Re: [Qemu-devel] hd-geo-test failing on OpenIndiana

[Paolo Bonzini]

Il 28/01/2013 08:53, Markus Armbruster ha scritto:
> Andreas Färber <address@hidden> writes:
> 
>> Hello Markus,
>>
>> On OpenIndiana 151a7 I am seeing assertion failures for ret == 0 in
>> hd-geo-test.c:35:create_test_img(). It seems it is refusing to blow up
>> the temporary file. Any suggestion what to do about that?
> 
> Fine print on ftruncate():
> 
>     If fildes refers to a regular file, the ftruncate() function shall
>     cause the size of the file to be truncated to length.  If the size
>     of the file previously exceeded length, the extra data shall no
>     longer be available to reads on the file.  If the file previously
>     was smaller than this size, ftruncate() shall either increase the
>     size of the file or fail.  XSI-conformant systems shall increase the
>     size of the file.  If the file size is increased, the extended area
>     shall appear as if it were zero-filled. The value of the seek
>     pointer shall not be modified by a call to ftruncate().
> 
> Looks like OpenIndiana got stuck in the 20th century.
> 
> If you care for such losing systems, you need create_test_img to fall
> back or switch wholesale to a less elegant way to create the image.

Traditionally you used a 1-byte write to create a sparse file, preceeded
by an lseek to offset SIZE-1.

Paolo