diff options
Diffstat (limited to 'drivers/md/dm-vdo/indexer/index-layout.c')
| -rw-r--r-- | drivers/md/dm-vdo/indexer/index-layout.c | 1765 |
1 files changed, 1765 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/indexer/index-layout.c b/drivers/md/dm-vdo/indexer/index-layout.c new file mode 100644 index 000000000..627adc24a --- /dev/null +++ b/drivers/md/dm-vdo/indexer/index-layout.c @@ -0,0 +1,1765 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2023 Red Hat + */ + +#include "index-layout.h" + +#include <linux/random.h> + +#include "logger.h" +#include "memory-alloc.h" +#include "murmurhash3.h" +#include "numeric.h" +#include "time-utils.h" + +#include "config.h" +#include "open-chapter.h" +#include "volume-index.h" + +/* + * The UDS layout on storage media is divided into a number of fixed-size regions, the sizes of + * which are computed when the index is created. Every header and region begins on 4K block + * boundary. Save regions are further sub-divided into regions of their own. + * + * Each region has a kind and an instance number. Some kinds only have one instance and therefore + * use RL_SOLE_INSTANCE (-1) as the instance number. The RL_KIND_INDEX used to use instances to + * represent sub-indices; now, however there is only ever one sub-index and therefore one instance. + * The RL_KIND_VOLUME_INDEX uses instances to record which zone is being saved. + * + * Every region header has a type and version. + * + * +-+-+---------+--------+--------+-+ + * | | | I N D E X 0 101, 0 | | + * |H|C+---------+--------+--------+S| + * |D|f| Volume | Save | Save |e| + * |R|g| Region | Region | Region |a| + * | | | 201, -1 | 202, 0 | 202, 1 |l| + * +-+-+--------+---------+--------+-+ + * + * The header contains the encoded region layout table as well as some index configuration data. + * The sub-index region and its subdivisions are maintained in the same table. + * + * There are two save regions to preserve the old state in case saving the new state is incomplete. + * They are used in alternation. Each save region is further divided into sub-regions. + * + * +-+-----+------+------+-----+-----+ + * |H| IPM | MI | MI | | OC | + * |D| | zone | zone | ... | | + * |R| 301 | 302 | 302 | | 303 | + * | | -1 | 0 | 1 | | -1 | + * +-+-----+------+------+-----+-----+ + * + * The header contains the encoded region layout table as well as index state data for that save. + * Each save also has a unique nonce. + */ + +#define MAGIC_SIZE 32 +#define NONCE_INFO_SIZE 32 +#define MAX_SAVES 2 + +enum region_kind { + RL_KIND_EMPTY = 0, + RL_KIND_HEADER = 1, + RL_KIND_CONFIG = 100, + RL_KIND_INDEX = 101, + RL_KIND_SEAL = 102, + RL_KIND_VOLUME = 201, + RL_KIND_SAVE = 202, + RL_KIND_INDEX_PAGE_MAP = 301, + RL_KIND_VOLUME_INDEX = 302, + RL_KIND_OPEN_CHAPTER = 303, +}; + +/* Some region types are historical and are no longer used. */ +enum region_type { + RH_TYPE_FREE = 0, /* unused */ + RH_TYPE_SUPER = 1, + RH_TYPE_SAVE = 2, + RH_TYPE_CHECKPOINT = 3, /* unused */ + RH_TYPE_UNSAVED = 4, +}; + +#define RL_SOLE_INSTANCE 65535 + +/* + * Super block version 2 is the first released version. + * + * Super block version 3 is the normal version used from RHEL 8.2 onwards. + * + * Super block versions 4 through 6 were incremental development versions and + * are not supported. + * + * Super block version 7 is used for volumes which have been reduced in size by one chapter in + * order to make room to prepend LVM metadata to a volume originally created without lvm. This + * allows the index to retain most its deduplication records. + */ +#define SUPER_VERSION_MINIMUM 3 +#define SUPER_VERSION_CURRENT 3 +#define SUPER_VERSION_MAXIMUM 7 + +static const u8 LAYOUT_MAGIC[MAGIC_SIZE] = "*ALBIREO*SINGLE*FILE*LAYOUT*001*"; +static const u64 REGION_MAGIC = 0x416c6252676e3031; /* 'AlbRgn01' */ + +struct region_header { + u64 magic; + u64 region_blocks; + u16 type; + /* Currently always version 1 */ + u16 version; + u16 region_count; + u16 payload; +}; + +struct layout_region { + u64 start_block; + u64 block_count; + u32 __unused; + u16 kind; + u16 instance; +}; + +struct region_table { + size_t encoded_size; + struct region_header header; + struct layout_region regions[]; +}; + +struct index_save_data { + u64 timestamp; + u64 nonce; + /* Currently always version 1 */ + u32 version; + u32 unused__; +}; + +struct index_state_version { + s32 signature; + s32 version_id; +}; + +static const struct index_state_version INDEX_STATE_VERSION_301 = { + .signature = -1, + .version_id = 301, +}; + +struct index_state_data301 { + struct index_state_version version; + u64 newest_chapter; + u64 oldest_chapter; + u64 last_save; + u32 unused; + u32 padding; +}; + +struct index_save_layout { + unsigned int zone_count; + struct layout_region index_save; + struct layout_region header; + struct layout_region index_page_map; + struct layout_region free_space; + struct layout_region volume_index_zones[MAX_ZONES]; + struct layout_region open_chapter; + struct index_save_data save_data; + struct index_state_data301 state_data; +}; + +struct sub_index_layout { + u64 nonce; + struct layout_region sub_index; + struct layout_region volume; + struct index_save_layout *saves; +}; + +struct super_block_data { + u8 magic_label[MAGIC_SIZE]; + u8 nonce_info[NONCE_INFO_SIZE]; + u64 nonce; + u32 version; + u32 block_size; + u16 index_count; + u16 max_saves; + /* Padding reflects a blank field on permanent storage */ + u8 padding[4]; + u64 open_chapter_blocks; + u64 page_map_blocks; + u64 volume_offset; + u64 start_offset; +}; + +struct index_layout { + struct io_factory *factory; + size_t factory_size; + off_t offset; + struct super_block_data super; + struct layout_region header; + struct layout_region config; + struct sub_index_layout index; + struct layout_region seal; + u64 total_blocks; +}; + +struct save_layout_sizes { + unsigned int save_count; + size_t block_size; + u64 volume_blocks; + u64 volume_index_blocks; + u64 page_map_blocks; + u64 open_chapter_blocks; + u64 save_blocks; + u64 sub_index_blocks; + u64 total_blocks; + size_t total_size; +}; + +static inline bool is_converted_super_block(struct super_block_data *super) +{ + return super->version == 7; +} + +static int __must_check compute_sizes(const struct uds_configuration *config, + struct save_layout_sizes *sls) +{ + int result; + struct