/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-space-map-common.h"
#include "dm-transaction-manager.h"
#include <linux/bitops.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "space map common"
/*----------------------------------------------------------------*/
/*
* Index validator.
*/
#define INDEX_CSUM_XOR 160478
static void index_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_metadata_index *mi_le = dm_block_data(b);
mi_le->blocknr = cpu_to_le64(dm_block_location(b));
mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
block_size - sizeof(__le32),
INDEX_CSUM_XOR));
}
static int index_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_metadata_index *mi_le = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
DMERR("index_check failed blocknr %llu wanted %llu",
le64_to_cpu(mi_le->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
block_size - sizeof(__le32),
INDEX_CSUM_XOR));
if (csum_disk != mi_le->csum) {
DMERR("index_check failed csum %u wanted %u",
le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator index_validator = {
.name = "index",
.prepare_for_write = index_prepare_for_write,
.check = index_check
};
/*----------------------------------------------------------------*/
/*
* Bitmap validator
*/
#define BITMAP_CSUM_XOR 240779
static void bitmap_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_bitmap_header *disk_header = dm_block_data(b);
disk_header->blocknr = cpu_to_le64(dm_block_location(b));
disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
block_size - sizeof(__le32),
BITMAP_CSUM_XOR));
}
static int bitmap_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_bitmap_header *disk_header = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
DMERR("bitmap check failed blocknr %llu wanted %llu",
le64_to_cpu(disk_header->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
block_size - sizeof(__le32),
BITMAP_CSUM_XOR));
if (csum_disk != disk_header->csum) {
DMERR("bitmap check failed csum %u wanted %u",
le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator dm_sm_bitmap_validator = {
.name = "sm_bitmap",
.prepare_for_write = bitmap_prepare_for_write,
.check = bitmap_check
};
/*----------------------------------------------------------------*/
#define ENTRIES_PER_WORD 32
#define ENTRIES_SHIFT 5
static void *dm_bitmap_data(struct dm_block *b)
{
return dm_block_data(b) + sizeof(struct disk_bitmap_header);
}
#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
static unsigned bitmap_word_used(void *addr, unsigned b)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
uint64_t bits = le64_to_cpu(*w_le);
uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
return !(~bits & mask);
}
static unsigned sm_lookup_bitmap(void *addr, unsigned b)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
unsigned hi, lo;
b = (b & (ENTRIES_PER_WORD - 1)) << 1;
hi = !!test_bit_le(b, (void *) w_le);
lo = !!test_bit_le(b + 1, (void *) w_le);
return (hi << 1) | lo;
}
static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
b = (b & (ENTRIES_PER_WORD - 1)) << 1;
if (val & 2)
__set_bit_le(b, (void *) w_le);
else
__clear_bit_le(b, (void *) w_le);
if (val & 1)
__set_bit_le(b + 1, (void *) w_le);
else
__clear_bit_le(b + 1, (void *) w_le);
}
static int sm_find_free(void *addr, unsigned begin, unsigned end,
unsigned *result)
{
while (begin < end) {
if (!(begin & (ENTRIES_PER_WORD - 1)) &&
bitmap_word_used(addr, begin)) {
begin += ENTRIES_PER_WORD;
continue;
}
if (!sm_lookup_bitmap(addr, begin)) {
*result = begin;
return 0;
}
begin++;
}
return -ENOSPC;
}
/*----------------------------------------------------------------*/
static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
ll->tm = tm;
ll->bitmap_info.tm = tm;
ll->bitmap_info.levels = 1;
/*
* Because the new bitmap blocks are created via a shadow
* operation, the old entry has already had its reference count
* decremented and we don't need the btree to do any bookkeeping.
