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 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 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 = bitmap_prepare_for_write,
112 .check = 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 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 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 ll->tm = tm;
194
195 ll->bitmap_info.tm = tm;
196 ll->bitmap_info.levels = 1;
197
198
199
200
201
202
203 ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
204 ll->bitmap_info.value_type.inc = NULL;
205 ll->bitmap_info.value_type.dec = NULL;
206 ll->bitmap_info.value_type.equal = NULL;
207
208 ll->ref_count_info.tm = tm;
209 ll->ref_count_info.levels = 1;
210 ll->ref_count_info.value_type.size = sizeof(uint32_t);
211 ll->ref_count_info.value_type.inc = NULL;
212 ll->ref_count_info.value_type.dec = NULL;
213 ll->ref_count_info.value_type.equal = NULL;
214
215 ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
216
217 if (ll->block_size > (1 << 30)) {
218 DMERR("block size too big to hold bitmaps");
219 return -EINVAL;
220 }
221
222 ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
223 ENTRIES_PER_BYTE;
224 ll->nr_blocks = 0;
225 ll->bitmap_root = 0;
226 ll->ref_count_root = 0;
227 ll->bitmap_index_changed = false;
228
229 return 0;
230}
231
232int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
233{
234 int r;
235 dm_block_t i, nr_blocks, nr_indexes;
236 unsigned old_blocks, blocks;
237
238 nr_blocks = ll->nr_blocks + extra_blocks;
239 old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
240 blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
241
242 nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
243 if (nr_indexes > ll->max_entries(ll)) {
244 DMERR("space map too large");
245 return -EINVAL;
246 }
247
248
249
250
251 ll->nr_blocks = nr_blocks;
252 for (i = old_blocks; i < blocks; i++) {
253 struct dm_block *b;
254 struct disk_index_entry idx;
255
256 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
257 if (r < 0)
258 return r;
259
260 idx.blocknr = cpu_to_le64(dm_block_location(b));
261
262 r = dm_tm_unlock(ll->tm, b);
263 if (r < 0)
264 return r;
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 return dm_tm_unlock(ll->tm, blk);
297}
298
299static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
300 uint32_t *result)
301{
302 __le32 le_rc;
303 int r;
304
305 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
306 if (r < 0)
307 return r;
308
309 *result = le32_to_cpu(le_rc);
310
311 return r;
312}
313
314int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
315{
316 int r = sm_ll_lookup_bitmap(ll, b, result);
317
318 if (r)
319 return r;
320
321 if (*result != 3)
322 return r;
323
324 return sm_ll_lookup_big_ref_count(ll, b, result);
325}
326
327int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
328 dm_block_t end, dm_block_t *result)
329{
330 int r;
331 struct disk_index_entry ie_disk;
332 dm_block_t i, index_begin = begin;
333 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
334
335
336
337
338 begin = do_div(index_begin, ll->entries_per_block);
339 end = do_div(end, ll->entries_per_block);
340
341 for (i = index_begin; i < index_end; i++, begin = 0) {
342 struct dm_block *blk;
343 unsigned position;
344 uint32_t bit_end;
345
346 r = ll->load_ie(ll, i, &ie_disk);
347 if (r < 0)
348 return r;
349
350 if (le32_to_cpu(ie_disk.nr_free) == 0)
351 continue;
352
353 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
354 &dm_sm_bitmap_validator, &blk);
355 if (r < 0)
356 return r;
357
358 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
359
360 r = sm_find_free(dm_bitmap_data(blk),
361 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
362 bit_end, &position);
363 if (r == -ENOSPC) {
364
365
366
367
368 dm_tm_unlock(ll->tm, blk);
369 continue;
370
371 } else if (r < 0) {
372 dm_tm_unlock(ll->tm, blk);
373 return r;
374 }
375
376 r = dm_tm_unlock(ll->tm, blk);
377 if (r < 0)
378 return r;
379
380 *result = i * ll->entries_per_block + (dm_block_t) position;
381 return 0;
382 }
383
384 return -ENOSPC;
385}
386
387static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
388 int (*mutator)(void *context, uint32_t old, uint32_t *new),
