1
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5
6
7#include <linux/bio.h>
8#include <linux/slab.h>
9#include <linux/jiffies.h>
10#include <linux/dm-dirty-log.h>
11#include <linux/device-mapper.h>
12#include <linux/dm-log-userspace.h>
13#include <linux/module.h>
14#include <linux/workqueue.h>
15
16#include "dm-log-userspace-transfer.h"
17
18#define DM_LOG_USERSPACE_VSN "1.3.0"
19
20#define FLUSH_ENTRY_POOL_SIZE 16
21
22struct dm_dirty_log_flush_entry {
23 int type;
24 region_t region;
25 struct list_head list;
26};
27
28
29
30
31
32
33
34#define MAX_FLUSH_GROUP_COUNT 32
35
36struct log_c {
37 struct dm_target *ti;
38 struct dm_dev *log_dev;
39
40 char *usr_argv_str;
41 uint32_t usr_argc;
42
43 uint32_t region_size;
44 region_t region_count;
45 uint64_t luid;
46 char uuid[DM_UUID_LEN];
47
48
49
50
51
52
53
54 spinlock_t flush_lock;
55 struct list_head mark_list;
56 struct list_head clear_list;
57
58
59
60
61
62
63
64
65 uint64_t in_sync_hint;
66
67
68
69
70 struct workqueue_struct *dmlog_wq;
71 struct delayed_work flush_log_work;
72 atomic_t sched_flush;
73
74
75
76
77 uint32_t integrated_flush;
78
79 mempool_t *flush_entry_pool;
80};
81
82static struct kmem_cache *_flush_entry_cache;
83
84static int userspace_do_request(struct log_c *lc, const char *uuid,
85 int request_type, char *data, size_t data_size,
86 char *rdata, size_t *rdata_size)
87{
88 int r;
89
90
91
92
93
94
95retry:
96 r = dm_consult_userspace(uuid, lc->luid, request_type, data,
97 data_size, rdata, rdata_size);
98
99 if (r != -ESRCH)
100 return r;
101
102 DMERR(" Userspace log server not found.");
103 while (1) {
104 set_current_state(TASK_INTERRUPTIBLE);
105 schedule_timeout(2*HZ);
106 DMWARN("Attempting to contact userspace log server...");
107 r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR,
108 lc->usr_argv_str,
109 strlen(lc->usr_argv_str) + 1,
110 NULL, NULL);
111 if (!r)
112 break;
113 }
114 DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
115 r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL,
116 0, NULL, NULL);
117 if (!r)
118 goto retry;
119
120 DMERR("Error trying to resume userspace log: %d", r);
121
122 return -ESRCH;
123}
124
125static int build_constructor_string(struct dm_target *ti,
126 unsigned argc, char **argv,
127 char **ctr_str)
128{
129 int i, str_size;
130 char *str = NULL;
131
132 *ctr_str = NULL;
133
134
135
136
137 for (i = 0, str_size = 0; i < argc; i++)
138 str_size += strlen(argv[i]) + 1;
139
140 str_size += 20;
141
142 str = kzalloc(str_size, GFP_KERNEL);
143 if (!str) {
144 DMWARN("Unable to allocate memory for constructor string");
145 return -ENOMEM;
146 }
147
148 str_size = sprintf(str, "%llu", (unsigned long long)ti->len);
149 for (i = 0; i < argc; i++)
150 str_size += sprintf(str + str_size, " %s", argv[i]);
151
152 *ctr_str = str;
153 return str_size;
154}
155
156static void do_flush(struct work_struct *work)
157{
158 int r;
159 struct log_c *lc = container_of(work, struct log_c, flush_log_work.work);
160
161 atomic_set(&lc->sched_flush, 0);
162
163 r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, NULL, 0, NULL, NULL);
164
165 if (r)
166 dm_table_event(lc->ti->table);
167}
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
191 unsigned argc, char **argv)
192{
193 int r = 0;
194 int str_size;
195 char *ctr_str = NULL;
196 struct log_c *lc = NULL;
197 uint64_t rdata;
198 size_t rdata_size = sizeof(rdata);
199 char *devices_rdata = NULL;
200 size_t devices_rdata_size = DM_NAME_LEN;
201
202 if (argc < 3) {
203 DMWARN("Too few arguments to userspace dirty log");
204 return -EINVAL;
205 }
206
207 lc = kzalloc(sizeof(*lc), GFP_KERNEL);
208 if (!lc) {
209 DMWARN("Unable to allocate userspace log context.");
