Exemplo n.º 1
0
int enable_extrefs_flag(struct btrfs_root *root)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_super_block *disk_super;
	u64 super_flags;

	disk_super = root->fs_info->super_copy;
	super_flags = btrfs_super_incompat_flags(disk_super);
	super_flags |= BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF;
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_super_incompat_flags(disk_super, super_flags);
	btrfs_commit_transaction(trans, root);

	return 0;
}
Exemplo n.º 2
0
static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_super_block *disk_super;
	u64 super_flags;
	int ret;

	disk_super = root->fs_info->super_copy;
	super_flags = btrfs_super_incompat_flags(disk_super);
	super_flags |= flags;
	trans = btrfs_start_transaction(root, 1);
	btrfs_set_super_incompat_flags(disk_super, super_flags);
	ret = btrfs_commit_transaction(trans, root);

	return ret;
}
Exemplo n.º 3
0
static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
					     u64 sb_bytenr,
					     u64 root_tree_bytenr, int writes,
					     int partial)
{
	u32 sectorsize;
	u32 nodesize;
	u32 leafsize;
	u32 blocksize;
	u32 stripesize;
	u64 generation;
	struct btrfs_key key;
	struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root));
	struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root));
	struct btrfs_root *chunk_root = malloc(sizeof(struct btrfs_root));
	struct btrfs_root *dev_root = malloc(sizeof(struct btrfs_root));
	struct btrfs_root *csum_root = malloc(sizeof(struct btrfs_root));
	struct btrfs_fs_info *fs_info = malloc(sizeof(*fs_info));
	int ret;
	struct btrfs_super_block *disk_super;
	struct btrfs_fs_devices *fs_devices = NULL;
	u64 total_devs;
	u64 features;

	if (sb_bytenr == 0)
		sb_bytenr = BTRFS_SUPER_INFO_OFFSET;

	/* try to drop all the caches */
	if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
		fprintf(stderr, "Warning, could not drop caches\n");

	ret = btrfs_scan_one_device(fp, path, &fs_devices,
				    &total_devs, sb_bytenr);

	if (ret) {
		fprintf(stderr, "No valid Btrfs found on %s\n", path);
		goto out;
	}

	if (total_devs != 1) {
		ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1);
		if (ret)
			goto out;
	}

	memset(fs_info, 0, sizeof(*fs_info));
	fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
	fs_info->tree_root = tree_root;
	fs_info->extent_root = extent_root;
	fs_info->chunk_root = chunk_root;
	fs_info->dev_root = dev_root;
	fs_info->csum_root = csum_root;

	if (!writes)
		fs_info->readonly = 1;

	extent_io_tree_init(&fs_info->extent_cache);
	extent_io_tree_init(&fs_info->free_space_cache);
	extent_io_tree_init(&fs_info->block_group_cache);
	extent_io_tree_init(&fs_info->pinned_extents);
	extent_io_tree_init(&fs_info->pending_del);
	extent_io_tree_init(&fs_info->extent_ins);
	cache_tree_init(&fs_info->fs_root_cache);

	cache_tree_init(&fs_info->mapping_tree.cache_tree);

	mutex_init(&fs_info->fs_mutex);
	fs_info->fs_devices = fs_devices;
	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
	INIT_LIST_HEAD(&fs_info->space_info);

	__setup_root(4096, 4096, 4096, 4096, tree_root,
		     fs_info, BTRFS_ROOT_TREE_OBJECTID);

	if (writes)
		ret = btrfs_open_devices(fs_devices, O_RDWR);
	else
		ret = btrfs_open_devices(fs_devices, O_RDONLY);
	if (ret)
		goto out_cleanup;

	fs_info->super_bytenr = sb_bytenr;
	disk_super = fs_info->super_copy;
	ret = btrfs_read_dev_super(fs_devices->latest_bdev,
				   disk_super, sb_bytenr);
	if (ret) {
		printk("No valid btrfs found\n");
		goto out_devices;
	}

	memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);


	features = btrfs_super_incompat_flags(disk_super) &
		   ~BTRFS_FEATURE_INCOMPAT_SUPP;
	if (features) {
		printk("couldn't open because of unsupported "
		       "option features (%Lx).\n",
		       (unsigned long long)features);
		goto out_devices;
	}

	features = btrfs_super_incompat_flags(disk_super);
	if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
		features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
		btrfs_set_super_incompat_flags(disk_super, features);
	}

	features = btrfs_super_compat_ro_flags(disk_super) &
		~BTRFS_FEATURE_COMPAT_RO_SUPP;
	if (writes && features) {
		printk("couldn't open RDWR because of unsupported "
		       "option features (%Lx).\n",
		       (unsigned long long)features);
		goto out_devices;
	}

	nodesize = btrfs_super_nodesize(disk_super);
	leafsize = btrfs_super_leafsize(disk_super);
	sectorsize = btrfs_super_sectorsize(disk_super);
	stripesize = btrfs_super_stripesize(disk_super);
	tree_root->nodesize = nodesize;
	tree_root->leafsize = leafsize;
	tree_root->sectorsize = sectorsize;
	tree_root->stripesize = stripesize;

	ret = btrfs_read_sys_array(tree_root);
	if (ret)
		goto out_devices;
	blocksize = btrfs_level_size(tree_root,
				     btrfs_super_chunk_root_level(disk_super));
	generation = btrfs_super_chunk_root_generation(disk_super);

	__setup_root(nodesize, leafsize, sectorsize, stripesize,
		     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);

	chunk_root->node = read_tree_block(chunk_root,
					   btrfs_super_chunk_root(disk_super),
					   blocksize, generation);
	if (!extent_buffer_uptodate(chunk_root->node)) {
		printk("Couldn't read chunk root\n");
		goto out_devices;
	}

	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
	         (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
		 BTRFS_UUID_SIZE);

	if (!(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)) {
		ret = btrfs_read_chunk_tree(chunk_root);
		if (ret) {
			printk("Couldn't read chunk tree\n");
			goto out_chunk;
		}
	}

	blocksize = btrfs_level_size(tree_root,
				     btrfs_super_root_level(disk_super));
	generation = btrfs_super_generation(disk_super);

	if (!root_tree_bytenr)
		root_tree_bytenr = btrfs_super_root(disk_super);
	tree_root->node = read_tree_block(tree_root,
					  root_tree_bytenr,
					  blocksize, generation);
	if (!extent_buffer_uptodate(tree_root->node)) {
		printk("Couldn't read tree root\n");
		goto out_failed;
	}
	ret = find_and_setup_root(tree_root, fs_info,
				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
	if (ret) {
		printk("Couldn't setup extent tree\n");
		goto out_failed;
	}
	extent_root->track_dirty = 1;

	ret = find_and_setup_root(tree_root, fs_info,
				  BTRFS_DEV_TREE_OBJECTID, dev_root);
	if (ret) {
		printk("Couldn't setup device tree\n");
		goto out_failed;
	}
	dev_root->track_dirty = 1;

	ret = find_and_setup_root(tree_root, fs_info,
				  BTRFS_CSUM_TREE_OBJECTID, csum_root);
	if (ret) {
		printk("Couldn't setup csum tree\n");
		if (!partial)
			goto out_failed;
	}
	csum_root->track_dirty = 1;

	find_and_setup_log_root(tree_root, fs_info, disk_super);

	fs_info->generation = generation;
	fs_info->last_trans_committed = generation;
	btrfs_read_block_groups(fs_info->tree_root);

	key.objectid = BTRFS_FS_TREE_OBJECTID;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;
	fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);

	if (!fs_info->fs_root)
		goto out_failed;

	fs_info->data_alloc_profile = (u64)-1;
	fs_info->metadata_alloc_profile = (u64)-1;
	fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;

	return fs_info;

out_failed:
	if (partial)
		return fs_info;

