diff options
Diffstat (limited to 'utils.c')
| -rw-r--r-- | utils.c | 116 |
1 files changed, 116 insertions, 0 deletions
@@ -215,6 +215,97 @@ static int reserve_free_space(struct cache_tree *free_tree, u64 len, return 0; } +static inline int write_temp_super(int fd, struct btrfs_super_block *sb, + u64 sb_bytenr) +{ + u32 crc = ~(u32)0; + int ret; + + crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, crc, + BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); + btrfs_csum_final(crc, (char *)&sb->csum[0]); + ret = pwrite(fd, sb, BTRFS_SUPER_INFO_SIZE, sb_bytenr); + if (ret < BTRFS_SUPER_INFO_SIZE) + ret = (ret < 0 ? -errno : -EIO); + else + ret = 0; + return ret; +} + +/* + * Setup temporary superblock at cfg->super_bynter + * Needed info are extracted from cfg, and root_bytenr, chunk_bytenr + * + * For now sys chunk array will be empty and dev_item is empty too. + * They will be re-initialized at temp chunk tree setup. + */ +static int setup_temp_super(int fd, struct btrfs_mkfs_config *cfg, + u64 root_bytenr, u64 chunk_bytenr) +{ + unsigned char chunk_uuid[BTRFS_UUID_SIZE]; + char super_buf[BTRFS_SUPER_INFO_SIZE]; + struct btrfs_super_block *super = (struct btrfs_super_block *)super_buf; + int ret; + + /* + * We rely on cfg->chunk_uuid and cfg->fs_uuid to pass uuid + * for other functions. + * Caller must allocate space for them + */ + BUG_ON(!cfg->chunk_uuid || !cfg->fs_uuid); + memset(super_buf, 0, BTRFS_SUPER_INFO_SIZE); + cfg->num_bytes = round_down(cfg->num_bytes, cfg->sectorsize); + + if (cfg->fs_uuid && *cfg->fs_uuid) { + if (uuid_parse(cfg->fs_uuid, super->fsid) != 0) { + error("cound not parse UUID: %s", cfg->fs_uuid); + ret = -EINVAL; + goto out; + } + if (!test_uuid_unique(cfg->fs_uuid)) { + error("non-unique UUID: %s", cfg->fs_uuid); + ret = -EINVAL; + goto out; + } + } else { + uuid_generate(super->fsid); + uuid_unparse(super->fsid, cfg->fs_uuid); + } + uuid_generate(chunk_uuid); + uuid_unparse(chunk_uuid, cfg->chunk_uuid); + + btrfs_set_super_bytenr(super, cfg->super_bytenr); + btrfs_set_super_num_devices(super, 1); + btrfs_set_super_magic(super, BTRFS_MAGIC); + btrfs_set_super_generation(super, 1); + btrfs_set_super_root(super, root_bytenr); + btrfs_set_super_chunk_root(super, chunk_bytenr); + btrfs_set_super_total_bytes(super, cfg->num_bytes); + /* + * Temporary filesystem will only have 6 tree roots: + * chunk tree, root tree, extent_tree, device tree, fs tree + * and csum tree. + */ + btrfs_set_super_bytes_used(super, 6 * cfg->nodesize); + btrfs_set_super_sectorsize(super, cfg->sectorsize); + btrfs_set_super_leafsize(super, cfg->nodesize); + btrfs_set_super_nodesize(super, cfg->nodesize); + btrfs_set_super_stripesize(super, cfg->stripesize); + btrfs_set_super_csum_type(super, BTRFS_CSUM_TYPE_CRC32); + btrfs_set_super_chunk_root(super, chunk_bytenr); + btrfs_set_super_cache_generation(super, -1); + btrfs_set_super_incompat_flags(super, cfg->features); + if (cfg->label) + __strncpy_null(super->label, cfg->label, BTRFS_LABEL_SIZE - 1); + + /* Sys chunk array will be re-initialized at chunk tree init time */ + super->sys_chunk_array_size = 0; + + ret = write_temp_super(fd, super, cfg->super_bytenr); +out: + return ret; +} + /* * Improved version of make_btrfs(). * @@ -233,6 +324,10 @@ static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg, struct cache_tree *used = &cctx->used; u64 sys_chunk_start; u64 meta_chunk_start; + /* chunk tree bytenr, in system chunk */ + u64 chunk_bytenr; + /* metadata trees bytenr, in metadata chunk */ + u64 root_bytenr; int ret; /* Shouldn't happen */ @@ -263,6 +358,27 @@ static int make_convert_btrfs(int fd, struct btrfs_mkfs_config *cfg, if (ret < 0) goto out; + /* + * Inside the allocated metadata chunk, the layout will be: + * | offset | contents | + * ------------------------------------- + * | +0 | tree root | + * | +nodesize | extent root | + * | +nodesize * 2 | device root | + * | +nodesize * 3 | fs tree | + * | +nodesize * 4 | csum tree | + * ------------------------------------- + * Inside the allocated system chunk, the layout will be: + * | offset | contents | + * ------------------------------------- + * | +0 | chunk root | + * ------------------------------------- + */ + chunk_bytenr = sys_chunk_start; + root_bytenr = meta_chunk_start; + ret = setup_temp_super(fd, cfg, root_bytenr, chunk_bytenr); + if (ret < 0) + goto out; out: return ret; } |