389 void *context, enum allocation_event *ev)
390{
391 int r;
392 uint32_t bit, old, ref_count;
393 struct dm_block *nb;
394 dm_block_t index = b;
395 struct disk_index_entry ie_disk;
396 void *bm_le;
397 int inc;
398
399 bit = do_div(index, ll->entries_per_block);
400 r = ll->load_ie(ll, index, &ie_disk);
401 if (r < 0)
402 return r;
403
404 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
405 &dm_sm_bitmap_validator, &nb, &inc);
406 if (r < 0) {
407 DMERR("dm_tm_shadow_block() failed");
408 return r;
409 }
410 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
411
412 bm_le = dm_bitmap_data(nb);
413 old = sm_lookup_bitmap(bm_le, bit);
414
415 if (old > 2) {
416 r = sm_ll_lookup_big_ref_count(ll, b, &old);
417 if (r < 0) {
418 dm_tm_unlock(ll->tm, nb);
419 return r;
420 }
421 }
422
423 r = mutator(context, old, &ref_count);
424 if (r) {
425 dm_tm_unlock(ll->tm, nb);
426 return r;
427 }
428
429 if (ref_count <= 2) {
430 sm_set_bitmap(bm_le, bit, ref_count);
431
432 r = dm_tm_unlock(ll->tm, nb);
433 if (r < 0)
434 return r;
435
436 if (old > 2) {
437 r = dm_btree_remove(&ll->ref_count_info,
438 ll->ref_count_root,
439 &b, &ll->ref_count_root);
440 if (r)
441 return r;
442 }
443
444 } else {
445 __le32 le_rc = cpu_to_le32(ref_count);
446
447 sm_set_bitmap(bm_le, bit, 3);
448 r = dm_tm_unlock(ll->tm, nb);
449 if (r < 0)
450 return r;
451
452 __dm_bless_for_disk(&le_rc);
453 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
454 &b, &le_rc, &ll->ref_count_root);
455 if (r < 0) {
456 DMERR("ref count insert failed");
457 return r;
458 }
459 }
460
461 if (ref_count && !old) {
462 *ev = SM_ALLOC;
463 ll->nr_allocated++;
464 le32_add_cpu(&ie_disk.nr_free, -1);
465 if (le32_to_cpu(ie_disk.none_free_before) == bit)
466 ie_disk.none_free_before = cpu_to_le32(bit + 1);
467
468 } else if (old && !ref_count) {
469 *ev = SM_FREE;
470 ll->nr_allocated--;
471 le32_add_cpu(&ie_disk.nr_free, 1);
472 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
473 }
474
475 return ll->save_ie(ll, index, &ie_disk);
476}
477
478static int set_ref_count(void *context, uint32_t old, uint32_t *new)
479{
480 *new = *((uint32_t *) context);
481 return 0;
482}
483
484int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
485 uint32_t ref_count, enum allocation_event *ev)
486{
487 return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
488}
489
490static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
491{
492 *new = old + 1;
493 return 0;
494}
495
496int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
497{
498 return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
499}
500
501static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
502{
503 if (!old) {
504 DMERR_LIMIT("unable to decrement a reference count below 0");
505 return -EINVAL;
506 }
507
508 *new = old - 1;
509 return 0;
510}
511
512int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
513{
514 return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
515}
516
517int sm_ll_commit(struct ll_disk *ll)
518{
519 int r = 0;
520
521 if (ll->bitmap_index_changed) {
522 r = ll->commit(ll);
523 if (!r)
524 ll->bitmap_index_changed = false;
525 }
526
527 return r;
528}
529
530
531
532static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
533 struct disk_index_entry *ie)
534{
535 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
536 return 0;
537}
538
539static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
540 struct disk_index_entry *ie)
541{
542 ll->bitmap_index_changed = true;
543 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
544 return 0;
545}
546
547static int metadata_ll_init_index(struct ll_disk *ll)
548{
549 int r;
550 struct dm_block *b;
551
552 r = dm_tm_new_block(ll->tm, &index_validator, &b);
553 if (r < 0)
554 return r;
555
556 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
557 ll->bitmap_root = dm_block_location(b);
558
559 return dm_tm_unlock(ll->tm, b);
560}
561
562static int metadata_ll_open(struct ll_disk *ll)
563{
564 int r;
565 struct dm_block *block;
566
567 r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
568 &index_validator, &block);
569 if (r)
570 return r;
571
572 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
