1
2
3
4
5
6
7
8
9
10
11
12
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/in.h>
17#include <linux/module.h>
18#include <linux/net.h>
19#include <linux/ipv6.h>
20#include <linux/kthread.h>
21#include <linux/errno.h>
22#include <linux/kernel.h>
23#include <linux/un.h>
24#include <linux/uaccess.h>
25#include <linux/inet.h>
26#include <linux/idr.h>
27#include <linux/file.h>
28#include <linux/parser.h>
29#include <linux/semaphore.h>
30#include <linux/slab.h>
31#include <linux/seq_file.h>
32#include <net/9p/9p.h>
33#include <net/9p/client.h>
34#include <net/9p/transport.h>
35#include <rdma/ib_verbs.h>
36#include <rdma/rdma_cm.h>
37
38#define P9_PORT 5640
39#define P9_RDMA_SQ_DEPTH 32
40#define P9_RDMA_RQ_DEPTH 32
41#define P9_RDMA_SEND_SGE 4
42#define P9_RDMA_RECV_SGE 4
43#define P9_RDMA_IRD 0
44#define P9_RDMA_ORD 0
45#define P9_RDMA_TIMEOUT 30000
46#define P9_RDMA_MAXSIZE (1024*1024)
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69struct p9_trans_rdma {
70 enum {
71 P9_RDMA_INIT,
72 P9_RDMA_ADDR_RESOLVED,
73 P9_RDMA_ROUTE_RESOLVED,
74 P9_RDMA_CONNECTED,
75 P9_RDMA_FLUSHING,
76 P9_RDMA_CLOSING,
77 P9_RDMA_CLOSED,
78 } state;
79 struct rdma_cm_id *cm_id;
80 struct ib_pd *pd;
81 struct ib_qp *qp;
82 struct ib_cq *cq;
83 long timeout;
84 bool privport;
85 u16 port;
86 int sq_depth;
87 struct semaphore sq_sem;
88 int rq_depth;
89 struct semaphore rq_sem;
90 atomic_t excess_rc;
91 struct sockaddr_in addr;
92 spinlock_t req_lock;
93
94 struct completion cm_done;
95};
96
97struct p9_rdma_req;
98
99
100
101
102
103
104
105
106struct p9_rdma_context {
107 struct ib_cqe cqe;
108 dma_addr_t busa;
109 union {
110 struct p9_req_t *req;
111 struct p9_fcall rc;
112 };
113};
114
115
116
117
118
119
120
121
122
123struct p9_rdma_opts {
124 short port;
125 bool privport;
126 int sq_depth;
127 int rq_depth;
128 long timeout;
129};
130
131
132
133
134enum {
135
136 Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
137
138 Opt_privport,
139 Opt_err,
140};
141
142static match_table_t tokens = {
143 {Opt_port, "port=%u"},
144 {Opt_sq_depth, "sq=%u"},
145 {Opt_rq_depth, "rq=%u"},
146 {Opt_timeout, "timeout=%u"},
147 {Opt_privport, "privport"},
148 {Opt_err, NULL},
149};
150
151static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
152{
153 struct p9_trans_rdma *rdma = clnt->trans;
154
155 if (rdma->port != P9_PORT)
156 seq_printf(m, ",port=%u", rdma->port);
157 if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
158 seq_printf(m, ",sq=%u", rdma->sq_depth);
159 if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
160 seq_printf(m, ",rq=%u", rdma->rq_depth);
161 if (rdma->timeout != P9_RDMA_TIMEOUT)
162 seq_printf(m, ",timeout=%lu", rdma->timeout);
163 if (rdma->privport)
164 seq_puts(m, ",privport");
165 return 0;
166}
167
168
169
170
171
172
173
174
175static int parse_opts(char *params, struct p9_rdma_opts *opts)
176{
177 char *p;
178 substring_t args[MAX_OPT_ARGS];
179 int option;
180 char *options, *tmp_options;
181
182 opts->port = P9_PORT;
183 opts->sq_depth = P9_RDMA_SQ_DEPTH;
184 opts->rq_depth = P9_RDMA_RQ_DEPTH;
185 opts->timeout = P9_RDMA_TIMEOUT;
186 opts->privport = false;
187
188 if (!params)
189 return 0;
190
191 tmp_options = kstrdup(params, GFP_KERNEL);
192 if (!tmp_options) {
193 p9_debug(P9_DEBUG_ERROR,
