From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id mB50cFM6017069 for ; Thu, 4 Dec 2008 18:38:18 -0600 Received: from one.firstfloor.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D13FD16AF1A1 for ; Thu, 4 Dec 2008 16:38:13 -0800 (PST) Received: from one.firstfloor.org (one.firstfloor.org [213.235.205.2]) by cuda.sgi.com with ESMTP id lU6zXNJWmehdgcjw for ; Thu, 04 Dec 2008 16:38:13 -0800 (PST) Date: Fri, 5 Dec 2008 01:48:49 +0100 From: Andi Kleen Subject: Re: Device loses barrier support (was: Fixed patch for simple barriers.) Message-ID: <20081205004849.GX6703@one.firstfloor.org> References: <20081204100050.GN6703@one.firstfloor.org> <20081204142015.GQ6703@one.firstfloor.org> <20081204145810.GR6703@one.firstfloor.org> <20081204174838.GS6703@one.firstfloor.org> <20081204221551.GV6703@one.firstfloor.org> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Mikulas Patocka Cc: Andi Kleen , linux-kernel@vger.kernel.org, xfs@oss.sgi.com, Andi Kleen , Alasdair G Kergon , Milan Broz > And if barriers fail at random points, the user can't turn on disk cache > anyway (he would get data corruption if barrier write failed and hardware I think we already established earlier in the thread that there is no disk corruption > > > I'm wondering, where in fsync() does Linux wait for hardware disk cache to > > > be flushed? Isn't there a bug that fsync() will return before the cache is > > > flushed? I couldn't really find it. The last thing do_fsync calls is > > > filemap_fdatawait and it doesn't do cache flush (blkdev_issue_flush). > > > > At least in fsync() on journaling fs the metadata update should push it. > > > > -Andi > > And what about fdatasync()? I don't know. The surest way to find out is to instrument it and try. -Andi -- ak@linux.intel.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs