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 (!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 clt_path->s.hb_missed_cnt = 0;
630 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
631 &imm_type, &imm_payload);
632 if (imm_type == RTRS_IO_RSP_IMM ||
633 imm_type == RTRS_IO_RSP_W_INV_IMM) {
634 u32 msg_id;
635
636 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
637 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
638
639 process_io_rsp(clt_path, msg_id, err, w_inval);
640 } else if (imm_type == RTRS_HB_MSG_IMM) {
641 WARN_ON(con->c.cid);
642 rtrs_send_hb_ack(&clt_path->s);
643 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
644 return rtrs_clt_recv_done(con, wc);
645 } else if (imm_type == RTRS_HB_ACK_IMM) {
646 WARN_ON(con->c.cid);
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 clt_path->s.hb_missed_cnt = 0;
674 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE ||
675 wc->wc_flags & IB_WC_WITH_IMM));
676 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done);
677 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
678 if (wc->wc_flags & IB_WC_WITH_INVALIDATE)
679 return rtrs_clt_recv_done(con, wc);
680
681 return rtrs_clt_rkey_rsp_done(con, wc);
682 }
683 break;
684 case IB_WC_RDMA_WRITE:
685 /*
686 * post_send() RDMA write completions of IO reqs (read/write)
687 * and hb.
688 */
689 break;
690
691 default:
692 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode);
693 return;
694 }
695 }
696
post_recv_io(struct rtrs_clt_con * con,size_t q_size)697 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size)
698 {
699 int err, i;
700 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
701
702 for (i = 0; i < q_size; i++) {
703 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
704 struct rtrs_iu *iu = &con->rsp_ius[i];
705
706 err = rtrs_iu_post_recv(&con->c, iu);
707 } else {
708 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
709 }
710 if (err)
711 return err;
712 }
713
714 return 0;
715 }
716
post_recv_path(struct rtrs_clt_path * clt_path)717 static int post_recv_path(struct rtrs_clt_path *clt_path)
718 {
719 size_t q_size = 0;
720 int err, cid;
721
722 for (cid = 0; cid < clt_path->s.con_num; cid++) {
723 if (cid == 0)
724 q_size = SERVICE_CON_QUEUE_DEPTH;
725 else
726 q_size = clt_path->queue_depth;
727
728 /*
729 * x2 for RDMA read responses + FR key invalidations,
730 * RDMA writes do not require any FR registrations.
731 */
732 q_size *= 2;
733
734 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size);
735 if (err) {
736 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n",
737 err);
738 return err;
739 }
740 }
741
742 return 0;
743 }
744
745 struct path_it {
746 int i;
747 struct list_head skip_list;
748 struct rtrs_clt_sess *clt;
749 struct rtrs_clt_path *(*next_path)(struct path_it *it);
750 };
751
752 /*
753 * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL
754 * @head: the head for the list.
755 * @clt_path: The element to take the next clt_path from.
756 *
757 * Next clt path returned in round-robin fashion, i.e. head will be skipped,
758 * but if list is observed as empty, NULL will be returned.
759 *
760 * This function may safely run concurrently with the _rcu list-mutation
761 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
762 */
763 static inline struct rtrs_clt_path *
rtrs_clt_get_next_path_or_null(struct list_head * head,struct rtrs_clt_path * clt_path)764 rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path)
765 {
766 return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?:
767 list_next_or_null_rcu(head,
768 READ_ONCE((&clt_path->s.entry)->next),
769 typeof(*clt_path), s.entry);
770 }
771
772 /**
773 * get_next_path_rr() - Returns path in round-robin fashion.
774 * @it: the path pointer
775 *
776 * Related to @MP_POLICY_RR
777 *
778 * Locks:
779 * rcu_read_lock() must be hold.
780 */
get_next_path_rr(struct path_it * it)781 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it)
782 {
783 struct rtrs_clt_path __rcu **ppcpu_path;
784 struct rtrs_clt_path *path;
785 struct rtrs_clt_sess *clt;
786
787 clt = it->clt;
788
789 /*
790 * Here we use two RCU objects: @paths_list and @pcpu_path
791 * pointer. See rtrs_clt_remove_path_from_arr() for details
792 * how that is handled.
793 */
794
795 ppcpu_path = this_cpu_ptr(clt->pcpu_path);
796 path = rcu_dereference(*ppcpu_path);
797 if (!path)
798 path = list_first_or_null_rcu(&clt->paths_list,
799 typeof(*path), s.entry);
800 else
801 path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path);
802
803 rcu_assign_pointer(*ppcpu_path, path);
804
805 return path;
806 }
807
808 /**
809 * get_next_path_min_inflight() - Returns path with minimal inflight count.
810 * @it: the path pointer
811 *
812 * Related to @MP_POLICY_MIN_INFLIGHT
813 *
814 * Locks:
815 * rcu_read_lock() must be hold.
816 */
get_next_path_min_inflight(struct path_it * it)817 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it)
818 {
819 struct rtrs_clt_path *min_path = NULL;
820 struct rtrs_clt_sess *clt = it->clt;
821 struct rtrs_clt_path *clt_path;
822 int min_inflight = INT_MAX;
823 int inflight;
824
825 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
826 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
827 continue;
828
829 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
830 continue;
831
832 inflight = atomic_read(&clt_path->stats->inflight);
833
834 if (inflight < min_inflight) {
835 min_inflight = inflight;
836 min_path = clt_path;
837 }
838 }
839
840 /*
841 * add the path to the skip list, so that next time we can get
842 * a different one
843 */
844 if (min_path)
845 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
846
847 return min_path;
848 }
849
850 /**
851 * get_next_path_min_latency() - Returns path with minimal latency.
852 * @it: the path pointer
853 *
854 * Return: a path with the lowest latency or NULL if all paths are tried
855 *
856 * Locks:
857 * rcu_read_lock() must be hold.
858 *
859 * Related to @MP_POLICY_MIN_LATENCY
860 *
861 * This DOES skip an already-tried path.
862 * There is a skip-list to skip a path if the path has tried but failed.
863 * It will try the minimum latency path and then the second minimum latency
864 * path and so on. Finally it will return NULL if all paths are tried.
865 * Therefore the caller MUST check the returned
866 * path is NULL and trigger the IO error.
867 */
get_next_path_min_latency(struct path_it * it)868 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it)
869 {
870 struct rtrs_clt_path *min_path = NULL;
871 struct rtrs_clt_sess *clt = it->clt;
872 struct rtrs_clt_path *clt_path;
873 ktime_t min_latency = KTIME_MAX;
874 ktime_t latency;
875
876 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
877 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
878 continue;
879
880 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
881 continue;
882
883 latency = clt_path->s.hb_cur_latency;
884
885 if (latency < min_latency) {
886 min_latency = latency;
887 min_path = clt_path;
888 }
889 }
890
891 /*
892 * add the path to the skip list, so that next time we can get
893 * a different one
894 */
895 if (min_path)
896 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
897
898 return min_path;
899 }
900
path_it_init(struct path_it * it,struct rtrs_clt_sess * clt)901 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt)
902 {
903 INIT_LIST_HEAD(&it->skip_list);
904 it->clt = clt;
905 it->i = 0;
906
907 if (clt->mp_policy == MP_POLICY_RR)
908 it->next_path = get_next_path_rr;
909 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
910 it->next_path = get_next_path_min_inflight;
911 else
912 it->next_path = get_next_path_min_latency;
913 }
914
path_it_deinit(struct path_it * it)915 static inline void path_it_deinit(struct path_it *it)
916 {
917 struct list_head *skip, *tmp;
918 /*
919 * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies.
920 * We need to remove paths from it, so that next IO can insert
921 * paths (->mp_skip_entry) into a skip_list again.
922 */
923 list_for_each_safe(skip, tmp, &it->skip_list)
924 list_del_init(skip);
925 }
926
927 /**
928 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information
929 * about an inflight IO.
930 * The user buffer holding user control message (not data) is copied into
931 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will
932 * also hold the control message of rtrs.
933 * @req: an io request holding information about IO.
934 * @clt_path: client path
935 * @conf: conformation callback function to notify upper layer.
936 * @permit: permit for allocation of RDMA remote buffer
937 * @priv: private pointer
938 * @vec: kernel vector containing control message
939 * @usr_len: length of the user message
940 * @sg: scater list for IO data
941 * @sg_cnt: number of scater list entries
942 * @data_len: length of the IO data
943 * @dir: direction of the IO.
944 */
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)945 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
946 struct rtrs_clt_path *clt_path,
947 void (*conf)(void *priv, int errno),
948 struct rtrs_permit *permit, void *priv,
949 const struct kvec *vec, size_t usr_len,
950 struct scatterlist *sg, size_t sg_cnt,
951 size_t data_len, int dir)
952 {
953 struct iov_iter iter;
954 size_t len;
955
956 req->permit = permit;
957 req->in_use = true;
958 req->usr_len = usr_len;
959 req->data_len = data_len;
960 req->sglist = sg;
961 req->sg_cnt = sg_cnt;
962 req->priv = priv;
963 req->dir = dir;
964 req->con = rtrs_permit_to_clt_con(clt_path, permit);
965 req->conf = conf;
966 req->need_inv = false;
967 req->need_inv_comp = false;
968 req->inv_errno = 0;
969 refcount_set(&req->ref, 1);
970 req->mp_policy = clt_path->clt->mp_policy;
971
972 iov_iter_kvec(&iter, ITER_SOURCE, vec, 1, usr_len);
973 len = _copy_from_iter(req->iu->buf, usr_len, &iter);
974 WARN_ON(len != usr_len);
975
976 reinit_completion(&req->inv_comp);
977 }
978
979 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)980 rtrs_clt_get_req(struct rtrs_clt_path *clt_path,
981 void (*conf)(void *priv, int errno),
982 struct rtrs_permit *permit, void *priv,
983 const struct kvec *vec, size_t usr_len,
984 struct scatterlist *sg, size_t sg_cnt,
985 size_t data_len, int dir)
986 {
987 struct rtrs_clt_io_req *req;
988
989 req = &clt_path->reqs[permit->mem_id];
990 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len,
991 sg, sg_cnt, data_len, dir);
992 return req;
993 }
994
995 static struct rtrs_clt_io_req *
rtrs_clt_get_copy_req(struct rtrs_clt_path * alive_path,struct rtrs_clt_io_req * fail_req)996 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path,
997 struct rtrs_clt_io_req *fail_req)
998 {
999 struct rtrs_clt_io_req *req;
1000 struct kvec vec = {
1001 .iov_base = fail_req->iu->buf,
1002 .iov_len = fail_req->usr_len
1003 };
1004
1005 req = &alive_path->reqs[fail_req->permit->mem_id];
1006 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit,
1007 fail_req->priv, &vec, fail_req->usr_len,
1008 fail_req->sglist, fail_req->sg_cnt,
1009 fail_req->data_len, fail_req->dir);
1010 return req;
1011 }
1012
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)1013 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
1014 struct rtrs_clt_io_req *req,
1015 struct rtrs_rbuf *rbuf, bool fr_en,
1016 u32 count, u32 size, u32 imm,
1017 struct ib_send_wr *wr,
1018 struct ib_send_wr *tail)
1019 {
1020 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1021 struct ib_sge *sge = req->sge;
1022 enum ib_send_flags flags;
1023 struct scatterlist *sg;
1024 size_t num_sge;
1025 int i;
1026 struct ib_send_wr *ptail = NULL;
1027
1028 if (fr_en) {
1029 i = 0;
1030 sge[i].addr = req->mr->iova;
1031 sge[i].length = req->mr->length;
1032 sge[i].lkey = req->mr->lkey;
1033 i++;
1034 num_sge = 2;
1035 ptail = tail;
1036 } else {
1037 for_each_sg(req->sglist, sg, count, i) {
1038 sge[i].addr = sg_dma_address(sg);
1039 sge[i].length = sg_dma_len(sg);
1040 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
1041 }
1042 num_sge = 1 + count;
1043 }
1044 sge[i].addr = req->iu->dma_addr;
1045 sge[i].length = size;
1046 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
1047
1048 /*
1049 * From time to time we have to post signalled sends,
1050 * or send queue will fill up and only QP reset can help.
