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6
7
8#include "dm-bio-record.h"
9
10#include <linux/init.h>
11#include <linux/mempool.h>
12#include <linux/module.h>
13#include <linux/pagemap.h>
14#include <linux/slab.h>
15#include <linux/workqueue.h>
16#include <linux/device-mapper.h>
17#include <linux/dm-io.h>
18#include <linux/dm-dirty-log.h>
19#include <linux/dm-kcopyd.h>
20#include <linux/dm-region-hash.h>
21
22#define DM_MSG_PREFIX "raid1"
23
24#define MAX_RECOVERY 1
25
26#define DM_RAID1_HANDLE_ERRORS 0x01
27#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
28
29static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
30
31
32
33
34enum dm_raid1_error {
35 DM_RAID1_WRITE_ERROR,
36 DM_RAID1_FLUSH_ERROR,
37 DM_RAID1_SYNC_ERROR,
38 DM_RAID1_READ_ERROR
39};
40
41struct mirror {
42 struct mirror_set *ms;
43 atomic_t error_count;
44 unsigned long error_type;
45 struct dm_dev *dev;
46 sector_t offset;
47};
48
49struct mirror_set {
50 struct dm_target *ti;
51 struct list_head list;
52
53 uint64_t features;
54
55 spinlock_t lock;
56 struct bio_list reads;
57 struct bio_list writes;
58 struct bio_list failures;
59 struct bio_list holds;
60
61 struct dm_region_hash *rh;
62 struct dm_kcopyd_client *kcopyd_client;
63 struct dm_io_client *io_client;
64
65
66 region_t nr_regions;
67 int in_sync;
68 int log_failure;
69 int leg_failure;
70 atomic_t suspend;
71
72 atomic_t default_mirror;
73
74 struct workqueue_struct *kmirrord_wq;
75 struct work_struct kmirrord_work;
76 struct timer_list timer;
77 unsigned long timer_pending;
78
79 struct work_struct trigger_event;
80
81 unsigned nr_mirrors;
82 struct mirror mirror[0];
83};
84
85DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(raid1_resync_throttle,
86 "A percentage of time allocated for raid resynchronization");
87
88static void wakeup_mirrord(void *context)
89{
90 struct mirror_set *ms = context;
91
92 queue_work(ms->kmirrord_wq, &ms->kmirrord_work);
93}
94
95static void delayed_wake_fn(unsigned long data)
96{
97 struct mirror_set *ms = (struct mirror_set *) data;
98
99 clear_bit(0, &ms->timer_pending);
100 wakeup_mirrord(ms);
101}
102
103static void delayed_wake(struct mirror_set *ms)
104{
105 if (test_and_set_bit(0, &ms->timer_pending))
106 return;
107
108 ms->timer.expires = jiffies + HZ / 5;
109 ms->timer.data = (unsigned long) ms;
110 ms->timer.function = delayed_wake_fn;
111 add_timer(&ms->timer);
112}
113
114static void wakeup_all_recovery_waiters(void *context)
115{
116 wake_up_all(&_kmirrord_recovery_stopped);
117}
118
119static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw)
120{
121 unsigned long flags;
122 int should_wake = 0;
123 struct bio_list *bl;
124
125 bl = (rw == WRITE) ? &ms->writes : &ms->reads;
126 spin_lock_irqsave(&ms->lock, flags);
127 should_wake = !(bl->head);
128 bio_list_add(bl, bio);
129 spin_unlock_irqrestore(&ms->lock, flags);
130
131 if (should_wake)
132 wakeup_mirrord(ms);
133}
134
135static void dispatch_bios(void *context, struct bio_list *bio_list)
136{
137 struct mirror_set *ms = context;
138 struct bio *bio;
139
140 while ((bio = bio_list_pop(bio_list)))
141 queue_bio(ms, bio, WRITE);
142}
143
144struct dm_raid1_bio_record {
145 struct mirror *m;
146
147 struct dm_bio_details details;
148 region_t write_region;
149};
150
151
152
153
154#define DEFAULT_MIRROR 0
155
156
157
158
159
160
161static struct mirror *bio_get_m(struct bio *bio)
162{
163 return (struct mirror *) bio->bi_next;
164}
165
166static void bio_set_m(struct bio *bio, struct mirror *m)
167{
168 bio->bi_next = (struct bio *) m;
169}
170
171static struct mirror *get_default_mirror(struct mirror_set *ms)
172{
173 return &ms->mirror[atomic_read(&ms->default_mirror)];
174}
175
176static void set_default_mirror(struct mirror *m)
177{
178 struct mirror_set *ms = m->ms;
179 struct mirror *m0 = &(ms->mirror[0]);
180
