1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012 Red Hat, Inc.
4 *
5 * This file is released under the GPL.
6 */
7
8 #include "dm-array.h"
9 #include "dm-space-map.h"
10 #include "dm-transaction-manager.h"
11
12 #include <linux/export.h>
13 #include <linux/device-mapper.h>
14
15 #define DM_MSG_PREFIX "array"
16
17 /*----------------------------------------------------------------*/
18
19 /*
20 * The array is implemented as a fully populated btree, which points to
21 * blocks that contain the packed values. This is more space efficient
22 * than just using a btree since we don't store 1 key per value.
23 */
24 struct array_block {
25 __le32 csum;
26 __le32 max_entries;
27 __le32 nr_entries;
28 __le32 value_size;
29 __le64 blocknr; /* Block this node is supposed to live in. */
30 } __packed;
31
32 /*----------------------------------------------------------------*/
33
34 /*
35 * Validator methods. As usual we calculate a checksum, and also write the
36 * block location into the header (paranoia about ssds remapping areas by
37 * mistake).
38 */
39 #define CSUM_XOR 595846735
40
array_block_prepare_for_write(struct dm_block_validator * v,struct dm_block * b,size_t size_of_block)41 static void array_block_prepare_for_write(struct dm_block_validator *v,
42 struct dm_block *b,
43 size_t size_of_block)
44 {
45 struct array_block *bh_le = dm_block_data(b);
46
47 bh_le->blocknr = cpu_to_le64(dm_block_location(b));
48 bh_le->csum = cpu_to_le32(dm_bm_checksum(&bh_le->max_entries,
49 size_of_block - sizeof(__le32),
50 CSUM_XOR));
51 }
52
array_block_check(struct dm_block_validator * v,struct dm_block * b,size_t size_of_block)53 static int array_block_check(struct dm_block_validator *v,
54 struct dm_block *b,
55 size_t size_of_block)
56 {
57 struct array_block *bh_le = dm_block_data(b);
58 __le32 csum_disk;
59
60 if (dm_block_location(b) != le64_to_cpu(bh_le->blocknr)) {
61 DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
62 (unsigned long long) le64_to_cpu(bh_le->blocknr),
63 (unsigned long long) dm_block_location(b));
64 return -ENOTBLK;
65 }
66
67 csum_disk = cpu_to_le32(dm_bm_checksum(&bh_le->max_entries,
68 size_of_block - sizeof(__le32),
69 CSUM_XOR));
70 if (csum_disk != bh_le->csum) {
71 DMERR_LIMIT("%s failed: csum %u != wanted %u", __func__,
72 (unsigned int) le32_to_cpu(csum_disk),
73 (unsigned int) le32_to_cpu(bh_le->csum));
74 return -EILSEQ;
75 }
76
77 return 0;
78 }
79
80 static struct dm_block_validator array_validator = {
81 .name = "array",
82 .prepare_for_write = array_block_prepare_for_write,
83 .check = array_block_check
84 };
85
86 /*----------------------------------------------------------------*/
87
88 /*
89 * Functions for manipulating the array blocks.
90 */
91
92 /*
93 * Returns a pointer to a value within an array block.
94 *
95 * index - The index into _this_ specific block.
96 */
element_at(struct dm_array_info * info,struct array_block * ab,unsigned int index)97 static void *element_at(struct dm_array_info *info, struct array_block *ab,
98 unsigned int index)
99 {
100 unsigned char *entry = (unsigned char *) (ab + 1);
101
102 entry += index * info->value_type.size;
103
104 return entry;
105 }
106
107 /*
108 * Utility function that calls one of the value_type methods on every value
109 * in an array block.
110 */
on_entries(struct dm_array_info * info,struct array_block * ab,void (* fn)(void *,const void *,unsigned int))111 static void on_entries(struct dm_array_info *info, struct array_block *ab,
112 void (*fn)(void *, const void *, unsigned int))
113 {
114 unsigned int nr_entries = le32_to_cpu(ab->nr_entries);
115
116 fn(info->value_type.context, element_at(info, ab, 0), nr_entries);
117 }
118
119 /*
120 * Increment every value in an array block.
121 */
inc_ablock_entries(struct dm_array_info * info,struct array_block * ab)122 static void inc_ablock_entries(struct dm_array_info *info, struct array_block *ab)
123 {
124 struct dm_btree_value_type *vt = &info->value_type;
125
126 if (vt->inc)
127 on_entries(info, ab, vt->inc);
128 }
129
130 /*
131 * Decrement every value in an array block.