1051 */
1052 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
1053 0 : IB_SEND_SIGNALED;
1054
1055 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
1056 req->iu->dma_addr,
1057 size, DMA_TO_DEVICE);
1058
1059 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
1060 rbuf->rkey, rbuf->addr, imm,
1061 flags, wr, ptail);
1062 }
1063
rtrs_map_sg_fr(struct rtrs_clt_io_req * req,size_t count)1064 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
1065 {
1066 int nr;
1067
1068 /* Align the MR to a 4K page size to match the block virt boundary */
1069 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
1070 if (nr != count)
1071 return nr < 0 ? nr : -EINVAL;
1072 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
1073
1074 return nr;
1075 }
1076
rtrs_clt_write_req(struct rtrs_clt_io_req * req)1077 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
1078 {
1079 struct rtrs_clt_con *con = req->con;
1080 struct rtrs_path *s = con->c.path;
1081 struct rtrs_clt_path *clt_path = to_clt_path(s);
1082 struct rtrs_msg_rdma_write *msg;
1083
1084 struct rtrs_rbuf *rbuf;
1085 int ret, count = 0;
1086 u32 imm, buf_id;
1087 struct ib_reg_wr rwr;
1088 struct ib_send_wr inv_wr;
1089 struct ib_send_wr *wr = NULL;
1090 bool fr_en = false;
1091
1092 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
1093
1094 if (tsize > clt_path->chunk_size) {
1095 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n",
1096 tsize, clt_path->chunk_size);
1097 return -EMSGSIZE;
1098 }
1099 if (req->sg_cnt) {
1100 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist,
1101 req->sg_cnt, req->dir);
1102 if (!count) {
1103 rtrs_wrn(s, "Write request failed, map failed\n");
1104 return -EINVAL;
1105 }
1106 }
1107 /* put rtrs msg after sg and user message */
1108 msg = req->iu->buf + req->usr_len;
1109 msg->type = cpu_to_le16(RTRS_MSG_WRITE);
1110 msg->usr_len = cpu_to_le16(req->usr_len);
1111
1112 /* rtrs message on server side will be after user data and message */
1113 imm = req->permit->mem_off + req->data_len + req->usr_len;
1114 imm = rtrs_to_io_req_imm(imm);
1115 buf_id = req->permit->mem_id;
1116 req->sg_size = tsize;
1117 rbuf = &clt_path->rbufs[buf_id];
1118
1119 if (count) {
1120 ret = rtrs_map_sg_fr(req, count);
1121 if (ret < 0) {
1122 rtrs_err_rl(s,
1123 "Write request failed, failed to map fast reg. data, err: %d\n",
1124 ret);
1125 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
1126 req->sg_cnt, req->dir);
1127 return ret;
1128 }
1129 inv_wr = (struct ib_send_wr) {
1130 .opcode = IB_WR_LOCAL_INV,
1131 .wr_cqe = &req->inv_cqe,
1132 .send_flags = IB_SEND_SIGNALED,
1133 .ex.invalidate_rkey = req->mr->rkey,
1134 };
1135 req->inv_cqe.done = rtrs_clt_inv_rkey_done;
1136 rwr = (struct ib_reg_wr) {
1137 .wr.opcode = IB_WR_REG_MR,
1138 .wr.wr_cqe = &fast_reg_cqe,
1139 .mr = req->mr,
1140 .key = req->mr->rkey,
1141 .access = (IB_ACCESS_LOCAL_WRITE),
1142 };
1143 wr = &rwr.wr;
1144 fr_en = true;
1145 refcount_inc(&req->ref);
1146 }
1147 /*
1148 * Update stats now, after request is successfully sent it is not
1149 * safe anymore to touch it.
1150 */
1151 rtrs_clt_update_all_stats(req, WRITE);
1152
1153 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count,
1154 req->usr_len + sizeof(*msg),
1155 imm, wr, &inv_wr);
1156 if (ret) {
1157 rtrs_err_rl(s,
1158 "Write request failed: error=%d path=%s [%s:%u]\n",
1159 ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
1160 clt_path->hca_port);
1161 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
1162 atomic_dec(&clt_path->stats->inflight);
1163 if (req->sg_cnt)
1164 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
1165 req->sg_cnt, req->dir);
1166 }
1167
1168 return ret;
1169 }
1170
rtrs_clt_read_req(struct rtrs_clt_io_req * req)1171 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req)
1172 {
1173 struct rtrs_clt_con *con = req->con;
1174 struct rtrs_path *s = con->c.path;
1175 struct rtrs_clt_path *clt_path = to_clt_path(s);
1176 struct rtrs_msg_rdma_read *msg;
1177 struct rtrs_ib_dev *dev = clt_path->s.dev;
1178
1179 struct ib_reg_wr rwr;
1180 struct ib_send_wr *wr = NULL;
1181
1182 int ret, count = 0;
1183 u32 imm, buf_id;
1184
1185 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
1186
1187 if (tsize > clt_path->chunk_size) {
1188 rtrs_wrn(s,
1189 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n",
1190 tsize, clt_path->chunk_size);
1191 return -EMSGSIZE;
1192 }
1193
1194 if (req->sg_cnt) {
1195 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt,
1196 req->dir);
1197 if (!count) {
1198 rtrs_wrn(s,
1199 "Read request failed, dma map failed\n");
1200 return -EINVAL;
1201 }
1202 }
1203 /* put our message into req->buf after user message*/
1204 msg = req->iu->buf + req->usr_len;
1205 msg->type = cpu_to_le16(RTRS_MSG_READ);
1206 msg->usr_len = cpu_to_le16(req->usr_len);
1207
1208 if (count) {
1209 ret = rtrs_map_sg_fr(req, count);
1210 if (ret < 0) {
1211 rtrs_err_rl(s,
1212 "Read request failed, failed to map fast reg. data, err: %d\n",
1213 ret);
1214 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt,
1215 req->dir);
1216 return ret;
1217 }
1218 rwr = (struct ib_reg_wr) {
1219 .wr.opcode = IB_WR_REG_MR,
1220 .wr.wr_cqe = &fast_reg_cqe,
1221 .mr = req->mr,
1222 .key = req->mr->rkey,
1223 .access = (IB_ACCESS_LOCAL_WRITE |
1224 IB_ACCESS_REMOTE_WRITE),
1225 };
1226 wr = &rwr.wr;
1227
1228 msg->sg_cnt = cpu_to_le16(1);
1229 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F);
1230
1231 msg->desc[0].addr = cpu_to_le64(req->mr->iova);
1232 msg->desc[0].key = cpu_to_le32(req->mr->rkey);
1233 msg->desc[0].len = cpu_to_le32(req->mr->length);
1234
1235 /* Further invalidation is required */
1236 req->need_inv = !!RTRS_MSG_NEED_INVAL_F;
1237
1238 } else {
1239 msg->sg_cnt = 0;
1240 msg->flags = 0;
1241 }
1242 /*
1243 * rtrs message will be after the space reserved for disk data and
1244 * user message
1245 */
1246 imm = req->permit->mem_off + req->data_len + req->usr_len;
1247 imm = rtrs_to_io_req_imm(imm);
1248 buf_id = req->permit->mem_id;
1249
1250 req->sg_size = sizeof(*msg);
1251 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc);
1252 req->sg_size += req->usr_len;
1253
1254 /*
1255 * Update stats now, after request is successfully sent it is not
1256 * safe anymore to touch it.
1257 */
1258 rtrs_clt_update_all_stats(req, READ);
1259
1260 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id],
1261 req->data_len, imm, wr);
1262 if (ret) {
1263 rtrs_err_rl(s,
1264 "Read request failed: error=%d path=%s [%s:%u]\n",
1265 ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
1266 clt_path->hca_port);
1267 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
1268 atomic_dec(&clt_path->stats->inflight);
1269 req->need_inv = false;
1270 if (req->sg_cnt)
1271 ib_dma_unmap_sg(dev->ib_dev, req->sglist,
1272 req->sg_cnt, req->dir);
1273 }
1274
1275 return ret;
1276 }
1277
1278 /**
1279 * rtrs_clt_failover_req() - Try to find an active path for a failed request
1280 * @clt: clt context
1281 * @fail_req: a failed io request.
1282 */
rtrs_clt_failover_req(struct rtrs_clt_sess * clt,struct rtrs_clt_io_req * fail_req)1283 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt,
1284 struct rtrs_clt_io_req *fail_req)
1285 {
1286 struct rtrs_clt_path *alive_path;
1287 struct rtrs_clt_io_req *req;
1288 int err = -ECONNABORTED;
1289 struct path_it it;
1290
1291 rcu_read_lock();
1292 for (path_it_init(&it, clt);
1293 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num;
1294 it.i++) {
1295 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED)
1296 continue;
1297 req = rtrs_clt_get_copy_req(alive_path, fail_req);
1298 if (req->dir == DMA_TO_DEVICE)
1299 err = rtrs_clt_write_req(req);
1300 else
1301 err = rtrs_clt_read_req(req);
1302 if (err) {
1303 req->in_use = false;
1304 continue;
1305 }
1306 /* Success path */
1307 rtrs_clt_inc_failover_cnt(alive_path->stats);
1308 break;
1309 }
1310 path_it_deinit(&it);
1311 rcu_read_unlock();
1312
1313 return err;
1314 }
1315
fail_all_outstanding_reqs(struct rtrs_clt_path * clt_path)1316 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path)
1317 {
1318 struct rtrs_clt_sess *clt = clt_path->clt;
1319 struct rtrs_clt_io_req *req;
1320 int i, err;
1321
1322 if (!clt_path->reqs)
1323 return;
1324 for (i = 0; i < clt_path->queue_depth; ++i) {
1325 req = &clt_path->reqs[i];
1326 if (!req->in_use)
1327 continue;
1328
1329 /*
1330 * Safely (without notification) complete failed request.
