Philipp Hahn
2012-Feb-23 13:23 UTC
Re: backport "ext4: serialize unaligned asynchronous DIO" to 2.6.32
Hello Ted, hello Eric, On Monday February 7th 2011 16:59:36 Ted Ts''o wrote:> commit 7520bb0f2980ef79d17dcbec2783760b37490ffc > Author: Eric Sandeen <sandeen@redhat.com> > Date: Mon Feb 7 10:57:28 2011 -0500 > > ext4: serialize unaligned asynchronous DIO > > ext4 has a data corruption case when doing non-block-aligned > asynchronous direct IO into a sparse file, as demonstrated > by xfstest 240.I hope you remember that bug, because I encountered this data corruption bug on Debians 2.6.32(.51) kernel as well. On the other hand RedHat seems to have back-ported that fix to RHEL5 (2.6.18) and probably RHEL6 (2.6.32) as well, but I don''t have a subscription, so I can''t verify that: <http://rpmfind.net/linux/RPM/centos/updates/5.7/x86_64/RPMS/kernel-devel-2.6.18-274.12.1.el5.x86_64.html> <https://bugzilla.redhat.com/show_bug.cgi?id=689830> The Xen-people also encountered it and asked for someone to backport it: <http://osdir.com/ml/xen-development/2011-07/msg00474.html> I tried to backport it from 2.6.38~rc5 to 2.6.32.51 and thus far it seems to fix the bug. But several other things were re-named and re-organized between those versions, so it was not slreight forward. Since I''m no ext4 expert, I''d like to ask you to have a look at this backport. Is it sound or are there some tests I can throw at it to get it tested more thoroughly? Does is classify for <mailto:stable@vger.kernel.org>? Thanks in advance Philipp Hahn -- Philipp Hahn Open Source Software Engineer hahn@univention.de Univention GmbH Linux for Your Business fon: +49 421 22 232- 0 Mary-Somerville-Str.1 D-28359 Bremen fax: +49 421 22 232-99 http://www.univention.de/ _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Eric Sandeen
2012-Feb-23 15:15 UTC
Re: backport "ext4: serialize unaligned asynchronous DIO" to 2.6.32
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2/23/12 7:23 AM, Philipp Hahn wrote:> Hello Ted, hello Eric, > > On Monday February 7th 2011 16:59:36 Ted Ts''o wrote: >> commit 7520bb0f2980ef79d17dcbec2783760b37490ffcupstream is actually e9e3bcecf44c04b9e6b505fd8e2eb9cea58fb94d but you probably knew that.>> Author: Eric Sandeen <sandeen@redhat.com> >> Date: Mon Feb 7 10:57:28 2011 -0500 >> >> ext4: serialize unaligned asynchronous DIO >> >> ext4 has a data corruption case when doing non-block-aligned >> asynchronous direct IO into a sparse file, as demonstrated >> by xfstest 240. > > I hope you remember that bug, because I encountered this data corruption bug > on Debians 2.6.32(.51) kernel as well.I remember it well ;) I also backported it to RHEL6, but that "2.6.32" kernel also had a few of ext4 updates. Still, grabbing a centos6 kernel src.rpm and looking might help you. FWIW I also backported f46c483357c2d87606bbefb511321e3efd4baae0 and f2d28a2ebcb525a6ec7e2152106ddb385ef52b73 as helpers.> On the other hand RedHat seems to have back-ported that fix to RHEL5 (2.6.18) > and probably RHEL6 (2.6.32) as well, but I don''t have a subscription, so I > can''t verify that: > <http://rpmfind.net/linux/RPM/centos/updates/5.7/x86_64/RPMS/kernel-devel-2.6.18-274.12.1.el5.x86_64.html> > <https://bugzilla.redhat.com/show_bug.cgi?id=689830>615309 is the RHEL6 bug. Sadly it''s marked private.> The Xen-people also encountered it and asked for someone to backport it: > <http://osdir.com/ml/xen-development/2011-07/msg00474.html> > > I tried to backport it from 2.6.38~rc5 to 2.6.32.51 and thus far it seems to > fix the bug. But several other things were re-named and re-organized between > those versions, so it was not slreight forward. > > Since I''m no ext4 expert, I''d like to ask you to have a look at this backport. > Is it sound or are there some tests I can throw at it to get it tested more > thoroughly?xfstests test #240 tests it specifically: # FS QA Test No. 240 # # Test that non-block-aligned aio+dio into holes does not leave # zero''d out portions of the file # # QEMU IO to a file-backed device with misaligned partitions # can send this sort of IO # # This test need only be run in the case where the logical block size # of the device can be smaller than the file system block size. and running all the xfstests over your result would probably be good. FWIW, there was a related xfs fix as well: https://bugzilla.redhat.com/show_bug.cgi?id=669272 that one''s not marked private <eyeroll>> Does is classify for <mailto:stable@vger.kernel.org>?probably so. To be honest I am really pressed for time right now, and this was somewhat tricky code. I won''t be able to review it right now, anyway, but can try to get to it at some point if my schedule lightens up... :( - -Eric> Thanks in advance > Philipp Hahn-----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJPRlgFAAoJECCuFpLhPd7gU58QAJwAzv2e9WVT2zs741Jhv0Fl NCAJ7t7+EYECA5Qtbzm/LCojmvf2mYKVA2MmHiLIG0jxSAX6DQ+bHsjx0N3DbFCA nabZFBwjiNfbII3ut4lHTWXfi6hZ0yqs6/qZTCnm4janwQN9ffR7+kuwTfuJGTaI a0pelgiXQTIVQcx/togd9qezrEwVGd/7Z/sw67o1/hpc76fsELXYnZVkQ4jzXKwc gvAgjFKSdkY0sMCq/owwiA6lgZydMeGzkXYbDlvYx7lfPp6n8ZPpupa2UKAeSF/P 4T8cweTK/XNvlr7KcXx9zHoD3ZLRTYaVvvIlaOa5n0S+v71wGV/AOV2wLNeK3s2x jn91Zsf1sKTpvUQsh5P1UZKgOEXVgQ+gu4+15Ggk5LPOrSd8j4wjrGbrHHu4MfRv udLZP1lE+RINflzdkL6nx6UeeI+X4LOU5McjSgs4gaKInTK9U090vpsCDijEK+mJ ku9nfX+pBiXQgcHFA8fTe0KwnBxvA+AuY0n4w4zzj96bh9tqlYK2MH3qfVJTrMrs pl6gZQTUbt8/UwaP8ooa0gBBG9aGVaBsRtBng9hqIb5vU+TImR8PBlL3QQZPvcZa g+wYq3UmIl5z+A17Ify37FgbU6lsuFmleU0fRglV/ofAywMGatKNUJZn4yz+7QTv ADMfCQ8Gnpy8Ue+LxQkO =cYPJ -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html