From: Christoph Hellwig Subject: Re: [Cluster-devel] fallocate vs O_(D)SYNC Date: Wed, 16 Nov 2011 08:42:34 -0500 Message-ID: <20111116134234.GA24258@infradead.org> References: <20111116084256.GA22963@infradead.org> <1321436588.2713.5.camel@menhir> <20111116105413.GA2916@quack.suse.cz> <20111116124550.GA11650@infradead.org> <20111116133915.GD8195@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Steven Whitehouse , linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, mfasheh@suse.com, jlbec@evilplan.org, cluster-devel@redhat.com To: Jan Kara Return-path: Received: from 173-166-109-252-newengland.hfc.comcastbusiness.net ([173.166.109.252]:42560 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757225Ab1KPNmh (ORCPT ); Wed, 16 Nov 2011 08:42:37 -0500 Content-Disposition: inline In-Reply-To: <20111116133915.GD8195@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Nov 16, 2011 at 02:39:15PM +0100, Jan Kara wrote: > > This would work fine with XFS and be equivalent to what it does for > > O_DSYNC now. But I'd rather see every filesystem do the right thing > > and make sure the update actually is on disk when doing O_(D)SYNC > > operations. > OK, I don't really have a strong opinion here. Are you afraid that just > calling fsync() need not be enough to push all updates fallocate did to > disk? No, the point is that you should not have to call fsync when doing O_SYNC I/O. That's the whole point of it.