Calling statfs from python on OS X via ctypes for inspecting filesystem information

statfs.py

from ctypes import CDLL, Structure, c_uint32, c_int64, c_uint64, c_char, create_string_buffer, byref, c_ubyte, c_int16, c_int64, c_int32

# when _DARWIN_FEATURE_64_BIT_INODE is not defined
class statfs32(Structure):
    _fields_ = [
                ("f_otype",       c_int16),
                ("f_oflags",      c_int16),
                ("f_bsize",       c_int64),
                ("f_iosize",      c_int64),
                ("f_blocks",      c_int64),
                ("f_bfree",       c_int64),
                ("f_bavail",      c_int64),
                ("f_files",       c_int64),
                ("f_ffree",       c_int64),
                ("f_fsid",        c_uint64),
                ("f_owner",       c_uint32),
                ("f_reserved1",   c_int16),
                ("f_type",        c_int16),
                ("f_flags",       c_int64),
                ("f_reserved2",   c_int64*2),
                ("f_fstypename",  c_char*15),
                ("f_mntonname",   c_char*90),
                ("f_mntfromname", c_char*90),
                ("f_reserved3",   c_char),
                ("f_reserved4",   c_int64*4),
               ]

# when _DARWIN_FEATURE_64_BIT_INODE is defined
class statfs64(Structure):
    _fields_ = [
                ("f_bsize",       c_uint32),
                ("f_iosize",      c_int32),
                ("f_blocks",      c_uint64),
                ("f_bfree",       c_uint64),
                ("f_bavail",      c_uint64),
                ("f_files",       c_uint64),
                ("f_ffree",       c_uint64),
                ("f_fsid",        c_uint64),
                ("f_owner",       c_uint32),
                ("f_type",        c_uint32),
                ("f_flags",       c_uint32),
                ("f_fssubtype",   c_uint32),
                ("f_fstypename",  c_char*16),
                ("f_mntonname",   c_char*1024),
                ("f_mntfromname", c_char*1024),
                ("f_reserved",    c_uint32*8),
               ]

kern = CDLL('/usr/lib/system/libsystem_kernel.dylib')
fs_info = statfs32()
# put the path to any file on the mounted file system here
root_volume = create_string_buffer('/')
result = kern.statfs(root_volume, byref(fs_info))

# >>> fs_info.f_fstypename
# 'hfs'
# >>> fs_info.f_mntonname
# '/'
# >>> fs_info.f_mntfromname
# '/dev/disk1'
# >>> fs_info.f_type
# 17

Can you give more info when using statfs32 becomes unsafe? Or would it always work?