*/
ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
ll->bitmap_info.value_type.inc = NULL;
ll->bitmap_info.value_type.dec = NULL;
ll->bitmap_info.value_type.equal = NULL;
ll->ref_count_info.tm = tm;
ll->ref_count_info.levels = 1;
ll->ref_count_info.value_type.size = sizeof(uint32_t);
ll->ref_count_info.value_type.inc = NULL;
ll->ref_count_info.value_type.dec = NULL;
ll->ref_count_info.value_type.equal = NULL;
ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
if (ll->block_size > (1 << 30)) {
DMERR("block size too big to hold bitmaps");
return -EINVAL;
}
ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
ENTRIES_PER_BYTE;
ll->nr_blocks = 0;
ll->bitmap_root = 0;
ll->ref_count_root = 0;
return 0;
}
int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
{
int r;
dm_block_t i, nr_blocks, nr_indexes;
unsigned old_blocks, blocks;
nr_blocks = ll->nr_blocks + extra_blocks;
old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
if (nr_indexes > ll->max_entries(ll)) {
DMERR("space map too large");
return -EINVAL;
}
for (i = old_blocks; i < blocks; i++) {
struct dm_block *b;
struct disk_index_entry idx;
r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
if (r < 0)
return r;
idx.blocknr = cpu_to_le64(dm_block_location(b));
r = dm_tm_unlock(ll->tm, b);
if (r < 0)
return r;
idx.nr_free = cpu_to_le32(ll->entries_per_block);
idx.none_free_before = 0;
r = ll->save_ie(ll, i, &idx);
if (r < 0)
return r;
}
ll->nr_blocks = nr_blocks;
return 0;
}
int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
int r;
dm_block_t index = b;
struct disk_index_entry ie_disk;
struct dm_block *blk;
b = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ie_disk);
if (r < 0)
return r;
r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &blk);
if (r < 0)
return r;
*result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
return dm_tm_unlock(ll->tm, blk);
}
int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
__le32 le_rc;
int r = sm_ll_lookup_bitmap(ll, b, result);
if (r)
return r;
if (*result != 3)
return r;
r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
if (r < 0)
return r;
*result = le32_to_cpu(le_rc);
return r;
}
int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
dm_block_t end, dm_block_t *result)
{
int r;
struct disk_index_entry ie_disk;
dm_block_t i, index_begin = begin;
dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
/*
* FIXME: Use shifts
*/
begin = do_div(index_begin, ll->entries_per_block);
end = do_div(end, ll->entries_per_block);
for (i = index_begin; i < index_end; i++, begin = 0) {
struct dm_block *blk;
unsigned position;
uint32_t bit_end;
r = ll->load_ie(ll, i, &ie_disk);
if (r < 0)
return r;
if (le32_to_cpu(ie_disk.nr_free) == 0)
continue;
r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &blk);
if (r < 0)
return r;
bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
r = sm_find_free(dm_bitmap_data(blk),
max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
bit_end, &position);
if (r == -ENOSPC) {
/*
* This might happen because we started searching
* part way through the bitmap.
*/
dm_tm_unlock(ll->tm, blk);
continue;
} else if (r < 0) {
dm_tm_unlock(ll->tm, blk);
return r;
}
r = dm_tm_unlock(ll->tm, blk);
if (r < 0)
return r;
*result = i * ll->entries_per_block + (dm_block_t) position;
return 0;
}
return -ENOSPC;
}
int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
uint32_t ref_count, enum allocation_event *ev)
{
int r;
uint32_t bit, old;
struct dm_block *nb;
dm_block_t index = b;
struct disk_index_entry ie_disk;
void *bm_le;
int inc;
bit = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ie_disk);
if (r < 0)
return r;
r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &nb, &inc);
if (r < 0) {
DMERR("dm_tm_shadow_block() failed");
return r;
}
ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
bm_le = dm_bitmap_data(nb);
old = sm_lookup_bitmap(bm_le, bit);
if (ref_count <= 2) {
sm_set_bitmap(bm_le, bit, ref_count);
r = dm_tm_unlock(ll->tm, nb);
if (r < 0)
return r;
if (old > 2) {
r = dm_btree_remove(&ll->ref_count_info,
ll->ref_count_root,
&b, &ll->ref_count_root);
if (r)
return r;
}
} else {
__le32 le_rc = cpu_to_le32(ref_count);
sm_set_bitmap(bm_le, bit, 3);
r = dm_tm_unlock(ll->tm, nb);
if (r < 0)
return r;
__dm_bless_for_disk(&le_rc);
r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
&b, &le_rc, &ll->ref_count_root);
if (r < 0) {
DMERR("ref count insert failed");
return r;
}
}
if (ref_count && !old) {
*ev = SM_ALLOC;
ll->nr_allocated++;
ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) - 1);
if (le32_to_cpu(ie_disk.none_free_before) == bit)
