Example #1
0
PUBLIC void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_iterator *iter)
{
	if (iter) {
		free(iter->cur_path);
		free(iter->search_stack);
		if (iter->cur_fd != iter->fd)
			SAVE_ERRNO_AND_CLOSE(iter->cur_fd);
		if (iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD)
			SAVE_ERRNO_AND_CLOSE(iter->fd);
		free(iter);
	}
}
Example #2
0
static enum btrfs_util_error delete_subvolume_children(int parent_fd,
						       const char *name)
{
	struct btrfs_util_subvolume_iterator *iter;
	enum btrfs_util_error err;
	int fd;

	fd = openat(parent_fd, name, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_create_subvolume_iterator_fd(fd, 0,
						      BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER,
						      &iter);
	if (err)
		goto out;

	for (;;) {
		char child_name[BTRFS_PATH_NAME_MAX + 1];
		char *child_path;
		int child_parent_fd;

		err = btrfs_util_subvolume_iterator_next(iter, &child_path,
							 NULL);
		if (err) {
			if (err == BTRFS_UTIL_ERROR_STOP_ITERATION)
				err = BTRFS_UTIL_OK;
			break;
		}

		err = openat_parent_and_name(fd, child_path, child_name,
					     sizeof(child_name),
					     &child_parent_fd);
		free(child_path);
		if (err)
			break;

		err = btrfs_util_delete_subvolume_fd(child_parent_fd,
						     child_name, 0);
		SAVE_ERRNO_AND_CLOSE(child_parent_fd);
		if (err)
			break;
	}

	btrfs_util_destroy_subvolume_iterator(iter);
out:
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}
Example #3
0
static enum btrfs_util_error pop_search_stack(struct btrfs_util_subvolume_iterator *iter)
{
	struct search_stack_entry *top, *parent;
	int fd, parent_fd;
	size_t i;

	if (iter->use_tree_search || iter->search_stack_len == 1) {
		iter->search_stack_len--;
		return BTRFS_UTIL_OK;
	}

	top = top_search_stack_entry(iter);
	iter->search_stack_len--;
	parent = top_search_stack_entry(iter);

	fd = iter->cur_fd;
	for (i = parent->path_len; i < top->path_len; i++) {
		if (i == 0 || iter->cur_path[i] == '/') {
			parent_fd = openat(fd, "..", O_RDONLY);
			if (fd != iter->cur_fd)
				SAVE_ERRNO_AND_CLOSE(fd);
			if (parent_fd == -1)
				return BTRFS_UTIL_ERROR_OPEN_FAILED;
			fd = parent_fd;
		}
	}
	if (iter->cur_fd != iter->fd)
		close(iter->cur_fd);
	iter->cur_fd = fd;

	return BTRFS_UTIL_OK;
}
Example #4
0
PUBLIC enum btrfs_util_error btrfs_util_subvolume_id(const char *path,
						     uint64_t *id_ret)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_subvolume_id_fd(fd, id_ret);
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}
Example #5
0
PUBLIC enum btrfs_util_error btrfs_util_set_subvolume_read_only(const char *path,
								bool read_only)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_set_subvolume_read_only_fd(fd, read_only);
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}
Example #6
0
PUBLIC enum btrfs_util_error btrfs_util_delete_subvolume(const char *path,
							 int flags)
{
	char name[BTRFS_PATH_NAME_MAX + 1];
	enum btrfs_util_error err;
	int parent_fd;

	err = openat_parent_and_name(AT_FDCWD, path, name, sizeof(name),
				     &parent_fd);
	if (err)
		return err;

	err = btrfs_util_delete_subvolume_fd(parent_fd, name, flags);
	SAVE_ERRNO_AND_CLOSE(parent_fd);
	return err;
}
Example #7
0
PUBLIC enum btrfs_util_error btrfs_util_create_snapshot(const char *source,
							const char *path,
							int flags,
							uint64_t *async_transid,
							struct btrfs_util_qgroup_inherit *qgroup_inherit)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(source, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_create_snapshot_fd(fd, path, flags, async_transid,
					    qgroup_inherit);
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}
Example #8
0
PUBLIC enum btrfs_util_error btrfs_util_create_subvolume(const char *path,
							 int flags,
							 uint64_t *async_transid,
							 struct btrfs_util_qgroup_inherit *qgroup_inherit)
{
	char name[BTRFS_SUBVOL_NAME_MAX + 1];
	enum btrfs_util_error err;
	int parent_fd;

