fstatfs64 is expected to disappear from a future version of the LSB; applications should call the fstatvfs64 interface.
fstatfs64 returns information about a mounted file system. fd is the open file descriptor of any file within the mounted filesystem.
fstatfs64 is the 64-bit version of fstatfs.
On success, 0 is returned. On error, -1 is returned and the global variable errno is set appropriately.