blob: ba1210253f5ec077dc01fbd1e8fc6bf2102253ef [file] [log] [blame]
Tom Tuckerfc79d4b2008-10-22 18:47:39 -05001/*
2 * linux/fs/9p/trans_rdma.c
3 *
4 * RDMA transport layer based on the trans_fd.c implementation.
5 *
6 * Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
7 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
8 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
9 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
10 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2
14 * as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to:
23 * Free Software Foundation
24 * 51 Franklin Street, Fifth Floor
25 * Boston, MA 02111-1301 USA
26 *
27 */
28
Joe Perches5d385152011-11-28 10:40:46 -080029#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050031#include <linux/in.h>
32#include <linux/module.h>
33#include <linux/net.h>
34#include <linux/ipv6.h>
35#include <linux/kthread.h>
36#include <linux/errno.h>
37#include <linux/kernel.h>
38#include <linux/un.h>
39#include <linux/uaccess.h>
40#include <linux/inet.h>
41#include <linux/idr.h>
42#include <linux/file.h>
43#include <linux/parser.h>
44#include <linux/semaphore.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090045#include <linux/slab.h>
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050046#include <net/9p/9p.h>
47#include <net/9p/client.h>
48#include <net/9p/transport.h>
49#include <rdma/ib_verbs.h>
50#include <rdma/rdma_cm.h>
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050051
52#define P9_PORT 5640
53#define P9_RDMA_SQ_DEPTH 32
54#define P9_RDMA_RQ_DEPTH 32
55#define P9_RDMA_SEND_SGE 4
56#define P9_RDMA_RECV_SGE 4
57#define P9_RDMA_IRD 0
58#define P9_RDMA_ORD 0
59#define P9_RDMA_TIMEOUT 30000 /* 30 seconds */
Simon Derr3fcc62f2013-06-21 15:32:37 +020060#define P9_RDMA_MAXSIZE (1024*1024) /* 1MB */
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050061
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050062/**
63 * struct p9_trans_rdma - RDMA transport instance
64 *
65 * @state: tracks the transport state machine for connection setup and tear down
66 * @cm_id: The RDMA CM ID
67 * @pd: Protection Domain pointer
68 * @qp: Queue Pair pointer
69 * @cq: Completion Queue pointer
Abhishek Kulkarni0e155972009-07-19 13:41:55 -060070 * @dm_mr: DMA Memory Region pointer
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050071 * @lkey: The local access only memory region key
72 * @timeout: Number of uSecs to wait for connection management events
73 * @sq_depth: The depth of the Send Queue
74 * @sq_sem: Semaphore for the SQ
75 * @rq_depth: The depth of the Receive Queue.
Simon Derrfd453d02013-06-21 15:32:39 +020076 * @rq_sem: Semaphore for the RQ
Simon Derr1cff3302013-06-21 15:32:42 +020077 * @excess_rc : Amount of posted Receive Contexts without a pending request.
78 * See rdma_request()
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050079 * @addr: The remote peer's address
80 * @req_lock: Protects the active request list
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050081 * @cm_done: Completion event for connection management tracking
82 */
83struct p9_trans_rdma {
84 enum {
85 P9_RDMA_INIT,
86 P9_RDMA_ADDR_RESOLVED,
87 P9_RDMA_ROUTE_RESOLVED,
88 P9_RDMA_CONNECTED,
89 P9_RDMA_FLUSHING,
90 P9_RDMA_CLOSING,
91 P9_RDMA_CLOSED,
92 } state;
93 struct rdma_cm_id *cm_id;
94 struct ib_pd *pd;
95 struct ib_qp *qp;
96 struct ib_cq *cq;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -050097 long timeout;
98 int sq_depth;
99 struct semaphore sq_sem;
100 int rq_depth;
Simon Derrfd453d02013-06-21 15:32:39 +0200101 struct semaphore rq_sem;
Simon Derr1cff3302013-06-21 15:32:42 +0200102 atomic_t excess_rc;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500103 struct sockaddr_in addr;
104 spinlock_t req_lock;
105
106 struct completion cm_done;
107};
108
109/**
110 * p9_rdma_context - Keeps track of in-process WR
111 *
112 * @wc_op: The original WR op for when the CQE completes in error.