	err = openat_parent_and_name(AT_FDCWD, path, name, sizeof(name),
				     &parent_fd);
	if (err)
		return err;

	err = btrfs_util_create_subvolume_fd(parent_fd, name, flags,
					    async_transid, qgroup_inherit);
	SAVE_ERRNO_AND_CLOSE(parent_fd);
	return err;
}
Example #9
0
PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_iterator(const char *path,
								  uint64_t top,
								  int flags,
								  struct btrfs_util_subvolume_iterator **ret)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_create_subvolume_iterator_fd(fd, top, flags, ret);
	if (err)
		SAVE_ERRNO_AND_CLOSE(fd);
	else
		(*ret)->flags |= BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD;

	return err;
}
Example #10
0
static enum btrfs_util_error snapshot_subvolume_children(int fd, int parent_fd,
							 const char *name,
							 uint64_t *async_transid)
{
	struct btrfs_util_subvolume_iterator *iter;
	enum btrfs_util_error err;
	int dstfd;

	dstfd = openat(parent_fd, name, O_RDONLY);
	if (dstfd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_create_subvolume_iterator_fd(fd, 0, 0, &iter);
	if (err)
		goto out;

	for (;;) {
		char child_name[BTRFS_SUBVOL_NAME_MAX + 1];
		char *child_path;
		int child_fd, new_parent_fd;
		uint64_t tmp_transid;

		err = btrfs_util_subvolume_iterator_next(iter, &child_path,
							 NULL);
		if (err) {
			if (err == BTRFS_UTIL_ERROR_STOP_ITERATION)
				err = BTRFS_UTIL_OK;
			break;
		}

		/* Remove the placeholder directory. */
		if (unlinkat(dstfd, child_path, AT_REMOVEDIR) == -1) {
			free(child_path);
			err = BTRFS_UTIL_ERROR_RMDIR_FAILED;
			break;
		}

		child_fd = openat(fd, child_path, O_RDONLY);
		if (child_fd == -1) {
			free(child_path);
			err = BTRFS_UTIL_ERROR_OPEN_FAILED;
			break;
		}

		err = openat_parent_and_name(dstfd, child_path, child_name,
					     sizeof(child_name),
					     &new_parent_fd);
		free(child_path);
		if (err) {
			SAVE_ERRNO_AND_CLOSE(child_fd);
			break;
		}

		err = btrfs_util_create_snapshot_fd2(child_fd, new_parent_fd,
						     child_name, 0,
						     async_transid ? &tmp_transid : NULL,
						     NULL);
		SAVE_ERRNO_AND_CLOSE(child_fd);
		SAVE_ERRNO_AND_CLOSE(new_parent_fd);
		if (err)
			break;
		if (async_transid && tmp_transid > *async_transid)
			*async_transid = tmp_transid;
	}

	btrfs_util_destroy_subvolume_iterator(iter);
out:
	SAVE_ERRNO_AND_CLOSE(dstfd);
	return err;
}
Example #11
0
static enum btrfs_util_error build_subvol_path(struct btrfs_util_subvolume_iterator *iter,
					       const struct btrfs_ioctl_search_header *header,
					       const struct btrfs_root_ref *ref,
					       const char *name,
					       size_t *path_len_ret)
{
	struct btrfs_ioctl_ino_lookup_args lookup = {
		.treeid = header->objectid,
		.objectid = le64_to_cpu(ref->dirid),
	};
	struct search_stack_entry *top = top_search_stack_entry(iter);
	size_t dir_len, name_len, path_len;
	char *p;
	int ret;

	ret = ioctl(iter->fd, BTRFS_IOC_INO_LOOKUP, &lookup);
	if (ret == -1)
		return BTRFS_UTIL_ERROR_INO_LOOKUP_FAILED;

	dir_len = strlen(lookup.name);
	name_len = le16_to_cpu(ref->name_len);

