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 struct class *rtrs_clt_dev_class;
49
rtrs_clt_is_connected(const struct rtrs_clt_sess * clt)50 static inline bool rtrs_clt_is_connected(const struct rtrs_clt_sess *clt)
51 {
52 struct rtrs_clt_path *clt_path;
53 bool connected = false;
54
55 rcu_read_lock();
56 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry)
57 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED) {
58 connected = true;
59 break;
60 }
61 rcu_read_unlock();
62
63 return connected;
64 }
65
66 static struct rtrs_permit *
__rtrs_get_permit(struct rtrs_clt_sess * clt,enum rtrs_clt_con_type con_type)67 __rtrs_get_permit(struct rtrs_clt_sess *clt, enum rtrs_clt_con_type con_type)
68 {
69 size_t max_depth = clt->queue_depth;
70 struct rtrs_permit *permit;
71 int bit;
72
73 /*
74 * Adapted from null_blk get_tag(). Callers from different cpus may
75 * grab the same bit, since find_first_zero_bit is not atomic.
76 * But then the test_and_set_bit_lock will fail for all the
77 * callers but one, so that they will loop again.
78 * This way an explicit spinlock is not required.
79 */
80 do {
81 bit = find_first_zero_bit(clt->permits_map, max_depth);
82 if (bit >= max_depth)
83 return NULL;
84 } while (test_and_set_bit_lock(bit, clt->permits_map));
85
86 permit = get_permit(clt, bit);
87 WARN_ON(permit->mem_id != bit);
88 permit->cpu_id = raw_smp_processor_id();
89 permit->con_type = con_type;
90
91 return permit;
92 }
93
__rtrs_put_permit(struct rtrs_clt_sess * clt,struct rtrs_permit * permit)94 static inline void __rtrs_put_permit(struct rtrs_clt_sess *clt,
95 struct rtrs_permit *permit)
96 {
97 clear_bit_unlock(permit->mem_id, clt->permits_map);
98 }
99
100 /**
101 * rtrs_clt_get_permit() - allocates permit for future RDMA operation
102 * @clt: Current session
103 * @con_type: Type of connection to use with the permit
104 * @can_wait: Wait type
105 *
106 * Description:
107 * Allocates permit for the following RDMA operation. Permit is used
108 * to preallocate all resources and to propagate memory pressure
109 * up earlier.
110 *
111 * Context:
112 * Can sleep if @wait == RTRS_PERMIT_WAIT
113 */
rtrs_clt_get_permit(struct rtrs_clt_sess * clt,enum rtrs_clt_con_type con_type,enum wait_type can_wait)114 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *clt,
115 enum rtrs_clt_con_type con_type,
116 enum wait_type can_wait)
117 {
118 struct rtrs_permit *permit;
119 DEFINE_WAIT(wait);
120
121 permit = __rtrs_get_permit(clt, con_type);
122 if (permit || !can_wait)
123 return permit;
124
125 do {
126 prepare_to_wait(&clt->permits_wait, &wait,
127 TASK_UNINTERRUPTIBLE);
128 permit = __rtrs_get_permit(clt, con_type);
129 if (permit)
130 break;
131
132 io_schedule();
133 } while (1);
134
135 finish_wait(&clt->permits_wait, &wait);
136
137 return permit;
138 }
139 EXPORT_SYMBOL(rtrs_clt_get_permit);
140
141 /**
142 * rtrs_clt_put_permit() - puts allocated permit
143 * @clt: Current session
144 * @permit: Permit to be freed
145 *
146 * Context:
147 * Does not matter
148 */
rtrs_clt_put_permit(struct rtrs_clt_sess * clt,struct rtrs_permit * permit)149 void rtrs_clt_put_permit(struct rtrs_clt_sess *clt,
150 struct rtrs_permit *permit)
151 {
152 if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map)))
153 return;
154
155 __rtrs_put_permit(clt, permit);
156
157 /*
158 * rtrs_clt_get_permit() adds itself to the &clt->permits_wait list
159 * before calling schedule(). So if rtrs_clt_get_permit() is sleeping
160 * it must have added itself to &clt->permits_wait before
161 * __rtrs_put_permit() finished.
162 * Hence it is safe to guard wake_up() with a waitqueue_active() test.
163 */
164 if (waitqueue_active(&clt->permits_wait))
165 wake_up(&clt->permits_wait);
166 }
167 EXPORT_SYMBOL(rtrs_clt_put_permit);
168
169 /**
170 * rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit
171 * @clt_path: client path pointer
172 * @permit: permit for the allocation of the RDMA buffer
173 * Note:
174 * IO connection starts from 1.
175 * 0 connection is for user messages.
176 */
177 static
rtrs_permit_to_clt_con(struct rtrs_clt_path * clt_path,struct rtrs_permit * permit)178 struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_path *clt_path,
179 struct rtrs_permit *permit)
180 {
181 int id = 0;
182
183 if (permit->con_type == RTRS_IO_CON)
184 id = (permit->cpu_id % (clt_path->s.irq_con_num - 1)) + 1;
185
186 return to_clt_con(clt_path->s.con[id]);
187 }
188
189 /**
190 * rtrs_clt_change_state() - change the session state through session state
191 * machine.
192 *
193 * @clt_path: client path to change the state of.
194 * @new_state: state to change to.
195 *
196 * returns true if sess's state is changed to new state, otherwise return false.
197 *
198 * Locks:
199 * state_wq lock must be hold.
200 */
rtrs_clt_change_state(struct rtrs_clt_path * clt_path,enum rtrs_clt_state new_state)201 static bool rtrs_clt_change_state(struct rtrs_clt_path *clt_path,
202 enum rtrs_clt_state new_state)
203 {
204 enum rtrs_clt_state old_state;
205 bool changed = false;
206
207 lockdep_assert_held(&clt_path->state_wq.lock);
208
209 old_state = clt_path->state;
210 switch (new_state) {
211 case RTRS_CLT_CONNECTING:
212 switch (old_state) {
213 case RTRS_CLT_RECONNECTING:
214 changed = true;
215 fallthrough;
216 default:
217 break;
218 }
219 break;
220 case RTRS_CLT_RECONNECTING:
221 switch (old_state) {
222 case RTRS_CLT_CONNECTED:
223 case RTRS_CLT_CONNECTING_ERR:
224 case RTRS_CLT_CLOSED:
225 changed = true;
226 fallthrough;
227 default:
228 break;
229 }
230 break;
231 case RTRS_CLT_CONNECTED:
232 switch (old_state) {
233 case RTRS_CLT_CONNECTING:
234 changed = true;
235 fallthrough;
236 default:
237 break;
238 }
239 break;
240 case RTRS_CLT_CONNECTING_ERR:
241 switch (old_state) {
242 case RTRS_CLT_CONNECTING:
243 changed = true;
244 fallthrough;
245 default:
246 break;
247 }
248 break;
249 case RTRS_CLT_CLOSING:
250 switch (old_state) {
251 case RTRS_CLT_CONNECTING:
252 case RTRS_CLT_CONNECTING_ERR:
253 case RTRS_CLT_RECONNECTING:
254 case RTRS_CLT_CONNECTED:
255 changed = true;
256 fallthrough;
257 default:
258 break;
259 }
260 break;
261 case RTRS_CLT_CLOSED:
262 switch (old_state) {
263 case RTRS_CLT_CLOSING:
264 changed = true;
265 fallthrough;
266 default:
267 break;
268 }
269 break;
270 case RTRS_CLT_DEAD:
271 switch (old_state) {
272 case RTRS_CLT_CLOSED:
273 changed = true;
274 fallthrough;
275 default:
276 break;
277 }
278 break;
279 default:
280 break;
281 }
282 if (changed) {
283 clt_path->state = new_state;
284 wake_up_locked(&clt_path->state_wq);
285 }
286
287 return changed;
288 }
289
rtrs_clt_change_state_from_to(struct rtrs_clt_path * clt_path,enum rtrs_clt_state old_state,enum rtrs_clt_state new_state)290 static bool rtrs_clt_change_state_from_to(struct rtrs_clt_path *clt_path,
291 enum rtrs_clt_state old_state,
292 enum rtrs_clt_state new_state)
293 {
294 bool changed = false;
295
296 spin_lock_irq(&clt_path->state_wq.lock);
297 if (clt_path->state == old_state)
298 changed = rtrs_clt_change_state(clt_path, new_state);
299 spin_unlock_irq(&clt_path->state_wq.lock);
300
301 return changed;
302 }
303
304 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path);
rtrs_rdma_error_recovery(struct rtrs_clt_con * con)305 static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con)
306 {
307 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
308
309 trace_rtrs_rdma_error_recovery(clt_path);
310
311 if (rtrs_clt_change_state_from_to(clt_path,
312 RTRS_CLT_CONNECTED,
313 RTRS_CLT_RECONNECTING)) {
314 queue_work(rtrs_wq, &clt_path->err_recovery_work);
315 } else {
316 /*
317 * Error can happen just on establishing new connection,
318 * so notify waiter with error state, waiter is responsible
319 * for cleaning the rest and reconnect if needed.
320 */
321 rtrs_clt_change_state_from_to(clt_path,
322 RTRS_CLT_CONNECTING,
323 RTRS_CLT_CONNECTING_ERR);
324 }
325 }
326
rtrs_clt_fast_reg_done(struct ib_cq * cq,struct ib_wc * wc)327 static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc)
328 {
329 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
330
331 if (wc->status != IB_WC_SUCCESS) {
332 rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n",
333 ib_wc_status_msg(wc->status));
334 rtrs_rdma_error_recovery(con);
335 }
336 }
337
338 static struct ib_cqe fast_reg_cqe = {
339 .done = rtrs_clt_fast_reg_done
340 };
341
342 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
343 bool notify, bool can_wait);
344
rtrs_clt_inv_rkey_done(struct ib_cq * cq,struct ib_wc * wc)345 static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
346 {
347 struct rtrs_clt_io_req *req =
348 container_of(wc->wr_cqe, typeof(*req), inv_cqe);
349 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
350
351 if (wc->status != IB_WC_SUCCESS) {
352 rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n",
353 ib_wc_status_msg(wc->status));
354 rtrs_rdma_error_recovery(con);
355 }
356 req->need_inv = false;
357 if (req->need_inv_comp)
358 complete(&req->inv_comp);
359 else
360 /* Complete request from INV callback */
361 complete_rdma_req(req, req->inv_errno, true, false);
362 }
363
rtrs_inv_rkey(struct rtrs_clt_io_req * req)364 static int rtrs_inv_rkey(struct rtrs_clt_io_req *req)
365 {
366 struct rtrs_clt_con *con = req->con;
367 struct ib_send_wr wr = {
368 .opcode = IB_WR_LOCAL_INV,
369 .wr_cqe = &req->inv_cqe,
370 .send_flags = IB_SEND_SIGNALED,
371 .ex.invalidate_rkey = req->mr->rkey,
372 };
373 req->inv_cqe.done = rtrs_clt_inv_rkey_done;
374
375 return ib_post_send(con->c.qp, &wr, NULL);
376 }
377
complete_rdma_req(struct rtrs_clt_io_req * req,int errno,bool notify,bool can_wait)378 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
379 bool notify, bool can_wait)
380 {
381 struct rtrs_clt_con *con = req->con;
382 struct rtrs_clt_path *clt_path;
383 int err;
384
385 if (WARN_ON(!req->in_use))
386 return;
387 if (WARN_ON(!req->con))
388 return;
389 clt_path = to_clt_path(con->c.path);
390
391 if (req->sg_cnt) {
392 if (req->dir == DMA_FROM_DEVICE && req->need_inv) {
393 /*
394 * We are here to invalidate read requests
395 * ourselves. In normal scenario server should
396 * send INV for all read requests, but
397 * we are here, thus two things could happen:
398 *
399 * 1. this is failover, when errno != 0
400 * and can_wait == 1,
401 *
402 * 2. something totally bad happened and
403 * server forgot to send INV, so we
404 * should do that ourselves.
