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("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("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("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("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;
231 int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
234 dm_block_t i, nr_blocks, nr_indexes;
235 unsigned old_blocks, blocks;
237 nr_blocks = ll->nr_blocks + extra_blocks;
238 old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
239 blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
241 nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
242 if (nr_indexes > ll->max_entries(ll)) {
243 DMERR("space map too large");
248 * We need to set this before the dm_tm_new_block() call below.
250 ll->nr_blocks = nr_blocks;
251 for (i = old_blocks; i < blocks; i++) {
253 struct disk_index_entry idx;
255 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
259 idx.blocknr = cpu_to_le64(dm_block_location(b));
261 r = dm_tm_unlock(ll->tm, b);
265 idx.nr_free = cpu_to_le32(ll->entries_per_block);
266 idx.none_free_before = 0;
268 r = ll->save_ie(ll, i, &idx);
276 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
279 dm_block_t index = b;
280 struct disk_index_entry ie_disk;
281 struct dm_block *blk;
283 b = do_div(index, ll->entries_per_block);
284 r = ll->load_ie(ll, index, &ie_disk);
288 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
289 &dm_sm_bitmap_validator, &blk);
293 *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
295 return dm_tm_unlock(ll->tm, blk);
298 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
301 int r = sm_ll_lookup_bitmap(ll, b, result);
309 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
313 *result = le32_to_cpu(le_rc);
318 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
319 dm_block_t end, dm_block_t *result)
322 struct disk_index_entry ie_disk;
323 dm_block_t i, index_begin = begin;
324 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
329 begin = do_div(index_begin, ll->entries_per_block);
330 end = do_div(end, ll->entries_per_block);
332 for (i = index_begin; i < index_end; i++, begin = 0) {
333 struct dm_block *blk;
337 r = ll->load_ie(ll, i, &ie_disk);
341 if (le32_to_cpu(ie_disk.nr_free) == 0)
344 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
345 &dm_sm_bitmap_validator, &blk);
349 bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
351 r = sm_find_free(dm_bitmap_data(blk),
352 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
356 * This might happen because we started searching
357 * part way through the bitmap.
359 dm_tm_unlock(ll->tm, blk);
363 dm_tm_unlock(ll->tm, blk);
367 r = dm_tm_unlock(ll->tm, blk);
371 *result = i * ll->entries_per_block + (dm_block_t) position;
378 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
379 uint32_t ref_count, enum allocation_event *ev)
384 dm_block_t index = b;
385 struct disk_index_entry ie_disk;
389 bit = do_div(index, ll->entries_per_block);
390 r = ll->load_ie(ll, index, &ie_disk);
394 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
395 &dm_sm_bitmap_validator, &nb, &inc);
397 DMERR("dm_tm_shadow_block() failed");
400 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
402 bm_le = dm_bitmap_data(nb);
403 old = sm_lookup_bitmap(bm_le, bit);
405 if (ref_count <= 2) {
406 sm_set_bitmap(bm_le, bit, ref_count);
408 r = dm_tm_unlock(ll->tm, nb);
413 /* FIXME: dm_btree_remove doesn't handle this yet */
415 r = dm_btree_remove(&ll->ref_count_info,
417 &b, &ll->ref_count_root);
424 __le32 le_rc = cpu_to_le32(ref_count);
426 sm_set_bitmap(bm_le, bit, 3);
427 r = dm_tm_unlock(ll->tm, nb);
431 __dm_bless_for_disk(&le_rc);
432 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
433 &b, &le_rc, &ll->ref_count_root);
435 DMERR("ref count insert failed");
440 if (ref_count && !old) {
443 ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) - 1);
444 if (le32_to_cpu(ie_disk.none_free_before) == bit)
445 ie_disk.none_free_before = cpu_to_le32(bit + 1);
447 } else if (old && !ref_count) {
450 ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) + 1);
451 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
454 return ll->save_ie(ll, index, &ie_disk);
457 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
462 r = sm_ll_lookup(ll, b, &rc);
466 return sm_ll_insert(ll, b, rc + 1, ev);
469 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
474 r = sm_ll_lookup(ll, b, &rc);
