2 * Copyright (C) 2011 Red Hat, Inc.
4 * This file is released under the GPL.
7 #include "dm-space-map-common.h"
8 #include "dm-transaction-manager.h"
10 #include <linux/bitops.h>
11 #include <linux/device-mapper.h>
13 #define DM_MSG_PREFIX "space map common"
15 /*----------------------------------------------------------------*/
20 #define INDEX_CSUM_XOR 160478
22 static void index_prepare_for_write(struct dm_block_validator *v,
26 struct disk_metadata_index *mi_le = dm_block_data(b);
28 mi_le->blocknr = cpu_to_le64(dm_block_location(b));
29 mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
30 block_size - sizeof(__le32),
34 static int index_check(struct dm_block_validator *v,
38 struct disk_metadata_index *mi_le = dm_block_data(b);
41 if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
42 DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
43 le64_to_cpu(mi_le->blocknr), dm_block_location(b));
47 csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
48 block_size - sizeof(__le32),
50 if (csum_disk != mi_le->csum) {
51 DMERR_LIMIT("index_check failed: csum %u != wanted %u",
52 le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
59 static struct dm_block_validator index_validator = {
61 .prepare_for_write = index_prepare_for_write,
65 /*----------------------------------------------------------------*/
70 #define BITMAP_CSUM_XOR 240779
72 static void bitmap_prepare_for_write(struct dm_block_validator *v,
76 struct disk_bitmap_header *disk_header = dm_block_data(b);
78 disk_header->blocknr = cpu_to_le64(dm_block_location(b));
79 disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
80 block_size - sizeof(__le32),
84 static int bitmap_check(struct dm_block_validator *v,
88 struct disk_bitmap_header *disk_header = dm_block_data(b);
91 if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
92 DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
93 le64_to_cpu(disk_header->blocknr), dm_block_location(b));
97 csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
98 block_size - sizeof(__le32),
100 if (csum_disk != disk_header->csum) {
101 DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
102 le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
109 static struct dm_block_validator dm_sm_bitmap_validator = {
111 .prepare_for_write = bitmap_prepare_for_write,
112 .check = bitmap_check
115 /*----------------------------------------------------------------*/
117 #define ENTRIES_PER_WORD 32
118 #define ENTRIES_SHIFT 5
120 static void *dm_bitmap_data(struct dm_block *b)
122 return dm_block_data(b) + sizeof(struct disk_bitmap_header);
125 #define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
127 static unsigned bitmap_word_used(void *addr, unsigned b)
129 __le64 *words_le = addr;
130 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
132 uint64_t bits = le64_to_cpu(*w_le);
133 uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
135 return !(~bits & mask);
138 static unsigned sm_lookup_bitmap(void *addr, unsigned b)
140 __le64 *words_le = addr;
141 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
144 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
145 hi = !!test_bit_le(b, (void *) w_le);
146 lo = !!test_bit_le(b + 1, (void *) w_le);
147 return (hi << 1) | lo;
150 static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
152 __le64 *words_le = addr;
153 __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
155 b = (b & (ENTRIES_PER_WORD - 1)) << 1;
158 __set_bit_le(b, (void *) w_le);
160 __clear_bit_le(b, (void *) w_le);
163 __set_bit_le(b + 1, (void *) w_le);
165 __clear_bit_le(b + 1, (void *) w_le);
168 static int sm_find_free(void *addr, unsigned begin, unsigned end,
171 while (begin < end) {
172 if (!(begin & (ENTRIES_PER_WORD - 1)) &&
173 bitmap_word_used(addr, begin)) {
174 begin += ENTRIES_PER_WORD;
178 if (!sm_lookup_bitmap(addr, begin)) {
189 /*----------------------------------------------------------------*/
191 static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
195 ll->bitmap_info.tm = tm;
196 ll->bitmap_info.levels = 1;
199 * Because the new bitmap blocks are created via a shadow
200 * operation, the old entry has already had its reference count
201 * decremented and we don't need the btree to do any bookkeeping.