181 atomic_set(&ms->default_mirror, m - m0);
182}
183
184static struct mirror *get_valid_mirror(struct mirror_set *ms)
185{
186 struct mirror *m;
187
188 for (m = ms->mirror; m < ms->mirror + ms->nr_mirrors; m++)
189 if (!atomic_read(&m->error_count))
190 return m;
191
192 return NULL;
193}
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type)
210{
211 struct mirror_set *ms = m->ms;
212 struct mirror *new;
213
214 ms->leg_failure = 1;
215
216
217
218
219
220
221 atomic_inc(&m->error_count);
222
223 if (test_and_set_bit(error_type, &m->error_type))
224 return;
225
226 if (!errors_handled(ms))
227 return;
228
229 if (m != get_default_mirror(ms))
230 goto out;
231
232 if (!ms->in_sync) {
233
234
235
236
237 DMERR("Primary mirror (%s) failed while out-of-sync: "
238 "Reads may fail.", m->dev->name);
239 goto out;
240 }
241
242 new = get_valid_mirror(ms);
243 if (new)
244 set_default_mirror(new);
245 else
246 DMWARN("All sides of mirror have failed.");
247
248out:
249 schedule_work(&ms->trigger_event);
250}
251
252static int mirror_flush(struct dm_target *ti)
253{
254 struct mirror_set *ms = ti->private;
255 unsigned long error_bits;
256
257 unsigned int i;
258 struct dm_io_region io[ms->nr_mirrors];
259 struct mirror *m;
260 struct dm_io_request io_req = {
261 .bi_rw = WRITE_FLUSH,
262 .mem.type = DM_IO_KMEM,
263 .mem.ptr.addr = NULL,
264 .client = ms->io_client,
265 };
266
267 for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) {
268 io[i].bdev = m->dev->bdev;
269 io[i].sector = 0;
270 io[i].count = 0;
271 }
272
273 error_bits = -1;
274 dm_io(&io_req, ms->nr_mirrors, io, &error_bits);
275 if (unlikely(error_bits != 0)) {
276 for (i = 0; i < ms->nr_mirrors; i++)
277 if (test_bit(i, &error_bits))
278 fail_mirror(ms->mirror + i,
279 DM_RAID1_FLUSH_ERROR);
280 return -EIO;
281 }
282
283 return 0;
284}
285
286
287
288
289
290
291
292
293static void recovery_complete(int read_err, unsigned long write_err,
294 void *context)
295{
296 struct dm_region *reg = context;
297 struct mirror_set *ms = dm_rh_region_context(reg);
298 int m, bit = 0;
299
300 if (read_err) {
301
302 DMERR_LIMIT("Unable to read primary mirror during recovery");
303 fail_mirror(get_default_mirror(ms), DM_RAID1_SYNC_ERROR);
304 }
305
306 if (write_err) {
307 DMERR_LIMIT("Write error during recovery (error = 0x%lx)",
308 write_err);
309
310
311
312
313 for (m = 0; m < ms->nr_mirrors; m++) {
314 if (&ms->mirror[m] == get_default_mirror(ms))
315 continue;
316 if (test_bit(bit, &write_err))
317 fail_mirror(ms->mirror + m,
318 DM_RAID1_SYNC_ERROR);
319 bit++;
320 }
321 }
322
323 dm_rh_recovery_end(reg, !(read_err || write_err));
324}
325
326static int recover(struct mirror_set *ms, struct dm_region *reg)
327{
328 int r;
329 unsigned i;
330 struct dm_io_region from, to[DM_KCOPYD_MAX_REGIONS], *dest;
331 struct mirror *m;
332 unsigned long flags = 0;
333 region_t key = dm_rh_get_region_key(reg);
334 sector_t region_size = dm_rh_get_region_size(ms->rh);
335
336
337 m = get_default_mirror(ms);
338 from.bdev = m->dev->bdev;
339 from.sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
340 if (key == (ms->nr_regions - 1)) {
341
342
343
344
345 from.count = ms->ti->len & (region_size - 1);
346 if (!from.count)
347 from.count = region_size;
348 } else
349 from.count = region_size;
350
351
352 for (i = 0, dest = to; i < ms->nr_mirrors; i++) {
353 if (&ms->mirror[i] == get_default_mirror(ms))
354 continue;
355
356 m = ms->mirror + i;
357 dest->bdev = m->dev->bdev;
358 dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
359 dest->count = from.count;
360 dest++;
361 }
362
363
364 if (!errors_handled(ms))
365 set_bit(DM_KCOPYD_IGNORE_ERROR, &flags);
366
367 r = dm_kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to,
368 flags, recovery_complete, reg);
369
370 return r;
371}
372
373static void do_recovery(struct mirror_set *ms)
