1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * RDMA Transport Layer
4 *
5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8 */
9
10 #undef pr_fmt
11 #define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
12
13 #include <linux/module.h>
14 #include <linux/rculist.h>
15 #include <linux/random.h>
16
17 #include "rtrs-clt.h"
18 #include "rtrs-log.h"
19 #include "rtrs-clt-trace.h"
20
21 #define RTRS_CONNECT_TIMEOUT_MS 30000
22 /*
23 * Wait a bit before trying to reconnect after a failure
24 * in order to give server time to finish clean up which
25 * leads to "false positives" failed reconnect attempts
26 */
27 #define RTRS_RECONNECT_BACKOFF 1000
28 /*
29 * Wait for additional random time between 0 and 8 seconds
30 * before starting to reconnect to avoid clients reconnecting
31 * all at once in case of a major network outage
32 */
33 #define RTRS_RECONNECT_SEED 8
34
35 #define FIRST_CONN 0x01
36 /* limit to 128 * 4k = 512k max IO */
37 #define RTRS_MAX_SEGMENTS 128
38
39 MODULE_DESCRIPTION("RDMA Transport Client");
40 MODULE_LICENSE("GPL");
41
42 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops;
43 static struct rtrs_rdma_dev_pd dev_pd = {
44 .ops = &dev_pd_ops
45 };
46
47 static struct workqueue_struct *rtrs_wq;
48 static const struct class rtrs_clt_dev_class = {
49 .name = "rtrs-client",
50 };
51
rtrs_clt_is_connected(const struct rtrs_clt_sess * clt)52 static inline bool rtrs_clt_is_connected(const struct rtrs_clt_sess *clt)
53 {
54 struct rtrs_clt_path *clt_path;
55 bool connected = false;
56
57 rcu_read_lock();
58 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry)
59 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED) {
60 connected = true;
61 break;
62 }
63 rcu_read_unlock();
64
65 return connected;
66 }
67
68 static struct rtrs_permit *
__rtrs_get_permit(struct rtrs_clt_sess * clt,enum rtrs_clt_con_type con_type)69 __rtrs_get_permit(struct rtrs_clt_sess *clt, enum rtrs_clt_con_type con_type)
70 {
71 size_t max_depth = clt->queue_depth;
72 struct rtrs_permit *permit;
73 int bit;
74
75 /*
76 * Adapted from null_blk get_tag(). Callers from different cpus may
77 * grab the same bit, since find_first_zero_bit is not atomic.
78 * But then the test_and_set_bit_lock will fail for all the
79 * callers but one, so that they will loop again.
80 * This way an explicit spinlock is not required.
81 */
82 do {
83 bit = find_first_zero_bit(clt->permits_map, max_depth);
84 if (bit >= max_depth)
85 return NULL;
86 } while (test_and_set_bit_lock(bit, clt->permits_map));
87
88 permit = get_permit(clt, bit);
89 WARN_ON(permit->mem_id != bit);
90 permit->cpu_id = raw_smp_processor_id();
91 permit->con_type = con_type;
92
93 return permit;
94 }
95
__rtrs_put_permit(struct rtrs_clt_sess * clt,struct rtrs_permit * permit)96 static inline void __rtrs_put_permit(struct rtrs_clt_sess *clt,
97 struct rtrs_permit *permit)
98 {
99 clear_bit_unlock(permit->mem_id, clt->permits_map);
100 }
101
102 /**
103 * rtrs_clt_get_permit() - allocates permit for future RDMA operation
104 * @clt: Current session
105 * @con_type: Type of connection to use with the permit
106 * @can_wait: Wait type
107 *
108 * Description:
109 * Allocates permit for the following RDMA operation. Permit is used
110 * to preallocate all resources and to propagate memory pressure
111 * up earlier.
112 *
113 * Context:
114 * Can sleep if @wait == RTRS_PERMIT_WAIT
115 */
rtrs_clt_get_permit(struct rtrs_clt_sess * clt,enum rtrs_clt_con_type con_type,enum wait_type can_wait)116 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *clt,
117 enum rtrs_clt_con_type con_type,
118 enum wait_type can_wait)
119 {
120 struct rtrs_permit *permit;
121 DEFINE_WAIT(wait);
122
123 permit = __rtrs_get_permit(clt, con_type);
124 if (permit || !can_wait)
125 return permit;
126
127 do {
128 prepare_to_wait(&clt->permits_wait, &wait,
129 TASK_UNINTERRUPTIBLE);
130 permit = __rtrs_get_permit(clt, con_type);
131 if (permit)
132 break;
133
134 io_schedule();
135 } while (1);
136
137 finish_wait(&clt->permits_wait, &wait);
138
139 return permit;
140 }
141 EXPORT_SYMBOL(rtrs_clt_get_permit);
142
143 /**
144 * rtrs_clt_put_permit() - puts allocated permit
145 * @clt: Current session
146 * @permit: Permit to be freed
147 *
148 * Context:
149 * Does not matter
150 */
rtrs_clt_put_permit(struct rtrs_clt_sess * clt,struct rtrs_permit * permit)151 void rtrs_clt_put_permit(struct rtrs_clt_sess *clt,
152 struct rtrs_permit *permit)
153 {
154 if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map)))
155 return;
156
157 __rtrs_put_permit(clt, permit);
158
159 /*
160 * rtrs_clt_get_permit() adds itself to the &clt->permits_wait list
161 * before calling schedule(). So if rtrs_clt_get_permit() is sleeping
162 * it must have added itself to &clt->permits_wait before
163 * __rtrs_put_permit() finished.
164 * Hence it is safe to guard wake_up() with a waitqueue_active() test.
165 */
166 if (waitqueue_active(&clt->permits_wait))
167 wake_up(&clt->permits_wait);
168 }
169 EXPORT_SYMBOL(rtrs_clt_put_permit);
170
171 /**
172 * rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit
173 * @clt_path: client path pointer
174 * @permit: permit for the allocation of the RDMA buffer
175 * Note:
176 * IO connection starts from 1.
177 * 0 connection is for user messages.
178 */
179 static
rtrs_permit_to_clt_con(struct rtrs_clt_path * clt_path,struct rtrs_permit * permit)180 struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_path *clt_path,
181 struct rtrs_permit *permit)
182 {
183 int id = 0;
184
185 if (permit->con_type == RTRS_IO_CON)
186 id = (permit->cpu_id % (clt_path->s.irq_con_num - 1)) + 1;
187
188 return to_clt_con(clt_path->s.con[id]);
189 }
190
191 /**
192 * rtrs_clt_change_state() - change the session state through session state
193 * machine.
194 *
195 * @clt_path: client path to change the state of.
196 * @new_state: state to change to.
197 *
198 * returns true if sess's state is changed to new state, otherwise return false.
199 *
200 * Locks:
201 * state_wq lock must be hold.
202 */
rtrs_clt_change_state(struct rtrs_clt_path * clt_path,enum rtrs_clt_state new_state)203 static bool rtrs_clt_change_state(struct rtrs_clt_path *clt_path,
204 enum rtrs_clt_state new_state)
205 {
206 enum rtrs_clt_state old_state;
207 bool changed = false;
208
209 lockdep_assert_held(&clt_path->state_wq.lock);
210
211 old_state = clt_path->state;
212 switch (new_state) {
213 case RTRS_CLT_CONNECTING:
214 switch (old_state) {
215 case RTRS_CLT_RECONNECTING:
216 changed = true;
217 fallthrough;
218 default:
219 break;
220 }
221 break;
222 case RTRS_CLT_RECONNECTING:
223 switch (old_state) {
224 case RTRS_CLT_CONNECTED:
225 case RTRS_CLT_CONNECTING_ERR:
226 case RTRS_CLT_CLOSED:
227 changed = true;
228 fallthrough;
229 default:
230 break;
231 }
232 break;
233 case RTRS_CLT_CONNECTED:
234 switch (old_state) {
235 case RTRS_CLT_CONNECTING:
236 changed = true;
237 fallthrough;
238 default:
239 break;
240 }
241 break;
242 case RTRS_CLT_CONNECTING_ERR:
243 switch (old_state) {
244 case RTRS_CLT_CONNECTING:
245 changed = true;
246 fallthrough;
247 default:
248 break;
249 }
250 break;
251 case RTRS_CLT_CLOSING:
252 switch (old_state) {
253 case RTRS_CLT_CONNECTING:
254 case RTRS_CLT_CONNECTING_ERR:
255 case RTRS_CLT_RECONNECTING:
256 case RTRS_CLT_CONNECTED:
257 changed = true;
258 fallthrough;
259 default:
260 break;
261 }
262 break;
263 case RTRS_CLT_CLOSED:
264 switch (old_state) {
265 case RTRS_CLT_CLOSING:
266 changed = true;
267 fallthrough;
268 default:
269 break;
270 }
271 break;
272 case RTRS_CLT_DEAD:
273 switch (old_state) {
274 case RTRS_CLT_CLOSED:
275 changed = true;
276 fallthrough;
277 default:
278 break;
279 }
280 break;
281 default:
282 break;
283 }
284 if (changed) {
285 clt_path->state = new_state;
286 wake_up_locked(&clt_path->state_wq);
287 }
288
289 return changed;
290 }
291
rtrs_clt_change_state_from_to(struct rtrs_clt_path * clt_path,enum rtrs_clt_state old_state,enum rtrs_clt_state new_state)292 static bool rtrs_clt_change_state_from_to(struct rtrs_clt_path *clt_path,
293 enum rtrs_clt_state old_state,
294 enum rtrs_clt_state new_state)
295 {
296 bool changed = false;
297
298 spin_lock_irq(&clt_path->state_wq.lock);
299 if (clt_path->state == old_state)
300 changed = rtrs_clt_change_state(clt_path, new_state);
301 spin_unlock_irq(&clt_path->state_wq.lock);
302
303 return changed;
304 }
305
306 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path);
rtrs_rdma_error_recovery(struct rtrs_clt_con * con)307 static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con)
308 {
309 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
310
311 trace_rtrs_rdma_error_recovery(clt_path);
312
313 if (rtrs_clt_change_state_from_to(clt_path,
314 RTRS_CLT_CONNECTED,
315 RTRS_CLT_RECONNECTING)) {
316 queue_work(rtrs_wq, &clt_path->err_recovery_work);
317 } else {
318 /*
319 * Error can happen just on establishing new connection,
320 * so notify waiter with error state, waiter is responsible
321 * for cleaning the rest and reconnect if needed.
322 */
323 rtrs_clt_change_state_from_to(clt_path,
324 RTRS_CLT_CONNECTING,
325 RTRS_CLT_CONNECTING_ERR);
326 }
327 }
328
rtrs_clt_fast_reg_done(struct ib_cq * cq,struct ib_wc * wc)329 static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc)
330 {
331 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
332
333 if (wc->status != IB_WC_SUCCESS) {
334 rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n",
335 ib_wc_status_msg(wc->status));
336 rtrs_rdma_error_recovery(con);
337 }
338 }
339
340 static struct ib_cqe fast_reg_cqe = {
341 .done = rtrs_clt_fast_reg_done
342 };
343
344 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
345 bool notify, bool can_wait);
346
rtrs_clt_inv_rkey_done(struct ib_cq * cq,struct ib_wc * wc)347 static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
348 {
349 struct rtrs_clt_io_req *req =
350 container_of(wc->wr_cqe, typeof(*req), inv_cqe);
351 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
352
353 if (wc->status != IB_WC_SUCCESS) {
354 rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n",
355 ib_wc_status_msg(wc->status));
356 rtrs_rdma_error_recovery(con);
357 }
358 req->need_inv = false;
359 if (req->need_inv_comp)
360 complete(&req->inv_comp);
361 else
362 /* Complete request from INV callback */
363 complete_rdma_req(req, req->inv_errno, true, false);
364 }
365
rtrs_inv_rkey(struct rtrs_clt_io_req * req)366 static int rtrs_inv_rkey(struct rtrs_clt_io_req *req)
367 {
368 struct rtrs_clt_con *con = req->con;
369 struct ib_send_wr wr = {
370 .opcode = IB_WR_LOCAL_INV,
371 .wr_cqe = &req->inv_cqe,
372 .send_flags = IB_SEND_SIGNALED,
373 .ex.invalidate_rkey = req->mr->rkey,
374 };
375 req->inv_cqe.done = rtrs_clt_inv_rkey_done;
376
377 return ib_post_send(con->c.qp, &wr, NULL);
378 }
379
complete_rdma_req(struct rtrs_clt_io_req * req,int errno,bool notify,bool can_wait)380 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
381 bool notify, bool can_wait)
382 {
383 struct rtrs_clt_con *con = req->con;
384 struct rtrs_clt_path *clt_path;
385 int err;
386
387 if (WARN_ON(!req->in_use))
388 return;
389 if (WARN_ON(!req->con))
390 return;
391 clt_path = to_clt_path(con->c.path);
392
393 if (req->sg_cnt) {
394 if (req->dir == DMA_FROM_DEVICE && req->need_inv) {
395 /*
396 * We are here to invalidate read requests
397 * ourselves. In normal scenario server should
398 * send INV for all read requests, but
399 * we are here, thus two things could happen:
400 *
401 * 1. this is failover, when errno != 0
402 * and can_wait == 1,
403 *
404 * 2. something totally bad happened and
405 * server forgot to send INV, so we
406 * should do that ourselves.