	if (fs_info->csum_root)
		free_extent_buffer(fs_info->csum_root->node);
	if (fs_info->dev_root)
		free_extent_buffer(fs_info->dev_root->node);
	if (fs_info->extent_root)
		free_extent_buffer(fs_info->extent_root->node);
	if (fs_info->tree_root)
		free_extent_buffer(fs_info->tree_root->node);
out_chunk:
	if (fs_info->chunk_root)
		free_extent_buffer(fs_info->chunk_root->node);
out_devices:
	close_all_devices(fs_info);
out_cleanup:
	extent_io_tree_cleanup(&fs_info->extent_cache);
	extent_io_tree_cleanup(&fs_info->free_space_cache);
	extent_io_tree_cleanup(&fs_info->block_group_cache);
	extent_io_tree_cleanup(&fs_info->pinned_extents);
	extent_io_tree_cleanup(&fs_info->pending_del);
	extent_io_tree_cleanup(&fs_info->extent_ins);
out:
	free(tree_root);
	free(extent_root);
	free(chunk_root);
	free(dev_root);
	free(csum_root);
	free(fs_info);
	return NULL;
}
Exemplo n.º 4
0
int make_btrfs(int fd, const char *device, const char *label,
	       u64 blocks[7], u64 num_bytes, u32 nodesize,
	       u32 leafsize, u32 sectorsize, u32 stripesize, u64 features)
{
	struct btrfs_super_block super;
	struct extent_buffer *buf;
	struct btrfs_root_item root_item;
	struct btrfs_disk_key disk_key;
	struct btrfs_extent_item *extent_item;
	struct btrfs_inode_item *inode_item;
	struct btrfs_chunk *chunk;
	struct btrfs_dev_item *dev_item;
	struct btrfs_dev_extent *dev_extent;
	u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
	u8 *ptr;
	int i;
	int ret;
	u32 itemoff;
	u32 nritems = 0;
	u64 first_free;
	u64 ref_root;
	u32 array_size;
	u32 item_size;
	int skinny_metadata = !!(features &
				 BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA);

	first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
	first_free &= ~((u64)sectorsize - 1);

	memset(&super, 0, sizeof(super));

	num_bytes = (num_bytes / sectorsize) * sectorsize;
	uuid_generate(super.fsid);
	uuid_generate(super.dev_item.uuid);
	uuid_generate(chunk_tree_uuid);

	btrfs_set_super_bytenr(&super, blocks[0]);
	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, blocks[1]);
	btrfs_set_super_chunk_root(&super, blocks[3]);
	btrfs_set_super_total_bytes(&super, num_bytes);
	btrfs_set_super_bytes_used(&super, 6 * leafsize);
	btrfs_set_super_sectorsize(&super, sectorsize);
	btrfs_set_super_leafsize(&super, leafsize);
	btrfs_set_super_nodesize(&super, nodesize);
	btrfs_set_super_stripesize(&super, stripesize);
	btrfs_set_super_csum_type(&super, BTRFS_CSUM_TYPE_CRC32);
	btrfs_set_super_chunk_root_generation(&super, 1);
	btrfs_set_super_cache_generation(&super, -1);
	btrfs_set_super_incompat_flags(&super, features);
	if (label)
		strncpy(super.label, label, BTRFS_LABEL_SIZE - 1);

	buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));

	/* create the tree of root objects */
	memset(buf->data, 0, leafsize);
	buf->len = leafsize;
	btrfs_set_header_bytenr(buf, blocks[1]);
	btrfs_set_header_nritems(buf, 4);
	btrfs_set_header_generation(buf, 1);
	btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV);
	btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
	write_extent_buffer(buf, super.fsid, btrfs_header_fsid(),
			    BTRFS_FSID_SIZE);

	write_extent_buffer(buf, chunk_tree_uuid, (unsigned long)
			    btrfs_header_chunk_tree_uuid(buf),
			    BTRFS_UUID_SIZE);