194 "failed to allocate copy of option string\n");
195 return -ENOMEM;
196 }
197 options = tmp_options;
198
199 while ((p = strsep(&options, ",")) != NULL) {
200 int token;
201 int r;
202 if (!*p)
203 continue;
204 token = match_token(p, tokens, args);
205 if ((token != Opt_err) && (token != Opt_privport)) {
206 r = match_int(&args[0], &option);
207 if (r < 0) {
208 p9_debug(P9_DEBUG_ERROR,
209 "integer field, but no integer?\n");
210 continue;
211 }
212 }
213 switch (token) {
214 case Opt_port:
215 opts->port = option;
216 break;
217 case Opt_sq_depth:
218 opts->sq_depth = option;
219 break;
220 case Opt_rq_depth:
221 opts->rq_depth = option;
222 break;
223 case Opt_timeout:
224 opts->timeout = option;
225 break;
226 case Opt_privport:
227 opts->privport = true;
228 break;
229 default:
230 continue;
231 }
232 }
233
234 opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
235 kfree(tmp_options);
236 return 0;
237}
238
239static int
240p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
241{
242 struct p9_client *c = id->context;
243 struct p9_trans_rdma *rdma = c->trans;
244 switch (event->event) {
245 case RDMA_CM_EVENT_ADDR_RESOLVED:
246 BUG_ON(rdma->state != P9_RDMA_INIT);
247 rdma->state = P9_RDMA_ADDR_RESOLVED;
248 break;
249
250 case RDMA_CM_EVENT_ROUTE_RESOLVED:
251 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
252 rdma->state = P9_RDMA_ROUTE_RESOLVED;
253 break;
254
255 case RDMA_CM_EVENT_ESTABLISHED:
256 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
257 rdma->state = P9_RDMA_CONNECTED;
258 break;
259
260 case RDMA_CM_EVENT_DISCONNECTED:
261 if (rdma)
262 rdma->state = P9_RDMA_CLOSED;
263 c->status = Disconnected;
264 break;
265
266 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
267 break;
268
269 case RDMA_CM_EVENT_ADDR_CHANGE:
270 case RDMA_CM_EVENT_ROUTE_ERROR:
271 case RDMA_CM_EVENT_DEVICE_REMOVAL:
272 case RDMA_CM_EVENT_MULTICAST_JOIN:
273 case RDMA_CM_EVENT_MULTICAST_ERROR:
274 case RDMA_CM_EVENT_REJECTED:
275 case RDMA_CM_EVENT_CONNECT_REQUEST:
276 case RDMA_CM_EVENT_CONNECT_RESPONSE:
277 case RDMA_CM_EVENT_CONNECT_ERROR:
278 case RDMA_CM_EVENT_ADDR_ERROR:
279 case RDMA_CM_EVENT_UNREACHABLE:
280 c->status = Disconnected;
281 rdma_disconnect(rdma->cm_id);
282 break;
283 default:
284 BUG();
285 }
286 complete(&rdma->cm_done);
287 return 0;
288}
289
290static void
291recv_done(struct ib_cq *cq, struct ib_wc *wc)
292{
293 struct p9_client *client = cq->cq_context;
294 struct p9_trans_rdma *rdma = client->trans;
295 struct p9_rdma_context *c =
296 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
297 struct p9_req_t *req;
298 int err = 0;
299 int16_t tag;
300
301 req = NULL;
302 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
303 DMA_FROM_DEVICE);
304
305 if (wc->status != IB_WC_SUCCESS)
306 goto err_out;
307
308 c->rc.size = wc->byte_len;
309 err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1);
310 if (err)
311 goto err_out;
312
313 req = p9_tag_lookup(client, tag);
314 if (!req)
315 goto err_out;
316
317
318
319 if (unlikely(req->rc.sdata)) {
320 pr_err("Duplicate reply for request %d", tag);
321 goto err_out;
322 }
323
324 req->rc.size = c->rc.size;
325 req->rc.sdata = c->rc.sdata;
326 p9_client_cb(client, req, REQ_STATUS_RCVD);
327
328 out:
329 up(&rdma->rq_sem);
330 kfree(c);
331 return;
