#include "dm-bitset.h"
#include "dm-transaction-manager.h"
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "bitset"
#define BITS_PER_ARRAY_ENTRY 64
static struct dm_btree_value_type bitset_bvt = {
.context = NULL,
.size = sizeof(__le64),
.inc = NULL,
.dec = NULL,
.equal = NULL,
};
void dm_disk_bitset_init(struct dm_transaction_manager *tm,
struct dm_disk_bitset *info)
{
dm_array_info_init(&info->array_info, tm, &bitset_bvt);
info->current_index_set = false;
}
EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)
{
return dm_array_empty(&info->array_info, root);
}
EXPORT_SYMBOL_GPL(dm_bitset_empty);
struct packer_context {
bit_value_fn fn;
unsigned int nr_bits;
void *context;
};
static int pack_bits(uint32_t index, void *value, void *context)
{
int r;
struct packer_context *p = context;
unsigned int bit, nr = min(64u, p->nr_bits - (index * 64));
uint64_t word = 0;
bool bv;
for (bit = 0; bit < nr; bit++) {
r = p->fn(index * 64 + bit, &bv, p->context);
if (r)
return r;
if (bv)
set_bit(bit, (unsigned long *) &word);
else
clear_bit(bit, (unsigned long *) &word);
}
*((__le64 *) value) = cpu_to_le64(word);
return 0;
}
int dm_bitset_new(struct dm_disk_bitset *info, dm_block_t *root,
uint32_t size, bit_value_fn fn, void *context)
{
struct packer_context p;
p.fn = fn;
p.nr_bits = size;
p.context = context;
return dm_array_new(&info->array_info, root, dm_div_up(size, 64), pack_bits, &p);
}
EXPORT_SYMBOL_GPL(dm_bitset_new);
int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
uint32_t old_nr_entries, uint32_t new_nr_entries,
bool default_value, dm_block_t *new_root)
{
uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
__le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
__dm_bless_for_disk(&value);
return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
&value, new_root);
}
EXPORT_SYMBOL_GPL(dm_bitset_resize);
int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
{
return dm_array_del(&info->array_info, root);
}
EXPORT_SYMBOL_GPL(dm_bitset_del);
int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
dm_block_t *new_root)
{
int r;
__le64 value;
if (!info->current_index_set || !info->dirty)
return 0;
value = cpu_to_le64(info->current_bits);
__dm_bless_for_disk(&value);
r = dm_array_set_value(&info->array_info, root, info->current_index,
&value, new_root);
if (r)
return r;
info->current_index_set = false;
info->dirty = false;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_flush);
static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
uint32_t array_index)
{
int r;
__le64 value;
r = dm_array_get_value(&info->array_info, root, array_index, &value);
if (r)
return r;
info->current_bits = le64_to_cpu(value);
info->current_index_set = true;
info->current_index = array_index;
info->dirty = false;
return 0;
}
static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root)
{
int r;
unsigned int array_index = index / BITS_PER_ARRAY_ENTRY;
if (info->current_index_set) {
if (info->current_index == array_index)
return 0;
r = dm_bitset_flush(info, root, new_root);
if (r)
return r;
}
return read_bits(info, root, array_index);
}
int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root)
{
int r;
unsigned int b = index % BITS_PER_ARRAY_ENTRY;
r = get_array_entry(info, root, index, new_root);
if (r)
return r;
set_bit(b, (unsigned long *) &info->current_bits);
info->dirty = true;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root)
{
int r;
unsigned int b = index % BITS_PER_ARRAY_ENTRY;
r = get_array_entry(info, root, index, new_root);
if (r)
return r;
clear_bit(b, (unsigned long *) &info->current_bits);
info->dirty = true;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root, bool *result)
{
int r;
unsigned int b = index % BITS_PER_ARRAY_ENTRY;
r = get_array_entry(info, root, index, new_root);
if (r)
return r;
*result = test_bit(b, (unsigned long *) &info->current_bits);
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
static int cursor_next_array_entry(struct dm_bitset_cursor *c)
{
int r;
__le64 *value;
r = dm_array_cursor_next(&c->cursor);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->array_index++;
c->bit_index = 0;
c->current_bits = le64_to_cpu(*value);
return 0;
}
int dm_bitset_cursor_begin(struct dm_disk_bitset *info,
dm_block_t root, uint32_t nr_entries,
struct dm_bitset_cursor *c)
{
int r;
__le64 *value;
if (!nr_entries)
return -ENODATA;
c->info = info;
c->entries_remaining = nr_entries;
r = dm_array_cursor_begin(&info->array_info, root, &c->cursor);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->array_index = 0;
c->bit_index = 0;
c->current_bits = le64_to_cpu(*value);
return r;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin);
void dm_bitset_cursor_end(struct dm_bitset_cursor *c)
{
return dm_array_cursor_end(&c->cursor);
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_end);
int dm_bitset_cursor_next(struct dm_bitset_cursor *c)
{
int r = 0;
if (!c->entries_remaining)
return -ENODATA;
c->entries_remaining--;
if (++c->bit_index > 63)
r = cursor_next_array_entry(c);
return r;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_next);
int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count)
{
int r;
__le64 *value;
uint32_t nr_array_skip;
uint32_t remaining_in_word = 64 - c->bit_index;
if (c->entries_remaining < count)
return -ENODATA;
if (count < remaining_in_word) {
c->bit_index += count;
c->entries_remaining -= count;
return 0;
} else {
c->entries_remaining -= remaining_in_word;
count -= remaining_in_word;
}
nr_array_skip = (count / 64) + 1;
r = dm_array_cursor_skip(&c->cursor, nr_array_skip);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->entries_remaining -= count;
c->array_index += nr_array_skip;
c->bit_index = count & 63;
c->current_bits = le64_to_cpu(*value);
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip);
bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c)
{
return test_bit(c->bit_index, (unsigned long *) &c->current_bits);
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value);