Re: [PATCH] fix HDIO_GETGEO ioctl for linux

[Andres Salomon]

On Thu, 2005-11-17 at 13:03 +0100, Szakacsits Szabolcs wrote:
> On Wen, 16 Nov 2005, Andres Salomon wrote:
> 
> > I ran into a problem when running parted on Ubuntu Breezy with an sx8
> > device; it would SIGFPE upon startup.  The culprit, it turns out, is the
> > HDIO_GETGEO ioctl; 
> 
> This is very interesting. HDIO_GETGEO is completely useless for
> partitioning and it was supposed to be removed over a year ago.

It looks like hdparm still uses it, too.

> 
> If for some reason its wrong values end up to be used then that could
> explain why people are still corrupting their partition tables.


There's a comment in the code that suggests moving to EDD.  However, in
linux, that requires loading edd.ko (which is a module in debian
kernels, and is completely disabled in ubuntu kernels).  Anyone know of
another way to access EDD services?  Once edd.ko is actually loaded, we
end up w/ /sys/firmware/edd in 2.6.


> 
>       Szaka
> 
> > when asking for geometry information about a partition (the name-based
> > probing wasn't working well for devices like /dev/sx8/0p1, etc),
> > sectors and/or heads was 0.  This patch makes parted to not only check
> > if the ioctl didn't fail, but also make sure it returned sane results
> > (both are unsigned, so we don't have to worry about <0).
> > 
>