332
333 err_out:
334 p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
335 req, err, wc->status);
336 rdma->state = P9_RDMA_FLUSHING;
337 client->status = Disconnected;
338 goto out;
339}
340
341static void
342send_done(struct ib_cq *cq, struct ib_wc *wc)
343{
344 struct p9_client *client = cq->cq_context;
345 struct p9_trans_rdma *rdma = client->trans;
346 struct p9_rdma_context *c =
347 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
348
349 ib_dma_unmap_single(rdma->cm_id->device,
350 c->busa, c->req->tc.size,
351 DMA_TO_DEVICE);
352 up(&rdma->sq_sem);
353 p9_req_put(c->req);
354 kfree(c);
355}
356
357static void qp_event_handler(struct ib_event *event, void *context)
358{
359 p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
360 event->event, context);
361}
362
363static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
364{
365 if (!rdma)
366 return;
367
368 if (rdma->qp && !IS_ERR(rdma->qp))
369 ib_destroy_qp(rdma->qp);
370
371 if (rdma->pd && !IS_ERR(rdma->pd))
372 ib_dealloc_pd(rdma->pd);
373
374 if (rdma->cq && !IS_ERR(rdma->cq))
375 ib_free_cq(rdma->cq);
376
377 if (rdma->cm_id && !IS_ERR(rdma->cm_id))
378 rdma_destroy_id(rdma->cm_id);
379
380 kfree(rdma);
381}
382
383static int
384post_recv(struct p9_client *client, struct p9_rdma_context *c)
385{
386 struct p9_trans_rdma *rdma = client->trans;
387 struct ib_recv_wr wr;
388 struct ib_sge sge;
389
390 c->busa = ib_dma_map_single(rdma->cm_id->device,
391 c->rc.sdata, client->msize,
392 DMA_FROM_DEVICE);
393 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
394 goto error;
395
396 c->cqe.done = recv_done;
397
398 sge.addr = c->busa;
399 sge.length = client->msize;
400 sge.lkey = rdma->pd->local_dma_lkey;
401
402 wr.next = NULL;
403 wr.wr_cqe = &c->cqe;
404 wr.sg_list = &sge;
405 wr.num_sge = 1;
406 return ib_post_recv(rdma->qp, &wr, NULL);
407
408 error:
409 p9_debug(P9_DEBUG_ERROR, "EIO\n");
410 return -EIO;
411}
412
413static int rdma_request(struct p9_client *client, struct p9_req_t *req)
414{
415 struct p9_trans_rdma *rdma = client->trans;
416 struct ib_send_wr wr;
417 struct ib_sge sge;
418 int err = 0;
419 unsigned long flags;
420 struct p9_rdma_context *c = NULL;
421 struct p9_rdma_context *rpl_context = NULL;
422
423
424
425
426
427
428
429
430
431 if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
432 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
433
434 p9_fcall_fini(&req->rc);
435 req->rc.sdata = NULL;
436 goto dont_need_post_recv;
437 } else {
438
439 atomic_inc(&rdma->excess_rc);
440 }
441 }
442
443
444 rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
445 if (!rpl_context) {
446 err = -ENOMEM;
447 goto recv_error;
448 }
449 rpl_context->rc.sdata = req->rc.sdata;
450
451
452
453
454
455
456
457
458 if (down_interruptible(&rdma->rq_sem)) {
459 err = -EINTR;
460 goto recv_error;
461 }
462
463 err = post_recv(client, rpl_context);
464 if (err) {
465 p9_debug(P9_DEBUG_ERROR, "POST RECV failed: %d\n", err);
466 goto recv_error;
467 }
468
469 req->rc.sdata = NULL;
470
471dont_need_post_recv:
472
473 c = kmalloc(sizeof *c, GFP_NOFS);
474 if (!c) {
475 err = -ENOMEM;
476 goto send_error;
477 }
478 c->req = req;
479
480 c->busa = ib_dma_map_single(rdma->cm_id->device,
481 c->req->tc.sdata, c->req->tc.size,
482 DMA_TO_DEVICE);