132 */
dec_ablock_entries(struct dm_array_info * info,struct array_block * ab)133 static void dec_ablock_entries(struct dm_array_info *info, struct array_block *ab)
134 {
135 struct dm_btree_value_type *vt = &info->value_type;
136
137 if (vt->dec)
138 on_entries(info, ab, vt->dec);
139 }
140
141 /*
142 * Each array block can hold this many values.
143 */
calc_max_entries(size_t value_size,size_t size_of_block)144 static uint32_t calc_max_entries(size_t value_size, size_t size_of_block)
145 {
146 return (size_of_block - sizeof(struct array_block)) / value_size;
147 }
148
149 /*
150 * Allocate a new array block. The caller will need to unlock block.
151 */
alloc_ablock(struct dm_array_info * info,size_t size_of_block,uint32_t max_entries,struct dm_block ** block,struct array_block ** ab)152 static int alloc_ablock(struct dm_array_info *info, size_t size_of_block,
153 uint32_t max_entries,
154 struct dm_block **block, struct array_block **ab)
155 {
156 int r;
157
158 r = dm_tm_new_block(info->btree_info.tm, &array_validator, block);
159 if (r)
160 return r;
161
162 (*ab) = dm_block_data(*block);
163 (*ab)->max_entries = cpu_to_le32(max_entries);
164 (*ab)->nr_entries = cpu_to_le32(0);
165 (*ab)->value_size = cpu_to_le32(info->value_type.size);
166
167 return 0;
168 }
169
170 /*
171 * Pad an array block out with a particular value. Every instance will
172 * cause an increment of the value_type. new_nr must always be more than
173 * the current number of entries.
174 */
fill_ablock(struct dm_array_info * info,struct array_block * ab,const void * value,unsigned int new_nr)175 static void fill_ablock(struct dm_array_info *info, struct array_block *ab,
176 const void *value, unsigned int new_nr)
177 {
178 uint32_t nr_entries, delta, i;
179 struct dm_btree_value_type *vt = &info->value_type;
180
181 BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
182 BUG_ON(new_nr < le32_to_cpu(ab->nr_entries));
183
184 nr_entries = le32_to_cpu(ab->nr_entries);
185 delta = new_nr - nr_entries;
186 if (vt->inc)
187 vt->inc(vt->context, value, delta);
188 for (i = nr_entries; i < new_nr; i++)
189 memcpy(element_at(info, ab, i), value, vt->size);
190 ab->nr_entries = cpu_to_le32(new_nr);
191 }
192
193 /*
194 * Remove some entries from the back of an array block. Every value
195 * removed will be decremented. new_nr must be <= the current number of
196 * entries.
197 */
trim_ablock(struct dm_array_info * info,struct array_block * ab,unsigned int new_nr)198 static void trim_ablock(struct dm_array_info *info, struct array_block *ab,
199 unsigned int new_nr)
200 {
201 uint32_t nr_entries, delta;
202 struct dm_btree_value_type *vt = &info->value_type;
203
204 BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
205 BUG_ON(new_nr > le32_to_cpu(ab->nr_entries));
206
207 nr_entries = le32_to_cpu(ab->nr_entries);
208 delta = nr_entries - new_nr;
209 if (vt->dec)
210 vt->dec(vt->context, element_at(info, ab, new_nr - 1), delta);
211 ab->nr_entries = cpu_to_le32(new_nr);
212 }
213
214 /*
215 * Read locks a block, and coerces it to an array block. The caller must
216 * unlock 'block' when finished.
217 */
get_ablock(struct dm_array_info * info,dm_block_t b,struct dm_block ** block,struct array_block ** ab)218 static int get_ablock(struct dm_array_info *info, dm_block_t b,
219 struct dm_block **block, struct array_block **ab)
220 {
221 int r;
222
223 r = dm_tm_read_lock(info->btree_info.tm, b, &array_validator, block);
224 if (r)
225 return r;
226
227 *ab = dm_block_data(*block);
228 return 0;
229 }
230
231 /*
232 * Unlocks an array block.
233 */
unlock_ablock(struct dm_array_info * info,struct dm_block * block)234 static void unlock_ablock(struct dm_array_info *info, struct dm_block *block)
235 {
236 dm_tm_unlock(info->btree_info.tm, block);
237 }
238
239 /*----------------------------------------------------------------*/
240
241 /*
242 * Btree manipulation.