407 */
408
409 if (can_wait) {
410 req->need_inv_comp = true;
411 } else {
412 /* This should be IO path, so always notify */
413 WARN_ON(!notify);
414 /* Save errno for INV callback */
415 req->inv_errno = errno;
416 }
417
418 refcount_inc(&req->ref);
419 err = rtrs_inv_rkey(req);
420 if (err) {
421 rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n",
422 req->mr->rkey, err);
423 } else if (can_wait) {
424 wait_for_completion(&req->inv_comp);
425 } else {
426 /*
427 * Something went wrong, so request will be
428 * completed from INV callback.
429 */
430 WARN_ON_ONCE(1);
431
432 return;
433 }
434 if (!refcount_dec_and_test(&req->ref))
435 return;
436 }
437 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
438 req->sg_cnt, req->dir);
439 }
440 if (!refcount_dec_and_test(&req->ref))
441 return;
442 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
443 atomic_dec(&clt_path->stats->inflight);
444
445 req->in_use = false;
446 req->con = NULL;
447
448 if (errno) {
449 rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n",
450 errno, kobject_name(&clt_path->kobj), clt_path->hca_name,
451 clt_path->hca_port, notify);
452 }
453
454 if (notify)
455 req->conf(req->priv, errno);
456 }
457
rtrs_post_send_rdma(struct rtrs_clt_con * con,struct rtrs_clt_io_req * req,struct rtrs_rbuf * rbuf,u32 off,u32 imm,struct ib_send_wr * wr)458 static int rtrs_post_send_rdma(struct rtrs_clt_con *con,
459 struct rtrs_clt_io_req *req,
460 struct rtrs_rbuf *rbuf, u32 off,
461 u32 imm, struct ib_send_wr *wr)
462 {
463 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
464 enum ib_send_flags flags;
465 struct ib_sge sge;
466
467 if (!req->sg_size) {
468 rtrs_wrn(con->c.path,
469 "Doing RDMA Write failed, no data supplied\n");
470 return -EINVAL;
471 }
472
473 /* user data and user message in the first list element */
474 sge.addr = req->iu->dma_addr;
475 sge.length = req->sg_size;
476 sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
477
478 /*
479 * From time to time we have to post signalled sends,
480 * or send queue will fill up and only QP reset can help.
481 */
482 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
483 0 : IB_SEND_SIGNALED;
484
485 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
486 req->iu->dma_addr,
487 req->sg_size, DMA_TO_DEVICE);
488
489 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1,
490 rbuf->rkey, rbuf->addr + off,
491 imm, flags, wr, NULL);
492 }
493
process_io_rsp(struct rtrs_clt_path * clt_path,u32 msg_id,s16 errno,bool w_inval)494 static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id,
495 s16 errno, bool w_inval)
496 {
497 struct rtrs_clt_io_req *req;
498
499 if (WARN_ON(msg_id >= clt_path->queue_depth))
500 return;
501
502 req = &clt_path->reqs[msg_id];
503 /* Drop need_inv if server responded with send with invalidation */
504 req->need_inv &= !w_inval;
505 complete_rdma_req(req, errno, true, false);
506 }
507
rtrs_clt_recv_done(struct rtrs_clt_con * con,struct ib_wc * wc)508 static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc)
509 {
510 struct rtrs_iu *iu;
511 int err;
512 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
513
514 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0);
515 iu = container_of(wc->wr_cqe, struct rtrs_iu,
516 cqe);
517 err = rtrs_iu_post_recv(&con->c, iu);
518 if (err) {
519 rtrs_err(con->c.path, "post iu failed %d\n", err);
520 rtrs_rdma_error_recovery(con);
521 }
522 }
523
rtrs_clt_rkey_rsp_done(struct rtrs_clt_con * con,struct ib_wc * wc)524 static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc)
525 {
526 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
527 struct rtrs_msg_rkey_rsp *msg;
528 u32 imm_type, imm_payload;
529 bool w_inval = false;
530 struct rtrs_iu *iu;
531 u32 buf_id;
532 int err;
533
534 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0);
535
536 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
537
538 if (wc->byte_len < sizeof(*msg)) {
539 rtrs_err(con->c.path, "rkey response is malformed: size %d\n",
540 wc->byte_len);
541 goto out;
542 }
543 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
544 iu->size, DMA_FROM_DEVICE);
545 msg = iu->buf;
546 if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) {
547 rtrs_err(clt_path->clt,
548 "rkey response is malformed: type %d\n",
549 le16_to_cpu(msg->type));
550 goto out;
551 }
552 buf_id = le16_to_cpu(msg->buf_id);
553 if (WARN_ON(buf_id >= clt_path->queue_depth))
554 goto out;
555
556 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload);
557 if (imm_type == RTRS_IO_RSP_IMM ||
558 imm_type == RTRS_IO_RSP_W_INV_IMM) {
559 u32 msg_id;
560
561 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
562 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
563
564 if (WARN_ON(buf_id != msg_id))
565 goto out;
566 clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey);
567 process_io_rsp(clt_path, msg_id, err, w_inval);
568 }
569 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr,
570 iu->size, DMA_FROM_DEVICE);
571 return rtrs_clt_recv_done(con, wc);
572 out:
573 rtrs_rdma_error_recovery(con);
574 }
575
576 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
577
578 static struct ib_cqe io_comp_cqe = {
579 .done = rtrs_clt_rdma_done
580 };
581
582 /*
583 * Post x2 empty WRs: first is for this RDMA with IMM,
584 * second is for RECV with INV, which happened earlier.
585 */
rtrs_post_recv_empty_x2(struct rtrs_con * con,struct ib_cqe * cqe)586 static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe)
587 {
588 struct ib_recv_wr wr_arr[2], *wr;
589 int i;
590
591 memset(wr_arr, 0, sizeof(wr_arr));
592 for (i = 0; i < ARRAY_SIZE(wr_arr); i++) {
593 wr = &wr_arr[i];
594 wr->wr_cqe = cqe;
595 if (i)
596 /* Chain backwards */
597 wr->next = &wr_arr[i - 1];
598 }
599
600 return ib_post_recv(con->qp, wr, NULL);
601 }
602
rtrs_clt_rdma_done(struct ib_cq * cq,struct ib_wc * wc)603 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
604 {
605 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
606 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
607 u32 imm_type, imm_payload;
608 bool w_inval = false;
609 int err;
610
611 if (wc->status != IB_WC_SUCCESS) {
612 if (wc->status != IB_WC_WR_FLUSH_ERR) {
613 rtrs_err(clt_path->clt, "RDMA failed: %s\n",
614 ib_wc_status_msg(wc->status));
615 rtrs_rdma_error_recovery(con);
616 }
617 return;
618 }
619 rtrs_clt_update_wc_stats(con);
620
621 switch (wc->opcode) {
622 case IB_WC_RECV_RDMA_WITH_IMM:
623 /*
624 * post_recv() RDMA write completions of IO reqs (read/write)
625 * and hb
626 */
627 if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done))
628 return;
629 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
630 &imm_type, &imm_payload);
631 if (imm_type == RTRS_IO_RSP_IMM ||
632 imm_type == RTRS_IO_RSP_W_INV_IMM) {
633 u32 msg_id;
634
635 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
636 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
637
638 process_io_rsp(clt_path, msg_id, err, w_inval);
639 } else if (imm_type == RTRS_HB_MSG_IMM) {
640 WARN_ON(con->c.cid);
641 rtrs_send_hb_ack(&clt_path->s);
642 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
643 return rtrs_clt_recv_done(con, wc);
644 } else if (imm_type == RTRS_HB_ACK_IMM) {
645 WARN_ON(con->c.cid);
646 clt_path->s.hb_missed_cnt = 0;
647 clt_path->s.hb_cur_latency =
648 ktime_sub(ktime_get(), clt_path->s.hb_last_sent);
649 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
650 return rtrs_clt_recv_done(con, wc);
651 } else {
652 rtrs_wrn(con->c.path, "Unknown IMM type %u\n",
653 imm_type);
654 }
655 if (w_inval)
656 /*
657 * Post x2 empty WRs: first is for this RDMA with IMM,
658 * second is for RECV with INV, which happened earlier.
659 */
660 err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe);
661 else
662 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
663 if (err) {
664 rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n",
665 err);
666 rtrs_rdma_error_recovery(con);
667 }
668 break;
669 case IB_WC_RECV:
670 /*
671 * Key invalidations from server side
672 */
673 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE ||
674 wc->wc_flags & IB_WC_WITH_IMM));
675 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done);
676 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
677 if (wc->wc_flags & IB_WC_WITH_INVALIDATE)
678 return rtrs_clt_recv_done(con, wc);
679
680 return rtrs_clt_rkey_rsp_done(con, wc);
681 }
682 break;
683 case IB_WC_RDMA_WRITE:
684 /*
685 * post_send() RDMA write completions of IO reqs (read/write)
686 * and hb.
687 */
688 break;
689
690 default:
691 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode);
692 return;
693 }
694 }
695
post_recv_io(struct rtrs_clt_con * con,size_t q_size)696 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size)
697 {
698 int err, i;
699 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
700
701 for (i = 0; i < q_size; i++) {
702 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
703 struct rtrs_iu *iu = &con->rsp_ius[i];
704
705 err = rtrs_iu_post_recv(&con->c, iu);
706 } else {
707 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
708 }
709 if (err)
710 return err;
711 }
712
713 return 0;
714 }
715
post_recv_path(struct rtrs_clt_path * clt_path)716 static int post_recv_path(struct rtrs_clt_path *clt_path)
717 {
718 size_t q_size = 0;
719 int err, cid;
720
721 for (cid = 0; cid < clt_path->s.con_num; cid++) {
722 if (cid == 0)
723 q_size = SERVICE_CON_QUEUE_DEPTH;
724 else
725 q_size = clt_path->queue_depth;
726
727 /*
728 * x2 for RDMA read responses + FR key invalidations,
729 * RDMA writes do not require any FR registrations.
730 */
731 q_size *= 2;
732
733 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size);
734 if (err) {
735 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n",
736 err);
737 return err;
738 }
739 }
740
741 return 0;
742 }
743
744 struct path_it {
745 int i;
746 struct list_head skip_list;
747 struct rtrs_clt_sess *clt;
748 struct rtrs_clt_path *(*next_path)(struct path_it *it);
749 };
750
751 /*
752 * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL
753 * @head: the head for the list.
754 * @clt_path: The element to take the next clt_path from.
755 *
756 * Next clt path returned in round-robin fashion, i.e. head will be skipped,
757 * but if list is observed as empty, NULL will be returned.
758 *
759 * This function may safely run concurrently with the _rcu list-mutation
760 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
761 */
762 static inline struct rtrs_clt_path *
rtrs_clt_get_next_path_or_null(struct list_head * head,struct rtrs_clt_path * clt_path)763 rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path)
764 {
765 return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?:
766 list_next_or_null_rcu(head,
767 READ_ONCE((&clt_path->s.entry)->next),
768 typeof(*clt_path), s.entry);
769 }
770
771 /**
772 * get_next_path_rr() - Returns path in round-robin fashion.
773 * @it: the path pointer
774 *
775 * Related to @MP_POLICY_RR
776 *
777 * Locks:
778 * rcu_read_lock() must be hold.
779 */
get_next_path_rr(struct path_it * it)780 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it)
781 {
782 struct rtrs_clt_path __rcu **ppcpu_path;
783 struct rtrs_clt_path *path;
784 struct rtrs_clt_sess *clt;
785
786 clt = it->clt;
787
788 /*
789 * Here we use two RCU objects: @paths_list and @pcpu_path
790 * pointer. See rtrs_clt_remove_path_from_arr() for details
791 * how that is handled.
792 */
793
794 ppcpu_path = this_cpu_ptr(clt->pcpu_path);
795 path = rcu_dereference(*ppcpu_path);
796 if (!path)
797 path = list_first_or_null_rcu(&clt->paths_list,
798 typeof(*path), s.entry);
799 else
800 path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path);
801
802 rcu_assign_pointer(*ppcpu_path, path);
803
804 return path;
805 }
806
807 /**
808 * get_next_path_min_inflight() - Returns path with minimal inflight count.
809 * @it: the path pointer
810 *
811 * Related to @MP_POLICY_MIN_INFLIGHT
812 *
813 * Locks:
814 * rcu_read_lock() must be hold.
815 */
get_next_path_min_inflight(struct path_it * it)816 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it)
817 {
818 struct rtrs_clt_path *min_path = NULL;
819 struct rtrs_clt_sess *clt = it->clt;
820 struct rtrs_clt_path *clt_path;
821 int min_inflight = INT_MAX;
822 int inflight;
823
824 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
825 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
826 continue;
827
828 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
829 continue;
830
831 inflight = atomic_read(&clt_path->stats->inflight);
832
833 if (inflight < min_inflight) {
834 min_inflight = inflight;
835 min_path = clt_path;
836 }
837 }
838
839 /*
840 * add the path to the skip list, so that next time we can get
841 * a different one
842 */
843 if (min_path)
844 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
845
846 return min_path;
847 }
848
849 /**
850 * get_next_path_min_latency() - Returns path with minimal latency.
851 * @it: the path pointer
852 *
853 * Return: a path with the lowest latency or NULL if all paths are tried
854 *
855 * Locks:
856 * rcu_read_lock() must be hold.
857 *
858 * Related to @MP_POLICY_MIN_LATENCY
859 *
860 * This DOES skip an already-tried path.
861 * There is a skip-list to skip a path if the path has tried but failed.
862 * It will try the minimum latency path and then the second minimum latency
863 * path and so on. Finally it will return NULL if all paths are tried.
864 * Therefore the caller MUST check the returned
865 * path is NULL and trigger the IO error.
