Quelle  config.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2023 Red Hat
 */

#include "config.h"

#include "logger.h"
#include "memory-alloc.h"
#include "numeric.h"
#include "string-utils.h"
#include "thread-utils.h"

static const u8 INDEX_CONFIG_MAGIC[] = "ALBIC";
static const u8 INDEX_CONFIG_VERSION_6_02[] = "06.02";
static const u8 INDEX_CONFIG_VERSION_8_02[] = "08.02";

#define DEFAULT_VOLUME_READ_THREADS 2
#define MAX_VOLUME_READ_THREADS 16
#define INDEX_CONFIG_MAGIC_LENGTH (sizeof(INDEX_CONFIG_MAGIC) - 1)
#define INDEX_CONFIG_VERSION_LENGTH ((int)(sizeof(INDEX_CONFIG_VERSION_6_02) - 1))

static bool is_version(const u8 *version, u8 *buffer)
{
 return memcmp(version, buffer, INDEX_CONFIG_VERSION_LENGTH) == 0;
}

static bool are_matching_configurations(struct uds_configuration *saved_config,
     struct index_geometry *saved_geometry,
     struct uds_configuration *user)
{
 struct index_geometry *geometry = user->geometry;
 bool result = true;

 if (saved_geometry->record_pages_per_chapter != geometry->record_pages_per_chapter) {
  vdo_log_error("Record pages per chapter (%u) does not match (%u)",
         saved_geometry->record_pages_per_chapter,
         geometry->record_pages_per_chapter);
  result = false;
 }

 if (saved_geometry->chapters_per_volume != geometry->chapters_per_volume) {
  vdo_log_error("Chapter count (%u) does not match (%u)",
         saved_geometry->chapters_per_volume,
         geometry->chapters_per_volume);
  result = false;
 }

 if (saved_geometry->sparse_chapters_per_volume != geometry->sparse_chapters_per_volume) {
  vdo_log_error("Sparse chapter count (%u) does not match (%u)",
         saved_geometry->sparse_chapters_per_volume,
         geometry->sparse_chapters_per_volume);
  result = false;
 }

 if (saved_config->cache_chapters != user->cache_chapters) {
  vdo_log_error("Cache size (%u) does not match (%u)",
         saved_config->cache_chapters, user->cache_chapters);
  result = false;
 }

 if (saved_config->volume_index_mean_delta != user->volume_index_mean_delta) {
  vdo_log_error("Volume index mean delta (%u) does not match (%u)",
         saved_config->volume_index_mean_delta,
         user->volume_index_mean_delta);
  result = false;
 }

 if (saved_geometry->bytes_per_page != geometry->bytes_per_page) {
  vdo_log_error("Bytes per page value (%zu) does not match (%zu)",
         saved_geometry->bytes_per_page, geometry->bytes_per_page);
  result = false;
 }

 if (saved_config->sparse_sample_rate != user->sparse_sample_rate) {
  vdo_log_error("Sparse sample rate (%u) does not match (%u)",
         saved_config->sparse_sample_rate,
         user->sparse_sample_rate);
  result = false;
 }

 if (saved_config->nonce != user->nonce) {
  vdo_log_error("Nonce (%llu) does not match (%llu)",
         (unsigned long long) saved_config->nonce,
         (unsigned long long) user->nonce);
  result = false;
 }

 return result;
}

/* Read the configuration and validate it against the provided one. */
int uds_validate_config_contents(struct buffered_reader *reader,
     struct uds_configuration *user_config)
{
 int result;
 struct uds_configuration config;
 struct index_geometry geometry;
 u8 version_buffer[INDEX_CONFIG_VERSION_LENGTH];
 u32 bytes_per_page;
 u8 buffer[sizeof(struct uds_configuration_6_02)];
 size_t offset = 0;

 result = uds_verify_buffered_data(reader, INDEX_CONFIG_MAGIC,
       INDEX_CONFIG_MAGIC_LENGTH);
 if (result != UDS_SUCCESS)
  return result;