	path_len = top->path_len;
	/*
	 * We need a joining slash if we have a current path and a subdirectory.
	 */
	if (top->path_len && dir_len)
		path_len++;
	path_len += dir_len;
	/*
	 * We need another joining slash if we have a current path and a name,
	 * but not if we have a subdirectory, because the lookup ioctl includes
	 * a trailing slash.
	 */
	if (top->path_len && !dir_len && name_len)
		path_len++;
	path_len += name_len;

	if (path_len > iter->cur_path_capacity) {
		char *tmp = realloc(iter->cur_path, path_len);

		if (!tmp)
			return BTRFS_UTIL_ERROR_NO_MEMORY;
		iter->cur_path = tmp;
		iter->cur_path_capacity = path_len;
	}

	p = iter->cur_path + top->path_len;
	if (top->path_len && dir_len)
		*p++ = '/';
	memcpy(p, lookup.name, dir_len);
	p += dir_len;
	if (top->path_len && !dir_len && name_len)
		*p++ = '/';
	memcpy(p, name, name_len);
	p += name_len;

	*path_len_ret = path_len;

	return BTRFS_UTIL_OK;
}

PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter,
								char **path_ret,
								uint64_t *id_ret)
{
	struct search_stack_entry *top;
	const struct btrfs_ioctl_search_header *header;
	const struct btrfs_root_ref *ref;
	const char *name;
	enum btrfs_util_error err;
	size_t path_len;
	int ret;

	for (;;) {
		for (;;) {
			if (iter->search_stack_len == 0)
				return BTRFS_UTIL_ERROR_STOP_ITERATION;

			top = top_search_stack_entry(iter);
			if (top->items_pos < top->search.key.nr_items) {
				break;
			} else {
				top->search.key.nr_items = 4096;
				ret = ioctl(iter->fd, BTRFS_IOC_TREE_SEARCH, &top->search);
				if (ret == -1)
					return BTRFS_UTIL_ERROR_SEARCH_FAILED;
				top->items_pos = 0;
				top->buf_off = 0;

				if (top->search.key.nr_items == 0) {
					iter->search_stack_len--;
					if ((iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER) &&
					    iter->search_stack_len)
						goto out;
				}
			}
		}

		header = (struct btrfs_ioctl_search_header *)(top->search.buf + top->buf_off);

		top->items_pos++;
		top->buf_off += sizeof(*header) + header->len;
		top->search.key.min_offset = header->offset + 1;

		/* This shouldn't happen, but handle it just in case. */
		if (header->type != BTRFS_ROOT_REF_KEY)
			continue;

		ref = (struct btrfs_root_ref *)(header + 1);
		name = (const char *)(ref + 1);
		err = build_subvol_path(iter, header, ref, name, &path_len);
		if (err)
			return err;

		err = append_to_search_stack(iter, header->offset, path_len);
		if (err)
			return err;

		if (!(iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER)) {
			top = top_search_stack_entry(iter);
			goto out;
		}
	}

out:
	if (path_ret) {
		*path_ret = malloc(top->path_len + 1);
		if (!*path_ret)
			return BTRFS_UTIL_ERROR_NO_MEMORY;
		memcpy(*path_ret, iter->cur_path, top->path_len);
		(*path_ret)[top->path_len] = '\0';
	}
	if (id_ret)
		*id_ret = top->search.key.min_objectid;
	return BTRFS_UTIL_OK;
}

PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrfs_util_subvolume_iterator *iter,
								     char **path_ret,
								     struct btrfs_util_subvolume_info *subvol)
{
	enum btrfs_util_error err;
	uint64_t id;

	err = btrfs_util_subvolume_iterator_next(iter, path_ret, &id);
	if (err)
		return err;

	return btrfs_util_subvolume_info_fd(iter->fd, id, subvol);
}

PUBLIC enum btrfs_util_error btrfs_util_deleted_subvolumes(const char *path,
							   uint64_t **ids,
							   size_t *n)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_deleted_subvolumes_fd(fd, ids, n);
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}

