From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: [RFC] ATA host-protected area (HPA) device mapper? Date: Thu, 08 Jun 2006 23:43:36 -0400 Message-ID: <4488EE68.9000605@garzik.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: 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 In-Reply-To: <4488E6F6.10306@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: linux-ide@vger.kernel.org Cc: "zhao, forrest" , htejun@gmail.com, randy_dunlap , Alan Cox , Linux Kernel 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