From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Delays on "first" access to a NFS mount Date: Thu, 8 Mar 2007 09:37:18 +1100 Message-ID: <17903.16030.26119.464793@notabene.brown> References: <20070307112347.6a40faff.simon.peter@gmx.de> <20070307160633.77afb618.simon.peter@gmx.de> <20070307154240.GB26553@fieldses.org> <20070307194418.97fee0ec.simon.peter@gmx.de> <20070307205016.GI26553@fieldses.org> <20070307211729.GO26553@fieldses.org> <20070307215406.GR26553@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net, "Talpey, Thomas" , Simon Peter To: "J. Bruce Fields" Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1HP4lB-0006lr-Jx for nfs@lists.sourceforge.net; Wed, 07 Mar 2007 14:37:25 -0800 Received: from mx2.suse.de ([195.135.220.15]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1HP4lD-0002Wd-6B for nfs@lists.sourceforge.net; Wed, 07 Mar 2007 14:37:27 -0800 In-Reply-To: message from J. Bruce Fields on Wednesday March 7 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net On Wednesday March 7, bfields@fieldses.org wrote: > > Well, non-head-hurty ideas always welcomed. I've got two export-related > problems to fix: > > - Our current NFSv4 pseudofs fsid=0 hack is a pain to administer > and results in inconsistent paths across different NFS > versions. You've got to put that v4 pseudo root somewhere... It just needs cleverness in nfs-utils to auto-bind-mount things into the pseudoroot... but I guess people cannot magically unmount things then. How about this. We add an export option "follow-symlinks" so that when nfsd is asked to stat a symlink it does a 'stat' instead of an 'lstat' (effectively). Then we get mountd to make a tmpfs in /var/lib/nfs/pseudoroot which contains directories and symlinks to the various export points names in etab. This tmpfs is exported as fsid=0,follow-symlinks. Problem solved? Ofcourse if different clients get to see different exports, then we might need multiple tmpfs's in /var/lib/nfs/pseudoroot/$CLIENT/ .... > > - The trick of using the pseudoflavor as a client name (so doing > > /export gss/krb5(rw) > > instead of > > /export *(sec=krb5,rw) > > ), is inconsistent with what other os's do, and makes it > impossible to specify restrictions based both on flavor and on > ip network/dns name/netgroup. Yeeesssss. If you are using crypto-security, then the source-ip-address (which is a terribly weak form of security) should be irrelevant. But I think you've convinced me that some people have valid cases for the combined tested. Grumble Grumble ;-) > > While I'm at it Trond and Christoph and others seem to be asking whether > we can't make some more fundamental changes, such as: > > - Maintaining a static in-kernel exports table instead of > loading it on demand from mountd, and > Don't like that idea at all. Demand-loading is a good thing. > - divorcing the exports namespace completely from any local > process namespace, to the extent that you could even just say > "I want to export /dev/sda7 as /usr/local/bin" without first > mounting /dev/sda7 someplace. I like that even less. Much much less. Way way way less. Yuck. Having a private name-space for nfsd and co might be OK, but that is the closest I could come to the above suggestion, and even then I'm not convinced. I think private name spaces are a very powerful tool that should be used very very carefully. There is plenty of room for confusion of the poor sysadmin if you start doing too much with private name spaces. If you built a system where every daemon has a private namespace, then having one for nfsd would be ok, but it really should be a system wide approach to management, not an approach only used by nfsd. NeilBrown ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs