1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/9p/trans_rdma.c
4 *
5 * RDMA transport layer based on the trans_fd.c implementation.
6 *
7 * Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
8 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
9 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
10 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
11 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
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 /* 30 seconds */
46 #define P9_RDMA_MAXSIZE (1024*1024) /* 1MB */
47
48 /**
49 * struct p9_trans_rdma - RDMA transport instance
50 *
51 * @state: tracks the transport state machine for connection setup and tear down
52 * @cm_id: The RDMA CM ID
53 * @pd: Protection Domain pointer
54 * @qp: Queue Pair pointer
55 * @cq: Completion Queue pointer
56 * @timeout: Number of uSecs to wait for connection management events
57 * @privport: Whether a privileged port may be used
58 * @port: The port to use
59 * @sq_depth: The depth of the Send Queue
60 * @sq_sem: Semaphore for the SQ
61 * @rq_depth: The depth of the Receive Queue.
62 * @rq_sem: Semaphore for the RQ
63 * @excess_rc : Amount of posted Receive Contexts without a pending request.
64 * See rdma_request()
65 * @addr: The remote peer's address
66 * @req_lock: Protects the active request list
67 * @cm_done: Completion event for connection management tracking
68 */
69 struct 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
97 struct p9_rdma_req;
98
99 /**
100 * struct p9_rdma_context - Keeps track of in-process WR
101 *
102 * @cqe: completion queue entry
103 * @busa: Bus address to unmap when the WR completes
104 * @req: Keeps track of requests (send)
105 * @rc: Keepts track of replies (receive)
106 */
107 struct p9_rdma_context {
108 struct ib_cqe cqe;
109 dma_addr_t busa;
110 union {
111 struct p9_req_t *req;
112 struct p9_fcall rc;
113 };
114 };
115
116 /**
117 * struct p9_rdma_opts - Collection of mount options
118 * @port: port of connection
119 * @privport: Whether a privileged port may be used
120 * @sq_depth: The requested depth of the SQ. This really doesn't need
121 * to be any deeper than the number of threads used in the client
122 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
123 * @timeout: Time to wait in msecs for CM events
124 */
125 struct p9_rdma_opts {
126 short port;
127 bool privport;
128 int sq_depth;
129 int rq_depth;
130 long timeout;
131 };
132
133 /*
134 * Option Parsing (code inspired by NFS code)
135 */
136 enum {
137 /* Options that take integer arguments */
138 Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
139 /* Options that take no argument */
140 Opt_privport,
141 Opt_err,
142 };
143
144 static match_table_t tokens = {
145 {Opt_port, "port=%u"},
146 {Opt_sq_depth, "sq=%u"},
147 {Opt_rq_depth, "rq=%u"},
148 {Opt_timeout, "timeout=%u"},
149 {Opt_privport, "privport"},
150 {Opt_err, NULL},
151 };
152
p9_rdma_show_options(struct seq_file * m,struct p9_client * clnt)153 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
154 {
155 struct p9_trans_rdma *rdma = clnt->trans;
156
157 if (rdma->port != P9_PORT)
158 seq_printf(m, ",port=%u", rdma->port);
159 if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
160 seq_printf(m, ",sq=%u", rdma->sq_depth);
161 if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
162 seq_printf(m, ",rq=%u", rdma->rq_depth);
163 if (rdma->timeout != P9_RDMA_TIMEOUT)
164 seq_printf(m, ",timeout=%lu", rdma->timeout);
165 if (rdma->privport)
166 seq_puts(m, ",privport");
167 return 0;
168 }
169
170 /**
171 * parse_opts - parse mount options into rdma options structure
172 * @params: options string passed from mount
173 * @opts: rdma transport-specific structure to parse options into
174 *
175 * Returns 0 upon success, -ERRNO upon failure
