-
Notifications
You must be signed in to change notification settings - Fork 102
/
rtrs-clt.c
3000 lines (2605 loc) · 76.6 KB
/
rtrs-clt.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RDMA Transport Layer
*
* Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
* Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
* Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
*/
#undef pr_fmt
#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
#include <linux/module.h>
#include <linux/rculist.h>
#include <linux/random.h>
#include "rtrs-clt.h"
#include "rtrs-log.h"
#define RTRS_CONNECT_TIMEOUT_MS 30000
/*
* Wait a bit before trying to reconnect after a failure
* in order to give server time to finish clean up which
* leads to "false positives" failed reconnect attempts
*/
#define RTRS_RECONNECT_BACKOFF 1000
/*
* Wait for additional random time between 0 and 8 seconds
* before starting to reconnect to avoid clients reconnecting
* all at once in case of a major network outage
*/
#define RTRS_RECONNECT_SEED 8
MODULE_DESCRIPTION("RDMA Transport Client");
MODULE_LICENSE("GPL");
static const struct rtrs_rdma_dev_pd_ops dev_pd_ops;
static struct rtrs_rdma_dev_pd dev_pd = {
.ops = &dev_pd_ops
};
static struct workqueue_struct *rtrs_wq;
static struct class *rtrs_clt_dev_class;
static inline bool rtrs_clt_is_connected(const struct rtrs_clt *clt)
{
struct rtrs_clt_sess *sess;
bool connected = false;
rcu_read_lock();
list_for_each_entry_rcu(sess, &clt->paths_list, s.entry)
connected |= READ_ONCE(sess->state) == RTRS_CLT_CONNECTED;
rcu_read_unlock();
return connected;
}
static struct rtrs_permit *
__rtrs_get_permit(struct rtrs_clt *clt, enum rtrs_clt_con_type con_type)
{
size_t max_depth = clt->queue_depth;
struct rtrs_permit *permit;
int bit;
/*
* Adapted from null_blk get_tag(). Callers from different cpus may
* grab the same bit, since find_first_zero_bit is not atomic.
* But then the test_and_set_bit_lock will fail for all the
* callers but one, so that they will loop again.
* This way an explicit spinlock is not required.
*/
do {
bit = find_first_zero_bit(clt->permits_map, max_depth);
if (unlikely(bit >= max_depth))
return NULL;
} while (unlikely(test_and_set_bit_lock(bit, clt->permits_map)));
permit = get_permit(clt, bit);
WARN_ON(permit->mem_id != bit);
permit->cpu_id = raw_smp_processor_id();
permit->con_type = con_type;
return permit;
}
static inline void __rtrs_put_permit(struct rtrs_clt *clt,
struct rtrs_permit *permit)
{
clear_bit_unlock(permit->mem_id, clt->permits_map);
}
/**
* rtrs_clt_get_permit() - allocates permit for future RDMA operation
* @clt: Current session
* @con_type: Type of connection to use with the permit
* @can_wait: Wait type
*
* Description:
* Allocates permit for the following RDMA operation. Permit is used
* to preallocate all resources and to propagate memory pressure
* up earlier.
*
* Context:
* Can sleep if @wait == RTRS_TAG_WAIT
*/
struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt *clt,
enum rtrs_clt_con_type con_type,
int can_wait)
{
struct rtrs_permit *permit;
DEFINE_WAIT(wait);
permit = __rtrs_get_permit(clt, con_type);
if (likely(permit) || !can_wait)
return permit;
do {
prepare_to_wait(&clt->permits_wait, &wait,
TASK_UNINTERRUPTIBLE);
permit = __rtrs_get_permit(clt, con_type);
if (likely(permit))
break;
io_schedule();
} while (1);
finish_wait(&clt->permits_wait, &wait);
return permit;
}
EXPORT_SYMBOL(rtrs_clt_get_permit);
/**
* rtrs_clt_put_permit() - puts allocated permit
* @clt: Current session
* @permit: Permit to be freed
*
* Context:
* Does not matter
*/
void rtrs_clt_put_permit(struct rtrs_clt *clt, struct rtrs_permit *permit)
{
if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map)))
return;
__rtrs_put_permit(clt, permit);
/*
* rtrs_clt_get_permit() adds itself to the &clt->permits_wait list
* before calling schedule(). So if rtrs_clt_get_permit() is sleeping
* it must have added itself to &clt->permits_wait before
* __rtrs_put_permit() finished.
* Hence it is safe to guard wake_up() with a waitqueue_active() test.
*/
if (waitqueue_active(&clt->permits_wait))
wake_up(&clt->permits_wait);
}
EXPORT_SYMBOL(rtrs_clt_put_permit);
void *rtrs_permit_to_pdu(struct rtrs_permit *permit)
{
return permit + 1;
}
EXPORT_SYMBOL(rtrs_permit_to_pdu);
/**
* rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit
* @sess: client session pointer
* @permit: permit for the allocation of the RDMA buffer
* Note:
* IO connection starts from 1.
* 0 connection is for user messages.
*/
static
struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_sess *sess,
struct rtrs_permit *permit)
{
int id = 0;
if (likely(permit->con_type == RTRS_IO_CON))
id = (permit->cpu_id % (sess->s.con_num - 1)) + 1;
return to_clt_con(sess->s.con[id]);
}
/**
* __rtrs_clt_change_state() - change the session state through session state
* machine.
*
* @sess: client session to change the state of.
* @new_state: state to change to.
*
* returns true if successful, false if the requested state can not be set.
*
* Locks:
* state_wq lock must be hold.
*/
static bool __rtrs_clt_change_state(struct rtrs_clt_sess *sess,
enum rtrs_clt_state new_state)
{
enum rtrs_clt_state old_state;
bool changed = false;
lockdep_assert_held(&sess->state_wq.lock);
old_state = sess->state;
switch (new_state) {
case RTRS_CLT_CONNECTING:
switch (old_state) {
case RTRS_CLT_RECONNECTING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_RECONNECTING:
switch (old_state) {
case RTRS_CLT_CONNECTED:
case RTRS_CLT_CONNECTING_ERR:
case RTRS_CLT_CLOSED:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CONNECTED:
switch (old_state) {
case RTRS_CLT_CONNECTING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CONNECTING_ERR:
switch (old_state) {
case RTRS_CLT_CONNECTING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CLOSING:
switch (old_state) {
case RTRS_CLT_CONNECTING:
case RTRS_CLT_CONNECTING_ERR:
case RTRS_CLT_RECONNECTING:
case RTRS_CLT_CONNECTED:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_CLOSED:
switch (old_state) {
case RTRS_CLT_CLOSING:
changed = true;
fallthrough;
default:
break;
}
break;
case RTRS_CLT_DEAD:
switch (old_state) {
case RTRS_CLT_CLOSED:
changed = true;
fallthrough;
default:
break;
}
break;
default:
break;
}
if (changed) {
sess->state = new_state;
wake_up_locked(&sess->state_wq);
}
return changed;
}
static bool rtrs_clt_change_state_from_to(struct rtrs_clt_sess *sess,
enum rtrs_clt_state old_state,
enum rtrs_clt_state new_state)
{
bool changed = false;
spin_lock_irq(&sess->state_wq.lock);
if (sess->state == old_state)
changed = __rtrs_clt_change_state(sess, new_state);
spin_unlock_irq(&sess->state_wq.lock);
return changed;
}
static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
if (rtrs_clt_change_state_from_to(sess,
RTRS_CLT_CONNECTED,
RTRS_CLT_RECONNECTING)) {
struct rtrs_clt *clt = sess->clt;
unsigned int delay_ms;
/*
* Normal scenario, reconnect if we were successfully connected
*/
delay_ms = clt->reconnect_delay_sec * 1000;
queue_delayed_work(rtrs_wq, &sess->reconnect_dwork,
msecs_to_jiffies(delay_ms +
prandom_u32() % RTRS_RECONNECT_SEED));
} else {
/*
* Error can happen just on establishing new connection,
* so notify waiter with error state, waiter is responsible
* for cleaning the rest and reconnect if needed.