203 ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
204 ll->bitmap_info.value_type.inc = NULL;
205 ll->bitmap_info.value_type.dec = NULL;
206 ll->bitmap_info.value_type.equal = NULL;
208 ll->ref_count_info.tm = tm;
209 ll->ref_count_info.levels = 1;
210 ll->ref_count_info.value_type.size = sizeof(uint32_t);
211 ll->ref_count_info.value_type.inc = NULL;
212 ll->ref_count_info.value_type.dec = NULL;
213 ll->ref_count_info.value_type.equal = NULL;
215 ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
217 if (ll->block_size > (1 << 30)) {
218 DMERR("block size too big to hold bitmaps");
222 ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
226 ll->ref_count_root = 0;
227 ll->bitmap_index_changed = false;
232 int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
235 dm_block_t i, nr_blocks, nr_indexes;
236 unsigned old_blocks, blocks;
238 nr_blocks = ll->nr_blocks + extra_blocks;
239 old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
240 blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
242 nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
243 if (nr_indexes > ll->max_entries(ll)) {
244 DMERR("space map too large");
249 * We need to set this before the dm_tm_new_block() call below.
251 ll->nr_blocks = nr_blocks;
252 for (i = old_blocks; i < blocks; i++) {
254 struct disk_index_entry idx;
256 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
260 idx.blocknr = cpu_to_le64(dm_block_location(b));
262 r = dm_tm_unlock(ll->tm, b);
266 idx.nr_free = cpu_to_le32(ll->entries_per_block);
267 idx.none_free_before = 0;
269 r = ll->save_ie(ll, i, &idx);
277 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
280 dm_block_t index = b;
281 struct disk_index_entry ie_disk;
282 struct dm_block *blk;
284 b = do_div(index, ll->entries_per_block);
285 r = ll->load_ie(ll, index, &ie_disk);
289 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
290 &dm_sm_bitmap_validator, &blk);
294 *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
296 return dm_tm_unlock(ll->tm, blk);
299 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
302 int r = sm_ll_lookup_bitmap(ll, b, result);
310 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
314 *result = le32_to_cpu(le_rc);
319 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
320 dm_block_t end, dm_block_t *result)
323 struct disk_index_entry ie_disk;
324 dm_block_t i, index_begin = begin;
325 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
330 begin = do_div(index_begin, ll->entries_per_block);
331 end = do_div(end, ll->entries_per_block);
333 for (i = index_begin; i < index_end; i++, begin = 0) {
334 struct dm_block *blk;
338 r = ll->load_ie(ll, i, &ie_disk);
342 if (le32_to_cpu(ie_disk.nr_free) == 0)
345 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
346 &dm_sm_bitmap_validator, &blk);
350 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
352 r = sm_find_free(dm_bitmap_data(blk),
353 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
357 * This might happen because we started searching
358 * part way through the bitmap.
360 dm_tm_unlock(ll->tm, blk);
364 dm_tm_unlock(ll->tm, blk);
368 r = dm_tm_unlock(ll->tm, blk);
372 *result = i * ll->entries_per_block + (dm_block_t) position;
379 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
380 uint32_t ref_count, enum allocation_event *ev)
385 dm_block_t index = b;
386 struct disk_index_entry ie_disk;
390 bit = do_div(index, ll->entries_per_block);
391 r = ll->load_ie(ll, index, &ie_disk);
395 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
396 &dm_sm_bitmap_validator, &nb, &inc);
398 DMERR("dm_tm_shadow_block() failed");
401 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
403 bm_le = dm_bitmap_data(nb);
404 old = sm_lookup_bitmap(bm_le, bit);
406 if (ref_count <= 2) {
407 sm_set_bitmap(bm_le, bit, ref_count);
409 r = dm_tm_unlock(ll->tm, nb);
414 r = dm_btree_remove(&ll->ref_count_info,
416 &b, &ll->ref_count_root);
422 __le32 le_rc = cpu_to_le32(ref_count);
424 sm_set_bitmap(bm_le, bit, 3);
425 r = dm_tm_unlock(ll->tm, nb);
429 __dm_bless_for_disk(&le_rc);
430 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
431 &b, &le_rc, &ll->ref_count_root);
433 DMERR("ref count insert failed");
438 if (ref_count && !old) {
441 le32_add_cpu(&ie_disk.nr_free, -1);
442 if (le32_to_cpu(ie_disk.none_free_before) == bit)
443 ie_disk.none_free_before = cpu_to_le32(bit + 1);
445 } else if (old && !ref_count) {
448 le32_add_cpu(&ie_disk.nr_free, 1);
449 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
452 return ll->save_ie(ll, index, &ie_disk);
455 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
460 r = sm_ll_lookup(ll, b, &rc);