405 */
406
407 if (can_wait) {
408 req->need_inv_comp = true;
409 } else {
410 /* This should be IO path, so always notify */
411 WARN_ON(!notify);
412 /* Save errno for INV callback */
413 req->inv_errno = errno;
414 }
415
416 refcount_inc(&req->ref);
417 err = rtrs_inv_rkey(req);
418 if (err) {
419 rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n",
420 req->mr->rkey, err);
421 } else if (can_wait) {
422 wait_for_completion(&req->inv_comp);
423 } else {
424 /*
425 * Something went wrong, so request will be
426 * completed from INV callback.
427 */
428 WARN_ON_ONCE(1);
429
430 return;
431 }
432 if (!refcount_dec_and_test(&req->ref))
433 return;
434 }
435 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
436 req->sg_cnt, req->dir);
437 }
438 if (!refcount_dec_and_test(&req->ref))
439 return;
440 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
441 atomic_dec(&clt_path->stats->inflight);
442
443 req->in_use = false;
444 req->con = NULL;
445
446 if (errno) {
447 rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n",
448 errno, kobject_name(&clt_path->kobj), clt_path->hca_name,
449 clt_path->hca_port, notify);
450 }
451
452 if (notify)
453 req->conf(req->priv, errno);
454 }
455
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)456 static int rtrs_post_send_rdma(struct rtrs_clt_con *con,
457 struct rtrs_clt_io_req *req,
458 struct rtrs_rbuf *rbuf, u32 off,
459 u32 imm, struct ib_send_wr *wr)
460 {
461 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
462 enum ib_send_flags flags;
463 struct ib_sge sge;
464
465 if (!req->sg_size) {
466 rtrs_wrn(con->c.path,
467 "Doing RDMA Write failed, no data supplied\n");
468 return -EINVAL;
469 }
470
471 /* user data and user message in the first list element */
472 sge.addr = req->iu->dma_addr;
473 sge.length = req->sg_size;
474 sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
475
476 /*
477 * From time to time we have to post signalled sends,
478 * or send queue will fill up and only QP reset can help.
479 */
480 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
481 0 : IB_SEND_SIGNALED;
482
483 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
484 req->iu->dma_addr,
485 req->sg_size, DMA_TO_DEVICE);
486
487 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1,
488 rbuf->rkey, rbuf->addr + off,
489 imm, flags, wr, NULL);
490 }
491
process_io_rsp(struct rtrs_clt_path * clt_path,u32 msg_id,s16 errno,bool w_inval)492 static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id,
493 s16 errno, bool w_inval)
494 {
495 struct rtrs_clt_io_req *req;
496
497 if (WARN_ON(msg_id >= clt_path->queue_depth))
498 return;
499
500 req = &clt_path->reqs[msg_id];
501 /* Drop need_inv if server responded with send with invalidation */
502 req->need_inv &= !w_inval;
503 complete_rdma_req(req, errno, true, false);
504 }
505
rtrs_clt_recv_done(struct rtrs_clt_con * con,struct ib_wc * wc)506 static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc)
507 {
508 struct rtrs_iu *iu;
509 int err;
510 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
511
512 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0);
513 iu = container_of(wc->wr_cqe, struct rtrs_iu,
514 cqe);
515 err = rtrs_iu_post_recv(&con->c, iu);
516 if (err) {
517 rtrs_err(con->c.path, "post iu failed %d\n", err);
518 rtrs_rdma_error_recovery(con);
519 }
520 }
521
rtrs_clt_rkey_rsp_done(struct rtrs_clt_con * con,struct ib_wc * wc)522 static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc)
523 {
524 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
525 struct rtrs_msg_rkey_rsp *msg;
526 u32 imm_type, imm_payload;
527 bool w_inval = false;
528 struct rtrs_iu *iu;
529 u32 buf_id;
530 int err;
531
532 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0);
533
534 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
535
536 if (wc->byte_len < sizeof(*msg)) {
537 rtrs_err(con->c.path, "rkey response is malformed: size %d\n",
538 wc->byte_len);
539 goto out;
540 }
541 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
542 iu->size, DMA_FROM_DEVICE);
543 msg = iu->buf;
544 if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) {
545 rtrs_err(clt_path->clt,
546 "rkey response is malformed: type %d\n",
547 le16_to_cpu(msg->type));
548 goto out;
549 }
550 buf_id = le16_to_cpu(msg->buf_id);
551 if (WARN_ON(buf_id >= clt_path->queue_depth))
552 goto out;
553
554 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload);
555 if (imm_type == RTRS_IO_RSP_IMM ||
556 imm_type == RTRS_IO_RSP_W_INV_IMM) {
557 u32 msg_id;
558
559 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
560 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
561
562 if (WARN_ON(buf_id != msg_id))
563 goto out;
564 clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey);
565 process_io_rsp(clt_path, msg_id, err, w_inval);
566 }
567 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr,
568 iu->size, DMA_FROM_DEVICE);
569 return rtrs_clt_recv_done(con, wc);
570 out:
571 rtrs_rdma_error_recovery(con);
572 }
573
574 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
575
576 static struct ib_cqe io_comp_cqe = {
577 .done = rtrs_clt_rdma_done
578 };
579
580 /*
581 * Post x2 empty WRs: first is for this RDMA with IMM,
582 * second is for RECV with INV, which happened earlier.
583 */
rtrs_post_recv_empty_x2(struct rtrs_con * con,struct ib_cqe * cqe)584 static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe)
585 {
586 struct ib_recv_wr wr_arr[2], *wr;
587 int i;
588
589 memset(wr_arr, 0, sizeof(wr_arr));
590 for (i = 0; i < ARRAY_SIZE(wr_arr); i++) {
591 wr = &wr_arr[i];
592 wr->wr_cqe = cqe;
593 if (i)
594 /* Chain backwards */
595 wr->next = &wr_arr[i - 1];
596 }
597
598 return ib_post_recv(con->qp, wr, NULL);
599 }
600
rtrs_clt_rdma_done(struct ib_cq * cq,struct ib_wc * wc)601 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
602 {
603 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
604 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
605 u32 imm_type, imm_payload;
606 bool w_inval = false;
607 int err;
608
609 if (wc->status != IB_WC_SUCCESS) {
610 if (wc->status != IB_WC_WR_FLUSH_ERR) {
611 rtrs_err(clt_path->clt, "RDMA failed: %s\n",
612 ib_wc_status_msg(wc->status));
613 rtrs_rdma_error_recovery(con);
614 }
615 return;
616 }
617 rtrs_clt_update_wc_stats(con);
618
619 switch (wc->opcode) {
620 case IB_WC_RECV_RDMA_WITH_IMM:
621 /*
622 * post_recv() RDMA write completions of IO reqs (read/write)
623 * and hb
624 */
625 if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done))
626 return;
627 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
628 &imm_type, &imm_payload);
629 if (imm_type == RTRS_IO_RSP_IMM ||
630 imm_type == RTRS_IO_RSP_W_INV_IMM) {
631 u32 msg_id;
632
633 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
634 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
635
636 process_io_rsp(clt_path, msg_id, err, w_inval);
637 } else if (imm_type == RTRS_HB_MSG_IMM) {
638 WARN_ON(con->c.cid);
639 rtrs_send_hb_ack(&clt_path->s);
640 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
641 return rtrs_clt_recv_done(con, wc);
642 } else if (imm_type == RTRS_HB_ACK_IMM) {
643 WARN_ON(con->c.cid);
644 clt_path->s.hb_missed_cnt = 0;
645 clt_path->s.hb_cur_latency =
646 ktime_sub(ktime_get(), clt_path->s.hb_last_sent);
647 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F)
648 return rtrs_clt_recv_done(con, wc);
649 } else {
650 rtrs_wrn(con->c.path, "Unknown IMM type %u\n",
651 imm_type);
652 }
653 if (w_inval)
654 /*
655 * Post x2 empty WRs: first is for this RDMA with IMM,
656 * second is for RECV with INV, which happened earlier.
657 */
658 err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe);
659 else
660 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
661 if (err) {
662 rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n",
663 err);
664 rtrs_rdma_error_recovery(con);
665 }
666 break;
667 case IB_WC_RECV:
668 /*
669 * Key invalidations from server side
670 */
671 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE ||
672 wc->wc_flags & IB_WC_WITH_IMM));
673 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done);
674 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
675 if (wc->wc_flags & IB_WC_WITH_INVALIDATE)
676 return rtrs_clt_recv_done(con, wc);
677
678 return rtrs_clt_rkey_rsp_done(con, wc);
679 }
680 break;
681 case IB_WC_RDMA_WRITE:
682 /*
683 * post_send() RDMA write completions of IO reqs (read/write)
684 * and hb.
685 */
686 break;
687
688 default:
689 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode);
690 return;
691 }
692 }
693
post_recv_io(struct rtrs_clt_con * con,size_t q_size)694 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size)
695 {
696 int err, i;
697 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
698
699 for (i = 0; i < q_size; i++) {
700 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) {
701 struct rtrs_iu *iu = &con->rsp_ius[i];
702
703 err = rtrs_iu_post_recv(&con->c, iu);
704 } else {
705 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
706 }
707 if (err)
708 return err;
709 }
710
711 return 0;
712 }
713
post_recv_path(struct rtrs_clt_path * clt_path)714 static int post_recv_path(struct rtrs_clt_path *clt_path)
715 {
716 size_t q_size = 0;
717 int err, cid;
718
719 for (cid = 0; cid < clt_path->s.con_num; cid++) {
720 if (cid == 0)
721 q_size = SERVICE_CON_QUEUE_DEPTH;
722 else
723 q_size = clt_path->queue_depth;
724
725 /*
726 * x2 for RDMA read responses + FR key invalidations,
727 * RDMA writes do not require any FR registrations.
728 */
729 q_size *= 2;
730
731 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size);
732 if (err) {
733 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n",
734 err);
735 return err;
736 }
737 }
738
739 return 0;
740 }
741
742 struct path_it {
743 int i;
744 struct list_head skip_list;
745 struct rtrs_clt_sess *clt;
746 struct rtrs_clt_path *(*next_path)(struct path_it *it);
747 };
748
749 /*
750 * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL
751 * @head: the head for the list.
752 * @clt_path: The element to take the next clt_path from.
753 *
754 * Next clt path returned in round-robin fashion, i.e. head will be skipped,
755 * but if list is observed as empty, NULL will be returned.
756 *
757 * This function may safely run concurrently with the _rcu list-mutation
758 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
759 */
760 static inline struct rtrs_clt_path *
rtrs_clt_get_next_path_or_null(struct list_head * head,struct rtrs_clt_path * clt_path)761 rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path)
762 {
763 return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?:
764 list_next_or_null_rcu(head,
765 READ_ONCE((&clt_path->s.entry)->next),
766 typeof(*clt_path), s.entry);
767 }
768
769 /**
770 * get_next_path_rr() - Returns path in round-robin fashion.
771 * @it: the path pointer
772 *
773 * Related to @MP_POLICY_RR
774 *
775 * Locks:
776 * rcu_read_lock() must be hold.
777 */
get_next_path_rr(struct path_it * it)778 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it)
779 {
780 struct rtrs_clt_path __rcu **ppcpu_path;
781 struct rtrs_clt_path *path;
782 struct rtrs_clt_sess *clt;
783
784 clt = it->clt;
785
786 /*
787 * Here we use two RCU objects: @paths_list and @pcpu_path
788 * pointer. See rtrs_clt_remove_path_from_arr() for details
789 * how that is handled.