866 */
get_next_path_min_latency(struct path_it * it)867 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it)
868 {
869 struct rtrs_clt_path *min_path = NULL;
870 struct rtrs_clt_sess *clt = it->clt;
871 struct rtrs_clt_path *clt_path;
872 ktime_t min_latency = KTIME_MAX;
873 ktime_t latency;
874
875 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
876 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
877 continue;
878
879 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
880 continue;
881
882 latency = clt_path->s.hb_cur_latency;
883
884 if (latency < min_latency) {
885 min_latency = latency;
886 min_path = clt_path;
887 }
888 }
889
890 /*
891 * add the path to the skip list, so that next time we can get
892 * a different one
893 */
894 if (min_path)
895 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
896
897 return min_path;
898 }
899
path_it_init(struct path_it * it,struct rtrs_clt_sess * clt)900 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt)
901 {
902 INIT_LIST_HEAD(&it->skip_list);
903 it->clt = clt;
904 it->i = 0;
905
906 if (clt->mp_policy == MP_POLICY_RR)
907 it->next_path = get_next_path_rr;
908 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
909 it->next_path = get_next_path_min_inflight;
910 else
911 it->next_path = get_next_path_min_latency;
912 }
913
path_it_deinit(struct path_it * it)914 static inline void path_it_deinit(struct path_it *it)
915 {
916 struct list_head *skip, *tmp;
917 /*
918 * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies.
919 * We need to remove paths from it, so that next IO can insert
920 * paths (->mp_skip_entry) into a skip_list again.
921 */
922 list_for_each_safe(skip, tmp, &it->skip_list)
923 list_del_init(skip);
924 }
925
926 /**
927 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information
928 * about an inflight IO.
929 * The user buffer holding user control message (not data) is copied into
930 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will
931 * also hold the control message of rtrs.
932 * @req: an io request holding information about IO.
933 * @clt_path: client path
934 * @conf: conformation callback function to notify upper layer.
935 * @permit: permit for allocation of RDMA remote buffer
936 * @priv: private pointer
937 * @vec: kernel vector containing control message
938 * @usr_len: length of the user message
939 * @sg: scater list for IO data
940 * @sg_cnt: number of scater list entries
941 * @data_len: length of the IO data
942 * @dir: direction of the IO.
943 */
rtrs_clt_init_req(struct rtrs_clt_io_req * req,struct rtrs_clt_path * clt_path,void (* conf)(void * priv,int errno),struct rtrs_permit * permit,void * priv,const struct kvec * vec,size_t usr_len,struct scatterlist * sg,size_t sg_cnt,size_t data_len,int dir)944 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
945 struct rtrs_clt_path *clt_path,
946 void (*conf)(void *priv, int errno),
947 struct rtrs_permit *permit, void *priv,
948 const struct kvec *vec, size_t usr_len,
949 struct scatterlist *sg, size_t sg_cnt,
950 size_t data_len, int dir)
951 {
952 struct iov_iter iter;
953 size_t len;
954
955 req->permit = permit;
956 req->in_use = true;
957 req->usr_len = usr_len;
958 req->data_len = data_len;
959 req->sglist = sg;
960 req->sg_cnt = sg_cnt;
961 req->priv = priv;
962 req->dir = dir;
963 req->con = rtrs_permit_to_clt_con(clt_path, permit);
964 req->conf = conf;
965 req->need_inv = false;
966 req->need_inv_comp = false;
967 req->inv_errno = 0;
968 refcount_set(&req->ref, 1);
969 req->mp_policy = clt_path->clt->mp_policy;
970
971 iov_iter_kvec(&iter, ITER_SOURCE, vec, 1, usr_len);
972 len = _copy_from_iter(req->iu->buf, usr_len, &iter);
973 WARN_ON(len != usr_len);
974
975 reinit_completion(&req->inv_comp);
976 }
977
978 static struct rtrs_clt_io_req *
rtrs_clt_get_req(struct rtrs_clt_path * clt_path,void (* conf)(void * priv,int errno),struct rtrs_permit * permit,void * priv,const struct kvec * vec,size_t usr_len,struct scatterlist * sg,size_t sg_cnt,size_t data_len,int dir)979 rtrs_clt_get_req(struct rtrs_clt_path *clt_path,
980 void (*conf)(void *priv, int errno),
981 struct rtrs_permit *permit, void *priv,
982 const struct kvec *vec, size_t usr_len,
983 struct scatterlist *sg, size_t sg_cnt,
984 size_t data_len, int dir)
985 {
986 struct rtrs_clt_io_req *req;
987
988 req = &clt_path->reqs[permit->mem_id];
989 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len,
990 sg, sg_cnt, data_len, dir);
991 return req;
992 }
993
994 static struct rtrs_clt_io_req *
rtrs_clt_get_copy_req(struct rtrs_clt_path * alive_path,struct rtrs_clt_io_req * fail_req)995 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path,
996 struct rtrs_clt_io_req *fail_req)
997 {
998 struct rtrs_clt_io_req *req;
999 struct kvec vec = {
1000 .iov_base = fail_req->iu->buf,
1001 .iov_len = fail_req->usr_len
1002 };
1003
1004 req = &alive_path->reqs[fail_req->permit->mem_id];
1005 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit,
1006 fail_req->priv, &vec, fail_req->usr_len,
1007 fail_req->sglist, fail_req->sg_cnt,
1008 fail_req->data_len, fail_req->dir);
1009 return req;
1010 }
1011
rtrs_post_rdma_write_sg(struct rtrs_clt_con * con,struct rtrs_clt_io_req * req,struct rtrs_rbuf * rbuf,bool fr_en,u32 count,u32 size,u32 imm,struct ib_send_wr * wr,struct ib_send_wr * tail)1012 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
1013 struct rtrs_clt_io_req *req,
1014 struct rtrs_rbuf *rbuf, bool fr_en,
1015 u32 count, u32 size, u32 imm,
1016 struct ib_send_wr *wr,
1017 struct ib_send_wr *tail)
1018 {
1019 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1020 struct ib_sge *sge = req->sge;
1021 enum ib_send_flags flags;
1022 struct scatterlist *sg;
1023 size_t num_sge;
1024 int i;
1025 struct ib_send_wr *ptail = NULL;
1026
1027 if (fr_en) {
1028 i = 0;
1029 sge[i].addr = req->mr->iova;
1030 sge[i].length = req->mr->length;
1031 sge[i].lkey = req->mr->lkey;
1032 i++;
1033 num_sge = 2;
1034 ptail = tail;
1035 } else {
1036 for_each_sg(req->sglist, sg, count, i) {
1037 sge[i].addr = sg_dma_address(sg);
1038 sge[i].length = sg_dma_len(sg);
1039 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
1040 }
1041 num_sge = 1 + count;
1042 }
1043 sge[i].addr = req->iu->dma_addr;
1044 sge[i].length = size;
1045 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
1046
1047 /*
1048 * From time to time we have to post signalled sends,
1049 * or send queue will fill up and only QP reset can help.
1050 */
1051 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
1052 0 : IB_SEND_SIGNALED;
1053
1054 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
1055 req->iu->dma_addr,
1056 size, DMA_TO_DEVICE);
1057
1058 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
1059 rbuf->rkey, rbuf->addr, imm,
1060 flags, wr, ptail);
1061 }
1062
rtrs_map_sg_fr(struct rtrs_clt_io_req * req,size_t count)1063 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
1064 {
1065 int nr;
1066
1067 /* Align the MR to a 4K page size to match the block virt boundary */
1068 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
1069 if (nr != count)
1070 return nr < 0 ? nr : -EINVAL;
1071 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
1072
1073 return nr;
1074 }
1075
rtrs_clt_write_req(struct rtrs_clt_io_req * req)1076 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
1077 {
1078 struct rtrs_clt_con *con = req->con;
1079 struct rtrs_path *s = con->c.path;
1080 struct rtrs_clt_path *clt_path = to_clt_path(s);
1081 struct rtrs_msg_rdma_write *msg;
1082
1083 struct rtrs_rbuf *rbuf;
1084 int ret, count = 0;
1085 u32 imm, buf_id;
1086 struct ib_reg_wr rwr;
1087 struct ib_send_wr inv_wr;
1088 struct ib_send_wr *wr = NULL;
1089 bool fr_en = false;
1090
1091 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
1092
1093 if (tsize > clt_path->chunk_size) {
1094 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n",
1095 tsize, clt_path->chunk_size);
1096 return -EMSGSIZE;
1097 }
1098 if (req->sg_cnt) {
1099 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist,
1100 req->sg_cnt, req->dir);
1101 if (!count) {
1102 rtrs_wrn(s, "Write request failed, map failed\n");
1103 return -EINVAL;
1104 }
1105 }
1106 /* put rtrs msg after sg and user message */
1107 msg = req->iu->buf + req->usr_len;
1108 msg->type = cpu_to_le16(RTRS_MSG_WRITE);
1109 msg->usr_len = cpu_to_le16(req->usr_len);
1110
1111 /* rtrs message on server side will be after user data and message */
1112 imm = req->permit->mem_off + req->data_len + req->usr_len;
1113 imm = rtrs_to_io_req_imm(imm);
1114 buf_id = req->permit->mem_id;
1115 req->sg_size = tsize;
1116 rbuf = &clt_path->rbufs[buf_id];
1117
1118 if (count) {
1119 ret = rtrs_map_sg_fr(req, count);
1120 if (ret < 0) {
1121 rtrs_err_rl(s,
1122 "Write request failed, failed to map fast reg. data, err: %d\n",
1123 ret);
1124 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
1125 req->sg_cnt, req->dir);
1126 return ret;
1127 }
1128 inv_wr = (struct ib_send_wr) {
1129 .opcode = IB_WR_LOCAL_INV,
1130 .wr_cqe = &req->inv_cqe,
1131 .send_flags = IB_SEND_SIGNALED,
1132 .ex.invalidate_rkey = req->mr->rkey,
1133 };
1134 req->inv_cqe.done = rtrs_clt_inv_rkey_done;
1135 rwr = (struct ib_reg_wr) {
1136 .wr.opcode = IB_WR_REG_MR,
1137 .wr.wr_cqe = &fast_reg_cqe,
1138 .mr = req->mr,
1139 .key = req->mr->rkey,
1140 .access = (IB_ACCESS_LOCAL_WRITE),
1141 };
1142 wr = &rwr.wr;
1143 fr_en = true;
1144 refcount_inc(&req->ref);
1145 }
1146 /*
1147 * Update stats now, after request is successfully sent it is not
1148 * safe anymore to touch it.
1149 */
1150 rtrs_clt_update_all_stats(req, WRITE);
1151
1152 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count,
1153 req->usr_len + sizeof(*msg),
1154 imm, wr, &inv_wr);
1155 if (ret) {
1156 rtrs_err_rl(s,
1157 "Write request failed: error=%d path=%s [%s:%u]\n",
1158 ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
1159 clt_path->hca_port);
1160 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
1161 atomic_dec(&clt_path->stats->inflight);
1162 if (req->sg_cnt)
1163 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
1164 req->sg_cnt, req->dir);
1165 }
1166
1167 return ret;
1168 }
1169
rtrs_clt_read_req(struct rtrs_clt_io_req * req)1170 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req)
1171 {
1172 struct rtrs_clt_con *con = req->con;
1173 struct rtrs_path *s = con->c.path;
1174 struct rtrs_clt_path *clt_path = to_clt_path(s);
1175 struct rtrs_msg_rdma_read *msg;
1176 struct rtrs_ib_dev *dev = clt_path->s.dev;
1177
1178 struct ib_reg_wr rwr;
1179 struct ib_send_wr *wr = NULL;
1180
1181 int ret, count = 0;
1182 u32 imm, buf_id;
1183
1184 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
1185
1186 if (tsize > clt_path->chunk_size) {
1187 rtrs_wrn(s,
1188 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n",
1189 tsize, clt_path->chunk_size);
1190 return -EMSGSIZE;
1191 }
1192
1193 if (req->sg_cnt) {
1194 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt,
1195 req->dir);
1196 if (!count) {
1197 rtrs_wrn(s,
1198 "Read request failed, dma map failed\n");
1199 return -EINVAL;
1200 }
1201 }
1202 /* put our message into req->buf after user message*/
1203 msg = req->iu->buf + req->usr_len;
1204 msg->type = cpu_to_le16(RTRS_MSG_READ);
1205 msg->usr_len = cpu_to_le16(req->usr_len);
1206
1207 if (count) {
1208 ret = rtrs_map_sg_fr(req, count);
1209 if (ret < 0) {
1210 rtrs_err_rl(s,
1211 "Read request failed, failed to map fast reg. data, err: %d\n",
1212 ret);
1213 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt,
1214 req->dir);
1215 return ret;
1216 }
1217 rwr = (struct ib_reg_wr) {
1218 .wr.opcode = IB_WR_REG_MR,
1219 .wr.wr_cqe = &fast_reg_cqe,
1220 .mr = req->mr,
1221 .key = req->mr->rkey,
1222 .access = (IB_ACCESS_LOCAL_WRITE |
1223 IB_ACCESS_REMOTE_WRITE),
1224 };
1225 wr = &rwr.wr;
1226
1227 msg->sg_cnt = cpu_to_le16(1);
1228 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F);
1229
1230 msg->desc[0].addr = cpu_to_le64(req->mr->iova);
1231 msg->desc[0].key = cpu_to_le32(req->mr->rkey);
1232 msg->desc[0].len = cpu_to_le32(req->mr->length);
1233
1234 /* Further invalidation is required */
1235 req->need_inv = !!RTRS_MSG_NEED_INVAL_F;
1236
1237 } else {
1238 msg->sg_cnt = 0;
1239 msg->flags = 0;
1240 }
1241 /*
1242 * rtrs message will be after the space reserved for disk data and
1243 * user message
1244 */
1245 imm = req->permit->mem_off + req->data_len + req->usr_len;
1246 imm = rtrs_to_io_req_imm(imm);
1247 buf_id = req->permit->mem_id;
1248
1249 req->sg_size = sizeof(*msg);
1250 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc);
1251 req->sg_size += req->usr_len;
1252
1253 /*
1254 * Update stats now, after request is successfully sent it is not
1255 * safe anymore to touch it.