 result = uds_read_from_buffered_reader(reader, version_buffer,
            INDEX_CONFIG_VERSION_LENGTH);
 if (result != UDS_SUCCESS)
  return vdo_log_error_strerror(result, "cannot read index config version");

 if (!is_version(INDEX_CONFIG_VERSION_6_02, version_buffer) &&
     !is_version(INDEX_CONFIG_VERSION_8_02, version_buffer)) {
  return vdo_log_error_strerror(UDS_CORRUPT_DATA,
           "unsupported configuration version: '%.*s'",
           INDEX_CONFIG_VERSION_LENGTH,
           version_buffer);
 }

 result = uds_read_from_buffered_reader(reader, buffer, sizeof(buffer));
 if (result != UDS_SUCCESS)
  return vdo_log_error_strerror(result, "cannot read config data");

 decode_u32_le(buffer, &offset, &geometry.record_pages_per_chapter);
 decode_u32_le(buffer, &offset, &geometry.chapters_per_volume);
 decode_u32_le(buffer, &offset, &geometry.sparse_chapters_per_volume);
 decode_u32_le(buffer, &offset, &config.cache_chapters);
 offset += sizeof(u32);
 decode_u32_le(buffer, &offset, &config.volume_index_mean_delta);
 decode_u32_le(buffer, &offset, &bytes_per_page);
 geometry.bytes_per_page = bytes_per_page;
 decode_u32_le(buffer, &offset, &config.sparse_sample_rate);
 decode_u64_le(buffer, &offset, &config.nonce);

 result = VDO_ASSERT(offset == sizeof(struct uds_configuration_6_02),
       "%zu bytes read but not decoded",
       sizeof(struct uds_configuration_6_02) - offset);
 if (result != VDO_SUCCESS)
  return UDS_CORRUPT_DATA;

 if (is_version(INDEX_CONFIG_VERSION_6_02, version_buffer)) {
  user_config->geometry->remapped_virtual = 0;
  user_config->geometry->remapped_physical = 0;
 } else {
  u8 remapping[sizeof(u64) + sizeof(u64)];

  result = uds_read_from_buffered_reader(reader, remapping,
             sizeof(remapping));
  if (result != UDS_SUCCESS)
   return vdo_log_error_strerror(result, "cannot read converted config");

  offset = 0;
  decode_u64_le(remapping, &offset,
         &user_config->geometry->remapped_virtual);
  decode_u64_le(remapping, &offset,
         &user_config->geometry->remapped_physical);
 }

 if (!are_matching_configurations(&config, &geometry, user_config)) {
  vdo_log_warning("Supplied configuration does not match save");
  return UDS_NO_INDEX;
 }

 return UDS_SUCCESS;
}

/*
 * Write the configuration to stable storage. If the superblock version is < 4, write the 6.02
 * version; otherwise write the 8.02 version, indicating the configuration is for an index that has
 * been reduced by one chapter.
 */
int uds_write_config_contents(struct buffered_writer *writer,
         struct uds_configuration *config, u32 version)
{
 int result;
 struct index_geometry *geometry = config->geometry;
 u8 buffer[sizeof(struct uds_configuration_8_02)];
 size_t offset = 0;

 result = uds_write_to_buffered_writer(writer, INDEX_CONFIG_MAGIC,
           INDEX_CONFIG_MAGIC_LENGTH);
 if (result != UDS_SUCCESS)
  return result;