790 */
791
792 ppcpu_path = this_cpu_ptr(clt->pcpu_path);
793 path = rcu_dereference(*ppcpu_path);
794 if (!path)
795 path = list_first_or_null_rcu(&clt->paths_list,
796 typeof(*path), s.entry);
797 else
798 path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path);
799
800 rcu_assign_pointer(*ppcpu_path, path);
801
802 return path;
803 }
804
805 /**
806 * get_next_path_min_inflight() - Returns path with minimal inflight count.
807 * @it: the path pointer
808 *
809 * Related to @MP_POLICY_MIN_INFLIGHT
810 *
811 * Locks:
812 * rcu_read_lock() must be hold.
813 */
get_next_path_min_inflight(struct path_it * it)814 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it)
815 {
816 struct rtrs_clt_path *min_path = NULL;
817 struct rtrs_clt_sess *clt = it->clt;
818 struct rtrs_clt_path *clt_path;
819 int min_inflight = INT_MAX;
820 int inflight;
821
822 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
823 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
824 continue;
825
826 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
827 continue;
828
829 inflight = atomic_read(&clt_path->stats->inflight);
830
831 if (inflight < min_inflight) {
832 min_inflight = inflight;
833 min_path = clt_path;
834 }
835 }
836
837 /*
838 * add the path to the skip list, so that next time we can get
839 * a different one
840 */
841 if (min_path)
842 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
843
844 return min_path;
845 }
846
847 /**
848 * get_next_path_min_latency() - Returns path with minimal latency.
849 * @it: the path pointer
850 *
851 * Return: a path with the lowest latency or NULL if all paths are tried
852 *
853 * Locks:
854 * rcu_read_lock() must be hold.
855 *
856 * Related to @MP_POLICY_MIN_LATENCY
857 *
858 * This DOES skip an already-tried path.
859 * There is a skip-list to skip a path if the path has tried but failed.
860 * It will try the minimum latency path and then the second minimum latency
861 * path and so on. Finally it will return NULL if all paths are tried.
862 * Therefore the caller MUST check the returned
863 * path is NULL and trigger the IO error.
864 */
get_next_path_min_latency(struct path_it * it)865 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it)
866 {
867 struct rtrs_clt_path *min_path = NULL;
868 struct rtrs_clt_sess *clt = it->clt;
869 struct rtrs_clt_path *clt_path;
870 ktime_t min_latency = KTIME_MAX;
871 ktime_t latency;
872
873 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) {
874 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
875 continue;
876
877 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry)))
878 continue;
879
880 latency = clt_path->s.hb_cur_latency;
881
882 if (latency < min_latency) {
883 min_latency = latency;
884 min_path = clt_path;
885 }
886 }
887
888 /*
889 * add the path to the skip list, so that next time we can get
890 * a different one
891 */
892 if (min_path)
893 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
894
895 return min_path;
896 }
897
path_it_init(struct path_it * it,struct rtrs_clt_sess * clt)898 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt)
899 {
900 INIT_LIST_HEAD(&it->skip_list);
901 it->clt = clt;
902 it->i = 0;
903
904 if (clt->mp_policy == MP_POLICY_RR)
905 it->next_path = get_next_path_rr;
906 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
907 it->next_path = get_next_path_min_inflight;
908 else
909 it->next_path = get_next_path_min_latency;
910 }
911
path_it_deinit(struct path_it * it)912 static inline void path_it_deinit(struct path_it *it)
913 {
914 struct list_head *skip, *tmp;
915 /*
916 * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies.
917 * We need to remove paths from it, so that next IO can insert
918 * paths (->mp_skip_entry) into a skip_list again.
919 */
920 list_for_each_safe(skip, tmp, &it->skip_list)
921 list_del_init(skip);
922 }
923
924 /**
925 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information
926 * about an inflight IO.
927 * The user buffer holding user control message (not data) is copied into
928 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will
929 * also hold the control message of rtrs.
930 * @req: an io request holding information about IO.
931 * @clt_path: client path
932 * @conf: conformation callback function to notify upper layer.
933 * @permit: permit for allocation of RDMA remote buffer
934 * @priv: private pointer
935 * @vec: kernel vector containing control message
936 * @usr_len: length of the user message
937 * @sg: scater list for IO data
938 * @sg_cnt: number of scater list entries
939 * @data_len: length of the IO data
940 * @dir: direction of the IO.
941 */
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)942 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
943 struct rtrs_clt_path *clt_path,
944 void (*conf)(void *priv, int errno),
945 struct rtrs_permit *permit, void *priv,
946 const struct kvec *vec, size_t usr_len,
947 struct scatterlist *sg, size_t sg_cnt,
948 size_t data_len, int dir)
949 {
950 struct iov_iter iter;
951 size_t len;
952
953 req->permit = permit;
954 req->in_use = true;
955 req->usr_len = usr_len;
956 req->data_len = data_len;
957 req->sglist = sg;
958 req->sg_cnt = sg_cnt;
959 req->priv = priv;
960 req->dir = dir;
961 req->con = rtrs_permit_to_clt_con(clt_path, permit);
962 req->conf = conf;
963 req->need_inv = false;
964 req->need_inv_comp = false;
965 req->inv_errno = 0;
966 refcount_set(&req->ref, 1);
967 req->mp_policy = clt_path->clt->mp_policy;
968
969 iov_iter_kvec(&iter, READ, vec, 1, usr_len);
970 len = _copy_from_iter(req->iu->buf, usr_len, &iter);
971 WARN_ON(len != usr_len);
972
973 reinit_completion(&req->inv_comp);
974 }
975
976 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)977 rtrs_clt_get_req(struct rtrs_clt_path *clt_path,
978 void (*conf)(void *priv, int errno),
979 struct rtrs_permit *permit, void *priv,
980 const struct kvec *vec, size_t usr_len,
981 struct scatterlist *sg, size_t sg_cnt,
982 size_t data_len, int dir)
983 {
984 struct rtrs_clt_io_req *req;
985
986 req = &clt_path->reqs[permit->mem_id];
987 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len,
988 sg, sg_cnt, data_len, dir);
989 return req;
990 }
991
992 static struct rtrs_clt_io_req *
rtrs_clt_get_copy_req(struct rtrs_clt_path * alive_path,struct rtrs_clt_io_req * fail_req)993 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path,
994 struct rtrs_clt_io_req *fail_req)
995 {
996 struct rtrs_clt_io_req *req;
997 struct kvec vec = {
998 .iov_base = fail_req->iu->buf,
999 .iov_len = fail_req->usr_len
1000 };
1001
1002 req = &alive_path->reqs[fail_req->permit->mem_id];
1003 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit,
1004 fail_req->priv, &vec, fail_req->usr_len,
1005 fail_req->sglist, fail_req->sg_cnt,
1006 fail_req->data_len, fail_req->dir);
1007 return req;
1008 }
1009
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)1010 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
1011 struct rtrs_clt_io_req *req,
1012 struct rtrs_rbuf *rbuf, bool fr_en,
1013 u32 count, u32 size, u32 imm,
1014 struct ib_send_wr *wr,
1015 struct ib_send_wr *tail)
1016 {
1017 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1018 struct ib_sge *sge = req->sge;
1019 enum ib_send_flags flags;
1020 struct scatterlist *sg;
1021 size_t num_sge;
1022 int i;
1023 struct ib_send_wr *ptail = NULL;
1024
1025 if (fr_en) {
1026 i = 0;
1027 sge[i].addr = req->mr->iova;
1028 sge[i].length = req->mr->length;
1029 sge[i].lkey = req->mr->lkey;
1030 i++;
1031 num_sge = 2;
1032 ptail = tail;
1033 } else {
1034 for_each_sg(req->sglist, sg, count, i) {
1035 sge[i].addr = sg_dma_address(sg);
1036 sge[i].length = sg_dma_len(sg);
1037 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
1038 }
1039 num_sge = 1 + count;
1040 }
1041 sge[i].addr = req->iu->dma_addr;
1042 sge[i].length = size;
1043 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey;
1044
1045 /*
1046 * From time to time we have to post signalled sends,
1047 * or send queue will fill up and only QP reset can help.
1048 */
1049 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ?
1050 0 : IB_SEND_SIGNALED;
1051
1052 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
1053 req->iu->dma_addr,
1054 size, DMA_TO_DEVICE);
1055
1056 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
1057 rbuf->rkey, rbuf->addr, imm,
1058 flags, wr, ptail);
1059 }
1060
rtrs_map_sg_fr(struct rtrs_clt_io_req * req,size_t count)1061 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
1062 {
1063 int nr;
1064
1065 /* Align the MR to a 4K page size to match the block virt boundary */
1066 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
1067 if (nr < 0)
1068 return nr;
1069 if (nr < req->sg_cnt)
1070 return -EINVAL;
1071 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
1072
1073 return nr;
1074 }
1075
rtrs_clt_write_req(struct rtrs_clt_io_req * req)1076 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
1077 {
1078 struct rtrs_clt_con *con = req->con;
1079 struct rtrs_path *s = con->c.path;
1080 struct rtrs_clt_path *clt_path = to_clt_path(s);
1081 struct rtrs_msg_rdma_write *msg;
1082
1083 struct rtrs_rbuf *rbuf;
1084 int ret, count = 0;
1085 u32 imm, buf_id;
1086 struct ib_reg_wr rwr;
1087 struct ib_send_wr inv_wr;
1088 struct ib_send_wr *wr = NULL;
1089 bool fr_en = false;
1090
1091 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
1092
1093 if (tsize > clt_path->chunk_size) {
1094 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n",
1095 tsize, clt_path->chunk_size);
1096 return -EMSGSIZE;
1097 }
1098 if (req->sg_cnt) {
1099 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist,
1100 req->sg_cnt, req->dir);
1101 if (!count) {
1102 rtrs_wrn(s, "Write request failed, map failed\n");
1103 return -EINVAL;
1104 }
1105 }
1106 /* put rtrs msg after sg and user message */
1107 msg = req->iu->buf + req->usr_len;
1108 msg->type = cpu_to_le16(RTRS_MSG_WRITE);
1109 msg->usr_len = cpu_to_le16(req->usr_len);
1110
1111 /* rtrs message on server side will be after user data and message */
1112 imm = req->permit->mem_off + req->data_len + req->usr_len;
1113 imm = rtrs_to_io_req_imm(imm);
1114 buf_id = req->permit->mem_id;
1115 req->sg_size = tsize;
1116 rbuf = &clt_path->rbufs[buf_id];
1117
1118 if (count) {
1119 ret = rtrs_map_sg_fr(req, count);
1120 if (ret < 0) {
1121 rtrs_err_rl(s,
1122 "Write request failed, failed to map fast reg. data, err: %d\n",
1123 ret);
1124 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
1125 req->sg_cnt, req->dir);
1126 return ret;
1127 }
1128 inv_wr = (struct ib_send_wr) {
1129 .opcode = IB_WR_LOCAL_INV,
1130 .wr_cqe = &req->inv_cqe,
1131 .send_flags = IB_SEND_SIGNALED,
1132 .ex.invalidate_rkey = req->mr->rkey,
1133 };
1134 req->inv_cqe.done = rtrs_clt_inv_rkey_done;
1135 rwr = (struct ib_reg_wr) {
1136 .wr.opcode = IB_WR_REG_MR,
1137 .wr.wr_cqe = &fast_reg_cqe,
1138 .mr = req->mr,
1139 .key = req->mr->rkey,
1140 .access = (IB_ACCESS_LOCAL_WRITE),
1141 };
1142 wr = &rwr.wr;
1143 fr_en = true;
1144 refcount_inc(&req->ref);
1145 }
1146 /*
1147 * Update stats now, after request is successfully sent it is not
1148 * safe anymore to touch it.
