From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eryu Guan Subject: generic/346 fails on ext4 DAX mount Date: Fri, 2 Jun 2017 13:33:19 +0800 Message-ID: <20170602053319.GF23805@eguan.usersys.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , Ross Zwisler , Xiong Zhou To: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33174 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750747AbdFBFdV (ORCPT ); Fri, 2 Jun 2017 01:33:21 -0400 Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi all, I occasionally hit generic/344 and generic/346 failures when testing 4.12-rc[1-3] kernels on ext4 DAX mount. FSTYP -- ext4 PLATFORM -- Linux/x86_64 hp-xl420gen9-01 4.12.0-rc3 MKFS_OPTIONS -- /dev/pmem2 MOUNT_OPTIONS -- -o dax -o context=system_u:object_r:root_t:s0 /dev/pmem2 /mnt/testarea/scratch generic/344 1s ... 1s generic/346 1s ... - output mismatch (see /var/lib/xfstests/results//generic/346.out.bad) --- tests/generic/346.out 2017-05-24 10:13:38.592436565 -0400 +++ /var/lib/xfstests/results//generic/346.out.bad 2017-06-01 12:46:50.122007818 -0400 @@ -10,7 +10,8 @@ INFO: sz = 1048576 INFO: thread 0 created INFO: thread 1 created -INFO: 0 error(s) detected +ERROR: thread 0, offset 000ff400, 00000000 != 7f1068063700 +INFO: 1 error(s) detected INFO: ftruncate test... INFO: sz = 1048576 And it seems generic/346 is easer to hit, usually it can be reproduced within 20 iterations on 4.12-rc kernels. At first I thought it was a regression introduced in 4.12-rc1, but after two failed bisects (pointed first bad to unrelated networking patch), I enlarged the iteration count to 5000 and found that generic/346 failure can also be seen on 4.11 and 4.10 kernel. I haven't tried other old kernels yet. It's just much harder to hit on 4.10/4.11 kernels (need hundreds of iterations). But the failure could only be reproduced with ext4 DAX mount, XFS DAX mount survived 5000 runs of generic/346 on 4.12-rc3 kernel. I was testing with pmem device created by memmap kernel param "memmap=10G!5G memmap=15G!15G", but it can be reproduced with brd ramdisk too. If more info is needed please let me know. Thanks, Eryu