	/* create the items for the root tree */
	memset(&root_item, 0, sizeof(root_item));
	inode_item = &root_item.inode;
	btrfs_set_stack_inode_generation(inode_item, 1);
	btrfs_set_stack_inode_size(inode_item, 3);
	btrfs_set_stack_inode_nlink(inode_item, 1);
	btrfs_set_stack_inode_nbytes(inode_item, leafsize);
	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
	btrfs_set_root_refs(&root_item, 1);
	btrfs_set_root_used(&root_item, leafsize);
	btrfs_set_root_generation(&root_item, 1);

	memset(&disk_key, 0, sizeof(disk_key));
	btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
	btrfs_set_disk_key_offset(&disk_key, 0);
	nritems = 0;

	itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
	btrfs_set_root_bytenr(&root_item, blocks[2]);
	btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems),
			    sizeof(root_item));
	write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf,
			    nritems), sizeof(root_item));
	nritems++;

	itemoff = itemoff - sizeof(root_item);
	btrfs_set_root_bytenr(&root_item, blocks[4]);
	btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_TREE_OBJECTID);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems),
			    sizeof(root_item));
	write_extent_buffer(buf, &root_item,
			    btrfs_item_ptr_offset(buf, nritems),
			    sizeof(root_item));
	nritems++;

	itemoff = itemoff - sizeof(root_item);
	btrfs_set_root_bytenr(&root_item, blocks[5]);
	btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems),
			    sizeof(root_item));
	write_extent_buffer(buf, &root_item,
			    btrfs_item_ptr_offset(buf, nritems),
			    sizeof(root_item));
	nritems++;

	itemoff = itemoff - sizeof(root_item);
	btrfs_set_root_bytenr(&root_item, blocks[6]);
	btrfs_set_disk_key_objectid(&disk_key, BTRFS_CSUM_TREE_OBJECTID);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems),
			    sizeof(root_item));
	write_extent_buffer(buf, &root_item,
			    btrfs_item_ptr_offset(buf, nritems),
			    sizeof(root_item));
	nritems++;


	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, leafsize, blocks[1]);
	if (ret != leafsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}

	/* create the items for the extent tree */
	memset(buf->data+sizeof(struct btrfs_header), 0,
		leafsize-sizeof(struct btrfs_header));
	nritems = 0;
	itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize);
	for (i = 1; i < 7; i++) {
		item_size = sizeof(struct btrfs_extent_item);
		if (!skinny_metadata)
			item_size += sizeof(struct btrfs_tree_block_info);

		BUG_ON(blocks[i] < first_free);
		BUG_ON(blocks[i] < blocks[i - 1]);

		/* create extent item */
		itemoff -= item_size;
		btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
		if (skinny_metadata) {
			btrfs_set_disk_key_type(&disk_key,
						BTRFS_METADATA_ITEM_KEY);
			btrfs_set_disk_key_offset(&disk_key, 0);
		} else {
			btrfs_set_disk_key_type(&disk_key,
						BTRFS_EXTENT_ITEM_KEY);
			btrfs_set_disk_key_offset(&disk_key, leafsize);
		}
		btrfs_set_item_key(buf, &disk_key, nritems);
		btrfs_set_item_offset(buf, btrfs_item_nr(nritems),
				      itemoff);
		btrfs_set_item_size(buf, btrfs_item_nr(nritems),
				    item_size);
		extent_item = btrfs_item_ptr(buf, nritems,
					     struct btrfs_extent_item);
		btrfs_set_extent_refs(buf, extent_item, 1);
		btrfs_set_extent_generation(buf, extent_item, 1);
		btrfs_set_extent_flags(buf, extent_item,
				       BTRFS_EXTENT_FLAG_TREE_BLOCK);
		nritems++;

