1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Red Hat, Inc.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm-space-map-common.h"
9#include "dm-transaction-manager.h"
10#include "dm-btree-internal.h"
11#include "dm-persistent-data-internal.h"
12
13#include <linux/bitops.h>
14#include <linux/device-mapper.h>
15
16#define DM_MSG_PREFIX "space map common"
17
18/*----------------------------------------------------------------*/
19
20/*
21 * Index validator.
22 */
23#define INDEX_CSUM_XOR 160478
24
25static void index_prepare_for_write(const struct dm_block_validator *v,
26 struct dm_block *b,
27 size_t block_size)
28{
29 struct disk_metadata_index *mi_le = dm_block_data(b);
30
31 mi_le->blocknr = cpu_to_le64(dm_block_location(b));
32 mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
33 block_size - sizeof(__le32),
34 INDEX_CSUM_XOR));
35}
36
37static int index_check(const struct dm_block_validator *v,
38 struct dm_block *b,
39 size_t block_size)
40{
41 struct disk_metadata_index *mi_le = dm_block_data(b);
42 __le32 csum_disk;
43
44 if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
45 DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
46 le64_to_cpu(mi_le->blocknr), dm_block_location(b));
47 return -ENOTBLK;
48 }
49
50 csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
51 block_size - sizeof(__le32),
52 INDEX_CSUM_XOR));
53 if (csum_disk != mi_le->csum) {
54 DMERR_LIMIT("%s failed: csum %u != wanted %u", __func__,
55 le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
56 return -EILSEQ;
57 }
58
59 return 0;
60}
61
62static const struct dm_block_validator index_validator = {
63 .name = "index",
64 .prepare_for_write = index_prepare_for_write,
65 .check = index_check
66};
67
68/*----------------------------------------------------------------*/
69
70/*
71 * Bitmap validator
72 */
73#define BITMAP_CSUM_XOR 240779
74
75static void dm_bitmap_prepare_for_write(const struct dm_block_validator *v,
76 struct dm_block *b,
77 size_t block_size)
78{
79 struct disk_bitmap_header *disk_header = dm_block_data(b);
80
81 disk_header->blocknr = cpu_to_le64(dm_block_location(b));
82 disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
83 block_size - sizeof(__le32),
84 BITMAP_CSUM_XOR));
85}
86
87static int dm_bitmap_check(const struct dm_block_validator *v,
88 struct dm_block *b,
89 size_t block_size)
90{
91 struct disk_bitmap_header *disk_header = dm_block_data(b);
92 __le32 csum_disk;
93
94 if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
95 DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
96 le64_to_cpu(disk_header->blocknr), dm_block_location(b));
97 return -ENOTBLK;
98 }
99
100 csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
101 block_size - sizeof(__le32),
102 BITMAP_CSUM_XOR));
103 if (csum_disk != disk_header->csum) {
104 DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
105 le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
106 return -EILSEQ;
107 }
108
109 return 0;
110}
111
112static const struct dm_block_validator dm_sm_bitmap_validator = {
113 .name = "sm_bitmap",
114 .prepare_for_write = dm_bitmap_prepare_for_write,
115 .check = dm_bitmap_check,
116};
117
118/*----------------------------------------------------------------*/
119
120#define ENTRIES_PER_WORD 32
121#define ENTRIES_SHIFT 5
122
123static void *dm_bitmap_data(struct dm_block *b)
124{
125 return dm_block_data(b) + sizeof(struct disk_bitmap_header);
126}
127
128#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
129
130static unsigned int dm_bitmap_word_used(void *addr, unsigned int b)
131{
132 __le64 *words_le = addr;
133 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
134
135 uint64_t bits = le64_to_cpu(*w_le);
136 uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
137
138 return !(~bits & mask);
139}
140
141static unsigned int sm_lookup_bitmap(void *addr, unsigned int b)
142{
143 __le64 *words_le = addr;
144 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
145 unsigned int hi, lo;
146
147 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
148 hi = !!test_bit_le(nr: b, addr: (void *) w_le);
149 lo = !!test_bit_le(nr: b + 1, addr: (void *) w_le);
150 return (hi << 1) | lo;
151}
152
153static void sm_set_bitmap(void *addr, unsigned int b, unsigned int val)
154{
155 __le64 *words_le = addr;
156 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
157
158 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
159
160 if (val & 2)
161 __set_bit_le(nr: b, addr: (void *) w_le);
162 else
163 __clear_bit_le(nr: b, addr: (void *) w_le);
164
165 if (val & 1)
166 __set_bit_le(nr: b + 1, addr: (void *) w_le);
167 else
168 __clear_bit_le(nr: b + 1, addr: (void *) w_le);
169}
170
171static int sm_find_free(void *addr, unsigned int begin, unsigned int end,
172 unsigned int *result)
173{
174 while (begin < end) {
175 if (!(begin & (ENTRIES_PER_WORD - 1)) &&
176 dm_bitmap_word_used(addr, b: begin)) {
177 begin += ENTRIES_PER_WORD;
178 continue;
179 }
180
181 if (!sm_lookup_bitmap(addr, b: begin)) {
182 *result = begin;
183 return 0;
184 }
185
186 begin++;
187 }
188
189 return -ENOSPC;
190}
191
192/*----------------------------------------------------------------*/
193
194static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
195{
196 memset(ll, 0, sizeof(struct ll_disk));
197
198 ll->tm = tm;
199
200 ll->bitmap_info.tm = tm;
201 ll->bitmap_info.levels = 1;
202
203 /*
204 * Because the new bitmap blocks are created via a shadow
205 * operation, the old entry has already had its reference count
206 * decremented and we don't need the btree to do any bookkeeping.