1149 */
1150 rtrs_clt_update_all_stats(req, WRITE);
1151
1152 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count,
1153 req->usr_len + sizeof(*msg),
1154 imm, wr, &inv_wr);
1155 if (ret) {
1156 rtrs_err_rl(s,
1157 "Write request failed: error=%d path=%s [%s:%u]\n",
1158 ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
1159 clt_path->hca_port);
1160 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
1161 atomic_dec(&clt_path->stats->inflight);
1162 if (req->sg_cnt)
1163 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist,
1164 req->sg_cnt, req->dir);
1165 }
1166
1167 return ret;
1168 }
1169
rtrs_clt_read_req(struct rtrs_clt_io_req * req)1170 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req)
1171 {
1172 struct rtrs_clt_con *con = req->con;
1173 struct rtrs_path *s = con->c.path;
1174 struct rtrs_clt_path *clt_path = to_clt_path(s);
1175 struct rtrs_msg_rdma_read *msg;
1176 struct rtrs_ib_dev *dev = clt_path->s.dev;
1177
1178 struct ib_reg_wr rwr;
1179 struct ib_send_wr *wr = NULL;
1180
1181 int ret, count = 0;
1182 u32 imm, buf_id;
1183
1184 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
1185
1186 if (tsize > clt_path->chunk_size) {
1187 rtrs_wrn(s,
1188 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n",
1189 tsize, clt_path->chunk_size);
1190 return -EMSGSIZE;
1191 }
1192
1193 if (req->sg_cnt) {
1194 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt,
1195 req->dir);
1196 if (!count) {
1197 rtrs_wrn(s,
1198 "Read request failed, dma map failed\n");
1199 return -EINVAL;
1200 }
1201 }
1202 /* put our message into req->buf after user message*/
1203 msg = req->iu->buf + req->usr_len;
1204 msg->type = cpu_to_le16(RTRS_MSG_READ);
1205 msg->usr_len = cpu_to_le16(req->usr_len);
1206
1207 if (count) {
1208 ret = rtrs_map_sg_fr(req, count);
1209 if (ret < 0) {
1210 rtrs_err_rl(s,
1211 "Read request failed, failed to map fast reg. data, err: %d\n",
1212 ret);
1213 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt,
1214 req->dir);
1215 return ret;
1216 }
1217 rwr = (struct ib_reg_wr) {
1218 .wr.opcode = IB_WR_REG_MR,
1219 .wr.wr_cqe = &fast_reg_cqe,
1220 .mr = req->mr,
1221 .key = req->mr->rkey,
1222 .access = (IB_ACCESS_LOCAL_WRITE |
1223 IB_ACCESS_REMOTE_WRITE),
1224 };
1225 wr = &rwr.wr;
1226
1227 msg->sg_cnt = cpu_to_le16(1);
1228 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F);
1229
1230 msg->desc[0].addr = cpu_to_le64(req->mr->iova);
1231 msg->desc[0].key = cpu_to_le32(req->mr->rkey);
1232 msg->desc[0].len = cpu_to_le32(req->mr->length);
1233
1234 /* Further invalidation is required */
1235 req->need_inv = !!RTRS_MSG_NEED_INVAL_F;
1236
1237 } else {
1238 msg->sg_cnt = 0;
1239 msg->flags = 0;
1240 }
1241 /*
1242 * rtrs message will be after the space reserved for disk data and
1243 * user message
1244 */
1245 imm = req->permit->mem_off + req->data_len + req->usr_len;
1246 imm = rtrs_to_io_req_imm(imm);
1247 buf_id = req->permit->mem_id;
1248
1249 req->sg_size = sizeof(*msg);
1250 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc);
1251 req->sg_size += req->usr_len;
1252
1253 /*
1254 * Update stats now, after request is successfully sent it is not
1255 * safe anymore to touch it.
1256 */
1257 rtrs_clt_update_all_stats(req, READ);
1258
1259 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id],
1260 req->data_len, imm, wr);
1261 if (ret) {
1262 rtrs_err_rl(s,
1263 "Read request failed: error=%d path=%s [%s:%u]\n",
1264 ret, kobject_name(&clt_path->kobj), clt_path->hca_name,
1265 clt_path->hca_port);
1266 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT)
1267 atomic_dec(&clt_path->stats->inflight);
1268 req->need_inv = false;
1269 if (req->sg_cnt)
1270 ib_dma_unmap_sg(dev->ib_dev, req->sglist,
1271 req->sg_cnt, req->dir);
1272 }
1273
1274 return ret;
1275 }
1276
1277 /**
1278 * rtrs_clt_failover_req() - Try to find an active path for a failed request
1279 * @clt: clt context
1280 * @fail_req: a failed io request.
1281 */
rtrs_clt_failover_req(struct rtrs_clt_sess * clt,struct rtrs_clt_io_req * fail_req)1282 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt,
1283 struct rtrs_clt_io_req *fail_req)
1284 {
1285 struct rtrs_clt_path *alive_path;
1286 struct rtrs_clt_io_req *req;
1287 int err = -ECONNABORTED;
1288 struct path_it it;
1289
1290 rcu_read_lock();
1291 for (path_it_init(&it, clt);
1292 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num;
1293 it.i++) {
1294 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED)
1295 continue;
1296 req = rtrs_clt_get_copy_req(alive_path, fail_req);
1297 if (req->dir == DMA_TO_DEVICE)
1298 err = rtrs_clt_write_req(req);
1299 else
1300 err = rtrs_clt_read_req(req);
1301 if (err) {
1302 req->in_use = false;
1303 continue;
1304 }
1305 /* Success path */
1306 rtrs_clt_inc_failover_cnt(alive_path->stats);
1307 break;
1308 }
1309 path_it_deinit(&it);
1310 rcu_read_unlock();
1311
1312 return err;
1313 }
1314
fail_all_outstanding_reqs(struct rtrs_clt_path * clt_path)1315 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path)
1316 {
1317 struct rtrs_clt_sess *clt = clt_path->clt;
1318 struct rtrs_clt_io_req *req;
1319 int i, err;
1320
1321 if (!clt_path->reqs)
1322 return;
1323 for (i = 0; i < clt_path->queue_depth; ++i) {
1324 req = &clt_path->reqs[i];
1325 if (!req->in_use)
1326 continue;
1327
1328 /*
1329 * Safely (without notification) complete failed request.
1330 * After completion this request is still useble and can
1331 * be failovered to another path.
1332 */
1333 complete_rdma_req(req, -ECONNABORTED, false, true);
1334
1335 err = rtrs_clt_failover_req(clt, req);
1336 if (err)
1337 /* Failover failed, notify anyway */
1338 req->conf(req->priv, err);
1339 }
1340 }
1341
free_path_reqs(struct rtrs_clt_path * clt_path)1342 static void free_path_reqs(struct rtrs_clt_path *clt_path)
1343 {
1344 struct rtrs_clt_io_req *req;
1345 int i;
1346
1347 if (!clt_path->reqs)
1348 return;
1349 for (i = 0; i < clt_path->queue_depth; ++i) {
1350 req = &clt_path->reqs[i];
1351 if (req->mr)
1352 ib_dereg_mr(req->mr);
1353 kfree(req->sge);
1354 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1);
1355 }
1356 kfree(clt_path->reqs);
1357 clt_path->reqs = NULL;
1358 }
1359
alloc_path_reqs(struct rtrs_clt_path * clt_path)1360 static int alloc_path_reqs(struct rtrs_clt_path *clt_path)
1361 {
1362 struct rtrs_clt_io_req *req;
1363 int i, err = -ENOMEM;
1364
1365 clt_path->reqs = kcalloc(clt_path->queue_depth,
1366 sizeof(*clt_path->reqs),
1367 GFP_KERNEL);
1368 if (!clt_path->reqs)
1369 return -ENOMEM;
1370
1371 for (i = 0; i < clt_path->queue_depth; ++i) {
1372 req = &clt_path->reqs[i];
1373 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL,
1374 clt_path->s.dev->ib_dev,
1375 DMA_TO_DEVICE,
1376 rtrs_clt_rdma_done);
1377 if (!req->iu)
1378 goto out;
1379
1380 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL);
1381 if (!req->sge)
1382 goto out;
1383
1384 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd,
1385 IB_MR_TYPE_MEM_REG,
1386 clt_path->max_pages_per_mr);
1387 if (IS_ERR(req->mr)) {
1388 err = PTR_ERR(req->mr);
1389 req->mr = NULL;
1390 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n",
1391 clt_path->max_pages_per_mr);
1392 goto out;
1393 }
1394
1395 init_completion(&req->inv_comp);
1396 }
1397
1398 return 0;
1399
1400 out:
1401 free_path_reqs(clt_path);
1402
1403 return err;
1404 }
1405
alloc_permits(struct rtrs_clt_sess * clt)1406 static int alloc_permits(struct rtrs_clt_sess *clt)
1407 {
1408 unsigned int chunk_bits;
1409 int err, i;
1410
1411 clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL);
1412 if (!clt->permits_map) {
1413 err = -ENOMEM;
1414 goto out_err;
1415 }
1416 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL);
1417 if (!clt->permits) {
1418 err = -ENOMEM;
1419 goto err_map;
1420 }
1421 chunk_bits = ilog2(clt->queue_depth - 1) + 1;
1422 for (i = 0; i < clt->queue_depth; i++) {
1423 struct rtrs_permit *permit;
1424
1425 permit = get_permit(clt, i);
1426 permit->mem_id = i;
1427 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits);
1428 }
1429
1430 return 0;
1431
1432 err_map:
1433 bitmap_free(clt->permits_map);
1434 clt->permits_map = NULL;
1435 out_err:
1436 return err;
1437 }
1438
free_permits(struct rtrs_clt_sess * clt)1439 static void free_permits(struct rtrs_clt_sess *clt)
1440 {
1441 if (clt->permits_map)
1442 wait_event(clt->permits_wait,
1443 bitmap_empty(clt->permits_map, clt->queue_depth));
1444
1445 bitmap_free(clt->permits_map);
1446 clt->permits_map = NULL;
1447 kfree(clt->permits);
1448 clt->permits = NULL;
1449 }
1450
query_fast_reg_mode(struct rtrs_clt_path * clt_path)1451 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path)
1452 {
1453 struct ib_device *ib_dev;
1454 u64 max_pages_per_mr;
1455 int mr_page_shift;
1456
1457 ib_dev = clt_path->s.dev->ib_dev;
1458
1459 /*
1460 * Use the smallest page size supported by the HCA, down to a
1461 * minimum of 4096 bytes. We're unlikely to build large sglists
1462 * out of smaller entries.
