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1/*
2 * Copyright (C) 2011 Red Hat, Inc.
3 *
4 * This file is released under the GPL.
5 */
6
7#include "dm-space-map-common.h"
8#include "dm-transaction-manager.h"
9#include "dm-btree-internal.h"
10#include "dm-persistent-data-internal.h"
11
12#include <linux/bitops.h>
13#include <linux/device-mapper.h>
14
15#define DM_MSG_PREFIX "space map common"
16
17/*----------------------------------------------------------------*/
18
19/*
20 * Index validator.
21 */
22#define INDEX_CSUM_XOR 160478
23
24static void index_prepare_for_write(struct dm_block_validator *v,
25 struct dm_block *b,
26 size_t block_size)
27{
28 struct disk_metadata_index *mi_le = dm_block_data(b);
29
30 mi_le->blocknr = cpu_to_le64(dm_block_location(b));
31 mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
32 block_size - sizeof(__le32),
33 INDEX_CSUM_XOR));
34}
35
36static int index_check(struct dm_block_validator *v,
37 struct dm_block *b,
38 size_t block_size)
39{
40 struct disk_metadata_index *mi_le = dm_block_data(b);
41 __le32 csum_disk;
42
43 if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
44 DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
45 le64_to_cpu(mi_le->blocknr), dm_block_location(b));
46 return -ENOTBLK;
47 }
48
49 csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
50 block_size - sizeof(__le32),
51 INDEX_CSUM_XOR));
52 if (csum_disk != mi_le->csum) {
53 DMERR_LIMIT("index_check failed: csum %u != wanted %u",
54 le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
55 return -EILSEQ;
56 }
57
58 return 0;
59}
60
61static struct dm_block_validator index_validator = {
62 .name = "index",
63 .prepare_for_write = index_prepare_for_write,
64 .check = index_check
65};
66
67/*----------------------------------------------------------------*/
68
69/*
70 * Bitmap validator
71 */
72#define BITMAP_CSUM_XOR 240779
73
74static void dm_bitmap_prepare_for_write(struct dm_block_validator *v,
75 struct dm_block *b,
76 size_t block_size)
77{
78 struct disk_bitmap_header *disk_header = dm_block_data(b);
79
80 disk_header->blocknr = cpu_to_le64(dm_block_location(b));
81 disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
82 block_size - sizeof(__le32),
83 BITMAP_CSUM_XOR));
84}
85
86static int dm_bitmap_check(struct dm_block_validator *v,
87 struct dm_block *b,
88 size_t block_size)
89{
90 struct disk_bitmap_header *disk_header = dm_block_data(b);
91 __le32 csum_disk;
92
93 if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
94 DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
95 le64_to_cpu(disk_header->blocknr), dm_block_location(b));
96 return -ENOTBLK;
97 }
98
99 csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
100 block_size - sizeof(__le32),
101 BITMAP_CSUM_XOR));
102 if (csum_disk != disk_header->csum) {
103 DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
104 le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
105 return -EILSEQ;
106 }
107
108 return 0;
109}
110
111static struct dm_block_validator dm_sm_bitmap_validator = {
112 .name = "sm_bitmap",
113 .prepare_for_write = dm_bitmap_prepare_for_write,
114 .check = dm_bitmap_check,
115};
116
117/*----------------------------------------------------------------*/
118
119#define ENTRIES_PER_WORD 32
120#define ENTRIES_SHIFT 5
121
122static void *dm_bitmap_data(struct dm_block *b)
123{
124 return dm_block_data(b) + sizeof(struct disk_bitmap_header);
125}
126
127#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
128
129static unsigned dm_bitmap_word_used(void *addr, unsigned b)
130{
131 __le64 *words_le = addr;
132 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
133
134 uint64_t bits = le64_to_cpu(*w_le);
135 uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
136
137 return !(~bits & mask);
138}
139
140static unsigned sm_lookup_bitmap(void *addr, unsigned b)
141{
142 __le64 *words_le = addr;
143 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
144 unsigned hi, lo;
145
146 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
147 hi = !!test_bit_le(b, (void *) w_le);
148 lo = !!test_bit_le(b + 1, (void *) w_le);
149 return (hi << 1) | lo;
150}
151
152static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
153{
154 __le64 *words_le = addr;
155 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
156
157 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
158
159 if (val & 2)
160 __set_bit_le(b, (void *) w_le);
161 else
162 __clear_bit_le(b, (void *) w_le);
163
164 if (val & 1)
165 __set_bit_le(b + 1, (void *) w_le);
166 else
167 __clear_bit_le(b + 1, (void *) w_le);
168}
169
170static int sm_find_free(void *addr, unsigned begin, unsigned end,
171 unsigned *result)
172{
173 while (begin < end) {
174 if (!(begin & (ENTRIES_PER_WORD - 1)) &&
175 dm_bitmap_word_used(addr, begin)) {
176 begin += ENTRIES_PER_WORD;
177 continue;
178 }
179
180 if (!sm_lookup_bitmap(addr, begin)) {
181 *result = begin;
182 return 0;
183 }
184
185 begin++;
186 }
187
188 return -ENOSPC;
189}
190
191/*----------------------------------------------------------------*/
192
193static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
194{
195 memset(ll, 0, sizeof(struct ll_disk));
196
197 ll->tm = tm;
198
199 ll->bitmap_info.tm = tm;
200 ll->bitmap_info.levels = 1;
201
202 /*
203 * Because the new bitmap blocks are created via a shadow
204 * operation, the old entry has already had its reference count
205 * decremented and we don't need the btree to do any bookkeeping.