207 */
208 ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
209 ll->bitmap_info.value_type.inc = NULL;
210 ll->bitmap_info.value_type.dec = NULL;
211 ll->bitmap_info.value_type.equal = NULL;
212
213 ll->ref_count_info.tm = tm;
214 ll->ref_count_info.levels = 1;
215 ll->ref_count_info.value_type.size = sizeof(uint32_t);
216 ll->ref_count_info.value_type.inc = NULL;
217 ll->ref_count_info.value_type.dec = NULL;
218 ll->ref_count_info.value_type.equal = NULL;
219
220 ll->block_size = dm_bm_block_size(bm: dm_tm_get_bm(tm));
221
222 if (ll->block_size > (1 << 30)) {
223 DMERR("block size too big to hold bitmaps");
224 return -EINVAL;
225 }
226
227 ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
228 ENTRIES_PER_BYTE;
229 ll->nr_blocks = 0;
230 ll->bitmap_root = 0;
231 ll->ref_count_root = 0;
232 ll->bitmap_index_changed = false;
233
234 return 0;
235}
236
237int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
238{
239 int r;
240 dm_block_t i, nr_blocks, nr_indexes;
241 unsigned int old_blocks, blocks;
242
243 nr_blocks = ll->nr_blocks + extra_blocks;
244 old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
245 blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
246
247 nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
248 if (nr_indexes > ll->max_entries(ll)) {
249 DMERR("space map too large");
250 return -EINVAL;
251 }
252
253 /*
254 * We need to set this before the dm_tm_new_block() call below.
255 */
256 ll->nr_blocks = nr_blocks;
257 for (i = old_blocks; i < blocks; i++) {
258 struct dm_block *b;
259 struct disk_index_entry idx;
260
261 r = dm_tm_new_block(tm: ll->tm, v: &dm_sm_bitmap_validator, result: &b);
262 if (r < 0)
263 return r;
264
265 idx.blocknr = cpu_to_le64(dm_block_location(b));
266
267 dm_tm_unlock(tm: ll->tm, b);
268
269 idx.nr_free = cpu_to_le32(ll->entries_per_block);
270 idx.none_free_before = 0;
271
272 r = ll->save_ie(ll, i, &idx);
273 if (r < 0)
274 return r;
275 }
276
277 return 0;
278}
279
280int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
281{
282 int r;
283 dm_block_t index = b;
284 struct disk_index_entry ie_disk;
285 struct dm_block *blk;
286
287 if (b >= ll->nr_blocks) {
288 DMERR_LIMIT("metadata block out of bounds");
289 return -EINVAL;
290 }
291
292 b = do_div(index, ll->entries_per_block);
293 r = ll->load_ie(ll, index, &ie_disk);
294 if (r < 0)
295 return r;
296
297 r = dm_tm_read_lock(tm: ll->tm, le64_to_cpu(ie_disk.blocknr),
298 v: &dm_sm_bitmap_validator, result: &blk);
299 if (r < 0)
300 return r;
301
302 *result = sm_lookup_bitmap(addr: dm_bitmap_data(b: blk), b);
303
304 dm_tm_unlock(tm: ll->tm, b: blk);
305
306 return 0;
307}
308
309static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
310 uint32_t *result)
311{
312 __le32 le_rc;
313 int r;
314
315 r = dm_btree_lookup(info: &ll->ref_count_info, root: ll->ref_count_root, keys: &b, value_le: &le_rc);
316 if (r < 0)
317 return r;
318
319 *result = le32_to_cpu(le_rc);
320
321 return r;
322}
323
324int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
325{
326 int r = sm_ll_lookup_bitmap(ll, b, result);
327
328 if (r)
329 return r;
330
331 if (*result != 3)
332 return r;
333
334 return sm_ll_lookup_big_ref_count(ll, b, result);
335}
336
337int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
338 dm_block_t end, dm_block_t *result)
339{
340 int r;
341 struct disk_index_entry ie_disk;
342 dm_block_t i, index_begin = begin;
343 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
344
345 /*
346 * FIXME: Use shifts
347 */
348 begin = do_div(index_begin, ll->entries_per_block);
349 end = do_div(end, ll->entries_per_block);
350 if (end == 0)
351 end = ll->entries_per_block;
352
353 for (i = index_begin; i < index_end; i++, begin = 0) {
354 struct dm_block *blk;
355 unsigned int position;
356 uint32_t bit_end;
357
358 r = ll->load_ie(ll, i, &ie_disk);
359 if (r < 0)
360 return r;
361
362 if (le32_to_cpu(ie_disk.nr_free) == 0)
363 continue;
364
365 r = dm_tm_read_lock(tm: ll->tm, le64_to_cpu(ie_disk.blocknr),
366 v: &dm_sm_bitmap_validator, result: &blk);
367 if (r < 0)
368 return r;
369
370 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
371
372 r = sm_find_free(addr: dm_bitmap_data(b: blk),
373 max_t(unsigned int, begin, le32_to_cpu(ie_disk.none_free_before)),
374 end: bit_end, result: &position);
375 if (r == -ENOSPC) {
376 /*
377 * This might happen because we started searching
378 * part way through the bitmap.
379 */
380 dm_tm_unlock(tm: ll->tm, b: blk);
381 continue;
382 }
383
384 dm_tm_unlock(tm: ll->tm, b: blk);
385
386 *result = i * ll->entries_per_block + (dm_block_t) position;
387 return 0;
388 }
389
390 return -ENOSPC;
391}
392
393int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
394 dm_block_t begin, dm_block_t end, dm_block_t *b)
395{
396 int r;
397 uint32_t count;
398
399 do {
400 r = sm_ll_find_free_block(ll: new_ll, begin, end: new_ll->nr_blocks, result: b);
401 if (r)
402 break;
403
404 /* double check this block wasn't used in the old transaction */
405 if (*b >= old_ll->nr_blocks)
406 count = 0;
407 else {
408 r = sm_ll_lookup(ll: old_ll, b: *b, result: &count);
409 if (r)
410 break;
411
412 if (count)
413 begin = *b + 1;
414 }
415 } while (count);
416
417 return r;
418}
419
420/*----------------------------------------------------------------*/
421
422int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
423 uint32_t ref_count, int32_t *nr_allocations)
424{
425 int r;
426 uint32_t bit, old;
427 struct dm_block *nb;
428 dm_block_t index = b;
429 struct disk_index_entry ie_disk;
430 void *bm_le;
431 int inc;
432
433 bit = do_div(index, ll->entries_per_block);
434 r = ll->load_ie(ll, index, &ie_disk);
435 if (r < 0)
436 return r;
437
438 r = dm_tm_shadow_block(tm: ll->tm, le64_to_cpu(ie_disk.blocknr),
439 v: &dm_sm_bitmap_validator, result: &nb, inc_children: &inc);
440 if (r < 0) {
441 DMERR("dm_tm_shadow_block() failed");
442 return r;
443 }
444 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
445 bm_le = dm_bitmap_data(b: nb);
446
447 old = sm_lookup_bitmap(addr: bm_le, b: bit);
448 if (old > 2) {
449 r = sm_ll_lookup_big_ref_count(ll, b, result: &old);
450 if (r < 0) {
451 dm_tm_unlock(tm: ll->tm, b: nb);
452 return r;
453 }
454 }
455
456 if (r) {
457 dm_tm_unlock(tm: ll->tm, b: nb);
458 return r;
459 }
460
461 if (ref_count <= 2) {
462 sm_set_bitmap(addr: bm_le, b: bit, val: ref_count);
463 dm_tm_unlock(tm: ll->tm, b: nb);
464
465 if (old > 2) {
466 r = dm_btree_remove(info: &ll->ref_count_info,
467 root: ll->ref_count_root,
468 keys: &b, new_root: &ll->ref_count_root);
469 if (r)
470 return r;
471 }
472
473 } else {
474 __le32 le_rc = cpu_to_le32(ref_count);
475
476 sm_set_bitmap(addr: bm_le, b: bit, val: 3);
477 dm_tm_unlock(tm: ll->tm, b: nb);
478
479 __dm_bless_for_disk(&le_rc);
480 r = dm_btree_insert(info: &ll->ref_count_info, root: ll->ref_count_root,
481 keys: &b, value: &le_rc, new_root: &ll->ref_count_root);
482 if (r < 0) {
483 DMERR("ref count insert failed");
484 return r;
485 }
486 }
487
488 if (ref_count && !old) {
489 *nr_allocations = 1;
490 ll->nr_allocated++;
491 le32_add_cpu(var: &ie_disk.nr_free, val: -1);
492 if (le32_to_cpu(ie_disk.none_free_before) == bit)
493 ie_disk.none_free_before = cpu_to_le32(bit + 1);
494
495 } else if (old && !ref_count) {
496 *nr_allocations = -1;
497 ll->nr_allocated--;
498 le32_add_cpu(var: &ie_disk.nr_free, val: 1);
499 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
500 } else
501 *nr_allocations = 0;
502
503 return ll->save_ie(ll, index, &ie_disk);
504}
505
506/*----------------------------------------------------------------*/
507
508/*
509 * Holds useful intermediate results for the range based inc and dec
510 * operations.
511 */
512struct inc_context {
513 struct disk_index_entry ie_disk;
514 struct dm_block *bitmap_block;
515 void *bitmap;
516
517 struct dm_block *overflow_leaf;
518};
519
520static inline void init_inc_context(struct inc_context *ic)
521{
522 ic->bitmap_block = NULL;
523 ic->bitmap = NULL;
524 ic->overflow_leaf = NULL;
525}
526
527static inline void exit_inc_context(struct ll_disk *ll, struct inc_context *ic)
528{
529 if (ic->bitmap_block)
530 dm_tm_unlock(tm: ll->tm, b: ic->bitmap_block);
531 if (ic->overflow_leaf)
532 dm_tm_unlock(tm: ll->tm, b: ic->overflow_leaf);
533}
534
535static inline void reset_inc_context(struct ll_disk *ll, struct inc_context *ic)
536{
537 exit_inc_context(ll, ic);
538 init_inc_context(ic);
539}
540
541/*
542 * Confirms a btree node contains a particular key at an index.
543 */
544static bool contains_key(struct btree_node *n, uint64_t key, int index)
545{
546 return index >= 0 &&
547 index < le32_to_cpu(n->header.nr_entries) &&
548 le64_to_cpu(n->keys[index]) == key;
549}
550
551static int __sm_ll_inc_overflow(struct ll_disk *ll, dm_block_t b, struct inc_context *ic)
552{
553 int r;
554 int index;
555 struct btree_node *n;
556 __le32 *v_ptr;
557 uint32_t rc;
558
559 /*
560 * bitmap_block needs to be unlocked because getting the
561 * overflow_leaf may need to allocate, and thus use the space map.
562 */
563 reset_inc_context(ll, ic);
564
565 r = btree_get_overwrite_leaf(info: &ll->ref_count_info, root: ll->ref_count_root,
566 key: b, index: &index, new_root: &ll->ref_count_root, leaf: &ic->overflow_leaf);
567 if (r < 0)
568 return r;
569
570 n = dm_block_data(b: ic->overflow_leaf);
571
572 if (!contains_key(n, key: b, index)) {
573 DMERR("overflow btree is missing an entry");
574 return -EINVAL;
575 }
576
577 v_ptr = value_ptr(n, index);
578 rc = le32_to_cpu(*v_ptr) + 1;
579 *v_ptr = cpu_to_le32(rc);
580
581 return 0;
582}
583
584static int sm_ll_inc_overflow(struct ll_disk *ll, dm_block_t b, struct inc_context *ic)
585{
586 int index;
587 struct btree_node *n;
588 __le32 *v_ptr;
589 uint32_t rc;
590
591 /*
592 * Do we already have the correct overflow leaf?
593 */
594 if (ic->overflow_leaf) {
595 n = dm_block_data(b: ic->overflow_leaf);
596 index = lower_bound(n, key: b);
597 if (contains_key(n, key: b, index)) {
598 v_ptr = value_ptr(n, index);
599 rc = le32_to_cpu(*v_ptr) + 1;
600 *v_ptr = cpu_to_le32(rc);
601
602 return 0;
603 }
604 }
605
606 return __sm_ll_inc_overflow(ll, b, ic);
607}
608
609static inline int shadow_bitmap(struct ll_disk *ll, struct inc_context *ic)
610{
611 int r, inc;
612
613 r = dm_tm_shadow_block(tm: ll->tm, le64_to_cpu(ic->ie_disk.blocknr),
614 v: &dm_sm_bitmap_validator, result: &ic->bitmap_block, inc_children: &inc);
615 if (r < 0) {
616 DMERR("dm_tm_shadow_block() failed");
617 return r;
618 }
619 ic->ie_disk.blocknr = cpu_to_le64(dm_block_location(ic->bitmap_block));
620 ic->bitmap = dm_bitmap_data(b: ic->bitmap_block);
621 return 0;
622}
623
624/*
625 * Once shadow_bitmap has been called, which always happens at the start of inc/dec,
626 * we can reopen the bitmap with a simple write lock, rather than re calling
627 * dm_tm_shadow_block().