1331 * After completion this request is still useble and can
1332 * be failovered to another path.
1333 */
1334 complete_rdma_req(req, -ECONNABORTED, false, true);
1335
1336 err = rtrs_clt_failover_req(clt, req);
1337 if (err)
1338 /* Failover failed, notify anyway */
1339 req->conf(req->priv, err);
1340 }
1341 }
1342
free_path_reqs(struct rtrs_clt_path * clt_path)1343 static void free_path_reqs(struct rtrs_clt_path *clt_path)
1344 {
1345 struct rtrs_clt_io_req *req;
1346 int i;
1347
1348 if (!clt_path->reqs)
1349 return;
1350 for (i = 0; i < clt_path->queue_depth; ++i) {
1351 req = &clt_path->reqs[i];
1352 if (req->mr)
1353 ib_dereg_mr(req->mr);
1354 kfree(req->sge);
1355 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1);
1356 }
1357 kfree(clt_path->reqs);
1358 clt_path->reqs = NULL;
1359 }
1360
alloc_path_reqs(struct rtrs_clt_path * clt_path)1361 static int alloc_path_reqs(struct rtrs_clt_path *clt_path)
1362 {
1363 struct rtrs_clt_io_req *req;
1364 int i, err = -ENOMEM;
1365
1366 clt_path->reqs = kcalloc(clt_path->queue_depth,
1367 sizeof(*clt_path->reqs),
1368 GFP_KERNEL);
1369 if (!clt_path->reqs)
1370 return -ENOMEM;
1371
1372 for (i = 0; i < clt_path->queue_depth; ++i) {
1373 req = &clt_path->reqs[i];
1374 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL,
1375 clt_path->s.dev->ib_dev,
1376 DMA_TO_DEVICE,
1377 rtrs_clt_rdma_done);
1378 if (!req->iu)
1379 goto out;
1380
1381 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL);
1382 if (!req->sge)
1383 goto out;
1384
1385 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd,
1386 IB_MR_TYPE_MEM_REG,
1387 clt_path->max_pages_per_mr);
1388 if (IS_ERR(req->mr)) {
1389 err = PTR_ERR(req->mr);
1390 req->mr = NULL;
1391 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n",
1392 clt_path->max_pages_per_mr);
1393 goto out;
1394 }
1395
1396 init_completion(&req->inv_comp);
1397 }
1398
1399 return 0;
1400
1401 out:
1402 free_path_reqs(clt_path);
1403
1404 return err;
1405 }
1406
alloc_permits(struct rtrs_clt_sess * clt)1407 static int alloc_permits(struct rtrs_clt_sess *clt)
1408 {
1409 unsigned int chunk_bits;
1410 int err, i;
1411
1412 clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL);
1413 if (!clt->permits_map) {
1414 err = -ENOMEM;
1415 goto out_err;
1416 }
1417 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL);
1418 if (!clt->permits) {
1419 err = -ENOMEM;
1420 goto err_map;
1421 }
1422 chunk_bits = ilog2(clt->queue_depth - 1) + 1;
1423 for (i = 0; i < clt->queue_depth; i++) {
1424 struct rtrs_permit *permit;
1425
1426 permit = get_permit(clt, i);
1427 permit->mem_id = i;
1428 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits);
1429 }
1430
1431 return 0;
1432
1433 err_map:
1434 bitmap_free(clt->permits_map);
1435 clt->permits_map = NULL;
1436 out_err:
1437 return err;
1438 }
1439
free_permits(struct rtrs_clt_sess * clt)1440 static void free_permits(struct rtrs_clt_sess *clt)
1441 {
1442 if (clt->permits_map)
1443 wait_event(clt->permits_wait,
1444 bitmap_empty(clt->permits_map, clt->queue_depth));
1445
1446 bitmap_free(clt->permits_map);
1447 clt->permits_map = NULL;
1448 kfree(clt->permits);
1449 clt->permits = NULL;
1450 }
1451
query_fast_reg_mode(struct rtrs_clt_path * clt_path)1452 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path)
1453 {
1454 struct ib_device *ib_dev;
1455 u64 max_pages_per_mr;
1456 int mr_page_shift;
1457
1458 ib_dev = clt_path->s.dev->ib_dev;
1459
1460 /*
1461 * Use the smallest page size supported by the HCA, down to a
1462 * minimum of 4096 bytes. We're unlikely to build large sglists
1463 * out of smaller entries.
1464 */
1465 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1);
1466 max_pages_per_mr = ib_dev->attrs.max_mr_size;
1467 do_div(max_pages_per_mr, (1ull << mr_page_shift));
1468 clt_path->max_pages_per_mr =
1469 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr,
1470 ib_dev->attrs.max_fast_reg_page_list_len);
1471 clt_path->clt->max_segments =
1472 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments);
1473 }
1474
rtrs_clt_change_state_get_old(struct rtrs_clt_path * clt_path,enum rtrs_clt_state new_state,enum rtrs_clt_state * old_state)1475 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path,
1476 enum rtrs_clt_state new_state,
1477 enum rtrs_clt_state *old_state)
1478 {
1479 bool changed;
1480
1481 spin_lock_irq(&clt_path->state_wq.lock);
1482 if (old_state)
1483 *old_state = clt_path->state;
1484 changed = rtrs_clt_change_state(clt_path, new_state);
1485 spin_unlock_irq(&clt_path->state_wq.lock);
1486
1487 return changed;
1488 }
1489
rtrs_clt_hb_err_handler(struct rtrs_con * c)1490 static void rtrs_clt_hb_err_handler(struct rtrs_con *c)
1491 {
1492 struct rtrs_clt_con *con = container_of(c, typeof(*con), c);
1493
1494 rtrs_rdma_error_recovery(con);
1495 }
1496
rtrs_clt_init_hb(struct rtrs_clt_path * clt_path)1497 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path)
1498 {
1499 rtrs_init_hb(&clt_path->s, &io_comp_cqe,
1500 RTRS_HB_INTERVAL_MS,
1501 RTRS_HB_MISSED_MAX,
1502 rtrs_clt_hb_err_handler,
1503 rtrs_wq);
1504 }
1505
1506 static void rtrs_clt_reconnect_work(struct work_struct *work);
1507 static void rtrs_clt_close_work(struct work_struct *work);
1508
rtrs_clt_err_recovery_work(struct work_struct * work)1509 static void rtrs_clt_err_recovery_work(struct work_struct *work)
1510 {
1511 struct rtrs_clt_path *clt_path;
1512 struct rtrs_clt_sess *clt;
1513 int delay_ms;
1514
1515 clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work);
1516 clt = clt_path->clt;
1517 delay_ms = clt->reconnect_delay_sec * 1000;
1518 rtrs_clt_stop_and_destroy_conns(clt_path);
1519 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
1520 msecs_to_jiffies(delay_ms +
1521 get_random_u32_below(RTRS_RECONNECT_SEED)));
1522 }
1523
alloc_path(struct rtrs_clt_sess * clt,const struct rtrs_addr * path,size_t con_num,u32 nr_poll_queues)1524 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
1525 const struct rtrs_addr *path,
1526 size_t con_num, u32 nr_poll_queues)
1527 {
1528 struct rtrs_clt_path *clt_path;
1529 int err = -ENOMEM;
1530 int cpu;
1531 size_t total_con;
1532
1533 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL);
1534 if (!clt_path)
1535 goto err;
1536
1537 /*
1538 * irqmode and poll
1539 * +1: Extra connection for user messages
1540 */
1541 total_con = con_num + nr_poll_queues + 1;
1542 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con),
1543 GFP_KERNEL);
1544 if (!clt_path->s.con)
1545 goto err_free_path;
1546
1547 clt_path->s.con_num = total_con;
1548 clt_path->s.irq_con_num = con_num + 1;
1549
1550 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL);
1551 if (!clt_path->stats)
1552 goto err_free_con;
1553
1554 mutex_init(&clt_path->init_mutex);
1555 uuid_gen(&clt_path->s.uuid);
1556 memcpy(&clt_path->s.dst_addr, path->dst,
1557 rdma_addr_size((struct sockaddr *)path->dst));
1558
1559 /*
1560 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which
1561 * checks the sa_family to be non-zero. If user passed src_addr=NULL
1562 * the sess->src_addr will contain only zeros, which is then fine.
1563 */
1564 if (path->src)
1565 memcpy(&clt_path->s.src_addr, path->src,
1566 rdma_addr_size((struct sockaddr *)path->src));
1567 strscpy(clt_path->s.sessname, clt->sessname,
1568 sizeof(clt_path->s.sessname));
1569 clt_path->clt = clt;
1570 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS;
1571 init_waitqueue_head(&clt_path->state_wq);
1572 clt_path->state = RTRS_CLT_CONNECTING;
1573 atomic_set(&clt_path->connected_cnt, 0);
1574 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work);
1575 INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work);
1576 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work);
1577 rtrs_clt_init_hb(clt_path);
1578
1579 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry));
1580 if (!clt_path->mp_skip_entry)
1581 goto err_free_stats;
1582
1583 for_each_possible_cpu(cpu)
1584 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu));
1585
1586 err = rtrs_clt_init_stats(clt_path->stats);
1587 if (err)
1588 goto err_free_percpu;
1589
1590 return clt_path;
1591
1592 err_free_percpu:
1593 free_percpu(clt_path->mp_skip_entry);
1594 err_free_stats:
1595 kfree(clt_path->stats);
1596 err_free_con:
1597 kfree(clt_path->s.con);
1598 err_free_path:
1599 kfree(clt_path);
1600 err:
1601 return ERR_PTR(err);
1602 }
1603
free_path(struct rtrs_clt_path * clt_path)1604 void free_path(struct rtrs_clt_path *clt_path)
1605 {
1606 free_percpu(clt_path->mp_skip_entry);
1607 mutex_destroy(&clt_path->init_mutex);
1608 kfree(clt_path->s.con);
1609 kfree(clt_path->rbufs);
1610 kfree(clt_path);
1611 }
1612
create_con(struct rtrs_clt_path * clt_path,unsigned int cid)1613 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid)
1614 {
1615 struct rtrs_clt_con *con;
1616
1617 con = kzalloc(sizeof(*con), GFP_KERNEL);
1618 if (!con)
1619 return -ENOMEM;
1620
1621 /* Map first two connections to the first CPU */
1622 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids;
1623 con->c.cid = cid;
1624 con->c.path = &clt_path->s;
1625 /* Align with srv, init as 1 */
1626 atomic_set(&con->c.wr_cnt, 1);
1627 mutex_init(&con->con_mutex);
1628
1629 clt_path->s.con[cid] = &con->c;
1630
1631 return 0;
1632 }
1633
destroy_con(struct rtrs_clt_con * con)1634 static void destroy_con(struct rtrs_clt_con *con)
1635 {
1636 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1637
1638 clt_path->s.con[con->c.cid] = NULL;
1639 mutex_destroy(&con->con_mutex);
1640 kfree(con);
1641 }
1642
create_con_cq_qp(struct rtrs_clt_con * con)1643 static int create_con_cq_qp(struct rtrs_clt_con *con)
1644 {
1645 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1646 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit;
1647 int err, cq_vector;
1648 struct rtrs_msg_rkey_rsp *rsp;
1649
1650 lockdep_assert_held(&con->con_mutex);
1651 if (con->c.cid == 0) {
1652 max_send_sge = 1;
1653 /* We must be the first here */
1654 if (WARN_ON(clt_path->s.dev))
1655 return -EINVAL;
1656
1657 /*
1658 * The whole session uses device from user connection.
