Add vdo_encode_volume_geometry() to write the geometry block into a buffer so that it can be written to disk. The corresponding decode path already exists.
Signed-off-by: Bruce Johnston <[email protected]> --- drivers/md/dm-vdo/encodings.c | 56 +++++++++++++++++++++++++++++++++++ drivers/md/dm-vdo/encodings.h | 2 ++ 2 files changed, 58 insertions(+) diff --git a/drivers/md/dm-vdo/encodings.c b/drivers/md/dm-vdo/encodings.c index 3ceba010f4e6..d75e023df637 100644 --- a/drivers/md/dm-vdo/encodings.c +++ b/drivers/md/dm-vdo/encodings.c @@ -287,6 +287,62 @@ static void decode_volume_geometry(u8 *buffer, size_t *offset, }; } +/** + * vdo_encode_volume_geometry() - Encode the on-disk representation of a volume geometry into a buffer. + * @buffer: A buffer to store the encoding. + * @geometry: The geometry to encode. + * @version: The geometry block version to encode. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_encode_volume_geometry(u8 *buffer, const struct volume_geometry *geometry, + u32 version) +{ + int result; + enum volume_region_id id; + u32 checksum; + size_t offset = 0; + const struct header *header; + + memcpy(buffer, VDO_GEOMETRY_MAGIC_NUMBER, VDO_GEOMETRY_MAGIC_NUMBER_SIZE); + offset += VDO_GEOMETRY_MAGIC_NUMBER_SIZE; + + header = (version > 4) ? &GEOMETRY_BLOCK_HEADER_5_0 : &GEOMETRY_BLOCK_HEADER_4_0; + vdo_encode_header(buffer, &offset, header); + + /* This is for backwards compatibility */ + encode_u32_le(buffer, &offset, geometry->unused); + encode_u64_le(buffer, &offset, geometry->nonce); + memcpy(buffer + offset, (unsigned char *) &geometry->uuid, sizeof(uuid_t)); + offset += sizeof(uuid_t); + + if (version > 4) + encode_u64_le(buffer, &offset, geometry->bio_offset); + + for (id = 0; id < VDO_VOLUME_REGION_COUNT; id++) { + encode_u32_le(buffer, &offset, geometry->regions[id].id); + encode_u64_le(buffer, &offset, geometry->regions[id].start_block); + } + + encode_u32_le(buffer, &offset, geometry->index_config.mem); + encode_u32_le(buffer, &offset, 0); + + if (geometry->index_config.sparse) + buffer[offset++] = 1; + else + buffer[offset++] = 0; + + result = VDO_ASSERT(header->size == offset + sizeof(u32), + "should have encoded up to the geometry checksum"); + if (result != VDO_SUCCESS) + return result; + + checksum = vdo_crc32(buffer, offset); + encode_u32_le(buffer, &offset, checksum); + + return VDO_SUCCESS; +} + /** * vdo_parse_geometry_block() - Decode and validate an encoded geometry block. * @block: The encoded geometry block. diff --git a/drivers/md/dm-vdo/encodings.h b/drivers/md/dm-vdo/encodings.h index 0393936c8aeb..67ff0ff2ffda 100644 --- a/drivers/md/dm-vdo/encodings.h +++ b/drivers/md/dm-vdo/encodings.h @@ -813,6 +813,8 @@ int vdo_initialize_volume_geometry(nonce_t nonce, uuid_t *uuid, const struct index_config *index_config, struct volume_geometry *geometry); +int vdo_encode_volume_geometry(u8 *buffer, const struct volume_geometry *geometry, + u32 version); int __must_check vdo_parse_geometry_block(unsigned char *block, struct volume_geometry *geometry); -- 2.52.0