210 return -ENOMEM;
211 }
212
213
214 lc->luid = (unsigned long)lc;
215
216 lc->ti = ti;
217
218 if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
219 DMWARN("UUID argument too long.");
220 kfree(lc);
221 return -EINVAL;
222 }
223
224 lc->usr_argc = argc;
225
226 strncpy(lc->uuid, argv[0], DM_UUID_LEN);
227 argc--;
228 argv++;
229 spin_lock_init(&lc->flush_lock);
230 INIT_LIST_HEAD(&lc->mark_list);
231 INIT_LIST_HEAD(&lc->clear_list);
232
233 if (!strcasecmp(argv[0], "integrated_flush")) {
234 lc->integrated_flush = 1;
235 argc--;
236 argv++;
237 }
238
239 str_size = build_constructor_string(ti, argc, argv, &ctr_str);
240 if (str_size < 0) {
241 kfree(lc);
242 return str_size;
243 }
244
245 devices_rdata = kzalloc(devices_rdata_size, GFP_KERNEL);
246 if (!devices_rdata) {
247 DMERR("Failed to allocate memory for device information");
248 r = -ENOMEM;
249 goto out;
250 }
251
252 lc->flush_entry_pool = mempool_create_slab_pool(FLUSH_ENTRY_POOL_SIZE,
253 _flush_entry_cache);
254 if (!lc->flush_entry_pool) {
255 DMERR("Failed to create flush_entry_pool");
256 r = -ENOMEM;
257 goto out;
258 }
259
260
261
262
263 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR,
264 ctr_str, str_size,
265 devices_rdata, &devices_rdata_size);
266
267 if (r < 0) {
268 if (r == -ESRCH)
269 DMERR("Userspace log server not found");
270 else
271 DMERR("Userspace log server failed to create log");
272 goto out;
273 }
274
275
276 rdata_size = sizeof(rdata);
277 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE,
278 NULL, 0, (char *)&rdata, &rdata_size);
279
280 if (r) {
281 DMERR("Failed to get region size of dirty log");
282 goto out;
283 }
284
285 lc->region_size = (uint32_t)rdata;
286 lc->region_count = dm_sector_div_up(ti->len, lc->region_size);
287
288 if (devices_rdata_size) {
289 if (devices_rdata[devices_rdata_size - 1] != '\0') {
290 DMERR("DM_ULOG_CTR device return string not properly terminated");
291 r = -EINVAL;
292 goto out;
293 }
294 r = dm_get_device(ti, devices_rdata,
295 dm_table_get_mode(ti->table), &lc->log_dev);
296 if (r)
297 DMERR("Failed to register %s with device-mapper",
298 devices_rdata);
299 }
300
301 if (lc->integrated_flush) {
302 lc->dmlog_wq = alloc_workqueue("dmlogd", WQ_MEM_RECLAIM, 0);
303 if (!lc->dmlog_wq) {
304 DMERR("couldn't start dmlogd");
305 r = -ENOMEM;
306 goto out;
307 }
308
309 INIT_DELAYED_WORK(&lc->flush_log_work, do_flush);
310 atomic_set(&lc->sched_flush, 0);
311 }
312
313out:
314 kfree(devices_rdata);
315 if (r) {
316 mempool_destroy(lc->flush_entry_pool);
317 kfree(lc);
318 kfree(ctr_str);
319 } else {
320 lc->usr_argv_str = ctr_str;
321 log->context = lc;
322 }
323
324 return r;
325}
326
327static void userspace_dtr(struct dm_dirty_log *log)
328{
329 struct log_c *lc = log->context;
330
331 if (lc->integrated_flush) {
332
333 if (atomic_read(&lc->sched_flush))
334 flush_delayed_work(&lc->flush_log_work);
335
336 destroy_workqueue(lc->dmlog_wq);
337 }
338
339 (void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR,
340 NULL, 0, NULL, NULL);
341
342 if (lc->log_dev)
343 dm_put_device(lc->ti, lc->log_dev);
344
345 mempool_destroy(lc->flush_entry_pool);
346
347 kfree(lc->usr_argv_str);
348 kfree(lc);
349
350 return;
351}
352
353static int userspace_presuspend(struct dm_dirty_log *log)
354{
355 int r;
356 struct log_c *lc = log->context;
357
358 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND,
359 NULL, 0, NULL, NULL);
360
361 return r;
362}
363
364static int userspace_postsuspend(struct dm_dirty_log *log)
365{
366 int r;
367 struct log_c *lc = log->context;
368
369
370
371
372 if (lc->integrated_flush && atomic_read(&lc->sched_flush))
373 flush_delayed_work(&lc->flush_log_work);
374