1659 * Be careful not to close user connection before ib dev
1660 * is gracefully put.
1661 */
1662 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device,
1663 &dev_pd);
1664 if (!clt_path->s.dev) {
1665 rtrs_wrn(clt_path->clt,
1666 "rtrs_ib_dev_find_get_or_add(): no memory\n");
1667 return -ENOMEM;
1668 }
1669 clt_path->s.dev_ref = 1;
1670 query_fast_reg_mode(clt_path);
1671 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
1672 /*
1673 * Two (request + registration) completion for send
1674 * Two for recv if always_invalidate is set on server
1675 * or one for recv.
1676 * + 2 for drain and heartbeat
1677 * in case qp gets into error state.
1678 */
1679 max_send_wr =
1680 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2);
1681 max_recv_wr = max_send_wr;
1682 } else {
1683 /*
1684 * Here we assume that session members are correctly set.
1685 * This is always true if user connection (cid == 0) is
1686 * established first.
1687 */
1688 if (WARN_ON(!clt_path->s.dev))
1689 return -EINVAL;
1690 if (WARN_ON(!clt_path->queue_depth))
1691 return -EINVAL;
1692
1693 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
1694 /* Shared between connections */
1695 clt_path->s.dev_ref++;
1696 max_send_wr = min_t(int, wr_limit,
1697 /* QD * (REQ + RSP + FR REGS or INVS) + drain */
1698 clt_path->queue_depth * 4 + 1);
1699 max_recv_wr = min_t(int, wr_limit,
1700 clt_path->queue_depth * 3 + 1);
1701 max_send_sge = 2;
1702 }
1703 atomic_set(&con->c.sq_wr_avail, max_send_wr);
1704 cq_num = max_send_wr + max_recv_wr;
1705 /* alloc iu to recv new rkey reply when server reports flags set */
1706 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
1707 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp),
1708 GFP_KERNEL,
1709 clt_path->s.dev->ib_dev,
1710 DMA_FROM_DEVICE,
1711 rtrs_clt_rdma_done);
1712 if (!con->rsp_ius)
1713 return -ENOMEM;
1714 con->queue_num = cq_num;
1715 }
1716 cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors;
1717 if (con->c.cid >= clt_path->s.irq_con_num)
1718 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge,
1719 cq_vector, cq_num, max_send_wr,
1720 max_recv_wr, IB_POLL_DIRECT);
1721 else
1722 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge,
1723 cq_vector, cq_num, max_send_wr,
1724 max_recv_wr, IB_POLL_SOFTIRQ);
1725 /*
1726 * In case of error we do not bother to clean previous allocations,
1727 * since destroy_con_cq_qp() must be called.
1728 */
1729 return err;
1730 }
1731
destroy_con_cq_qp(struct rtrs_clt_con * con)1732 static void destroy_con_cq_qp(struct rtrs_clt_con *con)
1733 {
1734 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1735
1736 /*
1737 * Be careful here: destroy_con_cq_qp() can be called even
1738 * create_con_cq_qp() failed, see comments there.
1739 */
1740 lockdep_assert_held(&con->con_mutex);
1741 rtrs_cq_qp_destroy(&con->c);
1742 if (con->rsp_ius) {
1743 rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev,
1744 con->queue_num);
1745 con->rsp_ius = NULL;
1746 con->queue_num = 0;
1747 }
1748 if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) {
1749 rtrs_ib_dev_put(clt_path->s.dev);
1750 clt_path->s.dev = NULL;
1751 }
1752 }
1753
stop_cm(struct rtrs_clt_con * con)1754 static void stop_cm(struct rtrs_clt_con *con)
1755 {
1756 rdma_disconnect(con->c.cm_id);
1757 if (con->c.qp)
1758 ib_drain_qp(con->c.qp);
1759 }
1760
destroy_cm(struct rtrs_clt_con * con)1761 static void destroy_cm(struct rtrs_clt_con *con)
1762 {
1763 rdma_destroy_id(con->c.cm_id);
1764 con->c.cm_id = NULL;
1765 }
1766
rtrs_rdma_addr_resolved(struct rtrs_clt_con * con)1767 static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con)
1768 {
1769 struct rtrs_path *s = con->c.path;
1770 int err;
1771
1772 mutex_lock(&con->con_mutex);
1773 err = create_con_cq_qp(con);
1774 mutex_unlock(&con->con_mutex);
1775 if (err) {
1776 rtrs_err(s, "create_con_cq_qp(), err: %d\n", err);
1777 return err;
1778 }
1779 err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS);
1780 if (err)
1781 rtrs_err(s, "Resolving route failed, err: %d\n", err);
1782
1783 return err;
1784 }
1785
rtrs_rdma_route_resolved(struct rtrs_clt_con * con)1786 static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con)
1787 {
1788 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1789 struct rtrs_clt_sess *clt = clt_path->clt;
1790 struct rtrs_msg_conn_req msg;
1791 struct rdma_conn_param param;
1792
1793 int err;
1794
1795 param = (struct rdma_conn_param) {
1796 .retry_count = 7,
1797 .rnr_retry_count = 7,
1798 .private_data = &msg,
1799 .private_data_len = sizeof(msg),
1800 };
1801
1802 msg = (struct rtrs_msg_conn_req) {
1803 .magic = cpu_to_le16(RTRS_MAGIC),
1804 .version = cpu_to_le16(RTRS_PROTO_VER),
1805 .cid = cpu_to_le16(con->c.cid),
1806 .cid_num = cpu_to_le16(clt_path->s.con_num),
1807 .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt),
1808 };
1809 msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0;
1810 uuid_copy(&msg.sess_uuid, &clt_path->s.uuid);
1811 uuid_copy(&msg.paths_uuid, &clt->paths_uuid);
1812
1813 err = rdma_connect_locked(con->c.cm_id, ¶m);
1814 if (err)
1815 rtrs_err(clt, "rdma_connect_locked(): %d\n", err);
1816
1817 return err;
1818 }
1819
rtrs_rdma_conn_established(struct rtrs_clt_con * con,struct rdma_cm_event * ev)1820 static int rtrs_rdma_conn_established(struct rtrs_clt_con *con,
1821 struct rdma_cm_event *ev)
1822 {
1823 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1824 struct rtrs_clt_sess *clt = clt_path->clt;
1825 const struct rtrs_msg_conn_rsp *msg;
1826 u16 version, queue_depth;
1827 int errno;
1828 u8 len;
1829
1830 msg = ev->param.conn.private_data;
1831 len = ev->param.conn.private_data_len;
1832 if (len < sizeof(*msg)) {
1833 rtrs_err(clt, "Invalid RTRS connection response\n");
1834 return -ECONNRESET;
1835 }
1836 if (le16_to_cpu(msg->magic) != RTRS_MAGIC) {
1837 rtrs_err(clt, "Invalid RTRS magic\n");
1838 return -ECONNRESET;
1839 }
1840 version = le16_to_cpu(msg->version);
1841 if (version >> 8 != RTRS_PROTO_VER_MAJOR) {
1842 rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n",
1843 version >> 8, RTRS_PROTO_VER_MAJOR);
1844 return -ECONNRESET;
1845 }
1846 errno = le16_to_cpu(msg->errno);
1847 if (errno) {
1848 rtrs_err(clt, "Invalid RTRS message: errno %d\n",
1849 errno);
1850 return -ECONNRESET;
1851 }
1852 if (con->c.cid == 0) {
1853 queue_depth = le16_to_cpu(msg->queue_depth);
1854
1855 if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) {
1856 rtrs_err(clt, "Error: queue depth changed\n");
1857
1858 /*
1859 * Stop any more reconnection attempts
1860 */
1861 clt_path->reconnect_attempts = -1;
1862 rtrs_err(clt,
1863 "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n");
1864 return -ECONNRESET;
1865 }
1866
1867 if (!clt_path->rbufs) {
1868 clt_path->rbufs = kcalloc(queue_depth,
1869 sizeof(*clt_path->rbufs),
1870 GFP_KERNEL);
1871 if (!clt_path->rbufs)
1872 return -ENOMEM;
1873 }
1874 clt_path->queue_depth = queue_depth;
1875 clt_path->s.signal_interval = min_not_zero(queue_depth,
1876 (unsigned short) SERVICE_CON_QUEUE_DEPTH);
1877 clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size);
1878 clt_path->max_io_size = le32_to_cpu(msg->max_io_size);
1879 clt_path->flags = le32_to_cpu(msg->flags);
1880 clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size;
1881
1882 /*
1883 * Global IO size is always a minimum.
1884 * If while a reconnection server sends us a value a bit
1885 * higher - client does not care and uses cached minimum.
1886 *
1887 * Since we can have several sessions (paths) restablishing
1888 * connections in parallel, use lock.
