static int print_dir_item(struct extent_buffer *eb, struct btrfs_item *item,
			  struct btrfs_dir_item *di)
{
	u32 total;
	u32 cur = 0;
	u32 len;
	u32 name_len;
	u32 data_len;
	char namebuf[BTRFS_NAME_LEN];
	struct btrfs_disk_key location;

	total = btrfs_item_size(eb, item);
	while(cur < total) {
		btrfs_dir_item_key(eb, di, &location);
		printf("\t\tlocation ");
		btrfs_print_key(&location);
		printf(" type %u\n", btrfs_dir_type(eb, di));
		name_len = btrfs_dir_name_len(eb, di);
		data_len = btrfs_dir_data_len(eb, di);
		len = (name_len <= sizeof(namebuf))? name_len: sizeof(namebuf);
		read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), len);
		printf("\t\tnamelen %u datalen %u name: %.*s\n",
		       name_len, data_len, len, namebuf);
		if (data_len) {
			len = (data_len <= sizeof(namebuf))? data_len: sizeof(namebuf);
			read_extent_buffer(eb, namebuf,
				(unsigned long)(di + 1) + name_len, len);
			printf("\t\tdata %.*s\n", len, namebuf);
		}
		len = sizeof(*di) + name_len + data_len;
		di = (struct btrfs_dir_item *)((char *)di + len);
		cur += len;
	}
	return 0;
}

void print_chunk(struct extent_buffer *eb, struct btrfs_chunk *chunk)
{
	int num_stripes = btrfs_chunk_num_stripes(eb, chunk);
	int i;
	char chunk_flags_str[32] = {0};

	bg_flags_to_str(btrfs_chunk_type(eb, chunk), chunk_flags_str);
	printf("\t\tlength %llu owner %llu stripe_len %llu type %s\n",
	       (unsigned long long)btrfs_chunk_length(eb, chunk),
	       (unsigned long long)btrfs_chunk_owner(eb, chunk),
	       (unsigned long long)btrfs_chunk_stripe_len(eb, chunk),
		chunk_flags_str);
	printf("\t\tio_align %u io_width %u sector_size %u\n",
			btrfs_chunk_io_align(eb, chunk),
			btrfs_chunk_io_width(eb, chunk),
			btrfs_chunk_sector_size(eb, chunk));
	printf("\t\tnum_stripes %hu sub_stripes %hu\n", num_stripes,
			btrfs_chunk_sub_stripes(eb, chunk));
	for (i = 0 ; i < num_stripes ; i++) {
		unsigned char dev_uuid[BTRFS_UUID_SIZE];
		char str_dev_uuid[BTRFS_UUID_UNPARSED_SIZE];

		read_extent_buffer(eb, dev_uuid,
			(unsigned long)btrfs_stripe_dev_uuid_nr(chunk, i),
			BTRFS_UUID_SIZE);
		uuid_unparse(dev_uuid, str_dev_uuid);
		printf("\t\t\tstripe %d devid %llu offset %llu\n", i,
		      (unsigned long long)btrfs_stripe_devid_nr(eb, chunk, i),
		      (unsigned long long)btrfs_stripe_offset_nr(eb, chunk, i));
		printf("\t\t\tdev_uuid %s\n", str_dev_uuid);
	}
}

static int print_inode_extref_item(struct extent_buffer *eb,
				   struct btrfs_item *item,
				   struct btrfs_inode_extref *extref)
{
	u32 total;
	u32 cur = 0;
	u32 len;
	u32 name_len = 0;
	u64 index = 0;
	u64 parent_objid;
	char namebuf[BTRFS_NAME_LEN];

	total = btrfs_item_size(eb, item);

	while (cur < total) {
		index = btrfs_inode_extref_index(eb, extref);
		name_len = btrfs_inode_extref_name_len(eb, extref);
		parent_objid = btrfs_inode_extref_parent(eb, extref);

		len = (name_len <= sizeof(namebuf))? name_len: sizeof(namebuf);

		read_extent_buffer(eb, namebuf, (unsigned long)(extref->name), len);

