1
2
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5
6
7#include "dm-space-map-common.h"
8#include "dm-transaction-manager.h"
9
10#include <linux/bitops.h>
11#include <linux/device-mapper.h>
12
13#define DM_MSG_PREFIX "space map common"
14
15
16
17
18
19
20#define INDEX_CSUM_XOR 160478
21
22static void index_prepare_for_write(struct dm_block_validator *v,
23 struct dm_block *b,
24 size_t block_size)
25{
26 struct disk_metadata_index *mi_le = dm_block_data(b);
27
28 mi_le->blocknr = cpu_to_le64(dm_block_location(b));
29 mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
30 block_size - sizeof(__le32),
31 INDEX_CSUM_XOR));
32}
33
34static int index_check(struct dm_block_validator *v,
35 struct dm_block *b,
36 size_t block_size)
37{
38 struct disk_metadata_index *mi_le = dm_block_data(b);
39 __le32 csum_disk;
40
41 if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
42 DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
43 le64_to_cpu(mi_le->blocknr), dm_block_location(b));
44 return -ENOTBLK;
45 }
46
47 csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
48 block_size - sizeof(__le32),
49 INDEX_CSUM_XOR));
50 if (csum_disk != mi_le->csum) {
51 DMERR_LIMIT("index_check failed: csum %u != wanted %u",
52 le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
53 return -EILSEQ;
54 }
55
56 return 0;
57}
58
59static struct dm_block_validator index_validator = {
60 .name = "index",
61 .prepare_for_write = index_prepare_for_write,
62 .check = index_check
63};
64
65
66
67
68
69
70#define BITMAP_CSUM_XOR 240779
71
72static void dm_bitmap_prepare_for_write(struct dm_block_validator *v,
73 struct dm_block *b,
74 size_t block_size)
75{
76 struct disk_bitmap_header *disk_header = dm_block_data(b);
77
78 disk_header->blocknr = cpu_to_le64(dm_block_location(b));
79 disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
80 block_size - sizeof(__le32),
81 BITMAP_CSUM_XOR));
82}
83
84static int dm_bitmap_check(struct dm_block_validator *v,
85 struct dm_block *b,
86 size_t block_size)
87{
88 struct disk_bitmap_header *disk_header = dm_block_data(b);
89 __le32 csum_disk;
90
91 if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
92 DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
93 le64_to_cpu(disk_header->blocknr), dm_block_location(b));
94 return -ENOTBLK;
95 }
96
97 csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
98 block_size - sizeof(__le32),
99 BITMAP_CSUM_XOR));
100 if (csum_disk != disk_header->csum) {
101 DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
102 le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
103 return -EILSEQ;
104 }
105
106 return 0;
107}
108
109static struct dm_block_validator dm_sm_bitmap_validator = {
110 .name = "sm_bitmap",
111 .prepare_for_write = dm_bitmap_prepare_for_write,
112 .check = dm_bitmap_check,
113};
114
115
116
117#define ENTRIES_PER_WORD 32
118#define ENTRIES_SHIFT 5
119
120static void *dm_bitmap_data(struct dm_block *b)
121{
122 return dm_block_data(b) + sizeof(struct disk_bitmap_header);
123}
124
125#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
126
127static unsigned dm_bitmap_word_used(void *addr, unsigned b)
128{
129 __le64 *words_le = addr;
130 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
131
132 uint64_t bits = le64_to_cpu(*w_le);
133 uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
134
135 return !(~bits & mask);
136}
137
138static unsigned sm_lookup_bitmap(void *addr, unsigned b)
139{
140 __le64 *words_le = addr;
141 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
142 unsigned hi, lo;
143
144 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
145 hi = !!test_bit_le(b, (void *) w_le);
146 lo = !!test_bit_le(b + 1, (void *) w_le);
147 return (hi << 1) | lo;
148}
149
150static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
151{
152 __le64 *words_le = addr;
153 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
154
155 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
156
157 if (val & 2)
158 __set_bit_le(b, (void *) w_le);
159 else
160 __clear_bit_le(b, (void *) w_le);
161
162 if (val & 1)
163 __set_bit_le(b + 1, (void *) w_le);
164 else
165 __clear_bit_le(b + 1, (void *) w_le);
166}
167
168static int sm_find_free(void *addr, unsigned begin, unsigned end,
169 unsigned *result)
170{
171 while (begin < end) {
172 if (!(begin & (ENTRIES_PER_WORD - 1)) &&
173 dm_bitmap_word_used(addr, begin)) {
174 begin += ENTRIES_PER_WORD;
175 continue;
176 }
177
178 if (!sm_lookup_bitmap(addr, begin)) {