243 */
244
245 /*
246 * Looks up an array block in the btree, and then read locks it.
247 *
248 * index is the index of the index of the array_block, (ie. the array index
249 * / max_entries).
250 */
lookup_ablock(struct dm_array_info * info,dm_block_t root,unsigned int index,struct dm_block ** block,struct array_block ** ab)251 static int lookup_ablock(struct dm_array_info *info, dm_block_t root,
252 unsigned int index, struct dm_block **block,
253 struct array_block **ab)
254 {
255 int r;
256 uint64_t key = index;
257 __le64 block_le;
258
259 r = dm_btree_lookup(&info->btree_info, root, &key, &block_le);
260 if (r)
261 return r;
262
263 return get_ablock(info, le64_to_cpu(block_le), block, ab);
264 }
265
266 /*
267 * Insert an array block into the btree. The block is _not_ unlocked.
268 */
insert_ablock(struct dm_array_info * info,uint64_t index,struct dm_block * block,dm_block_t * root)269 static int insert_ablock(struct dm_array_info *info, uint64_t index,
270 struct dm_block *block, dm_block_t *root)
271 {
272 __le64 block_le = cpu_to_le64(dm_block_location(block));
273
274 __dm_bless_for_disk(block_le);
275 return dm_btree_insert(&info->btree_info, *root, &index, &block_le, root);
276 }
277
278 /*----------------------------------------------------------------*/
279
__shadow_ablock(struct dm_array_info * info,dm_block_t b,struct dm_block ** block,struct array_block ** ab)280 static int __shadow_ablock(struct dm_array_info *info, dm_block_t b,
281 struct dm_block **block, struct array_block **ab)
282 {
283 int inc;
284 int r = dm_tm_shadow_block(info->btree_info.tm, b,
285 &array_validator, block, &inc);
286 if (r)
287 return r;
288
289 *ab = dm_block_data(*block);
290 if (inc)
291 inc_ablock_entries(info, *ab);
292
293 return 0;
294 }
295
296 /*
297 * The shadow op will often be a noop. Only insert if it really
298 * copied data.
299 */
__reinsert_ablock(struct dm_array_info * info,unsigned int index,struct dm_block * block,dm_block_t b,dm_block_t * root)300 static int __reinsert_ablock(struct dm_array_info *info, unsigned int index,
301 struct dm_block *block, dm_block_t b,
302 dm_block_t *root)
303 {
304 int r = 0;
305
306 if (dm_block_location(block) != b) {
307 /*
308 * dm_tm_shadow_block will have already decremented the old
309 * block, but it is still referenced by the btree. We
310 * increment to stop the insert decrementing it below zero
311 * when overwriting the old value.
312 */
313 dm_tm_inc(info->btree_info.tm, b);
314 r = insert_ablock(info, index, block, root);
315 }
316
317 return r;
318 }
319
320 /*
321 * Looks up an array block in the btree. Then shadows it, and updates the
322 * btree to point to this new shadow. 'root' is an input/output parameter
323 * for both the current root block, and the new one.
324 */
shadow_ablock(struct dm_array_info * info,dm_block_t * root,unsigned int index,struct dm_block ** block,struct array_block ** ab)325 static int shadow_ablock(struct dm_array_info *info, dm_block_t *root,
326 unsigned int index, struct dm_block **block,
327 struct array_block **ab)
328 {
329 int r;
330 uint64_t key = index;
331 dm_block_t b;
332 __le64 block_le;
333
334 r = dm_btree_lookup(&info->btree_info, *root, &key, &block_le);
335 if (r)
336 return r;
337 b = le64_to_cpu(block_le);
338
339 r = __shadow_ablock(info, b, block, ab);
340 if (r)
341 return r;
342
343 return __reinsert_ablock(info, index, *block, b, root);
344 }
345
346 /*
347 * Allocate an new array block, and fill it with some values.