375 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND,
376 NULL, 0, NULL, NULL);
377
378 return r;
379}
380
381static int userspace_resume(struct dm_dirty_log *log)
382{
383 int r;
384 struct log_c *lc = log->context;
385
386 lc->in_sync_hint = 0;
387 r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME,
388 NULL, 0, NULL, NULL);
389
390 return r;
391}
392
393static uint32_t userspace_get_region_size(struct dm_dirty_log *log)
394{
395 struct log_c *lc = log->context;
396
397 return lc->region_size;
398}
399
400
401
402
403
404
405
406
407
408static int userspace_is_clean(struct dm_dirty_log *log, region_t region)
409{
410 int r;
411 uint64_t region64 = (uint64_t)region;
412 int64_t is_clean;
413 size_t rdata_size;
414 struct log_c *lc = log->context;
415
416 rdata_size = sizeof(is_clean);
417 r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_CLEAN,
418 (char *)®ion64, sizeof(region64),
419 (char *)&is_clean, &rdata_size);
420
421 return (r) ? 0 : (int)is_clean;
422}
423
424
425
426
427
428
429
430
431
432
433
434
435static int userspace_in_sync(struct dm_dirty_log *log, region_t region,
436 int can_block)
437{
438 int r;
439 uint64_t region64 = region;
440 int64_t in_sync;
441 size_t rdata_size;
442 struct log_c *lc = log->context;
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457 if (!can_block)
458 return -EWOULDBLOCK;
459
460 rdata_size = sizeof(in_sync);
461 r = userspace_do_request(lc, lc->uuid, DM_ULOG_IN_SYNC,
462 (char *)®ion64, sizeof(region64),
463 (char *)&in_sync, &rdata_size);
464 return (r) ? 0 : (int)in_sync;
465}
466
467static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list)
468{
469 int r = 0;
470 struct dm_dirty_log_flush_entry *fe;
471
472 list_for_each_entry(fe, flush_list, list) {
473 r = userspace_do_request(lc, lc->uuid, fe->type,
474 (char *)&fe->region,
475 sizeof(fe->region),
476 NULL, NULL);
477 if (r)
478 break;
479 }
480
481 return r;
482}
483
484static int flush_by_group(struct log_c *lc, struct list_head *flush_list,
485 int flush_with_payload)
486{
487 int r = 0;
488 int count;
489 uint32_t type = 0;
490 struct dm_dirty_log_flush_entry *fe, *tmp_fe;
491 LIST_HEAD(tmp_list);
492 uint64_t group[MAX_FLUSH_GROUP_COUNT];
493
494
495
496
497 while (!list_empty(flush_list)) {
498 count = 0;
499
500 list_for_each_entry_safe(fe, tmp_fe, flush_list, list) {
501 group[count] = fe->region;
502 count++;
503
504 list_move(&fe->list, &tmp_list);
505
506 type = fe->type;
507 if (count >= MAX_FLUSH_GROUP_COUNT)
508 break;
509 }
510
511 if (flush_with_payload) {
512 r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
513 (char *)(group),
514 count * sizeof(uint64_t),
515 NULL, NULL);
516
517
518
519 if (r)
520 break;
521 } else {
522 r = userspace_do_request(lc, lc->uuid, type,
523 (char *)(group),
524 count * sizeof(uint64_t),
525 NULL, NULL);
526 if (r) {
527
528
529
530 list_splice_init(&tmp_list, flush_list);
531 r = flush_one_by_one(lc, flush_list);
532 break;
533 }
534 }
535 }
536
537
538
539
540
541 list_splice_init(&tmp_list, flush_list);
542
543 return r;
544}
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563static int userspace_flush(struct dm_dirty_log *log)
564{
565 int r = 0;
566 unsigned long flags;
567 struct log_c *lc = log->context;
568 LIST_HEAD(mark_list);
569 LIST_HEAD(clear_list);
570 int mark_list_is_empty;
571 int clear_list_is_empty;
572 struct dm_dirty_log_flush_entry *fe, *tmp_fe;
573 mempool_t *flush_entry_pool = lc->flush_entry_pool;
574
575 spin_lock_irqsave(&lc->flush_lock, flags);
576 list_splice_init(&lc->mark_list, &mark_list);
577 list_splice_init(&lc->clear_list, &clear_list);
578 spin_unlock_irqrestore(&lc->flush_lock, flags);
579