1256 */
1257 rtrs_clt_update_all_stats(req, READ);
1258
1259 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id],
1260 req->data_len, imm, wr);
1261 if (ret) {
1262 rtrs_err_rl(s,
1263 "Read request failed: error=%d path=%s [%s:%u]\n",
1264 ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
1265 clt_path->hca_port);
1266 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
1267 atomic_dec(&clt_path->stats->inflight);
1268 req->need_inv = false;
1269 if (req->sg_cnt)
1270 ib_dma_unmap_sg(dev->ib_dev, req->sglist,
1271 req->sg_cnt, req->dir);
1272 }
1273
1274 return ret;
1275 }
1276
1277 /**
1278 * rtrs_clt_failover_req() - Try to find an active path for a failed request
1279 * @clt: clt context
1280 * @fail_req: a failed io request.
1281 */
rtrs_clt_failover_req(struct rtrs_clt_sess * clt,struct rtrs_clt_io_req * fail_req)1282 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt,
1283 struct rtrs_clt_io_req *fail_req)
1284 {
1285 struct rtrs_clt_path *alive_path;
1286 struct rtrs_clt_io_req *req;
1287 int err = -ECONNABORTED;
1288 struct path_it it;
1289
1290 rcu_read_lock();
1291 for (path_it_init(&it, clt);
1292 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num;
1293 it.i++) {
1294 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED)
1295 continue;
1296 req = rtrs_clt_get_copy_req(alive_path, fail_req);
1297 if (req->dir == DMA_TO_DEVICE)
1298 err = rtrs_clt_write_req(req);
1299 else
1300 err = rtrs_clt_read_req(req);
1301 if (err) {
1302 req->in_use = false;
1303 continue;
1304 }
1305 /* Success path */
1306 rtrs_clt_inc_failover_cnt(alive_path->stats);
1307 break;
1308 }
1309 path_it_deinit(&it);
1310 rcu_read_unlock();
1311
1312 return err;
1313 }
1314
fail_all_outstanding_reqs(struct rtrs_clt_path * clt_path)1315 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path)
1316 {
1317 struct rtrs_clt_sess *clt = clt_path->clt;
1318 struct rtrs_clt_io_req *req;
1319 int i, err;
1320
1321 if (!clt_path->reqs)
1322 return;
1323 for (i = 0; i < clt_path->queue_depth; ++i) {
1324 req = &clt_path->reqs[i];
1325 if (!req->in_use)
1326 continue;
1327
1328 /*
1329 * Safely (without notification) complete failed request.
1330 * After completion this request is still useble and can
1331 * be failovered to another path.
1332 */
1333 complete_rdma_req(req, -ECONNABORTED, false, true);
1334
1335 err = rtrs_clt_failover_req(clt, req);
1336 if (err)
1337 /* Failover failed, notify anyway */
1338 req->conf(req->priv, err);
1339 }
1340 }
1341
free_path_reqs(struct rtrs_clt_path * clt_path)1342 static void free_path_reqs(struct rtrs_clt_path *clt_path)
1343 {
1344 struct rtrs_clt_io_req *req;
1345 int i;
1346
1347 if (!clt_path->reqs)
1348 return;
1349 for (i = 0; i < clt_path->queue_depth; ++i) {
1350 req = &clt_path->reqs[i];
1351 if (req->mr)
1352 ib_dereg_mr(req->mr);
1353 kfree(req->sge);
1354 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1);
1355 }
1356 kfree(clt_path->reqs);
1357 clt_path->reqs = NULL;
1358 }
1359
alloc_path_reqs(struct rtrs_clt_path * clt_path)1360 static int alloc_path_reqs(struct rtrs_clt_path *clt_path)
1361 {
1362 struct rtrs_clt_io_req *req;
1363 int i, err = -ENOMEM;
1364
1365 clt_path->reqs = kcalloc(clt_path->queue_depth,
1366 sizeof(*clt_path->reqs),
1367 GFP_KERNEL);
1368 if (!clt_path->reqs)
1369 return -ENOMEM;
1370
1371 for (i = 0; i < clt_path->queue_depth; ++i) {
1372 req = &clt_path->reqs[i];
1373 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL,
1374 clt_path->s.dev->ib_dev,
1375 DMA_TO_DEVICE,
1376 rtrs_clt_rdma_done);
1377 if (!req->iu)
1378 goto out;
1379
1380 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL);
1381 if (!req->sge)
1382 goto out;
1383
1384 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd,
1385 IB_MR_TYPE_MEM_REG,
1386 clt_path->max_pages_per_mr);
1387 if (IS_ERR(req->mr)) {
1388 err = PTR_ERR(req->mr);
1389 req->mr = NULL;
1390 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n",
1391 clt_path->max_pages_per_mr);
1392 goto out;
1393 }
1394
1395 init_completion(&req->inv_comp);
1396 }
1397
1398 return 0;
1399
1400 out:
1401 free_path_reqs(clt_path);
1402
1403 return err;
1404 }
1405
alloc_permits(struct rtrs_clt_sess * clt)1406 static int alloc_permits(struct rtrs_clt_sess *clt)
1407 {
1408 unsigned int chunk_bits;
1409 int err, i;
1410
1411 clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL);
1412 if (!clt->permits_map) {
1413 err = -ENOMEM;
1414 goto out_err;
1415 }
1416 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL);
1417 if (!clt->permits) {
1418 err = -ENOMEM;
1419 goto err_map;
1420 }
1421 chunk_bits = ilog2(clt->queue_depth - 1) + 1;
1422 for (i = 0; i < clt->queue_depth; i++) {
1423 struct rtrs_permit *permit;
1424
1425 permit = get_permit(clt, i);
1426 permit->mem_id = i;
1427 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits);
1428 }
1429
1430 return 0;
1431
1432 err_map:
1433 bitmap_free(clt->permits_map);
1434 clt->permits_map = NULL;
1435 out_err:
1436 return err;
1437 }
1438
free_permits(struct rtrs_clt_sess * clt)1439 static void free_permits(struct rtrs_clt_sess *clt)
1440 {
1441 if (clt->permits_map)
1442 wait_event(clt->permits_wait,
1443 bitmap_empty(clt->permits_map, clt->queue_depth));
1444
1445 bitmap_free(clt->permits_map);
1446 clt->permits_map = NULL;
1447 kfree(clt->permits);
1448 clt->permits = NULL;
1449 }
1450
query_fast_reg_mode(struct rtrs_clt_path * clt_path)1451 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path)
1452 {
1453 struct ib_device *ib_dev;
1454 u64 max_pages_per_mr;
1455 int mr_page_shift;
1456
1457 ib_dev = clt_path->s.dev->ib_dev;
1458
1459 /*
1460 * Use the smallest page size supported by the HCA, down to a
1461 * minimum of 4096 bytes. We're unlikely to build large sglists
1462 * out of smaller entries.
1463 */
1464 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1);
1465 max_pages_per_mr = ib_dev->attrs.max_mr_size;
1466 do_div(max_pages_per_mr, (1ull << mr_page_shift));
1467 clt_path->max_pages_per_mr =
1468 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr,
1469 ib_dev->attrs.max_fast_reg_page_list_len);
1470 clt_path->clt->max_segments =
1471 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments);
1472 }
1473
rtrs_clt_change_state_get_old(struct rtrs_clt_path * clt_path,enum rtrs_clt_state new_state,enum rtrs_clt_state * old_state)1474 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path,
1475 enum rtrs_clt_state new_state,
1476 enum rtrs_clt_state *old_state)
1477 {
1478 bool changed;
1479
1480 spin_lock_irq(&clt_path->state_wq.lock);
1481 if (old_state)
1482 *old_state = clt_path->state;
1483 changed = rtrs_clt_change_state(clt_path, new_state);
1484 spin_unlock_irq(&clt_path->state_wq.lock);
1485
1486 return changed;
1487 }
1488
rtrs_clt_hb_err_handler(struct rtrs_con * c)1489 static void rtrs_clt_hb_err_handler(struct rtrs_con *c)
1490 {
1491 struct rtrs_clt_con *con = container_of(c, typeof(*con), c);
1492
1493 rtrs_rdma_error_recovery(con);
1494 }
1495
rtrs_clt_init_hb(struct rtrs_clt_path * clt_path)1496 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path)
1497 {
1498 rtrs_init_hb(&clt_path->s, &io_comp_cqe,
1499 RTRS_HB_INTERVAL_MS,
1500 RTRS_HB_MISSED_MAX,
1501 rtrs_clt_hb_err_handler,
1502 rtrs_wq);
1503 }
1504
1505 static void rtrs_clt_reconnect_work(struct work_struct *work);
1506 static void rtrs_clt_close_work(struct work_struct *work);
1507
rtrs_clt_err_recovery_work(struct work_struct * work)1508 static void rtrs_clt_err_recovery_work(struct work_struct *work)
1509 {
1510 struct rtrs_clt_path *clt_path;
1511 struct rtrs_clt_sess *clt;
1512 int delay_ms;
1513
1514 clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work);
1515 clt = clt_path->clt;
1516 delay_ms = clt->reconnect_delay_sec * 1000;
1517 rtrs_clt_stop_and_destroy_conns(clt_path);
1518 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
1519 msecs_to_jiffies(delay_ms +
1520 get_random_u32_below(RTRS_RECONNECT_SEED)));
1521 }
1522
alloc_path(struct rtrs_clt_sess * clt,const struct rtrs_addr * path,size_t con_num,u32 nr_poll_queues)1523 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
1524 const struct rtrs_addr *path,
1525 size_t con_num, u32 nr_poll_queues)
1526 {
1527 struct rtrs_clt_path *clt_path;
1528 int err = -ENOMEM;
1529 int cpu;
1530 size_t total_con;
1531
1532 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL);
1533 if (!clt_path)
1534 goto err;
1535
1536 /*
1537 * irqmode and poll
1538 * +1: Extra connection for user messages
1539 */
1540 total_con = con_num + nr_poll_queues + 1;
1541 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con),
1542 GFP_KERNEL);
1543 if (!clt_path->s.con)
1544 goto err_free_path;
1545
1546 clt_path->s.con_num = total_con;
1547 clt_path->s.irq_con_num = con_num + 1;
1548
1549 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL);
1550 if (!clt_path->stats)
1551 goto err_free_con;
1552
1553 mutex_init(&clt_path->init_mutex);
1554 uuid_gen(&clt_path->s.uuid);
1555 memcpy(&clt_path->s.dst_addr, path->dst,
1556 rdma_addr_size((struct sockaddr *)path->dst));
1557
1558 /*
1559 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which
1560 * checks the sa_family to be non-zero. If user passed src_addr=NULL
1561 * the sess->src_addr will contain only zeros, which is then fine.
1562 */
1563 if (path->src)
1564 memcpy(&clt_path->s.src_addr, path->src,
1565 rdma_addr_size((struct sockaddr *)path->src));
1566 strscpy(clt_path->s.sessname, clt->sessname,
1567 sizeof(clt_path->s.sessname));
1568 clt_path->clt = clt;
1569 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS;
1570 init_waitqueue_head(&clt_path->state_wq);
1571 clt_path->state = RTRS_CLT_CONNECTING;
1572 atomic_set(&clt_path->connected_cnt, 0);
1573 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work);
1574 INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work);
1575 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work);
1576 rtrs_clt_init_hb(clt_path);
1577
1578 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry));
1579 if (!clt_path->mp_skip_entry)
1580 goto err_free_stats;
1581
1582 for_each_possible_cpu(cpu)
1583 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu));
1584
1585 err = rtrs_clt_init_stats(clt_path->stats);
1586 if (err)
1587 goto err_free_percpu;
1588
1589 return clt_path;
1590
1591 err_free_percpu:
1592 free_percpu(clt_path->mp_skip_entry);
1593 err_free_stats:
1594 kfree(clt_path->stats);
1595 err_free_con:
1596 kfree(clt_path->s.con);
1597 err_free_path:
1598 kfree(clt_path);
1599 err:
1600 return ERR_PTR(err);
1601 }
1602
free_path(struct rtrs_clt_path * clt_path)1603 void free_path(struct rtrs_clt_path *clt_path)
1604 {
1605 free_percpu(clt_path->mp_skip_entry);
1606 mutex_destroy(&clt_path->init_mutex);
1607 kfree(clt_path->s.con);
1608 kfree(clt_path->rbufs);
1609 kfree(clt_path);
1610 }
1611
create_con(struct rtrs_clt_path * clt_path,unsigned int cid)1612 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid)
1613 {
1614 struct rtrs_clt_con *con;
1615
1616 con = kzalloc(sizeof(*con), GFP_KERNEL);
1617 if (!con)
1618 return -ENOMEM;
1619
1620 /* Map first two connections to the first CPU */
1621 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids;
1622 con->c.cid = cid;
1623 con->c.path = &clt_path->s;
1624 /* Align with srv, init as 1 */
1625 atomic_set(&con->c.wr_cnt, 1);
1626 mutex_init(&con->con_mutex);
1627
1628 clt_path->s.con[cid] = &con->c;
1629
1630 return 0;
1631 }
1632
destroy_con(struct rtrs_clt_con * con)1633 static void destroy_con(struct rtrs_clt_con *con)
1634 {
1635 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1636
1637 clt_path->s.con[con->c.cid] = NULL;
1638 mutex_destroy(&con->con_mutex);
1639 kfree(con);
1640 }
1641
create_con_cq_qp(struct rtrs_clt_con * con)1642 static int create_con_cq_qp(struct rtrs_clt_con *con)
1643 {
1644 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1645 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit;
1646 int err, cq_vector;
1647 struct rtrs_msg_rkey_rsp *rsp;
1648
1649 lockdep_assert_held(&con->con_mutex);
1650 if (con->c.cid == 0) {
1651 max_send_sge = 1;
1652 /* We must be the first here */
1653 if (WARN_ON(clt_path->s.dev))
1654 return -EINVAL;
1655
1656 /*
1657 * The whole session uses device from user connection.
