172 lines
4.0 KiB
C
172 lines
4.0 KiB
C
/*
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* Copyright (C) 2012 Red Hat, Inc.
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*
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* This file is released under the GPL.
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*/
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#include "dm-bitset.h"
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#include "dm-transaction-manager.h"
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#include <linux/export.h>
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#include <linux/device-mapper.h>
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#define DM_MSG_PREFIX "bitset"
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#define BITS_PER_ARRAY_ENTRY 64
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/*----------------------------------------------------------------*/
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static struct dm_btree_value_type bitset_bvt = {
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.context = NULL,
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.size = sizeof(__le64),
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.inc = NULL,
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.dec = NULL,
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.equal = NULL,
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};
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/*----------------------------------------------------------------*/
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void dm_disk_bitset_init(struct dm_transaction_manager *tm,
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struct dm_disk_bitset *info)
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{
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dm_array_info_init(&info->array_info, tm, &bitset_bvt);
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info->current_index_set = false;
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}
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EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
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int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)
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{
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return dm_array_empty(&info->array_info, root);
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}
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EXPORT_SYMBOL_GPL(dm_bitset_empty);
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int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
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uint32_t old_nr_entries, uint32_t new_nr_entries,
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bool default_value, dm_block_t *new_root)
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{
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uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
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uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
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__le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
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__dm_bless_for_disk(&value);
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return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
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&value, new_root);
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}
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EXPORT_SYMBOL_GPL(dm_bitset_resize);
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int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
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{
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return dm_array_del(&info->array_info, root);
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}
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EXPORT_SYMBOL_GPL(dm_bitset_del);
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int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
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dm_block_t *new_root)
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{
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int r;
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__le64 value;
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if (!info->current_index_set || !info->dirty)
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return 0;
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value = cpu_to_le64(info->current_bits);
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__dm_bless_for_disk(&value);
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r = dm_array_set_value(&info->array_info, root, info->current_index,
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&value, new_root);
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if (r)
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return r;
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info->current_index_set = false;
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info->dirty = false;
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return 0;
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}
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EXPORT_SYMBOL_GPL(dm_bitset_flush);
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static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
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uint32_t array_index)
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{
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int r;
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__le64 value;
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r = dm_array_get_value(&info->array_info, root, array_index, &value);
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if (r)
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return r;
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info->current_bits = le64_to_cpu(value);
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info->current_index_set = true;
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info->current_index = array_index;
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info->dirty = false;
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return 0;
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}
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static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
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uint32_t index, dm_block_t *new_root)
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{
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int r;
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unsigned array_index = index / BITS_PER_ARRAY_ENTRY;
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if (info->current_index_set) {
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if (info->current_index == array_index)
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return 0;
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r = dm_bitset_flush(info, root, new_root);
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if (r)
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return r;
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}
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return read_bits(info, root, array_index);
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}
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int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
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uint32_t index, dm_block_t *new_root)
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{
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int r;
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unsigned b = index % BITS_PER_ARRAY_ENTRY;
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r = get_array_entry(info, root, index, new_root);
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if (r)
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return r;
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set_bit(b, (unsigned long *) &info->current_bits);
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info->dirty = true;
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return 0;
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}
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EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
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int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
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uint32_t index, dm_block_t *new_root)
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{
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int r;
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unsigned b = index % BITS_PER_ARRAY_ENTRY;
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r = get_array_entry(info, root, index, new_root);
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if (r)
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return r;
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clear_bit(b, (unsigned long *) &info->current_bits);
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info->dirty = true;
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return 0;
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}
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EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
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int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
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uint32_t index, dm_block_t *new_root, bool *result)
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{
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int r;
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unsigned b = index % BITS_PER_ARRAY_ENTRY;
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r = get_array_entry(info, root, index, new_root);
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if (r)
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return r;
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*result = test_bit(b, (unsigned long *) &info->current_bits);
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return 0;
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}
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EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
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/*----------------------------------------------------------------*/
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