113 * @busa: Bus address to unmap when the WR completes
114 * @req: Keeps track of requests (send)
115 * @rc: Keepts track of replies (receive)
116 */
117struct p9_rdma_req;
118struct p9_rdma_context {
119 enum ib_wc_opcode wc_op;
120 dma_addr_t busa;
121 union {
122 struct p9_req_t *req;
123 struct p9_fcall *rc;
124 };
125};
126
127/**
128 * p9_rdma_opts - Collection of mount options
129 * @port: port of connection
130 * @sq_depth: The requested depth of the SQ. This really doesn't need
131 * to be any deeper than the number of threads used in the client
132 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
133 * @timeout: Time to wait in msecs for CM events
134 */
135struct p9_rdma_opts {
136 short port;
137 int sq_depth;
138 int rq_depth;
139 long timeout;
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100140 int privport;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500141};
142
143/*
144 * Option Parsing (code inspired by NFS code)
145 */
146enum {
147 /* Options that take integer arguments */
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100148 Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
149 /* Options that take no argument */
150 Opt_privport,
151 Opt_err,
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500152};
153
154static match_table_t tokens = {
155 {Opt_port, "port=%u"},
156 {Opt_sq_depth, "sq=%u"},
157 {Opt_rq_depth, "rq=%u"},
158 {Opt_timeout, "timeout=%u"},
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100159 {Opt_privport, "privport"},
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500160 {Opt_err, NULL},
161};
162
163/**
Abhishek Kulkarni0e155972009-07-19 13:41:55 -0600164 * parse_opts - parse mount options into rdma options structure
165 * @params: options string passed from mount
166 * @opts: rdma transport-specific structure to parse options into
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500167 *
168 * Returns 0 upon success, -ERRNO upon failure
169 */
170static int parse_opts(char *params, struct p9_rdma_opts *opts)
171{
172 char *p;
173 substring_t args[MAX_OPT_ARGS];
174 int option;
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600175 char *options, *tmp_options;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500176
177 opts->port = P9_PORT;
178 opts->sq_depth = P9_RDMA_SQ_DEPTH;
179 opts->rq_depth = P9_RDMA_RQ_DEPTH;
180 opts->timeout = P9_RDMA_TIMEOUT;
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100181 opts->privport = 0;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500182
183 if (!params)
184 return 0;
185
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600186 tmp_options = kstrdup(params, GFP_KERNEL);
187 if (!tmp_options) {
Joe Perches5d385152011-11-28 10:40:46 -0800188 p9_debug(P9_DEBUG_ERROR,
189 "failed to allocate copy of option string\n");
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500190 return -ENOMEM;
191 }
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600192 options = tmp_options;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500193
194 while ((p = strsep(&options, ",")) != NULL) {
195 int token;
196 int r;
197 if (!*p)
198 continue;
199 token = match_token(p, tokens, args);
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100200 if ((token != Opt_err) && (token != Opt_privport)) {
201 r = match_int(&args[0], &option);
202 if (r < 0) {
203 p9_debug(P9_DEBUG_ERROR,
204 "integer field, but no integer?\n");
205 continue;
206 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500207 }
208 switch (token) {
209 case Opt_port:
210 opts->port = option;
211 break;
212 case Opt_sq_depth:
213 opts->sq_depth = option;
214 break;
215 case Opt_rq_depth:
216 opts->rq_depth = option;
217 break;
218 case Opt_timeout:
219 opts->timeout = option;
220 break;
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100221 case Opt_privport:
222 opts->privport = 1;
223 break;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500224 default:
225 continue;
226 }
227 }
228 /* RQ must be at least as large as the SQ */