628 */
629static inline int ensure_bitmap(struct ll_disk *ll, struct inc_context *ic)
630{
631 if (!ic->bitmap_block) {
632 int r = dm_bm_write_lock(bm: dm_tm_get_bm(tm: ll->tm), le64_to_cpu(ic->ie_disk.blocknr),
633 v: &dm_sm_bitmap_validator, result: &ic->bitmap_block);
634 if (r) {
635 DMERR("unable to re-get write lock for bitmap");
636 return r;
637 }
638 ic->bitmap = dm_bitmap_data(b: ic->bitmap_block);
639 }
640
641 return 0;
642}
643
644/*
645 * Loops round incrementing entries in a single bitmap.
646 */
647static inline int sm_ll_inc_bitmap(struct ll_disk *ll, dm_block_t b,
648 uint32_t bit, uint32_t bit_end,
649 int32_t *nr_allocations, dm_block_t *new_b,
650 struct inc_context *ic)
651{
652 int r;
653 __le32 le_rc;
654 uint32_t old;
655
656 for (; bit != bit_end; bit++, b++) {
657 /*
658 * We only need to drop the bitmap if we need to find a new btree
659 * leaf for the overflow. So if it was dropped last iteration,
660 * we now re-get it.
661 */
662 r = ensure_bitmap(ll, ic);
663 if (r)
664 return r;
665
666 old = sm_lookup_bitmap(addr: ic->bitmap, b: bit);
667 switch (old) {
668 case 0:
669 /* inc bitmap, adjust nr_allocated */
670 sm_set_bitmap(addr: ic->bitmap, b: bit, val: 1);
671 (*nr_allocations)++;
672 ll->nr_allocated++;
673 le32_add_cpu(var: &ic->ie_disk.nr_free, val: -1);
674 if (le32_to_cpu(ic->ie_disk.none_free_before) == bit)
675 ic->ie_disk.none_free_before = cpu_to_le32(bit + 1);
676 break;
677
678 case 1:
679 /* inc bitmap */
680 sm_set_bitmap(addr: ic->bitmap, b: bit, val: 2);
681 break;
682
683 case 2:
684 /* inc bitmap and insert into overflow */
685 sm_set_bitmap(addr: ic->bitmap, b: bit, val: 3);
686 reset_inc_context(ll, ic);
687
688 le_rc = cpu_to_le32(3);
689 __dm_bless_for_disk(&le_rc);
690 r = dm_btree_insert(info: &ll->ref_count_info, root: ll->ref_count_root,
691 keys: &b, value: &le_rc, new_root: &ll->ref_count_root);
692 if (r < 0) {
693 DMERR("ref count insert failed");
694 return r;
695 }
696 break;
697
698 default:
699 /*
700 * inc within the overflow tree only.
701 */
702 r = sm_ll_inc_overflow(ll, b, ic);
703 if (r < 0)
704 return r;
705 }
706 }
707
708 *new_b = b;
709 return 0;
710}
711
712/*
713 * Finds a bitmap that contains entries in the block range, and increments
714 * them.
715 */
716static int __sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e,
717 int32_t *nr_allocations, dm_block_t *new_b)
718{
719 int r;
720 struct inc_context ic;
721 uint32_t bit, bit_end;
722 dm_block_t index = b;
723
724 init_inc_context(ic: &ic);
725
726 bit = do_div(index, ll->entries_per_block);
727 r = ll->load_ie(ll, index, &ic.ie_disk);
728 if (r < 0)
729 return r;
730
731 r = shadow_bitmap(ll, ic: &ic);
732 if (r)
733 return r;
734
735 bit_end = min(bit + (e - b), (dm_block_t) ll->entries_per_block);
736 r = sm_ll_inc_bitmap(ll, b, bit, bit_end, nr_allocations, new_b, ic: &ic);
737
738 exit_inc_context(ll, ic: &ic);
739
740 if (r)
741 return r;
742
743 return ll->save_ie(ll, index, &ic.ie_disk);
744}
745
746int sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e,
747 int32_t *nr_allocations)
748{
749 *nr_allocations = 0;
750 while (b != e) {
751 int r = __sm_ll_inc(ll, b, e, nr_allocations, new_b: &b);
752
753 if (r)
754 return r;
755 }
756
757 return 0;
758}
759
760/*----------------------------------------------------------------*/
761
762static int __sm_ll_del_overflow(struct ll_disk *ll, dm_block_t b,
763 struct inc_context *ic)
764{
765 reset_inc_context(ll, ic);
766 return dm_btree_remove(info: &ll->ref_count_info, root: ll->ref_count_root,
767 keys: &b, new_root: &ll->ref_count_root);
768}
769
770static int __sm_ll_dec_overflow(struct ll_disk *ll, dm_block_t b,
771 struct inc_context *ic, uint32_t *old_rc)
772{
773 int r;
774 int index = -1;
775 struct btree_node *n;
776 __le32 *v_ptr;
777 uint32_t rc;
778
779 reset_inc_context(ll, ic);
780 r = btree_get_overwrite_leaf(info: &ll->ref_count_info, root: ll->ref_count_root,
781 key: b, index: &index, new_root: &ll->ref_count_root, leaf: &ic->overflow_leaf);
782 if (r < 0)
783 return r;
784
785 n = dm_block_data(b: ic->overflow_leaf);
786
787 if (!contains_key(n, key: b, index)) {
788 DMERR("overflow btree is missing an entry");
789 return -EINVAL;
790 }
791
792 v_ptr = value_ptr(n, index);
793 rc = le32_to_cpu(*v_ptr);
794 *old_rc = rc;
795
796 if (rc == 3)
797 return __sm_ll_del_overflow(ll, b, ic);
798
799 rc--;
800 *v_ptr = cpu_to_le32(rc);
801 return 0;
802}
803
804static int sm_ll_dec_overflow(struct ll_disk *ll, dm_block_t b,
805 struct inc_context *ic, uint32_t *old_rc)
806{
807 /*
808 * Do we already have the correct overflow leaf?
