-static int get_btrfs_block_device(const char *path, dev_t *dev) {
- struct btrfs_ioctl_fs_info_args fsi = {};
- _cleanup_close_ int fd = -1;
- uint64_t id;
-
- assert(path);
- assert(dev);
-
- fd = open(path, O_DIRECTORY|O_CLOEXEC);
- if (fd < 0)
- return -errno;
-
- if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0)
- return -errno;
-
- /* We won't do this for btrfs RAID */
- if (fsi.num_devices != 1)
- return 0;
-
- for (id = 1; id <= fsi.max_id; id++) {
- struct btrfs_ioctl_dev_info_args di = {
- .devid = id,
- };
- struct stat st;
-
- if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) {
- if (errno == ENODEV)
- continue;
-
- return -errno;
- }
-
- if (stat((char*) di.path, &st) < 0)
- return -errno;
-
- if (!S_ISBLK(st.st_mode))
- return -ENODEV;
-
- if (major(st.st_rdev) == 0)
- return -ENODEV;
-
- *dev = st.st_rdev;
- return 1;
- }
-
- return -ENODEV;
-}
-