206 */
207 ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
208 ll->bitmap_info.value_type.inc = NULL;
209 ll->bitmap_info.value_type.dec = NULL;
210 ll->bitmap_info.value_type.equal = NULL;
211
212 ll->ref_count_info.tm = tm;
213 ll->ref_count_info.levels = 1;
214 ll->ref_count_info.value_type.size = sizeof(uint32_t);
215 ll->ref_count_info.value_type.inc = NULL;
216 ll->ref_count_info.value_type.dec = NULL;
217 ll->ref_count_info.value_type.equal = NULL;
218
219 ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
220
221 if (ll->block_size > (1 << 30)) {
222 DMERR("block size too big to hold bitmaps");
223 return -EINVAL;
224 }
225
226 ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
227 ENTRIES_PER_BYTE;
228 ll->nr_blocks = 0;
229 ll->bitmap_root = 0;
230 ll->ref_count_root = 0;
231 ll->bitmap_index_changed = false;
232
233 return 0;
234}
235
236int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
237{
238 int r;
239 dm_block_t i, nr_blocks, nr_indexes;
240 unsigned old_blocks, blocks;
241
242 nr_blocks = ll->nr_blocks + extra_blocks;
243 old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
244 blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
245
246 nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
247 if (nr_indexes > ll->max_entries(ll)) {
248 DMERR("space map too large");
249 return -EINVAL;
250 }
251
252 /*
253 * We need to set this before the dm_tm_new_block() call below.
254 */
255 ll->nr_blocks = nr_blocks;
256 for (i = old_blocks; i < blocks; i++) {
257 struct dm_block *b;
258 struct disk_index_entry idx;
259
260 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
261 if (r < 0)
262 return r;
263
264 idx.blocknr = cpu_to_le64(dm_block_location(b));
265
266 dm_tm_unlock(ll->tm, b);
267
268 idx.nr_free = cpu_to_le32(ll->entries_per_block);
269 idx.none_free_before = 0;
270
271 r = ll->save_ie(ll, i, &idx);
272 if (r < 0)
273 return r;
274 }
275
276 return 0;
277}
278
279int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
280{
281 int r;
282 dm_block_t index = b;
283 struct disk_index_entry ie_disk;
284 struct dm_block *blk;
285
286 b = do_div(index, ll->entries_per_block);
287 r = ll->load_ie(ll, index, &ie_disk);
288 if (r < 0)
289 return r;
290
291 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
292 &dm_sm_bitmap_validator, &blk);
293 if (r < 0)
294 return r;
295
296 *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
297
298 dm_tm_unlock(ll->tm, blk);
299
300 return 0;
301}
302
303static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
304 uint32_t *result)
305{
306 __le32 le_rc;
307 int r;
308
309 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
310 if (r < 0)
311 return r;
312
313 *result = le32_to_cpu(le_rc);
314
315 return r;
316}
317
318int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
319{
320 int r = sm_ll_lookup_bitmap(ll, b, result);
321
322 if (r)
323 return r;
324
325 if (*result != 3)
326 return r;
327
328 return sm_ll_lookup_big_ref_count(ll, b, result);
329}
330
331int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
332 dm_block_t end, dm_block_t *result)
333{
334 int r;
335 struct disk_index_entry ie_disk;
336 dm_block_t i, index_begin = begin;
337 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
338
339 /*
340 * FIXME: Use shifts
341 */
342 begin = do_div(index_begin, ll->entries_per_block);
343 end = do_div(end, ll->entries_per_block);
344 if (end == 0)
345 end = ll->entries_per_block;
346
347 for (i = index_begin; i < index_end; i++, begin = 0) {
348 struct dm_block *blk;
349 unsigned position;
350 uint32_t bit_end;
351
352 r = ll->load_ie(ll, i, &ie_disk);
353 if (r < 0)
354 return r;
355
356 if (le32_to_cpu(ie_disk.nr_free) == 0)
357 continue;
358
359 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
360 &dm_sm_bitmap_validator, &blk);
361 if (r < 0)
362 return r;
363
364 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
365
366 r = sm_find_free(dm_bitmap_data(blk),
367 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
368 bit_end, &position);
369 if (r == -ENOSPC) {
370 /*
371 * This might happen because we started searching
372 * part way through the bitmap.