PUBLIC enum btrfs_util_error btrfs_util_deleted_subvolumes_fd(int fd,
							      uint64_t **ids,
							      size_t *n)
{
	size_t capacity = 0;
	struct btrfs_ioctl_search_args search = {
		.key = {
			.tree_id = BTRFS_ROOT_TREE_OBJECTID,
			.min_objectid = BTRFS_ORPHAN_OBJECTID,
			.max_objectid = BTRFS_ORPHAN_OBJECTID,
			.min_type = BTRFS_ORPHAN_ITEM_KEY,
			.max_type = BTRFS_ORPHAN_ITEM_KEY,
			.min_offset = 0,
			.max_offset = UINT64_MAX,
			.min_transid = 0,
			.max_transid = UINT64_MAX,
			.nr_items = 0,
		},
	};
	enum btrfs_util_error err;
	size_t items_pos = 0, buf_off = 0;
	int ret;

	*ids = NULL;
	*n = 0;
	for (;;) {
		const struct btrfs_ioctl_search_header *header;

		if (items_pos >= search.key.nr_items) {
			search.key.nr_items = 4096;
			ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search);
			if (ret == -1) {
				err = BTRFS_UTIL_ERROR_SEARCH_FAILED;
				goto out;
			}
			items_pos = 0;
			buf_off = 0;

			if (search.key.nr_items == 0)
				break;
		}

		header = (struct btrfs_ioctl_search_header *)(search.buf + buf_off);

		/*
		 * The orphan item might be for a free space cache inode, so
		 * check if there's a matching root item.
		 */
		err = btrfs_util_subvolume_info_fd(fd, header->offset, NULL);
		if (!err) {
			if (*n >= capacity) {
				size_t new_capacity;
				uint64_t *new_ids;

				new_capacity = capacity ? capacity * 2 : 1;
				new_ids = reallocarray(*ids, new_capacity,
						       sizeof(**ids));
				if (!new_ids) {
					err = BTRFS_UTIL_ERROR_NO_MEMORY;
					goto out;
				}

				*ids = new_ids;
				capacity = new_capacity;
			}
			(*ids)[(*n)++] = header->offset;
		} else if (err != BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND) {
			goto out;
		}

		items_pos++;
		buf_off += sizeof(*header) + header->len;
		search.key.min_offset = header->offset + 1;
	}

	err = BTRFS_UTIL_OK;
out:
	if (err) {
		free(*ids);
		*ids = NULL;
		*n = 0;
	}
	return err;
}
Example #12
0
PUBLIC enum btrfs_util_error btrfs_util_subvolume_id_fd(int fd,
							uint64_t *id_ret)
{
	struct btrfs_ioctl_ino_lookup_args args = {
		.treeid = 0,
		.objectid = BTRFS_FIRST_FREE_OBJECTID,
	};
	int ret;

	ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
	if (ret == -1) {
		close(fd);
		return BTRFS_UTIL_ERROR_INO_LOOKUP_FAILED;
	}

	*id_ret = args.treeid;

	return BTRFS_UTIL_OK;
}

PUBLIC enum btrfs_util_error btrfs_util_subvolume_path(const char *path,
						       uint64_t id,
						       char **path_ret)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_subvolume_path_fd(fd, id, path_ret);
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}

PUBLIC enum btrfs_util_error btrfs_util_subvolume_path_fd(int fd, uint64_t id,
							  char **path_ret)
{
	char *path, *p;
	size_t capacity = 4096;

	if (id == 0) {
		enum btrfs_util_error err;

		err = btrfs_util_is_subvolume_fd(fd);
		if (err)
			return err;

		err = btrfs_util_subvolume_id_fd(fd, &id);
		if (err)
			return err;
	}

	path = malloc(capacity);
	if (!path)
		return BTRFS_UTIL_ERROR_NO_MEMORY;
	p = path + capacity - 1;
	p[0] = '\0';

	while (id != BTRFS_FS_TREE_OBJECTID) {
		struct btrfs_ioctl_search_args search = {
			.key = {
				.tree_id = BTRFS_ROOT_TREE_OBJECTID,
				.min_objectid = id,
				.max_objectid = id,
				.min_type = BTRFS_ROOT_BACKREF_KEY,
				.max_type = BTRFS_ROOT_BACKREF_KEY,
				.min_offset = 0,
				.max_offset = UINT64_MAX,
				.min_transid = 0,
				.max_transid = UINT64_MAX,
				.nr_items = 1,
			},
		};
		struct btrfs_ioctl_ino_lookup_args lookup;
		const struct btrfs_ioctl_search_header *header;
		const struct btrfs_root_ref *ref;
		const char *name;
		uint16_t name_len;
		size_t lookup_len;
		size_t total_len;
		int ret;