483 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
484 err = -EIO;
485 goto send_error;
486 }
487
488 c->cqe.done = send_done;
489
490 sge.addr = c->busa;
491 sge.length = c->req->tc.size;
492 sge.lkey = rdma->pd->local_dma_lkey;
493
494 wr.next = NULL;
495 wr.wr_cqe = &c->cqe;
496 wr.opcode = IB_WR_SEND;
497 wr.send_flags = IB_SEND_SIGNALED;
498 wr.sg_list = &sge;
499 wr.num_sge = 1;
500
501 if (down_interruptible(&rdma->sq_sem)) {
502 err = -EINTR;
503 goto send_error;
504 }
505
506
507
508
509
510 req->status = REQ_STATUS_SENT;
511 err = ib_post_send(rdma->qp, &wr, NULL);
512 if (err)
513 goto send_error;
514
515
516 return 0;
517
518
519 send_error:
520 req->status = REQ_STATUS_ERROR;
521 kfree(c);
522 p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
523
524
525
526
527 atomic_inc(&rdma->excess_rc);
528 return err;
529
530
531 recv_error:
532 kfree(rpl_context);
533 spin_lock_irqsave(&rdma->req_lock, flags);
534 if (err != -EINTR && rdma->state < P9_RDMA_CLOSING) {
535 rdma->state = P9_RDMA_CLOSING;
536 spin_unlock_irqrestore(&rdma->req_lock, flags);
537 rdma_disconnect(rdma->cm_id);
538 } else
539 spin_unlock_irqrestore(&rdma->req_lock, flags);
540 return err;
541}
542
543static void rdma_close(struct p9_client *client)
544{
545 struct p9_trans_rdma *rdma;
546
547 if (!client)
548 return;
549
550 rdma = client->trans;
551 if (!rdma)
552 return;
553
554 client->status = Disconnected;
555 rdma_disconnect(rdma->cm_id);
556 rdma_destroy_trans(rdma);
557}
558
559
560
561
562
563static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
564{
565 struct p9_trans_rdma *rdma;
566
567 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
568 if (!rdma)
569 return NULL;
570
571 rdma->port = opts->port;
572 rdma->privport = opts->privport;
573 rdma->sq_depth = opts->sq_depth;
574 rdma->rq_depth = opts->rq_depth;
575 rdma->timeout = opts->timeout;
576 spin_lock_init(&rdma->req_lock);
577 init_completion(&rdma->cm_done);
578 sema_init(&rdma->sq_sem, rdma->sq_depth);
579 sema_init(&rdma->rq_sem, rdma->rq_depth);
580 atomic_set(&rdma->excess_rc, 0);
581
582 return rdma;
583}
584
585static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
586{
587
588
589
590 return 1;
591}
592
593
594
595
596static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
597{
598 struct p9_trans_rdma *rdma = client->trans;
599 atomic_inc(&rdma->excess_rc);
600 return 0;
601}
602
603static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
604{
605 struct sockaddr_in cl = {
606 .sin_family = AF_INET,
607 .sin_addr.s_addr = htonl(INADDR_ANY),
608 };
609 int port, err = -EINVAL;
610
611 for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
612 cl.sin_port = htons((ushort)port);
613 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
614 if (err != -EADDRINUSE)
615 break;
616 }
617 return err;
618}
619
620
621
622
623
624
625
626static int
627rdma_create_trans(struct p9_client *client, const char *addr, char *args)
628{
629 int err;
630 struct p9_rdma_opts opts;
631 struct p9_trans_rdma *rdma;
632 struct rdma_conn_param conn_param;
633 struct ib_qp_init_attr qp_attr;
634
635 if (addr == NULL)
636 return -EINVAL;
637
638
639 err = parse_opts(args, &opts);
640 if (err < 0)
641 return err;
642
643
644 rdma = alloc_rdma(&opts);
645 if (!rdma)
