From: Theodore Tso Subject: Re: Review of ext4-online-defrag-check-for-freespace-fragmentation.patch Date: Sat, 13 Sep 2008 22:10:24 -0400 Message-ID: <20080914021024.GB30537@mit.edu> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Takashi Sato , linux-ext4@vger.kernel.org To: a-fujita@rs.jp.nec.com Return-path: Received: from BISCAYNE-ONE-STATION.MIT.EDU ([18.7.7.80]:47046 "EHLO biscayne-one-station.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753137AbYINCKb (ORCPT ); Sat, 13 Sep 2008 22:10:31 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sat, Sep 13, 2008 at 06:16:42PM -0400, Theodore Ts'o wrote: > > Secondly, some of the ioctl numbers chosen by the defrag patches overlap > other, already existing patches. This is something we will need to fix, > long term. For now, folks should know that we can't count on the ioctl > numbers being stable, since we will probably need to move them. Note: I have done this in the version of the defrag patches in the ext4 patch queue, where all of the ioctl's introduced by the defrag patches have been renumbered starting at 15, to avoid conflicts with other ioctls that either exist already or could be introduced in the future. If you don't mind, we can also merge up some of the patches that have been inserted in the patch queue, and then you can start working from the modified version in the patch queue. The other way to move forward is that we can start creating new ioctl's that are more general and have carefully designed interfaces, and then as the replacement ioctl's are created, the defrag patches can be shortened and the on-line defrag command modified to use the new ioctl's. - Ted