*/
rtrs_clt_change_state_from_to(sess,
RTRS_CLT_CONNECTING,
RTRS_CLT_CONNECTING_ERR);
}
}
static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_con *con = cq->cq_context;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
rtrs_err(con->c.sess, "Failed IB_WR_REG_MR: %s\n",
ib_wc_status_msg(wc->status));
rtrs_rdma_error_recovery(con);
}
}
static struct ib_cqe fast_reg_cqe = {
.done = rtrs_clt_fast_reg_done
};
static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
bool notify, bool can_wait);
static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_io_req *req =
container_of(wc->wr_cqe, typeof(*req), inv_cqe);
struct rtrs_clt_con *con = cq->cq_context;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
rtrs_err(con->c.sess, "Failed IB_WR_LOCAL_INV: %s\n",
ib_wc_status_msg(wc->status));
rtrs_rdma_error_recovery(con);
}
req->need_inv = false;
if (likely(req->need_inv_comp))
complete(&req->inv_comp);
else
/* Complete request from INV callback */
complete_rdma_req(req, req->inv_errno, true, false);
}
static int rtrs_inv_rkey(struct rtrs_clt_io_req *req)
{
struct rtrs_clt_con *con = req->con;
struct ib_send_wr wr = {
.opcode = IB_WR_LOCAL_INV,
.wr_cqe = &req->inv_cqe,
.send_flags = IB_SEND_SIGNALED,
.ex.invalidate_rkey = req->mr->rkey,
};
req->inv_cqe.done = rtrs_clt_inv_rkey_done;
return ib_post_send(con->c.qp, &wr, NULL);
}
static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno,
bool notify, bool can_wait)
{
struct rtrs_clt_con *con = req->con;
struct rtrs_clt_sess *sess;
int err;
if (WARN_ON(!req->in_use))
return;
if (WARN_ON(!req->con))
return;
sess = to_clt_sess(con->c.sess);
if (req->sg_cnt) {
if (unlikely(req->dir == DMA_FROM_DEVICE && req->need_inv)) {
/*
* We are here to invalidate read requests
* ourselves. In normal scenario server should
* send INV for all read requests, but
* we are here, thus two things could happen:
*
* 1. this is failover, when errno != 0
* and can_wait == 1,
*
* 2. something totally bad happened and
* server forgot to send INV, so we
* should do that ourselves.
*/
if (likely(can_wait)) {
req->need_inv_comp = true;
} else {
/* This should be IO path, so always notify */
WARN_ON(!notify);
/* Save errno for INV callback */
req->inv_errno = errno;
}
err = rtrs_inv_rkey(req);
if (unlikely(err)) {
rtrs_err(con->c.sess, "Send INV WR key=%#x: %d\n",
req->mr->rkey, err);
} else if (likely(can_wait)) {
wait_for_completion(&req->inv_comp);
} else {
/*
* Something went wrong, so request will be
* completed from INV callback.
*/
WARN_ON_ONCE(1);
return;
}
}
ib_dma_unmap_sg(sess->s.dev->ib_dev, req->sglist,
req->sg_cnt, req->dir);
}
if (sess->clt->mp_policy == MP_POLICY_MIN_INFLIGHT)
atomic_dec(&sess->stats->inflight);
req->in_use = false;
req->con = NULL;
if (notify)
req->conf(req->priv, errno);
}
static int 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)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
enum ib_send_flags flags;
struct ib_sge sge;
if (unlikely(!req->sg_size)) {
rtrs_wrn(con->c.sess,
"Doing RDMA Write failed, no data supplied\n");
return -EINVAL;
}
/* user data and user message in the first list element */
sge.addr = req->iu->dma_addr;
sge.length = req->sg_size;
sge.lkey = sess->s.dev->ib_pd->local_dma_lkey;
/*
* From time to time we have to post signalled sends,
* or send queue will fill up and only QP reset can help.
