From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266787AbUFYQZx (ORCPT ); Fri, 25 Jun 2004 12:25:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266789AbUFYQZx (ORCPT ); Fri, 25 Jun 2004 12:25:53 -0400 Received: from gprs214-83.eurotel.cz ([160.218.214.83]:50560 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S266787AbUFYQZw (ORCPT ); Fri, 25 Jun 2004 12:25:52 -0400 Date: Fri, 25 Jun 2004 18:25:37 +0200 From: Pavel Machek To: Horst von Brand Cc: Amit Gud , alan , "Fao, Sean" , linux-kernel@vger.kernel.org Subject: Re: Elastic Quota File System (EQFS) Message-ID: <20040625162537.GA6201@elf.ucw.cz> References: <004e01c45abd$35f8c0b0$b18309ca@home> <200406251444.i5PEiYpq008174@eeyore.valparaiso.cl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200406251444.i5PEiYpq008174@eeyore.valparaiso.cl> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > Case closed, anyway. It belongs in the kernel only if there is no > reasonable way to do it in userspace. But... there's no reasonable way to do this in userspace. Two pieces of kernel support are needed: 1) some way to indicate "this file is elastic" (okay perhaps xattrs can do this already) and either 2a) file selection/deletion in kernel or 2b) assume that disk does not fill up faster than 1GB/sec, allways keep 1GB free, make "deleting" daemon poll each second [ugly, unreliable] or 2c) just before returning -ENOSPC, synchronously tell userspace to free space, and retry the operation. BTW 2c) would be also usefull for undelete. Unfortunately 2c looks very complex, too; it might be easier to do 2a than 2c. Pavel -- People were complaining that M$ turns users into beta-testers... ...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!