On Fri, Jan 29, 2016 at 01:03:15PM +0800, Qu Wenruo wrote: > Introduce a new function, setup_temp_super(), to setup temporary super > for make_btrfs_v2(). > > Signed-off-by: Qu Wenruo <[email protected]> > Signed-off-by: David Sterba <[email protected]> > --- > utils.c | 117 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 117 insertions(+) > > diff --git a/utils.c b/utils.c > index bc10293..ed5476d 100644 > --- a/utils.c > +++ b/utils.c > @@ -212,6 +212,98 @@ 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 allocation 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 btrfs will only has 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(super->label, cfg->label, BTRFS_LABEL_SIZE - 1);
Why not use __strncpy_null? Thanks, -liubo > + > + /* 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(). > * > @@ -230,6 +322,10 @@ 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 */ > @@ -260,6 +356,27 @@ static int make_convert_btrfs(int fd, struct > btrfs_mkfs_config *cfg, > if (ret < 0) > goto out; > > + /* > + * Inside the allocate metadata chunk, its 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, its 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; > } > -- > 2.7.0 > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