1463 */
1464 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1);
1465 max_pages_per_mr = ib_dev->attrs.max_mr_size;
1466 do_div(max_pages_per_mr, (1ull << mr_page_shift));
1467 clt_path->max_pages_per_mr =
1468 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr,
1469 ib_dev->attrs.max_fast_reg_page_list_len);
1470 clt_path->clt->max_segments =
1471 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments);
1472 }
1473
rtrs_clt_change_state_get_old(struct rtrs_clt_path * clt_path,enum rtrs_clt_state new_state,enum rtrs_clt_state * old_state)1474 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path,
1475 enum rtrs_clt_state new_state,
1476 enum rtrs_clt_state *old_state)
1477 {
1478 bool changed;
1479
1480 spin_lock_irq(&clt_path->state_wq.lock);
1481 if (old_state)
1482 *old_state = clt_path->state;
1483 changed = rtrs_clt_change_state(clt_path, new_state);
1484 spin_unlock_irq(&clt_path->state_wq.lock);
1485
1486 return changed;
1487 }
1488
rtrs_clt_hb_err_handler(struct rtrs_con * c)1489 static void rtrs_clt_hb_err_handler(struct rtrs_con *c)
1490 {
1491 struct rtrs_clt_con *con = container_of(c, typeof(*con), c);
1492
1493 rtrs_rdma_error_recovery(con);
1494 }
1495
rtrs_clt_init_hb(struct rtrs_clt_path * clt_path)1496 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path)
1497 {
1498 rtrs_init_hb(&clt_path->s, &io_comp_cqe,
1499 RTRS_HB_INTERVAL_MS,
1500 RTRS_HB_MISSED_MAX,
1501 rtrs_clt_hb_err_handler,
1502 rtrs_wq);
1503 }
1504
1505 static void rtrs_clt_reconnect_work(struct work_struct *work);
1506 static void rtrs_clt_close_work(struct work_struct *work);
1507
rtrs_clt_err_recovery_work(struct work_struct * work)1508 static void rtrs_clt_err_recovery_work(struct work_struct *work)
1509 {
1510 struct rtrs_clt_path *clt_path;
1511 struct rtrs_clt_sess *clt;
1512 int delay_ms;
1513
1514 clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work);
1515 clt = clt_path->clt;
1516 delay_ms = clt->reconnect_delay_sec * 1000;
1517 rtrs_clt_stop_and_destroy_conns(clt_path);
1518 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
1519 msecs_to_jiffies(delay_ms +
1520 prandom_u32_max(RTRS_RECONNECT_SEED)));
1521 }
1522
alloc_path(struct rtrs_clt_sess * clt,const struct rtrs_addr * path,size_t con_num,u32 nr_poll_queues)1523 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
1524 const struct rtrs_addr *path,
1525 size_t con_num, u32 nr_poll_queues)
1526 {
1527 struct rtrs_clt_path *clt_path;
1528 int err = -ENOMEM;
1529 int cpu;
1530 size_t total_con;
1531
1532 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL);
1533 if (!clt_path)
1534 goto err;
1535
1536 /*
1537 * irqmode and poll
1538 * +1: Extra connection for user messages
1539 */
1540 total_con = con_num + nr_poll_queues + 1;
1541 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con),
1542 GFP_KERNEL);
1543 if (!clt_path->s.con)
1544 goto err_free_path;
1545
1546 clt_path->s.con_num = total_con;
1547 clt_path->s.irq_con_num = con_num + 1;
1548
1549 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL);
1550 if (!clt_path->stats)
1551 goto err_free_con;
1552
1553 mutex_init(&clt_path->init_mutex);
1554 uuid_gen(&clt_path->s.uuid);
1555 memcpy(&clt_path->s.dst_addr, path->dst,
1556 rdma_addr_size((struct sockaddr *)path->dst));
1557
1558 /*
1559 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which
1560 * checks the sa_family to be non-zero. If user passed src_addr=NULL
1561 * the sess->src_addr will contain only zeros, which is then fine.
1562 */
1563 if (path->src)
1564 memcpy(&clt_path->s.src_addr, path->src,
1565 rdma_addr_size((struct sockaddr *)path->src));
1566 strscpy(clt_path->s.sessname, clt->sessname,
1567 sizeof(clt_path->s.sessname));
1568 clt_path->clt = clt;
1569 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS;
1570 init_waitqueue_head(&clt_path->state_wq);
1571 clt_path->state = RTRS_CLT_CONNECTING;
1572 atomic_set(&clt_path->connected_cnt, 0);
1573 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work);
1574 INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work);
1575 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work);
1576 rtrs_clt_init_hb(clt_path);
1577
1578 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry));
1579 if (!clt_path->mp_skip_entry)
1580 goto err_free_stats;
1581
1582 for_each_possible_cpu(cpu)
1583 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu));
1584
1585 err = rtrs_clt_init_stats(clt_path->stats);
1586 if (err)
1587 goto err_free_percpu;
1588
1589 return clt_path;
1590
1591 err_free_percpu:
1592 free_percpu(clt_path->mp_skip_entry);
1593 err_free_stats:
1594 kfree(clt_path->stats);
1595 err_free_con:
1596 kfree(clt_path->s.con);
1597 err_free_path:
1598 kfree(clt_path);
1599 err:
1600 return ERR_PTR(err);
1601 }
1602
free_path(struct rtrs_clt_path * clt_path)1603 void free_path(struct rtrs_clt_path *clt_path)
1604 {
1605 free_percpu(clt_path->mp_skip_entry);
1606 mutex_destroy(&clt_path->init_mutex);
1607 kfree(clt_path->s.con);
1608 kfree(clt_path->rbufs);
1609 kfree(clt_path);
1610 }
1611
create_con(struct rtrs_clt_path * clt_path,unsigned int cid)1612 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid)
1613 {
1614 struct rtrs_clt_con *con;
1615
1616 con = kzalloc(sizeof(*con), GFP_KERNEL);
1617 if (!con)
1618 return -ENOMEM;
1619
1620 /* Map first two connections to the first CPU */
1621 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids;
1622 con->c.cid = cid;
1623 con->c.path = &clt_path->s;
1624 /* Align with srv, init as 1 */
1625 atomic_set(&con->c.wr_cnt, 1);
1626 mutex_init(&con->con_mutex);
1627
1628 clt_path->s.con[cid] = &con->c;
1629
1630 return 0;
1631 }
1632
destroy_con(struct rtrs_clt_con * con)1633 static void destroy_con(struct rtrs_clt_con *con)
1634 {
1635 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1636
1637 clt_path->s.con[con->c.cid] = NULL;
1638 mutex_destroy(&con->con_mutex);
1639 kfree(con);
1640 }
1641
create_con_cq_qp(struct rtrs_clt_con * con)1642 static int create_con_cq_qp(struct rtrs_clt_con *con)
1643 {
1644 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
1645 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit;
1646 int err, cq_vector;
1647 struct rtrs_msg_rkey_rsp *rsp;
1648
1649 lockdep_assert_held(&con->con_mutex);
1650 if (con->c.cid == 0) {
1651 max_send_sge = 1;
1652 /* We must be the first here */
1653 if (WARN_ON(clt_path->s.dev))
1654 return -EINVAL;
1655
1656 /*
1657 * The whole session uses device from user connection.
1658 * Be careful not to close user connection before ib dev
1659 * is gracefully put.
1660 */
1661 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device,
1662 &dev_pd);
1663 if (!clt_path->s.dev) {
1664 rtrs_wrn(clt_path->clt,
1665 "rtrs_ib_dev_find_get_or_add(): no memory\n");
1666 return -ENOMEM;
1667 }
1668 clt_path->s.dev_ref = 1;
1669 query_fast_reg_mode(clt_path);
1670 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
1671 /*
1672 * Two (request + registration) completion for send
1673 * Two for recv if always_invalidate is set on server
1674 * or one for recv.
1675 * + 2 for drain and heartbeat
1676 * in case qp gets into error state.
1677 */
1678 max_send_wr =
1679 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2);
1680 max_recv_wr = max_send_wr;
1681 } else {
1682 /*
1683 * Here we assume that session members are correctly set.
1684 * This is always true if user connection (cid == 0) is
1685 * established first.
1686 */
1687 if (WARN_ON(!clt_path->s.dev))
1688 return -EINVAL;
1689 if (WARN_ON(!clt_path->queue_depth))
1690 return -EINVAL;
1691
1692 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr;
1693 /* Shared between connections */
1694 clt_path->s.dev_ref++;
1695 max_send_wr = min_t(int, wr_limit,
1696 /* QD * (REQ + RSP + FR REGS or INVS) + drain */
1697 clt_path->queue_depth * 3 + 1);
1698 max_recv_wr = min_t(int, wr_limit,
1699 clt_path->queue_depth * 3 + 1);
1700 max_send_sge = 2;
1701 }
1702 atomic_set(&con->c.sq_wr_avail, max_send_wr);
1703 cq_num = max_send_wr + max_recv_wr;
1704 /* alloc iu to recv new rkey reply when server reports flags set */
1705 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) {
1706 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp),
1707 GFP_KERNEL,
1708 clt_path->s.dev->ib_dev,
1709 DMA_FROM_DEVICE,
1710 rtrs_clt_rdma_done);
1711 if (!con->rsp_ius)
1712 return -ENOMEM;
1713 con->queue_num = cq_num;
1714 }
1715 cq_num = max_send_wr + max_recv_wr;
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
create_cm(struct rtrs_clt_con * con)2045 static int create_cm(struct rtrs_clt_con *con)
2046 {
2047 struct rtrs_path *s = con->c.path;
2048 struct rtrs_clt_path *clt_path = to_clt_path(s);
2049 struct rdma_cm_id *cm_id;
2050 int err;
2051
2052 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con,
2053 clt_path->s.dst_addr.ss_family == AF_IB ?
2054 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC);
2055 if (IS_ERR(cm_id)) {
2056 err = PTR_ERR(cm_id);
2057 rtrs_err(s, "Failed to create CM ID, err: %d\n", err);
2058
2059 return err;
2060 }
2061 con->c.cm_id = cm_id;
2062 con->cm_err = 0;
2063 /* allow the port to be reused */
2064 err = rdma_set_reuseaddr(cm_id, 1);
2065 if (err != 0) {
2066 rtrs_err(s, "Set address reuse failed, err: %d\n", err);
2067 goto destroy_cm;
2068 }
2069 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr,
2070 (struct sockaddr *)&clt_path->s.dst_addr,
2071 RTRS_CONNECT_TIMEOUT_MS);
2072 if (err) {
2073 rtrs_err(s, "Failed to resolve address, err: %d\n", err);
2074 goto destroy_cm;
2075 }
2076 /*
2077 * Combine connection status and session events. This is needed
2078 * for waiting two possible cases: cm_err has something meaningful
2079 * or session state was really changed to error by device removal.
2080 */
2081 err = wait_event_interruptible_timeout(
2082 clt_path->state_wq,
2083 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING,
2084 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
2085 if (err == 0 || err == -ERESTARTSYS) {
2086 if (err == 0)
2087 err = -ETIMEDOUT;
2088 /* Timedout or interrupted */
2089 goto errr;
2090 }
2091 if (con->cm_err < 0) {
2092 err = con->cm_err;
2093 goto errr;
2094 }
2095 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING) {
2096 /* Device removal */
2097 err = -ECONNABORTED;
2098 goto errr;
2099 }
2100
2101 return 0;
2102
2103 errr:
2104 stop_cm(con);
2105 mutex_lock(&con->con_mutex);
2106 destroy_con_cq_qp(con);
2107 mutex_unlock(&con->con_mutex);
2108 destroy_cm:
2109 destroy_cm(con);
2110
2111 return err;
2112 }
2113
rtrs_clt_path_up(struct rtrs_clt_path * clt_path)2114 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path)
2115 {
2116 struct rtrs_clt_sess *clt = clt_path->clt;
2117 int up;
2118
2119 /*
2120 * We can fire RECONNECTED event only when all paths were
2121 * connected on rtrs_clt_open(), then each was disconnected
2122 * and the first one connected again. That's why this nasty
2123 * game with counter value.
2124 */
2125
2126 mutex_lock(&clt->paths_ev_mutex);
2127 up = ++clt->paths_up;
2128 /*
2129 * Here it is safe to access paths num directly since up counter
2130 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is
2131 * in progress, thus paths removals are impossible.
2132 */
2133 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num)
2134 clt->paths_up = clt->paths_num;
2135 else if (up == 1)
2136 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED);
2137 mutex_unlock(&clt->paths_ev_mutex);
2138
2139 /* Mark session as established */
2140 clt_path->established = true;
2141 clt_path->reconnect_attempts = 0;
2142 clt_path->stats->reconnects.successful_cnt++;
2143 }
2144
rtrs_clt_path_down(struct rtrs_clt_path * clt_path)2145 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path)
2146 {
2147 struct rtrs_clt_sess *clt = clt_path->clt;
2148
2149 if (!clt_path->established)
2150 return;
2151
2152 clt_path->established = false;
2153 mutex_lock(&clt->paths_ev_mutex);
2154 WARN_ON(!clt->paths_up);
2155 if (--clt->paths_up == 0)
2156 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED);
2157 mutex_unlock(&clt->paths_ev_mutex);
2158 }
2159
rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path * clt_path)2160 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path)
2161 {
2162 struct rtrs_clt_con *con;
2163 unsigned int cid;
2164
2165 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED);
2166
2167 /*
2168 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes
2169 * exactly in between. Start destroying after it finishes.