481 return sm_ll_insert(ll, b, rc - 1, ev);
484 int sm_ll_commit(struct ll_disk *ll)
486 return ll->commit(ll);
489 /*----------------------------------------------------------------*/
491 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
492 struct disk_index_entry *ie)
494 memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
498 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
499 struct disk_index_entry *ie)
501 memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
505 static int metadata_ll_init_index(struct ll_disk *ll)
510 r = dm_tm_new_block(ll->tm, &index_validator, &b);
514 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
515 ll->bitmap_root = dm_block_location(b);
517 return dm_tm_unlock(ll->tm, b);
520 static int metadata_ll_open(struct ll_disk *ll)
523 struct dm_block *block;
525 r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
526 &index_validator, &block);
530 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
531 return dm_tm_unlock(ll->tm, block);
534 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
536 return MAX_METADATA_BITMAPS;
539 static int metadata_ll_commit(struct ll_disk *ll)
544 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
548 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
549 ll->bitmap_root = dm_block_location(b);
551 return dm_tm_unlock(ll->tm, b);
554 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
558 r = sm_ll_init(ll, tm);
562 ll->load_ie = metadata_ll_load_ie;
563 ll->save_ie = metadata_ll_save_ie;
564 ll->init_index = metadata_ll_init_index;
565 ll->open_index = metadata_ll_open;
566 ll->max_entries = metadata_ll_max_entries;
567 ll->commit = metadata_ll_commit;
570 ll->nr_allocated = 0;
572 r = ll->init_index(ll);
576 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
583 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
584 void *root_le, size_t len)
587 struct disk_sm_root *smr = root_le;
589 if (len < sizeof(struct disk_sm_root)) {
590 DMERR("sm_metadata root too small");
594 r = sm_ll_init(ll, tm);
598 ll->load_ie = metadata_ll_load_ie;
599 ll->save_ie = metadata_ll_save_ie;
600 ll->init_index = metadata_ll_init_index;
601 ll->open_index = metadata_ll_open;
602 ll->max_entries = metadata_ll_max_entries;
603 ll->commit = metadata_ll_commit;
605 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
606 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
607 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
608 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
610 return ll->open_index(ll);
613 /*----------------------------------------------------------------*/
615 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
616 struct disk_index_entry *ie)
618 return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
621 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
622 struct disk_index_entry *ie)
624 __dm_bless_for_disk(ie);
625 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
626 &index, ie, &ll->bitmap_root);
629 static int disk_ll_init_index(struct ll_disk *ll)
631 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
634 static int disk_ll_open(struct ll_disk *ll)
640 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
645 static int disk_ll_commit(struct ll_disk *ll)
650 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
654 r = sm_ll_init(ll, tm);
658 ll->load_ie = disk_ll_load_ie;
659 ll->save_ie = disk_ll_save_ie;
660 ll->init_index = disk_ll_init_index;
661 ll->open_index = disk_ll_open;
662 ll->max_entries = disk_ll_max_entries;
663 ll->commit = disk_ll_commit;
666 ll->nr_allocated = 0;
668 r = ll->init_index(ll);
672 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
679 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
680 void *root_le, size_t len)
683 struct disk_sm_root *smr = root_le;
685 if (len < sizeof(struct disk_sm_root)) {
686 DMERR("sm_metadata root too small");
690 r = sm_ll_init(ll, tm);
694 ll->load_ie = disk_ll_load_ie;
695 ll->save_ie = disk_ll_save_ie;
696 ll->init_index = disk_ll_init_index;
697 ll->open_index = disk_ll_open;
698 ll->max_entries = disk_ll_max_entries;
699 ll->commit = disk_ll_commit;
701 ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
702 ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
703 ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
704 ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
706 return ll->open_index(ll);
709 /*----------------------------------------------------------------*/