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");
248 for (i = old_blocks; i < blocks; i++) {
250 struct disk_index_entry idx;
252 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
255 idx.blocknr = cpu_to_le64(dm_block_location(b));
257 r = dm_tm_unlock(ll->tm, b);
261 idx.nr_free = cpu_to_le32(ll->entries_per_block);
262 idx.none_free_before = 0;
264 r = ll->save_ie(ll, i, &idx);
269 ll->nr_blocks = nr_blocks;
273 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
276 dm_block_t index = b;
277 struct disk_index_entry ie_disk;
278 struct dm_block *blk;
280 b = do_div(index, ll->entries_per_block);
281 r = ll->load_ie(ll, index, &ie_disk);
285 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
286 &dm_sm_bitmap_validator, &blk);
290 *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
292 return dm_tm_unlock(ll->tm, blk);
295 static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
301 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
305 *result = le32_to_cpu(le_rc);
310 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
312 int r = sm_ll_lookup_bitmap(ll, b, result);
320 return sm_ll_lookup_big_ref_count(ll, b, result);
323 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
324 dm_block_t end, dm_block_t *result)
327 struct disk_index_entry ie_disk;
328 dm_block_t i, index_begin = begin;
329 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
334 begin = do_div(index_begin, ll->entries_per_block);
335 end = do_div(end, ll->entries_per_block);
337 for (i = index_begin; i < index_end; i++, begin = 0) {
338 struct dm_block *blk;
342 r = ll->load_ie(ll, i, &ie_disk);
346 if (le32_to_cpu(ie_disk.nr_free) == 0)
349 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
350 &dm_sm_bitmap_validator, &blk);
354 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
356 r = sm_find_free(dm_bitmap_data(blk),
357 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
361 * This might happen because we started searching
362 * part way through the bitmap.
364 dm_tm_unlock(ll->tm, blk);
368 dm_tm_unlock(ll->tm, blk);
372 r = dm_tm_unlock(ll->tm, blk);
376 *result = i * ll->entries_per_block + (dm_block_t) position;
383 static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
384 int (*mutator)(void *context, uint32_t old, uint32_t *new),
385 void *context, enum allocation_event *ev)
388 uint32_t bit, old, ref_count;
390 dm_block_t index = b;
391 struct disk_index_entry ie_disk;
395 bit = do_div(index, ll->entries_per_block);
396 r = ll->load_ie(ll, index, &ie_disk);
400 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
401 &dm_sm_bitmap_validator, &nb, &inc);
403 DMERR("dm_tm_shadow_block() failed");
406 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
408 bm_le = dm_bitmap_data(nb);
409 old = sm_lookup_bitmap(bm_le, bit);
412 r = sm_ll_lookup_big_ref_count(ll, b, &old);
414 dm_tm_unlock(ll->tm, nb);
419 r = mutator(context, old, &ref_count);
421 dm_tm_unlock(ll->tm, nb);
425 if (ref_count <= 2) {
426 sm_set_bitmap(bm_le, bit, ref_count);
428 r = dm_tm_unlock(ll->tm, nb);
433 r = dm_btree_remove(&ll->ref_count_info,
435 &b, &ll->ref_count_root);
441 __le32 le_rc = cpu_to_le32(ref_count);
443 sm_set_bitmap(bm_le, bit, 3);
444 r = dm_tm_unlock(ll->tm, nb);
448 __dm_bless_for_disk(&le_rc);
449 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
450 &b, &le_rc, &ll->ref_count_root);
452 DMERR("ref count insert failed");
457 if (ref_count && !old) {
460 le32_add_cpu(&ie_disk.nr_free, -1);
461 if (le32_to_cpu(ie_disk.none_free_before) == bit)
462 ie_disk.none_free_before = cpu_to_le32(bit + 1);
464 } else if (old && !ref_count) {
467 le32_add_cpu(&ie_disk.nr_free, 1);
468 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
471 return ll->save_ie(ll, index, &ie_disk);
474 static int set_ref_count(void *context, uint32_t old, uint32_t *new)
476 *new = *((uint32_t *) context);
480 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
481 uint32_t ref_count, enum allocation_event *ev)
483 return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
486 static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
492 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
494 return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
497 static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
500 DMERR_LIMIT("unable to decrement a reference count below 0");
508 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
510 return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