374{
375 struct dm_region *reg;
376 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
377 int r;
378
379
380
381
382 dm_rh_recovery_prepare(ms->rh);
383
384
385
386
387 while ((reg = dm_rh_recovery_start(ms->rh))) {
388 r = recover(ms, reg);
389 if (r)
390 dm_rh_recovery_end(reg, 0);
391 }
392
393
394
395
396 if (!ms->in_sync &&
397 (log->type->get_sync_count(log) == ms->nr_regions)) {
398
399 dm_table_event(ms->ti->table);
400 ms->in_sync = 1;
401 }
402}
403
404
405
406
407static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)
408{
409 struct mirror *m = get_default_mirror(ms);
410
411 do {
412 if (likely(!atomic_read(&m->error_count)))
413 return m;
414
415 if (m-- == ms->mirror)
416 m += ms->nr_mirrors;
417 } while (m != get_default_mirror(ms));
418
419 return NULL;
420}
421
422static int default_ok(struct mirror *m)
423{
424 struct mirror *default_mirror = get_default_mirror(m->ms);
425
426 return !atomic_read(&default_mirror->error_count);
427}
428
429static int mirror_available(struct mirror_set *ms, struct bio *bio)
430{
431 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
432 region_t region = dm_rh_bio_to_region(ms->rh, bio);
433
434 if (log->type->in_sync(log, region, 0))
435 return choose_mirror(ms, bio->bi_sector) ? 1 : 0;
436
437 return 0;
438}
439
440
441
442
443static sector_t map_sector(struct mirror *m, struct bio *bio)
444{
445 if (unlikely(!bio->bi_size))
446 return 0;
447 return m->offset + dm_target_offset(m->ms->ti, bio->bi_sector);
448}
449
450static void map_bio(struct mirror *m, struct bio *bio)
451{
452 bio->bi_bdev = m->dev->bdev;
453 bio->bi_sector = map_sector(m, bio);
454}
455
456static void map_region(struct dm_io_region *io, struct mirror *m,
457 struct bio *bio)
458{
459 io->bdev = m->dev->bdev;
460 io->sector = map_sector(m, bio);
461 io->count = bio_sectors(bio);
462}
463
464static void hold_bio(struct mirror_set *ms, struct bio *bio)
465{
466
467
468
469
470 spin_lock_irq(&ms->lock);
471
472 if (atomic_read(&ms->suspend)) {
473 spin_unlock_irq(&ms->lock);
474
475
476
477
478 if (dm_noflush_suspending(ms->ti))
479 bio_endio(bio, DM_ENDIO_REQUEUE);
480 else
481 bio_endio(bio, -EIO);
482 return;
483 }
484
485
486
487
488 bio_list_add(&ms->holds, bio);
489 spin_unlock_irq(&ms->lock);
490}
491
492
493
494
495static void read_callback(unsigned long error, void *context)
496{
497 struct bio *bio = context;
498 struct mirror *m;
499
500 m = bio_get_m(bio);
501 bio_set_m(bio, NULL);
502
503 if (likely(!error)) {
504 bio_endio(bio, 0);
505 return;
506 }
507
508 fail_mirror(m, DM_RAID1_READ_ERROR);
509
510 if (likely(default_ok(m)) || mirror_available(m->ms, bio)) {
511 DMWARN_LIMIT("Read failure on mirror device %s. "
512 "Trying alternative device.",
513 m->dev->name);
514 queue_bio(m->ms, bio, bio_rw(bio));
515 return;
516 }
517
518 DMERR_LIMIT("Read failure on mirror device %s. Failing I/O.",
519 m->dev->name);
520 bio_endio(bio, -EIO);
521}
522
523
524static void read_async_bio(struct mirror *m, struct bio *bio)
525{
526 struct dm_io_region io;
527 struct dm_io_request io_req = {
528 .bi_rw = READ,
529 .mem.type = DM_IO_BVEC,
530 .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
531 .notify.fn = read_callback,
532 .notify.context = bio,
533 .client = m->ms->io_client,
534 };
535
536 map_region(&io, m, bio);
537 bio_set_m(bio, m);
538 BUG_ON(dm_io(&io_req, 1, &io, NULL));
539}
540
541static inline int region_in_sync(struct mirror_set *ms, region_t region,
542 int may_block)
543{
544 int state = dm_rh_get_state(ms->rh, region, may_block);
545 return state == DM_RH_CLEAN || state == DM_RH_DIRTY;
546}
547
548static void do_reads(struct mirror_set *ms, struct bio_list *reads)
549{
550 region_t region;
551 struct bio *bio;
552 struct mirror *m;
553
554 while ((bio = bio_list_pop(reads))) {
555 region = dm_rh_bio_to_region(ms->rh, bio);
