Function btrfsutil_sys::btrfs_util_get_default_subvolume_fd

pub unsafe extern "C" fn btrfs_util_get_default_subvolume_fd(
    fd: c_int, 
    id_ret: *mut u64
) -> btrfs_util_error

btrfs_util_get_default_subvolume_fd() - See btrfs_util_get_default_subvolume().