From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:48715 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751795AbcGRSoC (ORCPT ); Mon, 18 Jul 2016 14:44:02 -0400 Subject: Re: [PATCH 0/3] Btrfs: fix free space tree bitmaps+tests on big-endian systems To: Chandan Rajendra , Omar Sandoval References: <48955009.Up9FeqXyzx@localhost.localdomain> <20160715191515.GA13357@vader.DHCP.thefacebook.com> <3006396.dOAW6WHiJC@localhost.localdomain> CC: , From: Chris Mason Message-ID: <399ec92c-9905-0ede-d5b0-ea3b0bf922e4@fb.com> Date: Mon, 18 Jul 2016 14:43:26 -0400 MIME-Version: 1.0 In-Reply-To: <3006396.dOAW6WHiJC@localhost.localdomain> Content-Type: text/plain; charset="windows-1252"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 07/17/2016 08:19 AM, Chandan Rajendra wrote: > On Friday, July 15, 2016 12:15:15 PM Omar Sandoval wrote: >> On Fri, Jul 15, 2016 at 12:34:10PM +0530, Chandan Rajendra wrote: >>> On Thursday, July 14, 2016 07:47:04 PM Chris Mason wrote: >>>> On 07/14/2016 07:31 PM, Omar Sandoval wrote: >>>>> From: Omar Sandoval >>>>> >>>>> So it turns out that the free space tree bitmap handling has always been >>>>> broken on big-endian systems. Totally my bad. >>>>> >>>>> Patch 1 fixes this. Technically, it's a disk format change for >>>>> big-endian systems, but it never could have worked before, so I won't go >>>>> through the trouble of any incompat bits. If you've somehow been using >>>>> space_cache=v2 on a big-endian system (I doubt anyone is), you're going >>>>> to want to mount with nospace_cache to clear it and wait for this to go >>>>> in. >>>>> >>>>> Patch 2 fixes a similar error in the sanity tests (it's the same as the >>>>> v2 I posted here [1]) and patch 3 expands the sanity tests to catch the >>>>> oversight that patch 1 fixes. >>>>> >>>>> Applies to v4.7-rc7. No regressions in xfstests, and the sanity tests >>>>> pass on x86_64 and MIPS. >>>> >>>> Thanks for fixing this up Omar. Any big endian friends want to try this >>>> out in extended testing and make sure we've nailed it down? >>>> >>> >>> Hi Omar & Chris, >>> >>> I will run fstests with this patchset applied on ppc64 BE and inform you about >>> the results. >>> >> >> Thanks, Chandan! I set up my xfstests for space_cache=v2 by doing: >> >> mkfs.btrfs "$TEST_DEV" >> mount -o space_cache=v2 "$TEST_DEV" "$TEST_DIR" >> umount "$TEST_DEV" >> >> and adding >> >> export MOUNT_OPTIONS="-o space_cache=v2" >> >> to local.config. btrfsck also needs the patch here [1]. >> >> > > Hi, > > I did execute the fstests tests suite on ppc64 BE as per above configuration > and there were no new regressions. Also, I did execute fsx (via generic/127) > thrice on the same filesystem instance, > 1. With the unpatched kernel and later > 2. With the patched kernel and again > 3. With the unpatched kernel > ... there were no new regressions when executing the above steps. Thanks Chandan! But I'm a little confused. If the patch is helping, we should be storing bitmaps wrong on disk unpatched. There should be problems going back and forth. -chris