index_geometry *geometry = config->geometry; + + memset(sls, 0, sizeof(*sls)); + sls->save_count = MAX_SAVES; + sls->block_size = UDS_BLOCK_SIZE; + sls->volume_blocks = geometry->bytes_per_volume / sls->block_size; + + result = uds_compute_volume_index_save_blocks(config, sls->block_size, + &sls->volume_index_blocks); + if (result != UDS_SUCCESS) + return vdo_log_error_strerror(result, "cannot compute index save size"); + + sls->page_map_blocks = + DIV_ROUND_UP(uds_compute_index_page_map_save_size(geometry), + sls->block_size); + sls->open_chapter_blocks = + DIV_ROUND_UP(uds_compute_saved_open_chapter_size(geometry), + sls->block_size); + sls->save_blocks = + 1 + (sls->volume_index_blocks + sls->page_map_blocks + sls->open_chapter_blocks); + sls->sub_index_blocks = sls->volume_blocks + (sls->save_count * sls->save_blocks); + sls->total_blocks = 3 + sls->sub_index_blocks; + sls->total_size = sls->total_blocks * sls->block_size; + + return UDS_SUCCESS; +} + +int uds_compute_index_size(const struct uds_parameters *parameters, u64 *index_size) +{ + int result; + struct uds_configuration *index_config; + struct save_layout_sizes sizes; + + if (index_size == NULL) { + vdo_log_error("Missing output size pointer"); + return -EINVAL; + } + + result = uds_make_configuration(parameters, &index_config); + if (result != UDS_SUCCESS) { + vdo_log_error_strerror(result, "cannot compute index size"); + return uds_status_to_errno(result); + } + + result = compute_sizes(index_config, &sizes); + uds_free_configuration(index_config); + if (result != UDS_SUCCESS) + return uds_status_to_errno(result); + + *index_size = sizes.total_size; + return UDS_SUCCESS; +} + +/* Create unique data using the current time and a pseudorandom number. */ +static void create_unique_nonce_data(u8 *buffer) +{ + ktime_t now = current_time_ns(CLOCK_REALTIME); + u32 rand; + size_t offset = 0; + + get_random_bytes(&rand, sizeof(u32)); + memcpy(buffer + offset, &now, sizeof(now)); + offset += sizeof(now); + memcpy(buffer + offset, &rand, sizeof(rand)); + offset += sizeof(rand); + while (offset < NONCE_INFO_SIZE) { + size_t len = min(NONCE_INFO_SIZE - offset, offset); + + memcpy(buffer + offset, buffer, len); + offset += len; + } +} + +static u64 hash_stuff(u64 start, const void *data, size_t len) +{ + u32 seed = start ^ (start >> 27); + u8 hash_buffer[16]; + + murmurhash3_128(data, len, seed, hash_buffer); + return get_unaligned_le64(hash_buffer + 4); +} + +/* Generate a primary nonce from the provided data. */ +static u64 generate_primary_nonce(const void *data, size_t len) +{ + return hash_stuff(0xa1b1e0fc, data, len); +} + +/* + * Deterministically generate a secondary nonce from an existing nonce and some arbitrary data by + * hashing the original nonce and the data to produce a new nonce. + */ +static u64 generate_secondary_nonce(u64 nonce, const void *data, size_t len) +{ + return hash_stuff(nonce + 1, data, len); +} + +static int __must_check open_layout_reader(struct index_layout *layout, + struct layout_region *lr, off_t offset, + struct buffered_reader **reader_ptr) +{ + return uds_make_buffered_reader(layout->factory, lr->start_block + offset, + lr->block_count, reader_ptr); +} + +static int open_region_reader(struct index_layout *layout, struct layout_region *region, + struct buffered_reader **reader_ptr) +{ + return open_layout_reader(layout, region, -layout->super.start_offset, + reader_ptr); +} + +static int __must_check open_layout_writer(struct index_layout *layout, + struct layout_region *lr, off_t offset, + struct buffered_writer **writer_ptr) +{ + return uds_make_buffered_writer(layout->factory, lr->start_block + offset, + lr->block_count, writer_ptr); +} + +static int open_region_writer(struct index_layout *layout, struct layout_region *region, + struct buffered_writer **writer_ptr) +{ + return open_layout_writer(layout, region, -layout->super.start_offset, + writer_ptr); +} + +static void generate_super_block_data(struct save_layout_sizes *sls, + struct super_block_data *super) +{ + memset(super, 0, sizeof(*super)); + memcpy(super->magic_label, LAYOUT_MAGIC, MAGIC_SIZE); + create_unique_nonce_data(super->nonce_info); + + super->nonce = generate_primary_nonce(super->nonce_info, + sizeof(super->nonce_info)); + super->version = SUPER_VERSION_CURRENT; + super->block_size = sls->block_size; + super->index_count = 1; + super->max_saves = sls->save_count; + super->open_chapter_blocks = sls->open_chapter_blocks; + super->page_map_blocks = sls->page_map_blocks; + super->volume_offset = 0; + super->start_offset = 0; +} + +static void define_sub_index_nonce(struct index_layout *layout) +{ + struct sub_index_nonce_data { + u64 offset; + u16 index_id; + }; + struct sub_index_layout *sil = &layout->index; + u64 primary_nonce = layout->super.nonce; + u8 buffer[sizeof(struct sub_index_nonce_data)] = { 0 }; + size_t offset = 0; + + encode_u64_le(buffer, &offset, sil->sub_index.start_block); + encode_u16_le(buffer, &offset, 0); + sil->nonce = generate_secondary_nonce(primary_nonce, buffer, sizeof(buffer)); + if (sil->nonce == 0) { + sil->nonce = generate_secondary_nonce(~primary_nonce + 1, buffer, + sizeof(buffer)); + } +} + +static void setup_sub_index(struct index_layout *layout, u64 start_block, + struct save_layout_sizes *sls) +{ + struct sub_index_layout *sil = &layout->index; + u64 next_block = start_block; + unsigned int i; + + sil->sub_index = (struct layout_region) { + .start_block = start_block, + .block_count = sls->sub_index_blocks, + .kind = RL_KIND_INDEX, + .instance = 0, + }; + + sil->volume = (struct layout_region) { + .start_block = next_block, + .block_count = sls->volume_blocks, + .kind = RL_KIND_VOLUME, + .instance = RL_SOLE_INSTANCE, + }; + + next_block += sls->volume_blocks; + + for (i = 0; i < sls->save_count; i++) { + sil->saves[i].index_save = (struct layout_region) { + .start_block = next_block, + .block_count = sls->save_blocks, + .kind = RL_KIND_SAVE, + .instance = i, + }; + + next_block += sls->save_blocks; + } + + define_sub_index_nonce(layout); +} + +static void initialize_layout(struct index_layout *layout, struct save_layout_sizes *sls) +{ + u64 next_block = layout->offset / sls->block_size; + + layout->total_blocks = sls->total_blocks; + generate_super_block_data(sls, &layout->super); + layout->header = (struct