Re: [PATCH 2.6.20] libata: Support HDIO_DRIVE_TASKFILE ioctl

[Tejun Heo <htejun@gmail.com>]

Hello,

Anand Kulkarni wrote:
> Hi,
> 
> Attached is a patch to allow HDIO_DRIVE_TASKFILE ioctl calls to libata
> devices so that arbitrary ATA commands that need PIO data transfers in
> either direction can be issued. I have tested it with linux kernel
> 2.6.20. The format of the input arguments is the same as for the
> regular ATA HDIO_DRIVE_TASKFILE ioctl : Code that makes ioctl calls to
> ATA devices on /dev/hda can be sent as is to SATA devices on /dev/sda.
> 
> Since this is the first time I am sending a patch, please let me know
> if I should do anything differently.

I was kind of hoping we could drop HDIO_DRIVE_TASKFILE.  Please take a
look at the HDIO_DRIVE_TASKFILE section of Documentation/ioctl/hdio.txt.
 That's one scary scary ioctl and we still haven't sorted out which are
features and which are bugs.

For backward compatibility HDIO_DRIVE_CMD and HDIO_DRIVE_TASK are
implemented and most applications seem to be happy with it.  If you need
real fine control over command execution, the recommended way is to use
SAT via SG_IO.

-- 
tejun