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, 2 Nov 2002 03:51:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 2 Nov 2002 03:51:54 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:34827 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id ; Sat, 2 Nov 2002 03:51:52 -0500 Message-ID: <3DC3937F.80504@pobox.com> Date: Sat, 02 Nov 2002 03:57:35 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20021003 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Theodore Ts'o" CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH] 2/11 Ext2/3 Updates: Extended attributes, ACL, etc. References: <3DBEC3E6.9050908@pobox.com> <20021101032159.GA12031@think.thunk.org> 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 Theodore Ts'o wrote: >I'm not sure ext2meta will be sufficient. It's not just a matter of >modifying the on-disk metadata, as would be needed for defrag, but I >would also need to modify some of the in-core data structions in the >ext2/3 filesystem data structures. For example, when you resize the >filesystem, you need to increase the number of group descriptors, >which means you need to kmalloc, copy, and then kfree sbi->group_desc >out from under the mounted filesystem. > >No doubt ext2meta could be modified so it could "reach out and touch" >internal ext2/3 fileststem data structures in core. But the locking >issues involved get really messy. > > Like Al mentioned... any merge of ext[23]meta would be inside ext[23].o, so it would be a first class object and not some random module sticking its fingers in there. I looked at the locking issue too (though admittedly not in-depth for filesystem resize), and it's not different at all from existing locking, both in 2.4.x and 2.5.x. It's intentionally pretty darn compatible with existing locking :) I'll post a patch in the next couple weeks... Jeff