2170 */
2171 mutex_lock(&clt_path->init_mutex);
2172 mutex_unlock(&clt_path->init_mutex);
2173
2174 /*
2175 * All IO paths must observe !CONNECTED state before we
2176 * free everything.
2177 */
2178 synchronize_rcu();
2179
2180 rtrs_stop_hb(&clt_path->s);
2181
2182 /*
2183 * The order it utterly crucial: firstly disconnect and complete all
2184 * rdma requests with error (thus set in_use=false for requests),
2185 * then fail outstanding requests checking in_use for each, and
2186 * eventually notify upper layer about session disconnection.
2187 */
2188
2189 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2190 if (!clt_path->s.con[cid])
2191 break;
2192 con = to_clt_con(clt_path->s.con[cid]);
2193 stop_cm(con);
2194 }
2195 fail_all_outstanding_reqs(clt_path);
2196 free_path_reqs(clt_path);
2197 rtrs_clt_path_down(clt_path);
2198
2199 /*
2200 * Wait for graceful shutdown, namely when peer side invokes
2201 * rdma_disconnect(). 'connected_cnt' is decremented only on
2202 * CM events, thus if other side had crashed and hb has detected
2203 * something is wrong, here we will stuck for exactly timeout ms,
2204 * since CM does not fire anything. That is fine, we are not in
2205 * hurry.
2206 */
2207 wait_event_timeout(clt_path->state_wq,
2208 !atomic_read(&clt_path->connected_cnt),
2209 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS));
2210
2211 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2212 if (!clt_path->s.con[cid])
2213 break;
2214 con = to_clt_con(clt_path->s.con[cid]);
2215 mutex_lock(&con->con_mutex);
2216 destroy_con_cq_qp(con);
2217 mutex_unlock(&con->con_mutex);
2218 destroy_cm(con);
2219 destroy_con(con);
2220 }
2221 }
2222
rtrs_clt_remove_path_from_arr(struct rtrs_clt_path * clt_path)2223 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path)
2224 {
2225 struct rtrs_clt_sess *clt = clt_path->clt;
2226 struct rtrs_clt_path *next;
2227 bool wait_for_grace = false;
2228 int cpu;
2229
2230 mutex_lock(&clt->paths_mutex);
2231 list_del_rcu(&clt_path->s.entry);
2232
2233 /* Make sure everybody observes path removal. */
2234 synchronize_rcu();
2235
2236 /*
2237 * At this point nobody sees @sess in the list, but still we have
2238 * dangling pointer @pcpu_path which _can_ point to @sess. Since
2239 * nobody can observe @sess in the list, we guarantee that IO path
2240 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal
2241 * to @sess, but can never again become @sess.
2242 */
2243
2244 /*
2245 * Decrement paths number only after grace period, because
2246 * caller of do_each_path() must firstly observe list without
2247 * path and only then decremented paths number.
2248 *
2249 * Otherwise there can be the following situation:
2250 * o Two paths exist and IO is coming.
2251 * o One path is removed:
2252 * CPU#0 CPU#1
2253 * do_each_path(): rtrs_clt_remove_path_from_arr():
2254 * path = get_next_path()
2255 * ^^^ list_del_rcu(path)
2256 * [!CONNECTED path] clt->paths_num--
2257 * ^^^^^^^^^
2258 * load clt->paths_num from 2 to 1
2259 * ^^^^^^^^^
2260 * sees 1
2261 *
2262 * path is observed as !CONNECTED, but do_each_path() loop
2263 * ends, because expression i < clt->paths_num is false.
2264 */
2265 clt->paths_num--;
2266
2267 /*
2268 * Get @next connection from current @sess which is going to be
2269 * removed. If @sess is the last element, then @next is NULL.
2270 */
2271 rcu_read_lock();
2272 next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path);
2273 rcu_read_unlock();
2274
2275 /*
2276 * @pcpu paths can still point to the path which is going to be
2277 * removed, so change the pointer manually.
2278 */
2279 for_each_possible_cpu(cpu) {
2280 struct rtrs_clt_path __rcu **ppcpu_path;
2281
2282 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu);
2283 if (rcu_dereference_protected(*ppcpu_path,
2284 lockdep_is_held(&clt->paths_mutex)) != clt_path)
2285 /*
2286 * synchronize_rcu() was called just after deleting
2287 * entry from the list, thus IO code path cannot
2288 * change pointer back to the pointer which is going
2289 * to be removed, we are safe here.
2290 */
2291 continue;
2292
2293 /*
2294 * We race with IO code path, which also changes pointer,
2295 * thus we have to be careful not to overwrite it.
2296 */
2297 if (try_cmpxchg((struct rtrs_clt_path **)ppcpu_path, &clt_path,
2298 next))
2299 /*
2300 * @ppcpu_path was successfully replaced with @next,
2301 * that means that someone could also pick up the
2302 * @sess and dereferencing it right now, so wait for
2303 * a grace period is required.
2304 */
2305 wait_for_grace = true;
2306 }
2307 if (wait_for_grace)
2308 synchronize_rcu();
2309
2310 mutex_unlock(&clt->paths_mutex);
2311 }
2312
rtrs_clt_add_path_to_arr(struct rtrs_clt_path * clt_path)2313 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path)
2314 {
2315 struct rtrs_clt_sess *clt = clt_path->clt;
2316
2317 mutex_lock(&clt->paths_mutex);
2318 clt->paths_num++;
2319
2320 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
2321 mutex_unlock(&clt->paths_mutex);
2322 }
2323
rtrs_clt_close_work(struct work_struct * work)2324 static void rtrs_clt_close_work(struct work_struct *work)
2325 {
2326 struct rtrs_clt_path *clt_path;
2327
2328 clt_path = container_of(work, struct rtrs_clt_path, close_work);
2329
2330 cancel_work_sync(&clt_path->err_recovery_work);
2331 cancel_delayed_work_sync(&clt_path->reconnect_dwork);
2332 rtrs_clt_stop_and_destroy_conns(clt_path);
2333 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL);
2334 }
2335
init_conns(struct rtrs_clt_path * clt_path)2336 static int init_conns(struct rtrs_clt_path *clt_path)
2337 {
2338 unsigned int cid;
2339 int err;
2340
2341 /*
2342 * On every new session connections increase reconnect counter
2343 * to avoid clashes with previous sessions not yet closed
2344 * sessions on a server side.
2345 */
2346 clt_path->s.recon_cnt++;
2347
2348 /* Establish all RDMA connections */
2349 for (cid = 0; cid < clt_path->s.con_num; cid++) {
2350 err = create_con(clt_path, cid);
2351 if (err)
2352 goto destroy;
2353
2354 err = create_cm(to_clt_con(clt_path->s.con[cid]));
2355 if (err) {
2356 destroy_con(to_clt_con(clt_path->s.con[cid]));
2357 goto destroy;
2358 }
2359 }
2360 err = alloc_path_reqs(clt_path);
2361 if (err)
2362 goto destroy;
2363
2364 rtrs_start_hb(&clt_path->s);
2365
2366 return 0;
2367
2368 destroy:
2369 while (cid--) {
2370 struct rtrs_clt_con *con = to_clt_con(clt_path->s.con[cid]);
2371
2372 stop_cm(con);
2373
2374 mutex_lock(&con->con_mutex);
2375 destroy_con_cq_qp(con);
2376 mutex_unlock(&con->con_mutex);
2377 destroy_cm(con);
2378 destroy_con(con);
2379 }
2380 /*
2381 * If we've never taken async path and got an error, say,
2382 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state
2383 * manually to keep reconnecting.
2384 */
2385 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
2386
2387 return err;
2388 }
2389
rtrs_clt_info_req_done(struct ib_cq * cq,struct ib_wc * wc)2390 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc)
2391 {
2392 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
2393 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
2394 struct rtrs_iu *iu;
2395
2396 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
2397 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
2398
2399 if (wc->status != IB_WC_SUCCESS) {
2400 rtrs_err(clt_path->clt, "Path info request send failed: %s\n",
2401 ib_wc_status_msg(wc->status));
2402 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL);
2403 return;
2404 }
2405
2406 rtrs_clt_update_wc_stats(con);
2407 }
2408
process_info_rsp(struct rtrs_clt_path * clt_path,const struct rtrs_msg_info_rsp * msg)2409 static int process_info_rsp(struct rtrs_clt_path *clt_path,
2410 const struct rtrs_msg_info_rsp *msg)
2411 {
2412 unsigned int sg_cnt, total_len;
2413 int i, sgi;
2414
2415 sg_cnt = le16_to_cpu(msg->sg_cnt);
2416 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) {
2417 rtrs_err(clt_path->clt,
2418 "Incorrect sg_cnt %d, is not multiple\n",
2419 sg_cnt);
2420 return -EINVAL;
2421 }
2422
2423 /*
2424 * Check if IB immediate data size is enough to hold the mem_id and
2425 * the offset inside the memory chunk.