		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search);
		if (ret == -1) {
			free(path);
			return BTRFS_UTIL_ERROR_SEARCH_FAILED;
		}

		if (search.key.nr_items == 0) {
			free(path);
			errno = ENOENT;
			return BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND;
		}

		header = (struct btrfs_ioctl_search_header *)search.buf;
		ref = (struct btrfs_root_ref *)(header + 1);
		name = (char *)(ref + 1);
		name_len = le16_to_cpu(ref->name_len);

		id = header->offset;

		lookup.treeid = id;
		lookup.objectid = le64_to_cpu(ref->dirid);
		ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &lookup);
		if (ret == -1) {
			free(path);
			return BTRFS_UTIL_ERROR_SEARCH_FAILED;
		}
		lookup_len = strlen(lookup.name);

		total_len = name_len + lookup_len + (id != BTRFS_FS_TREE_OBJECTID);
		if (p - total_len < path) {
			char *new_path, *new_p;
			size_t new_capacity = capacity * 2;

			new_path = malloc(new_capacity);
			if (!new_path) {
				free(path);
				return BTRFS_UTIL_ERROR_NO_MEMORY;
			}
			new_p = new_path + new_capacity - (path + capacity - p);
			memcpy(new_p, p, path + capacity - p);
			free(path);
			path = new_path;
			p = new_p;
			capacity = new_capacity;
		}
		p -= name_len;
		memcpy(p, name, name_len);
		p -= lookup_len;
		memcpy(p, lookup.name, lookup_len);
		if (id != BTRFS_FS_TREE_OBJECTID)
			*--p = '/';
	}

	if (p != path)
		memmove(path, p, path + capacity - p);

	*path_ret = path;

	return BTRFS_UTIL_OK;
}
Example #13
0
static enum btrfs_util_error build_subvol_path_privileged(struct btrfs_util_subvolume_iterator *iter,
							  const struct btrfs_ioctl_search_header *header,
							  const struct btrfs_root_ref *ref,
							  const char *name,
							  size_t *path_len_ret)
{
	struct btrfs_ioctl_ino_lookup_args lookup = {
		.treeid = header->objectid,
		.objectid = le64_to_cpu(ref->dirid),
	};
	int ret;

	ret = ioctl(iter->fd, BTRFS_IOC_INO_LOOKUP, &lookup);
	if (ret == -1)
		return BTRFS_UTIL_ERROR_INO_LOOKUP_FAILED;

	return build_subvol_path(iter, name, le16_to_cpu(ref->name_len),
				 lookup.name, strlen(lookup.name),
				 path_len_ret);
}

static enum btrfs_util_error build_subvol_path_unprivileged(struct btrfs_util_subvolume_iterator *iter,
							    uint64_t treeid,
							    uint64_t dirid,
							    size_t *path_len_ret)
{
	struct btrfs_ioctl_ino_lookup_user_args args = {
		.treeid = treeid,
		.dirid = dirid,
	};
	int ret;

	ret = ioctl(iter->cur_fd, BTRFS_IOC_INO_LOOKUP_USER, &args);
	if (ret == -1)
		return BTRFS_UTIL_ERROR_INO_LOOKUP_USER_FAILED;

	return build_subvol_path(iter, args.name, strlen(args.name),
				 args.path, strlen(args.path), path_len_ret);
}

static enum btrfs_util_error subvolume_iterator_next_tree_search(struct btrfs_util_subvolume_iterator *iter,
								 char **path_ret,
								 uint64_t *id_ret)
{
	struct search_stack_entry *top;
	const struct btrfs_ioctl_search_header *header;
	const struct btrfs_root_ref *ref;
	const char *name;
	enum btrfs_util_error err;
	size_t path_len;
	int ret;