556 m = get_default_mirror(ms);
557
558
559
560
561 if (likely(region_in_sync(ms, region, 1)))
562 m = choose_mirror(ms, bio->bi_sector);
563 else if (m && atomic_read(&m->error_count))
564 m = NULL;
565
566 if (likely(m))
567 read_async_bio(m, bio);
568 else
569 bio_endio(bio, -EIO);
570 }
571}
572
573
574
575
576
577
578
579
580
581
582
583
584
585static void write_callback(unsigned long error, void *context)
586{
587 unsigned i, ret = 0;
588 struct bio *bio = (struct bio *) context;
589 struct mirror_set *ms;
590 int should_wake = 0;
591 unsigned long flags;
592
593 ms = bio_get_m(bio)->ms;
594 bio_set_m(bio, NULL);
595
596
597
598
599
600
601
602 if (likely(!error)) {
603 bio_endio(bio, ret);
604 return;
605 }
606
607 for (i = 0; i < ms->nr_mirrors; i++)
608 if (test_bit(i, &error))
609 fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR);
610
611
612
613
614
615
616 spin_lock_irqsave(&ms->lock, flags);
617 if (!ms->failures.head)
618 should_wake = 1;
619 bio_list_add(&ms->failures, bio);
620 spin_unlock_irqrestore(&ms->lock, flags);
621 if (should_wake)
622 wakeup_mirrord(ms);
623}
624
625static void do_write(struct mirror_set *ms, struct bio *bio)
626{
627 unsigned int i;
628 struct dm_io_region io[ms->nr_mirrors], *dest = io;
629 struct mirror *m;
630 struct dm_io_request io_req = {
631 .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
632 .mem.type = DM_IO_BVEC,
633 .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
634 .notify.fn = write_callback,
635 .notify.context = bio,
636 .client = ms->io_client,
637 };
638
639 if (bio->bi_rw & REQ_DISCARD) {
640 io_req.bi_rw |= REQ_DISCARD;
641 io_req.mem.type = DM_IO_KMEM;
642 io_req.mem.ptr.addr = NULL;
643 }
644
645 for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++)
646 map_region(dest++, m, bio);
647
648
649
650
651
652 bio_set_m(bio, get_default_mirror(ms));
653
654 BUG_ON(dm_io(&io_req, ms->nr_mirrors, io, NULL));
655}
656
657static void do_writes(struct mirror_set *ms, struct bio_list *writes)
658{
659 int state;
660 struct bio *bio;
661 struct bio_list sync, nosync, recover, *this_list = NULL;
662 struct bio_list requeue;
663 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
664 region_t region;
665
666 if (!writes->head)
667 return;
668
669
670
671
672 bio_list_init(&sync);
673 bio_list_init(&nosync);
674 bio_list_init(&recover);
675 bio_list_init(&requeue);
676
677 while ((bio = bio_list_pop(writes))) {
678 if ((bio->bi_rw & REQ_FLUSH) ||
679 (bio->bi_rw & REQ_DISCARD)) {
680 bio_list_add(&sync, bio);
681 continue;
682 }
683
684 region = dm_rh_bio_to_region(ms->rh, bio);
685
686 if (log->type->is_remote_recovering &&
687 log->type->is_remote_recovering(log, region)) {
688 bio_list_add(&requeue, bio);
689 continue;
690 }
691
692 state = dm_rh_get_state(ms->rh, region, 1);
693 switch (state) {
694 case DM_RH_CLEAN:
695 case DM_RH_DIRTY:
696 this_list = &sync;
697 break;
698
699 case DM_RH_NOSYNC:
700 this_list = &nosync;
701 break;
702
703 case DM_RH_RECOVERING:
704 this_list = &recover;
705 break;
706 }
707
708 bio_list_add(this_list, bio);
709 }
710
711
712
713
714
715 if (unlikely(requeue.head)) {
716 spin_lock_irq(&ms->lock);
717 bio_list_merge(&ms->writes, &requeue);
718 spin_unlock_irq(&ms->lock);
719 delayed_wake(ms);
720 }
721
722
723
724
725
726
727 dm_rh_inc_pending(ms->rh, &sync);
728 dm_rh_inc_pending(ms->rh, &nosync);
729
730
731
732
733
734
735 ms->log_failure = dm_rh_flush(ms->rh) ? 1 : ms->log_failure;
736
737
738
739
740 if (unlikely(ms->log_failure) && errors_handled(ms)) {
741 spin_lock_irq(&ms->lock);
742 bio_list_merge(&ms->failures, &sync);
743 spin_unlock_irq(&ms->lock);
744 wakeup_mirrord(ms);
745 } else
746 while ((bio = bio_list_pop(&sync)))
747 do_write(ms, bio);
748
749 while ((bio = bio_list_pop(&recover)))
750 dm_rh_delay(ms->rh, bio);
751
752 while ((bio = bio_list_pop(&nosync))) {