580 mark_list_is_empty = list_empty(&mark_list);
581 clear_list_is_empty = list_empty(&clear_list);
582
583 if (mark_list_is_empty && clear_list_is_empty)
584 return 0;
585
586 r = flush_by_group(lc, &clear_list, 0);
587 if (r)
588 goto out;
589
590 if (!lc->integrated_flush) {
591 r = flush_by_group(lc, &mark_list, 0);
592 if (r)
593 goto out;
594 r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
595 NULL, 0, NULL, NULL);
596 goto out;
597 }
598
599
600
601
602 r = flush_by_group(lc, &mark_list, 1);
603 if (r)
604 goto out;
605
606 if (mark_list_is_empty && !atomic_read(&lc->sched_flush)) {
607
608
609
610
611 queue_delayed_work(lc->dmlog_wq, &lc->flush_log_work, 3 * HZ);
612 atomic_set(&lc->sched_flush, 1);
613 } else {
614
615
616
617
618 cancel_delayed_work(&lc->flush_log_work);
619 atomic_set(&lc->sched_flush, 0);
620 }
621
622out:
623
624
625
626
627
628 list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) {
629 list_del(&fe->list);
630 mempool_free(fe, flush_entry_pool);
631 }
632 list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) {
633 list_del(&fe->list);
634 mempool_free(fe, flush_entry_pool);
635 }
636
637 if (r)
638 dm_table_event(lc->ti->table);
639
640 return r;
641}
642
643
644
645
646
647
648
649static void userspace_mark_region(struct dm_dirty_log *log, region_t region)
650{
651 unsigned long flags;
652 struct log_c *lc = log->context;
653 struct dm_dirty_log_flush_entry *fe;
654
655
656 fe = mempool_alloc(lc->flush_entry_pool, GFP_NOIO);
657 BUG_ON(!fe);
658
659 spin_lock_irqsave(&lc->flush_lock, flags);
660 fe->type = DM_ULOG_MARK_REGION;
661 fe->region = region;
662 list_add(&fe->list, &lc->mark_list);
663 spin_unlock_irqrestore(&lc->flush_lock, flags);
664
665 return;
666}
667
668
669
670
671
672
673
674
675
676
677
678static void userspace_clear_region(struct dm_dirty_log *log, region_t region)
679{
680 unsigned long flags;
681 struct log_c *lc = log->context;
682 struct dm_dirty_log_flush_entry *fe;
683
684
685
686
687
688
689
690 fe = mempool_alloc(lc->flush_entry_pool, GFP_ATOMIC);
691 if (!fe) {
692 DMERR("Failed to allocate memory to clear region.");
693 return;
694 }
695
696 spin_lock_irqsave(&lc->flush_lock, flags);
697 fe->type = DM_ULOG_CLEAR_REGION;
698 fe->region = region;
699 list_add(&fe->list, &lc->clear_list);
700 spin_unlock_irqrestore(&lc->flush_lock, flags);
701
702 return;
703}
704
705
706
707
708
709
710
711
712
713static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region)
714{
715 int r;
716 size_t rdata_size;
717 struct log_c *lc = log->context;
718 struct {
719 int64_t i;
720 region_t r;
721 } pkg;
722
723 if (lc->in_sync_hint >= lc->region_count)
724 return 0;
725
726 rdata_size = sizeof(pkg);
727 r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK,
728 NULL, 0, (char *)&pkg, &rdata_size);
729
730 *region = pkg.r;
731 return (r) ? r : (int)pkg.i;
732}
733
734
735
736
737
738
739
740static void userspace_set_region_sync(struct dm_dirty_log *log,
741 region_t region, int in_sync)
742{
743 struct log_c *lc = log->context;
744 struct {
745 region_t r;
746 int64_t i;
747 } pkg;
748
749 pkg.r = region;
750 pkg.i = (int64_t)in_sync;
751
752 (void) userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC,
753 (char *)&pkg, sizeof(pkg), NULL, NULL);
754
755
756
757
758
759 return;
760}
761
762
763
764
765
766
767
768
769
770static region_t userspace_get_sync_count(struct dm_dirty_log *log)
771{
772 int r;
773 size_t rdata_size;
774 uint64_t sync_count;
775 struct log_c *lc = log->context;
776
777 rdata_size = sizeof(sync_count);
778 r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT,
779 NULL, 0, (char *)&sync_count, &rdata_size);
780
781 if (r)
782 return 0;
783