573 return dm_tm_unlock(ll->tm, block);
574}
575
576static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
577{
578 return MAX_METADATA_BITMAPS;
579}
580
581static int metadata_ll_commit(struct ll_disk *ll)
582{
583 int r, inc;
584 struct dm_block *b;
585
586 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
587 if (r)
588 return r;
589
590 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
591 ll->bitmap_root = dm_block_location(b);
592
593 return dm_tm_unlock(ll->tm, b);
594}
595
596int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
597{
598 int r;
599
600 r = sm_ll_init(ll, tm);
601 if (r < 0)
602 return r;
603
604 ll->load_ie = metadata_ll_load_ie;
605 ll->save_ie = metadata_ll_save_ie;
606 ll->init_index = metadata_ll_init_index;
607 ll->open_index = metadata_ll_open;
608 ll->max_entries = metadata_ll_max_entries;
609 ll->commit = metadata_ll_commit;
610
611 ll->nr_blocks = 0;
612 ll->nr_allocated = 0;
613
614 r = ll->init_index(ll);
615 if (r < 0)
616 return r;
617
618 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
619 if (r < 0)
620 return r;
621
622 return 0;
623}
624
625int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
626 void *root_le, size_t len)
627{
628 int r;
629 struct disk_sm_root *smr = root_le;
630
631 if (len < sizeof(struct disk_sm_root)) {
632 DMERR("sm_metadata root too small");
633 return -ENOMEM;
634 }
635
636 r = sm_ll_init(ll, tm);
637 if (r < 0)
638 return r;
639
640 ll->load_ie = metadata_ll_load_ie;
641 ll->save_ie = metadata_ll_save_ie;
642 ll->init_index = metadata_ll_init_index;
643 ll->open_index = metadata_ll_open;
644 ll->max_entries = metadata_ll_max_entries;
645 ll->commit = metadata_ll_commit;
646
647 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
648 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
649 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
650 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
651
652 return ll->open_index(ll);
653}
654
655
656
657static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
658 struct disk_index_entry *ie)
659{
660 return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
661}
662
663static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
664 struct disk_index_entry *ie)
665{
666 __dm_bless_for_disk(ie);
667 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
668 &index, ie, &ll->bitmap_root);
669}
670
671static int disk_ll_init_index(struct ll_disk *ll)
672{
673 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
674}
675
676static int disk_ll_open(struct ll_disk *ll)
677{
678
679 return 0;
680}
681
682static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
683{
684 return -1ULL;
685}
686
687static int disk_ll_commit(struct ll_disk *ll)
688{
689 return 0;
690}
691
692int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
693{
694 int r;
695
696 r = sm_ll_init(ll, tm);
697 if (r < 0)
698 return r;
699
700 ll->load_ie = disk_ll_load_ie;
701 ll->save_ie = disk_ll_save_ie;
702 ll->init_index = disk_ll_init_index;
703 ll->open_index = disk_ll_open;
704 ll->max_entries = disk_ll_max_entries;
705 ll->commit = disk_ll_commit;
706
707 ll->nr_blocks = 0;
708 ll->nr_allocated = 0;
709
710 r = ll->init_index(ll);
711 if (r < 0)
712 return r;
713
714 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
715 if (r < 0)
716 return r;
717
718 return 0;
719}
720
721int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
722 void *root_le, size_t len)
723{
724 int r;
725 struct disk_sm_root *smr = root_le;
726
727 if (len < sizeof(struct disk_sm_root)) {
728 DMERR("sm_metadata root too small");
729 return -ENOMEM;
730 }
731
732 r = sm_ll_init(ll, tm);
733 if (r < 0)
734 return r;
735
736 ll->load_ie = disk_ll_load_ie;
737 ll->save_ie = disk_ll_save_ie;
738 ll->init_index = disk_ll_init_index;
739 ll->open_index = disk_ll_open;
740 ll->max_entries = disk_ll_max_entries;
741 ll->commit = disk_ll_commit;
742
743 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
744 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
745 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
746 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
747
748 return ll->open_index(ll);
749}
750
751
752