753 if (unlikely(ms->leg_failure) && errors_handled(ms)) {
754 spin_lock_irq(&ms->lock);
755 bio_list_add(&ms->failures, bio);
756 spin_unlock_irq(&ms->lock);
757 wakeup_mirrord(ms);
758 } else {
759 map_bio(get_default_mirror(ms), bio);
760 generic_make_request(bio);
761 }
762 }
763}
764
765static void do_failures(struct mirror_set *ms, struct bio_list *failures)
766{
767 struct bio *bio;
768
769 if (likely(!failures->head))
770 return;
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789 while ((bio = bio_list_pop(failures))) {
790 if (!ms->log_failure) {
791 ms->in_sync = 0;
792 dm_rh_mark_nosync(ms->rh, bio);
793 }
794
795
796
797
798
799
800
801
802
803 if (!get_valid_mirror(ms))
804 bio_endio(bio, -EIO);
805 else if (errors_handled(ms))
806 hold_bio(ms, bio);
807 else
808 bio_endio(bio, 0);
809 }
810}
811
812static void trigger_event(struct work_struct *work)
813{
814 struct mirror_set *ms =
815 container_of(work, struct mirror_set, trigger_event);
816
817 dm_table_event(ms->ti->table);
818}
819
820
821
822
823static void do_mirror(struct work_struct *work)
824{
825 struct mirror_set *ms = container_of(work, struct mirror_set,
826 kmirrord_work);
827 struct bio_list reads, writes, failures;
828 unsigned long flags;
829
830 spin_lock_irqsave(&ms->lock, flags);
831 reads = ms->reads;
832 writes = ms->writes;
833 failures = ms->failures;
834 bio_list_init(&ms->reads);
835 bio_list_init(&ms->writes);
836 bio_list_init(&ms->failures);
837 spin_unlock_irqrestore(&ms->lock, flags);
838
839 dm_rh_update_states(ms->rh, errors_handled(ms));
840 do_recovery(ms);
841 do_reads(ms, &reads);
842 do_writes(ms, &writes);
843 do_failures(ms, &failures);
844}
845
846
847
848
849static struct mirror_set *alloc_context(unsigned int nr_mirrors,
850 uint32_t region_size,
851 struct dm_target *ti,
852 struct dm_dirty_log *dl)
853{
854 size_t len;
855 struct mirror_set *ms = NULL;
856
857 len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors);
858
859 ms = kzalloc(len, GFP_KERNEL);
860 if (!ms) {
861 ti->error = "Cannot allocate mirror context";
862 return NULL;
863 }
864
865 spin_lock_init(&ms->lock);
866 bio_list_init(&ms->reads);
867 bio_list_init(&ms->writes);
868 bio_list_init(&ms->failures);
869 bio_list_init(&ms->holds);
870
871 ms->ti = ti;
872 ms->nr_mirrors = nr_mirrors;
873 ms->nr_regions = dm_sector_div_up(ti->len, region_size);
874 ms->in_sync = 0;
875 ms->log_failure = 0;
876 ms->leg_failure = 0;
877 atomic_set(&ms->suspend, 0);
878 atomic_set(&ms->default_mirror, DEFAULT_MIRROR);
879
880 ms->io_client = dm_io_client_create();
881 if (IS_ERR(ms->io_client)) {
882 ti->error = "Error creating dm_io client";
883 kfree(ms);
884 return NULL;
885 }
886
887 ms->rh = dm_region_hash_create(ms, dispatch_bios, wakeup_mirrord,
888 wakeup_all_recovery_waiters,
889 ms->ti->begin, MAX_RECOVERY,
890 dl, region_size, ms->nr_regions);
891 if (IS_ERR(ms->rh)) {
892 ti->error = "Error creating dirty region hash";
893 dm_io_client_destroy(ms->io_client);
894 kfree(ms);
895 return NULL;
896 }
897
898 return ms;
899}
900
901static void free_context(struct mirror_set *ms, struct dm_target *ti,
902 unsigned int m)
903{
904 while (m--)
905 dm_put_device(ti, ms->mirror[m].dev);
906
907 dm_io_client_destroy(ms->io_client);
908 dm_region_hash_destroy(ms->rh);
909 kfree(ms);
910}
911
912static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
913 unsigned int mirror, char **argv)
914{
915 unsigned long long offset;
916 char dummy;
917
918 if (sscanf(argv[1], "%llu%c", &offset, &dummy) != 1) {
919 ti->error = "Invalid offset";
920 return -EINVAL;
921 }
922
923 if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
924 &ms->mirror[mirror].dev)) {
925 ti->error = "Device lookup failure";
926 return -ENXIO;
927 }
928
929 ms->mirror[mirror].ms = ms;
930 atomic_set(&(ms->mirror[mirror].error_count), 0);
