From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eli Carter Subject: Re: File perforation. Date: Wed, 08 Jan 2003 16:56:16 -0600 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <3E1CAC90.6050303@inet.com> References: <3E1CA628.7000002@inet.com> <21551.1042063560@passion.cambridge.redhat.com> <22288.1042065284@passion.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org Return-path: Received: from tex.inetint.com (tex [172.16.99.35]) by zeke.inet.com (8.12.1/8.12.1) with ESMTP id h08MuISt001948 for ; Wed, 8 Jan 2003 16:56:19 -0600 (CST) Received: from harpo.inetint.com (localhost [127.0.0.1]) by tex.inetint.com (8.12.1/8.12.1) with ESMTP id h08MuHO2012863 for ; Wed, 8 Jan 2003 16:56:17 -0600 (CST) To: David Woodhouse List-Id: linux-fsdevel.vger.kernel.org David Woodhouse wrote: > eli.carter@inet.com said: > >> Could you elaborate on the difference between what you want to do and >> sparse files? > > > > No difference. Given a non-sparse file, I want a way to make it sparse. > > Well, I _have_ a way to make it sparse; all I have to do is write out a > single log entry. What I am lacking is a way for the user to tell me to do > so :) > > I'm aware that you can do this by deleting the file and writing out a new > copy. But this is flash and it has a limited number of write cycles; I don't > want to do that. (No answers, just questions... ;) ) On a compressed fs like jffs2, wouldn't a block of 0's compress down to next-to-nothing already? Can the fs recognize a big block of 0's and make it sparse on-the-fly without needing the user to specify it? (On block-based fs's, that might not always be desirable due to out-of-space errors on modifying a file, but for a compressed fs, that's not a new issue.) (Hmm.... If I'm missing something obvious, clue-by-four me and I'll go away. ;) ) Eli --------------------. "If it ain't broke now, Eli Carter \ it will be soon." -- crypto-gram eli.carter(a)inet.com `-------------------------------------------------