		printf("\t\tinode extref index %llu parent %llu namelen %u "
		       "name: %.*s\n",
		       (unsigned long long)index,
		       (unsigned long long)parent_objid,
		       name_len, len, namebuf);

		len = sizeof(*extref) + name_len;
		extref = (struct btrfs_inode_extref *)((char *)extref + len);
		cur += len;
	}
	return 0;
}

struct btrfs_root *btrfs_read_fs_root_no_cache(struct btrfs_fs_info *fs_info,
					       struct btrfs_key *location)
{
	struct btrfs_root *root;
	struct btrfs_root *tree_root = fs_info->tree_root;
	struct btrfs_path *path;
	struct extent_buffer *l;
	u64 generation;
	u32 blocksize;
	int ret = 0;

	root = malloc(sizeof(*root));
	if (!root)
		return ERR_PTR(-ENOMEM);
	memset(root, 0, sizeof(*root));
	if (location->offset == (u64)-1) {
		ret = find_and_setup_root(tree_root, fs_info,
					  location->objectid, root);
		if (ret) {
			free(root);
			return ERR_PTR(ret);
		}
		goto insert;
	}

	__setup_root(tree_root->nodesize, tree_root->leafsize,
		     tree_root->sectorsize, tree_root->stripesize,
		     root, fs_info, location->objectid);

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
	if (ret != 0) {
		if (ret > 0)
			ret = -ENOENT;
		goto out;
	}
	l = path->nodes[0];
	read_extent_buffer(l, &root->root_item,
	       btrfs_item_ptr_offset(l, path->slots[0]),
	       sizeof(root->root_item));
	memcpy(&root->root_key, location, sizeof(*location));
	ret = 0;
out:
	btrfs_release_path(root, path);
	btrfs_free_path(path);
	if (ret) {
		free(root);
		return ERR_PTR(ret);
	}
	generation = btrfs_root_generation(&root->root_item);
	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
				     blocksize, generation);
	BUG_ON(!root->node);
insert:
	root->ref_cows = 1;
	return root;
}

/*
 * this iterates to turn a name (from iref/extref) into a full filesystem path.
 * Elements of the path are separated by '/' and the path is guaranteed to be
 * 0-terminated. the path is only given within the current file system.
 * Therefore, it never starts with a '/'. the caller is responsible to provide
 * "size" bytes in "dest". the dest buffer will be filled backwards. finally,
 * the start point of the resulting string is returned. this pointer is within
 * dest, normally.
 * in case the path buffer would overflow, the pointer is decremented further
 * as if output was written to the buffer, though no more output is actually
 * generated. that way, the caller can determine how much space would be
 * required for the path to fit into the buffer. in that case, the returned
 * value will be smaller than dest. callers must check this!
 */
char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
			u32 name_len, unsigned long name_off,
			struct extent_buffer *eb_in, u64 parent,
			char *dest, u32 size)
{
	int slot;
	u64 next_inum;
	int ret;
	s64 bytes_left = ((s64)size) - 1;
	struct extent_buffer *eb = eb_in;
	struct btrfs_key found_key;
	struct btrfs_inode_ref *iref;

	if (bytes_left >= 0)
		dest[bytes_left] = '\0';

	while (1) {
		bytes_left -= name_len;
		if (bytes_left >= 0)
			read_extent_buffer(eb, dest + bytes_left,
					   name_off, name_len);
		if (eb != eb_in)
			free_extent_buffer(eb);
		ret = inode_ref_info(parent, 0, fs_root, path, &found_key);
		if (ret > 0)
			ret = -ENOENT;
		if (ret)
			break;

		next_inum = found_key.offset;