176 */
parse_opts(char * params,struct p9_rdma_opts * opts)177 static int parse_opts(char *params, struct p9_rdma_opts *opts)
178 {
179 char *p;
180 substring_t args[MAX_OPT_ARGS];
181 int option;
182 char *options, *tmp_options;
183
184 opts->port = P9_PORT;
185 opts->sq_depth = P9_RDMA_SQ_DEPTH;
186 opts->rq_depth = P9_RDMA_RQ_DEPTH;
187 opts->timeout = P9_RDMA_TIMEOUT;
188 opts->privport = false;
189
190 if (!params)
191 return 0;
192
193 tmp_options = kstrdup(params, GFP_KERNEL);
194 if (!tmp_options) {
195 p9_debug(P9_DEBUG_ERROR,
196 "failed to allocate copy of option string\n");
197 return -ENOMEM;
198 }
199 options = tmp_options;
200
201 while ((p = strsep(&options, ",")) != NULL) {
202 int token;
203 int r;
204 if (!*p)
205 continue;
206 token = match_token(p, tokens, args);
207 if ((token != Opt_err) && (token != Opt_privport)) {
208 r = match_int(&args[0], &option);
209 if (r < 0) {
210 p9_debug(P9_DEBUG_ERROR,
211 "integer field, but no integer?\n");
212 continue;
213 }
214 }
215 switch (token) {
216 case Opt_port:
217 opts->port = option;
218 break;
219 case Opt_sq_depth:
220 opts->sq_depth = option;
221 break;
222 case Opt_rq_depth:
223 opts->rq_depth = option;
224 break;
225 case Opt_timeout:
226 opts->timeout = option;
227 break;
228 case Opt_privport:
229 opts->privport = true;
230 break;
231 default:
232 continue;
233 }
234 }
235 /* RQ must be at least as large as the SQ */
236 opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
237 kfree(tmp_options);
238 return 0;
239 }
240
241 static int
p9_cm_event_handler(struct rdma_cm_id * id,struct rdma_cm_event * event)242 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
243 {
244 struct p9_client *c = id->context;
245 struct p9_trans_rdma *rdma = c->trans;
246 switch (event->event) {
247 case RDMA_CM_EVENT_ADDR_RESOLVED:
248 BUG_ON(rdma->state != P9_RDMA_INIT);
249 rdma->state = P9_RDMA_ADDR_RESOLVED;
250 break;
251
252 case RDMA_CM_EVENT_ROUTE_RESOLVED:
253 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
254 rdma->state = P9_RDMA_ROUTE_RESOLVED;
255 break;
256
257 case RDMA_CM_EVENT_ESTABLISHED:
258 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
259 rdma->state = P9_RDMA_CONNECTED;
260 break;
261
262 case RDMA_CM_EVENT_DISCONNECTED:
263 if (rdma)
264 rdma->state = P9_RDMA_CLOSED;
265 c->status = Disconnected;
266 break;
267
268 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
269 break;
270
271 case RDMA_CM_EVENT_ADDR_CHANGE:
272 case RDMA_CM_EVENT_ROUTE_ERROR:
273 case RDMA_CM_EVENT_DEVICE_REMOVAL:
274 case RDMA_CM_EVENT_MULTICAST_JOIN:
275 case RDMA_CM_EVENT_MULTICAST_ERROR:
276 case RDMA_CM_EVENT_REJECTED:
277 case RDMA_CM_EVENT_CONNECT_REQUEST:
278 case RDMA_CM_EVENT_CONNECT_RESPONSE:
279 case RDMA_CM_EVENT_CONNECT_ERROR:
280 case RDMA_CM_EVENT_ADDR_ERROR:
281 case RDMA_CM_EVENT_UNREACHABLE:
282 c->status = Disconnected;
283 rdma_disconnect(rdma->cm_id);
284 break;
285 default:
286 BUG();
287 }
288 complete(&rdma->cm_done);
289 return 0;
290 }
291
292 static void
recv_done(struct ib_cq * cq,struct ib_wc * wc)293 recv_done(struct ib_cq *cq, struct ib_wc *wc)
294 {
295 struct p9_client *client = cq->cq_context;
296 struct p9_trans_rdma *rdma = client->trans;
297 struct p9_rdma_context *c =
298 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
299 struct p9_req_t *req;
300 int err = 0;
301 int16_t tag;
302
303 req = NULL;
304 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
305 DMA_FROM_DEVICE);
306
307 if (wc->status != IB_WC_SUCCESS)
308 goto err_out;
309
310 c->rc.size = wc->byte_len;
311 err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1);
312 if (err)
313 goto err_out;
314
315 req = p9_tag_lookup(client, tag);
316 if (!req)
317 goto err_out;
318
319 /* Check that we have not yet received a reply for this request.
