diff options
Diffstat (limited to 'drivers/md/persistent-data/dm-bitset.c')
| -rw-r--r-- | drivers/md/persistent-data/dm-bitset.c | 166 |
1 files changed, 161 insertions, 5 deletions
diff --git a/drivers/md/persistent-data/dm-bitset.c b/drivers/md/persistent-data/dm-bitset.c index cd9a86d4cdf0..00c0a3f186b7 100644 --- a/drivers/md/persistent-data/dm-bitset.c +++ b/drivers/md/persistent-data/dm-bitset.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012 Red Hat, Inc. * @@ -39,6 +40,49 @@ int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *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) @@ -65,7 +109,7 @@ int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root, int r; __le64 value; - if (!info->current_index_set) + if (!info->current_index_set || !info->dirty) return 0; value = cpu_to_le64(info->current_bits); @@ -77,6 +121,8 @@ int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root, return r; info->current_index_set = false; + info->dirty = false; + return 0; } EXPORT_SYMBOL_GPL(dm_bitset_flush); @@ -94,6 +140,8 @@ static int read_bits(struct dm_disk_bitset *info, dm_block_t root, info->current_bits = le64_to_cpu(value); info->current_index_set = true; info->current_index = array_index; + info->dirty = false; + return 0; } @@ -101,7 +149,7 @@ 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 array_index = index / BITS_PER_ARRAY_ENTRY; + unsigned int array_index = index / BITS_PER_ARRAY_ENTRY; if (info->current_index_set) { if (info->current_index == array_index) @@ -119,13 +167,15 @@ 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 b = index % BITS_PER_ARRAY_ENTRY; + 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); @@ -134,13 +184,15 @@ 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 b = index % BITS_PER_ARRAY_ENTRY; + 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); @@ -149,7 +201,7 @@ 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 b = index % BITS_PER_ARRAY_ENTRY; + unsigned int b = index % BITS_PER_ARRAY_ENTRY; r = get_array_entry(info, root, index, new_root); if (r) @@ -160,4 +212,108 @@ int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root, } 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); + /*----------------------------------------------------------------*/ |