		/* regular exit ahead */
		if (parent == next_inum)
			break;

		slot = path->slots[0];
		eb = path->nodes[0];
		/* make sure we can use eb after releasing the path */
		if (eb != eb_in)
			eb->refs++;
		btrfs_release_path(path);
		iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);

		name_len = btrfs_inode_ref_name_len(eb, iref);
		name_off = (unsigned long)(iref + 1);

		parent = next_inum;
		--bytes_left;
		if (bytes_left >= 0)
			dest[bytes_left] = '/';
	}

	btrfs_release_path(path);

	if (ret)
		return ERR_PTR(ret);

	return dest + bytes_left;
}

/* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */
static int btrfs_uuid_tree_lookup(struct btrfs_root *uuid_root, u8 *uuid,
				  u8 type, u64 subid)
{
	int ret;
	struct btrfs_path *path = NULL;
	struct extent_buffer *eb;
	int slot;
	u32 item_size;
	unsigned long offset;
	struct btrfs_key key;

	if (WARN_ON_ONCE(!uuid_root)) {
		ret = -ENOENT;
		goto out;
	}

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	btrfs_uuid_to_key(uuid, type, &key);
	ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0);
	if (ret < 0) {
		goto out;
	} else if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	eb = path->nodes[0];
	slot = path->slots[0];
	item_size = btrfs_item_size_nr(eb, slot);
	offset = btrfs_item_ptr_offset(eb, slot);
	ret = -ENOENT;

	if (!IS_ALIGNED(item_size, sizeof(u64))) {
		btrfs_warn(uuid_root->fs_info,
			   "uuid item with illegal size %lu!",
			   (unsigned long)item_size);
		goto out;
	}
	while (item_size) {
		__le64 data;

		read_extent_buffer(eb, &data, offset, sizeof(data));
		if (le64_to_cpu(data) == subid) {
			ret = 0;
			break;
		}
		offset += sizeof(data);
		item_size -= sizeof(data);
	}

out:
	btrfs_free_path(path);
	return ret;
}

static int copy_one_inline(struct btrfs_root *root, int fd,
				struct btrfs_path *path, u64 pos)
{
	struct extent_buffer *leaf = path->nodes[0];
	struct btrfs_file_extent_item *fi;
	char buf[4096];
	char *outbuf;
	u64 ram_size;
	ssize_t done;
	unsigned long ptr;
	int ret;
	int len;
	int inline_item_len;
	int compress;

	fi = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
	ptr = btrfs_file_extent_inline_start(fi);
	len = btrfs_file_extent_ram_bytes(leaf, fi);
	inline_item_len = btrfs_file_extent_inline_item_len(leaf, btrfs_item_nr(path->slots[0]));
	read_extent_buffer(leaf, buf, ptr, inline_item_len);

	compress = btrfs_file_extent_compression(leaf, fi);
	if (compress == BTRFS_COMPRESS_NONE) {
		done = pwrite(fd, buf, len, pos);
		if (done < len) {
			fprintf(stderr, "Short inline write, wanted %d, did "
				"%zd: %d\n", len, done, errno);
			return -1;
		}
		return 0;
	}

	ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
	outbuf = calloc(1, ram_size);
	if (!outbuf) {
		error("not enough memory");
		return -ENOMEM;
	}

	ret = decompress(root, buf, outbuf, inline_item_len, &ram_size,
			 compress);
	if (ret) {
		free(outbuf);
		return ret;
	}

	done = pwrite(fd, outbuf, ram_size, pos);
	free(outbuf);
	if (done < ram_size) {
		fprintf(stderr, "Short compressed inline write, wanted %Lu, "
			"did %zd: %d\n", ram_size, done, errno);
		return -1;
	}

	return 0;
}

static struct btrfs_root *open_ctree_broken(int fd, const char *device)
{
	struct btrfs_fs_info *fs_info;
	struct btrfs_super_block *disk_super;
	struct btrfs_fs_devices *fs_devices = NULL;
	struct extent_buffer *eb;
	int ret;

	fs_info = btrfs_new_fs_info(0, BTRFS_SUPER_INFO_OFFSET);
	if (!fs_info) {
		fprintf(stderr, "Failed to allocate memory for fs_info\n");
		return NULL;
	}

	ret = btrfs_scan_fs_devices(fd, device, &fs_devices, 0, 1);
	if (ret)
		goto out;

	fs_info->fs_devices = fs_devices;

	ret = btrfs_open_devices(fs_devices, O_RDONLY);
	if (ret)
		goto out_devices;

	disk_super = fs_info->super_copy;
	ret = btrfs_read_dev_super(fs_devices->latest_bdev,
				   disk_super, fs_info->super_bytenr, 1);
	if (ret) {
		printk("No valid btrfs found\n");
		goto out_devices;
	}