1889 */
1890 mutex_lock(&clt->paths_mutex);
1891 clt->queue_depth = clt_path->queue_depth;
1892 clt->max_io_size = min_not_zero(clt_path->max_io_size,
1893 clt->max_io_size);
1894 mutex_unlock(&clt->paths_mutex);
1895
1896 /*
1897 * Cache the hca_port and hca_name for sysfs
1898 */
1899 clt_path->hca_port = con->c.cm_id->port_num;
1900 scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name),
1901 clt_path->s.dev->ib_dev->name);
1902 clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr;
1903 /* set for_new_clt, to allow future reconnect on any path */
1904 clt_path->for_new_clt = 1;
1905 }
1906
1907 return 0;
1908 }
1909
flag_success_on_conn(struct rtrs_clt_con * con)1910 static inline void flag_success_on_conn(struct rtrs_clt_con *con)
1911 {
1912 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1913
1914 atomic_inc(&clt_path->connected_cnt);
1915 con->cm_err = 1;
1916 }
1917
rtrs_rdma_conn_rejected(struct rtrs_clt_con * con,struct rdma_cm_event * ev)1918 static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con,
1919 struct rdma_cm_event *ev)
1920 {
1921 struct rtrs_path *s = con->c.path;
1922 const struct rtrs_msg_conn_rsp *msg;
1923 const char *rej_msg;
1924 int status, errno;
1925 u8 data_len;
1926
1927 status = ev->status;
1928 rej_msg = rdma_reject_msg(con->c.cm_id, status);
1929 msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len);
1930
1931 if (msg && data_len >= sizeof(*msg)) {
1932 errno = (int16_t)le16_to_cpu(msg->errno);
1933 if (errno == -EBUSY)
1934 rtrs_err(s,
1935 "Previous session is still exists on the server, please reconnect later\n");
1936 else
1937 rtrs_err(s,
1938 "Connect rejected: status %d (%s), rtrs errno %d\n",
1939 status, rej_msg, errno);
1940 } else {
1941 rtrs_err(s,
1942 "Connect rejected but with malformed message: status %d (%s)\n",
1943 status, rej_msg);
1944 }
1945
1946 return -ECONNRESET;
1947 }
1948
rtrs_clt_close_conns(struct rtrs_clt_path * clt_path,bool wait)1949 void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait)
1950 {
1951 trace_rtrs_clt_close_conns(clt_path);
1952
1953 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL))
1954 queue_work(rtrs_wq, &clt_path->close_work);
1955 if (wait)
1956 flush_work(&clt_path->close_work);
1957 }
1958
flag_error_on_conn(struct rtrs_clt_con * con,int cm_err)1959 static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err)
1960 {
1961 if (con->cm_err == 1) {
1962 struct rtrs_clt_path *clt_path;
1963
1964 clt_path = to_clt_path(con->c.path);
1965 if (atomic_dec_and_test(&clt_path->connected_cnt))
1966
1967 wake_up(&clt_path->state_wq);
1968 }
1969 con->cm_err = cm_err;
1970 }
1971
rtrs_clt_rdma_cm_handler(struct rdma_cm_id * cm_id,struct rdma_cm_event * ev)1972 static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id,
1973 struct rdma_cm_event *ev)
1974 {
1975 struct rtrs_clt_con *con = cm_id->context;
1976 struct rtrs_path *s = con->c.path;
1977 struct rtrs_clt_path *clt_path = to_clt_path(s);
1978 int cm_err = 0;
1979
1980 switch (ev->event) {
1981 case RDMA_CM_EVENT_ADDR_RESOLVED:
1982 cm_err = rtrs_rdma_addr_resolved(con);
1983 break;
1984 case RDMA_CM_EVENT_ROUTE_RESOLVED:
1985 cm_err = rtrs_rdma_route_resolved(con);
1986 break;
1987 case RDMA_CM_EVENT_ESTABLISHED:
1988 cm_err = rtrs_rdma_conn_established(con, ev);
1989 if (!cm_err) {
1990 /*
1991 * Report success and wake up. Here we abuse state_wq,
1992 * i.e. wake up without state change, but we set cm_err.
1993 */
1994 flag_success_on_conn(con);
1995 wake_up(&clt_path->state_wq);
1996 return 0;
1997 }
1998 break;
1999 case RDMA_CM_EVENT_REJECTED:
2000 cm_err = rtrs_rdma_conn_rejected(con, ev);
2001 break;
2002 case RDMA_CM_EVENT_DISCONNECTED:
2003 /* No message for disconnecting */
2004 cm_err = -ECONNRESET;
2005 break;
2006 case RDMA_CM_EVENT_CONNECT_ERROR:
2007 case RDMA_CM_EVENT_UNREACHABLE:
2008 case RDMA_CM_EVENT_ADDR_CHANGE:
2009 case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2010 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n",
2011 rdma_event_msg(ev->event), ev->status);
2012 cm_err = -ECONNRESET;
2013 break;
2014 case RDMA_CM_EVENT_ADDR_ERROR:
2015 case RDMA_CM_EVENT_ROUTE_ERROR:
2016 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n",
2017 rdma_event_msg(ev->event), ev->status);
2018 cm_err = -EHOSTUNREACH;
2019 break;
2020 case RDMA_CM_EVENT_DEVICE_REMOVAL:
2021 /*
2022 * Device removal is a special case. Queue close and return 0.
2023 */
2024 rtrs_clt_close_conns(clt_path, false);
2025 return 0;
2026 default:
2027 rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n",
2028 rdma_event_msg(ev->event), ev->status);
2029 cm_err = -ECONNRESET;
2030 break;
2031 }
2032
2033 if (cm_err) {
2034 /*
2035 * cm error makes sense only on connection establishing,
2036 * in other cases we rely on normal procedure of reconnecting.
2037 */
2038 flag_error_on_conn(con, cm_err);
2039 rtrs_rdma_error_recovery(con);
2040 }
2041
2042 return 0;
2043 }
2044
2045 /* The caller should do the cleanup in case of error */
create_cm(struct rtrs_clt_con * con)2046 static int create_cm(struct rtrs_clt_con *con)
2047 {
2048 struct rtrs_path *s = con->c.path;
2049 struct rtrs_clt_path *clt_path = to_clt_path(s);
2050 struct rdma_cm_id *cm_id;
2051 int err;
2052
2053 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con,
2054 clt_path->s.dst_addr.ss_family == AF_IB ?
2055 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC);
2056 if (IS_ERR(cm_id)) {
2057 err = PTR_ERR(cm_id);
2058 rtrs_err(s, "Failed to create CM ID, err: %d\n", err);
2059
2060 return err;
2061 }
2062 con->c.cm_id = cm_id;
2063 con->cm_err = 0;
2064 /* allow the port to be reused */
2065 err = rdma_set_reuseaddr(cm_id, 1);
2066 if (err != 0) {
2067 rtrs_err(s, "Set address reuse failed, err: %d\n", err);
2068 return err;
2069 }
2070 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr,
2071 (struct sockaddr *)&clt_path->s.dst_addr,
2072 RTRS_CONNECT_TIMEOUT_MS);
2073 if (err) {
2074 rtrs_err(s, "Failed to resolve address, err: %d\n", err);
2075 return err;
2076 }
2077 /*
2078 * Combine connection status and session events. This is needed
2079 * for waiting two possible cases: cm_err has something meaningful
2080 * or session state was really changed to error by device removal.
2081 */
2082 err = wait_event_interruptible_timeout(
2083 clt_path->state_wq,
2084 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING,
2085 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
2086 if (err == 0 || err == -ERESTARTSYS) {
2087 if (err == 0)
2088 err = -ETIMEDOUT;
2089 /* Timedout or interrupted */
2090 return err;
2091 }
2092 if (con->cm_err < 0)
2093 return con->cm_err;
2094 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING)
2095 /* Device removal */
2096 return -ECONNABORTED;
2097
2098 return 0;
2099 }
2100
rtrs_clt_path_up(struct rtrs_clt_path * clt_path)2101 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path)
2102 {
2103 struct rtrs_clt_sess *clt = clt_path->clt;
2104 int up;
2105
2106 /*
2107 * We can fire RECONNECTED event only when all paths were
2108 * connected on rtrs_clt_open(), then each was disconnected
2109 * and the first one connected again. That's why this nasty
2110 * game with counter value.
2111 */
2112
2113 mutex_lock(&clt->paths_ev_mutex);
2114 up = ++clt->paths_up;
2115 /*
2116 * Here it is safe to access paths num directly since up counter
2117 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is
2118 * in progress, thus paths removals are impossible.
2119 */
2120 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num)
2121 clt->paths_up = clt->paths_num;
2122 else if (up == 1)
2123 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED);
2124 mutex_unlock(&clt->paths_ev_mutex);
2125
2126 /* Mark session as established */
2127 clt_path->established = true;
2128 clt_path->reconnect_attempts = 0;
2129 clt_path->stats->reconnects.successful_cnt++;
2130 }
2131
rtrs_clt_path_down(struct rtrs_clt_path * clt_path)2132 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path)
2133 {
2134 struct rtrs_clt_sess *clt = clt_path->clt;
2135
2136 if (!clt_path->established)
2137 return;
2138
2139 clt_path->established = false;
2140 mutex_lock(&clt->paths_ev_mutex);
2141 WARN_ON(!clt->paths_up);
2142 if (--clt->paths_up == 0)
2143 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED);
2144 mutex_unlock(&clt->paths_ev_mutex);
2145 }
2146
rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path * clt_path)2147 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path)
2148 {
2149 struct rtrs_clt_con *con;
2150 unsigned int cid;
2151
2152 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED);
2153
2154 /*
2155 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes
2156 * exactly in between. Start destroying after it finishes.
2157 */
2158 mutex_lock(&clt_path->init_mutex);
2159 mutex_unlock(&clt_path->init_mutex);
2160
2161 /*
2162 * All IO paths must observe !CONNECTED state before we
2163 * free everything.
2164 */
2165 synchronize_rcu();
2166
2167 rtrs_stop_hb(&clt_path->s);
2168
2169 /*
2170 * The order it utterly crucial: firstly disconnect and complete all
2171 * rdma requests with error (thus set in_use=false for requests),
2172 * then fail outstanding requests checking in_use for each, and
2173 * eventually notify upper layer about session disconnection.
2174 */
2175
2176 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2177 if (!clt_path->s.con[cid])
2178 break;
2179 con = to_clt_con(clt_path->s.con[cid]);
2180 stop_cm(con);
2181 }
2182 fail_all_outstanding_reqs(clt_path);
2183 free_path_reqs(clt_path);
2184 rtrs_clt_path_down(clt_path);
2185
2186 /*
2187 * Wait for graceful shutdown, namely when peer side invokes
2188 * rdma_disconnect(). 'connected_cnt' is decremented only on
2189 * CM events, thus if other side had crashed and hb has detected
2190 * something is wrong, here we will stuck for exactly timeout ms,
2191 * since CM does not fire anything. That is fine, we are not in
2192 * hurry.
2193 */
2194 wait_event_timeout(clt_path->state_wq,
2195 !atomic_read(&clt_path->connected_cnt),
2196 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
2197
2198 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2199 if (!clt_path->s.con[cid])
2200 break;
2201 con = to_clt_con(clt_path->s.con[cid]);
2202 mutex_lock(&con->con_mutex);
2203 destroy_con_cq_qp(con);
2204 mutex_unlock(&con->con_mutex);
2205 destroy_cm(con);
2206 destroy_con(con);
2207 }
2208 }
2209
rtrs_clt_remove_path_from_arr(struct rtrs_clt_path * clt_path)2210 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path)
2211 {
2212 struct rtrs_clt_sess *clt = clt_path->clt;
2213 struct rtrs_clt_path *next;
2214 bool wait_for_grace = false;
2215 int cpu;
2216
2217 mutex_lock(&clt->paths_mutex);
2218 list_del_rcu(&clt_path->s.entry);
2219
2220 /* Make sure everybody observes path removal. */
2221 synchronize_rcu();
2222
2223 /*
2224 * At this point nobody sees @sess in the list, but still we have
2225 * dangling pointer @pcpu_path which _can_ point to @sess. Since
2226 * nobody can observe @sess in the list, we guarantee that IO path
2227 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal
2228 * to @sess, but can never again become @sess.