229 opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
Eric Van Hensbergend8c8a9e2010-02-08 16:23:23 -0600230 kfree(tmp_options);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500231 return 0;
232}
233
234static int
235p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
236{
237 struct p9_client *c = id->context;
238 struct p9_trans_rdma *rdma = c->trans;
239 switch (event->event) {
240 case RDMA_CM_EVENT_ADDR_RESOLVED:
241 BUG_ON(rdma->state != P9_RDMA_INIT);
242 rdma->state = P9_RDMA_ADDR_RESOLVED;
243 break;
244
245 case RDMA_CM_EVENT_ROUTE_RESOLVED:
246 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
247 rdma->state = P9_RDMA_ROUTE_RESOLVED;
248 break;
249
250 case RDMA_CM_EVENT_ESTABLISHED:
251 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
252 rdma->state = P9_RDMA_CONNECTED;
253 break;
254
255 case RDMA_CM_EVENT_DISCONNECTED:
256 if (rdma)
257 rdma->state = P9_RDMA_CLOSED;
258 if (c)
259 c->status = Disconnected;
260 break;
261
262 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
263 break;
264
265 case RDMA_CM_EVENT_ADDR_CHANGE:
266 case RDMA_CM_EVENT_ROUTE_ERROR:
267 case RDMA_CM_EVENT_DEVICE_REMOVAL:
268 case RDMA_CM_EVENT_MULTICAST_JOIN:
269 case RDMA_CM_EVENT_MULTICAST_ERROR:
270 case RDMA_CM_EVENT_REJECTED:
271 case RDMA_CM_EVENT_CONNECT_REQUEST:
272 case RDMA_CM_EVENT_CONNECT_RESPONSE:
273 case RDMA_CM_EVENT_CONNECT_ERROR:
274 case RDMA_CM_EVENT_ADDR_ERROR:
275 case RDMA_CM_EVENT_UNREACHABLE:
276 c->status = Disconnected;
277 rdma_disconnect(rdma->cm_id);
278 break;
279 default:
280 BUG();
281 }
282 complete(&rdma->cm_done);
283 return 0;
284}
285
286static void
287handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma,
288 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
289{
290 struct p9_req_t *req;
291 int err = 0;
292 int16_t tag;
293
294 req = NULL;
295 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
296 DMA_FROM_DEVICE);
297
298 if (status != IB_WC_SUCCESS)
299 goto err_out;
300
301 err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
302 if (err)
303 goto err_out;
304
305 req = p9_tag_lookup(client, tag);
306 if (!req)
307 goto err_out;
308
Simon Derr47229ff2013-06-21 15:32:38 +0200309 /* Check that we have not yet received a reply for this request.
310 */
311 if (unlikely(req->rc)) {
312 pr_err("Duplicate reply for request %d", tag);
313 goto err_out;
314 }
315
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500316 req->rc = c->rc;
Dominique Martinet2b6e72e2014-01-17 18:31:00 +0100317 p9_client_cb(client, req, REQ_STATUS_RCVD);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500318
319 return;
320
321 err_out:
Joe Perches5d385152011-11-28 10:40:46 -0800322 p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", req, err, status);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500323 rdma->state = P9_RDMA_FLUSHING;
324 client->status = Disconnected;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500325}
326
327static void
328handle_send(struct p9_client *client, struct p9_trans_rdma *rdma,
329 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len)
330{
331 ib_dma_unmap_single(rdma->cm_id->device,
332 c->busa, c->req->tc->size,
333 DMA_TO_DEVICE);
334}
335
336static void qp_event_handler(struct ib_event *event, void *context)
337{
Joe Perches5d385152011-11-28 10:40:46 -0800338 p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
339 event->event, context);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500340}
341
342static void cq_comp_handler(struct ib_cq *cq, void *cq_context)
343{
344 struct p9_client *client = cq_context;
345 struct p9_trans_rdma *rdma = client->trans;
346 int ret;
347 struct ib_wc wc;
348
349 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
350 while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) {
351 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id;
352
353 switch (c->wc_op) {
354 case IB_WC_RECV:
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500355 handle_recv(client, rdma, c, wc.status, wc.byte_len);