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

	ret = btrfs_check_fs_compatibility(disk_super, 0);
	if (ret)
		goto out_devices;

	ret = btrfs_setup_chunk_tree_and_device_map(fs_info);
	if (ret)
		goto out_chunk;

	eb = fs_info->chunk_root->node;
	read_extent_buffer(eb, fs_info->chunk_tree_uuid,
			   btrfs_header_chunk_tree_uuid(eb), BTRFS_UUID_SIZE);

	return fs_info->chunk_root;
out_chunk:
	free_extent_buffer(fs_info->chunk_root->node);
	btrfs_cleanup_all_caches(fs_info);
out_devices:
	btrfs_close_devices(fs_info->fs_devices);
out:
	btrfs_free_fs_info(fs_info);
	return NULL;
}

ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
				void *buffer, size_t size)
{
	struct btrfs_dir_item *di;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	int ret = 0;
	unsigned long data_ptr;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	/* lookup the xattr by name */
	di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
				strlen(name), 0);
	if (!di) {
		ret = -ENODATA;
		goto out;
	} else if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto out;
	}

	leaf = path->nodes[0];
	/* if size is 0, that means we want the size of the attr */
	if (!size) {
		ret = btrfs_dir_data_len(leaf, di);
		goto out;
	}

	/* now get the data out of our dir_item */
	if (btrfs_dir_data_len(leaf, di) > size) {
		ret = -ERANGE;
		goto out;
	}

	/*
	 * The way things are packed into the leaf is like this
	 * |struct btrfs_dir_item|name|data|
	 * where name is the xattr name, so security.foo, and data is the
	 * content of the xattr.  data_ptr points to the location in memory
	 * where the data starts in the in memory leaf
	 */
	data_ptr = (unsigned long)((char *)(di + 1) +
				   btrfs_dir_name_len(leaf, di));
	read_extent_buffer(leaf, buffer, data_ptr,
			   btrfs_dir_data_len(leaf, di));
	ret = btrfs_dir_data_len(leaf, di);

out:
	btrfs_free_path(path);
	return ret;
}

ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
				void *buffer, size_t size)
{
	struct btrfs_dir_item *di;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	int ret = 0;
	unsigned long data_ptr;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	/*                          */
	di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
				strlen(name), 0);
	if (!di) {
		ret = -ENODATA;
		goto out;
	} else if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto out;
	}

	leaf = path->nodes[0];
	/*                                                       */
	if (!size) {
		ret = btrfs_dir_data_len(leaf, di);
		goto out;
	}

	/*                                      */
	if (btrfs_dir_data_len(leaf, di) > size) {
		ret = -ERANGE;
		goto out;
	}

	/*
                                                        
                                     
                                                                  
                                                                    
                                               
  */
	data_ptr = (unsigned long)((char *)(di + 1) +
				   btrfs_dir_name_len(leaf, di));
	read_extent_buffer(leaf, buffer, data_ptr,
			   btrfs_dir_data_len(leaf, di));
	ret = btrfs_dir_data_len(leaf, di);

out:
	btrfs_free_path(path);
	return ret;
}

static void print_uuids(struct extent_buffer *eb)
{
	char fs_uuid[37];
	char chunk_uuid[37];
	u8 disk_uuid[BTRFS_UUID_SIZE];

	read_extent_buffer(eb, disk_uuid, (unsigned long)btrfs_header_fsid(eb),
			   BTRFS_FSID_SIZE);

	fs_uuid[36] = '\0';
	uuid_unparse(disk_uuid, fs_uuid);

	read_extent_buffer(eb, disk_uuid,
			   (unsigned long)btrfs_header_chunk_tree_uuid(eb),
			   BTRFS_UUID_SIZE);

	chunk_uuid[36] = '\0';
	uuid_unparse(disk_uuid, chunk_uuid);
	printf("fs uuid %s\nchunk uuid %s\n", fs_uuid, chunk_uuid);
}

static void print_root(struct extent_buffer *leaf, int slot)
{
	struct btrfs_root_item *ri;
	struct btrfs_root_item root_item;
	int len;
	char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
	char flags_str[32] = {0};
	struct btrfs_key drop_key;

	ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
	len = btrfs_item_size_nr(leaf, slot);

	memset(&root_item, 0, sizeof(root_item));
	read_extent_buffer(leaf, &root_item, (unsigned long)ri, len);
	root_flags_to_str(btrfs_root_flags(&root_item), flags_str);

	printf("\t\tgeneration %llu root_dirid %llu bytenr %llu level %hhu refs %u\n",
		(unsigned long long)btrfs_root_generation(&root_item),
		(unsigned long long)btrfs_root_dirid(&root_item),
		(unsigned long long)btrfs_root_bytenr(&root_item),
		btrfs_root_level(&root_item),
		btrfs_root_refs(&root_item));
	printf("\t\tlastsnap %llu byte_limit %llu bytes_used %llu flags 0x%llx(%s)\n",
		(unsigned long long)btrfs_root_last_snapshot(&root_item),
		(unsigned long long)btrfs_root_limit(&root_item),
		(unsigned long long)btrfs_root_used(&root_item),
		(unsigned long long)btrfs_root_flags(&root_item),
		flags_str);

	if (root_item.generation == root_item.generation_v2) {
		uuid_unparse(root_item.uuid, uuid_str);
		printf("\t\tuuid %s\n", uuid_str);
		if (!empty_uuid(root_item.parent_uuid)) {
			uuid_unparse(root_item.parent_uuid, uuid_str);
			printf("\t\tparent_uuid %s\n", uuid_str);
		}
		if (!empty_uuid(root_item.received_uuid)) {
			uuid_unparse(root_item.received_uuid, uuid_str);
			printf("\t\treceived_uuid %s\n", uuid_str);
		}
		if (root_item.ctransid) {
			printf("\t\tctransid %llu otransid %llu stransid %llu rtransid %llu\n",
				btrfs_root_ctransid(&root_item),
				btrfs_root_otransid(&root_item),
				btrfs_root_stransid(&root_item),
				btrfs_root_rtransid(&root_item));
		}
	}

	btrfs_disk_key_to_cpu(&drop_key, &root_item.drop_progress);
	printf("\t\tdrop ");
	btrfs_print_key(&root_item.drop_progress);
	printf(" level %hhu\n", root_item.drop_level);
}

static void print_root_ref(struct extent_buffer *leaf, int slot, char *tag)
{
	struct btrfs_root_ref *ref;
	char namebuf[BTRFS_NAME_LEN];
	int namelen;

	ref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
	namelen = btrfs_root_ref_name_len(leaf, ref);
	read_extent_buffer(leaf, namebuf, (unsigned long)(ref + 1), namelen);
	printf("\t\troot %s key dirid %llu sequence %llu name %.*s\n", tag,
	       (unsigned long long)btrfs_root_ref_dirid(leaf, ref),
	       (unsigned long long)btrfs_root_ref_sequence(leaf, ref),
	       namelen, namebuf);
}

static void print_dev_item(struct extent_buffer *eb,
			   struct btrfs_dev_item *dev_item)
{
	char uuid_str[BTRFS_UUID_UNPARSED_SIZE];
	char fsid_str[BTRFS_UUID_UNPARSED_SIZE];
	u8 uuid[BTRFS_UUID_SIZE];
	u8 fsid[BTRFS_UUID_SIZE];