373 */
374 dm_tm_unlock(ll->tm, blk);
375 continue;
376 }
377
378 dm_tm_unlock(ll->tm, blk);
379
380 *result = i * ll->entries_per_block + (dm_block_t) position;
381 return 0;
382 }
383
384 return -ENOSPC;
385}
386
387int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
388 dm_block_t begin, dm_block_t end, dm_block_t *b)
389{
390 int r;
391 uint32_t count;
392
393 do {
394 r = sm_ll_find_free_block(new_ll, begin, new_ll->nr_blocks, b);
395 if (r)
396 break;
397
398 /* double check this block wasn't used in the old transaction */
399 if (*b >= old_ll->nr_blocks)
400 count = 0;
401 else {
402 r = sm_ll_lookup(old_ll, *b, &count);
403 if (r)
404 break;
405
406 if (count)
407 begin = *b + 1;
408 }
409 } while (count);
410
411 return r;
412}
413
414/*----------------------------------------------------------------*/
415
416int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
417 uint32_t ref_count, int32_t *nr_allocations)
418{
419 int r;
420 uint32_t bit, old;
421 struct dm_block *nb;
422 dm_block_t index = b;
423 struct disk_index_entry ie_disk;
424 void *bm_le;
425 int inc;
426
427 bit = do_div(index, ll->entries_per_block);
428 r = ll->load_ie(ll, index, &ie_disk);
429 if (r < 0)
430 return r;
431
432 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
433 &dm_sm_bitmap_validator, &nb, &inc);
434 if (r < 0) {
435 DMERR("dm_tm_shadow_block() failed");
436 return r;
437 }
438 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
439 bm_le = dm_bitmap_data(nb);
440
441 old = sm_lookup_bitmap(bm_le, bit);
442 if (old > 2) {
443 r = sm_ll_lookup_big_ref_count(ll, b, &old);
444 if (r < 0) {
445 dm_tm_unlock(ll->tm, nb);
446 return r;
447 }
448 }
449
450 if (r) {
451 dm_tm_unlock(ll->tm, nb);
452 return r;
453 }
454
455 if (ref_count <= 2) {
456 sm_set_bitmap(bm_le, bit, ref_count);
457 dm_tm_unlock(ll->tm, nb);
458
459 if (old > 2) {
460 r = dm_btree_remove(&ll->ref_count_info,
461 ll->ref_count_root,
462 &b, &ll->ref_count_root);
463 if (r)
464 return r;
465 }
466
467 } else {
468 __le32 le_rc = cpu_to_le32(ref_count);
469
470 sm_set_bitmap(bm_le, bit, 3);
471 dm_tm_unlock(ll->tm, nb);
472
473 __dm_bless_for_disk(&le_rc);
474 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
475 &b, &le_rc, &ll->ref_count_root);
476 if (r < 0) {
477 DMERR("ref count insert failed");
478 return r;
479 }
480 }
481
482 if (ref_count && !old) {
483 *nr_allocations = 1;
484 ll->nr_allocated++;
485 le32_add_cpu(&ie_disk.nr_free, -1);
486 if (le32_to_cpu(ie_disk.none_free_before) == bit)
487 ie_disk.none_free_before = cpu_to_le32(bit + 1);
488
489 } else if (old && !ref_count) {
490 *nr_allocations = -1;
491 ll->nr_allocated--;
492 le32_add_cpu(&ie_disk.nr_free, 1);
493 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
494 } else
495 *nr_allocations = 0;
496
497 return ll->save_ie(ll, index, &ie_disk);
498}
499
500/*----------------------------------------------------------------*/
501
502/*
503 * Holds useful intermediate results for the range based inc and dec
504 * operations.
