[linux-2.6-block.git] / drivers / md / persistent-data / dm-bitset.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Red Hat, Inc.
 *
 * This file is released under the GPL.
 */

#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 nr_bits;
	void *context;
};

static int pack_bits(uint32_t index, void *value, void *context)
{
	int r;
	struct packer_context *p = context;
	unsigned 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 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 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 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 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);

/*----------------------------------------------------------------*/
Commit	Line	Data
3bd94003	1	// SPDX-License-Identifier: GPL-2.0-only
7a87edfe JT	2	/*
	3	* Copyright (C) 2012 Red Hat, Inc.
	4	*
	5	* This file is released under the GPL.
	6	*/
	7
	8	#include "dm-bitset.h"
	9	#include "dm-transaction-manager.h"
	10
	11	#include <linux/export.h>
	12	#include <linux/device-mapper.h>
	13
	14	#define DM_MSG_PREFIX "bitset"
	15	#define BITS_PER_ARRAY_ENTRY 64
	16
	17	/----------------------------------------------------------------/
	18
	19	static struct dm_btree_value_type bitset_bvt = {
	20	.context = NULL,
	21	.size = sizeof(__le64),
	22	.inc = NULL,
	23	.dec = NULL,
	24	.equal = NULL,
	25	};
	26
	27	/----------------------------------------------------------------/
	28
	29	void dm_disk_bitset_init(struct dm_transaction_manager *tm,
	30	struct dm_disk_bitset *info)
	31	{
	32	dm_array_info_init(&info->array_info, tm, &bitset_bvt);
	33	info->current_index_set = false;
	34	}
	35	EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
	36
	37	int dm_bitset_empty(struct dm_disk_bitset info, dm_block_t root)
	38	{
	39	return dm_array_empty(&info->array_info, root);
	40	}
	41	EXPORT_SYMBOL_GPL(dm_bitset_empty);
	42
2151249e JT	43	struct packer_context {
	44	bit_value_fn fn;
	45	unsigned nr_bits;
	46	void *context;
	47	};
	48
	49	static int pack_bits(uint32_t index, void value, void context)
	50	{
	51	int r;
	52	struct packer_context *p = context;
	53	unsigned bit, nr = min(64u, p->nr_bits - (index * 64));
	54	uint64_t word = 0;
	55	bool bv;
	56
	57	for (bit = 0; bit < nr; bit++) {
	58	r = p->fn(index * 64 + bit, &bv, p->context);
	59	if (r)
	60	return r;
	61
	62	if (bv)
	63	set_bit(bit, (unsigned long *) &word);
	64	else
	65	clear_bit(bit, (unsigned long *) &word);
	66	}
	67
	68	((__le64 ) value) = cpu_to_le64(word);
	69
	70	return 0;
	71	}
	72
	73	int dm_bitset_new(struct dm_disk_bitset info, dm_block_t root,
	74	uint32_t size, bit_value_fn fn, void *context)
	75	{
	76	struct packer_context p;
	77	p.fn = fn;
	78	p.nr_bits = size;
	79	p.context = context;
	80
	81	return dm_array_new(&info->array_info, root, dm_div_up(size, 64), pack_bits, &p);
	82	}
	83	EXPORT_SYMBOL_GPL(dm_bitset_new);
	84
7a87edfe JT	85	int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
	86	uint32_t old_nr_entries, uint32_t new_nr_entries,
	87	bool default_value, dm_block_t *new_root)
	88	{
	89	uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
	90	uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
	91	__le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
	92
	93	__dm_bless_for_disk(&value);
	94	return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
	95	&value, new_root);
	96	}
	97	EXPORT_SYMBOL_GPL(dm_bitset_resize);
	98
	99	int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
	100	{
	101	return dm_array_del(&info->array_info, root);
	102	}
	103	EXPORT_SYMBOL_GPL(dm_bitset_del);
	104
	105	int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
	106	dm_block_t *new_root)
	107	{
	108	int r;
	109	__le64 value;
	110
428e4698	111	if (!info->current_index_set \|\| !info->dirty)
7a87edfe JT	112	return 0;
	113
	114	value = cpu_to_le64(info->current_bits);
	115
	116	__dm_bless_for_disk(&value);
	117	r = dm_array_set_value(&info->array_info, root, info->current_index,
	118	&value, new_root);
	119	if (r)
	120	return r;
	121
	122	info->current_index_set = false;
428e4698 JT	123	info->dirty = false;
428e4698 JT	124
7a87edfe JT	125	return 0;
	126	}
	127	EXPORT_SYMBOL_GPL(dm_bitset_flush);
	128
	129	static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
	130	uint32_t array_index)
	131	{
	132	int r;
	133	__le64 value;
	134
	135	r = dm_array_get_value(&info->array_info, root, array_index, &value);
	136	if (r)
	137	return r;
	138
	139	info->current_bits = le64_to_cpu(value);
	140	info->current_index_set = true;
	141	info->current_index = array_index;
428e4698 JT	142	info->dirty = false;
428e4698 JT	143