931 ms->mirror[mirror].error_type = 0;
932 ms->mirror[mirror].offset = offset;
933
934 return 0;
935}
936
937
938
939
940static struct dm_dirty_log *create_dirty_log(struct dm_target *ti,
941 unsigned argc, char **argv,
942 unsigned *args_used)
943{
944 unsigned param_count;
945 struct dm_dirty_log *dl;
946 char dummy;
947
948 if (argc < 2) {
949 ti->error = "Insufficient mirror log arguments";
950 return NULL;
951 }
952
953 if (sscanf(argv[1], "%u%c", ¶m_count, &dummy) != 1) {
954 ti->error = "Invalid mirror log argument count";
955 return NULL;
956 }
957
958 *args_used = 2 + param_count;
959
960 if (argc < *args_used) {
961 ti->error = "Insufficient mirror log arguments";
962 return NULL;
963 }
964
965 dl = dm_dirty_log_create(argv[0], ti, mirror_flush, param_count,
966 argv + 2);
967 if (!dl) {
968 ti->error = "Error creating mirror dirty log";
969 return NULL;
970 }
971
972 return dl;
973}
974
975static int parse_features(struct mirror_set *ms, unsigned argc, char **argv,
976 unsigned *args_used)
977{
978 unsigned num_features;
979 struct dm_target *ti = ms->ti;
980 char dummy;
981
982 *args_used = 0;
983
984 if (!argc)
985 return 0;
986
987 if (sscanf(argv[0], "%u%c", &num_features, &dummy) != 1) {
988 ti->error = "Invalid number of features";
989 return -EINVAL;
990 }
991
992 argc--;
993 argv++;
994 (*args_used)++;
995
996 if (num_features > argc) {
997 ti->error = "Not enough arguments to support feature count";
998 return -EINVAL;
999 }
1000
1001 if (!strcmp("handle_errors", argv[0]))
1002 ms->features |= DM_RAID1_HANDLE_ERRORS;
1003 else {
1004 ti->error = "Unrecognised feature requested";
1005 return -EINVAL;
1006 }
1007
1008 (*args_used)++;
1009
1010 return 0;
1011}
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1026{
1027 int r;
1028 unsigned int nr_mirrors, m, args_used;
1029 struct mirror_set *ms;
1030 struct dm_dirty_log *dl;
1031 char dummy;
1032
1033 dl = create_dirty_log(ti, argc, argv, &args_used);
1034 if (!dl)
1035 return -EINVAL;
1036
1037 argv += args_used;
1038 argc -= args_used;
1039
1040 if (!argc || sscanf(argv[0], "%u%c", &nr_mirrors, &dummy) != 1 ||
1041 nr_mirrors < 2 || nr_mirrors > DM_KCOPYD_MAX_REGIONS + 1) {
1042 ti->error = "Invalid number of mirrors";
1043 dm_dirty_log_destroy(dl);
1044 return -EINVAL;
1045 }
1046
1047 argv++, argc--;
1048
1049 if (argc < nr_mirrors * 2) {
1050 ti->error = "Too few mirror arguments";
1051 dm_dirty_log_destroy(dl);
1052 return -EINVAL;
1053 }
1054
1055 ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl);
1056 if (!ms) {
1057 dm_dirty_log_destroy(dl);
1058 return -ENOMEM;
1059 }
1060
1061
1062 for (m = 0; m < nr_mirrors; m++) {
1063 r = get_mirror(ms, ti, m, argv);
1064 if (r) {
1065 free_context(ms, ti, m);
1066 return r;
1067 }
1068 argv += 2;
1069 argc -= 2;
1070 }
1071
1072 ti->private = ms;
1073
1074 r = dm_set_target_max_io_len(ti, dm_rh_get_region_size(ms->rh));
1075 if (r)
1076 goto err_free_context;
1077
1078 ti->num_flush_bios = 1;
1079 ti->num_discard_bios = 1;
1080 ti->per_bio_data_size = sizeof(struct dm_raid1_bio_record);
1081 ti->discard_zeroes_data_unsupported = true;
1082
1083 ms->kmirrord_wq = alloc_workqueue("kmirrord", WQ_MEM_RECLAIM, 0);
1084 if (!ms->kmirrord_wq) {
1085 DMERR("couldn't start kmirrord");
1086 r = -ENOMEM;
1087 goto err_free_context;
1088 }
1089 INIT_WORK(&ms->kmirrord_work, do_mirror);
1090 init_timer(&ms->timer);
1091 ms->timer_pending = 0;
1092 INIT_WORK(&ms->trigger_event, trigger_event);
1093
1094 r = parse_features(ms, argc, argv, &args_used);
1095 if (r)
1096 goto err_destroy_wq;
1097
1098 argv += args_used;
1099 argc -= args_used;
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110 if (argc) {
1111 ti->error = "Too many mirror arguments";
1112 r = -EINVAL;
1113 goto err_destroy_wq;
1114 }
1115
1116 ms->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle);