179 *result = begin;
180 return 0;
181 }
182
183 begin++;
184 }
185
186 return -ENOSPC;
187}
188
189
190
191static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
192{
193 memset(ll, 0, sizeof(struct ll_disk));
194
195 ll->tm = tm;
196
197 ll->bitmap_info.tm = tm;
198 ll->bitmap_info.levels = 1;
199
200
201
202
203
204
205 ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
206 ll->bitmap_info.value_type.inc = NULL;
207 ll->bitmap_info.value_type.dec = NULL;
208 ll->bitmap_info.value_type.equal = NULL;
209
210 ll->ref_count_info.tm = tm;
211 ll->ref_count_info.levels = 1;
212 ll->ref_count_info.value_type.size = sizeof(uint32_t);
213 ll->ref_count_info.value_type.inc = NULL;
214 ll->ref_count_info.value_type.dec = NULL;
215 ll->ref_count_info.value_type.equal = NULL;
216
217 ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
218
219 if (ll->block_size > (1 << 30)) {
220 DMERR("block size too big to hold bitmaps");
221 return -EINVAL;
222 }
223
224 ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
225 ENTRIES_PER_BYTE;
226 ll->nr_blocks = 0;
227 ll->bitmap_root = 0;
228 ll->ref_count_root = 0;
229 ll->bitmap_index_changed = false;
230
231 return 0;
232}
233
234int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
235{
236 int r;
237 dm_block_t i, nr_blocks, nr_indexes;
238 unsigned old_blocks, blocks;
239
240 nr_blocks = ll->nr_blocks + extra_blocks;
241 old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
242 blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
243
244 nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
245 if (nr_indexes > ll->max_entries(ll)) {
246 DMERR("space map too large");
247 return -EINVAL;
248 }
249
250
251
252
253 ll->nr_blocks = nr_blocks;
254 for (i = old_blocks; i < blocks; i++) {
255 struct dm_block *b;
256 struct disk_index_entry idx;
257
258 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
259 if (r < 0)
260 return r;
261
262 idx.blocknr = cpu_to_le64(dm_block_location(b));
263
264 dm_tm_unlock(ll->tm, b);
265
266 idx.nr_free = cpu_to_le32(ll->entries_per_block);
267 idx.none_free_before = 0;
268
269 r = ll->save_ie(ll, i, &idx);
270 if (r < 0)
271 return r;
272 }
273
274 return 0;
275}
276
277int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
278{
279 int r;
280 dm_block_t index = b;
281 struct disk_index_entry ie_disk;
282 struct dm_block *blk;
283
284 b = do_div(index, ll->entries_per_block);
285 r = ll->load_ie(ll, index, &ie_disk);
286 if (r < 0)
287 return r;
288
289 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
290 &dm_sm_bitmap_validator, &blk);
291 if (r < 0)
292 return r;
293
294 *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
295
296 dm_tm_unlock(ll->tm, blk);
297
298 return 0;
299}
300
301static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
302 uint32_t *result)
303{
304 __le32 le_rc;
305 int r;
306
307 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
308 if (r < 0)
309 return r;
310
311 *result = le32_to_cpu(le_rc);
312
313 return r;
314}
315
316int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
317{
318 int r = sm_ll_lookup_bitmap(ll, b, result);
319
320 if (r)
321 return r;
322
323 if (*result != 3)
324 return r;
325
326 return sm_ll_lookup_big_ref_count(ll, b, result);
327}
328
329int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
330 dm_block_t end, dm_block_t *result)
331{
332 int r;
333 struct disk_index_entry ie_disk;
334 dm_block_t i, index_begin = begin;
335 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
336
337
338
339
340 begin = do_div(index_begin, ll->entries_per_block);
341 end = do_div(end, ll->entries_per_block);
342
343 for (i = index_begin; i < index_end; i++, begin = 0) {
344 struct dm_block *blk;
345 unsigned position;
346 uint32_t bit_end;
347
348 r = ll->load_ie(ll, i, &ie_disk);
349 if (r < 0)
350 return r;
351
352 if (le32_to_cpu(ie_disk.nr_free) == 0)
353 continue;
354
355 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
356 &dm_sm_bitmap_validator, &blk);
357 if (r < 0)
358 return r;
359
360 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
361
362 r = sm_find_free(dm_bitmap_data(blk),
363 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
364 bit_end, &position);
365 if (r == -ENOSPC) {
366
367
368
369
370 dm_tm_unlock(ll->tm, blk);
371 continue;
372 }
373
374 dm_tm_unlock(ll->tm, blk);
375
376 *result = i * ll->entries_per_block + (dm_block_t) position;
377 return 0;
378 }
379
380 return -ENOSPC;
381}
382
