From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [PATCH RESEND] ubifs: Introduce a mount option of force_atime. Date: Wed, 24 Jun 2015 10:33:35 +1000 Message-ID: <20150624003335.GG22807@dastard> References: <1433831809.28854.17.camel@sauron.fi.intel.com> <55769D97.3010602@nod.at> <5577AC03.9060909@cn.fujitsu.com> <1433928078.14092.1.camel@sauron.fi.intel.com> <55780D1C.6080907@cn.fujitsu.com> <1433931934.14092.11.camel@sauron.fi.intel.com> <557812A4.8020409@cn.fujitsu.com> <1433934324.14092.15.camel@sauron.fi.intel.com> <55892D18.3020203@cn.fujitsu.com> <1435056240.7659.69.camel@sauron.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dongsheng Yang , Richard Weinberger , linux-mtd@lists.infradead.org, adrian.hunter@intel.com, linux-fsdevel@vger.kernel.org To: Artem Bityutskiy Return-path: Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:49827 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754891AbbFXAgC (ORCPT ); Tue, 23 Jun 2015 20:36:02 -0400 Content-Disposition: inline In-Reply-To: <1435056240.7659.69.camel@sauron.fi.intel.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Jun 23, 2015 at 01:44:00PM +0300, Artem Bityutskiy wrote: > On Tue, 2015-06-23 at 17:55 +0800, Dongsheng Yang wrote: > > In short, I think force_atime to ubifs is the choice from my opinion. > > So will we end up with this: > > -o - no atime support > -o atime - no atime support > -o noatime - same, no atime support > -o force_atime - full atime support > -o relatime - relative atime support > -o lazyatime - lazy atime support > IOW, atime/noatime mount options have no effect on UBIFS. To have full > atime support - people have to use "force_atime". And then the rest of > the standard options are supported. That's the exact semantics of the standard -o strictatime option. See the mount(8) man page: strictatime Allows to explicitly requesting full atime updates. This makes it possible for kernel to defaults to relatime or noatime but still allow userspace to override it. For more details about the default system mount options see /proc/mounts. It's passed down to the kernel via the MS_STRICTATIME flag. All you need to do is make ubifs aware of this flag... Cheers, Dave. -- Dave Chinner david@fromorbit.com From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z7Yfw-0005Dm-Oo for linux-mtd@lists.infradead.org; Wed, 24 Jun 2015 00:36:25 +0000 Date: Wed, 24 Jun 2015 10:33:35 +1000 From: Dave Chinner To: Artem Bityutskiy Subject: Re: [PATCH RESEND] ubifs: Introduce a mount option of force_atime. Message-ID: <20150624003335.GG22807@dastard> References: <1433831809.28854.17.camel@sauron.fi.intel.com> <55769D97.3010602@nod.at> <5577AC03.9060909@cn.fujitsu.com> <1433928078.14092.1.camel@sauron.fi.intel.com> <55780D1C.6080907@cn.fujitsu.com> <1433931934.14092.11.camel@sauron.fi.intel.com> <557812A4.8020409@cn.fujitsu.com> <1433934324.14092.15.camel@sauron.fi.intel.com> <55892D18.3020203@cn.fujitsu.com> <1435056240.7659.69.camel@sauron.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435056240.7659.69.camel@sauron.fi.intel.com> Cc: linux-fsdevel@vger.kernel.org, Richard Weinberger , Dongsheng Yang , linux-mtd@lists.infradead.org, adrian.hunter@intel.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Jun 23, 2015 at 01:44:00PM +0300, Artem Bityutskiy wrote: > On Tue, 2015-06-23 at 17:55 +0800, Dongsheng Yang wrote: > > In short, I think force_atime to ubifs is the choice from my opinion. > > So will we end up with this: > > -o - no atime support > -o atime - no atime support > -o noatime - same, no atime support > -o force_atime - full atime support > -o relatime - relative atime support > -o lazyatime - lazy atime support > IOW, atime/noatime mount options have no effect on UBIFS. To have full > atime support - people have to use "force_atime". And then the rest of > the standard options are supported. That's the exact semantics of the standard -o strictatime option. See the mount(8) man page: strictatime Allows to explicitly requesting full atime updates. This makes it possible for kernel to defaults to relatime or noatime but still allow userspace to override it. For more details about the default system mount options see /proc/mounts. It's passed down to the kernel via the MS_STRICTATIME flag. All you need to do is make ubifs aware of this flag... Cheers, Dave. -- Dave Chinner david@fromorbit.com