348 */
insert_new_ablock(struct dm_array_info * info,size_t size_of_block,uint32_t max_entries,unsigned int block_index,uint32_t nr,const void * value,dm_block_t * root)349 static int insert_new_ablock(struct dm_array_info *info, size_t size_of_block,
350 uint32_t max_entries,
351 unsigned int block_index, uint32_t nr,
352 const void *value, dm_block_t *root)
353 {
354 int r;
355 struct dm_block *block;
356 struct array_block *ab;
357
358 r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
359 if (r)
360 return r;
361
362 fill_ablock(info, ab, value, nr);
363 r = insert_ablock(info, block_index, block, root);
364 unlock_ablock(info, block);
365
366 return r;
367 }
368
insert_full_ablocks(struct dm_array_info * info,size_t size_of_block,unsigned int begin_block,unsigned int end_block,unsigned int max_entries,const void * value,dm_block_t * root)369 static int insert_full_ablocks(struct dm_array_info *info, size_t size_of_block,
370 unsigned int begin_block, unsigned int end_block,
371 unsigned int max_entries, const void *value,
372 dm_block_t *root)
373 {
374 int r = 0;
375
376 for (; !r && begin_block != end_block; begin_block++)
377 r = insert_new_ablock(info, size_of_block, max_entries, begin_block, max_entries, value, root);
378
379 return r;
380 }
381
382 /*
383 * There are a bunch of functions involved with resizing an array. This
384 * structure holds information that commonly needed by them. Purely here
385 * to reduce parameter count.
386 */
387 struct resize {
388 /*
389 * Describes the array.
390 */
391 struct dm_array_info *info;
392
393 /*
394 * The current root of the array. This gets updated.
395 */
396 dm_block_t root;
397
398 /*
399 * Metadata block size. Used to calculate the nr entries in an
400 * array block.
401 */
402 size_t size_of_block;
403
404 /*
405 * Maximum nr entries in an array block.
406 */
407 unsigned int max_entries;
408
409 /*
410 * nr of completely full blocks in the array.
411 *
412 * 'old' refers to before the resize, 'new' after.
413 */
414 unsigned int old_nr_full_blocks, new_nr_full_blocks;
415
416 /*
417 * Number of entries in the final block. 0 iff only full blocks in
418 * the array.
419 */
420 unsigned int old_nr_entries_in_last_block, new_nr_entries_in_last_block;
421
422 /*
423 * The default value used when growing the array.
424 */
425 const void *value;
426 };
427
428 /*
429 * Removes a consecutive set of array blocks from the btree. The values
430 * in block are decremented as a side effect of the btree remove.
431 *
432 * begin_index - the index of the first array block to remove.
433 * end_index - the one-past-the-end value. ie. this block is not removed.
434 */
drop_blocks(struct resize * resize,unsigned int begin_index,unsigned int end_index)435 static int drop_blocks(struct resize *resize, unsigned int begin_index,
436 unsigned int end_index)
437 {
438 int r;
439
440 while (begin_index != end_index) {
441 uint64_t key = begin_index++;
442
443 r = dm_btree_remove(&resize->info->btree_info, resize->root,
444 &key, &resize->root);
445 if (r)
446 return r;
447 }
448
449 return 0;
450 }
451
452 /*
453 * Calculates how many blocks are needed for the array.
454 */
total_nr_blocks_needed(unsigned int nr_full_blocks,unsigned int nr_entries_in_last_block)455 static unsigned int total_nr_blocks_needed(unsigned int nr_full_blocks,
456 unsigned int nr_entries_in_last_block)
457 {
458 return nr_full_blocks + (nr_entries_in_last_block ? 1 : 0);
459 }
460
461 /*
462 * Shrink an array.
463 */
shrink(struct resize * resize)464 static int shrink(struct resize *resize)
465 {
466 int r;
467 unsigned int begin, end;
468 struct dm_block *block;
469 struct array_block *ab;
470
471 /*
472 * Lose some blocks from the back?
473 */
474 if (resize->new_nr_full_blocks < resize->old_nr_full_blocks) {
475 begin = total_nr_blocks_needed(resize->new_nr_full_blocks,
476 resize->new_nr_entries_in_last_block);
477 end = total_nr_blocks_needed(resize->old_nr_full_blocks,
478 resize->old_nr_entries_in_last_block);
479
480 r = drop_blocks(resize, begin, end);
481 if (r)
482 return r;
483 }
484
485 /*
486 * Trim the new tail block
487 */
488 if (resize->new_nr_entries_in_last_block) {
489 r = shadow_ablock(resize->info, &resize->root,
490 resize->new_nr_full_blocks, &block, &ab);
491 if (r)
492 return r;
493
494 trim_ablock(resize->info, ab, resize->new_nr_entries_in_last_block);
495 unlock_ablock(resize->info, block);
496 }
497
498 return 0;
499 }
500
501 /*
502 * Grow an array.