1658 * Be careful not to close user connection before ib dev
1659 * is gracefully put.
1660 */
1661 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device,
1662 &dev_pd);
1663 if (!clt_path->s.dev) {
1664 rtrs_wrn(clt_path->clt,
1665 "rtrs_ib_dev_find_get_or_add(): no memory\n");
1666 return -ENOMEM;
1667 }
1668 clt_path->s.dev_ref = 1;
1669 query_fast_reg_mode(clt_path);
1670 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
1671 /*
1672 * Two (request + registration) completion for send
1673 * Two for recv if always_invalidate is set on server
1674 * or one for recv.
1675 * + 2 for drain and heartbeat
1676 * in case qp gets into error state.
1677 */
1678 max_send_wr =
1679 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2);
1680 max_recv_wr = max_send_wr;
1681 } else {
1682 /*
1683 * Here we assume that session members are correctly set.
1684 * This is always true if user connection (cid == 0) is
1685 * established first.
1686 */
1687 if (WARN_ON(!clt_path->s.dev))
1688 return -EINVAL;
1689 if (WARN_ON(!clt_path->queue_depth))
1690 return -EINVAL;
1691
1692 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
1693 /* Shared between connections */
1694 clt_path->s.dev_ref++;
1695 max_send_wr = min_t(int, wr_limit,
1696 /* QD * (REQ + RSP + FR REGS or INVS) + drain */
1697 clt_path->queue_depth * 3 + 1);
1698 max_recv_wr = min_t(int, wr_limit,
1699 clt_path->queue_depth * 3 + 1);
1700 max_send_sge = 2;
1701 }
1702 atomic_set(&con->c.sq_wr_avail, max_send_wr);
1703 cq_num = max_send_wr + max_recv_wr;
1704 /* alloc iu to recv new rkey reply when server reports flags set */
1705 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
1706 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp),
1707 GFP_KERNEL,
1708 clt_path->s.dev->ib_dev,
1709 DMA_FROM_DEVICE,
1710 rtrs_clt_rdma_done);
1711 if (!con->rsp_ius)
1712 return -ENOMEM;
1713 con->queue_num = cq_num;
1714 }
1715 cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors;
1716 if (con->c.cid >= clt_path->s.irq_con_num)
1717 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge,
1718 cq_vector, cq_num, max_send_wr,
1719 max_recv_wr, IB_POLL_DIRECT);
1720 else
1721 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge,
1722 cq_vector, cq_num, max_send_wr,
1723 max_recv_wr, IB_POLL_SOFTIRQ);
1724 /*
1725 * In case of error we do not bother to clean previous allocations,
1726 * since destroy_con_cq_qp() must be called.
1727 */
1728 return err;
1729 }
1730
destroy_con_cq_qp(struct rtrs_clt_con * con)1731 static void destroy_con_cq_qp(struct rtrs_clt_con *con)
1732 {
1733 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1734
1735 /*
1736 * Be careful here: destroy_con_cq_qp() can be called even
1737 * create_con_cq_qp() failed, see comments there.
1738 */
1739 lockdep_assert_held(&con->con_mutex);
1740 rtrs_cq_qp_destroy(&con->c);
1741 if (con->rsp_ius) {
1742 rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev,
1743 con->queue_num);
1744 con->rsp_ius = NULL;
1745 con->queue_num = 0;
1746 }
1747 if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) {
1748 rtrs_ib_dev_put(clt_path->s.dev);
1749 clt_path->s.dev = NULL;
1750 }
1751 }
1752
stop_cm(struct rtrs_clt_con * con)1753 static void stop_cm(struct rtrs_clt_con *con)
1754 {
1755 rdma_disconnect(con->c.cm_id);
1756 if (con->c.qp)
1757 ib_drain_qp(con->c.qp);
1758 }
1759
destroy_cm(struct rtrs_clt_con * con)1760 static void destroy_cm(struct rtrs_clt_con *con)
1761 {
1762 rdma_destroy_id(con->c.cm_id);
1763 con->c.cm_id = NULL;
1764 }
1765
rtrs_rdma_addr_resolved(struct rtrs_clt_con * con)1766 static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con)
1767 {
1768 struct rtrs_path *s = con->c.path;
1769 int err;
1770
1771 mutex_lock(&con->con_mutex);
1772 err = create_con_cq_qp(con);
1773 mutex_unlock(&con->con_mutex);
1774 if (err) {
1775 rtrs_err(s, "create_con_cq_qp(), err: %d\n", err);
1776 return err;
1777 }
1778 err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS);
1779 if (err)
1780 rtrs_err(s, "Resolving route failed, err: %d\n", err);
1781
1782 return err;
1783 }
1784
rtrs_rdma_route_resolved(struct rtrs_clt_con * con)1785 static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con)
1786 {
1787 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1788 struct rtrs_clt_sess *clt = clt_path->clt;
1789 struct rtrs_msg_conn_req msg;
1790 struct rdma_conn_param param;
1791
1792 int err;
1793
1794 param = (struct rdma_conn_param) {
1795 .retry_count = 7,
1796 .rnr_retry_count = 7,
1797 .private_data = &msg,
1798 .private_data_len = sizeof(msg),
1799 };
1800
1801 msg = (struct rtrs_msg_conn_req) {
1802 .magic = cpu_to_le16(RTRS_MAGIC),
1803 .version = cpu_to_le16(RTRS_PROTO_VER),
1804 .cid = cpu_to_le16(con->c.cid),
1805 .cid_num = cpu_to_le16(clt_path->s.con_num),
1806 .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt),
1807 };
1808 msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0;
1809 uuid_copy(&msg.sess_uuid, &clt_path->s.uuid);
1810 uuid_copy(&msg.paths_uuid, &clt->paths_uuid);
1811
1812 err = rdma_connect_locked(con->c.cm_id, ¶m);
1813 if (err)
1814 rtrs_err(clt, "rdma_connect_locked(): %d\n", err);
1815
1816 return err;
1817 }
1818
rtrs_rdma_conn_established(struct rtrs_clt_con * con,struct rdma_cm_event * ev)1819 static int rtrs_rdma_conn_established(struct rtrs_clt_con *con,
1820 struct rdma_cm_event *ev)
1821 {
1822 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1823 struct rtrs_clt_sess *clt = clt_path->clt;
1824 const struct rtrs_msg_conn_rsp *msg;
1825 u16 version, queue_depth;
1826 int errno;
1827 u8 len;
1828
1829 msg = ev->param.conn.private_data;
1830 len = ev->param.conn.private_data_len;
1831 if (len < sizeof(*msg)) {
1832 rtrs_err(clt, "Invalid RTRS connection response\n");
1833 return -ECONNRESET;
1834 }
1835 if (le16_to_cpu(msg->magic) != RTRS_MAGIC) {
1836 rtrs_err(clt, "Invalid RTRS magic\n");
1837 return -ECONNRESET;
1838 }
1839 version = le16_to_cpu(msg->version);
1840 if (version >> 8 != RTRS_PROTO_VER_MAJOR) {
1841 rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n",
1842 version >> 8, RTRS_PROTO_VER_MAJOR);
1843 return -ECONNRESET;
1844 }
1845 errno = le16_to_cpu(msg->errno);
1846 if (errno) {
1847 rtrs_err(clt, "Invalid RTRS message: errno %d\n",
1848 errno);
1849 return -ECONNRESET;
1850 }
1851 if (con->c.cid == 0) {
1852 queue_depth = le16_to_cpu(msg->queue_depth);
1853
1854 if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) {
1855 rtrs_err(clt, "Error: queue depth changed\n");
1856
1857 /*
1858 * Stop any more reconnection attempts
1859 */
1860 clt_path->reconnect_attempts = -1;
1861 rtrs_err(clt,
1862 "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n");
1863 return -ECONNRESET;
1864 }
1865
1866 if (!clt_path->rbufs) {
1867 clt_path->rbufs = kcalloc(queue_depth,
1868 sizeof(*clt_path->rbufs),
1869 GFP_KERNEL);
1870 if (!clt_path->rbufs)
1871 return -ENOMEM;
1872 }
1873 clt_path->queue_depth = queue_depth;
1874 clt_path->s.signal_interval = min_not_zero(queue_depth,
1875 (unsigned short) SERVICE_CON_QUEUE_DEPTH);
1876 clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size);
1877 clt_path->max_io_size = le32_to_cpu(msg->max_io_size);
1878 clt_path->flags = le32_to_cpu(msg->flags);
1879 clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size;
1880
1881 /*
1882 * Global IO size is always a minimum.
1883 * If while a reconnection server sends us a value a bit
1884 * higher - client does not care and uses cached minimum.
1885 *
1886 * Since we can have several sessions (paths) restablishing
1887 * connections in parallel, use lock.
1888 */
1889 mutex_lock(&clt->paths_mutex);
1890 clt->queue_depth = clt_path->queue_depth;
1891 clt->max_io_size = min_not_zero(clt_path->max_io_size,
1892 clt->max_io_size);
1893 mutex_unlock(&clt->paths_mutex);
1894
1895 /*
1896 * Cache the hca_port and hca_name for sysfs
1897 */
1898 clt_path->hca_port = con->c.cm_id->port_num;
1899 scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name),
1900 clt_path->s.dev->ib_dev->name);
1901 clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr;
1902 /* set for_new_clt, to allow future reconnect on any path */
1903 clt_path->for_new_clt = 1;
1904 }
1905
1906 return 0;
1907 }
1908
flag_success_on_conn(struct rtrs_clt_con * con)1909 static inline void flag_success_on_conn(struct rtrs_clt_con *con)
1910 {
1911 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1912
1913 atomic_inc(&clt_path->connected_cnt);
1914 con->cm_err = 1;
1915 }
1916
rtrs_rdma_conn_rejected(struct rtrs_clt_con * con,struct rdma_cm_event * ev)1917 static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con,
1918 struct rdma_cm_event *ev)
1919 {
1920 struct rtrs_path *s = con->c.path;
1921 const struct rtrs_msg_conn_rsp *msg;
1922 const char *rej_msg;
1923 int status, errno;
1924 u8 data_len;
1925
1926 status = ev->status;
1927 rej_msg = rdma_reject_msg(con->c.cm_id, status);
1928 msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len);
1929
1930 if (msg && data_len >= sizeof(*msg)) {
1931 errno = (int16_t)le16_to_cpu(msg->errno);
1932 if (errno == -EBUSY)
1933 rtrs_err(s,
1934 "Previous session is still exists on the server, please reconnect later\n");
1935 else
1936 rtrs_err(s,
1937 "Connect rejected: status %d (%s), rtrs errno %d\n",
1938 status, rej_msg, errno);
1939 } else {
1940 rtrs_err(s,
1941 "Connect rejected but with malformed message: status %d (%s)\n",
1942 status, rej_msg);
1943 }
1944
1945 return -ECONNRESET;
1946 }
1947
rtrs_clt_close_conns(struct rtrs_clt_path * clt_path,bool wait)1948 void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait)
1949 {
1950 trace_rtrs_clt_close_conns(clt_path);
1951
1952 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL))
1953 queue_work(rtrs_wq, &clt_path->close_work);
1954 if (wait)
1955 flush_work(&clt_path->close_work);
1956 }
1957
flag_error_on_conn(struct rtrs_clt_con * con,int cm_err)1958 static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err)
1959 {
1960 if (con->cm_err == 1) {
1961 struct rtrs_clt_path *clt_path;
1962
1963 clt_path = to_clt_path(con->c.path);
1964 if (atomic_dec_and_test(&clt_path->connected_cnt))
1965
1966 wake_up(&clt_path->state_wq);
1967 }
1968 con->cm_err = cm_err;
1969 }
1970
rtrs_clt_rdma_cm_handler(struct rdma_cm_id * cm_id,struct rdma_cm_event * ev)1971 static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id,
1972 struct rdma_cm_event *ev)
1973 {
1974 struct rtrs_clt_con *con = cm_id->context;
1975 struct rtrs_path *s = con->c.path;
1976 struct rtrs_clt_path *clt_path = to_clt_path(s);
1977 int cm_err = 0;
1978
1979 switch (ev->event) {
1980 case RDMA_CM_EVENT_ADDR_RESOLVED:
1981 cm_err = rtrs_rdma_addr_resolved(con);
1982 break;
1983 case RDMA_CM_EVENT_ROUTE_RESOLVED:
1984 cm_err = rtrs_rdma_route_resolved(con);
1985 break;
1986 case RDMA_CM_EVENT_ESTABLISHED:
1987 cm_err = rtrs_rdma_conn_established(con, ev);
1988 if (!cm_err) {
1989 /*
1990 * Report success and wake up. Here we abuse state_wq,
1991 * i.e. wake up without state change, but we set cm_err.