320 */
321 if (unlikely(req->rc.sdata)) {
322 pr_err("Duplicate reply for request %d", tag);
323 goto err_out;
324 }
325
326 req->rc.size = c->rc.size;
327 req->rc.sdata = c->rc.sdata;
328 p9_client_cb(client, req, REQ_STATUS_RCVD);
329
330 out:
331 up(&rdma->rq_sem);
332 kfree(c);
333 return;
334
335 err_out:
336 p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
337 req, err, wc->status);
338 rdma->state = P9_RDMA_FLUSHING;
339 client->status = Disconnected;
340 goto out;
341 }
342
343 static void
send_done(struct ib_cq * cq,struct ib_wc * wc)344 send_done(struct ib_cq *cq, struct ib_wc *wc)
345 {
346 struct p9_client *client = cq->cq_context;
347 struct p9_trans_rdma *rdma = client->trans;
348 struct p9_rdma_context *c =
349 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
350
351 ib_dma_unmap_single(rdma->cm_id->device,
352 c->busa, c->req->tc.size,
353 DMA_TO_DEVICE);
354 up(&rdma->sq_sem);
355 p9_req_put(client, c->req);
356 kfree(c);
357 }
358
qp_event_handler(struct ib_event * event,void * context)359 static void qp_event_handler(struct ib_event *event, void *context)
360 {
361 p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
362 event->event, context);
363 }
364
rdma_destroy_trans(struct p9_trans_rdma * rdma)365 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
366 {
367 if (!rdma)
368 return;
369
370 if (rdma->qp && !IS_ERR(rdma->qp))
371 ib_destroy_qp(rdma->qp);
372
373 if (rdma->pd && !IS_ERR(rdma->pd))
374 ib_dealloc_pd(rdma->pd);
375
376 if (rdma->cq && !IS_ERR(rdma->cq))
377 ib_free_cq(rdma->cq);
378
379 if (rdma->cm_id && !IS_ERR(rdma->cm_id))
380 rdma_destroy_id(rdma->cm_id);
381
382 kfree(rdma);
383 }
384
385 static int
post_recv(struct p9_client * client,struct p9_rdma_context * c)386 post_recv(struct p9_client *client, struct p9_rdma_context *c)
387 {
388 struct p9_trans_rdma *rdma = client->trans;
389 struct ib_recv_wr wr;
390 struct ib_sge sge;
391 int ret;
392
393 c->busa = ib_dma_map_single(rdma->cm_id->device,
394 c->rc.sdata, client->msize,
395 DMA_FROM_DEVICE);
396 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
397 goto error;
398
399 c->cqe.done = recv_done;
400
401 sge.addr = c->busa;
402 sge.length = client->msize;
403 sge.lkey = rdma->pd->local_dma_lkey;
404
405 wr.next = NULL;
406 wr.wr_cqe = &c->cqe;
407 wr.sg_list = &sge;
408 wr.num_sge = 1;
409
410 ret = ib_post_recv(rdma->qp, &wr, NULL);
411 if (ret)
412 ib_dma_unmap_single(rdma->cm_id->device, c->busa,
413 client->msize, DMA_FROM_DEVICE);
414 return ret;
415
416 error:
417 p9_debug(P9_DEBUG_ERROR, "EIO\n");
418 return -EIO;
419 }
420
rdma_request(struct p9_client * client,struct p9_req_t * req)421 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
422 {
423 struct p9_trans_rdma *rdma = client->trans;
424 struct ib_send_wr wr;
425 struct ib_sge sge;
426 int err = 0;
427 unsigned long flags;
428 struct p9_rdma_context *c = NULL;
429 struct p9_rdma_context *rpl_context = NULL;
430
431 /* When an error occurs between posting the recv and the send,
432 * there will be a receive context posted without a pending request.