2229 */
2230
2231 /*
2232 * Decrement paths number only after grace period, because
2233 * caller of do_each_path() must firstly observe list without
2234 * path and only then decremented paths number.
2235 *
2236 * Otherwise there can be the following situation:
2237 * o Two paths exist and IO is coming.
2238 * o One path is removed:
2239 * CPU#0 CPU#1
2240 * do_each_path(): rtrs_clt_remove_path_from_arr():
2241 * path = get_next_path()
2242 * ^^^ list_del_rcu(path)
2243 * [!CONNECTED path] clt->paths_num--
2244 * ^^^^^^^^^
2245 * load clt->paths_num from 2 to 1
2246 * ^^^^^^^^^
2247 * sees 1
2248 *
2249 * path is observed as !CONNECTED, but do_each_path() loop
2250 * ends, because expression i < clt->paths_num is false.
2251 */
2252 clt->paths_num--;
2253
2254 /*
2255 * Get @next connection from current @sess which is going to be
2256 * removed. If @sess is the last element, then @next is NULL.
2257 */
2258 rcu_read_lock();
2259 next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path);
2260 rcu_read_unlock();
2261
2262 /*
2263 * @pcpu paths can still point to the path which is going to be
2264 * removed, so change the pointer manually.
2265 */
2266 for_each_possible_cpu(cpu) {
2267 struct rtrs_clt_path __rcu **ppcpu_path;
2268
2269 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu);
2270 if (rcu_dereference_protected(*ppcpu_path,
2271 lockdep_is_held(&clt->paths_mutex)) != clt_path)
2272 /*
2273 * synchronize_rcu() was called just after deleting
2274 * entry from the list, thus IO code path cannot
2275 * change pointer back to the pointer which is going
2276 * to be removed, we are safe here.
2277 */
2278 continue;
2279
2280 /*
2281 * We race with IO code path, which also changes pointer,
2282 * thus we have to be careful not to overwrite it.
2283 */
2284 if (try_cmpxchg((struct rtrs_clt_path **)ppcpu_path, &clt_path,
2285 next))
2286 /*
2287 * @ppcpu_path was successfully replaced with @next,
2288 * that means that someone could also pick up the
2289 * @sess and dereferencing it right now, so wait for
2290 * a grace period is required.
2291 */
2292 wait_for_grace = true;
2293 }
2294 if (wait_for_grace)
2295 synchronize_rcu();
2296
2297 mutex_unlock(&clt->paths_mutex);
2298 }
2299
rtrs_clt_add_path_to_arr(struct rtrs_clt_path * clt_path)2300 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path)
2301 {
2302 struct rtrs_clt_sess *clt = clt_path->clt;
2303
2304 mutex_lock(&clt->paths_mutex);
2305 clt->paths_num++;
2306
2307 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
2308 mutex_unlock(&clt->paths_mutex);
2309 }
2310
rtrs_clt_close_work(struct work_struct * work)2311 static void rtrs_clt_close_work(struct work_struct *work)
2312 {
2313 struct rtrs_clt_path *clt_path;
2314
2315 clt_path = container_of(work, struct rtrs_clt_path, close_work);
2316
2317 cancel_work_sync(&clt_path->err_recovery_work);
2318 cancel_delayed_work_sync(&clt_path->reconnect_dwork);
2319 rtrs_clt_stop_and_destroy_conns(clt_path);
2320 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL);
2321 }
2322
init_conns(struct rtrs_clt_path * clt_path)2323 static int init_conns(struct rtrs_clt_path *clt_path)
2324 {
2325 unsigned int cid;
2326 int err, i;
2327
2328 /*
2329 * On every new session connections increase reconnect counter
2330 * to avoid clashes with previous sessions not yet closed
2331 * sessions on a server side.
2332 */
2333 clt_path->s.recon_cnt++;
2334
2335 /* Establish all RDMA connections */
2336 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2337 err = create_con(clt_path, cid);
2338 if (err)
2339 goto destroy;
2340
2341 err = create_cm(to_clt_con(clt_path->s.con[cid]));
2342 if (err)
2343 goto destroy;
2344 }
2345
2346 /*
2347 * Set the cid to con_num - 1, since if we fail later, we want to stay in bounds.
2348 */
2349 cid = clt_path->s.con_num - 1;
2350
2351 err = alloc_path_reqs(clt_path);
2352 if (err)
2353 goto destroy;
2354
2355 return 0;
2356
2357 destroy:
2358 /* Make sure we do the cleanup in the order they are created */
2359 for (i = 0; i <= cid; i++) {
2360 struct rtrs_clt_con *con;
2361
2362 if (!clt_path->s.con[i])
2363 break;
2364
2365 con = to_clt_con(clt_path->s.con[i]);
2366 if (con->c.cm_id) {
2367 stop_cm(con);
2368 mutex_lock(&con->con_mutex);
2369 destroy_con_cq_qp(con);
2370 mutex_unlock(&con->con_mutex);
2371 destroy_cm(con);
2372 }
2373 destroy_con(con);
2374 }
2375 /*
2376 * If we've never taken async path and got an error, say,
2377 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state
2378 * manually to keep reconnecting.
2379 */
2380 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
2381
2382 return err;
2383 }
2384
rtrs_clt_info_req_done(struct ib_cq * cq,struct ib_wc * wc)2385 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc)
2386 {
2387 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
2388 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
2389 struct rtrs_iu *iu;
2390
2391 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
2392 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
2393
2394 if (wc->status != IB_WC_SUCCESS) {
2395 rtrs_err(clt_path->clt, "Path info request send failed: %s\n",
2396 ib_wc_status_msg(wc->status));
2397 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
2398 return;
2399 }
2400
2401 rtrs_clt_update_wc_stats(con);
2402 }
2403
process_info_rsp(struct rtrs_clt_path * clt_path,const struct rtrs_msg_info_rsp * msg)2404 static int process_info_rsp(struct rtrs_clt_path *clt_path,
2405 const struct rtrs_msg_info_rsp *msg)
2406 {
2407 unsigned int sg_cnt, total_len;
2408 int i, sgi;
2409
2410 sg_cnt = le16_to_cpu(msg->sg_cnt);
2411 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) {
2412 rtrs_err(clt_path->clt,
2413 "Incorrect sg_cnt %d, is not multiple\n",
2414 sg_cnt);
2415 return -EINVAL;
2416 }
2417
2418 /*
2419 * Check if IB immediate data size is enough to hold the mem_id and
2420 * the offset inside the memory chunk.
2421 */
2422 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) >
2423 MAX_IMM_PAYL_BITS) {
2424 rtrs_err(clt_path->clt,
2425 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n",
2426 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size);
2427 return -EINVAL;
2428 }
2429 total_len = 0;
2430 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) {
2431 const struct rtrs_sg_desc *desc = &msg->desc[sgi];
2432 u32 len, rkey;
2433 u64 addr;
2434
2435 addr = le64_to_cpu(desc->addr);
2436 rkey = le32_to_cpu(desc->key);
2437 len = le32_to_cpu(desc->len);
2438
2439 total_len += len;
2440
2441 if (!len || (len % clt_path->chunk_size)) {
2442 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n",
2443 sgi,
2444 len);
2445 return -EINVAL;
2446 }
2447 for ( ; len && i < clt_path->queue_depth; i++) {
2448 clt_path->rbufs[i].addr = addr;
2449 clt_path->rbufs[i].rkey = rkey;
2450
2451 len -= clt_path->chunk_size;
2452 addr += clt_path->chunk_size;
2453 }
2454 }
2455 /* Sanity check */
2456 if (sgi != sg_cnt || i != clt_path->queue_depth) {
2457 rtrs_err(clt_path->clt,
2458 "Incorrect sg vector, not fully mapped\n");
2459 return -EINVAL;
2460 }
2461 if (total_len != clt_path->chunk_size * clt_path->queue_depth) {
2462 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len);
2463 return -EINVAL;
2464 }
2465
2466 return 0;
2467 }
2468
rtrs_clt_info_rsp_done(struct ib_cq * cq,struct ib_wc * wc)2469 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc)
2470 {
2471 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
2472 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
2473 struct rtrs_msg_info_rsp *msg;
2474 enum rtrs_clt_state state;
2475 struct rtrs_iu *iu;
2476 size_t rx_sz;
2477 int err;
2478
2479 state = RTRS_CLT_CONNECTING_ERR;
2480
2481 WARN_ON(con->c.cid);
2482 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
2483 if (wc->status != IB_WC_SUCCESS) {
2484 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n",
2485 ib_wc_status_msg(wc->status));
2486 goto out;
2487 }
2488 WARN_ON(wc->opcode != IB_WC_RECV);
2489
2490 if (wc->byte_len < sizeof(*msg)) {
2491 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
2492 wc->byte_len);
2493 goto out;
2494 }
2495 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
2496 iu->size, DMA_FROM_DEVICE);
2497 msg = iu->buf;
2498 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) {
2499 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n",
2500 le16_to_cpu(msg->type));
2501 goto out;
2502 }
2503 rx_sz = sizeof(*msg);
2504 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt);
2505 if (wc->byte_len < rx_sz) {
2506 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
2507 wc->byte_len);
2508 goto out;
2509 }
2510 err = process_info_rsp(clt_path, msg);
2511 if (err)
2512 goto out;
2513
2514 err = post_recv_path(clt_path);
2515 if (err)
2516 goto out;
2517
2518 state = RTRS_CLT_CONNECTED;
2519
2520 out:
2521 rtrs_clt_update_wc_stats(con);
2522 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
2523 rtrs_clt_change_state_get_old(clt_path, state, NULL);
2524 }
2525
rtrs_send_path_info(struct rtrs_clt_path * clt_path)2526 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path)
2527 {
2528 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]);
2529 struct rtrs_msg_info_req *msg;
2530 struct rtrs_iu *tx_iu, *rx_iu;
2531 size_t rx_sz;
2532 int err;
2533
2534 rx_sz = sizeof(struct rtrs_msg_info_rsp);
2535 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth;
2536
2537 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL,
2538 clt_path->s.dev->ib_dev, DMA_TO_DEVICE,
2539 rtrs_clt_info_req_done);
2540 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev,
2541 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done);
2542 if (!tx_iu || !rx_iu) {
2543 err = -ENOMEM;
2544 goto out;
2545 }
2546 /* Prepare for getting info response */
2547 err = rtrs_iu_post_recv(&usr_con->c, rx_iu);
2548 if (err) {
2549 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err);
2550 goto out;
2551 }
2552 rx_iu = NULL;
2553
2554 msg = tx_iu->buf;
2555 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ);
2556 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname));
2557
2558 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
2559 tx_iu->dma_addr,
2560 tx_iu->size, DMA_TO_DEVICE);
2561
2562 /* Send info request */
2563 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL);
2564 if (err) {
2565 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err);
2566 goto out;
2567 }
2568 tx_iu = NULL;
2569
2570 /* Wait for state change */
2571 wait_event_interruptible_timeout(clt_path->state_wq,
2572 clt_path->state != RTRS_CLT_CONNECTING,
2573 msecs_to_jiffies(
2574 RTRS_CONNECT_TIMEOUT_MS));
2575 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) {
2576 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR)
2577 err = -ECONNRESET;
2578 else
2579 err = -ETIMEDOUT;
2580 }
2581
2582 out:
2583 if (tx_iu)
2584 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1);
2585 if (rx_iu)
2586 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1);
2587 if (err)
2588 /* If we've never taken async path because of malloc problems */
2589 rtrs_clt_change_state_get_old(clt_path,
2590 RTRS_CLT_CONNECTING_ERR, NULL);
2591
2592 return err;
2593 }
2594
2595 /**
2596 * init_path() - establishes all path connections and does handshake
2597 * @clt_path: client path.
