From: "J. Bruce Fields" Subject: Re: [NFS] NFSv2/3 broken exporting/mounting (permission denied) in 2.6.24-rc4 Date: Fri, 7 Dec 2007 15:06:55 -0500 Message-ID: <20071207200655.GD2204__48932.5402807028$1197061718$gmane$org@fieldses.org> References: <20071207025504.GA3070@fieldses.org> <200712072000.lB7K0DZ5013256@agora.fsl.cs.sunysb.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Andrew Morton , linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , nfs@lists.sourceforge.net, "Eric W. Biederman" , Pavel Machek , Herbert Xu , Ingo Molnar , "David S. Miller" , Pavel Emelyanov To: Erez Zadok Return-path: Received: from neil.brown.name ([220.233.11.133]:48085 "EHLO neil.brown.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752506AbXLGVIE (ORCPT ); Fri, 7 Dec 2007 16:08:04 -0500 Received: from brown by neil.brown.name with local (Exim 4.63) (envelope-from ) id 1J0kQT-0007fX-N4 for linux-nfs@vger.kernel.org; Sat, 08 Dec 2007 08:08:01 +1100 In-Reply-To: <200712072000.lB7K0DZ5013256-zop+azHP2WsZjdeEBZXbMidm6ipF23ct@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, Dec 07, 2007 at 03:00:13PM -0500, Erez Zadok wrote: > In message <20071207025504.GA3070@fieldses.org>, "J. Bruce Fields" writes: > > On Thu, Dec 06, 2007 at 09:20:41PM -0500, Erez Zadok wrote: > > > I get a "permission denied" when trying to mount a localhost nfsv2/3 > > > exported volume, on v2.6.24-rc4-124-gf194d13. It works w/ nfsv4 mounting. > > > It worked fine in 2.6.24-rc3. Here's a sequence of ops I tried: > > > > > > # mount -t ext2 /dev/hdb1 /n/lower/b0 > > > # exportfs -o no_root_squash,rw localhost:/n/lower/b0 > > > # mount -t nfs -o nfsvers=3 localhost:/n/lower/b0 /mnt > > > > What do you see if you watch the network traffic in ethereal? > > > > --b. > > Bruce, I'm using nfs-utils-1.0.10-14.fc6 on an FC6 system with all latest > FC6 patches. Using git-bisect I was able to find the patch which broke it: Wow, thanks for your work finding that. > > commit 2b1e300a9dfc3196ccddf6f1d74b91b7af55e416 > Author: Eric W. Biederman > Date: Sun Dec 2 00:33:17 2007 +1100 > > [NETNS]: Fix /proc/net breakage > > Well I clearly goofed when I added the initial network namespace support > for /proc/net. Currently things work but there are odd details visible to > user space, even when we have a single network namespace. > > Since we do not cache proc_dir_entry dentries at the moment we can just > modify ->lookup to return a different directory inode depending on the > network namespace of the process looking at /proc/net, replacing the > current technique of using a magic and fragile follow_link method. > > To accomplish that this patch: > - introduces a shadow_proc method to allow different dentries to > be returned from proc_lookup. > - Removes the old /proc/net follow_link magic > - Fixes a weakness in our not caching of proc generic dentries. > > As shadow_proc uses a task struct to decided which dentry to return we can > go back later and fix the proc generic caching without modifying any code > that uses the shadow_proc method. > > Signed-off-by: Eric W. Biederman > Cc: "Rafael J. Wysocki" > Cc: Pavel Machek > Cc: Pavel Emelyanov > Cc: "David S. Miller" > Cc: Ingo Molnar > Signed-off-by: Andrew Morton > Signed-off-by: Herbert Xu > > With the above patch, rpc.mountd is unable to open /proc/fs/nfsd/filehandle. > Strace shows: > > open("/proc/fs/nfsd/filehandle", O_RDWR|O_LARGEFILE) = -1 ENOENT (No such file or directory) > > Without the above patch, /proc/fs/nfsd is populated with a number of files, > including "filehandle". Those files are actually in a separate filesystem (of type "nfsd") which is supposed to be mounted on /proc/fs/nfsd/. So that mount must have failed in the bad case? It's not immediately obvious to me what this patch has to do with that. Hm. --b. ------------------------------------------------------------------------- SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs _______________________________________________ Please note that nfs@lists.sourceforge.net is being discontinued. Please subscribe to linux-nfs@vger.kernel.org instead. http://vger.kernel.org/vger-lists.html#linux-nfs