From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751497AbdINISF (ORCPT ); Thu, 14 Sep 2017 04:18:05 -0400 Received: from mx2.suse.de ([195.135.220.15]:35044 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751181AbdINISD (ORCPT ); Thu, 14 Sep 2017 04:18:03 -0400 Date: Thu, 14 Sep 2017 10:17:57 +0200 From: Johannes Thumshirn To: Philipp Guendisch Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, damien.lemoal@wdc.com, axboe@kernel.dk, viro@zeniv.linux.org.uk, bart.vanassche@sandisk.com, martin.petersen@oracle.com, hare@suse.de, osandov@fb.com, dan.j.williams@intel.com, ming.lei@redhat.com, linux-kernel@i4.cs.fau.de, Mate Horvath Subject: Re: [PATCH] Support for secure erase functionality Message-ID: <20170914081757.c64qa6pp2zi5hmda@linux-x5ow.site> References: <1505317073-22567-1-git-send-email-philipp.guendisch@fau.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1505317073-22567-1-git-send-email-philipp.guendisch@fau.de> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 13, 2017 at 05:37:53PM +0200, Philipp Guendisch wrote: > This patch adds a software based secure erase option to improve data > confidentiality. The CONFIG_BLK_DEV_SECURE_ERASE option enables a mount > flag called 'sw_secure_erase'. When you mount a volume with this flag, > every discard call is prepended by an explicit write command to overwrite > the data before it is discarded. A volume without a discard compatibility > can be used as well but the discard calls will be enabled for this device > and suppressed after the write call is made. How can this work with CoW filesystems? > > Built against torvalds/linux This should go below the '---' so git am doesn't write it into the changelog. [...] > + if (strcmp(fs_type->name, "ext4") != 0 && > + strcmp(fs_type->name, "btrfs") != 0 && > + strcmp(fs_type->name, "gfs2") != 0 && > + strcmp(fs_type->name, "gfs2meta") != 0 && > + strcmp(fs_type->name, "xfs") != 0 && > + strcmp(fs_type->name, "jfs") != 0) { > + pr_warn("fs: The mounted %s filesystem on drive %s does not generate discards, secure erase won't work", > + fs_type->name, dev_name); > + } > +skip: > +#endif Which filesystems commonly used in production are left afterwards? I'm sorry, but while I get that this sounds like a nice feature for a paper or reasearch project, I don't see why it should be used on production systems at all. Byte, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850