Function posix_fallocate 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn posix_fallocate(
    fd: c_int,
    offset: off_t,
    len: off_t,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/posix_fallocate.html.

Ensures that any required storage for regular file data starting at offset and continuing for len bytes is allocated on the file system storage media.

Upon success, returns 0. Upon failure, returns error number.