From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262455AbULCRuO (ORCPT ); Fri, 3 Dec 2004 12:50:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262457AbULCRuO (ORCPT ); Fri, 3 Dec 2004 12:50:14 -0500 Received: from ms-smtp-01.texas.rr.com ([24.93.47.40]:57483 "EHLO ms-smtp-01-eri0.texas.rr.com") by vger.kernel.org with ESMTP id S262455AbULCRti (ORCPT ); Fri, 3 Dec 2004 12:49:38 -0500 Message-ID: <41B0A710.5050408@austin.rr.com> Date: Fri, 03 Dec 2004 11:49:04 -0600 From: Steve French User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5) Gecko/20031007 X-Accept-Language: en-us, en MIME-Version: 1.0 To: aia21@cam.ac.uk CC: linux-kernel@vger.kernel.org Subject: Re: performance of filesystem xattrs with Samba4 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 Anton wrote > I have been mulling over in my head for quite a while what > to do about an interface for "advanced ntfs features" but so far I have > always pushed this to the back of my mind. After all no point in > providing advanced features considering we don't even provide full > read-write access yet. I just thought I would mentione NTFS when I saw > >But to answer your question I definitely would envisage an interface to >the kernel driver The same issue has been on my mind for other filesystems too - since I can return similar information to NTFS. The "easy" things to return that could be useful to apps (including Samba4, but also backup apps etc.) include: 1) file creation time 2) "dos" attribute bits 3) perhaps ACL mapping into "POSIX ACL" (getfacl/setfacl's Linux xattr) format from the CIFS/NTFS style. 4) streams (which could be mapped in a few cases to xattrs, but are getting increasingly used and therefore important for certain types of apps - like network backup e.g. to be able to get access to) The first two are in the on disk format already of various filesytems (NTFS, VFAT, even JFS, and would be trivial for me to export in the cifs vfs. I suspect NFSv4 which is similar to CIFS in many ways would also have an easy time of exporting a few of those. The first two of these could of course be simply special casings the reserved xattr name "User.DosAttribute" or equivalent used by Samba4. This has a few advantages - local apps work and migrations to Linux from Windows are easier (as more data is preserved) :) Note that NTFS now has a form of symlink stored in "OS/2 EAs" on disk (I see them show up on test systems when the Unix Services are loaded) as well as Unix like devices - very strange but potentially could be mapped into something that made sense to Linux.