From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cn.fujitsu.com ([59.151.112.132]:23791 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751900AbcGACao (ORCPT ); Thu, 30 Jun 2016 22:30:44 -0400 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 4E7A1498F58F for ; Fri, 1 Jul 2016 10:30:07 +0800 (CST) Subject: Re: [PATCH v2] geceric/362: check truncate can update file size correctly when truncate fails References: <20160623082718.GF3226@eguan.usersys.redhat.com> <20160630082549.27201-1-wangxg.fnst@cn.fujitsu.com> <20160630135237.GG23649@eguan.usersys.redhat.com> From: Wang Xiaoguang Message-ID: <5775D54C.6070001@cn.fujitsu.com> Date: Fri, 1 Jul 2016 10:28:28 +0800 MIME-Version: 1.0 In-Reply-To: <20160630135237.GG23649@eguan.usersys.redhat.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Sender: fstests-owner@vger.kernel.org Content-Transfer-Encoding: quoted-printable To: fstests@vger.kernel.org List-ID: hello, On 06/30/2016 09:52 PM, Eryu Guan wrote: > On Thu, Jun 30, 2016 at 04:25:49PM +0800, Wang Xiaoguang wrote: >> In btrfs, when truncate operation fails for enospc reason, file may st= ill >> have some disk blocks, but it will fail to update filesize accordingly. >> >> Kernel commit c0d2f61 has fixed this bug for btrfs: >> btrfs: fix disk_i_size update bug when ftruncate() fails >> >> Signed-off-by: Wang Xiaoguang >> --- >> v2: move this test to generic test and add comments why testcase >> use reflink. > Thanks for the updated version. Did it fail for you when testing on > unpatched kernel? I ran the test more than 10 times on 4.6 kernel (whic= h > doesn't have the fix) and all passed, as well as RHEL7 kernel. > > Can you please confirm? I tested this case in v4.6-rc7-162-g415b35a and it failed as expected, but I used the newest version btrfs-progs. In RHEL7.2ga, its btrfs-progs version is btrfs-progs-3.19.1-1.el7.x86_64, which is somewhat old. For small fs, it'll enable mixed mode for data and metadata default, so the reflink operation in this test case does not=20 consume enough metadata, truncate operation can still succeed, then test will alw= ays pass. I can create a big fs to have test, but then this fs will have more metadata, which then need more reflink operations to consume metadata and increase the test time greatly. In mkfs.btrfs manpage, there is such description=EF=BC=9A versions up to 4.2.x forced the mixed mode for devices smaller than 1GiB. This has been removed in 4.3+ as it caused some usability issues. Regards, Xiaoguang Wang > > Thanks, > Eryu > >