	for (;;) {
		for (;;) {
			if (iter->search_stack_len == 0)
				return BTRFS_UTIL_ERROR_STOP_ITERATION;

			top = top_search_stack_entry(iter);
			if (top->items_pos < top->search.key.nr_items) {
				break;
			} else {
				top->search.key.nr_items = 4096;
				ret = ioctl(iter->fd, BTRFS_IOC_TREE_SEARCH, &top->search);
				if (ret == -1)
					return BTRFS_UTIL_ERROR_SEARCH_FAILED;
				top->items_pos = 0;
				top->buf_off = 0;

				if (top->search.key.nr_items == 0) {
					/*
					 * This never fails for use_tree_search.
					 */
					pop_search_stack(iter);
					if ((iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER) &&
					    iter->search_stack_len)
						goto out;
				}
			}
		}

		header = (struct btrfs_ioctl_search_header *)(top->search.buf + top->buf_off);

		top->items_pos++;
		top->buf_off += sizeof(*header) + header->len;
		top->search.key.min_offset = header->offset + 1;

		/* This shouldn't happen, but handle it just in case. */
		if (header->type != BTRFS_ROOT_REF_KEY)
			continue;

		ref = (struct btrfs_root_ref *)(header + 1);
		name = (const char *)(ref + 1);
		err = build_subvol_path_privileged(iter, header, ref, name,
						   &path_len);
		if (err)
			return err;

		err = append_to_search_stack(iter, header->offset, path_len);
		if (err)
			return err;

		if (!(iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER)) {
			top = top_search_stack_entry(iter);
			goto out;
		}
	}

out:
	if (path_ret) {
		*path_ret = malloc(top->path_len + 1);
		if (!*path_ret)
			return BTRFS_UTIL_ERROR_NO_MEMORY;
		memcpy(*path_ret, iter->cur_path, top->path_len);
		(*path_ret)[top->path_len] = '\0';
	}
	if (id_ret)
		*id_ret = top->search.key.min_objectid;
	return BTRFS_UTIL_OK;
}

static enum btrfs_util_error subvolume_iterator_next_unprivileged(struct btrfs_util_subvolume_iterator *iter,
								  char **path_ret,
								  uint64_t *id_ret)
{
	struct search_stack_entry *top;
	uint64_t treeid, dirid;
	enum btrfs_util_error err;
	size_t path_len;
	int ret;

	for (;;) {
		for (;;) {
			if (iter->search_stack_len == 0)
				return BTRFS_UTIL_ERROR_STOP_ITERATION;

			top = top_search_stack_entry(iter);
			if (top->items_pos < top->rootref_args.num_items) {
				break;
			} else {
				ret = ioctl(iter->cur_fd,
					    BTRFS_IOC_GET_SUBVOL_ROOTREF,
					    &top->rootref_args);
				if (ret == -1 && errno != EOVERFLOW)
					return BTRFS_UTIL_ERROR_GET_SUBVOL_ROOTREF_FAILED;
				top->items_pos = 0;

				if (top->rootref_args.num_items == 0) {
					err = pop_search_stack(iter);
					if (err)
						return err;
					if ((iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER) &&
					    iter->search_stack_len)
						goto out;
				}
			}
		}

		treeid = top->rootref_args.rootref[top->items_pos].treeid;
		dirid = top->rootref_args.rootref[top->items_pos].dirid;
		top->items_pos++;
		err = build_subvol_path_unprivileged(iter, treeid, dirid,
						     &path_len);
		if (err) {
			/* Skip the subvolume if we can't access it. */
			if (errno == EACCES)
				continue;
			return err;
		}

		err = append_to_search_stack(iter, treeid, path_len);
		if (err) {
			/*
			 * Skip the subvolume if it does not exist (which can
			 * happen if there is another filesystem mounted over a
			 * parent directory) or we don't have permission to
			 * access it.
			 */
			if (errno == ENOENT || errno == EACCES)
				continue;
			return err;
		}

		if (!(iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER)) {
			top = top_search_stack_entry(iter);
			goto out;
		}
	}

out:
	if (path_ret) {
		*path_ret = malloc(top->path_len + 1);
		if (!*path_ret)
			return BTRFS_UTIL_ERROR_NO_MEMORY;
		memcpy(*path_ret, iter->cur_path, top->path_len);
		(*path_ret)[top->path_len] = '\0';
	}
	if (id_ret)
		*id_ret = top->id;
	return BTRFS_UTIL_OK;
}

PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter,
								char **path_ret,
								uint64_t *id_ret)
{
	if (iter->use_tree_search) {
		return subvolume_iterator_next_tree_search(iter, path_ret,
							   id_ret);
	} else {
		return subvolume_iterator_next_unprivileged(iter, path_ret,
							    id_ret);
	}
}

PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrfs_util_subvolume_iterator *iter,
								     char **path_ret,
								     struct btrfs_util_subvolume_info *subvol)
{
	enum btrfs_util_error err;
	uint64_t id;

	err = btrfs_util_subvolume_iterator_next(iter, path_ret, &id);
	if (err)
		return err;

	if (iter->use_tree_search)
		return btrfs_util_subvolume_info_fd(iter->fd, id, subvol);
	else
		return btrfs_util_subvolume_info_fd(iter->cur_fd, 0, subvol);
}

PUBLIC enum btrfs_util_error btrfs_util_deleted_subvolumes(const char *path,
							   uint64_t **ids,
							   size_t *n)
{
	enum btrfs_util_error err;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd == -1)
		return BTRFS_UTIL_ERROR_OPEN_FAILED;

	err = btrfs_util_deleted_subvolumes_fd(fd, ids, n);
	SAVE_ERRNO_AND_CLOSE(fd);
	return err;
}

PUBLIC enum btrfs_util_error btrfs_util_deleted_subvolumes_fd(int fd,
							      uint64_t **ids,
							      size_t *n)
{
	size_t capacity = 0;
	struct btrfs_ioctl_search_args search = {
		.key = {
			.tree_id = BTRFS_ROOT_TREE_OBJECTID,
			.min_objectid = BTRFS_ORPHAN_OBJECTID,
			.max_objectid = BTRFS_ORPHAN_OBJECTID,
			.min_type = BTRFS_ORPHAN_ITEM_KEY,
			.max_type = BTRFS_ORPHAN_ITEM_KEY,
			.min_offset = 0,
			.max_offset = UINT64_MAX,
			.min_transid = 0,
			.max_transid = UINT64_MAX,
			.nr_items = 0,
		},
	};
	enum btrfs_util_error err;
	size_t items_pos = 0, buf_off = 0;
	int ret;

	*ids = NULL;
	*n = 0;
	for (;;) {
		const struct btrfs_ioctl_search_header *header;

		if (items_pos >= search.key.nr_items) {
			search.key.nr_items = 4096;
			ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search);
			if (ret == -1) {
				err = BTRFS_UTIL_ERROR_SEARCH_FAILED;
				goto out;
			}
			items_pos = 0;
			buf_off = 0;

			if (search.key.nr_items == 0)
				break;
		}

		header = (struct btrfs_ioctl_search_header *)(search.buf + buf_off);

		/*
		 * The orphan item might be for a free space cache inode, so
		 * check if there's a matching root item.
		 */
		err = btrfs_util_subvolume_info_fd(fd, header->offset, NULL);
		if (!err) {
			if (*n >= capacity) {
				size_t new_capacity;
				uint64_t *new_ids;

				new_capacity = capacity ? capacity * 2 : 1;
				new_ids = reallocarray(*ids, new_capacity,
						       sizeof(**ids));
				if (!new_ids) {
					err = BTRFS_UTIL_ERROR_NO_MEMORY;
					goto out;
				}

				*ids = new_ids;
				capacity = new_capacity;
			}
			(*ids)[(*n)++] = header->offset;
		} else if (err != BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND) {
			goto out;
		}

		items_pos++;
		buf_off += sizeof(*header) + header->len;
		search.key.min_offset = header->offset + 1;
	}

	err = BTRFS_UTIL_OK;
out:
	if (err) {
		free(*ids);
		*ids = NULL;
		*n = 0;
	}
	return err;
}