503 */
grow_extend_tail_block(struct resize * resize,uint32_t new_nr_entries)504 static int grow_extend_tail_block(struct resize *resize, uint32_t new_nr_entries)
505 {
506 int r;
507 struct dm_block *block;
508 struct array_block *ab;
509
510 r = shadow_ablock(resize->info, &resize->root,
511 resize->old_nr_full_blocks, &block, &ab);
512 if (r)
513 return r;
514
515 fill_ablock(resize->info, ab, resize->value, new_nr_entries);
516 unlock_ablock(resize->info, block);
517
518 return r;
519 }
520
grow_add_tail_block(struct resize * resize)521 static int grow_add_tail_block(struct resize *resize)
522 {
523 return insert_new_ablock(resize->info, resize->size_of_block,
524 resize->max_entries,
525 resize->new_nr_full_blocks,
526 resize->new_nr_entries_in_last_block,
527 resize->value, &resize->root);
528 }
529
grow_needs_more_blocks(struct resize * resize)530 static int grow_needs_more_blocks(struct resize *resize)
531 {
532 int r;
533 unsigned int old_nr_blocks = resize->old_nr_full_blocks;
534
535 if (resize->old_nr_entries_in_last_block > 0) {
536 old_nr_blocks++;
537
538 r = grow_extend_tail_block(resize, resize->max_entries);
539 if (r)
540 return r;
541 }
542
543 r = insert_full_ablocks(resize->info, resize->size_of_block,
544 old_nr_blocks,
545 resize->new_nr_full_blocks,
546 resize->max_entries, resize->value,
547 &resize->root);
548 if (r)
549 return r;
550
551 if (resize->new_nr_entries_in_last_block)
552 r = grow_add_tail_block(resize);
553
554 return r;
555 }
556
grow(struct resize * resize)557 static int grow(struct resize *resize)
558 {
559 if (resize->new_nr_full_blocks > resize->old_nr_full_blocks)
560 return grow_needs_more_blocks(resize);
561
562 else if (resize->old_nr_entries_in_last_block)
563 return grow_extend_tail_block(resize, resize->new_nr_entries_in_last_block);
564
565 else
566 return grow_add_tail_block(resize);
567 }
568
569 /*----------------------------------------------------------------*/
570
571 /*
572 * These are the value_type functions for the btree elements, which point
573 * to array blocks.
574 */
block_inc(void * context,const void * value,unsigned int count)575 static void block_inc(void *context, const void *value, unsigned int count)
576 {
577 const __le64 *block_le = value;
578 struct dm_array_info *info = context;
579 unsigned int i;
580
581 for (i = 0; i < count; i++, block_le++)
582 dm_tm_inc(info->btree_info.tm, le64_to_cpu(*block_le));
583 }
584
__block_dec(void * context,const void * value)585 static void __block_dec(void *context, const void *value)
586 {
587 int r;
588 uint64_t b;
589 __le64 block_le;
590 uint32_t ref_count;
591 struct dm_block *block;
592 struct array_block *ab;
593 struct dm_array_info *info = context;
594
595 memcpy(&block_le, value, sizeof(block_le));
596 b = le64_to_cpu(block_le);
597
598 r = dm_tm_ref(info->btree_info.tm, b, &ref_count);
599 if (r) {
600 DMERR_LIMIT("couldn't get reference count for block %llu",
601 (unsigned long long) b);
602 return;
603 }
604
605 if (ref_count == 1) {
606 /*
607 * We're about to drop the last reference to this ablock.
608 * So we need to decrement the ref count of the contents.