2426 */
2427 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) >
2428 MAX_IMM_PAYL_BITS) {
2429 rtrs_err(clt_path->clt,
2430 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n",
2431 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size);
2432 return -EINVAL;
2433 }
2434 total_len = 0;
2435 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) {
2436 const struct rtrs_sg_desc *desc = &msg->desc[sgi];
2437 u32 len, rkey;
2438 u64 addr;
2439
2440 addr = le64_to_cpu(desc->addr);
2441 rkey = le32_to_cpu(desc->key);
2442 len = le32_to_cpu(desc->len);
2443
2444 total_len += len;
2445
2446 if (!len || (len % clt_path->chunk_size)) {
2447 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n",
2448 sgi,
2449 len);
2450 return -EINVAL;
2451 }
2452 for ( ; len && i < clt_path->queue_depth; i++) {
2453 clt_path->rbufs[i].addr = addr;
2454 clt_path->rbufs[i].rkey = rkey;
2455
2456 len -= clt_path->chunk_size;
2457 addr += clt_path->chunk_size;
2458 }
2459 }
2460 /* Sanity check */
2461 if (sgi != sg_cnt || i != clt_path->queue_depth) {
2462 rtrs_err(clt_path->clt,
2463 "Incorrect sg vector, not fully mapped\n");
2464 return -EINVAL;
2465 }
2466 if (total_len != clt_path->chunk_size * clt_path->queue_depth) {
2467 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len);
2468 return -EINVAL;
2469 }
2470
2471 return 0;
2472 }
2473
rtrs_clt_info_rsp_done(struct ib_cq * cq,struct ib_wc * wc)2474 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc)
2475 {
2476 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context);
2477 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path);
2478 struct rtrs_msg_info_rsp *msg;
2479 enum rtrs_clt_state state;
2480 struct rtrs_iu *iu;
2481 size_t rx_sz;
2482 int err;
2483
2484 state = RTRS_CLT_CONNECTING_ERR;
2485
2486 WARN_ON(con->c.cid);
2487 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
2488 if (wc->status != IB_WC_SUCCESS) {
2489 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n",
2490 ib_wc_status_msg(wc->status));
2491 goto out;
2492 }
2493 WARN_ON(wc->opcode != IB_WC_RECV);
2494
2495 if (wc->byte_len < sizeof(*msg)) {
2496 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
2497 wc->byte_len);
2498 goto out;
2499 }
2500 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr,
2501 iu->size, DMA_FROM_DEVICE);
2502 msg = iu->buf;
2503 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) {
2504 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n",
2505 le16_to_cpu(msg->type));
2506 goto out;
2507 }
2508 rx_sz = sizeof(*msg);
2509 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt);
2510 if (wc->byte_len < rx_sz) {
2511 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n",
2512 wc->byte_len);
2513 goto out;
2514 }
2515 err = process_info_rsp(clt_path, msg);
2516 if (err)
2517 goto out;
2518
2519 err = post_recv_path(clt_path);
2520 if (err)
2521 goto out;
2522
2523 state = RTRS_CLT_CONNECTED;
2524
2525 out:
2526 rtrs_clt_update_wc_stats(con);
2527 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1);
2528 rtrs_clt_change_state_get_old(clt_path, state, NULL);
2529 }
2530
rtrs_send_path_info(struct rtrs_clt_path * clt_path)2531 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path)
2532 {
2533 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]);
2534 struct rtrs_msg_info_req *msg;
2535 struct rtrs_iu *tx_iu, *rx_iu;
2536 size_t rx_sz;
2537 int err;
2538
2539 rx_sz = sizeof(struct rtrs_msg_info_rsp);
2540 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth;
2541
2542 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL,
2543 clt_path->s.dev->ib_dev, DMA_TO_DEVICE,
2544 rtrs_clt_info_req_done);
2545 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev,
2546 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done);
2547 if (!tx_iu || !rx_iu) {
2548 err = -ENOMEM;
2549 goto out;
2550 }
2551 /* Prepare for getting info response */
2552 err = rtrs_iu_post_recv(&usr_con->c, rx_iu);
2553 if (err) {
2554 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err);
2555 goto out;
2556 }
2557 rx_iu = NULL;
2558
2559 msg = tx_iu->buf;
2560 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ);
2561 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname));
2562
2563 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev,
2564 tx_iu->dma_addr,
2565 tx_iu->size, DMA_TO_DEVICE);
2566
2567 /* Send info request */
2568 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL);
2569 if (err) {
2570 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err);
2571 goto out;
2572 }
2573 tx_iu = NULL;
2574
2575 /* Wait for state change */
2576 wait_event_interruptible_timeout(clt_path->state_wq,
2577 clt_path->state != RTRS_CLT_CONNECTING,
2578 msecs_to_jiffies(
2579 RTRS_CONNECT_TIMEOUT_MS));
2580 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) {
2581 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR)
2582 err = -ECONNRESET;
2583 else
2584 err = -ETIMEDOUT;
2585 }
2586
2587 out:
2588 if (tx_iu)
2589 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1);
2590 if (rx_iu)
2591 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1);
2592 if (err)
2593 /* If we've never taken async path because of malloc problems */
2594 rtrs_clt_change_state_get_old(clt_path,
2595 RTRS_CLT_CONNECTING_ERR, NULL);
2596
2597 return err;
2598 }
2599
2600 /**
2601 * init_path() - establishes all path connections and does handshake
2602 * @clt_path: client path.
2603 * In case of error full close or reconnect procedure should be taken,
2604 * because reconnect or close async works can be started.
2605 */
init_path(struct rtrs_clt_path * clt_path)2606 static int init_path(struct rtrs_clt_path *clt_path)
2607 {
2608 int err;
2609 char str[NAME_MAX];
2610 struct rtrs_addr path = {
2611 .src = &clt_path->s.src_addr,
2612 .dst = &clt_path->s.dst_addr,
2613 };
2614
2615 rtrs_addr_to_str(&path, str, sizeof(str));
2616
2617 mutex_lock(&clt_path->init_mutex);
2618 err = init_conns(clt_path);
2619 if (err) {
2620 rtrs_err(clt_path->clt,
2621 "init_conns() failed: err=%d path=%s [%s:%u]\n", err,
2622 str, clt_path->hca_name, clt_path->hca_port);
2623 goto out;
2624 }
2625 err = rtrs_send_path_info(clt_path);
2626 if (err) {
2627 rtrs_err(clt_path->clt,
2628 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n",
2629 err, str, clt_path->hca_name, clt_path->hca_port);
2630 goto out;
2631 }
2632 rtrs_clt_path_up(clt_path);
2633 out:
2634 mutex_unlock(&clt_path->init_mutex);
2635
2636 return err;
2637 }
2638
rtrs_clt_reconnect_work(struct work_struct * work)2639 static void rtrs_clt_reconnect_work(struct work_struct *work)
2640 {
2641 struct rtrs_clt_path *clt_path;
2642 struct rtrs_clt_sess *clt;
2643 int err;
2644
2645 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path,
2646 reconnect_dwork);
2647 clt = clt_path->clt;
2648
2649 trace_rtrs_clt_reconnect_work(clt_path);
2650
2651 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING)
2652 return;
2653
2654 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) {
2655 /* Close a path completely if max attempts is reached */
2656 rtrs_clt_close_conns(clt_path, false);
2657 return;
2658 }
2659 clt_path->reconnect_attempts++;
2660
2661 msleep(RTRS_RECONNECT_BACKOFF);
2662 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) {
2663 err = init_path(clt_path);
2664 if (err)
2665 goto reconnect_again;
2666 }
2667
2668 return;
2669
2670 reconnect_again:
2671 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) {
2672 clt_path->stats->reconnects.fail_cnt++;
2673 queue_work(rtrs_wq, &clt_path->err_recovery_work);
2674 }
2675 }
2676
rtrs_clt_dev_release(struct device * dev)2677 static void rtrs_clt_dev_release(struct device *dev)
2678 {
2679 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess,
2680 dev);
2681
2682 mutex_destroy(&clt->paths_ev_mutex);
2683 mutex_destroy(&clt->paths_mutex);
2684 kfree(clt);
2685 }
2686
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)2687 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num,
2688 u16 port, size_t pdu_sz, void *priv,
2689 void (*link_ev)(void *priv,
2690 enum rtrs_clt_link_ev ev),
2691 unsigned int reconnect_delay_sec,
2692 unsigned int max_reconnect_attempts)
2693 {
2694 struct rtrs_clt_sess *clt;
2695 int err;
2696
2697 if (!paths_num || paths_num > MAX_PATHS_NUM)
2698 return ERR_PTR(-EINVAL);
2699
2700 if (strlen(sessname) >= sizeof(clt->sessname))
2701 return ERR_PTR(-EINVAL);
2702
2703 clt = kzalloc(sizeof(*clt), GFP_KERNEL);
2704 if (!clt)
2705 return ERR_PTR(-ENOMEM);
2706
2707 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path));
2708 if (!clt->pcpu_path) {
2709 kfree(clt);
2710 return ERR_PTR(-ENOMEM);
2711 }
2712
2713 clt->dev.class = rtrs_clt_dev_class;
2714 clt->dev.release = rtrs_clt_dev_release;
2715 uuid_gen(&clt->paths_uuid);
2716 INIT_LIST_HEAD_RCU(&clt->paths_list);
2717 clt->paths_num = paths_num;
2718 clt->paths_up = MAX_PATHS_NUM;
2719 clt->port = port;
2720 clt->pdu_sz = pdu_sz;
2721 clt->max_segments = RTRS_MAX_SEGMENTS;
2722 clt->reconnect_delay_sec = reconnect_delay_sec;
2723 clt->max_reconnect_attempts = max_reconnect_attempts;
2724 clt->priv = priv;
2725 clt->link_ev = link_ev;
2726 clt->mp_policy = MP_POLICY_MIN_INFLIGHT;
2727 strscpy(clt->sessname, sessname, sizeof(clt->sessname));
2728 init_waitqueue_head(&clt->permits_wait);
2729 mutex_init(&clt->paths_ev_mutex);
2730 mutex_init(&clt->paths_mutex);
2731 device_initialize(&clt->dev);
2732
2733 err = dev_set_name(&clt->dev, "%s", sessname);
2734 if (err)
2735 goto err_put;
2736
2737 /*
2738 * Suppress user space notification until
2739 * sysfs files are created
2740 */
2741 dev_set_uevent_suppress(&clt->dev, true);
2742 err = device_add(&clt->dev);
2743 if (err)
2744 goto err_put;
2745
2746 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj);
2747 if (!clt->kobj_paths) {
2748 err = -ENOMEM;
2749 goto err_del;
2750 }
2751 err = rtrs_clt_create_sysfs_root_files(clt);
2752 if (err) {
2753 kobject_del(clt->kobj_paths);
2754 kobject_put(clt->kobj_paths);
2755 goto err_del;
2756 }
2757 dev_set_uevent_suppress(&clt->dev, false);
2758 kobject_uevent(&clt->dev.kobj, KOBJ_ADD);
2759
2760 return clt;
2761 err_del:
2762 device_del(&clt->dev);
2763 err_put:
2764 free_percpu(clt->pcpu_path);
2765 put_device(&clt->dev);
2766 return ERR_PTR(err);
2767 }
2768
free_clt(struct rtrs_clt_sess * clt)2769 static void free_clt(struct rtrs_clt_sess *clt)
2770 {
2771 free_percpu(clt->pcpu_path);
2772
2773 /*
2774 * release callback will free clt and destroy mutexes in last put
2775 */
2776 device_unregister(&clt->dev);
2777 }
2778
2779 /**
2780 * rtrs_clt_open() - Open a path to an RTRS server
2781 * @ops: holds the link event callback and the private pointer.
2782 * @pathname: name of the path to an RTRS server
2783 * @paths: Paths to be established defined by their src and dst addresses
2784 * @paths_num: Number of elements in the @paths array
2785 * @port: port to be used by the RTRS session
2786 * @pdu_sz: Size of extra payload which can be accessed after permit allocation.
2787 * @reconnect_delay_sec: time between reconnect tries
2788 * @max_reconnect_attempts: Number of times to reconnect on error before giving
2789 * up, 0 for * disabled, -1 for forever
2790 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag
2791 *
2792 * Starts session establishment with the rtrs_server. The function can block
2793 * up to ~2000ms before it returns.
2794 *
2795 * Return a valid pointer on success otherwise PTR_ERR.
2796 */
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)2797 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops,
2798 const char *pathname,
2799 const struct rtrs_addr *paths,
2800 size_t paths_num, u16 port,
2801 size_t pdu_sz, u8 reconnect_delay_sec,
2802 s16 max_reconnect_attempts, u32 nr_poll_queues)
2803 {
2804 struct rtrs_clt_path *clt_path, *tmp;
2805 struct rtrs_clt_sess *clt;
2806 int err, i;
2807
2808 if (strchr(pathname, '/') || strchr(pathname, '.')) {
2809 pr_err("pathname cannot contain / and .\n");
2810 err = -EINVAL;
2811 goto out;
2812 }
2813
2814 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv,
2815 ops->link_ev,
2816 reconnect_delay_sec,
2817 max_reconnect_attempts);
2818 if (IS_ERR(clt)) {
2819 err = PTR_ERR(clt);
2820 goto out;
2821 }
2822 for (i = 0; i < paths_num; i++) {
2823 struct rtrs_clt_path *clt_path;
2824
2825 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids,
2826 nr_poll_queues);
2827 if (IS_ERR(clt_path)) {
2828 err = PTR_ERR(clt_path);
2829 goto close_all_path;
2830 }
2831 if (!i)
2832 clt_path->for_new_clt = 1;
2833 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list);
2834
2835 err = init_path(clt_path);
2836 if (err) {
2837 list_del_rcu(&clt_path->s.entry);
2838 rtrs_clt_close_conns(clt_path, true);
2839 free_percpu(clt_path->stats->pcpu_stats);
2840 kfree(clt_path->stats);
2841 free_path(clt_path);
2842 goto close_all_path;
2843 }
2844
2845 err = rtrs_clt_create_path_files(clt_path);
2846 if (err) {
2847 list_del_rcu(&clt_path->s.entry);
2848 rtrs_clt_close_conns(clt_path, true);
2849 free_percpu(clt_path->stats->pcpu_stats);
2850 kfree(clt_path->stats);
2851 free_path(clt_path);
2852 goto close_all_path;
2853 }
2854 }
2855 err = alloc_permits(clt);
2856 if (err)
2857 goto close_all_path;
2858
2859 return clt;
2860
2861 close_all_path:
2862 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
2863 rtrs_clt_destroy_path_files(clt_path, NULL);
2864 rtrs_clt_close_conns(clt_path, true);
2865 kobject_put(&clt_path->kobj);
2866 }
2867 rtrs_clt_destroy_sysfs_root(clt);
2868 free_clt(clt);
2869
2870 out:
2871 return ERR_PTR(err);
2872 }
2873 EXPORT_SYMBOL(rtrs_clt_open);
2874
2875 /**
2876 * rtrs_clt_close() - Close a path
2877 * @clt: Session handle. Session is freed upon return.