809 */
810 if (ic->overflow_leaf) {
811 int index;
812 struct btree_node *n;
813 __le32 *v_ptr;
814 uint32_t rc;
815
816 n = dm_block_data(b: ic->overflow_leaf);
817 index = lower_bound(n, key: b);
818 if (contains_key(n, key: b, index)) {
819 v_ptr = value_ptr(n, index);
820 rc = le32_to_cpu(*v_ptr);
821 *old_rc = rc;
822
823 if (rc > 3) {
824 rc--;
825 *v_ptr = cpu_to_le32(rc);
826 return 0;
827 } else {
828 return __sm_ll_del_overflow(ll, b, ic);
829 }
830
831 }
832 }
833
834 return __sm_ll_dec_overflow(ll, b, ic, old_rc);
835}
836
837/*
838 * Loops round incrementing entries in a single bitmap.
839 */
840static inline int sm_ll_dec_bitmap(struct ll_disk *ll, dm_block_t b,
841 uint32_t bit, uint32_t bit_end,
842 struct inc_context *ic,
843 int32_t *nr_allocations, dm_block_t *new_b)
844{
845 int r;
846 uint32_t old;
847
848 for (; bit != bit_end; bit++, b++) {
849 /*
850 * We only need to drop the bitmap if we need to find a new btree
851 * leaf for the overflow. So if it was dropped last iteration,
852 * we now re-get it.
853 */
854 r = ensure_bitmap(ll, ic);
855 if (r)
856 return r;
857
858 old = sm_lookup_bitmap(addr: ic->bitmap, b: bit);
859 switch (old) {
860 case 0:
861 DMERR("unable to decrement block");
862 return -EINVAL;
863
864 case 1:
865 /* dec bitmap */
866 sm_set_bitmap(addr: ic->bitmap, b: bit, val: 0);
867 (*nr_allocations)--;
868 ll->nr_allocated--;
869 le32_add_cpu(var: &ic->ie_disk.nr_free, val: 1);
870 ic->ie_disk.none_free_before =
871 cpu_to_le32(min(le32_to_cpu(ic->ie_disk.none_free_before), bit));
872 break;
873
874 case 2:
875 /* dec bitmap and insert into overflow */
876 sm_set_bitmap(addr: ic->bitmap, b: bit, val: 1);
877 break;
878
879 case 3:
880 r = sm_ll_dec_overflow(ll, b, ic, old_rc: &old);
881 if (r < 0)
882 return r;
883
884 if (old == 3) {
885 r = ensure_bitmap(ll, ic);
886 if (r)
887 return r;
888
889 sm_set_bitmap(addr: ic->bitmap, b: bit, val: 2);
890 }
891 break;
892 }
893 }
894
895 *new_b = b;
896 return 0;
897}
898
899static int __sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e,
900 int32_t *nr_allocations, dm_block_t *new_b)
901{
902 int r;
903 uint32_t bit, bit_end;
904 struct inc_context ic;
905 dm_block_t index = b;
906
907 init_inc_context(ic: &ic);
908
909 bit = do_div(index, ll->entries_per_block);
910 r = ll->load_ie(ll, index, &ic.ie_disk);
911 if (r < 0)
912 return r;
913
914 r = shadow_bitmap(ll, ic: &ic);
915 if (r)
916 return r;
917
918 bit_end = min(bit + (e - b), (dm_block_t) ll->entries_per_block);
919 r = sm_ll_dec_bitmap(ll, b, bit, bit_end, ic: &ic, nr_allocations, new_b);
920 exit_inc_context(ll, ic: &ic);
921
922 if (r)
923 return r;
924
925 return ll->save_ie(ll, index, &ic.ie_disk);
926}
927
928int sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e,
929 int32_t *nr_allocations)
930{
931 *nr_allocations = 0;
932 while (b != e) {
933 int r = __sm_ll_dec(ll, b, e, nr_allocations, new_b: &b);
934
935 if (r)
936 return r;
937 }
938
939 return 0;
940}
941