609 */
610 r = get_ablock(info, b, &block, &ab);
611 if (r) {
612 DMERR_LIMIT("couldn't get array block %llu",
613 (unsigned long long) b);
614 return;
615 }
616
617 dec_ablock_entries(info, ab);
618 unlock_ablock(info, block);
619 }
620
621 dm_tm_dec(info->btree_info.tm, b);
622 }
623
block_dec(void * context,const void * value,unsigned int count)624 static void block_dec(void *context, const void *value, unsigned int count)
625 {
626 unsigned int i;
627
628 for (i = 0; i < count; i++, value += sizeof(__le64))
629 __block_dec(context, value);
630 }
631
block_equal(void * context,const void * value1,const void * value2)632 static int block_equal(void *context, const void *value1, const void *value2)
633 {
634 return !memcmp(value1, value2, sizeof(__le64));
635 }
636
637 /*----------------------------------------------------------------*/
638
dm_array_info_init(struct dm_array_info * info,struct dm_transaction_manager * tm,struct dm_btree_value_type * vt)639 void dm_array_info_init(struct dm_array_info *info,
640 struct dm_transaction_manager *tm,
641 struct dm_btree_value_type *vt)
642 {
643 struct dm_btree_value_type *bvt = &info->btree_info.value_type;
644
645 memcpy(&info->value_type, vt, sizeof(info->value_type));
646 info->btree_info.tm = tm;
647 info->btree_info.levels = 1;
648
649 bvt->context = info;
650 bvt->size = sizeof(__le64);
651 bvt->inc = block_inc;
652 bvt->dec = block_dec;
653 bvt->equal = block_equal;
654 }
655 EXPORT_SYMBOL_GPL(dm_array_info_init);
656
dm_array_empty(struct dm_array_info * info,dm_block_t * root)657 int dm_array_empty(struct dm_array_info *info, dm_block_t *root)
658 {
659 return dm_btree_empty(&info->btree_info, root);
660 }
661 EXPORT_SYMBOL_GPL(dm_array_empty);
662
array_resize(struct dm_array_info * info,dm_block_t root,uint32_t old_size,uint32_t new_size,const void * value,dm_block_t * new_root)663 static int array_resize(struct dm_array_info *info, dm_block_t root,
664 uint32_t old_size, uint32_t new_size,
665 const void *value, dm_block_t *new_root)
666 {
667 int r;
668 struct resize resize;
669
670 if (old_size == new_size) {
671 *new_root = root;
672 return 0;
673 }
674
675 resize.info = info;
676 resize.root = root;
677 resize.size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
678 resize.max_entries = calc_max_entries(info->value_type.size,
679 resize.size_of_block);
680
681 resize.old_nr_full_blocks = old_size / resize.max_entries;
682 resize.old_nr_entries_in_last_block = old_size % resize.max_entries;
683 resize.new_nr_full_blocks = new_size / resize.max_entries;
684 resize.new_nr_entries_in_last_block = new_size % resize.max_entries;
685 resize.value = value;
686
687 r = ((new_size > old_size) ? grow : shrink)(&resize);
688 if (r)
689 return r;
690
691 *new_root = resize.root;
692 return 0;
693 }
694
dm_array_resize(struct dm_array_info * info,dm_block_t root,uint32_t old_size,uint32_t new_size,const void * value,dm_block_t * new_root)695 int dm_array_resize(struct dm_array_info *info, dm_block_t root,
696 uint32_t old_size, uint32_t new_size,
697 const void *value, dm_block_t *new_root)
698 __dm_written_to_disk(value)
699 {
700 int r = array_resize(info, root, old_size, new_size, value, new_root);
701
702 __dm_unbless_for_disk(value);
703 return r;
704 }
705 EXPORT_SYMBOL_GPL(dm_array_resize);
706
populate_ablock_with_values(struct dm_array_info * info,struct array_block * ab,value_fn fn,void * context,unsigned int base,unsigned int new_nr)707 static int populate_ablock_with_values(struct dm_array_info *info, struct array_block *ab,
708 value_fn fn, void *context,
709 unsigned int base, unsigned int new_nr)
710 {
711 int r;
712 unsigned int i;
713 struct dm_btree_value_type *vt = &info->value_type;
714
715 BUG_ON(le32_to_cpu(ab->nr_entries));
716 BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
717
718 for (i = 0; i < new_nr; i++) {
719 r = fn(base + i, element_at(info, ab, i), context);
720 if (r)
721 return r;
722
723 if (vt->inc)
724 vt->inc(vt->context, element_at(info, ab, i), 1);
725 }
726
727 ab->nr_entries = cpu_to_le32(new_nr);