784 if (sync_count >= lc->region_count)
785 lc->in_sync_hint = lc->region_count;
786
787 return (region_t)sync_count;
788}
789
790
791
792
793
794
795static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
796 char *result, unsigned maxlen)
797{
798 int r = 0;
799 char *table_args;
800 size_t sz = (size_t)maxlen;
801 struct log_c *lc = log->context;
802
803 switch (status_type) {
804 case STATUSTYPE_INFO:
805 r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO,
806 NULL, 0, result, &sz);
807
808 if (r) {
809 sz = 0;
810 DMEMIT("%s 1 COM_FAILURE", log->type->name);
811 }
812 break;
813 case STATUSTYPE_TABLE:
814 sz = 0;
815 table_args = strchr(lc->usr_argv_str, ' ');
816 BUG_ON(!table_args);
817 table_args++;
818
819 DMEMIT("%s %u %s ", log->type->name, lc->usr_argc, lc->uuid);
820 if (lc->integrated_flush)
821 DMEMIT("integrated_flush ");
822 DMEMIT("%s ", table_args);
823 break;
824 }
825 return (r) ? 0 : (int)sz;
826}
827
828
829
830
831
832
833static int userspace_is_remote_recovering(struct dm_dirty_log *log,
834 region_t region)
835{
836 int r;
837 uint64_t region64 = region;
838 struct log_c *lc = log->context;
839 static unsigned long limit;
840 struct {
841 int64_t is_recovering;
842 uint64_t in_sync_hint;
843 } pkg;
844 size_t rdata_size = sizeof(pkg);
845
846
847
848
849
850
851
852
853 if (region < lc->in_sync_hint)
854 return 0;
855 else if (time_after(limit, jiffies))
856 return 1;
857
858 limit = jiffies + (HZ / 4);
859 r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_REMOTE_RECOVERING,
860 (char *)®ion64, sizeof(region64),
861 (char *)&pkg, &rdata_size);
862 if (r)
863 return 1;
864
865 lc->in_sync_hint = pkg.in_sync_hint;
866
867 return (int)pkg.is_recovering;
868}
869
870static struct dm_dirty_log_type _userspace_type = {
871 .name = "userspace",
872 .module = THIS_MODULE,
873 .ctr = userspace_ctr,
874 .dtr = userspace_dtr,
875 .presuspend = userspace_presuspend,
876 .postsuspend = userspace_postsuspend,
877 .resume = userspace_resume,
878 .get_region_size = userspace_get_region_size,
879 .is_clean = userspace_is_clean,
880 .in_sync = userspace_in_sync,
881 .flush = userspace_flush,
882 .mark_region = userspace_mark_region,
883 .clear_region = userspace_clear_region,
884 .get_resync_work = userspace_get_resync_work,
885 .set_region_sync = userspace_set_region_sync,
886 .get_sync_count = userspace_get_sync_count,
887 .status = userspace_status,
888 .is_remote_recovering = userspace_is_remote_recovering,
889};
890
891static int __init userspace_dirty_log_init(void)
892{
893 int r = 0;
894
895 _flush_entry_cache = KMEM_CACHE(dm_dirty_log_flush_entry, 0);
896 if (!_flush_entry_cache) {
897 DMWARN("Unable to create flush_entry_cache: No memory.");
898 return -ENOMEM;
899 }
900
901 r = dm_ulog_tfr_init();
902 if (r) {
903 DMWARN("Unable to initialize userspace log communications");
904 kmem_cache_destroy(_flush_entry_cache);
905 return r;
906 }
907
908 r = dm_dirty_log_type_register(&_userspace_type);
909 if (r) {
910 DMWARN("Couldn't register userspace dirty log type");
911 dm_ulog_tfr_exit();
912 kmem_cache_destroy(_flush_entry_cache);
913 return r;
914 }
915
916 DMINFO("version " DM_LOG_USERSPACE_VSN " loaded");
917 return 0;
918}
919
920static void __exit userspace_dirty_log_exit(void)
921{
922 dm_dirty_log_type_unregister(&_userspace_type);
923 dm_ulog_tfr_exit();
924 kmem_cache_destroy(_flush_entry_cache);
925
926 DMINFO("version " DM_LOG_USERSPACE_VSN " unloaded");
927 return;
928}
929
930module_init(userspace_dirty_log_init);
931module_exit(userspace_dirty_log_exit);
932
933MODULE_DESCRIPTION(DM_NAME " userspace dirty log link");
934MODULE_AUTHOR("Jonathan Brassow <dm-devel@redhat.com>");
935MODULE_LICENSE("GPL");
936