433 * Since there is no way to "un-post" it, we remember it and skip
434 * post_recv() for the next request.
435 * So here,
436 * see if we are this `next request' and need to absorb an excess rc.
437 * If yes, then drop and free our own, and do not recv_post().
438 **/
439 if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
440 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
441 /* Got one! */
442 p9_fcall_fini(&req->rc);
443 req->rc.sdata = NULL;
444 goto dont_need_post_recv;
445 } else {
446 /* We raced and lost. */
447 atomic_inc(&rdma->excess_rc);
448 }
449 }
450
451 /* Allocate an fcall for the reply */
452 rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
453 if (!rpl_context) {
454 err = -ENOMEM;
455 goto recv_error;
456 }
457 rpl_context->rc.sdata = req->rc.sdata;
458
459 /*
460 * Post a receive buffer for this request. We need to ensure
461 * there is a reply buffer available for every outstanding
462 * request. A flushed request can result in no reply for an
463 * outstanding request, so we must keep a count to avoid
464 * overflowing the RQ.
465 */
466 if (down_interruptible(&rdma->rq_sem)) {
467 err = -EINTR;
468 goto recv_error;
469 }
470
471 err = post_recv(client, rpl_context);
472 if (err) {
473 p9_debug(P9_DEBUG_ERROR, "POST RECV failed: %d\n", err);
474 goto recv_error;
475 }
476 /* remove posted receive buffer from request structure */
477 req->rc.sdata = NULL;
478
479 dont_need_post_recv:
480 /* Post the request */
481 c = kmalloc(sizeof *c, GFP_NOFS);
482 if (!c) {
483 err = -ENOMEM;
484 goto send_error;
485 }
486 c->req = req;
487
488 c->busa = ib_dma_map_single(rdma->cm_id->device,
489 c->req->tc.sdata, c->req->tc.size,
490 DMA_TO_DEVICE);
491 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
492 err = -EIO;
493 goto send_error;
494 }
495
496 c->cqe.done = send_done;
497
498 sge.addr = c->busa;
499 sge.length = c->req->tc.size;
500 sge.lkey = rdma->pd->local_dma_lkey;
501
502 wr.next = NULL;
503 wr.wr_cqe = &c->cqe;
504 wr.opcode = IB_WR_SEND;
505 wr.send_flags = IB_SEND_SIGNALED;
506 wr.sg_list = &sge;
507 wr.num_sge = 1;
508
509 if (down_interruptible(&rdma->sq_sem)) {
510 err = -EINTR;
511 goto dma_unmap;
512 }
513
514 /* Mark request as `sent' *before* we actually send it,
515 * because doing if after could erase the REQ_STATUS_RCVD
516 * status in case of a very fast reply.
517 */
518 req->status = REQ_STATUS_SENT;
519 err = ib_post_send(rdma->qp, &wr, NULL);
520 if (err)
521 goto dma_unmap;
522
523 /* Success */
524 return 0;
525
526 dma_unmap:
527 ib_dma_unmap_single(rdma->cm_id->device, c->busa,
528 c->req->tc.size, DMA_TO_DEVICE);
529 /* Handle errors that happened during or while preparing the send: */
530 send_error:
531 req->status = REQ_STATUS_ERROR;
532 kfree(c);
533 p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
534
535 /* Ach.
536 * We did recv_post(), but not send. We have one recv_post in excess.