 /*
 * If version is < 4, the index has not been reduced by a chapter so it must be written out
 * as version 6.02 so that it is still compatible with older versions of UDS.
 */
 if (version >= 4) {
  result = uds_write_to_buffered_writer(writer, INDEX_CONFIG_VERSION_8_02,
            INDEX_CONFIG_VERSION_LENGTH);
  if (result != UDS_SUCCESS)
   return result;
 } else {
  result = uds_write_to_buffered_writer(writer, INDEX_CONFIG_VERSION_6_02,
            INDEX_CONFIG_VERSION_LENGTH);
  if (result != UDS_SUCCESS)
   return result;
 }

 encode_u32_le(buffer, &offset, geometry->record_pages_per_chapter);
 encode_u32_le(buffer, &offset, geometry->chapters_per_volume);
 encode_u32_le(buffer, &offset, geometry->sparse_chapters_per_volume);
 encode_u32_le(buffer, &offset, config->cache_chapters);
 encode_u32_le(buffer, &offset, 0);
 encode_u32_le(buffer, &offset, config->volume_index_mean_delta);
 encode_u32_le(buffer, &offset, geometry->bytes_per_page);
 encode_u32_le(buffer, &offset, config->sparse_sample_rate);
 encode_u64_le(buffer, &offset, config->nonce);

 result = VDO_ASSERT(offset == sizeof(struct uds_configuration_6_02),
       "%zu bytes encoded, of %zu expected", offset,
       sizeof(struct uds_configuration_6_02));
 if (result != VDO_SUCCESS)
  return result;

 if (version >= 4) {
  encode_u64_le(buffer, &offset, geometry->remapped_virtual);
  encode_u64_le(buffer, &offset, geometry->remapped_physical);
 }

 return uds_write_to_buffered_writer(writer, buffer, offset);
}

/* Compute configuration parameters that depend on memory size. */
static int compute_memory_sizes(uds_memory_config_size_t mem_gb, bool sparse,
    u32 *chapters_per_volume, u32 *record_pages_per_chapter,
    u32 *sparse_chapters_per_volume)
{
 u32 reduced_chapters = 0;
 u32 base_chapters;

 if (mem_gb == UDS_MEMORY_CONFIG_256MB) {
  base_chapters = DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = SMALL_RECORD_PAGES_PER_CHAPTER;
 } else if (mem_gb == UDS_MEMORY_CONFIG_512MB) {
  base_chapters = DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = 2 * SMALL_RECORD_PAGES_PER_CHAPTER;
 } else if (mem_gb == UDS_MEMORY_CONFIG_768MB) {
  base_chapters = DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = 3 * SMALL_RECORD_PAGES_PER_CHAPTER;
 } else if ((mem_gb >= 1) && (mem_gb <= UDS_MEMORY_CONFIG_MAX)) {
  base_chapters = mem_gb * DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = DEFAULT_RECORD_PAGES_PER_CHAPTER;
 } else if (mem_gb == UDS_MEMORY_CONFIG_REDUCED_256MB) {
  reduced_chapters = 1;
  base_chapters = DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = SMALL_RECORD_PAGES_PER_CHAPTER;
 } else if (mem_gb == UDS_MEMORY_CONFIG_REDUCED_512MB) {
  reduced_chapters = 1;
  base_chapters = DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = 2 * SMALL_RECORD_PAGES_PER_CHAPTER;
 } else if (mem_gb == UDS_MEMORY_CONFIG_REDUCED_768MB) {
  reduced_chapters = 1;
  base_chapters = DEFAULT_CHAPTERS_PER_VOLUME;
  *record_pages_per_chapter = 3 * SMALL_RECORD_PAGES_PER_CHAPTER;
 } else if ((mem_gb >= 1 + UDS_MEMORY_CONFIG_REDUCED) &&
     (mem_gb <= UDS_MEMORY_CONFIG_REDUCED_MAX)) {
  reduced_chapters = 1;
  base_chapters = ((mem_gb - UDS_MEMORY_CONFIG_REDUCED) *
     DEFAULT_CHAPTERS_PER_VOLUME);
  *record_pages_per_chapter = DEFAULT_RECORD_PAGES_PER_CHAPTER;
 } else {
  vdo_log_error("received invalid memory size");
  return -EINVAL;
 }

 if (sparse) {
  /* Make 95% of chapters sparse, allowing 10x more records. */
  *sparse_chapters_per_volume = (19 * base_chapters) / 2;
  base_chapters *= 10;
 } else {
  *sparse_chapters_per_volume = 0;
 }