		/* create extent ref */
		ref_root = reference_root_table[i];
		btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
		btrfs_set_disk_key_offset(&disk_key, ref_root);
		btrfs_set_disk_key_type(&disk_key, BTRFS_TREE_BLOCK_REF_KEY);
		btrfs_set_item_key(buf, &disk_key, nritems);
		btrfs_set_item_offset(buf, btrfs_item_nr(nritems),
				      itemoff);
		btrfs_set_item_size(buf, btrfs_item_nr(nritems), 0);
		nritems++;
	}
	btrfs_set_header_bytenr(buf, blocks[2]);
	btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
	btrfs_set_header_nritems(buf, nritems);
	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, leafsize, blocks[2]);
	if (ret != leafsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}

	/* create the chunk tree */
	memset(buf->data+sizeof(struct btrfs_header), 0,
		leafsize-sizeof(struct btrfs_header));
	nritems = 0;
	item_size = sizeof(*dev_item);
	itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - item_size;

	/* first device 1 (there is no device 0) */
	btrfs_set_disk_key_objectid(&disk_key, BTRFS_DEV_ITEMS_OBJECTID);
	btrfs_set_disk_key_offset(&disk_key, 1);
	btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_ITEM_KEY);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems), item_size);

	dev_item = btrfs_item_ptr(buf, nritems, struct btrfs_dev_item);
	btrfs_set_device_id(buf, dev_item, 1);
	btrfs_set_device_generation(buf, dev_item, 0);
	btrfs_set_device_total_bytes(buf, dev_item, num_bytes);
	btrfs_set_device_bytes_used(buf, dev_item,
				    BTRFS_MKFS_SYSTEM_GROUP_SIZE);
	btrfs_set_device_io_align(buf, dev_item, sectorsize);
	btrfs_set_device_io_width(buf, dev_item, sectorsize);
	btrfs_set_device_sector_size(buf, dev_item, sectorsize);
	btrfs_set_device_type(buf, dev_item, 0);

	write_extent_buffer(buf, super.dev_item.uuid,
			    (unsigned long)btrfs_device_uuid(dev_item),
			    BTRFS_UUID_SIZE);
	write_extent_buffer(buf, super.fsid,
			    (unsigned long)btrfs_device_fsid(dev_item),
			    BTRFS_UUID_SIZE);
	read_extent_buffer(buf, &super.dev_item, (unsigned long)dev_item,
			   sizeof(*dev_item));

	nritems++;
	item_size = btrfs_chunk_item_size(1);
	itemoff = itemoff - item_size;

	/* then we have chunk 0 */
	btrfs_set_disk_key_objectid(&disk_key, BTRFS_FIRST_CHUNK_TREE_OBJECTID);
	btrfs_set_disk_key_offset(&disk_key, 0);
	btrfs_set_disk_key_type(&disk_key, BTRFS_CHUNK_ITEM_KEY);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems), item_size);

	chunk = btrfs_item_ptr(buf, nritems, struct btrfs_chunk);
	btrfs_set_chunk_length(buf, chunk, BTRFS_MKFS_SYSTEM_GROUP_SIZE);
	btrfs_set_chunk_owner(buf, chunk, BTRFS_EXTENT_TREE_OBJECTID);
	btrfs_set_chunk_stripe_len(buf, chunk, 64 * 1024);
	btrfs_set_chunk_type(buf, chunk, BTRFS_BLOCK_GROUP_SYSTEM);
	btrfs_set_chunk_io_align(buf, chunk, sectorsize);
	btrfs_set_chunk_io_width(buf, chunk, sectorsize);
	btrfs_set_chunk_sector_size(buf, chunk, sectorsize);
	btrfs_set_chunk_num_stripes(buf, chunk, 1);
	btrfs_set_stripe_devid_nr(buf, chunk, 0, 1);
	btrfs_set_stripe_offset_nr(buf, chunk, 0, 0);
	nritems++;

	write_extent_buffer(buf, super.dev_item.uuid,
			    (unsigned long)btrfs_stripe_dev_uuid(&chunk->stripe),
			    BTRFS_UUID_SIZE);