2598 * In case of error full close or reconnect procedure should be taken,
2599 * because reconnect or close async works can be started.
2600 */
init_path(struct rtrs_clt_path * clt_path)2601 static int init_path(struct rtrs_clt_path *clt_path)
2602 {
2603 int err;
2604 char str[NAME_MAX];
2605 struct rtrs_addr path = {
2606 .src = &clt_path->s.src_addr,
2607 .dst = &clt_path->s.dst_addr,
2608 };
2609
2610 rtrs_addr_to_str(&path, str, sizeof(str));
2611
2612 mutex_lock(&clt_path->init_mutex);
2613 err = init_conns(clt_path);
2614 if (err) {
2615 rtrs_err(clt_path->clt,
2616 "init_conns() failed: err=%d path=%s [%s:%u]\n", err,
2617 str, clt_path->hca_name, clt_path->hca_port);
2618 goto out;
2619 }
2620 err = rtrs_send_path_info(clt_path);
2621 if (err) {
2622 rtrs_err(clt_path->clt,
2623 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n",
2624 err, str, clt_path->hca_name, clt_path->hca_port);
2625 goto out;
2626 }
2627 rtrs_clt_path_up(clt_path);
2628 rtrs_start_hb(&clt_path->s);
2629 out:
2630 mutex_unlock(&clt_path->init_mutex);
2631
2632 return err;
2633 }
2634
rtrs_clt_reconnect_work(struct work_struct * work)2635 static void rtrs_clt_reconnect_work(struct work_struct *work)
2636 {
2637 struct rtrs_clt_path *clt_path;
2638 struct rtrs_clt_sess *clt;
2639 int err;
2640
2641 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path,
2642 reconnect_dwork);
2643 clt = clt_path->clt;
2644
2645 trace_rtrs_clt_reconnect_work(clt_path);
2646
2647 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING)
2648 return;
2649
2650 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) {
2651 /* Close a path completely if max attempts is reached */
2652 rtrs_clt_close_conns(clt_path, false);
2653 return;
2654 }
2655 clt_path->reconnect_attempts++;
2656
2657 msleep(RTRS_RECONNECT_BACKOFF);
2658 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) {
2659 err = init_path(clt_path);
2660 if (err)
2661 goto reconnect_again;
2662 }
2663
2664 return;
2665
2666 reconnect_again:
2667 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) {
2668 clt_path->stats->reconnects.fail_cnt++;
2669 queue_work(rtrs_wq, &clt_path->err_recovery_work);
2670 }
2671 }
2672
rtrs_clt_dev_release(struct device * dev)2673 static void rtrs_clt_dev_release(struct device *dev)
2674 {
2675 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess,
2676 dev);
2677
2678 mutex_destroy(&clt->paths_ev_mutex);
2679 mutex_destroy(&clt->paths_mutex);
2680 kfree(clt);
2681 }
2682
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)2683 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num,
2684 u16 port, size_t pdu_sz, void *priv,
2685 void (*link_ev)(void *priv,
2686 enum rtrs_clt_link_ev ev),
2687 unsigned int reconnect_delay_sec,
2688 unsigned int max_reconnect_attempts)
2689 {
2690 struct rtrs_clt_sess *clt;
2691 int err;
2692
2693 if (!paths_num || paths_num > MAX_PATHS_NUM)
2694 return ERR_PTR(-EINVAL);
2695
2696 if (strlen(sessname) >= sizeof(clt->sessname))
2697 return ERR_PTR(-EINVAL);
2698
2699 clt = kzalloc(sizeof(*clt), GFP_KERNEL);
2700 if (!clt)
2701 return ERR_PTR(-ENOMEM);
2702
2703 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path));
2704 if (!clt->pcpu_path) {
2705 kfree(clt);
2706 return ERR_PTR(-ENOMEM);
2707 }
2708
2709 clt->dev.class = &rtrs_clt_dev_class;
2710 clt->dev.release = rtrs_clt_dev_release;
2711 uuid_gen(&clt->paths_uuid);
2712 INIT_LIST_HEAD_RCU(&clt->paths_list);
2713 clt->paths_num = paths_num;
2714 clt->paths_up = MAX_PATHS_NUM;
2715 clt->port = port;
2716 clt->pdu_sz = pdu_sz;
2717 clt->max_segments = RTRS_MAX_SEGMENTS;
2718 clt->reconnect_delay_sec = reconnect_delay_sec;
2719 clt->max_reconnect_attempts = max_reconnect_attempts;
2720 clt->priv = priv;
2721 clt->link_ev = link_ev;
2722 clt->mp_policy = MP_POLICY_MIN_INFLIGHT;
2723 strscpy(clt->sessname, sessname, sizeof(clt->sessname));
2724 init_waitqueue_head(&clt->permits_wait);
2725 mutex_init(&clt->paths_ev_mutex);
2726 mutex_init(&clt->paths_mutex);
2727 device_initialize(&clt->dev);
2728
2729 err = dev_set_name(&clt->dev, "%s", sessname);
2730 if (err)
2731 goto err_put;
2732
2733 /*
2734 * Suppress user space notification until
2735 * sysfs files are created
2736 */
2737 dev_set_uevent_suppress(&clt->dev, true);
2738 err = device_add(&clt->dev);
2739 if (err)
2740 goto err_put;
2741
2742 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj);
2743 if (!clt->kobj_paths) {
2744 err = -ENOMEM;
2745 goto err_del;
2746 }
2747 err = rtrs_clt_create_sysfs_root_files(clt);
2748 if (err) {
2749 kobject_del(clt->kobj_paths);
2750 kobject_put(clt->kobj_paths);
2751 goto err_del;
2752 }
2753 dev_set_uevent_suppress(&clt->dev, false);
2754 kobject_uevent(&clt->dev.kobj, KOBJ_ADD);
2755
2756 return clt;
2757 err_del:
2758 device_del(&clt->dev);
2759 err_put:
2760 free_percpu(clt->pcpu_path);
2761 put_device(&clt->dev);
2762 return ERR_PTR(err);
2763 }
2764
free_clt(struct rtrs_clt_sess * clt)2765 static void free_clt(struct rtrs_clt_sess *clt)
2766 {
2767 free_percpu(clt->pcpu_path);
2768
2769 /*
2770 * release callback will free clt and destroy mutexes in last put
2771 */
2772 device_unregister(&clt->dev);
2773 }
2774
2775 /**
2776 * rtrs_clt_open() - Open a path to an RTRS server
2777 * @ops: holds the link event callback and the private pointer.
2778 * @pathname: name of the path to an RTRS server
2779 * @paths: Paths to be established defined by their src and dst addresses
2780 * @paths_num: Number of elements in the @paths array
2781 * @port: port to be used by the RTRS session
2782 * @pdu_sz: Size of extra payload which can be accessed after permit allocation.
2783 * @reconnect_delay_sec: time between reconnect tries
2784 * @max_reconnect_attempts: Number of times to reconnect on error before giving
2785 * up, 0 for * disabled, -1 for forever
2786 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag
2787 *
2788 * Starts session establishment with the rtrs_server. The function can block
2789 * up to ~2000ms before it returns.
2790 *
2791 * Return a valid pointer on success otherwise PTR_ERR.
2792 */
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)2793 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops,
2794 const char *pathname,
2795 const struct rtrs_addr *paths,
2796 size_t paths_num, u16 port,
2797 size_t pdu_sz, u8 reconnect_delay_sec,
2798 s16 max_reconnect_attempts, u32 nr_poll_queues)
2799 {
2800 struct rtrs_clt_path *clt_path, *tmp;
2801 struct rtrs_clt_sess *clt;
2802 int err, i;
2803
2804 if (strchr(pathname, '/') || strchr(pathname, '.')) {
2805 pr_err("pathname cannot contain / and .\n");
2806 err = -EINVAL;
2807 goto out;
2808 }
2809
2810 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv,
2811 ops->link_ev,
2812 reconnect_delay_sec,
2813 max_reconnect_attempts);
2814 if (IS_ERR(clt)) {
2815 err = PTR_ERR(clt);
2816 goto out;
2817 }
2818 for (i = 0; i < paths_num; i++) {
2819 struct rtrs_clt_path *clt_path;
2820
2821 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids,
2822 nr_poll_queues);
2823 if (IS_ERR(clt_path)) {
2824 err = PTR_ERR(clt_path);
2825 goto close_all_path;
2826 }
2827 if (!i)
2828 clt_path->for_new_clt = 1;
2829 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
2830
2831 err = init_path(clt_path);
2832 if (err) {
2833 list_del_rcu(&clt_path->s.entry);
2834 rtrs_clt_close_conns(clt_path, true);
2835 free_percpu(clt_path->stats->pcpu_stats);
2836 kfree(clt_path->stats);
2837 free_path(clt_path);
2838 goto close_all_path;
2839 }
2840
2841 err = rtrs_clt_create_path_files(clt_path);
2842 if (err) {
2843 list_del_rcu(&clt_path->s.entry);
2844 rtrs_clt_close_conns(clt_path, true);
2845 free_percpu(clt_path->stats->pcpu_stats);
2846 kfree(clt_path->stats);
2847 free_path(clt_path);
2848 goto close_all_path;
2849 }
2850 }
2851 err = alloc_permits(clt);
2852 if (err)
2853 goto close_all_path;
2854
2855 return clt;
2856
2857 close_all_path:
2858 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
2859 rtrs_clt_destroy_path_files(clt_path, NULL);
2860 rtrs_clt_close_conns(clt_path, true);
2861 kobject_put(&clt_path->kobj);
2862 }
2863 rtrs_clt_destroy_sysfs_root(clt);
2864 free_clt(clt);
2865
2866 out:
2867 return ERR_PTR(err);
2868 }
2869 EXPORT_SYMBOL(rtrs_clt_open);
2870
2871 /**
2872 * rtrs_clt_close() - Close a path
2873 * @clt: Session handle. Session is freed upon return.