537 */
538 atomic_inc(&rdma->excess_rc);
539 return err;
540
541 /* Handle errors that happened during or while preparing post_recv(): */
542 recv_error:
543 kfree(rpl_context);
544 spin_lock_irqsave(&rdma->req_lock, flags);
545 if (err != -EINTR && rdma->state < P9_RDMA_CLOSING) {
546 rdma->state = P9_RDMA_CLOSING;
547 spin_unlock_irqrestore(&rdma->req_lock, flags);
548 rdma_disconnect(rdma->cm_id);
549 } else
550 spin_unlock_irqrestore(&rdma->req_lock, flags);
551 return err;
552 }
553
rdma_close(struct p9_client * client)554 static void rdma_close(struct p9_client *client)
555 {
556 struct p9_trans_rdma *rdma;
557
558 if (!client)
559 return;
560
561 rdma = client->trans;
562 if (!rdma)
563 return;
564
565 client->status = Disconnected;
566 rdma_disconnect(rdma->cm_id);
567 rdma_destroy_trans(rdma);
568 }
569
570 /**
571 * alloc_rdma - Allocate and initialize the rdma transport structure
572 * @opts: Mount options structure
573 */
alloc_rdma(struct p9_rdma_opts * opts)574 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
575 {
576 struct p9_trans_rdma *rdma;
577
578 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
579 if (!rdma)
580 return NULL;
581
582 rdma->port = opts->port;
583 rdma->privport = opts->privport;
584 rdma->sq_depth = opts->sq_depth;
585 rdma->rq_depth = opts->rq_depth;
586 rdma->timeout = opts->timeout;
587 spin_lock_init(&rdma->req_lock);
588 init_completion(&rdma->cm_done);
589 sema_init(&rdma->sq_sem, rdma->sq_depth);
590 sema_init(&rdma->rq_sem, rdma->rq_depth);
591 atomic_set(&rdma->excess_rc, 0);
592
593 return rdma;
594 }
595
rdma_cancel(struct p9_client * client,struct p9_req_t * req)596 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
597 {
598 /* Nothing to do here.
599 * We will take care of it (if we have to) in rdma_cancelled()
600 */
601 return 1;
602 }
603
604 /* A request has been fully flushed without a reply.
605 * That means we have posted one buffer in excess.
606 */
rdma_cancelled(struct p9_client * client,struct p9_req_t * req)607 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
608 {
609 struct p9_trans_rdma *rdma = client->trans;
610 atomic_inc(&rdma->excess_rc);
611 return 0;
612 }
613
p9_rdma_bind_privport(struct p9_trans_rdma * rdma)614 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
615 {
616 struct sockaddr_in cl = {
617 .sin_family = AF_INET,
618 .sin_addr.s_addr = htonl(INADDR_ANY),
619 };
620 int port, err = -EINVAL;
621
622 for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
623 cl.sin_port = htons((ushort)port);
624 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
625 if (err != -EADDRINUSE)
626 break;
627 }
628 return err;
629 }
630
631 /**
632 * rdma_create_trans - Transport method for creating a transport instance
633 * @client: client instance
634 * @addr: IP address string
635 * @args: Mount options string
636 */
637 static int
rdma_create_trans(struct p9_client * client,const char * addr,char * args)638 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
639 {
640 int err;
641 struct p9_rdma_opts opts;
642 struct p9_trans_rdma *rdma;
643 struct rdma_conn_param conn_param;
644 struct ib_qp_init_attr qp_attr;
645
646 if (addr == NULL)
647 return -EINVAL;
648
649 /* Parse the transport specific mount options */
650 err = parse_opts(args, &opts);
651 if (err < 0)
652 return err;
653
654 /* Create and initialize the RDMA transport structure */
655 rdma = alloc_rdma(&opts);
656 if (!rdma)
657 return -ENOMEM;
658
659 /* Create the RDMA CM ID */
660 rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
661 RDMA_PS_TCP, IB_QPT_RC);