2878 */
rtrs_clt_close(struct rtrs_clt_sess * clt)2879 void rtrs_clt_close(struct rtrs_clt_sess *clt)
2880 {
2881 struct rtrs_clt_path *clt_path, *tmp;
2882
2883 /* Firstly forbid sysfs access */
2884 rtrs_clt_destroy_sysfs_root(clt);
2885
2886 /* Now it is safe to iterate over all paths without locks */
2887 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) {
2888 rtrs_clt_close_conns(clt_path, true);
2889 rtrs_clt_destroy_path_files(clt_path, NULL);
2890 kobject_put(&clt_path->kobj);
2891 }
2892 free_permits(clt);
2893 free_clt(clt);
2894 }
2895 EXPORT_SYMBOL(rtrs_clt_close);
2896
rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path * clt_path)2897 int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path)
2898 {
2899 enum rtrs_clt_state old_state;
2900 int err = -EBUSY;
2901 bool changed;
2902
2903 changed = rtrs_clt_change_state_get_old(clt_path,
2904 RTRS_CLT_RECONNECTING,
2905 &old_state);
2906 if (changed) {
2907 clt_path->reconnect_attempts = 0;
2908 rtrs_clt_stop_and_destroy_conns(clt_path);
2909 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0);
2910 }
2911 if (changed || old_state == RTRS_CLT_RECONNECTING) {
2912 /*
2913 * flush_delayed_work() queues pending work for immediate
2914 * execution, so do the flush if we have queued something
2915 * right now or work is pending.
2916 */
2917 flush_delayed_work(&clt_path->reconnect_dwork);
2918 err = (READ_ONCE(clt_path->state) ==
2919 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN);
2920 }
2921
2922 return err;
2923 }
2924
rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path * clt_path,const struct attribute * sysfs_self)2925 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path,
2926 const struct attribute *sysfs_self)
2927 {
2928 enum rtrs_clt_state old_state;
2929 bool changed;
2930
2931 /*
2932 * Continue stopping path till state was changed to DEAD or
2933 * state was observed as DEAD:
2934 * 1. State was changed to DEAD - we were fast and nobody
2935 * invoked rtrs_clt_reconnect(), which can again start
2936 * reconnecting.
2937 * 2. State was observed as DEAD - we have someone in parallel
2938 * removing the path.
2939 */
2940 do {
2941 rtrs_clt_close_conns(clt_path, true);
2942 changed = rtrs_clt_change_state_get_old(clt_path,
2943 RTRS_CLT_DEAD,
2944 &old_state);
2945 } while (!changed && old_state != RTRS_CLT_DEAD);
2946
2947 if (changed) {
2948 rtrs_clt_remove_path_from_arr(clt_path);
2949 rtrs_clt_destroy_path_files(clt_path, sysfs_self);
2950 kobject_put(&clt_path->kobj);
2951 }
2952
2953 return 0;
2954 }
2955
rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess * clt,int value)2956 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value)
2957 {
2958 clt->max_reconnect_attempts = (unsigned int)value;
2959 }
2960
rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess * clt)2961 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt)
2962 {
2963 return (int)clt->max_reconnect_attempts;
2964 }
2965
2966 /**
2967 * rtrs_clt_request() - Request data transfer to/from server via RDMA.
2968 *
2969 * @dir: READ/WRITE
2970 * @ops: callback function to be called as confirmation, and the pointer.
2971 * @clt: Session
2972 * @permit: Preallocated permit
2973 * @vec: Message that is sent to server together with the request.
2974 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE.
2975 * Since the msg is copied internally it can be allocated on stack.
2976 * @nr: Number of elements in @vec.
2977 * @data_len: length of data sent to/from server
2978 * @sg: Pages to be sent/received to/from server.
2979 * @sg_cnt: Number of elements in the @sg
2980 *
2981 * Return:
2982 * 0: Success
2983 * <0: Error
2984 *
2985 * On dir=READ rtrs client will request a data transfer from Server to client.
2986 * The data that the server will respond with will be stored in @sg when
2987 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event.
2988 * On dir=WRITE rtrs client will rdma write data in sg to server side.
2989 */
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)2990 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
2991 struct rtrs_clt_sess *clt, struct rtrs_permit *permit,
2992 const struct kvec *vec, size_t nr, size_t data_len,
2993 struct scatterlist *sg, unsigned int sg_cnt)
2994 {
2995 struct rtrs_clt_io_req *req;
2996 struct rtrs_clt_path *clt_path;
2997
2998 enum dma_data_direction dma_dir;
2999 int err = -ECONNABORTED, i;
3000 size_t usr_len, hdr_len;
3001 struct path_it it;
3002
3003 /* Get kvec length */
3004 for (i = 0, usr_len = 0; i < nr; i++)
3005 usr_len += vec[i].iov_len;
3006
3007 if (dir == READ) {
3008 hdr_len = sizeof(struct rtrs_msg_rdma_read) +
3009 sg_cnt * sizeof(struct rtrs_sg_desc);
3010 dma_dir = DMA_FROM_DEVICE;
3011 } else {
3012 hdr_len = sizeof(struct rtrs_msg_rdma_write);
3013 dma_dir = DMA_TO_DEVICE;
3014 }
3015
3016 rcu_read_lock();
3017 for (path_it_init(&it, clt);
3018 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
3019 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
3020 continue;
3021
3022 if (usr_len + hdr_len > clt_path->max_hdr_size) {
3023 rtrs_wrn_rl(clt_path->clt,
3024 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n",
3025 dir == READ ? "Read" : "Write",
3026 usr_len, hdr_len, clt_path->max_hdr_size);
3027 err = -EMSGSIZE;
3028 break;
3029 }
3030 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv,
3031 vec, usr_len, sg, sg_cnt, data_len,
3032 dma_dir);
3033 if (dir == READ)
3034 err = rtrs_clt_read_req(req);
3035 else
3036 err = rtrs_clt_write_req(req);
3037 if (err) {
3038 req->in_use = false;
3039 continue;
3040 }
3041 /* Success path */
3042 break;
3043 }
3044 path_it_deinit(&it);
3045 rcu_read_unlock();
3046
3047 return err;
3048 }
3049 EXPORT_SYMBOL(rtrs_clt_request);
3050
rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess * clt,unsigned int index)3051 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index)
3052 {
3053 /* If no path, return -1 for block layer not to try again */
3054 int cnt = -1;
3055 struct rtrs_con *con;
3056 struct rtrs_clt_path *clt_path;
3057 struct path_it it;
3058
3059 rcu_read_lock();
3060 for (path_it_init(&it, clt);
3061 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
3062 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED)
3063 continue;
3064
3065 con = clt_path->s.con[index + 1];
3066 cnt = ib_process_cq_direct(con->cq, -1);
3067 if (cnt)
3068 break;
3069 }
3070 path_it_deinit(&it);
3071 rcu_read_unlock();
3072
3073 return cnt;
3074 }
3075 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct);
3076
3077 /**
3078 * rtrs_clt_query() - queries RTRS session attributes
3079 *@clt: session pointer
3080 *@attr: query results for session attributes.
3081 * Returns:
3082 * 0 on success
3083 * -ECOMM no connection to the server
3084 */
rtrs_clt_query(struct rtrs_clt_sess * clt,struct rtrs_attrs * attr)3085 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr)
3086 {
3087 if (!rtrs_clt_is_connected(clt))
3088 return -ECOMM;
3089
3090 attr->queue_depth = clt->queue_depth;
3091 attr->max_segments = clt->max_segments;
3092 /* Cap max_io_size to min of remote buffer size and the fr pages */
3093 attr->max_io_size = min_t(int, clt->max_io_size,
3094 clt->max_segments * SZ_4K);
3095
3096 return 0;
3097 }
3098 EXPORT_SYMBOL(rtrs_clt_query);
3099
rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess * clt,struct rtrs_addr * addr)3100 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt,
3101 struct rtrs_addr *addr)
3102 {
3103 struct rtrs_clt_path *clt_path;
3104 int err;
3105
3106 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0);
3107 if (IS_ERR(clt_path))
3108 return PTR_ERR(clt_path);
3109
3110 mutex_lock(&clt->paths_mutex);
3111 if (clt->paths_num == 0) {
3112 /*
3113 * When all the paths are removed for a session,
3114 * the addition of the first path is like a new session for
3115 * the storage server
3116 */
3117 clt_path->for_new_clt = 1;
3118 }
3119
3120 mutex_unlock(&clt->paths_mutex);
3121
3122 /*
3123 * It is totally safe to add path in CONNECTING state: coming
3124 * IO will never grab it. Also it is very important to add
3125 * path before init, since init fires LINK_CONNECTED event.
3126 */
3127 rtrs_clt_add_path_to_arr(clt_path);
3128
3129 err = init_path(clt_path);
3130 if (err)
3131 goto close_path;
3132
3133 err = rtrs_clt_create_path_files(clt_path);
3134 if (err)
3135 goto close_path;
3136
3137 return 0;
3138
3139 close_path:
3140 rtrs_clt_remove_path_from_arr(clt_path);
3141 rtrs_clt_close_conns(clt_path, true);
3142 free_percpu(clt_path->stats->pcpu_stats);
3143 kfree(clt_path->stats);
3144 free_path(clt_path);
3145
3146 return err;
3147 }
3148
rtrs_clt_ib_dev_init(struct rtrs_ib_dev * dev)3149 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev)
3150 {
3151 if (!(dev->ib_dev->attrs.device_cap_flags &
3152 IB_DEVICE_MEM_MGT_EXTENSIONS)) {
3153 pr_err("Memory registrations not supported.\n");
3154 return -ENOTSUPP;
3155 }
3156
3157 return 0;
3158 }
3159
3160 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = {
3161 .init = rtrs_clt_ib_dev_init
3162 };
3163
rtrs_client_init(void)3164 static int __init rtrs_client_init(void)
3165 {
3166 rtrs_rdma_dev_pd_init(0, &dev_pd);
3167
3168 rtrs_clt_dev_class = class_create(THIS_MODULE, "rtrs-client");
3169 if (IS_ERR(rtrs_clt_dev_class)) {
3170 pr_err("Failed to create rtrs-client dev class\n");
3171 return PTR_ERR(rtrs_clt_dev_class);
3172 }
3173 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0);
3174 if (!rtrs_wq) {
3175 class_destroy(rtrs_clt_dev_class);
3176 return -ENOMEM;
3177 }
3178
3179 return 0;
3180 }
3181
rtrs_client_exit(void)3182 static void __exit rtrs_client_exit(void)
3183 {
3184 destroy_workqueue(rtrs_wq);
3185 class_destroy(rtrs_clt_dev_class);
3186 rtrs_rdma_dev_pd_deinit(&dev_pd);
3187 }
3188
3189 module_init(rtrs_client_init);
3190 module_exit(rtrs_client_exit);
3191
