From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751386AbWFIDnl (ORCPT ); Thu, 8 Jun 2006 23:43:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751385AbWFIDnl (ORCPT ); Thu, 8 Jun 2006 23:43:41 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:55524 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1751378AbWFIDnk (ORCPT ); Thu, 8 Jun 2006 23:43:40 -0400 Message-ID: <4488EE68.9000605@garzik.org> Date: Thu, 08 Jun 2006 23:43:36 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.2 (X11/20060501) MIME-Version: 1.0 To: linux-ide@vger.kernel.org CC: "zhao, forrest" , htejun@gmail.com, randy_dunlap , Alan Cox , Linux Kernel Subject: [RFC] ATA host-protected area (HPA) device mapper? References: <1149751860.29552.79.camel@forrest26.sh.intel.com> <44883BAE.7070406@pobox.com> <1149820043.5721.7.camel@forrest26.sh.intel.com> <4488E6F6.10306@pobox.com> In-Reply-To: <4488E6F6.10306@pobox.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.2 (----) X-Spam-Report: SpamAssassin version 3.1.1 on srv5.dvmed.net summary: Content analysis details: (-4.2 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org As I just mentioned on linux-ide in another email: libata should -- like drivers/ide -- call the ATA "set max" command to fully address the hard drive, including the special "host-protected area" (HPA). We should do this because the Linux standard is to export the raw hardware directly, making 100% of the hardware capability available to the user (and, in this case, Linux-based BIOS and recovery tools). However, there are rare bug reports and general paranoia related to presenting 100% of the ATA hard drive "native" space, rather than the possibly-smaller space that the BIOS chose to present to the user. My thinking is that [someone] should create an optional, ATA-specific device mapper module. This module would layer on top of an ATA block device, and present two block devices: the BIOS-presented space, and the HPA. Such a module would make it trivial for users to ensure that partition tables and RAID metadata formats know what the BIOS (rather than underlying hard drive) considers to be end-of-disk. Comments? Questions? Am I completely insane? ;-) Jeff