	/* copy the key for the chunk to the system array */
	ptr = super.sys_chunk_array;
	array_size = sizeof(disk_key);

	memcpy(ptr, &disk_key, sizeof(disk_key));
	ptr += sizeof(disk_key);

	/* copy the chunk to the system array */
	read_extent_buffer(buf, ptr, (unsigned long)chunk, item_size);
	array_size += item_size;
	ptr += item_size;
	btrfs_set_super_sys_array_size(&super, array_size);

	btrfs_set_header_bytenr(buf, blocks[3]);
	btrfs_set_header_owner(buf, BTRFS_CHUNK_TREE_OBJECTID);
	btrfs_set_header_nritems(buf, nritems);
	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, leafsize, blocks[3]);
	if (ret != leafsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}

	/* create the device tree */
	memset(buf->data+sizeof(struct btrfs_header), 0,
		leafsize-sizeof(struct btrfs_header));
	nritems = 0;
	itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
		sizeof(struct btrfs_dev_extent);

	btrfs_set_disk_key_objectid(&disk_key, 1);
	btrfs_set_disk_key_offset(&disk_key, 0);
	btrfs_set_disk_key_type(&disk_key, BTRFS_DEV_EXTENT_KEY);
	btrfs_set_item_key(buf, &disk_key, nritems);
	btrfs_set_item_offset(buf, btrfs_item_nr(nritems), itemoff);
	btrfs_set_item_size(buf, btrfs_item_nr(nritems),
			    sizeof(struct btrfs_dev_extent));
	dev_extent = btrfs_item_ptr(buf, nritems, struct btrfs_dev_extent);
	btrfs_set_dev_extent_chunk_tree(buf, dev_extent,
					BTRFS_CHUNK_TREE_OBJECTID);
	btrfs_set_dev_extent_chunk_objectid(buf, dev_extent,
					BTRFS_FIRST_CHUNK_TREE_OBJECTID);
	btrfs_set_dev_extent_chunk_offset(buf, dev_extent, 0);

	write_extent_buffer(buf, chunk_tree_uuid,
		    (unsigned long)btrfs_dev_extent_chunk_tree_uuid(dev_extent),
		    BTRFS_UUID_SIZE);

	btrfs_set_dev_extent_length(buf, dev_extent,
				    BTRFS_MKFS_SYSTEM_GROUP_SIZE);
	nritems++;

	btrfs_set_header_bytenr(buf, blocks[4]);
	btrfs_set_header_owner(buf, BTRFS_DEV_TREE_OBJECTID);
	btrfs_set_header_nritems(buf, nritems);
	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, leafsize, blocks[4]);
	if (ret != leafsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}

	/* create the FS root */
	memset(buf->data+sizeof(struct btrfs_header), 0,
		leafsize-sizeof(struct btrfs_header));
	btrfs_set_header_bytenr(buf, blocks[5]);
	btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
	btrfs_set_header_nritems(buf, 0);
	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, leafsize, blocks[5]);
	if (ret != leafsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}
	/* finally create the csum root */
	memset(buf->data+sizeof(struct btrfs_header), 0,
		leafsize-sizeof(struct btrfs_header));
	btrfs_set_header_bytenr(buf, blocks[6]);
	btrfs_set_header_owner(buf, BTRFS_CSUM_TREE_OBJECTID);
	btrfs_set_header_nritems(buf, 0);
	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, leafsize, blocks[6]);
	if (ret != leafsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}

	/* and write out the super block */
	BUG_ON(sizeof(super) > sectorsize);
	memset(buf->data, 0, sectorsize);
	memcpy(buf->data, &super, sizeof(super));
	buf->len = sectorsize;
	csum_tree_block_size(buf, BTRFS_CRC32_SIZE, 0);
	ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
	if (ret != sectorsize) {
		ret = (ret < 0 ? -errno : -EIO);
		goto out;
	}

	ret = 0;

out:
	free(buf);
	return ret;
}