Function async_write

block/src/qcow_async.rs:605–621

(disk: &QcowDisk, offset: u64, data: &[u8])

    }

    fn async_write(disk: &QcowDisk, offset: u64, data: &[u8]) {
        let mut async_io = disk.create_async_io(1).unwrap();
        let iovec = libc::iovec {
            iov_base: data.as_ptr().cast::<libc::c_void>().cast_mut(),
            iov_len: data.len(),
        };
        async_io
            .write_vectored(offset as libc::off_t, &[iovec], 2)
            .unwrap();
        let (user_data, result) = wait_for_completion(async_io.as_mut());
        assert_eq!(user_data, 2);
        assert_eq!(
            result as usize,
            data.len(),
            "write should return requested length"
        );
    }

    fn async_read(disk: &QcowDisk, offset: u64, len: usize) -> Vec<u8> {
        let mut async_io = disk.create_async_io(1).unwrap();