942/*----------------------------------------------------------------*/
943
944int sm_ll_commit(struct ll_disk *ll)
945{
946 int r = 0;
947
948 if (ll->bitmap_index_changed) {
949 r = ll->commit(ll);
950 if (!r)
951 ll->bitmap_index_changed = false;
952 }
953
954 return r;
955}
956
957/*----------------------------------------------------------------*/
958
959static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
960 struct disk_index_entry *ie)
961{
962 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
963 return 0;
964}
965
966static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
967 struct disk_index_entry *ie)
968{
969 ll->bitmap_index_changed = true;
970 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
971 return 0;
972}
973
974static int metadata_ll_init_index(struct ll_disk *ll)
975{
976 int r;
977 struct dm_block *b;
978
979 r = dm_tm_new_block(tm: ll->tm, v: &index_validator, result: &b);
980 if (r < 0)
981 return r;
982
983 ll->bitmap_root = dm_block_location(b);
984
985 dm_tm_unlock(tm: ll->tm, b);
986
987 return 0;
988}
989
990static int metadata_ll_open(struct ll_disk *ll)
991{
992 int r;
993 struct dm_block *block;
994
995 r = dm_tm_read_lock(tm: ll->tm, b: ll->bitmap_root,
996 v: &index_validator, result: &block);
997 if (r)
998 return r;
999
1000 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
1001 dm_tm_unlock(tm: ll->tm, b: block);
1002
1003 return 0;
1004}
1005
1006static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
1007{
1008 return MAX_METADATA_BITMAPS;
1009}
1010
1011static int metadata_ll_commit(struct ll_disk *ll)
1012{
1013 int r, inc;
1014 struct dm_block *b;
1015
1016 r = dm_tm_shadow_block(tm: ll->tm, orig: ll->bitmap_root, v: &index_validator, result: &b, inc_children: &inc);
1017 if (r)
1018 return r;
1019
1020 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
1021 ll->bitmap_root = dm_block_location(b);
1022
1023 dm_tm_unlock(tm: ll->tm, b);
1024
1025 return 0;
1026}
1027
1028int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
1029{
1030 int r;
1031
1032 r = sm_ll_init(ll, tm);
1033 if (r < 0)
1034 return r;
1035
1036 ll->load_ie = metadata_ll_load_ie;
1037 ll->save_ie = metadata_ll_save_ie;
1038 ll->init_index = metadata_ll_init_index;
1039 ll->open_index = metadata_ll_open;
1040 ll->max_entries = metadata_ll_max_entries;
1041 ll->commit = metadata_ll_commit;
1042
1043 ll->nr_blocks = 0;
1044 ll->nr_allocated = 0;
1045
1046 r = ll->init_index(ll);
1047 if (r < 0)
1048 return r;
1049
1050 r = dm_btree_empty(info: &ll->ref_count_info, root: &ll->ref_count_root);
1051 if (r < 0)
1052 return r;
1053
1054 return 0;
1055}
1056
1057int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
1058 void *root_le, size_t len)
1059{
1060 int r;
1061 struct disk_sm_root smr;
1062
1063 if (len < sizeof(struct disk_sm_root)) {
1064 DMERR("sm_metadata root too small");
1065 return -ENOMEM;
1066 }
1067
1068 /*
1069 * We don't know the alignment of the root_le buffer, so need to
1070 * copy into a new structure.
