From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 15 Sep 2001 15:19:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 15 Sep 2001 15:19:01 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:48710 "EHLO flinx.biederman.org") by vger.kernel.org with ESMTP id ; Sat, 15 Sep 2001 15:18:44 -0400 To: Byron Stanoszek Cc: Subject: Re: Strange /dev/loop behavior In-Reply-To: From: ebiederm@xmission.com (Eric W. Biederman) Date: 15 Sep 2001 13:10:24 -0600 In-Reply-To: Message-ID: User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.5 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Byron Stanoszek writes: > Is there any known method of copying/compressing the loopback-mounted file- > system that always guarantees consistency after a sync, without requiring the > fs to be unmounted first? Mounting read-only and then syncing might do it. Going directly to the block device on 2.4.x is not supported when the filesystem is mounted. This is because the page cache is not coherent with the block cache, and there are now plans to make this the case. In general this won't work anyway because some other program might be modifying your fs while you read the block device. Eric