| Joe Thornber | 7a87edf | 2013-03-01 22:45:51 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 Red Hat, Inc. |
| 3 | * |
| 4 | * This file is released under the GPL. |
| 5 | */ |
| 6 | |
| 7 | #include "dm-bitset.h" |
| 8 | #include "dm-transaction-manager.h" |
| 9 | |
| 10 | #include <linux/export.h> |
| 11 | #include <linux/device-mapper.h> |
| 12 | |
| 13 | #define DM_MSG_PREFIX "bitset" |
| 14 | #define BITS_PER_ARRAY_ENTRY 64 |
| 15 | |
| 16 | /*----------------------------------------------------------------*/ |
| 17 | |
| 18 | static struct dm_btree_value_type bitset_bvt = { |
| 19 | .context = NULL, |
| 20 | .size = sizeof(__le64), |
| 21 | .inc = NULL, |
| 22 | .dec = NULL, |
| 23 | .equal = NULL, |
| 24 | }; |
| 25 | |
| 26 | /*----------------------------------------------------------------*/ |
| 27 | |
| 28 | void dm_disk_bitset_init(struct dm_transaction_manager *tm, |
| 29 | struct dm_disk_bitset *info) |
| 30 | { |
| 31 | dm_array_info_init(&info->array_info, tm, &bitset_bvt); |
| 32 | info->current_index_set = false; |
| 33 | } |
| 34 | EXPORT_SYMBOL_GPL(dm_disk_bitset_init); |
| 35 | |
| 36 | int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root) |
| 37 | { |
| 38 | return dm_array_empty(&info->array_info, root); |
| 39 | } |
| 40 | EXPORT_SYMBOL_GPL(dm_bitset_empty); |
| 41 | |
| 42 | int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root, |
| 43 | uint32_t old_nr_entries, uint32_t new_nr_entries, |
| 44 | bool default_value, dm_block_t *new_root) |
| 45 | { |
| 46 | uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY); |
| 47 | uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY); |
| 48 | __le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0); |
| 49 | |
| 50 | __dm_bless_for_disk(&value); |
| 51 | return dm_array_resize(&info->array_info, root, old_blocks, new_blocks, |
| 52 | &value, new_root); |
| 53 | } |
| 54 | EXPORT_SYMBOL_GPL(dm_bitset_resize); |
| 55 | |
| 56 | int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root) |
| 57 | { |
| 58 | return dm_array_del(&info->array_info, root); |
| 59 | } |
| 60 | EXPORT_SYMBOL_GPL(dm_bitset_del); |
| 61 | |
| 62 | int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root, |
| 63 | dm_block_t *new_root) |
| 64 | { |
| 65 | int r; |
| 66 | __le64 value; |
| 67 | |
| 68 | if (!info->current_index_set) |
| 69 | return 0; |
| 70 | |
| 71 | value = cpu_to_le64(info->current_bits); |
| 72 | |
| 73 | __dm_bless_for_disk(&value); |
| 74 | r = dm_array_set_value(&info->array_info, root, info->current_index, |
| 75 | &value, new_root); |
| 76 | if (r) |
| 77 | return r; |
| 78 | |
| 79 | info->current_index_set = false; |
| 80 | return 0; |
| 81 | } |
| 82 | EXPORT_SYMBOL_GPL(dm_bitset_flush); |
| 83 | |
| 84 | static int read_bits(struct dm_disk_bitset *info, dm_block_t root, |
| 85 | uint32_t array_index) |
| 86 | { |
| 87 | int r; |
| 88 | __le64 value; |
| 89 | |
| 90 | r = dm_array_get_value(&info->array_info, root, array_index, &value); |
| 91 | if (r) |
| 92 | return r; |
| 93 | |
| 94 | info->current_bits = le64_to_cpu(value); |
| 95 | info->current_index_set = true; |
| 96 | info->current_index = array_index; |
| 97 | return 0; |
| 98 | } |
| 99 | |
| 100 | static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root, |
| 101 | uint32_t index, dm_block_t *new_root) |
| 102 | { |
| 103 | int r; |
| 104 | unsigned array_index = index / BITS_PER_ARRAY_ENTRY; |
| 105 | |
| 106 | if (info->current_index_set) { |
| 107 | if (info->current_index == array_index) |
| 108 | return 0; |
| 109 | |
| 110 | r = dm_bitset_flush(info, root, new_root); |
| 111 | if (r) |
| 112 | return r; |
| 113 | } |
| 114 | |
| 115 | return read_bits(info, root, array_index); |
| 116 | } |
| 117 | |
| 118 | int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root, |
| 119 | uint32_t index, dm_block_t *new_root) |
| 120 | { |
| 121 | int r; |
| 122 | unsigned b = index % BITS_PER_ARRAY_ENTRY; |
| 123 | |
| 124 | r = get_array_entry(info, root, index, new_root); |
| 125 | if (r) |
| 126 | return r; |
| 127 | |
| 128 | set_bit(b, (unsigned long *) &info->current_bits); |
| 129 | return 0; |
| 130 | } |
| 131 | EXPORT_SYMBOL_GPL(dm_bitset_set_bit); |
| 132 | |
| 133 | int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root, |
| 134 | uint32_t index, dm_block_t *new_root) |
| 135 | { |
| 136 | int r; |
| 137 | unsigned b = index % BITS_PER_ARRAY_ENTRY; |
| 138 | |
| 139 | r = get_array_entry(info, root, index, new_root); |
| 140 | if (r) |
| 141 | return r; |
| 142 | |
| 143 | clear_bit(b, (unsigned long *) &info->current_bits); |
| 144 | return 0; |
| 145 | } |
| 146 | EXPORT_SYMBOL_GPL(dm_bitset_clear_bit); |
| 147 | |
| 148 | int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root, |
| 149 | uint32_t index, dm_block_t *new_root, bool *result) |
| 150 | { |
| 151 | int r; |
| 152 | unsigned b = index % BITS_PER_ARRAY_ENTRY; |
| 153 | |
| 154 | r = get_array_entry(info, root, index, new_root); |
| 155 | if (r) |
| 156 | return r; |
| 157 | |
| 158 | *result = test_bit(b, (unsigned long *) &info->current_bits); |
| 159 | return 0; |
| 160 | } |
| 161 | EXPORT_SYMBOL_GPL(dm_bitset_test_bit); |
| 162 | |
| 163 | /*----------------------------------------------------------------*/ |