1071 */
1072 memcpy(&smr, root_le, sizeof(smr));
1073
1074 r = sm_ll_init(ll, tm);
1075 if (r < 0)
1076 return r;
1077
1078 ll->load_ie = metadata_ll_load_ie;
1079 ll->save_ie = metadata_ll_save_ie;
1080 ll->init_index = metadata_ll_init_index;
1081 ll->open_index = metadata_ll_open;
1082 ll->max_entries = metadata_ll_max_entries;
1083 ll->commit = metadata_ll_commit;
1084
1085 ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
1086 ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
1087 ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
1088 ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
1089
1090 return ll->open_index(ll);
1091}
1092
1093/*----------------------------------------------------------------*/
1094
1095static inline int ie_cache_writeback(struct ll_disk *ll, struct ie_cache *iec)
1096{
1097 iec->dirty = false;
1098 __dm_bless_for_disk(iec->ie);
1099 return dm_btree_insert(info: &ll->bitmap_info, root: ll->bitmap_root,
1100 keys: &iec->index, value: &iec->ie, new_root: &ll->bitmap_root);
1101}
1102
1103static inline unsigned int hash_index(dm_block_t index)
1104{
1105 return dm_hash_block(b: index, IE_CACHE_MASK);
1106}
1107
1108static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
1109 struct disk_index_entry *ie)
1110{
1111 int r;
1112 unsigned int h = hash_index(index);
1113 struct ie_cache *iec = ll->ie_cache + h;
1114
1115 if (iec->valid) {
1116 if (iec->index == index) {
1117 memcpy(ie, &iec->ie, sizeof(*ie));
1118 return 0;
1119 }
1120
1121 if (iec->dirty) {
1122 r = ie_cache_writeback(ll, iec);
1123 if (r)
1124 return r;
1125 }
1126 }
1127
1128 r = dm_btree_lookup(info: &ll->bitmap_info, root: ll->bitmap_root, keys: &index, value_le: ie);
1129 if (!r) {
1130 iec->valid = true;
1131 iec->dirty = false;
1132 iec->index = index;
1133 memcpy(&iec->ie, ie, sizeof(*ie));
1134 }
1135
1136 return r;
1137}
1138
1139static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
1140 struct disk_index_entry *ie)
1141{
1142 int r;
1143 unsigned int h = hash_index(index);
1144 struct ie_cache *iec = ll->ie_cache + h;
1145
1146 ll->bitmap_index_changed = true;
1147 if (iec->valid) {
1148 if (iec->index == index) {
1149 memcpy(&iec->ie, ie, sizeof(*ie));
1150 iec->dirty = true;
1151 return 0;
1152 }
1153
1154 if (iec->dirty) {
1155 r = ie_cache_writeback(ll, iec);
1156 if (r)
1157 return r;
1158 }
1159 }
1160
1161 iec->valid = true;
1162 iec->dirty = true;
1163 iec->index = index;
1164 memcpy(&iec->ie, ie, sizeof(*ie));
1165 return 0;
1166}
1167
1168static int disk_ll_init_index(struct ll_disk *ll)
1169{
1170 unsigned int i;
1171
1172 for (i = 0; i < IE_CACHE_SIZE; i++) {
1173 struct ie_cache *iec = ll->ie_cache + i;
1174
1175 iec->valid = false;
1176 iec->dirty = false;
1177 }
1178 return dm_btree_empty(info: &ll->bitmap_info, root: &ll->bitmap_root);
1179}
1180
1181static int disk_ll_open(struct ll_disk *ll)
1182{
1183 return 0;
1184}
1185
1186static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
1187{
1188 return -1ULL;
1189}
1190
1191static int disk_ll_commit(struct ll_disk *ll)
1192{
1193 int r = 0;
1194 unsigned int i;
1195
1196 for (i = 0; i < IE_CACHE_SIZE; i++) {
1197 struct ie_cache *iec = ll->ie_cache + i;
1198
1199 if (iec->valid && iec->dirty)
1200 r = ie_cache_writeback(ll, iec);
1201 }
1202
1203 return r;
1204}
1205
1206int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
1207{
1208 int r;
1209
1210 r = sm_ll_init(ll, tm);
1211 if (r < 0)
1212 return r;
1213
1214 ll->load_ie = disk_ll_load_ie;
1215 ll->save_ie = disk_ll_save_ie;
1216 ll->init_index = disk_ll_init_index;
1217 ll->open_index = disk_ll_open;
1218 ll->max_entries = disk_ll_max_entries;
1219 ll->commit = disk_ll_commit;
1220
1221 ll->nr_blocks = 0;
1222 ll->nr_allocated = 0;
1223
1224 r = ll->init_index(ll);
1225 if (r < 0)
1226 return r;
1227
1228 r = dm_btree_empty(info: &ll->ref_count_info, root: &ll->ref_count_root);
1229 if (r < 0)
1230 return r;
1231
1232 return 0;
1233}
1234
1235int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
1236 void *root_le, size_t len)
1237{
1238 int r;
1239 struct disk_sm_root *smr = root_le;
1240
1241 if (len < sizeof(struct disk_sm_root)) {
1242 DMERR("sm_metadata root too small");
1243 return -ENOMEM;
1244 }
1245
1246 r = sm_ll_init(ll, tm);
1247 if (r < 0)
1248 return r;
1249
1250 ll->load_ie = disk_ll_load_ie;
1251 ll->save_ie = disk_ll_save_ie;
1252 ll->init_index = disk_ll_init_index;
1253 ll->open_index = disk_ll_open;
1254 ll->max_entries = disk_ll_max_entries;
1255 ll->commit = disk_ll_commit;
1256
1257 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
1258 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
1259 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
1260 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
1261
1262 return ll->open_index(ll);
1263}
1264
1265/*----------------------------------------------------------------*/
1266

source code of linux/drivers/md/persistent-data/dm-space-map-common.c