*/
flags = atomic_inc_return(&con->io_cnt) % sess->queue_depth ?
0 : IB_SEND_SIGNALED;
ib_dma_sync_single_for_device(sess->s.dev->ib_dev, req->iu->dma_addr,
req->sg_size, DMA_TO_DEVICE);
return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1,
rbuf->rkey, rbuf->addr + off,
imm, flags, wr);
}
static void process_io_rsp(struct rtrs_clt_sess *sess, u32 msg_id,
s16 errno, bool w_inval)
{
struct rtrs_clt_io_req *req;
if (WARN_ON(msg_id >= sess->queue_depth))
return;
req = &sess->reqs[msg_id];
/* Drop need_inv if server responded with send with invalidation */
req->need_inv &= !w_inval;
complete_rdma_req(req, errno, true, false);
}
static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc)
{
struct rtrs_iu *iu;
int err;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
WARN_ON(sess->flags != RTRS_MSG_NEW_RKEY_F);
iu = container_of(wc->wr_cqe, struct rtrs_iu,
cqe);
err = rtrs_iu_post_recv(&con->c, iu);
if (unlikely(err)) {
rtrs_err(con->c.sess, "post iu failed %d\n", err);
rtrs_rdma_error_recovery(con);
}
}
static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct rtrs_msg_rkey_rsp *msg;
u32 imm_type, imm_payload;
bool w_inval = false;
struct rtrs_iu *iu;
u32 buf_id;
int err;
WARN_ON(sess->flags != RTRS_MSG_NEW_RKEY_F);
iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe);
if (unlikely(wc->byte_len < sizeof(*msg))) {
rtrs_err(con->c.sess, "rkey response is malformed: size %d\n",
wc->byte_len);
goto out;
}
ib_dma_sync_single_for_cpu(sess->s.dev->ib_dev, iu->dma_addr,
iu->size, DMA_FROM_DEVICE);
msg = iu->buf;
if (unlikely(le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP)) {
rtrs_err(sess->clt, "rkey response is malformed: type %d\n",
le16_to_cpu(msg->type));
goto out;
}
buf_id = le16_to_cpu(msg->buf_id);
if (WARN_ON(buf_id >= sess->queue_depth))
goto out;
rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload);
if (likely(imm_type == RTRS_IO_RSP_IMM ||
imm_type == RTRS_IO_RSP_W_INV_IMM)) {
u32 msg_id;
w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
if (WARN_ON(buf_id != msg_id))
goto out;
sess->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey);
process_io_rsp(sess, msg_id, err, w_inval);
}
ib_dma_sync_single_for_device(sess->s.dev->ib_dev, iu->dma_addr,
iu->size, DMA_FROM_DEVICE);
return rtrs_clt_recv_done(con, wc);
out:
rtrs_rdma_error_recovery(con);
}
static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc);
static struct ib_cqe io_comp_cqe = {
.done = rtrs_clt_rdma_done
};
/*
* Post x2 empty WRs: first is for this RDMA with IMM,
* second is for RECV with INV, which happened earlier.