662 if (IS_ERR(rdma->cm_id))
663 goto error;
664
665 /* Associate the client with the transport */
666 client->trans = rdma;
667
668 /* Bind to a privileged port if we need to */
669 if (opts.privport) {
670 err = p9_rdma_bind_privport(rdma);
671 if (err < 0) {
672 pr_err("%s (%d): problem binding to privport: %d\n",
673 __func__, task_pid_nr(current), -err);
674 goto error;
675 }
676 }
677
678 /* Resolve the server's address */
679 rdma->addr.sin_family = AF_INET;
680 rdma->addr.sin_addr.s_addr = in_aton(addr);
681 rdma->addr.sin_port = htons(opts.port);
682 err = rdma_resolve_addr(rdma->cm_id, NULL,
683 (struct sockaddr *)&rdma->addr,
684 rdma->timeout);
685 if (err)
686 goto error;
687 err = wait_for_completion_interruptible(&rdma->cm_done);
688 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
689 goto error;
690
691 /* Resolve the route to the server */
692 err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
693 if (err)
694 goto error;
695 err = wait_for_completion_interruptible(&rdma->cm_done);
696 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
697 goto error;
698
699 /* Create the Completion Queue */
700 rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
701 opts.sq_depth + opts.rq_depth + 1,
702 IB_POLL_SOFTIRQ);
703 if (IS_ERR(rdma->cq))
704 goto error;
705
706 /* Create the Protection Domain */
707 rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
708 if (IS_ERR(rdma->pd))
709 goto error;
710
711 /* Create the Queue Pair */
712 memset(&qp_attr, 0, sizeof qp_attr);
713 qp_attr.event_handler = qp_event_handler;
714 qp_attr.qp_context = client;
715 qp_attr.cap.max_send_wr = opts.sq_depth;
716 qp_attr.cap.max_recv_wr = opts.rq_depth;
717 qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
718 qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
719 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
720 qp_attr.qp_type = IB_QPT_RC;
721 qp_attr.send_cq = rdma->cq;
722 qp_attr.recv_cq = rdma->cq;
723 err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
724 if (err)
725 goto error;
726 rdma->qp = rdma->cm_id->qp;
727
728 /* Request a connection */
729 memset(&conn_param, 0, sizeof(conn_param));
730 conn_param.private_data = NULL;
731 conn_param.private_data_len = 0;
732 conn_param.responder_resources = P9_RDMA_IRD;
733 conn_param.initiator_depth = P9_RDMA_ORD;
734 err = rdma_connect(rdma->cm_id, &conn_param);
735 if (err)
736 goto error;
737 err = wait_for_completion_interruptible(&rdma->cm_done);
738 if (err || (rdma->state != P9_RDMA_CONNECTED))
739 goto error;
740
741 client->status = Connected;
742
743 return 0;
744
745 error:
746 rdma_destroy_trans(rdma);
747 return -ENOTCONN;
748 }
749
750 static struct p9_trans_module p9_rdma_trans = {
751 .name = "rdma",
752 .maxsize = P9_RDMA_MAXSIZE,
753 .def = 0,
754 .owner = THIS_MODULE,
755 .create = rdma_create_trans,
756 .close = rdma_close,
757 .request = rdma_request,
758 .cancel = rdma_cancel,
759 .cancelled = rdma_cancelled,
760 .show_options = p9_rdma_show_options,
761 };
762
763 /**
764 * p9_trans_rdma_init - Register the 9P RDMA transport driver
765 */
p9_trans_rdma_init(void)766 static int __init p9_trans_rdma_init(void)
767 {
768 v9fs_register_trans(&p9_rdma_trans);
769 return 0;
770 }
771
p9_trans_rdma_exit(void)772 static void __exit p9_trans_rdma_exit(void)
773 {
774 v9fs_unregister_trans(&p9_rdma_trans);
775 }
776
777 module_init(p9_trans_rdma_init);
778 module_exit(p9_trans_rdma_exit);
779
780 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
781 MODULE_DESCRIPTION("RDMA Transport for 9P");
782 MODULE_LICENSE("Dual BSD/GPL");
783