505 */
506struct inc_context {
507 struct disk_index_entry ie_disk;
508 struct dm_block *bitmap_block;
509 void *bitmap;
510
511 struct dm_block *overflow_leaf;
512};
513
514static inline void init_inc_context(struct inc_context *ic)
515{
516 ic->bitmap_block = NULL;
517 ic->bitmap = NULL;
518 ic->overflow_leaf = NULL;
519}
520
521static inline void exit_inc_context(struct ll_disk *ll, struct inc_context *ic)
522{
523 if (ic->bitmap_block)
524 dm_tm_unlock(ll->tm, ic->bitmap_block);
525 if (ic->overflow_leaf)
526 dm_tm_unlock(ll->tm, ic->overflow_leaf);
527}
528
529static inline void reset_inc_context(struct ll_disk *ll, struct inc_context *ic)
530{
531 exit_inc_context(ll, ic);
532 init_inc_context(ic);
533}
534
535/*
536 * Confirms a btree node contains a particular key at an index.
537 */
538static bool contains_key(struct btree_node *n, uint64_t key, int index)
539{
540 return index >= 0 &&
541 index < le32_to_cpu(n->header.nr_entries) &&
542 le64_to_cpu(n->keys[index]) == key;
543}
544
545static int __sm_ll_inc_overflow(struct ll_disk *ll, dm_block_t b, struct inc_context *ic)
546{
547 int r;
548 int index;
549 struct btree_node *n;
550 __le32 *v_ptr;
551 uint32_t rc;
552
553 /*
554 * bitmap_block needs to be unlocked because getting the
555 * overflow_leaf may need to allocate, and thus use the space map.
556 */
557 reset_inc_context(ll, ic);
558
559 r = btree_get_overwrite_leaf(&ll->ref_count_info, ll->ref_count_root,
560 b, &index, &ll->ref_count_root, &ic->overflow_leaf);
561 if (r < 0)
562 return r;
563
564 n = dm_block_data(ic->overflow_leaf);
565
566 if (!contains_key(n, b, index)) {
567 DMERR("overflow btree is missing an entry");
568 return -EINVAL;
569 }
570
571 v_ptr = value_ptr(n, index);
572 rc = le32_to_cpu(*v_ptr) + 1;
573 *v_ptr = cpu_to_le32(rc);
574
575 return 0;
576}
577
578static int sm_ll_inc_overflow(struct ll_disk *ll, dm_block_t b, struct inc_context *ic)
579{
580 int index;
581 struct btree_node *n;
582 __le32 *v_ptr;
583 uint32_t rc;
584
585 /*
586 * Do we already have the correct overflow leaf?
587 */
588 if (ic->overflow_leaf) {
589 n = dm_block_data(ic->overflow_leaf);
590 index = lower_bound(n, b);
591 if (contains_key(n, b, index)) {
592 v_ptr = value_ptr(n, index);
593 rc = le32_to_cpu(*v_ptr) + 1;
594 *v_ptr = cpu_to_le32(rc);
595
596 return 0;
597 }
598 }
599
600 return __sm_ll_inc_overflow(ll, b, ic);
601}
602
603static inline int shadow_bitmap(struct ll_disk *ll, struct inc_context *ic)
604{
605 int r, inc;
606 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ic->ie_disk.blocknr),
607 &dm_sm_bitmap_validator, &ic->bitmap_block, &inc);
608 if (r < 0) {
609 DMERR("dm_tm_shadow_block() failed");
610 return r;
611 }
612 ic->ie_disk.blocknr = cpu_to_le64(dm_block_location(ic->bitmap_block));
613 ic->bitmap = dm_bitmap_data(ic->bitmap_block);
614 return 0;
615}
616
617/*
618 * Once shadow_bitmap has been called, which always happens at the start of inc/dec,
619 * we can reopen the bitmap with a simple write lock, rather than re calling
620 * dm_tm_shadow_block().
