Re: PROBLEM: ioctl (HDIO_GETGEO) on partition

[Mark Lord <lkml@rtr.ca>]

Mark Lord wrote:
> Sarangi_Santosh@emc.com wrote:
..
>>   if ((sts = ioctl(fd, HDIO_GETGEO, &hd_geometry_rec)) < 0) ------->
>> ioctl((HDIO_GETGEO)  is failing for device partition (/dev/emcpowerg1)
>>     {
>>       close(fd);
>>       return OS_SYSTEM_CALL_FAILED;
>>     }
..

And while we're at it, that code above REALLY wants
a perror(p_ppdevname) call just before the close(fd) line.
That way, when it fails, you'll find out *why* it fails,
making bugs like this much easier to figure out.

.. 
> The code should try HDIO_GETGEO_BIG before falling back to HDIO_GETGEO.
> But neither will work for LARGE drives (>= 2TB) on 32-bit systems,
> so the code really should try sysfs for this info before using the ioctls.
> 
> Sample code to do this correctly is in the geom.c file of recent hdparm
> source code packages from sourceforge.