1117 if (IS_ERR(ms->kcopyd_client)) {
1118 r = PTR_ERR(ms->kcopyd_client);
1119 goto err_destroy_wq;
1120 }
1121
1122 wakeup_mirrord(ms);
1123 return 0;
1124
1125err_destroy_wq:
1126 destroy_workqueue(ms->kmirrord_wq);
1127err_free_context:
1128 free_context(ms, ti, ms->nr_mirrors);
1129 return r;
1130}
1131
1132static void mirror_dtr(struct dm_target *ti)
1133{
1134 struct mirror_set *ms = (struct mirror_set *) ti->private;
1135
1136 del_timer_sync(&ms->timer);
1137 flush_workqueue(ms->kmirrord_wq);
1138 flush_work(&ms->trigger_event);
1139 dm_kcopyd_client_destroy(ms->kcopyd_client);
1140 destroy_workqueue(ms->kmirrord_wq);
1141 free_context(ms, ti, ms->nr_mirrors);
1142}
1143
1144
1145
1146
1147static int mirror_map(struct dm_target *ti, struct bio *bio)
1148{
1149 int r, rw = bio_rw(bio);
1150 struct mirror *m;
1151 struct mirror_set *ms = ti->private;
1152 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
1153 struct dm_raid1_bio_record *bio_record =
1154 dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
1155
1156 bio_record->details.bi_bdev = NULL;
1157
1158 if (rw == WRITE) {
1159
1160 bio_record->write_region = dm_rh_bio_to_region(ms->rh, bio);
1161 queue_bio(ms, bio, rw);
1162 return DM_MAPIO_SUBMITTED;
1163 }
1164
1165 r = log->type->in_sync(log, dm_rh_bio_to_region(ms->rh, bio), 0);
1166 if (r < 0 && r != -EWOULDBLOCK)
1167 return r;
1168
1169
1170
1171
1172 if (!r || (r == -EWOULDBLOCK)) {
1173 if (rw == READA)
1174 return -EWOULDBLOCK;
1175
1176 queue_bio(ms, bio, rw);
1177 return DM_MAPIO_SUBMITTED;
1178 }
1179
1180
1181
1182
1183
1184 m = choose_mirror(ms, bio->bi_sector);
1185 if (unlikely(!m))
1186 return -EIO;
1187
1188 dm_bio_record(&bio_record->details, bio);
1189 bio_record->m = m;
1190
1191 map_bio(m, bio);
1192
1193 return DM_MAPIO_REMAPPED;
1194}
1195
1196static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error)
1197{
1198 int rw = bio_rw(bio);
1199 struct mirror_set *ms = (struct mirror_set *) ti->private;
1200 struct mirror *m = NULL;
1201 struct dm_bio_details *bd = NULL;
1202 struct dm_raid1_bio_record *bio_record =
1203 dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
1204
1205
1206
1207
1208 if (rw == WRITE) {
1209 if (!(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD)))
1210 dm_rh_dec(ms->rh, bio_record->write_region);
1211 return error;
1212 }
1213
1214 if (error == -EOPNOTSUPP)
1215 goto out;
1216
1217 if ((error == -EWOULDBLOCK) && (bio->bi_rw & REQ_RAHEAD))
1218 goto out;
1219
1220 if (unlikely(error)) {
1221 if (!bio_record->details.bi_bdev) {
1222
1223
1224
1225
1226
1227 DMERR_LIMIT("Mirror read failed.");
1228 return -EIO;
1229 }
1230
1231 m = bio_record->m;
1232
1233 DMERR("Mirror read failed from %s. Trying alternative device.",
1234 m->dev->name);
1235
1236 fail_mirror(m, DM_RAID1_READ_ERROR);
1237
1238
1239
1240
1241
1242 if (default_ok(m) || mirror_available(ms, bio)) {
1243 bd = &bio_record->details;
1244
1245 dm_bio_restore(bd, bio);
1246 bio_record->details.bi_bdev = NULL;
1247 queue_bio(ms, bio, rw);
1248 return DM_ENDIO_INCOMPLETE;
1249 }
1250 DMERR("All replicated volumes dead, failing I/O");
1251 }
1252
1253out:
1254 bio_record->details.bi_bdev = NULL;
1255
1256 return error;
1257}
1258
1259static void mirror_presuspend(struct dm_target *ti)
1260{
1261 struct mirror_set *ms = (struct mirror_set *) ti->private;
1262 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
1263
1264 struct bio_list holds;
1265 struct bio *bio;
1266
1267 atomic_set(&ms->suspend, 1);
1268
1269
1270
1271
1272
1273
1274
1275 spin_lock_irq(&ms->lock);
1276 holds = ms->holds;
1277 bio_list_init(&ms->holds);
1278 spin_unlock_irq(&ms->lock);
1279
1280 while ((bio = bio_list_pop(&holds)))
1281 hold_bio(ms, bio);
1282
1283
1284
1285
1286
1287 dm_rh_stop_recovery(ms->rh);
1288
1289 wait_event(_kmirrord_recovery_stopped,
