata;
411 new_ep = &new_xprt->rx_ep;
412 new_ep->rep_remote_addr = cdata.addr;
413
414 rc = rpcrdma_ep_create(&new_xprt->rx_ep,
415 &new_xprt->rx_ia, &new_xprt->rx_data);
416 if (rc)
417 goto out2;
418
419 /*
420 * Allocate pre-registered send and receive buffers for headers and
421 * any inline data. Also specify any padding which will be provided
422 * from a preregistered zero buffer.
423 */
424 rc = rpcrdma_buffer_create(new_xprt);
425 if (rc)
426 goto out3;
427
428 /*
429 * Register a callback for connection events. This is necessary because
430 * connection loss notification is async. We also catch connection loss
431 * when reaping receives.
432 */
433 INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
434 xprt_rdma_connect_worker);
435
436 xprt_rdma_format_addresses(xprt, sap);
437 xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
438 if (xprt->max_payload == 0)
439 goto out4;
440 xprt->max_payload <<= PAGE_SHIFT;
441 dprintk("RPC: %s: transport data payload maximum: %zu bytes\n",
442 __func__, xprt->max_payload);
443
444 if (!try_module_get(THIS_MODULE))
445 goto out4;
446
447 dprintk("RPC: %s: %s:%s\n", __func__,
448 xprt->address_strings[RPC_DISPLAY_ADDR],
449 xprt->address_strings[RPC_DISPLAY_PORT]);
450 return xprt;
451
452 out4:
453 xprt_rdma_free_addresses(xprt);
454 rc = -EINVAL;
455 out3:
456 rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
457 out2:
458 rpcrdma_ia_close(&new_xprt->rx_ia);
459 out1:
460 xprt_free(xprt);
461 return ERR_PTR(rc);
462 }
463
464 /**
465 * xprt_rdma_close - Close down RDMA connection
466 * @xprt: generic transport to be closed
467 *
468 * Called during transport shutdown reconnect, or device
469 * removal. Caller holds the transport's write lock.
470 */
471 static void
xprt_rdma_close(struct rpc_xprt * xprt)472 xprt_rdma_close(struct rpc_xprt *xprt)
473 {
474 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
475 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
476 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
477
478 dprintk("RPC: %s: closing xprt %p\n", __func__, xprt);
479
480 if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
481 xprt_clear_connected(xprt);
482 rpcrdma_ia_remove(ia);
483 return;
484 }
485 if (ep->rep_connected == -ENODEV)
486 return;
487 if (ep->rep_connected > 0)
488 xprt->reestablish_timeout = 0;
489 xprt_disconnect_done(xprt);
490 rpcrdma_ep_disconnect(ep, ia);
491 }
492
493 static void
xprt_rdma_set_port(struct rpc_xprt * xprt,u16 port)494 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
495 {
496 struct sockaddr_in *sap;
497
498 sap = (struct sockaddr_in *)&xprt->addr;
499 sap->sin_port = htons(port);
500 sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
501 sap->sin_port = htons(port);
502 dprintk("RPC: %s: %u\n", __func__, port);
503 }
504
505 /**
506 * xprt_rdma_timer - invoked when an RPC times out
507 * @xprt: controlling RPC transport
508 * @task: RPC task that timed out
509 *
510 * Invoked when the transport is still connected, but an RPC
511 * retransmit timeout occurs.
512 *
513 * Since RDMA connections don't have a keep-alive, forcibly
514 * disconnect and retry to connect. This drives full
515 * detection of the network path, and retransmissions of
516 * all pending RPCs.
517 */
518 static void
xprt_rdma_timer(struct rpc_xprt * xprt,struct rpc_task * task)519 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
520 {
521 dprintk("RPC: %5u %s: xprt = %p\n", task->tk_pid, __func__, xprt);
522
523 xprt_force_disconnect(xprt);
524 }
525
526 static void
xprt_rdma_connect(struct rpc_xprt * xprt,struct rpc_task * task)527 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
528 {
529 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
530
531 if (r_xprt->rx_ep.rep_connected != 0) {
532 /* Reconnect */
533 schedule_delayed_work(&r_xprt->rx_connect_worker,
534 xprt->reestablish_timeout);
535 xprt->reestablish_timeout <<= 1;
536 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
537 xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
538 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
539 xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
540 } else {
541 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
542 if (!RPC_IS_ASYNC(task))
543 flush_delayed_work(&r_xprt->rx_connect_worker);
544 }
545 }
546
547 /* Allocate a fixed-size buffer in which to construct and send the
548 * RPC-over-RDMA header for this request.
