From: Theodore Tso Subject: Re: [RFC][PATCH 0/12]ext4: online defrag (ver 0.95) Date: Wed, 1 Oct 2008 17:20:11 -0400 Message-ID: <20081001212011.GG10080@mit.edu> References: <48DDE025.2090207@rs.jp.nec.com> <20081001004053.GD3160@webber.adilger.int> <20081001184545.GA2096@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andreas Dilger , Akira Fujita , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Christoph Hellwig Return-path: Received: from www.church-of-our-saviour.ORG ([69.25.196.31]:51920 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751705AbYJAVUS (ORCPT ); Wed, 1 Oct 2008 17:20:18 -0400 Content-Disposition: inline In-Reply-To: <20081001184545.GA2096@infradead.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Oct 01, 2008 at 02:45:45PM -0400, Christoph Hellwig wrote: > On Tue, Sep 30, 2008 at 05:40:54PM -0700, Andreas Dilger wrote: > > Instead of implementing an EXT4_IOC_FIEMAP_INO ioctl, what we had implemented > > is an EXT4_IOC_WRAPPER, which takes as arguments the inode number and the > > ioctl command + original ioctl data. This allows inode ioctls to be called > > against the filesystem root for arbitrary inodes, and doesn't require new > > implementation for each ioctl: > > Or just provide more generic open by handle functionality. Shouldn't be > too much of a problem to do it in the VFS by reusing the exportfs code. > A while back I had implemented an "open by inode" patch for a friend who needed it for their startup. I never posted it because (a) even though it was only optionally enabled via a mount option, if you allow non-root users to access it, it blows a whole through traditional unix permissions semantics (i.e., a mode 700 directory no longer protects files underneath that directory), and (b) I was sure that Al Viro would consider the hacks that I needed to make it work to be far too ugly to live. :-) - Ted