From: Eryu Guan Subject: Re: [PATCH] fstests: generic: Check if cycle mount and sleep can affect fiemap result Date: Fri, 7 Apr 2017 13:02:58 +0800 Message-ID: <20170407050258.GO22845@eguan.usersys.redhat.com> References: <20170403070923.18518-1-quwenruo@cn.fujitsu.com> <20170405023526.GS22845@eguan.usersys.redhat.com> <20170406162616.zsnbgx6vy2fgugmq@thunk.org> <36663e81-9520-0c52-5e72-1d54ddbfb0b7@sandeen.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Qu Wenruo , linux-btrfs@vger.kernel.org, fstests@vger.kernel.org, linux-ext4@vger.kernel.org To: Eric Sandeen , Theodore Ts'o Return-path: Content-Disposition: inline In-Reply-To: <36663e81-9520-0c52-5e72-1d54ddbfb0b7@sandeen.net> Sender: fstests-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, Apr 06, 2017 at 11:28:01AM -0500, Eric Sandeen wrote: > On 4/6/17 11:26 AM, Theodore Ts'o wrote: > > On Wed, Apr 05, 2017 at 10:35:26AM +0800, Eryu Guan wrote: > >> > >> Test fails with ext3/2 when driving with ext4 driver, fiemap changed > >> after umount/mount cycle, then changed back to original result after > >> sleeping some time. An ext4 bug? (cc'ed linux-ext4 list.) > > > > I haven't had time to look at this, but I'm not sure this test is a > > reasonable one on the face of it. > > > > A file system may choose to optimize a file's extent tree for whatever > > reason it wants, whenever it wants, including on an unmount --- and > > that would not be an invalid thing to do. So to have an xfstests that > > causes a test failure if a file system were to, say, do some cleanup > > at mount or unmount time, or when the file is next opened, to merge > > adjacent extents together (and hence change what is returned by > > FIEMAP) might be strange, or even weird --- but is this any of user > > space's business? Or anything we want to enforce as wrong wrong wrong > > by xfstests? So I was asking for a review from ext4 side instead of queuing it for next xfstests update :) > > I had the same question. If the exact behavior isn't defined anywhere, > I don't know what we can be testing, TBH. Agreed, I was about to ask for the expected behavior today if there was no new review comments on this patch. Thanks for the comments and review! Eryu