 *chapters_per_volume = base_chapters - reduced_chapters;
 return UDS_SUCCESS;
}

static unsigned int __must_check normalize_zone_count(unsigned int requested)
{
 unsigned int zone_count = requested;

 if (zone_count == 0)
  zone_count = num_online_cpus() / 2;

 if (zone_count < 1)
  zone_count = 1;

 if (zone_count > MAX_ZONES)
  zone_count = MAX_ZONES;

 vdo_log_info("Using %u indexing zone%s for concurrency.",
       zone_count, zone_count == 1 ? "" : "s");
 return zone_count;
}

static unsigned int __must_check normalize_read_threads(unsigned int requested)
{
 unsigned int read_threads = requested;

 if (read_threads < 1)
  read_threads = DEFAULT_VOLUME_READ_THREADS;

 if (read_threads > MAX_VOLUME_READ_THREADS)
  read_threads = MAX_VOLUME_READ_THREADS;

 return read_threads;
}

int uds_make_configuration(const struct uds_parameters *params,
      struct uds_configuration **config_ptr)
{
 struct uds_configuration *config;
 u32 chapters_per_volume = 0;
 u32 record_pages_per_chapter = 0;
 u32 sparse_chapters_per_volume = 0;
 int result;

 result = compute_memory_sizes(params->memory_size, params->sparse,
          &chapters_per_volume, &record_pages_per_chapter,
          &sparse_chapters_per_volume);
 if (result != UDS_SUCCESS)
  return result;

 result = vdo_allocate(1, struct uds_configuration, __func__, &config);
 if (result != VDO_SUCCESS)
  return result;

 result = uds_make_index_geometry(DEFAULT_BYTES_PER_PAGE, record_pages_per_chapter,
      chapters_per_volume, sparse_chapters_per_volume,
      0, 0, &config->geometry);
 if (result != UDS_SUCCESS) {
  uds_free_configuration(config);
  return result;
 }

 config->zone_count = normalize_zone_count(params->zone_count);
 config->read_threads = normalize_read_threads(params->read_threads);

 config->cache_chapters = DEFAULT_CACHE_CHAPTERS;
 config->volume_index_mean_delta = DEFAULT_VOLUME_INDEX_MEAN_DELTA;
 config->sparse_sample_rate = (params->sparse ? DEFAULT_SPARSE_SAMPLE_RATE : 0);
 config->nonce = params->nonce;
 config->bdev = params->bdev;
 config->offset = params->offset;
 config->size = params->size;

 *config_ptr = config;
 return UDS_SUCCESS;
}

void uds_free_configuration(struct uds_configuration *config)
{
 if (config != NULL) {
  uds_free_index_geometry(config->geometry);
  vdo_free(config);
 }
}

void uds_log_configuration(struct uds_configuration *config)
{
 struct index_geometry *geometry = config->geometry;

 vdo_log_debug("Configuration:");
 vdo_log_debug(" Record pages per chapter: %10u", geometry->record_pages_per_chapter);
 vdo_log_debug(" Chapters per volume: %10u", geometry->chapters_per_volume);
 vdo_log_debug(" Sparse chapters per volume: %10u", geometry->sparse_chapters_per_volume);
 vdo_log_debug(" Cache size (chapters): %10u", config->cache_chapters);
 vdo_log_debug(" Volume index mean delta: %10u", config->volume_index_mean_delta);
 vdo_log_debug(" Bytes per page: %10zu", geometry->bytes_per_page);
 vdo_log_debug(" Sparse sample rate: %10u", config->sparse_sample_rate);
 vdo_log_debug(" Nonce: %llu", (unsigned long long) config->nonce);
}