	read_extent_buffer(eb, uuid,
			   (unsigned long)btrfs_device_uuid(dev_item),
			   BTRFS_UUID_SIZE);
	uuid_unparse(uuid, uuid_str);
	read_extent_buffer(eb, fsid,
			   (unsigned long)btrfs_device_fsid(dev_item),
			   BTRFS_UUID_SIZE);
	uuid_unparse(fsid, fsid_str);
	printf("\t\tdevid %llu total_bytes %llu bytes_used %Lu\n"
	       "\t\tio_align %u io_width %u sector_size %u type %llu\n"
	       "\t\tgeneration %llu start_offset %llu dev_group %u\n"
	       "\t\tseek_speed %hhu bandwidth %hhu\n"
	       "\t\tuuid %s\n"
	       "\t\tfsid %s\n",
	       (unsigned long long)btrfs_device_id(eb, dev_item),
	       (unsigned long long)btrfs_device_total_bytes(eb, dev_item),
	       (unsigned long long)btrfs_device_bytes_used(eb, dev_item),
	       btrfs_device_io_align(eb, dev_item),
	       btrfs_device_io_width(eb, dev_item),
	       btrfs_device_sector_size(eb, dev_item),
	       (unsigned long long)btrfs_device_type(eb, dev_item),
	       (unsigned long long)btrfs_device_generation(eb, dev_item),
	       (unsigned long long)btrfs_device_start_offset(eb, dev_item),
	       btrfs_device_group(eb, dev_item),
	       btrfs_device_seek_speed(eb, dev_item),
	       btrfs_device_bandwidth(eb, dev_item),
	       uuid_str, fsid_str);
}

static void print_dir_item(struct extent_buffer *eb, u32 size,
			  struct btrfs_dir_item *di)
{
	u32 cur = 0;
	u32 len;
	u32 name_len;
	u32 data_len;
	char namebuf[BTRFS_NAME_LEN];
	struct btrfs_disk_key location;

	while (cur < size) {
		btrfs_dir_item_key(eb, di, &location);
		printf("\t\tlocation ");
		btrfs_print_key(&location);
		printf(" type ");
		print_dir_item_type(eb, di);
		printf("\n");
		name_len = btrfs_dir_name_len(eb, di);
		data_len = btrfs_dir_data_len(eb, di);
		len = (name_len <= sizeof(namebuf))? name_len: sizeof(namebuf);
		read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), len);
		printf("\t\ttransid %llu data_len %u name_len %u\n",
				btrfs_dir_transid(eb, di),
				data_len, name_len);
		printf("\t\tname: %.*s\n", len, namebuf);
		if (data_len) {
			len = (data_len <= sizeof(namebuf))? data_len: sizeof(namebuf);
			read_extent_buffer(eb, namebuf,
				(unsigned long)(di + 1) + name_len, len);
			printf("\t\tdata %.*s\n", len, namebuf);
		}
		len = sizeof(*di) + name_len + data_len;
		di = (struct btrfs_dir_item *)((char *)di + len);
		cur += len;
	}
}

static void print_root(struct extent_buffer *leaf, int slot)
{
	struct btrfs_root_item *ri;
	struct btrfs_root_item root_item;
	int len;
	char uuid_str[128];

	ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
	len = btrfs_item_size_nr(leaf, slot);

	memset(&root_item, 0, sizeof(root_item));
	read_extent_buffer(leaf, &root_item, (unsigned long)ri, len);

	printf("\t\troot data bytenr %llu level %d dirid %llu refs %u gen %llu\n",
		(unsigned long long)btrfs_root_bytenr(&root_item),
		btrfs_root_level(&root_item),
		(unsigned long long)btrfs_root_dirid(&root_item),
		btrfs_root_refs(&root_item),
		(unsigned long long)btrfs_root_generation(&root_item));

	if (root_item.generation == root_item.generation_v2) {
		uuid_unparse(root_item.uuid, uuid_str);
		printf("\t\tuuid %s\n", uuid_str);
		if (count_bytes(root_item.parent_uuid, BTRFS_UUID_SIZE, 0) != BTRFS_UUID_SIZE) {
			uuid_unparse(root_item.parent_uuid, uuid_str);
			printf("\t\tparent_uuid %s\n", uuid_str);
		}
		if (count_bytes(root_item.received_uuid, BTRFS_UUID_SIZE, 0) != BTRFS_UUID_SIZE) {
			uuid_unparse(root_item.received_uuid, uuid_str);
			printf("\t\treceived_uuid %s\n", uuid_str);
		}
		if (root_item.ctransid) {
			printf("\t\tctransid %llu otransid %llu stransid %llu rtransid %llu\n",
				btrfs_root_ctransid(&root_item),
				btrfs_root_otransid(&root_item),
				btrfs_root_stransid(&root_item),
				btrfs_root_rtransid(&root_item));
		}
	}
	if (btrfs_root_refs(&root_item) == 0) {
		struct btrfs_key drop_key;
		btrfs_disk_key_to_cpu(&drop_key,
				      &root_item.drop_progress);
		printf("\t\tdrop ");
		btrfs_print_key(&root_item.drop_progress);
		printf(" level %d\n", root_item.drop_level);
	}
}