layout_region) { + .start_block = next_block++, + .block_count = 1, + .kind = RL_KIND_HEADER, + .instance = RL_SOLE_INSTANCE, + }; + + layout->config = (struct layout_region) { + .start_block = next_block++, + .block_count = 1, + .kind = RL_KIND_CONFIG, + .instance = RL_SOLE_INSTANCE, + }; + + setup_sub_index(layout, next_block, sls); + next_block += sls->sub_index_blocks; + + layout->seal = (struct layout_region) { + .start_block = next_block, + .block_count = 1, + .kind = RL_KIND_SEAL, + .instance = RL_SOLE_INSTANCE, + }; +} + +static int __must_check make_index_save_region_table(struct index_save_layout *isl, + struct region_table **table_ptr) +{ + int result; + unsigned int z; + struct region_table *table; + struct layout_region *lr; + u16 region_count; + size_t payload; + size_t type; + + if (isl->zone_count > 0) { + /* + * Normal save regions: header, page map, volume index zones, + * open chapter, and possibly free space. + */ + region_count = 3 + isl->zone_count; + if (isl->free_space.block_count > 0) + region_count++; + + payload = sizeof(isl->save_data) + sizeof(isl->state_data); + type = RH_TYPE_SAVE; + } else { + /* Empty save regions: header, page map, free space. */ + region_count = 3; + payload = sizeof(isl->save_data); + type = RH_TYPE_UNSAVED; + } + + result = vdo_allocate_extended(struct region_table, region_count, + struct layout_region, + "layout region table for ISL", &table); + if (result != VDO_SUCCESS) + return result; + + lr = &table->regions[0]; + *lr++ = isl->header; + *lr++ = isl->index_page_map; + for (z = 0; z < isl->zone_count; z++) + *lr++ = isl->volume_index_zones[z]; + + if (isl->zone_count > 0) + *lr++ = isl->open_chapter; + + if (isl->free_space.block_count > 0) + *lr++ = isl->free_space; + + table->header = (struct region_header) { + .magic = REGION_MAGIC, + .region_blocks = isl->index_save.block_count, + .type = type, + .version = 1, + .region_count = region_count, + .payload = payload, + }; + + table->encoded_size = (sizeof(struct region_header) + payload + + region_count * sizeof(struct layout_region)); + *table_ptr = table; + return UDS_SUCCESS; +} + +static void encode_region_table(u8 *buffer, size_t *offset, struct region_table *table) +{ + unsigned int i; + + encode_u64_le(buffer, offset, REGION_MAGIC); + encode_u64_le(buffer, offset, table->header.region_blocks); + encode_u16_le(buffer, offset, table->header.type); + encode_u16_le(buffer, offset, table->header.version); + encode_u16_le(buffer, offset, table->header.region_count); + encode_u16_le(buffer, offset, table->header.payload); + + for (i = 0; i < table->header.region_count; i++) { + encode_u64_le(buffer, offset, table->regions[i].start_block); + encode_u64_le(buffer, offset, table->regions[i].block_count); + encode_u32_le(buffer, offset, 0); + encode_u16_le(buffer, offset, table->regions[i].kind); + encode_u16_le(buffer, offset, table->regions[i].instance); + } +} + +static int __must_check write_index_save_header(struct index_save_layout *isl, + struct region_table *table, + struct buffered_writer *writer) +{ + int result; + u8 *buffer; + size_t offset = 0; + + result = vdo_allocate(table->encoded_size, u8, "index save data", &buffer); + if (result != VDO_SUCCESS) + return result; + + encode_region_table(buffer, &offset, table); + encode_u64_le(buffer, &offset, isl->save_data.timestamp); + encode_u64_le(buffer, &offset, isl->save_data.nonce); + encode_u32_le(buffer, &offset, isl->save_data.version); + encode_u32_le(buffer, &offset, 0); + if (isl->zone_count > 0) { + encode_u32_le(buffer, &offset, INDEX_STATE_VERSION_301.signature); + encode_u32_le(buffer, &offset, INDEX_STATE_VERSION_301.version_id); + encode_u64_le(buffer, &offset, isl->state_data.newest_chapter); + encode_u64_le(buffer, &offset, isl->state_data.oldest_chapter); + encode_u64_le(buffer, &offset, isl->state_data.last_save); + encode_u64_le(buffer, &offset, 0); + } + + result = uds_write_to_buffered_writer(writer, buffer, offset); + vdo_free(buffer); + if (result != UDS_SUCCESS) + return result; + + return uds_flush_buffered_writer(writer); +} + +static int write_index_save_layout(struct index_layout *layout, + struct index_save_layout *isl) +{ + int result; + struct region_table *table; + struct buffered_writer *writer; + + result = make_index_save_region_table(isl, &table); + if (result != UDS_SUCCESS) + return result; + + result = open_region_writer(layout, &isl->header, &writer); + if (result != UDS_SUCCESS) { + vdo_free(table); + return result; + } + + result = write_index_save_header(isl, table, writer); + vdo_free(table); + uds_free_buffered_writer(writer); + + return result; +} + +static void reset_index_save_layout(struct index_save_layout *isl, u64 page_map_blocks) +{ + u64 free_blocks; + u64 next_block = isl->index_save.start_block; + + isl->zone_count = 0; + memset(&isl->save_data, 0, sizeof(isl->save_data)); + + isl->header = (struct layout_region) { + .start_block = next_block++, + .block_count = 1, + .kind = RL_KIND_HEADER, + .instance = RL_SOLE_INSTANCE, + }; + + isl->index_page_map = (struct layout_region) { + .start_block = next_block, + .block_count = page_map_blocks, + .kind = RL_KIND_INDEX_PAGE_MAP, + .instance = RL_SOLE_INSTANCE, + }; + + next_block += page_map_blocks; + + free_blocks = isl->index_save.block_count - page_map_blocks - 1; + isl->free_space = (struct layout_region) { + .start_block = next_block, + .block_count = free_blocks, + .kind = RL_KIND_EMPTY, + .instance = RL_SOLE_INSTANCE, + }; +} + +static int __must_check invalidate_old_save(struct index_layout *layout, + struct index_save_layout *isl) +{ + reset_index_save_layout(isl, layout->super.page_map_blocks); + return write_index_save_layout(layout, isl); +} + +static int discard_index_state_data(struct index_layout *layout) +{ + int result; + int saved_result = UDS_SUCCESS; + unsigned int i; + + for (i = 0; i < layout->super.max_saves; i++) { + result = invalidate_old_save(layout, &layout->index.saves[i]); + if (result != UDS_SUCCESS) + saved_result = result; + } + + if (saved_result != UDS_SUCCESS) { + return vdo_log_error_strerror(result, + "%s: cannot destroy all index saves", + __func__); + } + + return UDS_SUCCESS; +} + +static int __must_check make_layout_region_table(struct index_layout *layout, + struct region_table **table_ptr) +{ + int result; + unsigned int