From: Matt Subject: Re: ext4: Fix data corruption with multi-block writepages support Date: Mon, 7 Feb 2011 18:44:14 +0000 Message-ID: References: <20110207174552.GC3457@thunk.org> <4D503A06.3010403@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Ted Ts'o" , Linux Kernel , linux-ext4 To: Milan Broz Return-path: In-Reply-To: <4D503A06.3010403@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon, Feb 7, 2011 at 6:29 PM, Milan Broz wrote: > On 02/07/2011 06:45 PM, Ted Ts'o wrote: >> On Fri, Feb 04, 2011 at 10:40:47PM +0000, Matt wrote: >>> >>> So that means that the file-corruption which existed until 2.6.37-r= c6 >>> and got triggered (for me) more easily via "dm crypt: scale to >>> multiple CPUs" >>> is fixed now ? >> >> Well, a patch exists for it that will be merged into 2.6.38. >> >>> That should give ext4 a nice speedup for >=3D2.6.38 :) >> >> I'm not going to make it be the default for 2.6.38, since it's fairl= y >> late in the -rc features. =A0People who want it can explicitly enabl= e it >> using the mount option mblk_io_submit, though. =A0(And let me know y= our >> success stories! =A0:-) I will be enabling it as the default in >> 2.6.39-rc1. > > So it was ext4 only bug in ext4_end_bio(), > dm-crypt per-cpu code was just trigger here, right? > > Milan > Hi Milan, Well, that was at least the experience that I made ext4: after Ted had disabled support for multiple page-io submission I observed no data-corruption anymore (it had only appeared on the system-partition, /home - where ext4 also is used or on my backup partitions there was also no problem as far as I can tell) XFS: no corruption observed reiserfs: I can't say for sure since I'm only using it on my /boot part= ition :P for other filesystems I can't say anything - I didn't use additional ones at that time Regards Matt