From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755476Ab2LSUps (ORCPT ); Wed, 19 Dec 2012 15:45:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41182 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755121Ab2LSUpe (ORCPT ); Wed, 19 Dec 2012 15:45:34 -0500 Message-ID: <50D22766.9090107@redhat.com> Date: Wed, 19 Dec 2012 21:45:26 +0100 From: Milan Broz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:5.0) Gecko/20110807 Thunderbird/5.0 MIME-Version: 1.0 To: Mike Snitzer CC: "Martin K. Petersen" , Joseph Salisbury , Kernel Team , linux-kernel@vger.kernel.org, jgarzik@redhat.com, JBottomley@Parallels.com Subject: Re: [v3.7 Regression] [SCSI] sd: Implement support for WRITE SAME References: <50CB8C74.3090102@canonical.com> <50D0C971.1000907@canonical.com> <20121219195801.GA14456@redhat.com> In-Reply-To: <20121219195801.GA14456@redhat.com> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/19/2012 08:58 PM, Mike Snitzer wrote: > On Wed, Dec 19 2012 at 11:58am -0500, > Martin K. Petersen wrote: > >>>>>>> "Joseph" == Joseph Salisbury writes: >> >> Joseph> I captured the netconsole output from boot until I reproduced >> Joseph> the bug. The RIP points to kcryptd_crypt_write_io_submit() in >> Joseph> ~/drivers/md/dm-crypt.c. The output can be seen at: >> >> I'm thinking that dm-crypt should probably set max_write_same_sectors to >> 0. It doesn't really make much sense for a crypto driver to pass that >> command through. IMHO WRITE_SAME doesn't not make sense in encrypted storage. The same sectors in plaintext are _not_ the same in ciphertext. NEVER. (If so, you have a security problem.) It must be disabled in dmcrypt explicitly then (max_write_same_sectors?). Is it only dmcrypt, or encrypted fs are affected too? Milan