7a87edfe JT	144	return 0;
	145	}
	146
	147	static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
	148	uint32_t index, dm_block_t *new_root)
	149	{
	150	int r;
	151	unsigned array_index = index / BITS_PER_ARRAY_ENTRY;
	152
	153	if (info->current_index_set) {
	154	if (info->current_index == array_index)
	155	return 0;
	156
	157	r = dm_bitset_flush(info, root, new_root);
	158	if (r)
	159	return r;
	160	}
	161
	162	return read_bits(info, root, array_index);
	163	}
	164
	165	int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
	166	uint32_t index, dm_block_t *new_root)
	167	{
	168	int r;
	169	unsigned b = index % BITS_PER_ARRAY_ENTRY;
	170
	171	r = get_array_entry(info, root, index, new_root);
	172	if (r)
	173	return r;
	174
	175	set_bit(b, (unsigned long *) &info->current_bits);
428e4698 JT	176	info->dirty = true;
428e4698 JT	177
7a87edfe JT	178	return 0;
	179	}
	180	EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
	181
	182	int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
	183	uint32_t index, dm_block_t *new_root)
	184	{
	185	int r;
	186	unsigned b = index % BITS_PER_ARRAY_ENTRY;
	187
	188	r = get_array_entry(info, root, index, new_root);
	189	if (r)
	190	return r;
	191
	192	clear_bit(b, (unsigned long *) &info->current_bits);
428e4698 JT	193	info->dirty = true;
428e4698 JT	194
7a87edfe JT	195	return 0;
	196	}
	197	EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
	198
	199	int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
	200	uint32_t index, dm_block_t new_root, bool result)
	201	{
	202	int r;
	203	unsigned b = index % BITS_PER_ARRAY_ENTRY;
	204
	205	r = get_array_entry(info, root, index, new_root);
	206	if (r)
	207	return r;
	208
	209	result = test_bit(b, (unsigned long ) &info->current_bits);
	210	return 0;
	211	}
	212	EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
	213
6fe28dbf JT	214	static int cursor_next_array_entry(struct dm_bitset_cursor *c)
	215	{
	216	int r;
	217	__le64 *value;
	218
	219	r = dm_array_cursor_next(&c->cursor);
	220	if (r)
	221	return r;
	222
	223	dm_array_cursor_get_value(&c->cursor, (void **) &value);
	224	c->array_index++;
	225	c->bit_index = 0;
	226	c->current_bits = le64_to_cpu(*value);
	227	return 0;
	228	}
	229
	230	int dm_bitset_cursor_begin(struct dm_disk_bitset *info,
	231	dm_block_t root, uint32_t nr_entries,
	232	struct dm_bitset_cursor *c)
	233	{
	234	int r;
	235	__le64 *value;
	236
	237	if (!nr_entries)
	238	return -ENODATA;
	239
	240	c->info = info;
	241	c->entries_remaining = nr_entries;
	242
	243	r = dm_array_cursor_begin(&info->array_info, root, &c->cursor);
	244	if (r)
	245	return r;
	246
	247	dm_array_cursor_get_value(&c->cursor, (void **) &value);
	248	c->array_index = 0;
	249	c->bit_index = 0;
	250	c->current_bits = le64_to_cpu(*value);
	251
	252	return r;
	253	}
	254	EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin);
	255
	256	void dm_bitset_cursor_end(struct dm_bitset_cursor *c)
	257	{
	258	return dm_array_cursor_end(&c->cursor);
	259	}
	260	EXPORT_SYMBOL_GPL(dm_bitset_cursor_end);
	261
	262	int dm_bitset_cursor_next(struct dm_bitset_cursor *c)
	263	{
	264	int r = 0;
	265
	266	if (!c->entries_remaining)
	267	return -ENODATA;
	268
	269	c->entries_remaining--;
	270	if (++c->bit_index > 63)
	271	r = cursor_next_array_entry(c);
	272
	273	return r;
	274	}
	275	EXPORT_SYMBOL_GPL(dm_bitset_cursor_next);
	276
9b696229 JT	277	int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count)
	278	{
	279	int r;
	280	__le64 *value;
	281	uint32_t nr_array_skip;
	282	uint32_t remaining_in_word = 64 - c->bit_index;
	283
	284	if (c->entries_remaining < count)
	285	return -ENODATA;
	286
	287	if (count < remaining_in_word) {
	288	c->bit_index += count;
	289	c->entries_remaining -= count;
	290	return 0;
	291
	292	} else {
	293	c->entries_remaining -= remaining_in_word;
	294	count -= remaining_in_word;
	295	}
	296
	297	nr_array_skip = (count / 64) + 1;
	298	r = dm_array_cursor_skip(&c->cursor, nr_array_skip);
	299	if (r)
	300	return r;
	301
	302	dm_array_cursor_get_value(&c->cursor, (void **) &value);
	303	c->entries_remaining -= count;
	304	c->array_index += nr_array_skip;
	305	c->bit_index = count & 63;
	306	c->current_bits = le64_to_cpu(*value);
	307
	308	return 0;
	309	}
	310	EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip);
	311
6fe28dbf JT	312	bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c)
	313	{
	314	return test_bit(c->bit_index, (unsigned long *) &c->current_bits);
	315	}
	316	EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value);
	317
7a87edfe	318	/----------------------------------------------------------------/