621 */
622static inline int ensure_bitmap(struct ll_disk *ll, struct inc_context *ic)
623{
624 if (!ic->bitmap_block) {
625 int r = dm_bm_write_lock(dm_tm_get_bm(ll->tm), le64_to_cpu(ic->ie_disk.blocknr),
626 &dm_sm_bitmap_validator, &ic->bitmap_block);
627 if (r) {
628 DMERR("unable to re-get write lock for bitmap");
629 return r;
630 }
631 ic->bitmap = dm_bitmap_data(ic->bitmap_block);
632 }
633
634 return 0;
635}
636
637/*
638 * Loops round incrementing entries in a single bitmap.
639 */
640static inline int sm_ll_inc_bitmap(struct ll_disk *ll, dm_block_t b,
641 uint32_t bit, uint32_t bit_end,
642 int32_t *nr_allocations, dm_block_t *new_b,
643 struct inc_context *ic)
644{
645 int r;
646 __le32 le_rc;
647 uint32_t old;
648
649 for (; bit != bit_end; bit++, b++) {
650 /*
651 * We only need to drop the bitmap if we need to find a new btree
652 * leaf for the overflow. So if it was dropped last iteration,
653 * we now re-get it.
654 */
655 r = ensure_bitmap(ll, ic);
656 if (r)
657 return r;
658
659 old = sm_lookup_bitmap(ic->bitmap, bit);
660 switch (old) {
661 case 0:
662 /* inc bitmap, adjust nr_allocated */
663 sm_set_bitmap(ic->bitmap, bit, 1);
664 (*nr_allocations)++;
665 ll->nr_allocated++;
666 le32_add_cpu(&ic->ie_disk.nr_free, -1);
667 if (le32_to_cpu(ic->ie_disk.none_free_before) == bit)
668 ic->ie_disk.none_free_before = cpu_to_le32(bit + 1);
669 break;
670
671 case 1:
672 /* inc bitmap */
673 sm_set_bitmap(ic->bitmap, bit, 2);
674 break;
675
676 case 2:
677 /* inc bitmap and insert into overflow */
678 sm_set_bitmap(ic->bitmap, bit, 3);
679 reset_inc_context(ll, ic);
680
681 le_rc = cpu_to_le32(3);
682 __dm_bless_for_disk(&le_rc);
683 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
684 &b, &le_rc, &ll->ref_count_root);
685 if (r < 0) {
686 DMERR("ref count insert failed");
687 return r;
688 }
689 break;
690
691 default:
692 /*
693 * inc within the overflow tree only.
694 */
695 r = sm_ll_inc_overflow(ll, b, ic);
696 if (r < 0)
697 return r;
698 }
699 }
700
701 *new_b = b;
702 return 0;
703}
704
705/*
706 * Finds a bitmap that contains entries in the block range, and increments
707 * them.
708 */
709static int __sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e,
710 int32_t *nr_allocations, dm_block_t *new_b)
711{
712 int r;
713 struct inc_context ic;
714 uint32_t bit, bit_end;
715 dm_block_t index = b;
716
717 init_inc_context(&ic);
718
719 bit = do_div(index, ll->entries_per_block);
720 r = ll->load_ie(ll, index, &ic.ie_disk);
721 if (r < 0)
722 return r;
723
724 r = shadow_bitmap(ll, &ic);
725 if (r)
726 return r;
727
728 bit_end = min(bit + (e - b), (dm_block_t) ll->entries_per_block);
729 r = sm_ll_inc_bitmap(ll, b, bit, bit_end, nr_allocations, new_b, &ic);
730
731 exit_inc_context(ll, &ic);
732
733 if (r)
734 return r;
735
736 return ll->save_ie(ll, index, &ic.ie_disk);
737}
738
739int sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e,
740 int32_t *nr_allocations)
741{
742 *nr_allocations = 0;
743 while (b != e) {
744 int r = __sm_ll_inc(ll, b, e, nr_allocations, &b);
745 if (r)
746 return r;
747 }
748
749 return 0;
750}
751
752/*----------------------------------------------------------------*/
753
754static int __sm_ll_del_overflow(struct ll_disk *ll, dm_block_t b,
755 struct inc_context *ic)
756{
757 reset_inc_context(ll, ic);
758 return dm_btree_remove(&ll->ref_count_info, ll->ref_count_root,
759 &b, &ll->ref_count_root);
760}
761
762static int __sm_ll_dec_overflow(struct ll_disk *ll, dm_block_t b,
763 struct inc_context *ic, uint32_t *old_rc)
764{
765 int r;
766 int index = -1;
767 struct btree_node *n;
768 __le32 *v_ptr;
769 uint32_t rc;
770
771 reset_inc_context(ll, ic);
772 r = btree_get_overwrite_leaf(&ll->ref_count_info, ll->ref_count_root,
773 b, &index, &ll->ref_count_root, &ic->overflow_leaf);
774 if (r < 0)
775 return r;
776
777 n = dm_block_data(ic->overflow_leaf);
778
779 if (!contains_key(n, b, index)) {
780 DMERR("overflow btree is missing an entry");
781 return -EINVAL;
782 }
783
784 v_ptr = value_ptr(n, index);
785 rc = le32_to_cpu(*v_ptr);
786 *old_rc = rc;
787
788 if (rc == 3) {
789 return __sm_ll_del_overflow(ll, b, ic);
790 } else {
791 rc--;
792 *v_ptr = cpu_to_le32(rc);
793 return 0;
794 }
795}
796
797static int sm_ll_dec_overflow(struct ll_disk *ll, dm_block_t b,
798 struct inc_context *ic, uint32_t *old_rc)
799{
800 /*
801 * Do we already have the correct overflow leaf?
