bug#16409: Some amusing results with dd

[bugs]

On Fri, 10 Jan 2014, address@hidden wrote:

> dd has no idea what these suffixes are, apparently, regardless of what the 
> man page says.
>
>     dd if=/dev/zero of=ubuntunew.img bs=1E count=0 seek=1
>     dd: failed to truncate to 1152921504606846976 bytes in output file
>     ‘ubuntunew.img’: File too large
>     dd if=/dev/zero of=ubuntunew.img bs=1P count=0 seek=1
>     dd: failed to truncate to 1125899906842624 bytes in output file
>     ‘ubuntunew.img’: File too large
>
> dd apparently cannot actually create files with sizes that can't be fit in a 
> 64 bit number?
> I'm not sure if that's a dd limitation or this 3.11 kernel and ext4 
> filesystem.

JUST RTFS'd and dd is using off_t which I'm guessing based on the 16/15T thing below is totally not 
anything to do w/ dd.  0xFFFFFFFFFFF for some reason.
The unrecognised prefixes thing, and the memory exhaustion, might maybe 
possibly be interesting?