*/
static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe)
{
struct ib_recv_wr wr_arr[2], *wr;
int i;
memset(wr_arr, 0, sizeof(wr_arr));
for (i = 0; i < ARRAY_SIZE(wr_arr); i++) {
wr = &wr_arr[i];
wr->wr_cqe = cqe;
if (i)
/* Chain backwards */
wr->next = &wr_arr[i - 1];
}
return ib_post_recv(con->qp, wr, NULL);
}
static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct rtrs_clt_con *con = cq->cq_context;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
u32 imm_type, imm_payload;
bool w_inval = false;
int err;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
if (wc->status != IB_WC_WR_FLUSH_ERR) {
rtrs_err(sess->clt, "RDMA failed: %s\n",
ib_wc_status_msg(wc->status));
rtrs_rdma_error_recovery(con);
}
return;
}
rtrs_clt_update_wc_stats(con);
switch (wc->opcode) {
case IB_WC_RECV_RDMA_WITH_IMM:
/*
* post_recv() RDMA write completions of IO reqs (read/write)
* and hb
*/
if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done))
return;
rtrs_from_imm(be32_to_cpu(wc->ex.imm_data),
&imm_type, &imm_payload);
if (likely(imm_type == RTRS_IO_RSP_IMM ||
imm_type == RTRS_IO_RSP_W_INV_IMM)) {
u32 msg_id;
w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM);
rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err);
process_io_rsp(sess, msg_id, err, w_inval);
} else if (imm_type == RTRS_HB_MSG_IMM) {
WARN_ON(con->c.cid);
rtrs_send_hb_ack(&sess->s);
if (sess->flags == RTRS_MSG_NEW_RKEY_F)
return rtrs_clt_recv_done(con, wc);
} else if (imm_type == RTRS_HB_ACK_IMM) {
WARN_ON(con->c.cid);
sess->s.hb_missed_cnt = 0;
if (sess->flags == RTRS_MSG_NEW_RKEY_F)
return rtrs_clt_recv_done(con, wc);
} else {
rtrs_wrn(con->c.sess, "Unknown IMM type %u\n",
imm_type);
}
if (w_inval)
/*
* Post x2 empty WRs: first is for this RDMA with IMM,
* second is for RECV with INV, which happened earlier.
*/
err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe);
else
err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
if (unlikely(err)) {
rtrs_err(con->c.sess, "rtrs_post_recv_empty(): %d\n",
err);
rtrs_rdma_error_recovery(con);
break;
}
break;
case IB_WC_RECV:
/*
* Key invalidations from server side
*/
WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE ||
wc->wc_flags & IB_WC_WITH_IMM));
WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done);
if (sess->flags == RTRS_MSG_NEW_RKEY_F) {
if (wc->wc_flags & IB_WC_WITH_INVALIDATE)
return rtrs_clt_recv_done(con, wc);
return rtrs_clt_rkey_rsp_done(con, wc);
}
break;
case IB_WC_RDMA_WRITE:
/*
* post_send() RDMA write completions of IO reqs (read/write)
* and hb
*/
break;
default:
rtrs_wrn(sess->clt, "Unexpected WC type: %d\n", wc->opcode);
return;
}
}
static int post_recv_io(struct rtrs_clt_con *con, size_t q_size)
{
int err, i;
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
for (i = 0; i < q_size; i++) {
if (sess->flags == RTRS_MSG_NEW_RKEY_F) {
struct rtrs_iu *iu = &con->rsp_ius[i];
err = rtrs_iu_post_recv(&con->c, iu);
} else {
err = rtrs_post_recv_empty(&con->c, &io_comp_cqe);
}
if (unlikely(err))
return err;
}
return 0;
}
static int post_recv_sess(struct rtrs_clt_sess *sess)
{
size_t q_size = 0;
int err, cid;
for (cid = 0; cid < sess->s.con_num; cid++) {
if (cid == 0)
q_size = SERVICE_CON_QUEUE_DEPTH;
else
q_size = sess->queue_depth;
/*
* x2 for RDMA read responses + FR key invalidations,
* RDMA writes do not require any FR registrations.
*/
q_size *= 2;
err = post_recv_io(to_clt_con(sess->s.con[cid]), q_size);
if (unlikely(err)) {
rtrs_err(sess->clt, "post_recv_io(), err: %d\n", err);
return err;
}
}
return 0;
}
struct path_it {
int i;
struct list_head skip_list;
struct rtrs_clt *clt;
struct rtrs_clt_sess *(*next_path)(struct path_it *it);
};
/**
* list_next_or_null_rr_rcu - get next list element in round-robin fashion.
* @head: the head for the list.
* @ptr: the list head to take the next element from.