464 return sm_ll_insert(ll, b, rc + 1, ev);
467 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
472 r = sm_ll_lookup(ll, b, &rc);
479 return sm_ll_insert(ll, b, rc - 1, ev);
482 int sm_ll_commit(struct ll_disk *ll)
486 if (ll->bitmap_index_changed) {
489 ll->bitmap_index_changed = false;
495 /*----------------------------------------------------------------*/
497 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
498 struct disk_index_entry *ie)
500 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
504 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
505 struct disk_index_entry *ie)
507 ll->bitmap_index_changed = true;
508 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
512 static int metadata_ll_init_index(struct ll_disk *ll)
517 r = dm_tm_new_block(ll->tm, &index_validator, &b);
521 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
522 ll->bitmap_root = dm_block_location(b);
524 return dm_tm_unlock(ll->tm, b);
527 static int metadata_ll_open(struct ll_disk *ll)
530 struct dm_block *block;
532 r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
533 &index_validator, &block);
537 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
538 return dm_tm_unlock(ll->tm, block);
541 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
543 return MAX_METADATA_BITMAPS;
546 static int metadata_ll_commit(struct ll_disk *ll)
551 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
555 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
556 ll->bitmap_root = dm_block_location(b);
558 return dm_tm_unlock(ll->tm, b);
561 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
565 r = sm_ll_init(ll, tm);
569 ll->load_ie = metadata_ll_load_ie;
570 ll->save_ie = metadata_ll_save_ie;
571 ll->init_index = metadata_ll_init_index;
572 ll->open_index = metadata_ll_open;
573 ll->max_entries = metadata_ll_max_entries;
574 ll->commit = metadata_ll_commit;
577 ll->nr_allocated = 0;
579 r = ll->init_index(ll);
583 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
590 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
591 void *root_le, size_t len)
594 struct disk_sm_root *smr = root_le;
596 if (len < sizeof(struct disk_sm_root)) {
597 DMERR("sm_metadata root too small");
601 r = sm_ll_init(ll, tm);
605 ll->load_ie = metadata_ll_load_ie;
606 ll->save_ie = metadata_ll_save_ie;
607 ll->init_index = metadata_ll_init_index;
608 ll->open_index = metadata_ll_open;
609 ll->max_entries = metadata_ll_max_entries;
610 ll->commit = metadata_ll_commit;
612 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
613 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
614 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
615 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
617 return ll->open_index(ll);
620 /*----------------------------------------------------------------*/
622 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
623 struct disk_index_entry *ie)
625 return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
628 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
629 struct disk_index_entry *ie)
631 __dm_bless_for_disk(ie);
632 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
633 &index, ie, &ll->bitmap_root);
636 static int disk_ll_init_index(struct ll_disk *ll)
638 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
641 static int disk_ll_open(struct ll_disk *ll)
647 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
652 static int disk_ll_commit(struct ll_disk *ll)
657 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
661 r = sm_ll_init(ll, tm);
665 ll->load_ie = disk_ll_load_ie;
666 ll->save_ie = disk_ll_save_ie;
667 ll->init_index = disk_ll_init_index;
668 ll->open_index = disk_ll_open;
669 ll->max_entries = disk_ll_max_entries;
670 ll->commit = disk_ll_commit;
673 ll->nr_allocated = 0;
675 r = ll->init_index(ll);
679 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
686 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
687 void *root_le, size_t len)
690 struct disk_sm_root *smr = root_le;
692 if (len < sizeof(struct disk_sm_root)) {
693 DMERR("sm_metadata root too small");
697 r = sm_ll_init(ll, tm);
701 ll->load_ie = disk_ll_load_ie;
702 ll->save_ie = disk_ll_save_ie;
703 ll->init_index = disk_ll_init_index;
704 ll->open_index = disk_ll_open;
705 ll->max_entries = disk_ll_max_entries;
706 ll->commit = disk_ll_commit;
708 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
709 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
710 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
711 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
713 return ll->open_index(ll);
716 /*----------------------------------------------------------------*/