802 */
803 if (ic->overflow_leaf) {
804 int index;
805 struct btree_node *n;
806 __le32 *v_ptr;
807 uint32_t rc;
808
809 n = dm_block_data(ic->overflow_leaf);
810 index = lower_bound(n, b);
811 if (contains_key(n, b, index)) {
812 v_ptr = value_ptr(n, index);
813 rc = le32_to_cpu(*v_ptr);
814 *old_rc = rc;
815
816 if (rc > 3) {
817 rc--;
818 *v_ptr = cpu_to_le32(rc);
819 return 0;
820 } else {
821 return __sm_ll_del_overflow(ll, b, ic);
822 }
823
824 }
825 }
826
827 return __sm_ll_dec_overflow(ll, b, ic, old_rc);
828}
829
830/*
831 * Loops round incrementing entries in a single bitmap.
832 */
833static inline int sm_ll_dec_bitmap(struct ll_disk *ll, dm_block_t b,
834 uint32_t bit, uint32_t bit_end,
835 struct inc_context *ic,
836 int32_t *nr_allocations, dm_block_t *new_b)
837{
838 int r;
839 uint32_t old;
840
841 for (; bit != bit_end; bit++, b++) {
842 /*
843 * We only need to drop the bitmap if we need to find a new btree
844 * leaf for the overflow. So if it was dropped last iteration,
845 * we now re-get it.
846 */
847 r = ensure_bitmap(ll, ic);
848 if (r)
849 return r;
850
851 old = sm_lookup_bitmap(ic->bitmap, bit);
852 switch (old) {
853 case 0:
854 DMERR("unable to decrement block");
855 return -EINVAL;
856
857 case 1:
858 /* dec bitmap */
859 sm_set_bitmap(ic->bitmap, bit, 0);
860 (*nr_allocations)--;
861 ll->nr_allocated--;
862 le32_add_cpu(&ic->ie_disk.nr_free, 1);
863 ic->ie_disk.none_free_before =
864 cpu_to_le32(min(le32_to_cpu(ic->ie_disk.none_free_before), bit));
865 break;
866
867 case 2:
868 /* dec bitmap and insert into overflow */
869 sm_set_bitmap(ic->bitmap, bit, 1);
870 break;
871
872 case 3:
873 r = sm_ll_dec_overflow(ll, b, ic, &old);
874 if (r < 0)
875 return r;
876
877 if (old == 3) {
878 r = ensure_bitmap(ll, ic);
879 if (r)
880 return r;
881
882 sm_set_bitmap(ic->bitmap, bit, 2);
883 }
884 break;
885 }
886 }
887
888 *new_b = b;
889 return 0;
890}
891
892static int __sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e,
893 int32_t *nr_allocations, dm_block_t *new_b)
894{
895 int r;
896 uint32_t bit, bit_end;
897 struct inc_context ic;
898 dm_block_t index = b;
899
900 init_inc_context(&ic);
901
902 bit = do_div(index, ll->entries_per_block);
903 r = ll->load_ie(ll, index, &ic.ie_disk);
904 if (r < 0)
905 return r;
906
907 r = shadow_bitmap(ll, &ic);
908 if (r)
909 return r;
910
911 bit_end = min(bit + (e - b), (dm_block_t) ll->entries_per_block);
912 r = sm_ll_dec_bitmap(ll, b, bit, bit_end, &ic, nr_allocations, new_b);
913 exit_inc_context(ll, &ic);
914
915 if (r)
916 return r;
917
918 return ll->save_ie(ll, index, &ic.ie_disk);
919}
920
921int sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e,
922 int32_t *nr_allocations)
923{
924 *nr_allocations = 0;
925 while (b != e) {
926 int r = __sm_ll_dec(ll, b, e, nr_allocations, &b);
927 if (r)
928 return r;
929 }
930
931 return 0;
932}
933
