From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christof Schmitt Subject: Re: Wrong DIF guard tag on ext2 write Date: Mon, 31 May 2010 13:34:47 +0200 Message-ID: <20100531113447.GB16260@schmichrtp.mainz.de.ibm.com> References: <20100531112817.GA16260@schmichrtp.mainz.de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20100531112817.GA16260@schmichrtp.mainz.de.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org To: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On Mon, May 31, 2010 at 01:28:17PM +0200, Christof Schmitt wrote: > When running tests with an ext2 filesystem on a device using DIF/DIX > integrity data, i sometimes see invalid guard tags on write requests. > To track down the problem, i patched the function sd_prep_fn in sd.c > to verify the IP checksums in the guard tags against the actual data. > Sometimes there is a mismatch and the write request fails when the HBA > checks the guard tag. > > Since the guard tags are created in Linux, it seems that the data > attached to the write request changes between the generation in > bio_integrity_generate and the call to sd_prep_fn. > > Using ext3 or ext4 instead of ext2 does not show the problem. > > There is a bugzilla open at Redhat with the same symptom, but there is > no data or activity: > https://bugzilla.redhat.com/show_bug.cgi?id=574266 > > What would be the best way to track down this problem? One more thing: The test is running with a 2.6.34 kernel, the problem in the bugzilla is reported for 2.6.33. Christof Schmitt