728 return 0;
729 }
730
dm_array_new(struct dm_array_info * info,dm_block_t * root,uint32_t size,value_fn fn,void * context)731 int dm_array_new(struct dm_array_info *info, dm_block_t *root,
732 uint32_t size, value_fn fn, void *context)
733 {
734 int r;
735 struct dm_block *block;
736 struct array_block *ab;
737 unsigned int block_index, end_block, size_of_block, max_entries;
738
739 r = dm_array_empty(info, root);
740 if (r)
741 return r;
742
743 size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
744 max_entries = calc_max_entries(info->value_type.size, size_of_block);
745 end_block = dm_div_up(size, max_entries);
746
747 for (block_index = 0; block_index != end_block; block_index++) {
748 r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
749 if (r)
750 break;
751
752 r = populate_ablock_with_values(info, ab, fn, context,
753 block_index * max_entries,
754 min(max_entries, size));
755 if (r) {
756 unlock_ablock(info, block);
757 break;
758 }
759
760 r = insert_ablock(info, block_index, block, root);
761 unlock_ablock(info, block);
762 if (r)
763 break;
764
765 size -= max_entries;
766 }
767
768 return r;
769 }
770 EXPORT_SYMBOL_GPL(dm_array_new);
771
dm_array_del(struct dm_array_info * info,dm_block_t root)772 int dm_array_del(struct dm_array_info *info, dm_block_t root)
773 {
774 return dm_btree_del(&info->btree_info, root);
775 }
776 EXPORT_SYMBOL_GPL(dm_array_del);
777
dm_array_get_value(struct dm_array_info * info,dm_block_t root,uint32_t index,void * value_le)778 int dm_array_get_value(struct dm_array_info *info, dm_block_t root,
779 uint32_t index, void *value_le)
780 {
781 int r;
782 struct dm_block *block;
783 struct array_block *ab;
784 size_t size_of_block;
785 unsigned int entry, max_entries;
786
787 size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
788 max_entries = calc_max_entries(info->value_type.size, size_of_block);
789
790 r = lookup_ablock(info, root, index / max_entries, &block, &ab);
791 if (r)
792 return r;
793
794 entry = index % max_entries;
795 if (entry >= le32_to_cpu(ab->nr_entries))
796 r = -ENODATA;
797 else
798 memcpy(value_le, element_at(info, ab, entry),
799 info->value_type.size);
800
801 unlock_ablock(info, block);
802 return r;
803 }
804 EXPORT_SYMBOL_GPL(dm_array_get_value);
805
array_set_value(struct dm_array_info * info,dm_block_t root,uint32_t index,const void * value,dm_block_t * new_root)806 static int array_set_value(struct dm_array_info *info, dm_block_t root,
807 uint32_t index, const void *value, dm_block_t *new_root)
808 {
809 int r;
810 struct dm_block *block;
811 struct array_block *ab;
812 size_t size_of_block;
813 unsigned int max_entries;
814 unsigned int entry;
815 void *old_value;
816 struct dm_btree_value_type *vt = &info->value_type;
817
818 size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
819 max_entries = calc_max_entries(info->value_type.size, size_of_block);
820
821 r = shadow_ablock(info, &root, index / max_entries, &block, &ab);
822 if (r)
823 return r;
824 *new_root = root;
825
826 entry = index % max_entries;
827 if (entry >= le32_to_cpu(ab->nr_entries)) {
828 r = -ENODATA;
829 goto out;
830 }
831
832 old_value = element_at(info, ab, entry);
833 if (vt->dec &&
834 (!vt->equal || !vt->equal(vt->context, old_value, value))) {
835 vt->dec(vt->context, old_value, 1);
836 if (vt->inc)
837 vt->inc(vt->context, value, 1);
838 }
839
840 memcpy(old_value, value, info->value_type.size);
841
842 out:
843 unlock_ablock(info, block);
844 return r;
845 }
846
dm_array_set_value(struct dm_array_info * info,dm_block_t root,uint32_t index,const void * value,dm_block_t * new_root)847 int dm_array_set_value(struct dm_array_info *info, dm_block_t root,
848 uint32_t index, const void *value, dm_block_t *new_root)
849 __dm_written_to_disk(value)
850 {
851 int r;
852
853 r = array_set_value(info, root, index, value, new_root);
854 __dm_unbless_for_disk(value);
855 return r;
856 }
857 EXPORT_SYMBOL_GPL(dm_array_set_value);
858
859 struct walk_info {
860 struct dm_array_info *info;
861 int (*fn)(void *context, uint64_t key, void *leaf);