i; + /* Regions: header, config, index, volume, saves, seal */ + u16 region_count = 5 + layout->super.max_saves; + u16 payload; + struct region_table *table; + struct layout_region *lr; + + result = vdo_allocate_extended(struct region_table, region_count, + struct layout_region, "layout region table", + &table); + if (result != VDO_SUCCESS) + return result; + + lr = &table->regions[0]; + *lr++ = layout->header; + *lr++ = layout->config; + *lr++ = layout->index.sub_index; + *lr++ = layout->index.volume; + + for (i = 0; i < layout->super.max_saves; i++) + *lr++ = layout->index.saves[i].index_save; + + *lr++ = layout->seal; + + if (is_converted_super_block(&layout->super)) { + payload = sizeof(struct super_block_data); + } else { + payload = (sizeof(struct super_block_data) - + sizeof(layout->super.volume_offset) - + sizeof(layout->super.start_offset)); + } + + table->header = (struct region_header) { + .magic = REGION_MAGIC, + .region_blocks = layout->total_blocks, + .type = RH_TYPE_SUPER, + .version = 1, + .region_count = region_count, + .payload = payload, + }; + + table->encoded_size = (sizeof(struct region_header) + payload + + region_count * sizeof(struct layout_region)); + *table_ptr = table; + return UDS_SUCCESS; +} + +static int __must_check write_layout_header(struct index_layout *layout, + struct region_table *table, + struct buffered_writer *writer) +{ + int result; + u8 *buffer; + size_t offset = 0; + + result = vdo_allocate(table->encoded_size, u8, "layout data", &buffer); + if (result != VDO_SUCCESS) + return result; + + encode_region_table(buffer, &offset, table); + memcpy(buffer + offset, &layout->super.magic_label, MAGIC_SIZE); + offset += MAGIC_SIZE; + memcpy(buffer + offset, &layout->super.nonce_info, NONCE_INFO_SIZE); + offset += NONCE_INFO_SIZE; + encode_u64_le(buffer, &offset, layout->super.nonce); + encode_u32_le(buffer, &offset, layout->super.version); + encode_u32_le(buffer, &offset, layout->super.block_size); + encode_u16_le(buffer, &offset, layout->super.index_count); + encode_u16_le(buffer, &offset, layout->super.max_saves); + encode_u32_le(buffer, &offset, 0); + encode_u64_le(buffer, &offset, layout->super.open_chapter_blocks); + encode_u64_le(buffer, &offset, layout->super.page_map_blocks); + + if (is_converted_super_block(&layout->super)) { + encode_u64_le(buffer, &offset, layout->super.volume_offset); + encode_u64_le(buffer, &offset, layout->super.start_offset); + } + + result = uds_write_to_buffered_writer(writer, buffer, offset); + vdo_free(buffer); + if (result != UDS_SUCCESS) + return result; + + return uds_flush_buffered_writer(writer); +} + +static int __must_check write_uds_index_config(struct index_layout *layout, + struct uds_configuration *config, + off_t offset) +{ + int result; + struct buffered_writer *writer = NULL; + + result = open_layout_writer(layout, &layout->config, offset, &writer); + if (result != UDS_SUCCESS) + return vdo_log_error_strerror(result, "failed to open config region"); + + result = uds_write_config_contents(writer, config, layout->super.version); + if (result != UDS_SUCCESS) { + uds_free_buffered_writer(writer); + return vdo_log_error_strerror(result, "failed to write config region"); + } + + result = uds_flush_buffered_writer(writer); + if (result != UDS_SUCCESS) { + uds_free_buffered_writer(writer); + return vdo_log_error_strerror(result, "cannot flush config writer"); + } + + uds_free_buffered_writer(writer); + return UDS_SUCCESS; +} + +static int __must_check save_layout(struct index_layout *layout, off_t offset) +{ + int result; + struct buffered_writer *writer = NULL; + struct region_table *table; + + result = make_layout_region_table(layout, &table); + if (result != UDS_SUCCESS) + return result; + + result = open_layout_writer(layout, &layout->header, offset, &writer); + if (result != UDS_SUCCESS) { + vdo_free(table); + return result; + } + + result = write_layout_header(layout, table, writer); + vdo_free(table); + uds_free_buffered_writer(writer); + + return result; +} + +static int create_index_layout(struct index_layout *layout, struct uds_configuration *config) +{ + int result; + struct save_layout_sizes sizes; + + result = compute_sizes(config, &sizes); + if (result != UDS_SUCCESS) + return result; + + result = vdo_allocate(sizes.save_count, struct index_save_layout, __func__, + &layout->index.saves); + if (result != VDO_SUCCESS) + return result; + + initialize_layout(layout, &sizes); + + result = discard_index_state_data(layout); + if (result != UDS_SUCCESS) + return result; + + result = write_uds_index_config(layout, config, 0); + if (result != UDS_SUCCESS) + return result; + + return save_layout(layout, 0); +} + +static u64 generate_index_save_nonce(u64 volume_nonce, struct index_save_layout *isl) +{ + struct save_nonce_data { + struct index_save_data data; + u64 offset; + } nonce_data; + u8 buffer[sizeof(nonce_data)]; + size_t offset = 0; + + encode_u64_le(buffer, &offset, isl->save_data.timestamp); + encode_u64_le(buffer, &offset, 0); + encode_u32_le(buffer, &offset, isl->save_data.version); + encode_u32_le(buffer, &offset, 0U); + encode_u64_le(buffer, &offset, isl->index_save.start_block); + VDO_ASSERT_LOG_ONLY(offset == sizeof(nonce_data), + "%zu bytes encoded of %zu expected", + offset, sizeof(nonce_data)); + return generate_secondary_nonce(volume_nonce, buffer, sizeof(buffer)); +} + +static u64 validate_index_save_layout(struct index_save_layout *isl, u64 volume_nonce) +{ + if ((isl->zone_count == 0) || (isl->save_data.timestamp == 0)) + return 0; + + if (isl->save_data.nonce != generate_index_save_nonce(volume_nonce, isl)) + return 0; + + return isl->save_data.timestamp; +} + +static int find_latest_uds_index_save_slot(struct index_layout *layout, + struct index_save_layout **isl_ptr) +{ + struct index_save_layout *latest = NULL; + struct index_save_layout *isl; + unsigned int i; + u64 save_time = 0; + u64 latest_time = 0; + + for (i = 0; i < layout->super.max_saves; i++) { + isl = &layout->index.saves[i]; + save_time = validate_index_save_layout(isl, layout->index.nonce); + if (save_time > latest_time) { + latest = isl; + latest_time = save_time; + } + } + + if (latest == NULL) { + vdo_log_error("No valid index save found"); + return UDS_INDEX_NOT_SAVED_CLEANLY; + } + + *isl_ptr = latest; + return UDS_SUCCESS; +} + +int uds_discard_open_chapter(struct