513 int sm_ll_commit(struct ll_disk *ll)
517 if (ll->bitmap_index_changed) {
520 ll->bitmap_index_changed = false;
526 /*----------------------------------------------------------------*/
528 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
529 struct disk_index_entry *ie)
531 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
535 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
536 struct disk_index_entry *ie)
538 ll->bitmap_index_changed = true;
539 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
543 static int metadata_ll_init_index(struct ll_disk *ll)
548 r = dm_tm_new_block(ll->tm, &index_validator, &b);
552 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
553 ll->bitmap_root = dm_block_location(b);
555 return dm_tm_unlock(ll->tm, b);
558 static int metadata_ll_open(struct ll_disk *ll)
561 struct dm_block *block;
563 r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
564 &index_validator, &block);
568 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
569 return dm_tm_unlock(ll->tm, block);
572 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
574 return MAX_METADATA_BITMAPS;
577 static int metadata_ll_commit(struct ll_disk *ll)
582 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
586 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
587 ll->bitmap_root = dm_block_location(b);
589 return dm_tm_unlock(ll->tm, b);
592 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
596 r = sm_ll_init(ll, tm);
600 ll->load_ie = metadata_ll_load_ie;
601 ll->save_ie = metadata_ll_save_ie;
602 ll->init_index = metadata_ll_init_index;
603 ll->open_index = metadata_ll_open;
604 ll->max_entries = metadata_ll_max_entries;
605 ll->commit = metadata_ll_commit;
608 ll->nr_allocated = 0;
610 r = ll->init_index(ll);
614 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
621 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
622 void *root_le, size_t len)
625 struct disk_sm_root *smr = root_le;
627 if (len < sizeof(struct disk_sm_root)) {
628 DMERR("sm_metadata root too small");
632 r = sm_ll_init(ll, tm);
636 ll->load_ie = metadata_ll_load_ie;
637 ll->save_ie = metadata_ll_save_ie;
638 ll->init_index = metadata_ll_init_index;
639 ll->open_index = metadata_ll_open;
640 ll->max_entries = metadata_ll_max_entries;
641 ll->commit = metadata_ll_commit;
643 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
644 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
645 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
646 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
648 return ll->open_index(ll);
651 /*----------------------------------------------------------------*/
653 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
654 struct disk_index_entry *ie)
656 return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
659 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
660 struct disk_index_entry *ie)
662 __dm_bless_for_disk(ie);
663 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
664 &index, ie, &ll->bitmap_root);
667 static int disk_ll_init_index(struct ll_disk *ll)
669 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
672 static int disk_ll_open(struct ll_disk *ll)
678 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
683 static int disk_ll_commit(struct ll_disk *ll)
688 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
692 r = sm_ll_init(ll, tm);
696 ll->load_ie = disk_ll_load_ie;
697 ll->save_ie = disk_ll_save_ie;
698 ll->init_index = disk_ll_init_index;
699 ll->open_index = disk_ll_open;
700 ll->max_entries = disk_ll_max_entries;
701 ll->commit = disk_ll_commit;
704 ll->nr_allocated = 0;
706 r = ll->init_index(ll);
710 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
717 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
718 void *root_le, size_t len)
721 struct disk_sm_root *smr = root_le;
723 if (len < sizeof(struct disk_sm_root)) {
724 DMERR("sm_metadata root too small");
728 r = sm_ll_init(ll, tm);
732 ll->load_ie = disk_ll_load_ie;
733 ll->save_ie = disk_ll_save_ie;
734 ll->init_index = disk_ll_init_index;
735 ll->open_index = disk_ll_open;
736 ll->max_entries = disk_ll_max_entries;
737 ll->commit = disk_ll_commit;
739 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
740 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
741 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
742 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
744 return ll->open_index(ll);
747 /*----------------------------------------------------------------*/