ie_disk.none_free_before = cpu_to_le32(bit + 1);
} else if (old && !ref_count) {
*ev = SM_FREE;
ll->nr_allocated--;
ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) + 1);
ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
}
return ll->save_ie(ll, index, &ie_disk);
}
int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
{
int r;
uint32_t rc;
r = sm_ll_lookup(ll, b, &rc);
if (r)
return r;
return sm_ll_insert(ll, b, rc + 1, ev);
}
int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
{
int r;
uint32_t rc;
r = sm_ll_lookup(ll, b, &rc);
if (r)
return r;
if (!rc)
return -EINVAL;
return sm_ll_insert(ll, b, rc - 1, ev);
}
int sm_ll_commit(struct ll_disk *ll)
{
return ll->commit(ll);
}
/*----------------------------------------------------------------*/
static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
return 0;
}
static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
return 0;
}
static int metadata_ll_init_index(struct ll_disk *ll)
{
int r;
struct dm_block *b;
r = dm_tm_new_block(ll->tm, &index_validator, &b);
if (r < 0)
return r;
memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
ll->bitmap_root = dm_block_location(b);
return dm_tm_unlock(ll->tm, b);
}
static int metadata_ll_open(struct ll_disk *ll)
{
int r;
struct dm_block *block;
r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
&index_validator, &block);
if (r)
return r;
memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
return dm_tm_unlock(ll->tm, block);
}
static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
{
return MAX_METADATA_BITMAPS;
}
static int metadata_ll_commit(struct ll_disk *ll)
{
int r, inc;
struct dm_block *b;
r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
if (r)
return r;
memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
ll->bitmap_root = dm_block_location(b);
return dm_tm_unlock(ll->tm, b);
}
int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
int r;
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = metadata_ll_load_ie;
ll->save_ie = metadata_ll_save_ie;
ll->init_index = metadata_ll_init_index;
ll->open_index = metadata_ll_open;
ll->max_entries = metadata_ll_max_entries;
ll->commit = metadata_ll_commit;
ll->nr_blocks = 0;
ll->nr_allocated = 0;
r = ll->init_index(ll);
if (r < 0)
return r;
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
if (r < 0)
return r;
return 0;
}
int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct disk_sm_root *smr = root_le;
if (len < sizeof(struct disk_sm_root)) {
DMERR("sm_metadata root too small");
return -ENOMEM;
}
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = metadata_ll_load_ie;
ll->save_ie = metadata_ll_save_ie;
ll->init_index = metadata_ll_init_index;
ll->open_index = metadata_ll_open;
ll->max_entries = metadata_ll_max_entries;
ll->commit = metadata_ll_commit;
ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
return ll->open_index(ll);
}
/*----------------------------------------------------------------*/
static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
}
static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
__dm_bless_for_disk(ie);
return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
&index, ie, &ll->bitmap_root);
}
static int disk_ll_init_index(struct ll_disk *ll)
{
return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
}
static int disk_ll_open(struct ll_disk *ll)
{
/* nothing to do */
return 0;
}
static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
{
return -1ULL;
}
static int disk_ll_commit(struct ll_disk *ll)
{
return 0;
}
int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
int r;
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = disk_ll_load_ie;
ll->save_ie = disk_ll_save_ie;
ll->init_index = disk_ll_init_index;
ll->open_index = disk_ll_open;
ll->max_entries = disk_ll_max_entries;
ll->commit = disk_ll_commit;
ll->nr_blocks = 0;
ll->nr_allocated = 0;
r = ll->init_index(ll);
if (r < 0)
return r;
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
if (r < 0)
return r;
return 0;
}
int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct disk_sm_root *smr = root_le;
if (len < sizeof(struct disk_sm_root)) {
DMERR("sm_metadata root too small");
return -ENOMEM;
}
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = disk_ll_load_ie;
ll->save_ie = disk_ll_save_ie;
ll->init_index = disk_ll_init_index;
ll->open_index = disk_ll_open;
ll->max_entries = disk_ll_max_entries;
ll->commit = disk_ll_commit;
ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
return ll->open_index(ll);
}
/*----------------------------------------------------------------*/
