From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p5THAwvg124909 for ; Wed, 29 Jun 2011 12:10:58 -0500 Received: from rcsinet10.oracle.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 8152DE259D7 for ; Wed, 29 Jun 2011 10:10:57 -0700 (PDT) Received: from rcsinet10.oracle.com (rcsinet10.oracle.com [148.87.113.121]) by cuda.sgi.com with ESMTP id aLUZwPAV33k8VlCZ for ; Wed, 29 Jun 2011 10:10:57 -0700 (PDT) Message-ID: <4E0B5C6F.3060803@oracle.com> Date: Wed, 29 Jun 2011 10:10:07 -0700 From: Sunil Mushran MIME-Version: 1.0 Subject: Re: [PATCH] xfstests 255: add a seek_data/seek_hole tester References: <1309275199-10801-1-git-send-email-josef@redhat.com> <1309275199-10801-5-git-send-email-josef@redhat.com> <20110629065306.GC1026@dastard> <20110629074021.GA26086@infradead.org> In-Reply-To: <20110629074021.GA26086@infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, Josef Bacik , xfs@oss.sgi.com, viro@ZenIV.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org On 06/29/2011 12:40 AM, Christoph Hellwig wrote: > On Wed, Jun 29, 2011 at 04:53:07PM +1000, Dave Chinner wrote: >> On Tue, Jun 28, 2011 at 11:33:19AM -0400, Josef Bacik wrote: >>> This is a test to make sure seek_data/seek_hole is acting like it does on >>> Solaris. It will check to see if the fs supports finding a hole or not and will >>> adjust as necessary. >> So I just looked at this with an eye to validating an XFS >> implementation, and I came up with this list of stuff that the test >> does not cover that I'd need to test in some way: >> >> - files with clean unwritten extents. Are they a hole or >> data? What's SEEK_DATA supposed to return on layout like >> hole-unwritten-data? i.e. needs to add fallocate to the >> picture... >> >> - files with dirty unwritten extents (i.e. dirty in memory, >> not on disk). They are most definitely data, and most >> filesystems will need a separate lookup path to detect >> dirty unwritten ranges because the state is kept >> separately (page cache vs extent cache). Plenty of scope >> for filesystem specific bugs here so needs a roubust test. > The discussion leading up to the resurrection of SEEK_HOLE/SEEK_DATA > was pretty much about that point. The conclusion based on the Sun > documentation and common sense was that SEEK_DATA may only consider > unwritten extents as hole if the filesystem has a way to distinguish > plain unwritten extents and those that have been dirtied. Else it > should be considered data. > > Testing for making sure dirty preallocated areas aren't wrongly > reported sounds relatively easy, the rest falls into implementation > details, which imho is fine. Not reporting preallocated extents > as holes just is a quality of implementation issue and not a bug. I agree. And if I might add my 2 cents that it would be much easier if we added another test that created files with all the worrisome boundary conditions and used SEEK_DATA/HOLE to copy the files and compared using md5sum. This would be far easier than one that expects a certain pos for each operation. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs