From: Erez Zadok Subject: Re: [NFS] NFSv2/3 broken exporting/mounting (permission denied) in 2.6.24-rc4 Date: Fri, 7 Dec 2007 15:00:13 -0500 Message-ID: <200712072000.lB7K0DZ5013256__37008.3231748596$1197061739$gmane$org@agora.fsl.cs.sunysb.edu> References: <20071207025504.GA3070@fieldses.org> 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 , Erez Zadok , "David S. Miller" , Pavel Emelyanov To: "J. Bruce Fields" Return-path: Received: from neil.brown.name ([220.233.11.133]:48086 "EHLO neil.brown.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752670AbXLGVIb (ORCPT ); Fri, 7 Dec 2007 16:08:31 -0500 Received: from brown by neil.brown.name with local (Exim 4.63) (envelope-from ) id 1J0kQs-0007fm-Ms for linux-nfs@vger.kernel.org; Sat, 08 Dec 2007 08:08:26 +1100 In-reply-to: Your message of "Thu, 06 Dec 2007 21:55:04 EST." <20071207025504.GA3070@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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: 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". Erez. ------------------------------------------------------------------------- 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