* @type: the type of the struct this is embedded in.
* @memb: the name of the list_head within the struct.
*
* Next element returned in round-robin fashion, i.e. head will be skipped,
* but if list is observed as empty, NULL will be returned.
*
* This primitive may safely run concurrently with the _rcu list-mutation
* primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
*/
#define list_next_or_null_rr_rcu(head, ptr, type, memb) \
({ \
list_next_or_null_rcu(head, ptr, type, memb) ?: \
list_next_or_null_rcu(head, READ_ONCE((ptr)->next), \
type, memb); \
})
/**
* get_next_path_rr() - Returns path in round-robin fashion.
* @it: the path pointer
*
* Related to @MP_POLICY_RR
*
* Locks:
* rcu_read_lock() must be hold.
*/
static struct rtrs_clt_sess *get_next_path_rr(struct path_it *it)
{
struct rtrs_clt_sess __rcu **ppcpu_path;
struct rtrs_clt_sess *path;
struct rtrs_clt *clt;
clt = it->clt;
/*
* Here we use two RCU objects: @paths_list and @pcpu_path
* pointer. See rtrs_clt_remove_path_from_arr() for details
* how that is handled.
*/
ppcpu_path = this_cpu_ptr(clt->pcpu_path);
path = rcu_dereference(*ppcpu_path);
if (unlikely(!path))
path = list_first_or_null_rcu(&clt->paths_list,
typeof(*path), s.entry);
else
path = list_next_or_null_rr_rcu(&clt->paths_list,
&path->s.entry,
typeof(*path),
s.entry);
rcu_assign_pointer(*ppcpu_path, path);
return path;
}
/**
* get_next_path_min_inflight() - Returns path with minimal inflight count.
* @it: the path pointer
*
* Related to @MP_POLICY_MIN_INFLIGHT
*
* Locks:
* rcu_read_lock() must be hold.
*/
static struct rtrs_clt_sess *get_next_path_min_inflight(struct path_it *it)
{
struct rtrs_clt_sess *min_path = NULL;
struct rtrs_clt *clt = it->clt;
struct rtrs_clt_sess *sess;
int min_inflight = INT_MAX;
int inflight;
list_for_each_entry_rcu(sess, &clt->paths_list, s.entry) {
if (unlikely(!list_empty(raw_cpu_ptr(sess->mp_skip_entry))))
continue;
inflight = atomic_read(&sess->stats->inflight);
if (inflight < min_inflight) {
min_inflight = inflight;
min_path = sess;
}
}
/*
* add the path to the skip list, so that next time we can get
* a different one
*/
if (min_path)
list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list);
return min_path;
}
static inline void path_it_init(struct path_it *it, struct rtrs_clt *clt)
{
INIT_LIST_HEAD(&it->skip_list);
it->clt = clt;
it->i = 0;
if (clt->mp_policy == MP_POLICY_RR)
it->next_path = get_next_path_rr;
else
it->next_path = get_next_path_min_inflight;
}
static inline void path_it_deinit(struct path_it *it)
{
struct list_head *skip, *tmp;
/*
* The skip_list is used only for the MIN_INFLIGHT policy.
* We need to remove paths from it, so that next IO can insert
* paths (->mp_skip_entry) into a skip_list again.
*/
list_for_each_safe(skip, tmp, &it->skip_list)
list_del_init(skip);
}
/**
* rtrs_clt_init_req() Initialize an rtrs_clt_io_req holding information
* about an inflight IO.
* The user buffer holding user control message (not data) is copied into
* the corresponding buffer of rtrs_iu (req->iu->buf), which later on will
* also hold the control message of rtrs.
* @req: an io request holding information about IO.
* @sess: client session
* @conf: conformation callback function to notify upper layer.
* @permit: permit for allocation of RDMA remote buffer
* @priv: private pointer
* @vec: kernel vector containing control message
* @usr_len: length of the user message
* @sg: scater list for IO data
* @sg_cnt: number of scater list entries
* @data_len: length of the IO data
* @dir: direction of the IO.