383int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
384 dm_block_t begin, dm_block_t end, dm_block_t *b)
385{
386 int r;
387 uint32_t count;
388
389 do {
390 r = sm_ll_find_free_block(new_ll, begin, new_ll->nr_blocks, b);
391 if (r)
392 break;
393
394
395 if (*b >= old_ll->nr_blocks)
396 count = 0;
397 else {
398 r = sm_ll_lookup(old_ll, *b, &count);
399 if (r)
400 break;
401
402 if (count)
403 begin = *b + 1;
404 }
405 } while (count);
406
407 return r;
408}
409
410static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
411 int (*mutator)(void *context, uint32_t old, uint32_t *new),
412 void *context, enum allocation_event *ev)
413{
414 int r;
415 uint32_t bit, old, ref_count;
416 struct dm_block *nb;
417 dm_block_t index = b;
418 struct disk_index_entry ie_disk;
419 void *bm_le;
420 int inc;
421
422 bit = do_div(index, ll->entries_per_block);
423 r = ll->load_ie(ll, index, &ie_disk);
424 if (r < 0)
425 return r;
426
427 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
428 &dm_sm_bitmap_validator, &nb, &inc);
429 if (r < 0) {
430 DMERR("dm_tm_shadow_block() failed");
431 return r;
432 }
433 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
434
435 bm_le = dm_bitmap_data(nb);
436 old = sm_lookup_bitmap(bm_le, bit);
437
438 if (old > 2) {
439 r = sm_ll_lookup_big_ref_count(ll, b, &old);
440 if (r < 0) {
441 dm_tm_unlock(ll->tm, nb);
442 return r;
443 }
444 }
445
446 r = mutator(context, old, &ref_count);
447 if (r) {
448 dm_tm_unlock(ll->tm, nb);
449 return r;
450 }
451
452 if (ref_count <= 2) {
453 sm_set_bitmap(bm_le, bit, ref_count);
454
455 dm_tm_unlock(ll->tm, nb);
456
457 if (old > 2) {
458 r = dm_btree_remove(&ll->ref_count_info,
459 ll->ref_count_root,
460 &b, &ll->ref_count_root);
461 if (r)
462 return r;
463 }
464
465 } else {
466 __le32 le_rc = cpu_to_le32(ref_count);
467
468 sm_set_bitmap(bm_le, bit, 3);
469 dm_tm_unlock(ll->tm, nb);
470
471 __dm_bless_for_disk(&le_rc);
472 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
473 &b, &le_rc, &ll->ref_count_root);
474 if (r < 0) {
475 DMERR("ref count insert failed");
476 return r;
477 }
478 }
479
480 if (ref_count && !old) {
481 *ev = SM_ALLOC;
482 ll->nr_allocated++;
483 le32_add_cpu(&ie_disk.nr_free, -1);
484 if (le32_to_cpu(ie_disk.none_free_before) == bit)
485 ie_disk.none_free_before = cpu_to_le32(bit + 1);
486
487 } else if (old && !ref_count) {
488 *ev = SM_FREE;
489 ll->nr_allocated--;
490 le32_add_cpu(&ie_disk.nr_free, 1);
491 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
492 } else
493 *ev = SM_NONE;
494
495 return ll->save_ie(ll, index, &ie_disk);
496}
497
498static int set_ref_count(void *context, uint32_t old, uint32_t *new)
499{
500 *new = *((uint32_t *) context);
501 return 0;
502}
503
504int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
505 uint32_t ref_count, enum allocation_event *ev)
506{
507 return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
508}
509
510static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
511{
512 *new = old + 1;
513 return 0;
514}
515
516int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
517{
518 return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
519}
520
521static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
522{
523 if (!old) {
524 DMERR_LIMIT("unable to decrement a reference count below 0");
525 return -EINVAL;
526 }
527
528 *new = old - 1;
529 return 0;
530}
531
532int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
533{
534 return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
535}
536
537int sm_ll_commit(struct ll_disk *ll)
538{
539 int r = 0;
540
541 if (ll->bitmap_index_changed) {
542 r = ll->commit(ll);
543 if (!r)
544 ll->bitmap_index_changed = false;
545 }
546
547 return r;
548}
549
550
551
552static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
553 struct disk_index_entry *ie)
554{
555 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
556 return 0;
557}
558
559static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
560 struct disk_index_entry *ie)
561{
562 ll->bitmap_index_changed = true;
563 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
564 return 0;
565}
566
567static int metadata_ll_init_index(struct ll_disk *ll)
568{
569 int r;
570 struct dm_block *b;
571
572 r = dm_tm_new_block(ll->tm, &index_validator, &b);
573 if (r < 0)
574 return r;
575
576 ll->bitmap_root = dm_block_location(b);
577
578 dm_tm_unlock(ll->tm, b);
579
580 return 0;
581}
582
583static int metadata_ll_open(struct ll_disk *ll)
584{
