From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: What to do about the 2TB limit on HDIO_GETGEO ?
Date: Mon, 24 Mar 2008 22:13:55 -0700
Message-ID: <47E88A13.70808@zytor.com>
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To: Mark Lord <lkml@rtr.ca>
Cc: Jens Axboe <axboe@kernel.dk>, Jeff Garzik <jgarzik@pobox.com>, Tejun Heo <htejun@gmail.com>, Greg KH <gregkh@suse.de>, Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@linux-foundation.org>, Linux Kernel <linux-kernel@vger.kernel.org>, IDE/ATA development list <linux-ide@vger.kernel.org>, linux-scsi <linux-scsi@vger.kernel.org>
List-Id: linux-ide@vger.kernel.org

Mark Lord wrote:
> 
> One candidate might seem to be the existing /sys/block/dev/partition/start
> which I expect is already 64-bit friendly.
> 
> But this requires about 150 lines of somewhat complex C code to access,
> using only the dev_t (from stat(2) on a file) as a starting point,
> or less if one relies upon the udev device name matching the sysfs 
> device name.
> 
> Is it time now for HDIO_GETGEO64 to make an appearance?
> Similar to how the existing BLKGETSIZE64 is supplanting BLKGETSIZE ?
> 

Probably a better thing to have would be a way to look up block devices 
in sysfs by device number.

	-hpa