*/
static void rtrs_clt_init_req(struct rtrs_clt_io_req *req,
struct rtrs_clt_sess *sess,
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)
{
struct iov_iter iter;
size_t len;
req->permit = permit;
req->in_use = true;
req->usr_len = usr_len;
req->data_len = data_len;
req->sglist = sg;
req->sg_cnt = sg_cnt;
req->priv = priv;
req->dir = dir;
req->con = rtrs_permit_to_clt_con(sess, permit);
req->conf = conf;
req->need_inv = false;
req->need_inv_comp = false;
req->inv_errno = 0;
iov_iter_kvec(&iter, READ, vec, 1, usr_len);
len = _copy_from_iter(req->iu->buf, usr_len, &iter);
WARN_ON(len != usr_len);
reinit_completion(&req->inv_comp);
}
static struct rtrs_clt_io_req *
rtrs_clt_get_req(struct rtrs_clt_sess *sess,
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)
{
struct rtrs_clt_io_req *req;
req = &sess->reqs[permit->mem_id];
rtrs_clt_init_req(req, sess, conf, permit, priv, vec, usr_len,
sg, sg_cnt, data_len, dir);
return req;
}
static struct rtrs_clt_io_req *
rtrs_clt_get_copy_req(struct rtrs_clt_sess *alive_sess,
struct rtrs_clt_io_req *fail_req)
{
struct rtrs_clt_io_req *req;
struct kvec vec = {
.iov_base = fail_req->iu->buf,
.iov_len = fail_req->usr_len
};
req = &alive_sess->reqs[fail_req->permit->mem_id];
rtrs_clt_init_req(req, alive_sess, fail_req->conf, fail_req->permit,
fail_req->priv, &vec, fail_req->usr_len,
fail_req->sglist, fail_req->sg_cnt,
fail_req->data_len, fail_req->dir);
return req;
}
static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con,
struct rtrs_clt_io_req *req,
struct rtrs_rbuf *rbuf,
u32 size, u32 imm)
{
struct rtrs_clt_sess *sess = to_clt_sess(con->c.sess);
struct ib_sge *sge = req->sge;
enum ib_send_flags flags;
struct scatterlist *sg;
size_t num_sge;
int i;
for_each_sg(req->sglist, sg, req->sg_cnt, i) {
sge[i].addr = sg_dma_address(sg);
sge[i].length = sg_dma_len(sg);
sge[i].lkey = sess->s.dev->ib_pd->local_dma_lkey;
}
sge[i].addr = req->iu->dma_addr;
sge[i].length = size;
sge[i].lkey = sess->s.dev->ib_pd->local_dma_lkey;
num_sge = 1 + req->sg_cnt;
/*
* From time to time we have to post signalled sends,
* or send queue will fill up and only QP reset can help.
*/
flags = atomic_inc_return(&con->io_cnt) % sess->queue_depth ?
0 : IB_SEND_SIGNALED;
ib_dma_sync_single_for_device(sess->s.dev->ib_dev, req->iu->dma_addr,
size, DMA_TO_DEVICE);
return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge,
rbuf->rkey, rbuf->addr, imm,
flags, NULL);
}
static int rtrs_clt_write_req(struct rtrs_clt_io_req *req)
{
struct rtrs_clt_con *con = req->con;
struct rtrs_sess *s = con->c.sess;
struct rtrs_clt_sess *sess = to_clt_sess(s);
struct rtrs_msg_rdma_write *msg;
struct rtrs_rbuf *rbuf;
int ret, count = 0;
u32 imm, buf_id;
const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len;
if (unlikely(tsize > sess->chunk_size)) {
rtrs_wrn(s, "Write request failed, size too big %zu > %d\n",
tsize, sess->chunk_size);
return -EMSGSIZE;
}
if (req->sg_cnt) {
count = ib_dma_map_sg(sess->s.dev->ib_dev, req->sglist,
req->sg_cnt, req->dir);