From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031296AbXDZPys (ORCPT ); Thu, 26 Apr 2007 11:54:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031293AbXDZPys (ORCPT ); Thu, 26 Apr 2007 11:54:48 -0400 Received: from smtp1.cc.ksu.edu ([129.130.7.15]:43336 "EHLO smtp1.cc.ksu.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031294AbXDZPyp (ORCPT ); Thu, 26 Apr 2007 11:54:45 -0400 Message-ID: <4630CAEC.2050909@ksu.edu> Date: Thu, 26 Apr 2007 10:53:16 -0500 From: Amit Gud User-Agent: Thunderbird 1.5.0.10 (X11/20070221) MIME-Version: 1.0 To: Jeff Dike CC: Valerie Henson , Nikita Danilov , David Lang , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, riel@surriel.com, zab@zabbo.net, arjan@infradead.org, suparna@in.ibm.com, brandon@ifup.org, karunasagark@gmail.com Subject: Re: [RFC][PATCH] ChunkFS: fs fission for faster fsck References: <17965.60841.900376.524639@gargle.gargle.HOWL> <17966.23512.363955.141489@gargle.gargle.HOWL> <17967.15531.450627.972572@gargle.gargle.HOWL> <20070425224710.GB16129@nifty> <20070426141455.GA6155@c2.user-mode-linux.org> In-Reply-To: <20070426141455.GA6155@c2.user-mode-linux.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeff Dike wrote: > How about this case: > > Growing file starts in chunk A. > Overflows into chunk B. > Delete file in chunk A. > Growing file overflows chunk B and spots new free space in > chunk A (and nothing anywhere else) > Overflows into chunk A > Delete file in chunk B. > Overflow into chunk B again. > > Maybe this is not realistic, but in the absence of a mechanism to pull > data back from an overflow chunk, it seems at least a theoretical > possibility that there could be > 1 continuation inodes per file per > chunk. > Preventive measures are taken to limit only one continuation inode per file per chunk. This can be done easily in the chunk allocation algorithm for disk space. Although I'm not quite sure what you mean by "Delete file in chunk A". If you are referring to same file thats growing, then deletion is not possible, because individual parts of any file in any chunk cannot be deleted. AG -- May the source be with you. http://www.cis.ksu.edu/~gud