From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262934AbTDYEVv (ORCPT ); Fri, 25 Apr 2003 00:21:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262945AbTDYEVu (ORCPT ); Fri, 25 Apr 2003 00:21:50 -0400 Received: from terminus.zytor.com ([63.209.29.3]:64191 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S262934AbTDYEVu (ORCPT ); Fri, 25 Apr 2003 00:21:50 -0400 Message-ID: <3EA8BAB0.4080003@zytor.com> Date: Thu, 24 Apr 2003 21:33:52 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3b) Gecko/20030211 X-Accept-Language: en-us, en, sv MIME-Version: 1.0 To: Andreas Dilger CC: linux-kernel@vger.kernel.org Subject: Re: Fix SWSUSP & !SWAP References: <1051182797.2250.10.camel@laptop-linux> <20030424222737.X26054@schatzie.adilger.int> In-Reply-To: <20030424222737.X26054@schatzie.adilger.int> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andreas Dilger wrote: > > This "supersync" already exists, and it is supported by all of the > journaling filesystems for LVM snapshots. This is the VFS method > write_super_lockfs in the ext3/reiserfs/XFS/JFS super_operations. > Not only does it sync the dirty data to disk, but it also forces > the journal to be empty and marks the filesystem clean, so that it > can be snapshotted and read-only mounted (basically equivalent to > unmounting the filesystem). > > Unfortunately, even though the filesystems themselves have supported > this VFS method for a long time, the actual code that calls these > methods (sync_super_lockfs() and unlockfs()) are still only available > as a patch from LVM. The LVM/reiserfs folks have talked about submitting > it to Marcelo for a long time now, but apparently still haven't done so. > I really think this should be made available. Perhaps we should have a sync1() system call which takes a flag set. Then we could have sync1(SYNC_FLUSH_JOURNALS); -hpa