Simon Derrfd453d02013-06-21 15:32:39 +0200356 up(&rdma->rq_sem);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500357 break;
358
359 case IB_WC_SEND:
360 handle_send(client, rdma, c, wc.status, wc.byte_len);
361 up(&rdma->sq_sem);
362 break;
363
364 default:
Joe Perches5d385152011-11-28 10:40:46 -0800365 pr_err("unexpected completion type, c->wc_op=%d, wc.opcode=%d, status=%d\n",
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500366 c->wc_op, wc.opcode, wc.status);
367 break;
368 }
369 kfree(c);
370 }
371}
372
373static void cq_event_handler(struct ib_event *e, void *v)
374{
Joe Perches5d385152011-11-28 10:40:46 -0800375 p9_debug(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500376}
377
378static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
379{
380 if (!rdma)
381 return;
382
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500383 if (rdma->qp && !IS_ERR(rdma->qp))
384 ib_destroy_qp(rdma->qp);
385
386 if (rdma->pd && !IS_ERR(rdma->pd))
387 ib_dealloc_pd(rdma->pd);
388
389 if (rdma->cq && !IS_ERR(rdma->cq))
390 ib_destroy_cq(rdma->cq);
391
392 if (rdma->cm_id && !IS_ERR(rdma->cm_id))
393 rdma_destroy_id(rdma->cm_id);
394
395 kfree(rdma);
396}
397
398static int
399post_recv(struct p9_client *client, struct p9_rdma_context *c)
400{
401 struct p9_trans_rdma *rdma = client->trans;
402 struct ib_recv_wr wr, *bad_wr;
403 struct ib_sge sge;
404
405 c->busa = ib_dma_map_single(rdma->cm_id->device,
406 c->rc->sdata, client->msize,
407 DMA_FROM_DEVICE);
408 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
409 goto error;
410
411 sge.addr = c->busa;
412 sge.length = client->msize;
Jason Gunthorpe2f31fa82015-07-30 17:22:25 -0600413 sge.lkey = rdma->pd->local_dma_lkey;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500414
415 wr.next = NULL;
416 c->wc_op = IB_WC_RECV;
417 wr.wr_id = (unsigned long) c;
418 wr.sg_list = &sge;
419 wr.num_sge = 1;
420 return ib_post_recv(rdma->qp, &wr, &bad_wr);
421
422 error:
Joe Perches5d385152011-11-28 10:40:46 -0800423 p9_debug(P9_DEBUG_ERROR, "EIO\n");
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500424 return -EIO;
425}
426
427static int rdma_request(struct p9_client *client, struct p9_req_t *req)
428{
429 struct p9_trans_rdma *rdma = client->trans;
430 struct ib_send_wr wr, *bad_wr;
431 struct ib_sge sge;
432 int err = 0;
433 unsigned long flags;
434 struct p9_rdma_context *c = NULL;
435 struct p9_rdma_context *rpl_context = NULL;
436
Simon Derr1cff3302013-06-21 15:32:42 +0200437 /* When an error occurs between posting the recv and the send,
438 * there will be a receive context posted without a pending request.
439 * Since there is no way to "un-post" it, we remember it and skip
440 * post_recv() for the next request.
441 * So here,
442 * see if we are this `next request' and need to absorb an excess rc.
443 * If yes, then drop and free our own, and do not recv_post().
444 **/
445 if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
446 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
447 /* Got one ! */
448 kfree(req->rc);
449 req->rc = NULL;
450 goto dont_need_post_recv;
451 } else {
452 /* We raced and lost. */
453 atomic_inc(&rdma->excess_rc);
454 }
455 }
456
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500457 /* Allocate an fcall for the reply */
Aneesh Kumar K.Veeff66e2011-03-08 16:39:47 +0530458 rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000459 if (!rpl_context) {
460 err = -ENOMEM;
Simon Derr2f52d072013-06-21 15:32:41 +0200461 goto recv_error;
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000462 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500463 rpl_context->rc = req->rc;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500464
465 /*
466 * Post a receive buffer for this request. We need to ensure
467 * there is a reply buffer available for every outstanding
468 * request. A flushed request can result in no reply for an
469 * outstanding request, so we must keep a count to avoid
470 * overflowing the RQ.