549 */
550 static bool
rpcrdma_get_rdmabuf(struct rpcrdma_xprt * r_xprt,struct rpcrdma_req * req,gfp_t flags)551 rpcrdma_get_rdmabuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
552 gfp_t flags)
553 {
554 size_t size = RPCRDMA_HDRBUF_SIZE;
555 struct rpcrdma_regbuf *rb;
556
557 if (req->rl_rdmabuf)
558 return true;
559
560 rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
561 if (IS_ERR(rb))
562 return false;
563
564 r_xprt->rx_stats.hardway_register_count += size;
565 req->rl_rdmabuf = rb;
566 xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
567 return true;
568 }
569
570 static bool
rpcrdma_get_sendbuf(struct rpcrdma_xprt * r_xprt,struct rpcrdma_req * req,size_t size,gfp_t flags)571 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
572 size_t size, gfp_t flags)
573 {
574 struct rpcrdma_regbuf *rb;
575
576 if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
577 return true;
578
579 rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
580 if (IS_ERR(rb))
581 return false;
582
583 rpcrdma_free_regbuf(req->rl_sendbuf);
584 r_xprt->rx_stats.hardway_register_count += size;
585 req->rl_sendbuf = rb;
586 return true;
587 }
588
589 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
590 * The decision to use a Reply chunk is made later in
591 * rpcrdma_marshal_req. This buffer is registered at that time.
592 *
593 * Otherwise, the associated RPC Reply arrives in a separate
594 * Receive buffer, arbitrarily chosen by the HCA. The buffer
595 * allocated here for the RPC Reply is not utilized in that
596 * case. See rpcrdma_inline_fixup.
597 *
598 * A regbuf is used here to remember the buffer size.
599 */
600 static bool
rpcrdma_get_recvbuf(struct rpcrdma_xprt * r_xprt,struct rpcrdma_req * req,size_t size,gfp_t flags)601 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
602 size_t size, gfp_t flags)
603 {
604 struct rpcrdma_regbuf *rb;
605
606 if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
607 return true;
608
609 rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
610 if (IS_ERR(rb))
611 return false;
612
613 rpcrdma_free_regbuf(req->rl_recvbuf);
614 r_xprt->rx_stats.hardway_register_count += size;
615 req->rl_recvbuf = rb;
616 return true;
617 }
618
619 /**
620 * xprt_rdma_allocate - allocate transport resources for an RPC
621 * @task: RPC task
622 *
623 * Return values:
624 * 0: Success; rq_buffer points to RPC buffer to use
625 * ENOMEM: Out of memory, call again later
626 * EIO: A permanent error occurred, do not retry
627 *
628 * The RDMA allocate/free functions need the task structure as a place
629 * to hide the struct rpcrdma_req, which is necessary for the actual
630 * send/recv sequence.
631 *
632 * xprt_rdma_allocate provides buffers that are already mapped for
633 * DMA, and a local DMA lkey is provided for each.
634 */
635 static int
xprt_rdma_allocate(struct rpc_task * task)636 xprt_rdma_allocate(struct rpc_task *task)
637 {
638 struct rpc_rqst *rqst = task->tk_rqstp;
639 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
640 struct rpcrdma_req *req;
641 gfp_t flags;
642
643 req = rpcrdma_buffer_get(&r_xprt->rx_buf);
644 if (req == NULL)
645 return -ENOMEM;
646
647 flags = RPCRDMA_DEF_GFP;
648 if (RPC_IS_SWAPPER(task))
649 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
650
651 if (!rpcrdma_get_rdmabuf(r_xprt, req, flags))
652 goto out_fail;
653 if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
654 goto out_fail;
655 if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
656 goto out_fail;
657
658 dprintk("RPC: %5u %s: send size = %zd, recv size = %zd, req = %p\n",
659 task->tk_pid, __func__, rqst->rq_callsize,
660 rqst->rq_rcvsize, req);
661
662 req->rl_connect_cookie = 0; /* our reserved value */
663 rpcrdma_set_xprtdata(rqst, req);
664 rqst->rq_buffer = req->rl_sendbuf->rg_base;
665 rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
666 return 0;
667
668 out_fail:
669 rpcrdma_buffer_put(req);
670 return -ENOMEM;
671 }
672
673 /**
674 * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
675 * @task: RPC task
676 *
677 * Caller guarantees rqst->rq_buffer is non-NULL.
678 */
679 static void
xprt_rdma_free(struct rpc_task * task)680 xprt_rdma_free(struct rpc_task *task)
681 {
682 struct rpc_rqst *rqst = task->tk_rqstp;
683 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
684 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
685 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
686
687 if (req->rl_backchannel)
688 return;
689
690 dprintk("RPC: %s: called on 0x%p\n", __func__, req->rl_reply);
691
692 if (!list_empty(&req->rl_registered))
693 ia->ri_ops->ro_unmap_sync(r_xprt, &req->rl_registered);
694 rpcrdma_unmap_sges(ia, req);
695 rpcrdma_buffer_put(req);
696 }
697
698 /**
699 * xprt_rdma_send_request - marshal and send an RPC request
700 * @task: RPC task with an RPC message in rq_snd_buf
701 *
702 * Caller holds the transport's write lock.
703 *
704 * Return values:
705 * 0: The request has been sent
706 * ENOTCONN: Caller needs to invoke connect logic then call again
707 * ENOBUFS: Call again later to send the request
708 * EIO: A permanent error occurred. The request was not sent,
709 * and don't try it again
710 *
711 * send_request invokes the meat of RPC RDMA. It must do the following:
712 *
713 * 1. Marshal the RPC request into an RPC RDMA request, which means
714 * putting a header in front of data, and creating IOVs for RDMA
715 * from those in the request.
716 * 2. In marshaling, detect opportunities for RDMA, and use them.
717 * 3. Post a recv message to set up asynch completion, then send
718 * the request (rpcrdma_ep_post).
719 * 4. No partial sends are possible in the RPC-RDMA protocol (as in UDP).
720 */
721 static int
xprt_rdma_send_request(struct rpc_task * task)722 xprt_rdma_send_request(struct rpc_task *task)
723 {
724 struct rpc_rqst *rqst = task->tk_rqstp;
725 struct rpc_xprt *xprt = rqst->rq_xprt;
726 struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
727 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
728 int rc = 0;
729
730 if (!xprt_connected(xprt))
731 goto drop_connection;
732
733 /* On retransmit, remove any previously registered chunks */
734 if (unlikely(!list_empty(&req->rl_registered)))
735 r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
736
737 rc = rpcrdma_marshal_req(r_xprt, rqst);
738 if (rc < 0)
739 goto failed_marshal;
740
741 if (req->rl_reply == NULL) /* e.g. reconnection */
742 rpcrdma_recv_buffer_get(req);
743
744 /* Must suppress retransmit to maintain credits */
745 if (req->rl_connect_cookie == xprt->connect_cookie)
746 goto drop_connection;
747 req->rl_connect_cookie = xprt->connect_cookie;
748
749 if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
750 goto drop_connection;
751
752 rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
753 rqst->rq_bytes_sent = 0;
754 return 0;
755
756 failed_marshal:
757 if (rc != -ENOTCONN)
758 return rc;
759 drop_connection:
760 xprt_disconnect_done(xprt);
761 return -ENOTCONN; /* implies disconnect */
762 }
763
xprt_rdma_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)764 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
765 {
766 struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
767 long idle_time = 0;
768
769 if (xprt_connected(xprt))
770 idle_time = (long)(jiffies - xprt->last_used) / HZ;
771
772 seq_puts(seq, "\txprt:\trdma ");
773 seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
774 0, /* need a local port? */
775 xprt->stat.bind_count,
776 xprt->stat.connect_count,
777 xprt->stat.connect_time,
778 idle_time,
779 xprt->stat.sends,
780 xprt->stat.recvs,
781 xprt->stat.bad_xids,
782 xprt->stat.req_u,
783 xprt->stat.bklog_u);
784 seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
785 r_xprt->rx_stats.read_chunk_count,
786 r_xprt->rx_stats.write_chunk_count,
787 r_xprt->rx_stats.reply_chunk_count,
788 r_xprt->rx_stats.total_rdma_request,
789 r_xprt->rx_stats.total_rdma_reply,
790 r_xprt->rx_stats.pullup_copy_count,
791 r_xprt->rx_stats.fixup_copy_count,
792 r_xprt->rx_stats.hardway_register_count,
793 r_xprt->rx_stats.failed_marshal_count,
794 r_xprt->rx_stats.bad_reply_count,
795 r_xprt->rx_stats.nomsg_call_count);
796 seq_printf(seq, "%lu %lu %lu %lu\n",
797 r_xprt->rx_stats.mrs_recovered,
798 r_xprt->rx_stats.mrs_orphaned,
799 r_xprt->rx_stats.mrs_allocated,
800 r_xprt->rx_stats.local_inv_needed);
801 }
802
803 static int
xprt_rdma_enable_swap(struct rpc_xprt * xprt)804 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
805 {
806 return 0;
807 }
808
809 static void
xprt_rdma_disable_swap(struct rpc_xprt * xprt)810 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
811 {
812 }
813
814 /*
815 * Plumbing for rpc transport switch and kernel module
816 */
817
818 static const struct rpc_xprt_ops xprt_rdma_procs = {
819 .reserve_xprt = xprt_reserve_xprt_cong,
820 .release_xprt = xprt_release_xprt_cong, /* sunrpc/xprt.c */
821 .alloc_slot = xprt_alloc_slot,
822 .release_request = xprt_release_rqst_cong, /* ditto */
823 .set_retrans_timeout = xprt_set_retrans_timeout_def, /* ditto */
824 .timer = xprt_rdma_timer,
825 .rpcbind = rpcb_getport_async, /* sunrpc/rpcb_clnt.c */
826 .set_port = xprt_rdma_set_port,
827 .connect = xprt_rdma_connect,
828 .buf_alloc = xprt_rdma_allocate,
829 .buf_free = xprt_rdma_free,
830 .send_request = xprt_rdma_send_request,
831 .close = xprt_rdma_close,
832 .destroy = xprt_rdma_destroy,
833 .print_stats = xprt_rdma_print_stats,
834 .enable_swap = xprt_rdma_enable_swap,
835 .disable_swap = xprt_rdma_disable_swap,
836 .inject_disconnect = xprt_rdma_inject_disconnect,
837 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
838 .bc_setup = xprt_rdma_bc_setup,
839 .bc_up = xprt_rdma_bc_up,
840 .bc_maxpayload = xprt_rdma_bc_maxpayload,
841 .bc_free_rqst = xprt_rdma_bc_free_rqst,
842 .bc_destroy = xprt_rdma_bc_destroy,
843 #endif
844 };
845
846 static struct xprt_class xprt_rdma = {
847 .list = LIST_HEAD_INIT(xprt_rdma.list),
848 .name = "rdma",
849 .owner = THIS_MODULE,
850 .ident = XPRT_TRANSPORT_RDMA,
851 .setup = xprt_setup_rdma,
852 };
853
xprt_rdma_cleanup(void)854 void xprt_rdma_cleanup(void)
855 {
856 int rc;
857
858 dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
859 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
860 if (sunrpc_table_header) {
861 unregister_sysctl_table(sunrpc_table_header);
862 sunrpc_table_header = NULL;
863 }
864 #endif
865 rc = xprt_unregister_transport(&xprt_rdma);
866 if (rc)
867 dprintk("RPC: %s: xprt_unregister returned %i\n",
868 __func__, rc);
869
870 rpcrdma_destroy_wq();
871
872 rc = xprt_unregister_transport(&xprt_rdma_bc);
873 if (rc)
874 dprintk("RPC: %s: xprt_unregister(bc) returned %i\n",
875 __func__, rc);
876 }
877
xprt_rdma_init(void)878 int xprt_rdma_init(void)
879 {
880 int rc;
881
882 rc = rpcrdma_alloc_wq();
883 if (rc)
884 return rc;
885
886 rc = xprt_register_transport(&xprt_rdma);
887 if (rc) {
888 rpcrdma_destroy_wq();
889 return rc;
890 }
891
892 rc = xprt_register_transport(&xprt_rdma_bc);
893 if (rc) {
894 xprt_unregister_transport(&xprt_rdma);
895 rpcrdma_destroy_wq();
896 return rc;
897 }
898
899 dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
900
901 dprintk("Defaults:\n");
902 dprintk("\tSlots %d\n"
903 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
904 xprt_rdma_slot_table_entries,
905 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
906 dprintk("\tPadding %d\n\tMemreg %d\n",
907 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
908
909 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
910 if (!sunrpc_table_header)
911 sunrpc_table_header = register_sysctl_table(sunrpc_table);
912 #endif
913 return 0;
914 }
915