static void print_dev_item(struct extent_buffer *eb,
			   struct btrfs_dev_item *dev_item)
{
	char disk_uuid_c[BTRFS_UUID_UNPARSED_SIZE];
	u8 disk_uuid[BTRFS_UUID_SIZE];

	read_extent_buffer(eb, disk_uuid,
			   (unsigned long)btrfs_device_uuid(dev_item),
			   BTRFS_UUID_SIZE);
	uuid_unparse(disk_uuid, disk_uuid_c);
	printf("\t\tdev item devid %llu "
	       "total_bytes %llu bytes used %Lu\n"
	       "\t\tdev uuid %s\n",
	       (unsigned long long)btrfs_device_id(eb, dev_item),
	       (unsigned long long)btrfs_device_total_bytes(eb, dev_item),
	       (unsigned long long)btrfs_device_bytes_used(eb, dev_item),
	       disk_uuid_c);
}

static void print_uuid_item(struct extent_buffer *l, unsigned long offset,
			    u32 item_size)
{
	if (!IS_ALIGNED(item_size, sizeof(u64))) {
		pr_warn("BTRFS: uuid item with illegal size %lu!\n",
			(unsigned long)item_size);
		return;
	}
	while (item_size) {
		__le64 subvol_id;

		read_extent_buffer(l, &subvol_id, offset, sizeof(subvol_id));
		printk(KERN_INFO "\t\tsubvol_id %llu\n",
		       (unsigned long long)le64_to_cpu(subvol_id));
		item_size -= sizeof(u64);
		offset += sizeof(u64);
	}
}

static void print_uuid_item(struct extent_buffer *l, unsigned long offset,
			    u32 item_size)
{
	if (item_size & (sizeof(u64) - 1)) {
		printf("btrfs: uuid item with illegal size %lu!\n",
		       (unsigned long)item_size);
		return;
	}
	while (item_size) {
		__le64 subvol_id;

		read_extent_buffer(l, &subvol_id, offset, sizeof(u64));
		printf("\t\tsubvol_id %llu\n",
			(unsigned long long)le64_to_cpu(subvol_id));
		item_size -= sizeof(u64);
		offset += sizeof(u64);
	}
}

/*
 * lookup the root with the highest offset for a given objectid.  The key we do
 * find is copied into 'key'.  If we find something return 0, otherwise 1, < 0
 * on error.
 */
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
			struct btrfs_root_item *item, struct btrfs_key *key)
{
	struct btrfs_path *path;
	struct btrfs_key search_key;
	struct btrfs_key found_key;
	struct extent_buffer *l;
	int ret;
	int slot;

	search_key.objectid = objectid;
	search_key.type = BTRFS_ROOT_ITEM_KEY;
	search_key.offset = (u64)-1;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
	if (ret < 0)
		goto out;

	BUG_ON(ret == 0);
	if (path->slots[0] == 0) {
		ret = 1;
		goto out;
	}
	l = path->nodes[0];
	slot = path->slots[0] - 1;
	btrfs_item_key_to_cpu(l, &found_key, slot);
	if (found_key.objectid != objectid ||
	    found_key.type != BTRFS_ROOT_ITEM_KEY) {
		ret = 1;
		goto out;
	}
	if (item)
		read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
				   sizeof(*item));
	if (key)
		memcpy(key, &found_key, sizeof(found_key));
	ret = 0;
out:
	btrfs_free_path(path);
	return ret;
}