1992 */
1993 flag_success_on_conn(con);
1994 wake_up(&clt_path->state_wq);
1995 return 0;
1996 }
1997 break;
1998 case RDMA_CM_EVENT_REJECTED:
1999 cm_err = rtrs_rdma_conn_rejected(con, ev);
2000 break;
2001 case RDMA_CM_EVENT_DISCONNECTED:
2002 /* No message for disconnecting */
2003 cm_err = -ECONNRESET;
2004 break;
2005 case RDMA_CM_EVENT_CONNECT_ERROR:
2006 case RDMA_CM_EVENT_UNREACHABLE:
2007 case RDMA_CM_EVENT_ADDR_CHANGE:
2008 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2009 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n",
2010 rdma_event_msg(ev->event), ev->status);
2011 cm_err = -ECONNRESET;
2012 break;
2013 case RDMA_CM_EVENT_ADDR_ERROR:
2014 case RDMA_CM_EVENT_ROUTE_ERROR:
2015 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n",
2016 rdma_event_msg(ev->event), ev->status);
2017 cm_err = -EHOSTUNREACH;
2018 break;
2019 case RDMA_CM_EVENT_DEVICE_REMOVAL:
2020 /*
2021 * Device removal is a special case. Queue close and return 0.
2022 */
2023 rtrs_clt_close_conns(clt_path, false);
2024 return 0;
2025 default:
2026 rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n",
2027 rdma_event_msg(ev->event), ev->status);
2028 cm_err = -ECONNRESET;
2029 break;
2030 }
2031
2032 if (cm_err) {
2033 /*
2034 * cm error makes sense only on connection establishing,
2035 * in other cases we rely on normal procedure of reconnecting.
2036 */
2037 flag_error_on_conn(con, cm_err);
2038 rtrs_rdma_error_recovery(con);
2039 }
2040
2041 return 0;
2042 }
2043
2044 /* The caller should do the cleanup in case of error */
create_cm(struct rtrs_clt_con * con)2045 static int create_cm(struct rtrs_clt_con *con)
2046 {
2047 struct rtrs_path *s = con->c.path;
2048 struct rtrs_clt_path *clt_path = to_clt_path(s);
2049 struct rdma_cm_id *cm_id;
2050 int err;
2051
2052 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con,
2053 clt_path->s.dst_addr.ss_family == AF_IB ?
2054 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC);
2055 if (IS_ERR(cm_id)) {
2056 err = PTR_ERR(cm_id);
2057 rtrs_err(s, "Failed to create CM ID, err: %d\n", err);
2058
2059 return err;
2060 }
2061 con->c.cm_id = cm_id;
2062 con->cm_err = 0;
2063 /* allow the port to be reused */
2064 err = rdma_set_reuseaddr(cm_id, 1);
2065 if (err != 0) {
2066 rtrs_err(s, "Set address reuse failed, err: %d\n", err);
2067 return err;
2068 }
2069 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr,
2070 (struct sockaddr *)&clt_path->s.dst_addr,
2071 RTRS_CONNECT_TIMEOUT_MS);
2072 if (err) {
2073 rtrs_err(s, "Failed to resolve address, err: %d\n", err);
2074 return err;
2075 }
2076 /*
2077 * Combine connection status and session events. This is needed
2078 * for waiting two possible cases: cm_err has something meaningful
2079 * or session state was really changed to error by device removal.
2080 */
2081 err = wait_event_interruptible_timeout(
2082 clt_path->state_wq,
2083 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING,
2084 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
2085 if (err == 0 || err == -ERESTARTSYS) {
2086 if (err == 0)
2087 err = -ETIMEDOUT;
2088 /* Timedout or interrupted */
2089 return err;
2090 }
2091 if (con->cm_err < 0)
2092 return con->cm_err;
2093 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING)
2094 /* Device removal */
2095 return -ECONNABORTED;
2096
2097 return 0;
2098 }
2099
rtrs_clt_path_up(struct rtrs_clt_path * clt_path)2100 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path)
2101 {
2102 struct rtrs_clt_sess *clt = clt_path->clt;
2103 int up;
2104
2105 /*
2106 * We can fire RECONNECTED event only when all paths were
2107 * connected on rtrs_clt_open(), then each was disconnected
2108 * and the first one connected again. That's why this nasty
2109 * game with counter value.
2110 */
2111
2112 mutex_lock(&clt->paths_ev_mutex);
2113 up = ++clt->paths_up;
2114 /*
2115 * Here it is safe to access paths num directly since up counter
2116 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is
2117 * in progress, thus paths removals are impossible.
2118 */
2119 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num)
2120 clt->paths_up = clt->paths_num;
2121 else if (up == 1)
2122 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED);
2123 mutex_unlock(&clt->paths_ev_mutex);
2124
2125 /* Mark session as established */
2126 clt_path->established = true;
2127 clt_path->reconnect_attempts = 0;
2128 clt_path->stats->reconnects.successful_cnt++;
2129 }
2130
rtrs_clt_path_down(struct rtrs_clt_path * clt_path)2131 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path)
2132 {
2133 struct rtrs_clt_sess *clt = clt_path->clt;
2134
2135 if (!clt_path->established)
2136 return;
2137
2138 clt_path->established = false;
2139 mutex_lock(&clt->paths_ev_mutex);
2140 WARN_ON(!clt->paths_up);
2141 if (--clt->paths_up == 0)
2142 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED);
2143 mutex_unlock(&clt->paths_ev_mutex);
2144 }
2145
rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path * clt_path)2146 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path)
2147 {
2148 struct rtrs_clt_con *con;
2149 unsigned int cid;
2150
2151 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED);
2152
2153 /*
2154 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes
2155 * exactly in between. Start destroying after it finishes.
2156 */
2157 mutex_lock(&clt_path->init_mutex);
2158 mutex_unlock(&clt_path->init_mutex);
2159
2160 /*
2161 * All IO paths must observe !CONNECTED state before we
2162 * free everything.
2163 */
2164 synchronize_rcu();
2165
2166 rtrs_stop_hb(&clt_path->s);
2167
2168 /*
2169 * The order it utterly crucial: firstly disconnect and complete all
2170 * rdma requests with error (thus set in_use=false for requests),
2171 * then fail outstanding requests checking in_use for each, and
2172 * eventually notify upper layer about session disconnection.
2173 */
2174
2175 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2176 if (!clt_path->s.con[cid])
2177 break;
2178 con = to_clt_con(clt_path->s.con[cid]);
2179 stop_cm(con);
2180 }
2181 fail_all_outstanding_reqs(clt_path);
2182 free_path_reqs(clt_path);
2183 rtrs_clt_path_down(clt_path);
2184
2185 /*
2186 * Wait for graceful shutdown, namely when peer side invokes
2187 * rdma_disconnect(). 'connected_cnt' is decremented only on
2188 * CM events, thus if other side had crashed and hb has detected
2189 * something is wrong, here we will stuck for exactly timeout ms,
2190 * since CM does not fire anything. That is fine, we are not in
2191 * hurry.
2192 */
2193 wait_event_timeout(clt_path->state_wq,
2194 !atomic_read(&clt_path->connected_cnt),
2195 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
2196
2197 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2198 if (!clt_path->s.con[cid])
2199 break;
2200 con = to_clt_con(clt_path->s.con[cid]);
2201 mutex_lock(&con->con_mutex);
2202 destroy_con_cq_qp(con);
2203 mutex_unlock(&con->con_mutex);
2204 destroy_cm(con);
2205 destroy_con(con);
2206 }
2207 }
2208
rtrs_clt_remove_path_from_arr(struct rtrs_clt_path * clt_path)2209 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path)
2210 {
2211 struct rtrs_clt_sess *clt = clt_path->clt;
2212 struct rtrs_clt_path *next;
2213 bool wait_for_grace = false;
2214 int cpu;
2215
2216 mutex_lock(&clt->paths_mutex);
2217 list_del_rcu(&clt_path->s.entry);
2218
2219 /* Make sure everybody observes path removal. */
2220 synchronize_rcu();
2221
2222 /*
2223 * At this point nobody sees @sess in the list, but still we have
2224 * dangling pointer @pcpu_path which _can_ point to @sess. Since
2225 * nobody can observe @sess in the list, we guarantee that IO path
2226 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal
2227 * to @sess, but can never again become @sess.
2228 */
2229
2230 /*
2231 * Decrement paths number only after grace period, because
2232 * caller of do_each_path() must firstly observe list without
2233 * path and only then decremented paths number.
2234 *
2235 * Otherwise there can be the following situation:
2236 * o Two paths exist and IO is coming.
2237 * o One path is removed:
2238 * CPU#0 CPU#1
2239 * do_each_path(): rtrs_clt_remove_path_from_arr():
2240 * path = get_next_path()
2241 * ^^^ list_del_rcu(path)
2242 * [!CONNECTED path] clt->paths_num--
2243 * ^^^^^^^^^
2244 * load clt->paths_num from 2 to 1
2245 * ^^^^^^^^^
2246 * sees 1
2247 *
2248 * path is observed as !CONNECTED, but do_each_path() loop
2249 * ends, because expression i < clt->paths_num is false.
2250 */
2251 clt->paths_num--;
2252
2253 /*
2254 * Get @next connection from current @sess which is going to be
2255 * removed. If @sess is the last element, then @next is NULL.
2256 */
2257 rcu_read_lock();
2258 next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path);
2259 rcu_read_unlock();
2260
2261 /*
2262 * @pcpu paths can still point to the path which is going to be
2263 * removed, so change the pointer manually.
2264 */
2265 for_each_possible_cpu(cpu) {
2266 struct rtrs_clt_path __rcu **ppcpu_path;
2267
2268 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu);
2269 if (rcu_dereference_protected(*ppcpu_path,
2270 lockdep_is_held(&clt->paths_mutex)) != clt_path)
2271 /*
2272 * synchronize_rcu() was called just after deleting
2273 * entry from the list, thus IO code path cannot
2274 * change pointer back to the pointer which is going
2275 * to be removed, we are safe here.
2276 */
2277 continue;
2278
2279 /*
2280 * We race with IO code path, which also changes pointer,
2281 * thus we have to be careful not to overwrite it.
2282 */
2283 if (try_cmpxchg((struct rtrs_clt_path **)ppcpu_path, &clt_path,
2284 next))
2285 /*
2286 * @ppcpu_path was successfully replaced with @next,
2287 * that means that someone could also pick up the
2288 * @sess and dereferencing it right now, so wait for
2289 * a grace period is required.
2290 */
2291 wait_for_grace = true;
2292 }
2293 if (wait_for_grace)
2294 synchronize_rcu();
2295
2296 mutex_unlock(&clt->paths_mutex);
2297 }
2298
rtrs_clt_add_path_to_arr(struct rtrs_clt_path * clt_path)2299 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path)
2300 {
2301 struct rtrs_clt_sess *clt = clt_path->clt;
2302
2303 mutex_lock(&clt->paths_mutex);
2304 clt->paths_num++;
2305
2306 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
2307 mutex_unlock(&clt->paths_mutex);
2308 }
2309
rtrs_clt_close_work(struct work_struct * work)2310 static void rtrs_clt_close_work(struct work_struct *work)
2311 {
2312 struct rtrs_clt_path *clt_path;
2313
2314 clt_path = container_of(work, struct rtrs_clt_path, close_work);
2315
2316 cancel_work_sync(&clt_path->err_recovery_work);
2317 cancel_delayed_work_sync(&clt_path->reconnect_dwork);
2318 rtrs_clt_stop_and_destroy_conns(clt_path);
2319 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL);
2320 }
2321
init_conns(struct rtrs_clt_path * clt_path)2322 static int init_conns(struct rtrs_clt_path *clt_path)
2323 {
2324 unsigned int cid;
2325 int err, i;
2326
2327 /*
2328 * On every new session connections increase reconnect counter
2329 * to avoid clashes with previous sessions not yet closed
2330 * sessions on a server side.
2331 */
2332 clt_path->s.recon_cnt++;
2333
2334 /* Establish all RDMA connections */
2335 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2336 err = create_con(clt_path, cid);
2337 if (err)
2338 goto destroy;
2339
2340 err = create_cm(to_clt_con(clt_path->s.con[cid]));
2341 if (err)
2342 goto destroy;
2343 }
2344 err = alloc_path_reqs(clt_path);
2345 if (err)
2346 goto destroy;
2347
2348 rtrs_start_hb(&clt_path->s);
2349
2350 return 0;
2351
2352 destroy:
2353 /* Make sure we do the cleanup in the order they are created */
2354 for (i = 0; i <= cid; i++) {
2355 struct rtrs_clt_con *con;
2356
2357 if (!clt_path->s.con[i])
2358 break;
2359
2360 con = to_clt_con(clt_path->s.con[i]);
2361 if (con->c.cm_id) {
2362 stop_cm(con);
2363 mutex_lock(&con->con_mutex);
2364 destroy_con_cq_qp(con);
2365 mutex_unlock(&con->con_mutex);
2366 destroy_cm(con);
2367 }
2368 destroy_con(con);
2369 }
2370 /*
2371 * If we've never taken async path and got an error, say,
2372 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state
2373 * manually to keep reconnecting.