471 */
Simon Derr2f52d072013-06-21 15:32:41 +0200472 if (down_interruptible(&rdma->rq_sem)) {
473 err = -EINTR;
474 goto recv_error;
475 }
Simon Derrfd453d02013-06-21 15:32:39 +0200476
477 err = post_recv(client, rpl_context);
478 if (err) {
479 p9_debug(P9_DEBUG_FCALL, "POST RECV failed\n");
Simon Derr2f52d072013-06-21 15:32:41 +0200480 goto recv_error;
Simon Derrfd453d02013-06-21 15:32:39 +0200481 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500482 /* remove posted receive buffer from request structure */
483 req->rc = NULL;
484
Simon Derr1cff3302013-06-21 15:32:42 +0200485dont_need_post_recv:
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500486 /* Post the request */
Aneesh Kumar K.Veeff66e2011-03-08 16:39:47 +0530487 c = kmalloc(sizeof *c, GFP_NOFS);
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000488 if (!c) {
489 err = -ENOMEM;
Simon Derr2f52d072013-06-21 15:32:41 +0200490 goto send_error;
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000491 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500492 c->req = req;
493
494 c->busa = ib_dma_map_single(rdma->cm_id->device,
495 c->req->tc->sdata, c->req->tc->size,
496 DMA_TO_DEVICE);
Simon Derr2f52d072013-06-21 15:32:41 +0200497 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
498 err = -EIO;
499 goto send_error;
500 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500501
502 sge.addr = c->busa;
503 sge.length = c->req->tc->size;
Jason Gunthorpe2f31fa82015-07-30 17:22:25 -0600504 sge.lkey = rdma->pd->local_dma_lkey;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500505
506 wr.next = NULL;
507 c->wc_op = IB_WC_SEND;
508 wr.wr_id = (unsigned long) c;
509 wr.opcode = IB_WR_SEND;
510 wr.send_flags = IB_SEND_SIGNALED;
511 wr.sg_list = &sge;
512 wr.num_sge = 1;
513
Simon Derr2f52d072013-06-21 15:32:41 +0200514 if (down_interruptible(&rdma->sq_sem)) {
515 err = -EINTR;
516 goto send_error;
517 }
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500518
Simon Derr3f9d5b82014-03-10 16:38:50 +0100519 /* Mark request as `sent' *before* we actually send it,
520 * because doing if after could erase the REQ_STATUS_RCVD
521 * status in case of a very fast reply.
522 */
523 req->status = REQ_STATUS_SENT;
Simon Derr2f52d072013-06-21 15:32:41 +0200524 err = ib_post_send(rdma->qp, &wr, &bad_wr);
525 if (err)
526 goto send_error;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500527
Simon Derr2f52d072013-06-21 15:32:41 +0200528 /* Success */
529 return 0;
530
531 /* Handle errors that happened during or while preparing the send: */
532 send_error:
Simon Derr3f9d5b82014-03-10 16:38:50 +0100533 req->status = REQ_STATUS_ERROR;
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000534 kfree(c);
Simon Derr2f52d072013-06-21 15:32:41 +0200535 p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
Simon Derr1cff3302013-06-21 15:32:42 +0200536
537 /* Ach.
538 * We did recv_post(), but not send. We have one recv_post in excess.
539 */
540 atomic_inc(&rdma->excess_rc);
Simon Derr2f52d072013-06-21 15:32:41 +0200541 return err;
542
543 /* Handle errors that happened during or while preparing post_recv(): */
544 recv_error:
Davidlohr Bueso1d6400c2010-09-13 15:53:18 +0000545 kfree(rpl_context);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500546 spin_lock_irqsave(&rdma->req_lock, flags);
547 if (rdma->state < P9_RDMA_CLOSING) {
548 rdma->state = P9_RDMA_CLOSING;
549 spin_unlock_irqrestore(&rdma->req_lock, flags);
550 rdma_disconnect(rdma->cm_id);
551 } else
552 spin_unlock_irqrestore(&rdma->req_lock, flags);
553 return err;
554}
555
556static void rdma_close(struct p9_client *client)
557{
558 struct p9_trans_rdma *rdma;
559
560 if (!client)
561 return;
562
563 rdma = client->trans;
564 if (!rdma)
565 return;
566
567 client->status = Disconnected;
568 rdma_disconnect(rdma->cm_id);
569 rdma_destroy_trans(rdma);
570}
571
572/**
573 * alloc_rdma - Allocate and initialize the rdma transport structure
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500574 * @opts: Mount options structure
575 */
576static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
577{
578 struct p9_trans_rdma *rdma;
579
580 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
581 if (!rdma)
582 return NULL;
583
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);
Simon Derrfd453d02013-06-21 15:32:39 +0200590 sema_init(&rdma->rq_sem, rdma->rq_depth);
Simon Derr1cff3302013-06-21 15:32:42 +0200591 atomic_set(&rdma->excess_rc, 0);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500592
593 return rdma;
594}
595
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500596static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
597{
Simon Derr931700d2014-03-10 16:38:51 +0100598 /* Nothing to do here.