934/*----------------------------------------------------------------*/
935
936int sm_ll_commit(struct ll_disk *ll)
937{
938 int r = 0;
939
940 if (ll->bitmap_index_changed) {
941 r = ll->commit(ll);
942 if (!r)
943 ll->bitmap_index_changed = false;
944 }
945
946 return r;
947}
948
949/*----------------------------------------------------------------*/
950
951static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
952 struct disk_index_entry *ie)
953{
954 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
955 return 0;
956}
957
958static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
959 struct disk_index_entry *ie)
960{
961 ll->bitmap_index_changed = true;
962 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
963 return 0;
964}
965
966static int metadata_ll_init_index(struct ll_disk *ll)
967{
968 int r;
969 struct dm_block *b;
970
971 r = dm_tm_new_block(ll->tm, &index_validator, &b);
972 if (r < 0)
973 return r;
974
975 ll->bitmap_root = dm_block_location(b);
976
977 dm_tm_unlock(ll->tm, b);
978
979 return 0;
980}
981
982static int metadata_ll_open(struct ll_disk *ll)
983{
984 int r;
985 struct dm_block *block;
986
987 r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
988 &index_validator, &block);
989 if (r)
990 return r;
991
992 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
993 dm_tm_unlock(ll->tm, block);
994
995 return 0;
996}
997
998static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
999{
1000 return MAX_METADATA_BITMAPS;
1001}
1002
1003static int metadata_ll_commit(struct ll_disk *ll)
1004{
1005 int r, inc;
1006 struct dm_block *b;
1007
1008 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
1009 if (r)
1010 return r;
1011
1012 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
1013 ll->bitmap_root = dm_block_location(b);
1014
1015 dm_tm_unlock(ll->tm, b);
1016
1017 return 0;
1018}
1019
1020int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
1021{
1022 int r;
1023
1024 r = sm_ll_init(ll, tm);
1025 if (r < 0)
1026 return r;
1027
1028 ll->load_ie = metadata_ll_load_ie;
1029 ll->save_ie = metadata_ll_save_ie;
1030 ll->init_index = metadata_ll_init_index;
1031 ll->open_index = metadata_ll_open;
1032 ll->max_entries = metadata_ll_max_entries;
1033 ll->commit = metadata_ll_commit;
1034
1035 ll->nr_blocks = 0;
1036 ll->nr_allocated = 0;
1037
1038 r = ll->init_index(ll);
1039 if (r < 0)
1040 return r;
1041
1042 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
1043 if (r < 0)
1044 return r;
1045
1046 return 0;
1047}
1048
1049int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
1050 void *root_le, size_t len)
1051{
1052 int r;
1053 struct disk_sm_root smr;
1054
1055 if (len < sizeof(struct disk_sm_root)) {
1056 DMERR("sm_metadata root too small");
1057 return -ENOMEM;
1058 }
1059
1060 /*
1061 * We don't know the alignment of the root_le buffer, so need to
1062 * copy into a new structure.