1290 !dm_rh_recovery_in_flight(ms->rh));
1291
1292 if (log->type->presuspend && log->type->presuspend(log))
1293
1294 DMWARN("log presuspend failed");
1295
1296
1297
1298
1299
1300
1301
1302 flush_workqueue(ms->kmirrord_wq);
1303}
1304
1305static void mirror_postsuspend(struct dm_target *ti)
1306{
1307 struct mirror_set *ms = ti->private;
1308 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
1309
1310 if (log->type->postsuspend && log->type->postsuspend(log))
1311
1312 DMWARN("log postsuspend failed");
1313}
1314
1315static void mirror_resume(struct dm_target *ti)
1316{
1317 struct mirror_set *ms = ti->private;
1318 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
1319
1320 atomic_set(&ms->suspend, 0);
1321 if (log->type->resume && log->type->resume(log))
1322
1323 DMWARN("log resume failed");
1324 dm_rh_start_recovery(ms->rh);
1325}
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340static char device_status_char(struct mirror *m)
1341{
1342 if (!atomic_read(&(m->error_count)))
1343 return 'A';
1344
1345 return (test_bit(DM_RAID1_FLUSH_ERROR, &(m->error_type))) ? 'F' :
1346 (test_bit(DM_RAID1_WRITE_ERROR, &(m->error_type))) ? 'D' :
1347 (test_bit(DM_RAID1_SYNC_ERROR, &(m->error_type))) ? 'S' :
1348 (test_bit(DM_RAID1_READ_ERROR, &(m->error_type))) ? 'R' : 'U';
1349}
1350
1351
1352static void mirror_status(struct dm_target *ti, status_type_t type,
1353 unsigned status_flags, char *result, unsigned maxlen)
1354{
1355 unsigned int m, sz = 0;
1356 struct mirror_set *ms = (struct mirror_set *) ti->private;
1357 struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
1358 char buffer[ms->nr_mirrors + 1];
1359
1360 switch (type) {
1361 case STATUSTYPE_INFO:
1362 DMEMIT("%d ", ms->nr_mirrors);
1363 for (m = 0; m < ms->nr_mirrors; m++) {
1364 DMEMIT("%s ", ms->mirror[m].dev->name);
1365 buffer[m] = device_status_char(&(ms->mirror[m]));
1366 }
1367 buffer[m] = '\0';
1368
1369 DMEMIT("%llu/%llu 1 %s ",
1370 (unsigned long long)log->type->get_sync_count(log),
1371 (unsigned long long)ms->nr_regions, buffer);
1372
1373 sz += log->type->status(log, type, result+sz, maxlen-sz);
1374
1375 break;
1376
1377 case STATUSTYPE_TABLE:
1378 sz = log->type->status(log, type, result, maxlen);
1379
1380 DMEMIT("%d", ms->nr_mirrors);
1381 for (m = 0; m < ms->nr_mirrors; m++)
1382 DMEMIT(" %s %llu", ms->mirror[m].dev->name,
1383 (unsigned long long)ms->mirror[m].offset);
1384
1385 if (ms->features & DM_RAID1_HANDLE_ERRORS)
1386 DMEMIT(" 1 handle_errors");
1387 }
1388}
1389
1390static int mirror_iterate_devices(struct dm_target *ti,
1391 iterate_devices_callout_fn fn, void *data)
1392{
1393 struct mirror_set *ms = ti->private;
1394 int ret = 0;
1395 unsigned i;
1396
1397 for (i = 0; !ret && i < ms->nr_mirrors; i++)
1398 ret = fn(ti, ms->mirror[i].dev,
1399 ms->mirror[i].offset, ti->len, data);
1400
1401 return ret;
1402}
1403
1404static struct target_type mirror_target = {
1405 .name = "mirror",
1406 .version = {1, 13, 2},
1407 .module = THIS_MODULE,
1408 .ctr = mirror_ctr,
1409 .dtr = mirror_dtr,
1410 .map = mirror_map,
1411 .end_io = mirror_end_io,
1412 .presuspend = mirror_presuspend,
1413 .postsuspend = mirror_postsuspend,
1414 .resume = mirror_resume,
1415 .status = mirror_status,
1416 .iterate_devices = mirror_iterate_devices,
1417};
1418
1419static int __init dm_mirror_init(void)
1420{
1421 int r;
1422
1423 r = dm_register_target(&mirror_target);
1424 if (r < 0) {
1425 DMERR("Failed to register mirror target");
1426 goto bad_target;
1427 }
1428
1429 return 0;
1430
1431bad_target:
1432 return r;
1433}
1434
1435static void __exit dm_mirror_exit(void)
1436{
1437 dm_unregister_target(&mirror_target);
1438}
1439
1440
1441module_init(dm_mirror_init);
1442module_exit(dm_mirror_exit);
1443
1444MODULE_DESCRIPTION(DM_NAME " mirror target");
1445MODULE_AUTHOR("Joe Thornber");
1446MODULE_LICENSE("GPL");
1447