599 * We will take care of it (if we have to) in rdma_cancelled()
600 */
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500601 return 1;
602}
603
Simon Derr931700d2014-03-10 16:38:51 +0100604/* A request has been fully flushed without a reply.
605 * That means we have posted one buffer in excess.
606 */
607static 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
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100614static 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
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500631/**
632 * trans_create_rdma - Transport method for creating atransport instance
633 * @client: client instance
634 * @addr: IP address string
635 * @args: Mount options string
636 */
637static int
638rdma_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;
Matan Barak8e372102015-06-11 16:35:21 +0300645 struct ib_cq_init_attr cq_attr = {};
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500646
647 /* Parse the transport specific mount options */
648 err = parse_opts(args, &opts);
649 if (err < 0)
650 return err;
651
652 /* Create and initialize the RDMA transport structure */
653 rdma = alloc_rdma(&opts);
654 if (!rdma)
655 return -ENOMEM;
656
657 /* Create the RDMA CM ID */
Sean Heftyb26f9b92010-04-01 17:08:41 +0000658 rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP,
659 IB_QPT_RC);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500660 if (IS_ERR(rdma->cm_id))
661 goto error;
662
Tom Tucker517ac452008-10-23 16:30:13 -0500663 /* Associate the client with the transport */
664 client->trans = rdma;
665
Dominique Martinetf569d3e2015-01-09 13:07:00 +0100666 /* Bind to a privileged port if we need to */
667 if (opts.privport) {
668 err = p9_rdma_bind_privport(rdma);
669 if (err < 0) {
670 pr_err("%s (%d): problem binding to privport: %d\n",
671 __func__, task_pid_nr(current), -err);
672 goto error;
673 }
674 }
675
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500676 /* Resolve the server's address */
677 rdma->addr.sin_family = AF_INET;
678 rdma->addr.sin_addr.s_addr = in_aton(addr);
679 rdma->addr.sin_port = htons(opts.port);
680 err = rdma_resolve_addr(rdma->cm_id, NULL,
681 (struct sockaddr *)&rdma->addr,
682 rdma->timeout);
683 if (err)
684 goto error;
685 err = wait_for_completion_interruptible(&rdma->cm_done);
686 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
687 goto error;
688
689 /* Resolve the route to the server */
690 err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
691 if (err)
692 goto error;
693 err = wait_for_completion_interruptible(&rdma->cm_done);
694 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
695 goto error;
696
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500697 /* Create the Completion Queue */
Matan Barak8e372102015-06-11 16:35:21 +0300698 cq_attr.cqe = opts.sq_depth + opts.rq_depth + 1;
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500699 rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler,
700 cq_event_handler, client,
Matan Barak8e372102015-06-11 16:35:21 +0300701 &cq_attr);
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500702 if (IS_ERR(rdma->cq))
703 goto error;
704 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP);
705
706 /* Create the Protection Domain */
707 rdma->pd = ib_alloc_pd(rdma->cm_id->device);
708 if (IS_ERR(rdma->pd))
709 goto error;
710
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500711 /* 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
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500741 client->status = Connected;
742
743 return 0;
744
745error:
746 rdma_destroy_trans(rdma);
747 return -ENOTCONN;
748}
749
750static 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,
Simon Derr931700d2014-03-10 16:38:51 +0100759 .cancelled = rdma_cancelled,
Tom Tuckerfc79d4b2008-10-22 18:47:39 -0500760};
761
762/**
763 * p9_trans_rdma_init - Register the 9P RDMA transport driver
764 */
765static int __init p9_trans_rdma_init(void)
766{
767 v9fs_register_trans(&p9_rdma_trans);
768 return 0;
769}
770
771static void __exit p9_trans_rdma_exit(void)
772{
773 v9fs_unregister_trans(&p9_rdma_trans);
774}
775
776module_init(p9_trans_rdma_init);
777module_exit(p9_trans_rdma_exit);
778
779MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
780MODULE_DESCRIPTION("RDMA Transport for 9P");
781MODULE_LICENSE("Dual BSD/GPL");