index_layout *layout) +{ + int result; + struct index_save_layout *isl; + struct buffered_writer *writer; + + result = find_latest_uds_index_save_slot(layout, &isl); + if (result != UDS_SUCCESS) + return result; + + result = open_region_writer(layout, &isl->open_chapter, &writer); + if (result != UDS_SUCCESS) + return result; + + result = uds_write_to_buffered_writer(writer, NULL, UDS_BLOCK_SIZE); + if (result != UDS_SUCCESS) { + uds_free_buffered_writer(writer); + return result; + } + + result = uds_flush_buffered_writer(writer); + uds_free_buffered_writer(writer); + return result; +} + +int uds_load_index_state(struct index_layout *layout, struct uds_index *index) +{ + int result; + unsigned int zone; + struct index_save_layout *isl; + struct buffered_reader *readers[MAX_ZONES]; + + result = find_latest_uds_index_save_slot(layout, &isl); + if (result != UDS_SUCCESS) + return result; + + index->newest_virtual_chapter = isl->state_data.newest_chapter; + index->oldest_virtual_chapter = isl->state_data.oldest_chapter; + index->last_save = isl->state_data.last_save; + + result = open_region_reader(layout, &isl->open_chapter, &readers[0]); + if (result != UDS_SUCCESS) + return result; + + result = uds_load_open_chapter(index, readers[0]); + uds_free_buffered_reader(readers[0]); + if (result != UDS_SUCCESS) + return result; + + for (zone = 0; zone < isl->zone_count; zone++) { + result = open_region_reader(layout, &isl->volume_index_zones[zone], + &readers[zone]); + if (result != UDS_SUCCESS) { + for (; zone > 0; zone--) + uds_free_buffered_reader(readers[zone - 1]); + + return result; + } + } + + result = uds_load_volume_index(index->volume_index, readers, isl->zone_count); + for (zone = 0; zone < isl->zone_count; zone++) + uds_free_buffered_reader(readers[zone]); + if (result != UDS_SUCCESS) + return result; + + result = open_region_reader(layout, &isl->index_page_map, &readers[0]); + if (result != UDS_SUCCESS) + return result; + + result = uds_read_index_page_map(index->volume->index_page_map, readers[0]); + uds_free_buffered_reader(readers[0]); + + return result; +} + +static struct index_save_layout *select_oldest_index_save_layout(struct index_layout *layout) +{ + struct index_save_layout *oldest = NULL; + struct index_save_layout *isl; + unsigned int i; + u64 save_time = 0; + u64 oldest_time = 0; + + for (i = 0; i < layout->super.max_saves; i++) { + isl = &layout->index.saves[i]; + save_time = validate_index_save_layout(isl, layout->index.nonce); + if (oldest == NULL || save_time < oldest_time) { + oldest = isl; + oldest_time = save_time; + } + } + + return oldest; +} + +static void instantiate_index_save_layout(struct index_save_layout *isl, + struct super_block_data *super, + u64 volume_nonce, unsigned int zone_count) +{ + unsigned int z; + u64 next_block; + u64 free_blocks; + u64 volume_index_blocks; + + isl->zone_count = zone_count; + memset(&isl->save_data, 0, sizeof(isl->save_data)); + isl->save_data.timestamp = ktime_to_ms(current_time_ns(CLOCK_REALTIME)); + isl->save_data.version = 1; + isl->save_data.nonce = generate_index_save_nonce(volume_nonce, isl); + + next_block = isl->index_save.start_block; + isl->header = (struct layout_region) { + .start_block = next_block++, + .block_count = 1, + .kind = RL_KIND_HEADER, + .instance = RL_SOLE_INSTANCE, + }; + + isl->index_page_map = (struct layout_region) { + .start_block = next_block, + .block_count = super->page_map_blocks, + .kind = RL_KIND_INDEX_PAGE_MAP, + .instance = RL_SOLE_INSTANCE, + }; + next_block += super->page_map_blocks; + + free_blocks = (isl->index_save.block_count - 1 - + super->page_map_blocks - + super->open_chapter_blocks); + volume_index_blocks = free_blocks / isl->zone_count; + for (z = 0; z < isl->zone_count; z++) { + isl->volume_index_zones[z] = (struct layout_region) { + .start_block = next_block, + .block_count = volume_index_blocks, + .kind = RL_KIND_VOLUME_INDEX, + .instance = z, + }; + + next_block += volume_index_blocks; + free_blocks -= volume_index_blocks; + } + + isl->open_chapter = (struct layout_region) { + .start_block = next_block, + .block_count = super->open_chapter_blocks, + .kind = RL_KIND_OPEN_CHAPTER, + .instance = RL_SOLE_INSTANCE, + }; + + next_block += super->open_chapter_blocks; + + isl->free_space = (struct layout_region) { + .start_block = next_block, + .block_count = free_blocks, + .kind = RL_KIND_EMPTY, + .instance = RL_SOLE_INSTANCE, + }; +} + +static int setup_uds_index_save_slot(struct index_layout *layout, + unsigned int zone_count, + struct index_save_layout **isl_ptr) +{ + int result; + struct index_save_layout *isl; + + isl = select_oldest_index_save_layout(layout); + result = invalidate_old_save(layout, isl); + if (result != UDS_SUCCESS) + return result; + + instantiate_index_save_layout(isl, &layout->super, layout->index.nonce, + zone_count); + + *isl_ptr = isl; + return UDS_SUCCESS; +} + +static void cancel_uds_index_save(struct index_save_layout *isl) +{ + memset(&isl->save_data, 0, sizeof(isl->save_data)); + memset(&isl->state_data, 0, sizeof(isl->state_data)); + isl->zone_count = 0; +} + +int uds_save_index_state(struct index_layout *layout, struct uds_index *index) +{ + int result; + unsigned int zone; + struct index_save_layout *isl; + struct buffered_writer *writers[MAX_ZONES]; + + result = setup_uds_index_save_slot(layout, index->zone_count, &isl); + if (result != UDS_SUCCESS) + return result; + + isl->state_data = (struct index_state_data301) { + .newest_chapter = index->newest_virtual_chapter, + .oldest_chapter = index->oldest_virtual_chapter, + .last_save = index->last_save, + }; + + result = open_region_writer(layout, &isl->open_chapter, &writers[0]); + if (result != UDS_SUCCESS) { + cancel_uds_index_save(isl); + return result; + } + + result = uds_save_open_chapter(index, writers[0]); + uds_free_buffered_writer(writers[0]); + if (result != UDS_SUCCESS) { + cancel_uds_index_save(isl); + return result; + } + + for (zone = 0; zone < index->zone_count; zone++) { + result = open_region_writer(layout, &isl->volume_index_zones[zone], + &writers[zone]); + if (result != UDS_SUCCESS) { + for (; zone > 0; zone--) + uds_free_buffered_writer(writers[zone - 1]); + + cancel_uds_index_save(isl); + return result; + } + } + + result = uds_save_volume_index(index->volume_index, writers, index->zone_count); + for (zone = 0; zone < index->zone_count; zone++) + uds_free_buffered_writer(writers[zone]); + if (result != UDS_SUCCESS) { + cancel_uds_index_save(isl); + return result; + } + + result = open_region_writer(layout, &isl->index_page_map, &writers[0]); + if (result != UDS_SUCCESS) { + cancel_uds_index_save(isl); + return result; + } + + result = uds_write_index_page_map(index->volume->index_page_map, writers[0]); + uds_free_buffered_writer(writers[0]); + if (result != UDS_SUCCESS) { + cancel_uds_index_save(isl); + return result; + } + + return write_index_save_layout(layout, isl); +} + +static int __must_check load_region_table(struct buffered_reader *reader, + struct region_table **table_ptr) +{ + int result; + unsigned int i; + struct region_header header; + struct region_table *table; + u8 buffer[sizeof(struct region_header)]; + size_t offset = 0; + + result = uds_read_from_buffered_reader(reader, buffer, sizeof(buffer)); + if (result != UDS_SUCCESS) + return vdo_log_error_strerror(result, "cannot read region table header"); + + decode_u64_le(buffer, &offset, &header.magic); + decode_u64_le(buffer, &offset, &header.region_blocks); + decode_u16_le(buffer, &offset, &header.type); + decode_u16_le(buffer, &offset, &header.version); + decode_u16_le(buffer, &offset, &header.region_count); + decode_u16_le(buffer, &offset, &header.payload); + + if (header.magic != REGION_MAGIC) + return UDS_NO_INDEX; + + if (header.version != 1) { + return vdo_log_error_strerror(UDS_UNSUPPORTED_VERSION, + "unknown region table version %hu", + header.version); + } + + result = vdo_allocate_extended(struct region_table, header.region_count, + struct layout_region, + "single file layout region table", &table); + if (result != VDO_SUCCESS) + return result; + + table->header = header; + for (i = 0; i < header.region_count; i++) { + u8 region_buffer[sizeof(struct layout_region)]; + + offset = 0; + result = uds_read_from_buffered_reader(reader, region_buffer, + sizeof(region_buffer)); + if (result != UDS_SUCCESS) { + vdo_free(table); + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "cannot read region table layouts"); + } + + decode_u64_le(region_buffer, &offset, &table->regions[i].start_block); + decode_u64_le(region_buffer, &offset, &table->regions[i].block_count); + offset += sizeof(u32); + decode_u16_le(region_buffer, &offset, &table->regions[i].kind); + decode_u16_le(region_buffer, &offset, &table->regions[i].instance); + } + + *table_ptr = table; + return UDS_SUCCESS; +} + +static int __must_check read_super_block_data(struct buffered_reader *reader, + struct index_layout *layout, + size_t saved_size) +{ + int result; + struct super_block_data *super = &layout->super; + u8 *buffer; + size_t offset = 0; + + result = vdo_allocate(saved_size, u8, "super block data", &buffer); + if (result != VDO_SUCCESS) + return result; + + result = uds_read_from_buffered_reader(reader, buffer, saved_size); + if (result != UDS_SUCCESS) { + vdo_free(buffer); + return vdo_log_error_strerror(result, "cannot read region table header"); + } + + memcpy(&super->magic_label, buffer, MAGIC_SIZE); + offset += MAGIC_SIZE; + memcpy(&super->nonce_info, buffer + offset, NONCE_INFO_SIZE); + offset += NONCE_INFO_SIZE; + decode_u64_le(buffer, &offset, &super->nonce); + decode_u32_le(buffer, &offset, &super->version); + decode_u32_le(buffer, &offset, &super->block_size); + decode_u16_le(buffer, &offset, &super->index_count); + decode_u16_le(buffer, &offset, &super->max_saves); + offset += sizeof(u32); + decode_u64_le(buffer, &offset, &super->open_chapter_blocks); + decode_u64_le(buffer, &offset, &super->page_map_blocks); + + if (is_converted_super_block(super)) { + decode_u64_le(buffer, &offset, &super->volume_offset); + decode_u64_le(buffer, &offset, &super->start_offset); + } else { + super->volume_offset = 0; + super->start_offset = 0; + } + + vdo_free(buffer); + + if (memcmp(super->magic_label, LAYOUT_MAGIC, MAGIC_SIZE) != 0) + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "unknown superblock magic label"); + + if ((super->version < SUPER_VERSION_MINIMUM) || + (super->version == 4) || (super->version == 5) || (super->version == 6) || + (super->version > SUPER_VERSION_MAXIMUM)) { + return vdo_log_error_strerror(UDS_UNSUPPORTED_VERSION, + "unknown superblock version number %u", + super->version); + } + + if (super->volume_offset < super->start_offset) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "inconsistent offsets (start %llu, volume %llu)", + (unsigned long long) super->start_offset, + (unsigned long long) super->volume_offset); + } + + /* Sub-indexes are no longer used but the layout retains this field. */ + if (super->index_count != 1) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "invalid subindex count %u", + super->index_count); + } + + if (generate_primary_nonce(super->nonce_info, sizeof(super->nonce_info)) != super->nonce) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "inconsistent superblock nonce"); + } + + return UDS_SUCCESS; +} + +static int __must_check verify_region(struct layout_region *lr, u64 start_block, + enum region_kind kind, unsigned int instance) +{ + if (lr->start_block != start_block) + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "incorrect layout region offset"); + + if (lr->kind != kind) + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "incorrect layout region kind"); + + if (lr->instance != instance) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "incorrect layout region instance"); + } + + return UDS_SUCCESS; +} + +static int __must_check verify_sub_index(struct index_layout *layout, u64 start_block, + struct region_table *table) +{ + int result; + unsigned int i; + struct sub_index_layout *sil = &layout->index; + u64 next_block = start_block; + + sil->sub_index = table->regions[2]; + result = verify_region(&sil->sub_index, next_block, RL_KIND_INDEX, 0); + if (result != UDS_SUCCESS) + return result; + + define_sub_index_nonce(layout); + + sil->volume = table->regions[3]; + result = verify_region(&sil->volume, next_block, RL_KIND_VOLUME, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + next_block += sil->volume.block_count + layout->super.volume_offset; + + for (i = 0; i < layout->super.max_saves; i++) { + sil->saves[i].index_save = table->regions[i + 4]; + result = verify_region(&sil->saves[i].index_save, next_block, + RL_KIND_SAVE, i); + if (result != UDS_SUCCESS) + return result; + + next_block += sil->saves[i].index_save.block_count; + } + + next_block -= layout->super.volume_offset; + if (next_block != start_block + sil->sub_index.block_count) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "sub index region does not span all saves"); + } + + return UDS_SUCCESS; +} + +static int __must_check reconstitute_layout(struct index_layout *layout, + struct region_table *table, u64 first_block) +{ + int result; + u64 next_block = first_block; + + result = vdo_allocate(layout->super.max_saves, struct index_save_layout, + __func__, &layout->index.saves); + if (result != VDO_SUCCESS) + return result; + + layout->total_blocks = table->header.region_blocks; + + layout->header = table->regions[0]; + result = verify_region(&layout->header, next_block++, RL_KIND_HEADER, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + layout->config = table->regions[1]; + result = verify_region(&layout->config, next_block++, RL_KIND_CONFIG, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + result = verify_sub_index(layout, next_block, table); + if (result != UDS_SUCCESS) + return result; + + next_block += layout->index.sub_index.block_count; + + layout->seal = table->regions[table->header.region_count - 1]; + result = verify_region(&layout->seal, next_block + layout->super.volume_offset, + RL_KIND_SEAL, RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + if (++next_block != (first_block + layout->total_blocks)) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "layout table does not span total blocks"); + } + + return UDS_SUCCESS; +} + +static int __must_check load_super_block(struct index_layout *layout, size_t block_size, + u64 first_block, struct buffered_reader *reader) +{ + int result; + struct region_table *table = NULL; + struct super_block_data *super = &layout->super; + + result = load_region_table(reader, &table); + if (result != UDS_SUCCESS) + return result; + + if (table->header.type != RH_TYPE_SUPER) { + vdo_free(table); + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "not a superblock region table"); + } + + result = read_super_block_data(reader, layout, table->header.payload); + if (result != UDS_SUCCESS) { + vdo_free(table); + return vdo_log_error_strerror(result, "unknown superblock format"); + } + + if (super->block_size != block_size) { + vdo_free(table); + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "superblock saved block_size %u differs from supplied block_size %zu", + super->block_size, block_size); + } + + first_block -= (super->volume_offset - super->start_offset); + result = reconstitute_layout(layout, table, first_block); + vdo_free(table); + return result; +} + +static int __must_check read_index_save_data(struct buffered_reader *reader, + struct index_save_layout *isl, + size_t saved_size) +{ + int result; + struct index_state_version file_version; + u8 buffer[sizeof(struct index_save_data) + sizeof(struct index_state_data301)]; + size_t offset = 0; + + if (saved_size != sizeof(buffer)) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "unexpected index save data size %zu", + saved_size); + } + + result = uds_read_from_buffered_reader(reader, buffer, sizeof(buffer)); + if (result != UDS_SUCCESS) + return vdo_log_error_strerror(result, "cannot read index save data"); + + decode_u64_le(buffer, &offset, &isl->save_data.timestamp); + decode_u64_le(buffer, &offset, &isl->save_data.nonce); + decode_u32_le(buffer, &offset, &isl->save_data.version); + offset += sizeof(u32); + + if (isl->save_data.version > 1) { + return vdo_log_error_strerror(UDS_UNSUPPORTED_VERSION, + "unknown index save version number %u", + isl->save_data.version); + } + + decode_s32_le(buffer, &offset, &file_version.signature); + decode_s32_le(buffer, &offset, &file_version.version_id); + + if ((file_version.signature != INDEX_STATE_VERSION_301.signature) || + (file_version.version_id != INDEX_STATE_VERSION_301.version_id)) { + return vdo_log_error_strerror(UDS_UNSUPPORTED_VERSION, + "index state version %d,%d is unsupported", + file_version.signature, + file_version.version_id); + } + + decode_u64_le(buffer, &offset, &isl->state_data.newest_chapter); + decode_u64_le(buffer, &offset, &isl->state_data.oldest_chapter); + decode_u64_le(buffer, &offset, &isl->state_data.last_save); + /* Skip past some historical fields that are now unused */ + offset += sizeof(u32) + sizeof(u32); + return UDS_SUCCESS; +} + +static int __must_check reconstruct_index_save(struct index_save_layout *isl, + struct region_table *table) +{ + int result; + unsigned int z; + struct layout_region *last_region; + u64 next_block = isl->index_save.start_block; + u64 last_block = next_block + isl->index_save.block_count; + + isl->zone_count = table->header.region_count - 3; + + last_region = &table->regions[table->header.region_count - 1]; + if (last_region->kind == RL_KIND_EMPTY) { + isl->free_space = *last_region; + isl->zone_count--; + } else { + isl->free_space = (struct layout_region) { + .start_block = last_block, + .block_count = 0, + .kind = RL_KIND_EMPTY, + .instance = RL_SOLE_INSTANCE, + }; + } + + isl->header = table->regions[0]; + result = verify_region(&isl->header, next_block++, RL_KIND_HEADER, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + isl->index_page_map = table->regions[1]; + result = verify_region(&isl->index_page_map, next_block, RL_KIND_INDEX_PAGE_MAP, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + next_block += isl->index_page_map.block_count; + + for (z = 0; z < isl->zone_count; z++) { + isl->volume_index_zones[z] = table->regions[z + 2]; + result = verify_region(&isl->volume_index_zones[z], next_block, + RL_KIND_VOLUME_INDEX, z); + if (result != UDS_SUCCESS) + return result; + + next_block += isl->volume_index_zones[z].block_count; + } + + isl->open_chapter = table->regions[isl->zone_count + 2]; + result = verify_region(&isl->open_chapter, next_block, RL_KIND_OPEN_CHAPTER, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + next_block += isl->open_chapter.block_count; + + result = verify_region(&isl->free_space, next_block, RL_KIND_EMPTY, + RL_SOLE_INSTANCE); + if (result != UDS_SUCCESS) + return result; + + next_block += isl->free_space.block_count; + if (next_block != last_block) { + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "index save layout table incomplete"); + } + + return UDS_SUCCESS; +} + +static int __must_check load_index_save(struct index_save_layout *isl, + struct buffered_reader *reader, + unsigned int instance) +{ + int result; + struct region_table *table = NULL; + + result = load_region_table(reader, &table); + if (result != UDS_SUCCESS) { + return vdo_log_error_strerror(result, "cannot read index save %u header", + instance); + } + + if (table->header.region_blocks != isl->index_save.block_count) { + u64 region_blocks = table->header.region_blocks; + + vdo_free(table); + return vdo_log_error_strerror(UDS_CORRUPT_DATA, + "unexpected index save %u region block count %llu", + instance, + (unsigned long long) region_blocks); + } + + if (table->header.type == RH_TYPE_UNSAVED) { + vdo_free(table); + reset_index_save_layout(isl, 0); + return UDS_SUCCESS; + } + + + if (table->header.type != RH_TYPE_SAVE) { + vdo_log_error_strerror(UDS_CORRUPT_DATA, + "unexpected index save %u header type %u", + instance, table->header.type); + vdo_free(table); + return UDS_CORRUPT_DATA; + } + + result = read_index_save_data(reader, isl, table->header.payload); + if (result != UDS_SUCCESS) { + vdo_free(table); + return vdo_log_error_strerror(result, + "unknown index save %u data format", + instance); + } + + result = reconstruct_index_save(isl, table); + vdo_free(table); + if (result != UDS_SUCCESS) { + return vdo_log_error_strerror(result, "cannot reconstruct index save %u", + instance); + } + + return UDS_SUCCESS; +} + +static int __must_check load_sub_index_regions(struct index_layout *layout) +{ + int result; + unsigned int j; + struct index_save_layout *isl; + struct buffered_reader *reader; + + for (j = 0; j < layout->super.max_saves; j++) { + isl = &layout->index.saves[j]; + result = open_region_reader(layout, &isl->index_save, &reader); + + if (result != UDS_SUCCESS) { + vdo_log_error_strerror(result, + "cannot get reader for index 0 save %u", + j); + return result; + } + + result = load_index_save(isl, reader, j); + uds_free_buffered_reader(reader); + if (result != UDS_SUCCESS) { + /* Another save slot might be valid. */ + reset_index_save_layout(isl, 0); + continue; + } + } + + return UDS_SUCCESS; +} + +static int __must_check verify_uds_index_config(struct index_layout *layout, + struct uds_configuration *config) +{ + int result; + struct buffered_reader *reader = NULL; + u64 offset; + + offset = layout->super.volume_offset - layout->super.start_offset; + result = open_layout_reader(layout, &layout->config, offset, &reader); + if (result != UDS_SUCCESS) + return vdo_log_error_strerror(result, "failed to open config reader"); + + result = uds_validate_config_contents(reader, config); + if (result != UDS_SUCCESS) { + uds_free_buffered_reader(reader); + return vdo_log_error_strerror(result, "failed to read config region"); + } + + uds_free_buffered_reader(reader); + return UDS_SUCCESS; +} + +static int load_index_layout(struct index_layout *layout, struct uds_configuration *config) +{ + int result; + struct buffered_reader *reader; + + result = uds_make_buffered_reader(layout->factory, + layout->offset / UDS_BLOCK_SIZE, 1, &reader); + if (result != UDS_SUCCESS) + return vdo_log_error_strerror(result, "unable to read superblock"); + + result = load_super_block(layout, UDS_BLOCK_SIZE, + layout->offset / UDS_BLOCK_SIZE, reader); + uds_free_buffered_reader(reader); + if (result != UDS_SUCCESS) + return result; + + result = verify_uds_index_config(layout, config); + if (result != UDS_SUCCESS) + return result; + + return load_sub_index_regions(layout); +} + +static int create_layout_factory(struct index_layout *layout, + const struct uds_configuration *config) +{ + int result; + size_t writable_size; + struct io_factory *factory = NULL; + + result = uds_make_io_factory(config->bdev, &factory); + if (result != UDS_SUCCESS) + return result; + + writable_size = uds_get_writable_size(factory) & -UDS_BLOCK_SIZE; + if (writable_size < config->size + config->offset) { + uds_put_io_factory(factory); + vdo_log_error("index storage (%zu) is smaller than the requested size %zu", + writable_size, config->size + config->offset); + return -ENOSPC; + } + + layout->factory = factory; + layout->factory_size = (config->size > 0) ? config->size : writable_size; + layout->offset = config->offset; + return UDS_SUCCESS; +} + +int uds_make_index_layout(struct uds_configuration *config, bool new_layout, + struct index_layout **layout_ptr) +{ + int result; + struct index_layout *layout = NULL; + struct save_layout_sizes sizes; + + result = compute_sizes(config, &sizes); + if (result != UDS_SUCCESS) + return result; + + result = vdo_allocate(1, struct index_layout, __func__, &layout); + if (result != VDO_SUCCESS) + return result; + + result = create_layout_factory(layout, config); + if (result != UDS_SUCCESS) { + uds_free_index_layout(layout); + return result; + } + + if (layout->factory_size < sizes.total_size) { + vdo_log_error("index storage (%zu) is smaller than the required size %llu", + layout->factory_size, + (unsigned long long) sizes.total_size); + uds_free_index_layout(layout); + return -ENOSPC; + } + + if (new_layout) + result = create_index_layout(layout, config); + else + result = load_index_layout(layout, config); + if (result != UDS_SUCCESS) { + uds_free_index_layout(layout); + return result; + } + + *layout_ptr = layout; + return UDS_SUCCESS; +} + +void uds_free_index_layout(struct index_layout *layout) +{ + if (layout == NULL) + return; + + vdo_free(layout->index.saves); + if (layout->factory != NULL) + uds_put_io_factory(layout->factory); + + vdo_free(layout); +} + +int uds_replace_index_layout_storage(struct index_layout *layout, + struct block_device *bdev) +{ + return uds_replace_storage(layout->factory, bdev); +} + +/* Obtain a dm_bufio_client for the volume region. */ +int uds_open_volume_bufio(struct index_layout *layout, size_t block_size, + unsigned int reserved_buffers, + struct dm_bufio_client **client_ptr) +{ + off_t offset = (layout->index.volume.start_block + + layout->super.volume_offset - + layout->super.start_offset); + + return uds_make_bufio(layout->factory, offset, block_size, reserved_buffers, + client_ptr); +} + +u64 uds_get_volume_nonce(struct index_layout *layout) +{ + return layout->index.nonce; +} |