2874 */
rtrs_clt_close(struct rtrs_clt_sess * clt)2875 void rtrs_clt_close(struct rtrs_clt_sess *clt)
2876 {
2877 struct rtrs_clt_path *clt_path, *tmp;
2878
2879 /* Firstly forbid sysfs access */
2880 rtrs_clt_destroy_sysfs_root(clt);
2881
2882 /* Now it is safe to iterate over all paths without locks */
2883 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
2884 rtrs_clt_close_conns(clt_path, true);
2885 rtrs_clt_destroy_path_files(clt_path, NULL);
2886 kobject_put(&clt_path->kobj);
2887 }
2888 free_permits(clt);
2889 free_clt(clt);
2890 }
2891 EXPORT_SYMBOL(rtrs_clt_close);
2892
rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path * clt_path)2893 int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path)
2894 {
2895 enum rtrs_clt_state old_state;
2896 int err = -EBUSY;
2897 bool changed;
2898
2899 changed = rtrs_clt_change_state_get_old(clt_path,
2900 RTRS_CLT_RECONNECTING,
2901 &old_state);
2902 if (changed) {
2903 clt_path->reconnect_attempts = 0;
2904 rtrs_clt_stop_and_destroy_conns(clt_path);
2905 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0);
2906 }
2907 if (changed || old_state == RTRS_CLT_RECONNECTING) {
2908 /*
2909 * flush_delayed_work() queues pending work for immediate
2910 * execution, so do the flush if we have queued something
2911 * right now or work is pending.
2912 */
2913 flush_delayed_work(&clt_path->reconnect_dwork);
2914 err = (READ_ONCE(clt_path->state) ==
2915 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN);
2916 }
2917
2918 return err;
2919 }
2920
rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path * clt_path,const struct attribute * sysfs_self)2921 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path,
2922 const struct attribute *sysfs_self)
2923 {
2924 enum rtrs_clt_state old_state;
2925 bool changed;
2926
2927 /*
2928 * Continue stopping path till state was changed to DEAD or
2929 * state was observed as DEAD:
2930 * 1. State was changed to DEAD - we were fast and nobody
2931 * invoked rtrs_clt_reconnect(), which can again start
2932 * reconnecting.
2933 * 2. State was observed as DEAD - we have someone in parallel
2934 * removing the path.
2935 */
2936 do {
2937 rtrs_clt_close_conns(clt_path, true);
2938 changed = rtrs_clt_change_state_get_old(clt_path,
2939 RTRS_CLT_DEAD,
2940 &old_state);
2941 } while (!changed && old_state != RTRS_CLT_DEAD);
2942
2943 if (changed) {
2944 rtrs_clt_remove_path_from_arr(clt_path);
2945 rtrs_clt_destroy_path_files(clt_path, sysfs_self);
2946 kobject_put(&clt_path->kobj);
2947 }
2948
2949 return 0;
2950 }
2951
rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess * clt,int value)2952 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value)
2953 {
2954 clt->max_reconnect_attempts = (unsigned int)value;
2955 }
2956
rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess * clt)2957 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt)
2958 {
2959 return (int)clt->max_reconnect_attempts;
2960 }
2961
2962 /**
2963 * rtrs_clt_request() - Request data transfer to/from server via RDMA.
2964 *
2965 * @dir: READ/WRITE
2966 * @ops: callback function to be called as confirmation, and the pointer.
2967 * @clt: Session
2968 * @permit: Preallocated permit
2969 * @vec: Message that is sent to server together with the request.
2970 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE.
2971 * Since the msg is copied internally it can be allocated on stack.
2972 * @nr: Number of elements in @vec.
2973 * @data_len: length of data sent to/from server
2974 * @sg: Pages to be sent/received to/from server.
2975 * @sg_cnt: Number of elements in the @sg
2976 *
2977 * Return:
2978 * 0: Success
2979 * <0: Error
2980 *
2981 * On dir=READ rtrs client will request a data transfer from Server to client.
2982 * The data that the server will respond with will be stored in @sg when
2983 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event.
2984 * On dir=WRITE rtrs client will rdma write data in sg to server side.
2985 */
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)2986 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
2987 struct rtrs_clt_sess *clt, struct rtrs_permit *permit,
2988 const struct kvec *vec, size_t nr, size_t data_len,
2989 struct scatterlist *sg, unsigned int sg_cnt)
2990 {
2991 struct rtrs_clt_io_req *req;
2992 struct rtrs_clt_path *clt_path;
2993
2994 enum dma_data_direction dma_dir;
2995 int err = -ECONNABORTED, i;
2996 size_t usr_len, hdr_len;
2997 struct path_it it;
2998
2999 /* Get kvec length */
3000 for (i = 0, usr_len = 0; i < nr; i++)
3001 usr_len += vec[i].iov_len;
3002
3003 if (dir == READ) {
3004 hdr_len = sizeof(struct rtrs_msg_rdma_read) +
3005 sg_cnt * sizeof(struct rtrs_sg_desc);
3006 dma_dir = DMA_FROM_DEVICE;
3007 } else {
3008 hdr_len = sizeof(struct rtrs_msg_rdma_write);
3009 dma_dir = DMA_TO_DEVICE;
3010 }
3011
3012 rcu_read_lock();
3013 for (path_it_init(&it, clt);
3014 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
3015 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
3016 continue;
3017
3018 if (usr_len + hdr_len > clt_path->max_hdr_size) {
3019 rtrs_wrn_rl(clt_path->clt,
3020 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n",
3021 dir == READ ? "Read" : "Write",
3022 usr_len, hdr_len, clt_path->max_hdr_size);
3023 err = -EMSGSIZE;
3024 break;
3025 }
3026 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv,
3027 vec, usr_len, sg, sg_cnt, data_len,
3028 dma_dir);
3029 if (dir == READ)
3030 err = rtrs_clt_read_req(req);
3031 else
3032 err = rtrs_clt_write_req(req);
3033 if (err) {
3034 req->in_use = false;
3035 continue;
3036 }
3037 /* Success path */
3038 break;
3039 }
3040 path_it_deinit(&it);
3041 rcu_read_unlock();
3042
3043 return err;
3044 }
3045 EXPORT_SYMBOL(rtrs_clt_request);
3046
rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess * clt,unsigned int index)3047 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index)
3048 {
3049 /* If no path, return -1 for block layer not to try again */
3050 int cnt = -1;
3051 struct rtrs_con *con;
3052 struct rtrs_clt_path *clt_path;
3053 struct path_it it;
3054
3055 rcu_read_lock();
3056 for (path_it_init(&it, clt);
3057 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
3058 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
3059 continue;
3060
3061 con = clt_path->s.con[index + 1];
3062 cnt = ib_process_cq_direct(con->cq, -1);
3063 if (cnt)
3064 break;
3065 }
3066 path_it_deinit(&it);
3067 rcu_read_unlock();
3068
3069 return cnt;
3070 }
3071 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct);
3072
3073 /**
3074 * rtrs_clt_query() - queries RTRS session attributes
3075 *@clt: session pointer
3076 *@attr: query results for session attributes.
3077 * Returns:
3078 * 0 on success
3079 * -ECOMM no connection to the server
3080 */
rtrs_clt_query(struct rtrs_clt_sess * clt,struct rtrs_attrs * attr)3081 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr)
3082 {
3083 if (!rtrs_clt_is_connected(clt))
3084 return -ECOMM;
3085
3086 attr->queue_depth = clt->queue_depth;
3087 attr->max_segments = clt->max_segments;
3088 /* Cap max_io_size to min of remote buffer size and the fr pages */
3089 attr->max_io_size = min_t(int, clt->max_io_size,
3090 clt->max_segments * SZ_4K);
3091
3092 return 0;
3093 }
3094 EXPORT_SYMBOL(rtrs_clt_query);
3095
rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess * clt,struct rtrs_addr * addr)3096 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt,
3097 struct rtrs_addr *addr)
3098 {
3099 struct rtrs_clt_path *clt_path;
3100 int err;
3101
3102 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0);
3103 if (IS_ERR(clt_path))
3104 return PTR_ERR(clt_path);
3105
3106 mutex_lock(&clt->paths_mutex);
3107 if (clt->paths_num == 0) {
3108 /*
3109 * When all the paths are removed for a session,
3110 * the addition of the first path is like a new session for
3111 * the storage server
3112 */
3113 clt_path->for_new_clt = 1;
3114 }
3115
3116 mutex_unlock(&clt->paths_mutex);
3117
3118 /*
3119 * It is totally safe to add path in CONNECTING state: coming
3120 * IO will never grab it. Also it is very important to add
3121 * path before init, since init fires LINK_CONNECTED event.
3122 */
3123 rtrs_clt_add_path_to_arr(clt_path);
3124
3125 err = init_path(clt_path);
3126 if (err)
3127 goto close_path;
3128
3129 err = rtrs_clt_create_path_files(clt_path);
3130 if (err)
3131 goto close_path;
3132
3133 return 0;
3134
3135 close_path:
3136 rtrs_clt_remove_path_from_arr(clt_path);
3137 rtrs_clt_close_conns(clt_path, true);
3138 free_percpu(clt_path->stats->pcpu_stats);
3139 kfree(clt_path->stats);
3140 free_path(clt_path);
3141
3142 return err;
3143 }
3144
rtrs_clt_ib_dev_init(struct rtrs_ib_dev * dev)3145 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev)
3146 {
3147 if (!(dev->ib_dev->attrs.device_cap_flags &
3148 IB_DEVICE_MEM_MGT_EXTENSIONS)) {
3149 pr_err("Memory registrations not supported.\n");
3150 return -ENOTSUPP;
3151 }
3152
3153 return 0;
3154 }
3155
3156 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = {
3157 .init = rtrs_clt_ib_dev_init
3158 };
3159
rtrs_client_init(void)3160 static int __init rtrs_client_init(void)
3161 {
3162 int ret = 0;
3163
3164 rtrs_rdma_dev_pd_init(0, &dev_pd);
3165 ret = class_register(&rtrs_clt_dev_class);
3166 if (ret) {
3167 pr_err("Failed to create rtrs-client dev class\n");
3168 return ret;
3169 }
3170 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0);
3171 if (!rtrs_wq) {
3172 class_unregister(&rtrs_clt_dev_class);
3173 return -ENOMEM;
3174 }
3175
3176 return 0;
3177 }
3178
rtrs_client_exit(void)3179 static void __exit rtrs_client_exit(void)
3180 {
3181 destroy_workqueue(rtrs_wq);
3182 class_unregister(&rtrs_clt_dev_class);
3183 rtrs_rdma_dev_pd_deinit(&dev_pd);
3184 }
3185
3186 module_init(rtrs_client_init);
3187 module_exit(rtrs_client_exit);
3188