2374 */
2375 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
2376
2377 return err;
2378 }
2379
rtrs_clt_info_req_done(struct ib_cq * cq,struct ib_wc * wc)2380 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc)
2381 {
2382 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
2383 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
2384 struct rtrs_iu *iu;
2385
2386 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
2387 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
2388
2389 if (wc->status != IB_WC_SUCCESS) {
2390 rtrs_err(clt_path->clt, "Path info request send failed: %s\n",
2391 ib_wc_status_msg(wc->status));
2392 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
2393 return;
2394 }
2395
2396 rtrs_clt_update_wc_stats(con);
2397 }
2398
process_info_rsp(struct rtrs_clt_path * clt_path,const struct rtrs_msg_info_rsp * msg)2399 static int process_info_rsp(struct rtrs_clt_path *clt_path,
2400 const struct rtrs_msg_info_rsp *msg)
2401 {
2402 unsigned int sg_cnt, total_len;
2403 int i, sgi;
2404
2405 sg_cnt = le16_to_cpu(msg->sg_cnt);
2406 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) {
2407 rtrs_err(clt_path->clt,
2408 "Incorrect sg_cnt %d, is not multiple\n",
2409 sg_cnt);
2410 return -EINVAL;
2411 }
2412
2413 /*
2414 * Check if IB immediate data size is enough to hold the mem_id and
2415 * the offset inside the memory chunk.
2416 */
2417 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) >
2418 MAX_IMM_PAYL_BITS) {
2419 rtrs_err(clt_path->clt,
2420 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n",
2421 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size);
2422 return -EINVAL;
2423 }
2424 total_len = 0;
2425 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) {
2426 const struct rtrs_sg_desc *desc = &msg->desc[sgi];
2427 u32 len, rkey;
2428 u64 addr;
2429
2430 addr = le64_to_cpu(desc->addr);
2431 rkey = le32_to_cpu(desc->key);
2432 len = le32_to_cpu(desc->len);
2433
2434 total_len += len;
2435
2436 if (!len || (len % clt_path->chunk_size)) {
2437 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n",
2438 sgi,
2439 len);
2440 return -EINVAL;
2441 }
2442 for ( ; len && i < clt_path->queue_depth; i++) {
2443 clt_path->rbufs[i].addr = addr;
2444 clt_path->rbufs[i].rkey = rkey;
2445
2446 len -= clt_path->chunk_size;
2447 addr += clt_path->chunk_size;
2448 }
2449 }
2450 /* Sanity check */
2451 if (sgi != sg_cnt || i != clt_path->queue_depth) {
2452 rtrs_err(clt_path->clt,
2453 "Incorrect sg vector, not fully mapped\n");
2454 return -EINVAL;
2455 }
2456 if (total_len != clt_path->chunk_size * clt_path->queue_depth) {
2457 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len);
2458 return -EINVAL;
2459 }
2460
2461 return 0;
2462 }
2463
rtrs_clt_info_rsp_done(struct ib_cq * cq,struct ib_wc * wc)2464 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc)
2465 {
2466 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
2467 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
2468 struct rtrs_msg_info_rsp *msg;
2469 enum rtrs_clt_state state;
2470 struct rtrs_iu *iu;
2471 size_t rx_sz;
2472 int err;
2473
2474 state = RTRS_CLT_CONNECTING_ERR;
2475
2476 WARN_ON(con->c.cid);
2477 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
2478 if (wc->status != IB_WC_SUCCESS) {
2479 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n",
2480 ib_wc_status_msg(wc->status));
2481 goto out;
2482 }
2483 WARN_ON(wc->opcode != IB_WC_RECV);
2484
2485 if (wc->byte_len < sizeof(*msg)) {
2486 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
2487 wc->byte_len);
2488 goto out;
2489 }
2490 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
2491 iu->size, DMA_FROM_DEVICE);
2492 msg = iu->buf;
2493 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) {
2494 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n",
2495 le16_to_cpu(msg->type));
2496 goto out;
2497 }
2498 rx_sz = sizeof(*msg);
2499 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt);
2500 if (wc->byte_len < rx_sz) {
2501 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
2502 wc->byte_len);
2503 goto out;
2504 }
2505 err = process_info_rsp(clt_path, msg);
2506 if (err)
2507 goto out;
2508
2509 err = post_recv_path(clt_path);
2510 if (err)
2511 goto out;
2512
2513 state = RTRS_CLT_CONNECTED;
2514
2515 out:
2516 rtrs_clt_update_wc_stats(con);
2517 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
2518 rtrs_clt_change_state_get_old(clt_path, state, NULL);
2519 }
2520
rtrs_send_path_info(struct rtrs_clt_path * clt_path)2521 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path)
2522 {
2523 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]);
2524 struct rtrs_msg_info_req *msg;
2525 struct rtrs_iu *tx_iu, *rx_iu;
2526 size_t rx_sz;
2527 int err;
2528
2529 rx_sz = sizeof(struct rtrs_msg_info_rsp);
2530 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth;
2531
2532 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL,
2533 clt_path->s.dev->ib_dev, DMA_TO_DEVICE,
2534 rtrs_clt_info_req_done);
2535 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev,
2536 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done);
2537 if (!tx_iu || !rx_iu) {
2538 err = -ENOMEM;
2539 goto out;
2540 }
2541 /* Prepare for getting info response */
2542 err = rtrs_iu_post_recv(&usr_con->c, rx_iu);
2543 if (err) {
2544 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err);
2545 goto out;
2546 }
2547 rx_iu = NULL;
2548
2549 msg = tx_iu->buf;
2550 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ);
2551 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname));
2552
2553 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
2554 tx_iu->dma_addr,
2555 tx_iu->size, DMA_TO_DEVICE);
2556
2557 /* Send info request */
2558 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL);
2559 if (err) {
2560 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err);
2561 goto out;
2562 }
2563 tx_iu = NULL;
2564
2565 /* Wait for state change */
2566 wait_event_interruptible_timeout(clt_path->state_wq,
2567 clt_path->state != RTRS_CLT_CONNECTING,
2568 msecs_to_jiffies(
2569 RTRS_CONNECT_TIMEOUT_MS));
2570 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) {
2571 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR)
2572 err = -ECONNRESET;
2573 else
2574 err = -ETIMEDOUT;
2575 }
2576
2577 out:
2578 if (tx_iu)
2579 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1);
2580 if (rx_iu)
2581 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1);
2582 if (err)
2583 /* If we've never taken async path because of malloc problems */
2584 rtrs_clt_change_state_get_old(clt_path,
2585 RTRS_CLT_CONNECTING_ERR, NULL);
2586
2587 return err;
2588 }
2589
2590 /**
2591 * init_path() - establishes all path connections and does handshake
2592 * @clt_path: client path.
2593 * In case of error full close or reconnect procedure should be taken,
2594 * because reconnect or close async works can be started.
2595 */
init_path(struct rtrs_clt_path * clt_path)2596 static int init_path(struct rtrs_clt_path *clt_path)
2597 {
2598 int err;
2599 char str[NAME_MAX];
2600 struct rtrs_addr path = {
2601 .src = &clt_path->s.src_addr,
2602 .dst = &clt_path->s.dst_addr,
2603 };
2604
2605 rtrs_addr_to_str(&path, str, sizeof(str));
2606
2607 mutex_lock(&clt_path->init_mutex);
2608 err = init_conns(clt_path);
2609 if (err) {
2610 rtrs_err(clt_path->clt,
2611 "init_conns() failed: err=%d path=%s [%s:%u]\n", err,
2612 str, clt_path->hca_name, clt_path->hca_port);
2613 goto out;
2614 }
2615 err = rtrs_send_path_info(clt_path);
2616 if (err) {
2617 rtrs_err(clt_path->clt,
2618 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n",
2619 err, str, clt_path->hca_name, clt_path->hca_port);
2620 goto out;
2621 }
2622 rtrs_clt_path_up(clt_path);
2623 out:
2624 mutex_unlock(&clt_path->init_mutex);
2625
2626 return err;
2627 }
2628
rtrs_clt_reconnect_work(struct work_struct * work)2629 static void rtrs_clt_reconnect_work(struct work_struct *work)
2630 {
2631 struct rtrs_clt_path *clt_path;
2632 struct rtrs_clt_sess *clt;
2633 int err;
2634
2635 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path,
2636 reconnect_dwork);
2637 clt = clt_path->clt;
2638
2639 trace_rtrs_clt_reconnect_work(clt_path);
2640
2641 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING)
2642 return;
2643
2644 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) {
2645 /* Close a path completely if max attempts is reached */
2646 rtrs_clt_close_conns(clt_path, false);
2647 return;
2648 }
2649 clt_path->reconnect_attempts++;
2650
2651 msleep(RTRS_RECONNECT_BACKOFF);
2652 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) {
2653 err = init_path(clt_path);
2654 if (err)
2655 goto reconnect_again;
2656 }
2657
2658 return;
2659
2660 reconnect_again:
2661 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) {
2662 clt_path->stats->reconnects.fail_cnt++;
2663 queue_work(rtrs_wq, &clt_path->err_recovery_work);
2664 }
2665 }
2666
rtrs_clt_dev_release(struct device * dev)2667 static void rtrs_clt_dev_release(struct device *dev)
2668 {
2669 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess,
2670 dev);
2671
2672 mutex_destroy(&clt->paths_ev_mutex);
2673 mutex_destroy(&clt->paths_mutex);
2674 kfree(clt);
2675 }
2676
alloc_clt(const char * sessname,size_t paths_num,u16 port,size_t pdu_sz,void * priv,void (* link_ev)(void * priv,enum rtrs_clt_link_ev ev),unsigned int reconnect_delay_sec,unsigned int max_reconnect_attempts)2677 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num,
2678 u16 port, size_t pdu_sz, void *priv,
2679 void (*link_ev)(void *priv,
2680 enum rtrs_clt_link_ev ev),
2681 unsigned int reconnect_delay_sec,
2682 unsigned int max_reconnect_attempts)
2683 {
2684 struct rtrs_clt_sess *clt;
2685 int err;
2686
2687 if (!paths_num || paths_num > MAX_PATHS_NUM)
2688 return ERR_PTR(-EINVAL);
2689
2690 if (strlen(sessname) >= sizeof(clt->sessname))
2691 return ERR_PTR(-EINVAL);
2692
2693 clt = kzalloc(sizeof(*clt), GFP_KERNEL);
2694 if (!clt)
2695 return ERR_PTR(-ENOMEM);
2696
2697 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path));
2698 if (!clt->pcpu_path) {
2699 kfree(clt);
2700 return ERR_PTR(-ENOMEM);
2701 }
2702
2703 clt->dev.class = &rtrs_clt_dev_class;
2704 clt->dev.release = rtrs_clt_dev_release;
2705 uuid_gen(&clt->paths_uuid);
2706 INIT_LIST_HEAD_RCU(&clt->paths_list);
2707 clt->paths_num = paths_num;
2708 clt->paths_up = MAX_PATHS_NUM;
2709 clt->port = port;
2710 clt->pdu_sz = pdu_sz;
2711 clt->max_segments = RTRS_MAX_SEGMENTS;
2712 clt->reconnect_delay_sec = reconnect_delay_sec;
2713 clt->max_reconnect_attempts = max_reconnect_attempts;
2714 clt->priv = priv;
2715 clt->link_ev = link_ev;
2716 clt->mp_policy = MP_POLICY_MIN_INFLIGHT;
2717 strscpy(clt->sessname, sessname, sizeof(clt->sessname));
2718 init_waitqueue_head(&clt->permits_wait);
2719 mutex_init(&clt->paths_ev_mutex);
2720 mutex_init(&clt->paths_mutex);
2721 device_initialize(&clt->dev);
2722
2723 err = dev_set_name(&clt->dev, "%s", sessname);
2724 if (err)
2725 goto err_put;
2726
2727 /*
2728 * Suppress user space notification until
2729 * sysfs files are created
2730 */
2731 dev_set_uevent_suppress(&clt->dev, true);
2732 err = device_add(&clt->dev);
2733 if (err)
2734 goto err_put;
2735
2736 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj);
2737 if (!clt->kobj_paths) {
2738 err = -ENOMEM;
2739 goto err_del;
2740 }
2741 err = rtrs_clt_create_sysfs_root_files(clt);
2742 if (err) {
2743 kobject_del(clt->kobj_paths);
2744 kobject_put(clt->kobj_paths);
2745 goto err_del;
2746 }
2747 dev_set_uevent_suppress(&clt->dev, false);
2748 kobject_uevent(&clt->dev.kobj, KOBJ_ADD);
2749
2750 return clt;
2751 err_del:
2752 device_del(&clt->dev);
2753 err_put:
2754 free_percpu(clt->pcpu_path);
2755 put_device(&clt->dev);
2756 return ERR_PTR(err);
2757 }
2758
free_clt(struct rtrs_clt_sess * clt)2759 static void free_clt(struct rtrs_clt_sess *clt)
2760 {
2761 free_percpu(clt->pcpu_path);
2762
2763 /*
2764 * release callback will free clt and destroy mutexes in last put
2765 */
2766 device_unregister(&clt->dev);
2767 }
2768
2769 /**
2770 * rtrs_clt_open() - Open a path to an RTRS server
2771 * @ops: holds the link event callback and the private pointer.
2772 * @pathname: name of the path to an RTRS server
2773 * @paths: Paths to be established defined by their src and dst addresses
2774 * @paths_num: Number of elements in the @paths array
2775 * @port: port to be used by the RTRS session
2776 * @pdu_sz: Size of extra payload which can be accessed after permit allocation.
2777 * @reconnect_delay_sec: time between reconnect tries
2778 * @max_reconnect_attempts: Number of times to reconnect on error before giving
2779 * up, 0 for * disabled, -1 for forever
2780 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag
2781 *
2782 * Starts session establishment with the rtrs_server. The function can block
2783 * up to ~2000ms before it returns.
2784 *
2785 * Return a valid pointer on success otherwise PTR_ERR.
