From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZM8jT-00088Q-4G for linux-mtd@lists.infradead.org; Mon, 03 Aug 2015 05:56:19 +0000 Date: Mon, 3 Aug 2015 15:55:37 +1000 From: Dave Chinner To: Dongsheng Yang Cc: eguan@redhat.com, fstests@vger.kernel.org, dedekind1@gmail.com, richard.weinberger@gmail.com, linux-mtd@lists.infradead.org Subject: Re: [PATCH 2/5] xfstest: generic/219 add _require_odirect Message-ID: <20150803055537.GS3902@dastard> References: <1438236417-24612-1-git-send-email-yangds.fnst@cn.fujitsu.com> <1438236417-24612-3-git-send-email-yangds.fnst@cn.fujitsu.com> <20150803035909.GP3902@dastard> <55BEF5A2.6090606@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55BEF5A2.6090606@cn.fujitsu.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Aug 03, 2015 at 01:01:22PM +0800, Dongsheng Yang wrote: > On 08/03/2015 11:59 AM, Dave Chinner wrote: > >On Thu, Jul 30, 2015 at 02:06:54PM +0800, Dongsheng Yang wrote: > >>generic/219 is testing quota in three use cases including > >>Direct I/O. So we have to add a dependence to odirect in > >>this test. > > > >Hmmm - you've modified on only 2 tests here in this patch series > >that use direct IO. There are many more - just looking for direct IO > >comments, these generic tests use direct IO in some way, and there > >are others that such usage is not obvious (e.g. this patch to > >generic/219): > > > >generic/091 > >generic/113 > >generic/130 > >generic/214 > >generic/224 > >generic/263 > >shared/272 > > > >And all the aio/dio tests: > > > >generic/036 > >generic/198 > >generic/207 > >generic/208 > >generic/209 > >generic/210 > >generic/211 > >generic/212 > >generic/239 > >generic/240 > >generic/323 > > > >And there are others that run fio that uses DIO, too, like > > > >generic/299 > >generic/300 > > > >And so on. I haven't even looked at all the fsx tests that might > >use DIO, and I know that some of them are not listed above... > > > >On the whole, I think ubifs would be better to implement DIO via > >buffered fallback that to make us have to annotate every test that > >uses DIO in some way... > > Fair point. Yes, It's difficult to find out all the tests which > would use DIO. > > And we are discussing about dio in ubifs. > > So if you are strongly rejecting this kind of change, I will drop > this patch in my next version. I would say "strongy rejecting", more advising a different approach to solve the problem. i.e. with a "return 0" ->direct_IO method, applications that use direct IO won't randomly fail or refuse to run. That seems like a much better (and simpler!) solution compared to chasing down applications that use direct IO and changing them.... Cheers, Dave. -- Dave Chinner david@fromorbit.com