Re: ioengine=sync issue on Windows

[Bruce Cran <bruce@cran.org.uk>]

On 4/1/2014 9:11 PM, Bruce Cran wrote:
>
> On 3/12/2014 10:33 AM, Jens Axboe wrote:
>> On 03/12/2014 09:41 AM, Sébastien Bouchex Bellomié wrote:
>>>
>>> fio: pid=5144, err=5/file:backend.c:768, func=full resid, 
>>> error=Input/output error
>>>
>>> random_read: (groupid=0, jobs=1): err= 5 (file:backend.c:768, 
>>> func=full resid, error=Input/output error): pid=5144: Wed Mar 12 
>>> 16:36:45 2014
>> Bruce, do you know why that is?
>>
>
> It appears to be because after seeking, there's 92 bytes before a 
> space in the file (i.e. it's a sparse file), and instead of filling 
> the buffer with 0's read() is for some reason returning 0.
>

I was wrong.  The problem has something to do with fil_io_buffer - and 
in particular __fill_random_buf. The io error disappears if I change the 
line:

*ptr = seed;
to
*ptr = 1;

Also, fio-2.0.15 works, while fio-2.1 doesn't.

-- 
Bruce