2786 */
rtrs_clt_open(struct rtrs_clt_ops * ops,const char * pathname,const struct rtrs_addr * paths,size_t paths_num,u16 port,size_t pdu_sz,u8 reconnect_delay_sec,s16 max_reconnect_attempts,u32 nr_poll_queues)2787 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops,
2788 const char *pathname,
2789 const struct rtrs_addr *paths,
2790 size_t paths_num, u16 port,
2791 size_t pdu_sz, u8 reconnect_delay_sec,
2792 s16 max_reconnect_attempts, u32 nr_poll_queues)
2793 {
2794 struct rtrs_clt_path *clt_path, *tmp;
2795 struct rtrs_clt_sess *clt;
2796 int err, i;
2797
2798 if (strchr(pathname, '/') || strchr(pathname, '.')) {
2799 pr_err("pathname cannot contain / and .\n");
2800 err = -EINVAL;
2801 goto out;
2802 }
2803
2804 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv,
2805 ops->link_ev,
2806 reconnect_delay_sec,
2807 max_reconnect_attempts);
2808 if (IS_ERR(clt)) {
2809 err = PTR_ERR(clt);
2810 goto out;
2811 }
2812 for (i = 0; i < paths_num; i++) {
2813 struct rtrs_clt_path *clt_path;
2814
2815 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids,
2816 nr_poll_queues);
2817 if (IS_ERR(clt_path)) {
2818 err = PTR_ERR(clt_path);
2819 goto close_all_path;
2820 }
2821 if (!i)
2822 clt_path->for_new_clt = 1;
2823 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
2824
2825 err = init_path(clt_path);
2826 if (err) {
2827 list_del_rcu(&clt_path->s.entry);
2828 rtrs_clt_close_conns(clt_path, true);
2829 free_percpu(clt_path->stats->pcpu_stats);
2830 kfree(clt_path->stats);
2831 free_path(clt_path);
2832 goto close_all_path;
2833 }
2834
2835 err = rtrs_clt_create_path_files(clt_path);
2836 if (err) {
2837 list_del_rcu(&clt_path->s.entry);
2838 rtrs_clt_close_conns(clt_path, true);
2839 free_percpu(clt_path->stats->pcpu_stats);
2840 kfree(clt_path->stats);
2841 free_path(clt_path);
2842 goto close_all_path;
2843 }
2844 }
2845 err = alloc_permits(clt);
2846 if (err)
2847 goto close_all_path;
2848
2849 return clt;
2850
2851 close_all_path:
2852 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
2853 rtrs_clt_destroy_path_files(clt_path, NULL);
2854 rtrs_clt_close_conns(clt_path, true);
2855 kobject_put(&clt_path->kobj);
2856 }
2857 rtrs_clt_destroy_sysfs_root(clt);
2858 free_clt(clt);
2859
2860 out:
2861 return ERR_PTR(err);
2862 }
2863 EXPORT_SYMBOL(rtrs_clt_open);
2864
2865 /**
2866 * rtrs_clt_close() - Close a path
2867 * @clt: Session handle. Session is freed upon return.
2868 */
rtrs_clt_close(struct rtrs_clt_sess * clt)2869 void rtrs_clt_close(struct rtrs_clt_sess *clt)
2870 {
2871 struct rtrs_clt_path *clt_path, *tmp;
2872
2873 /* Firstly forbid sysfs access */
2874 rtrs_clt_destroy_sysfs_root(clt);
2875
2876 /* Now it is safe to iterate over all paths without locks */
2877 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
2878 rtrs_clt_close_conns(clt_path, true);
2879 rtrs_clt_destroy_path_files(clt_path, NULL);
2880 kobject_put(&clt_path->kobj);
2881 }
2882 free_permits(clt);
2883 free_clt(clt);
2884 }
2885 EXPORT_SYMBOL(rtrs_clt_close);
2886
rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path * clt_path)2887 int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path)
2888 {
2889 enum rtrs_clt_state old_state;
2890 int err = -EBUSY;
2891 bool changed;
2892
2893 changed = rtrs_clt_change_state_get_old(clt_path,
2894 RTRS_CLT_RECONNECTING,
2895 &old_state);
2896 if (changed) {
2897 clt_path->reconnect_attempts = 0;
2898 rtrs_clt_stop_and_destroy_conns(clt_path);
2899 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0);
2900 }
2901 if (changed || old_state == RTRS_CLT_RECONNECTING) {
2902 /*
2903 * flush_delayed_work() queues pending work for immediate
2904 * execution, so do the flush if we have queued something
2905 * right now or work is pending.
2906 */
2907 flush_delayed_work(&clt_path->reconnect_dwork);
2908 err = (READ_ONCE(clt_path->state) ==
2909 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN);
2910 }
2911
2912 return err;
2913 }
2914
rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path * clt_path,const struct attribute * sysfs_self)2915 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path,
2916 const struct attribute *sysfs_self)
2917 {
2918 enum rtrs_clt_state old_state;
2919 bool changed;
2920
2921 /*
2922 * Continue stopping path till state was changed to DEAD or
2923 * state was observed as DEAD:
2924 * 1. State was changed to DEAD - we were fast and nobody
2925 * invoked rtrs_clt_reconnect(), which can again start
2926 * reconnecting.
2927 * 2. State was observed as DEAD - we have someone in parallel
2928 * removing the path.
2929 */
2930 do {
2931 rtrs_clt_close_conns(clt_path, true);
2932 changed = rtrs_clt_change_state_get_old(clt_path,
2933 RTRS_CLT_DEAD,
2934 &old_state);
2935 } while (!changed && old_state != RTRS_CLT_DEAD);
2936
2937 if (changed) {
2938 rtrs_clt_remove_path_from_arr(clt_path);
2939 rtrs_clt_destroy_path_files(clt_path, sysfs_self);
2940 kobject_put(&clt_path->kobj);
2941 }
2942
2943 return 0;
2944 }
2945
rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess * clt,int value)2946 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value)
2947 {
2948 clt->max_reconnect_attempts = (unsigned int)value;
2949 }
2950
rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess * clt)2951 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt)
2952 {
2953 return (int)clt->max_reconnect_attempts;
2954 }
2955
2956 /**
2957 * rtrs_clt_request() - Request data transfer to/from server via RDMA.
2958 *
2959 * @dir: READ/WRITE
2960 * @ops: callback function to be called as confirmation, and the pointer.
2961 * @clt: Session
2962 * @permit: Preallocated permit
2963 * @vec: Message that is sent to server together with the request.
2964 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE.
2965 * Since the msg is copied internally it can be allocated on stack.
2966 * @nr: Number of elements in @vec.
2967 * @data_len: length of data sent to/from server
2968 * @sg: Pages to be sent/received to/from server.
2969 * @sg_cnt: Number of elements in the @sg
2970 *
2971 * Return:
2972 * 0: Success
2973 * <0: Error
2974 *
2975 * On dir=READ rtrs client will request a data transfer from Server to client.
2976 * The data that the server will respond with will be stored in @sg when
2977 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event.
2978 * On dir=WRITE rtrs client will rdma write data in sg to server side.
2979 */
rtrs_clt_request(int dir,struct rtrs_clt_req_ops * ops,struct rtrs_clt_sess * clt,struct rtrs_permit * permit,const struct kvec * vec,size_t nr,size_t data_len,struct scatterlist * sg,unsigned int sg_cnt)2980 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
2981 struct rtrs_clt_sess *clt, struct rtrs_permit *permit,
2982 const struct kvec *vec, size_t nr, size_t data_len,
2983 struct scatterlist *sg, unsigned int sg_cnt)
2984 {
2985 struct rtrs_clt_io_req *req;
2986 struct rtrs_clt_path *clt_path;
2987
2988 enum dma_data_direction dma_dir;
2989 int err = -ECONNABORTED, i;
2990 size_t usr_len, hdr_len;
2991 struct path_it it;
2992
2993 /* Get kvec length */
2994 for (i = 0, usr_len = 0; i < nr; i++)
2995 usr_len += vec[i].iov_len;
2996
2997 if (dir == READ) {
2998 hdr_len = sizeof(struct rtrs_msg_rdma_read) +
2999 sg_cnt * sizeof(struct rtrs_sg_desc);
3000 dma_dir = DMA_FROM_DEVICE;
3001 } else {
3002 hdr_len = sizeof(struct rtrs_msg_rdma_write);
3003 dma_dir = DMA_TO_DEVICE;
3004 }
3005
3006 rcu_read_lock();
3007 for (path_it_init(&it, clt);
3008 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
3009 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
3010 continue;
3011
3012 if (usr_len + hdr_len > clt_path->max_hdr_size) {
3013 rtrs_wrn_rl(clt_path->clt,
3014 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n",
3015 dir == READ ? "Read" : "Write",
3016 usr_len, hdr_len, clt_path->max_hdr_size);
3017 err = -EMSGSIZE;
3018 break;
3019 }
3020 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv,
3021 vec, usr_len, sg, sg_cnt, data_len,
3022 dma_dir);
3023 if (dir == READ)
3024 err = rtrs_clt_read_req(req);
3025 else
3026 err = rtrs_clt_write_req(req);
3027 if (err) {
3028 req->in_use = false;
3029 continue;
3030 }
3031 /* Success path */
3032 break;
3033 }
3034 path_it_deinit(&it);
3035 rcu_read_unlock();
3036
3037 return err;
3038 }
3039 EXPORT_SYMBOL(rtrs_clt_request);
3040
rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess * clt,unsigned int index)3041 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index)
3042 {
3043 /* If no path, return -1 for block layer not to try again */
3044 int cnt = -1;
3045 struct rtrs_con *con;
3046 struct rtrs_clt_path *clt_path;
3047 struct path_it it;
3048
3049 rcu_read_lock();
3050 for (path_it_init(&it, clt);
3051 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
3052 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
3053 continue;
3054
3055 con = clt_path->s.con[index + 1];
3056 cnt = ib_process_cq_direct(con->cq, -1);
3057 if (cnt)
3058 break;
3059 }
3060 path_it_deinit(&it);
3061 rcu_read_unlock();
3062
3063 return cnt;
3064 }
3065 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct);
3066
3067 /**
3068 * rtrs_clt_query() - queries RTRS session attributes
3069 *@clt: session pointer
3070 *@attr: query results for session attributes.
3071 * Returns:
3072 * 0 on success
3073 * -ECOMM no connection to the server
3074 */
rtrs_clt_query(struct rtrs_clt_sess * clt,struct rtrs_attrs * attr)3075 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr)
3076 {
3077 if (!rtrs_clt_is_connected(clt))
3078 return -ECOMM;
3079
3080 attr->queue_depth = clt->queue_depth;
3081 attr->max_segments = clt->max_segments;
3082 /* Cap max_io_size to min of remote buffer size and the fr pages */
3083 attr->max_io_size = min_t(int, clt->max_io_size,
3084 clt->max_segments * SZ_4K);
3085
3086 return 0;
3087 }
3088 EXPORT_SYMBOL(rtrs_clt_query);
3089
rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess * clt,struct rtrs_addr * addr)3090 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt,
3091 struct rtrs_addr *addr)
3092 {
3093 struct rtrs_clt_path *clt_path;
3094 int err;
3095
3096 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0);
3097 if (IS_ERR(clt_path))
3098 return PTR_ERR(clt_path);
3099
3100 mutex_lock(&clt->paths_mutex);
3101 if (clt->paths_num == 0) {
3102 /*
3103 * When all the paths are removed for a session,
3104 * the addition of the first path is like a new session for
3105 * the storage server
3106 */
3107 clt_path->for_new_clt = 1;
3108 }
3109
3110 mutex_unlock(&clt->paths_mutex);
3111
3112 /*
3113 * It is totally safe to add path in CONNECTING state: coming
3114 * IO will never grab it. Also it is very important to add
3115 * path before init, since init fires LINK_CONNECTED event.
3116 */
3117 rtrs_clt_add_path_to_arr(clt_path);
3118
3119 err = init_path(clt_path);
3120 if (err)
3121 goto close_path;
3122
3123 err = rtrs_clt_create_path_files(clt_path);
3124 if (err)
3125 goto close_path;
3126
3127 return 0;
3128
3129 close_path:
3130 rtrs_clt_remove_path_from_arr(clt_path);
3131 rtrs_clt_close_conns(clt_path, true);
3132 free_percpu(clt_path->stats->pcpu_stats);
3133 kfree(clt_path->stats);
3134 free_path(clt_path);
3135
3136 return err;
3137 }
3138
rtrs_clt_ib_dev_init(struct rtrs_ib_dev * dev)3139 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev)
3140 {
3141 if (!(dev->ib_dev->attrs.device_cap_flags &
3142 IB_DEVICE_MEM_MGT_EXTENSIONS)) {
3143 pr_err("Memory registrations not supported.\n");
3144 return -ENOTSUPP;
3145 }
3146
3147 return 0;
3148 }
3149
3150 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = {
3151 .init = rtrs_clt_ib_dev_init
3152 };
3153
rtrs_client_init(void)3154 static int __init rtrs_client_init(void)
3155 {
3156 int ret = 0;
3157
3158 rtrs_rdma_dev_pd_init(0, &dev_pd);
3159 ret = class_register(&rtrs_clt_dev_class);
3160 if (ret) {
3161 pr_err("Failed to create rtrs-client dev class\n");
3162 return ret;
3163 }
3164 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0);
3165 if (!rtrs_wq) {
3166 class_unregister(&rtrs_clt_dev_class);
3167 return -ENOMEM;
3168 }
3169
3170 return 0;
3171 }
3172
rtrs_client_exit(void)3173 static void __exit rtrs_client_exit(void)
3174 {
3175 destroy_workqueue(rtrs_wq);
3176 class_unregister(&rtrs_clt_dev_class);
3177 rtrs_rdma_dev_pd_deinit(&dev_pd);
3178 }
3179
3180 module_init(rtrs_client_init);
3181 module_exit(rtrs_client_exit);
3182