585 int r;
586 struct dm_block *block;
587
588 r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
589 &index_validator, &block);
590 if (r)
591 return r;
592
593 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
594 dm_tm_unlock(ll->tm, block);
595
596 return 0;
597}
598
599static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
600{
601 return MAX_METADATA_BITMAPS;
602}
603
604static int metadata_ll_commit(struct ll_disk *ll)
605{
606 int r, inc;
607 struct dm_block *b;
608
609 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
610 if (r)
611 return r;
612
613 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
614 ll->bitmap_root = dm_block_location(b);
615
616 dm_tm_unlock(ll->tm, b);
617
618 return 0;
619}
620
621int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
622{
623 int r;
624
625 r = sm_ll_init(ll, tm);
626 if (r < 0)
627 return r;
628
629 ll->load_ie = metadata_ll_load_ie;
630 ll->save_ie = metadata_ll_save_ie;
631 ll->init_index = metadata_ll_init_index;
632 ll->open_index = metadata_ll_open;
633 ll->max_entries = metadata_ll_max_entries;
634 ll->commit = metadata_ll_commit;
635
636 ll->nr_blocks = 0;
637 ll->nr_allocated = 0;
638
639 r = ll->init_index(ll);
640 if (r < 0)
641 return r;
642
643 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
644 if (r < 0)
645 return r;
646
647 return 0;
648}
649
650int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
651 void *root_le, size_t len)
652{
653 int r;
654 struct disk_sm_root smr;
655
656 if (len < sizeof(struct disk_sm_root)) {
657 DMERR("sm_metadata root too small");
658 return -ENOMEM;
659 }
660
661
662
663
664
665 memcpy(&smr, root_le, sizeof(smr));
666
667 r = sm_ll_init(ll, tm);
668 if (r < 0)
669 return r;
670
671 ll->load_ie = metadata_ll_load_ie;
672 ll->save_ie = metadata_ll_save_ie;
673 ll->init_index = metadata_ll_init_index;
674 ll->open_index = metadata_ll_open;
675 ll->max_entries = metadata_ll_max_entries;
676 ll->commit = metadata_ll_commit;
677
678 ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
679 ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
680 ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
681 ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
682
683 return ll->open_index(ll);
684}
685
686
687
688static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
689 struct disk_index_entry *ie)
690{
691 return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
692}
693
694static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
695 struct disk_index_entry *ie)
696{
697 __dm_bless_for_disk(ie);
698 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
699 &index, ie, &ll->bitmap_root);
700}
701
702static int disk_ll_init_index(struct ll_disk *ll)
703{
704 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
705}
706
707static int disk_ll_open(struct ll_disk *ll)
708{
709
710 return 0;
711}
712
713static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
714{
715 return -1ULL;
716}
717
718static int disk_ll_commit(struct ll_disk *ll)
719{
720 return 0;
721}
722
723int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
724{
725 int r;
726
727 r = sm_ll_init(ll, tm);
728 if (r < 0)
729 return r;
730
731 ll->load_ie = disk_ll_load_ie;
732 ll->save_ie = disk_ll_save_ie;
733 ll->init_index = disk_ll_init_index;
734 ll->open_index = disk_ll_open;
735 ll->max_entries = disk_ll_max_entries;
736 ll->commit = disk_ll_commit;
737
738 ll->nr_blocks = 0;
739 ll->nr_allocated = 0;
740
741 r = ll->init_index(ll);
742 if (r < 0)
743 return r;
744
745 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
746 if (r < 0)
747 return r;
748
749 return 0;
750}
751
752int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
753 void *root_le, size_t len)
754{
755 int r;
756 struct disk_sm_root *smr = root_le;
757
758 if (len < sizeof(struct disk_sm_root)) {
759 DMERR("sm_metadata root too small");
760 return -ENOMEM;
761 }
762
763 r = sm_ll_init(ll, tm);
764 if (r < 0)
765 return r;
766
767 ll->load_ie = disk_ll_load_ie;
768 ll->save_ie = disk_ll_save_ie;
769 ll->init_index = disk_ll_init_index;
770 ll->open_index = disk_ll_open;
771 ll->max_entries = disk_ll_max_entries;
772 ll->commit = disk_ll_commit;
773
774 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
775 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
776 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
777 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
778
779 return ll->open_index(ll);
780}
781
782
783