1063 */
1064 memcpy(&smr, root_le, sizeof(smr));
1065
1066 r = sm_ll_init(ll, tm);
1067 if (r < 0)
1068 return r;
1069
1070 ll->load_ie = metadata_ll_load_ie;
1071 ll->save_ie = metadata_ll_save_ie;
1072 ll->init_index = metadata_ll_init_index;
1073 ll->open_index = metadata_ll_open;
1074 ll->max_entries = metadata_ll_max_entries;
1075 ll->commit = metadata_ll_commit;
1076
1077 ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
1078 ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
1079 ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
1080 ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
1081
1082 return ll->open_index(ll);
1083}
1084
1085/*----------------------------------------------------------------*/
1086
1087static inline int ie_cache_writeback(struct ll_disk *ll, struct ie_cache *iec)
1088{
1089 iec->dirty = false;
1090 __dm_bless_for_disk(iec->ie);
1091 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
1092 &iec->index, &iec->ie, &ll->bitmap_root);
1093}
1094
1095static inline unsigned hash_index(dm_block_t index)
1096{
1097 return dm_hash_block(index, IE_CACHE_MASK);
1098}
1099
1100static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
1101 struct disk_index_entry *ie)
1102{
1103 int r;
1104 unsigned h = hash_index(index);
1105 struct ie_cache *iec = ll->ie_cache + h;
1106
1107 if (iec->valid) {
1108 if (iec->index == index) {
1109 memcpy(ie, &iec->ie, sizeof(*ie));
1110 return 0;
1111 }
1112
1113 if (iec->dirty) {
1114 r = ie_cache_writeback(ll, iec);
1115 if (r)
1116 return r;
1117 }
1118 }
1119
1120 r = dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
1121 if (!r) {
1122 iec->valid = true;
1123 iec->dirty = false;
1124 iec->index = index;
1125 memcpy(&iec->ie, ie, sizeof(*ie));
1126 }
1127
1128 return r;
1129}
1130
1131static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
1132 struct disk_index_entry *ie)
1133{
1134 int r;
1135 unsigned h = hash_index(index);
1136 struct ie_cache *iec = ll->ie_cache + h;
1137
1138 ll->bitmap_index_changed = true;
1139 if (iec->valid) {
1140 if (iec->index == index) {
1141 memcpy(&iec->ie, ie, sizeof(*ie));
1142 iec->dirty = true;
1143 return 0;
1144 }
1145
1146 if (iec->dirty) {
1147 r = ie_cache_writeback(ll, iec);
1148 if (r)
1149 return r;
1150 }
1151 }
1152
1153 iec->valid = true;
1154 iec->dirty = true;
1155 iec->index = index;
1156 memcpy(&iec->ie, ie, sizeof(*ie));
1157 return 0;
1158}
1159
1160static int disk_ll_init_index(struct ll_disk *ll)
1161{
1162 unsigned i;
1163 for (i = 0; i < IE_CACHE_SIZE; i++) {
1164 struct ie_cache *iec = ll->ie_cache + i;
1165 iec->valid = false;
1166 iec->dirty = false;
1167 }
1168 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
1169}
1170
1171static int disk_ll_open(struct ll_disk *ll)
1172{
1173 return 0;
1174}
1175
1176static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
1177{
1178 return -1ULL;
1179}
1180
1181static int disk_ll_commit(struct ll_disk *ll)
1182{
1183 int r = 0;
1184 unsigned i;
1185
1186 for (i = 0; i < IE_CACHE_SIZE; i++) {
1187 struct ie_cache *iec = ll->ie_cache + i;
1188 if (iec->valid && iec->dirty)
1189 r = ie_cache_writeback(ll, iec);
1190 }
1191
1192 return r;
1193}
1194
1195int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
1196{
1197 int r;
1198
1199 r = sm_ll_init(ll, tm);
1200 if (r < 0)
1201 return r;
1202
1203 ll->load_ie = disk_ll_load_ie;
1204 ll->save_ie = disk_ll_save_ie;
1205 ll->init_index = disk_ll_init_index;
1206 ll->open_index = disk_ll_open;
1207 ll->max_entries = disk_ll_max_entries;
1208 ll->commit = disk_ll_commit;
1209
1210 ll->nr_blocks = 0;
1211 ll->nr_allocated = 0;
1212
1213 r = ll->init_index(ll);
1214 if (r < 0)
1215 return r;
1216
1217 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
1218 if (r < 0)
1219 return r;
1220
1221 return 0;
1222}
1223
1224int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
1225 void *root_le, size_t len)
1226{
1227 int r;
1228 struct disk_sm_root *smr = root_le;
1229
1230 if (len < sizeof(struct disk_sm_root)) {
1231 DMERR("sm_metadata root too small");
1232 return -ENOMEM;
1233 }
1234
1235 r = sm_ll_init(ll, tm);
1236 if (r < 0)
1237 return r;
1238
1239 ll->load_ie = disk_ll_load_ie;
1240 ll->save_ie = disk_ll_save_ie;
1241 ll->init_index = disk_ll_init_index;
1242 ll->open_index = disk_ll_open;
1243 ll->max_entries = disk_ll_max_entries;
1244 ll->commit = disk_ll_commit;
1245
1246 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
1247 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
1248 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
1249 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
1250
1251 return ll->open_index(ll);
1252}
1253
1254/*----------------------------------------------------------------*/