646 return -ENOMEM;
647
648
649 rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
650 RDMA_PS_TCP, IB_QPT_RC);
651 if (IS_ERR(rdma->cm_id))
652 goto error;
653
654
655 client->trans = rdma;
656
657
658 if (opts.privport) {
659 err = p9_rdma_bind_privport(rdma);
660 if (err < 0) {
661 pr_err("%s (%d): problem binding to privport: %d\n",
662 __func__, task_pid_nr(current), -err);
663 goto error;
664 }
665 }
666
667
668 rdma->addr.sin_family = AF_INET;
669 rdma->addr.sin_addr.s_addr = in_aton(addr);
670 rdma->addr.sin_port = htons(opts.port);
671 err = rdma_resolve_addr(rdma->cm_id, NULL,
672 (struct sockaddr *)&rdma->addr,
673 rdma->timeout);
674 if (err)
675 goto error;
676 err = wait_for_completion_interruptible(&rdma->cm_done);
677 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
678 goto error;
679
680
681 err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
682 if (err)
683 goto error;
684 err = wait_for_completion_interruptible(&rdma->cm_done);
685 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
686 goto error;
687
688
689 rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
690 opts.sq_depth + opts.rq_depth + 1,
691 IB_POLL_SOFTIRQ);
692 if (IS_ERR(rdma->cq))
693 goto error;
694
695
696 rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
697 if (IS_ERR(rdma->pd))
698 goto error;
699
700
701 memset(&qp_attr, 0, sizeof qp_attr);
702 qp_attr.event_handler = qp_event_handler;
703 qp_attr.qp_context = client;
704 qp_attr.cap.max_send_wr = opts.sq_depth;
705 qp_attr.cap.max_recv_wr = opts.rq_depth;
706 qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
707 qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
708 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
709 qp_attr.qp_type = IB_QPT_RC;
710 qp_attr.send_cq = rdma->cq;
711 qp_attr.recv_cq = rdma->cq;
712 err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
713 if (err)
714 goto error;
715 rdma->qp = rdma->cm_id->qp;
716
717
718 memset(&conn_param, 0, sizeof(conn_param));
719 conn_param.private_data = NULL;
720 conn_param.private_data_len = 0;
721 conn_param.responder_resources = P9_RDMA_IRD;
722 conn_param.initiator_depth = P9_RDMA_ORD;
723 err = rdma_connect(rdma->cm_id, &conn_param);
724 if (err)
725 goto error;
726 err = wait_for_completion_interruptible(&rdma->cm_done);
727 if (err || (rdma->state != P9_RDMA_CONNECTED))
728 goto error;
729
730 client->status = Connected;
731
732 return 0;
733
734error:
735 rdma_destroy_trans(rdma);
736 return -ENOTCONN;
737}
738
739static struct p9_trans_module p9_rdma_trans = {
740 .name = "rdma",
741 .maxsize = P9_RDMA_MAXSIZE,
742 .def = 0,
743 .owner = THIS_MODULE,
744 .create = rdma_create_trans,
745 .close = rdma_close,
746 .request = rdma_request,
747 .cancel = rdma_cancel,
748 .cancelled = rdma_cancelled,
749 .show_options = p9_rdma_show_options,
750};
751
752
753
754
755static int __init p9_trans_rdma_init(void)
756{
757 v9fs_register_trans(&p9_rdma_trans);
758 return 0;
759}
760
761static void __exit p9_trans_rdma_exit(void)
762{
763 v9fs_unregister_trans(&p9_rdma_trans);
764}
765
766module_init(p9_trans_rdma_init);
767module_exit(p9_trans_rdma_exit);
768
769MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
770MODULE_DESCRIPTION("RDMA Transport for 9P");
771MODULE_LICENSE("Dual BSD/GPL");
772