862 void *context;
863 };
864
walk_ablock(void * context,uint64_t * keys,void * leaf)865 static int walk_ablock(void *context, uint64_t *keys, void *leaf)
866 {
867 struct walk_info *wi = context;
868
869 int r;
870 unsigned int i;
871 __le64 block_le;
872 unsigned int nr_entries, max_entries;
873 struct dm_block *block;
874 struct array_block *ab;
875
876 memcpy(&block_le, leaf, sizeof(block_le));
877 r = get_ablock(wi->info, le64_to_cpu(block_le), &block, &ab);
878 if (r)
879 return r;
880
881 max_entries = le32_to_cpu(ab->max_entries);
882 nr_entries = le32_to_cpu(ab->nr_entries);
883 for (i = 0; i < nr_entries; i++) {
884 r = wi->fn(wi->context, keys[0] * max_entries + i,
885 element_at(wi->info, ab, i));
886
887 if (r)
888 break;
889 }
890
891 unlock_ablock(wi->info, block);
892 return r;
893 }
894
dm_array_walk(struct dm_array_info * info,dm_block_t root,int (* fn)(void *,uint64_t key,void * leaf),void * context)895 int dm_array_walk(struct dm_array_info *info, dm_block_t root,
896 int (*fn)(void *, uint64_t key, void *leaf),
897 void *context)
898 {
899 struct walk_info wi;
900
901 wi.info = info;
902 wi.fn = fn;
903 wi.context = context;
904
905 return dm_btree_walk(&info->btree_info, root, walk_ablock, &wi);
906 }
907 EXPORT_SYMBOL_GPL(dm_array_walk);
908
909 /*----------------------------------------------------------------*/
910
load_ablock(struct dm_array_cursor * c)911 static int load_ablock(struct dm_array_cursor *c)
912 {
913 int r;
914 __le64 value_le;
915 uint64_t key;
916
917 if (c->block)
918 unlock_ablock(c->info, c->block);
919
920 c->block = NULL;
921 c->ab = NULL;
922 c->index = 0;
923
924 r = dm_btree_cursor_get_value(&c->cursor, &key, &value_le);
925 if (r) {
926 DMERR("dm_btree_cursor_get_value failed");
927 dm_btree_cursor_end(&c->cursor);
928
929 } else {
930 r = get_ablock(c->info, le64_to_cpu(value_le), &c->block, &c->ab);
931 if (r) {
932 DMERR("get_ablock failed");
933 dm_btree_cursor_end(&c->cursor);
934 }
935 }
936
937 return r;
938 }
939
dm_array_cursor_begin(struct dm_array_info * info,dm_block_t root,struct dm_array_cursor * c)940 int dm_array_cursor_begin(struct dm_array_info *info, dm_block_t root,
941 struct dm_array_cursor *c)
942 {
943 int r;
944
945 memset(c, 0, sizeof(*c));
946 c->info = info;
947 r = dm_btree_cursor_begin(&info->btree_info, root, true, &c->cursor);
948 if (r) {
949 DMERR("couldn't create btree cursor");
950 return r;
951 }
952
953 return load_ablock(c);
954 }
955 EXPORT_SYMBOL_GPL(dm_array_cursor_begin);
956
dm_array_cursor_end(struct dm_array_cursor * c)957 void dm_array_cursor_end(struct dm_array_cursor *c)
958 {
959 if (c->block) {
960 unlock_ablock(c->info, c->block);
961 dm_btree_cursor_end(&c->cursor);
962 }
963 }
964 EXPORT_SYMBOL_GPL(dm_array_cursor_end);
965
dm_array_cursor_next(struct dm_array_cursor * c)966 int dm_array_cursor_next(struct dm_array_cursor *c)
967 {
968 int r;
969
970 if (!c->block)
971 return -ENODATA;
972
973 c->index++;
974
975 if (c->index >= le32_to_cpu(c->ab->nr_entries)) {
976 r = dm_btree_cursor_next(&c->cursor);
977 if (r)
978 return r;
979
980 r = load_ablock(c);
981 if (r)
982 return r;
983 }
984
985 return 0;
986 }
987 EXPORT_SYMBOL_GPL(dm_array_cursor_next);
988
dm_array_cursor_skip(struct dm_array_cursor * c,uint32_t count)989 int dm_array_cursor_skip(struct dm_array_cursor *c, uint32_t count)
990 {
991 int r;
992
993 do {
994 uint32_t remaining = le32_to_cpu(c->ab->nr_entries) - c->index;
995
996 if (count < remaining) {
997 c->index += count;
998 return 0;
999 }
1000
1001 count -= remaining;
1002 r = dm_array_cursor_next(c);
1003
1004 } while (!r);
1005
1006 return r;
1007 }
1008 EXPORT_SYMBOL_GPL(dm_array_cursor_skip);
1009
dm_array_cursor_get_value(struct dm_array_cursor * c,void ** value_le)1010 void dm_array_cursor_get_value(struct dm_array_cursor *c, void **value_le)
1011 {
1012 *value_le = element_at(c->info, c->ab, c->index);
1013 }
1014 EXPORT_SYMBOL_GPL(dm_array_cursor_get_value);
1015
1016 /*----------------------------------------------------------------*/
1017