From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752320Ab1HZOrO (ORCPT ); Fri, 26 Aug 2011 10:47:14 -0400 Received: from lulu.zabbo.net ([69.168.54.52]:44579 "EHLO lulu.zabbo.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751071Ab1HZOrK (ORCPT ); Fri, 26 Aug 2011 10:47:10 -0400 X-Greylist: delayed 345 seconds by postgrey-1.27 at vger.kernel.org; Fri, 26 Aug 2011 10:47:09 EDT Date: Fri, 26 Aug 2011 07:41:24 -0700 From: Zach Brown To: Marco Stornelli Cc: Dave Chinner , Andreas Dilger , Christoph Hellwig , Josef Bacik , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, xfs@oss.sgi.com, viro@zeniv.linux.org.uk, dchinner@redhat.com Subject: Re: [PATCH] xfstests 255: add a seek_data/seek_hole tester Message-ID: <20110826144124.GA17519@lulu.zabbo.net> References: <1309275199-10801-1-git-send-email-josef@redhat.com> <1309275199-10801-5-git-send-email-josef@redhat.com> <20110825060632.GA9933@infradead.org> <20110825064039.GO3162@dastard> <0A267E55-7772-438D-B6A7-89B73020F311@dilger.ca> <20110826013528.GW3162@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > Hole: a range of the file that contains no data or is made up > > entirely of  NULL (zero) data. Holes include preallocated ranges of > > files that have not had actual data written to them. > No for me. A hole is made up of zero data? It's a strange definition > for me. It's a very natural definition for me. It mirrors the behaviour of read() of sparse data inside i_size that file system authors already have to consider. It's also a reminder for people that this interface is about avoiding reading zeros. Systems that track contents can do this for files that had tons of zeros written. The data is there but the app is specifically asking us to skip it by using SEEK_DATA. - z