Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-yx0-f174.google.com ([209.85.213.174]:36593 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757422Ab2EKJUZ (ORCPT ); Fri, 11 May 2012 05:20:25 -0400 Date: Fri, 11 May 2012 04:20:20 -0500 From: Jonathan Nieder To: stable@vger.kernel.org Cc: Rik Theys , Trond Myklebust , linux-nfs@vger.kernel.org, David Flyn , Jeff Layton , 659111@bugs.debian.org Subject: [PATCH 3.0.y, 3.2.y] NFSv4: Revalidate uid/gid after open Message-ID: <20120511092020.GD5733@burratino> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: This is a shorter (and more appropriate for stable kernels) analog to the following upstream commit: commit 6926afd1925a54a13684ebe05987868890665e2b Author: Trond Myklebust Date: Sat Jan 7 13:22:46 2012 -0500 NFSv4: Save the owner/group name string when doing open ...so that we can do the uid/gid mapping outside the asynchronous RPC context. This fixes a bug in the current NFSv4 atomic open code where the client isn't able to determine what the true uid/gid fields of the file are, (because the asynchronous nature of the OPEN call denies it the ability to do an upcall) and so fills them with default values, marking the inode as needing revalidation. Unfortunately, in some cases, the VFS will do some additional sanity checks on the file, and may override the server's decision to allow the open because it sees the wrong owner/group fields. Signed-off-by: Trond Myklebust Without this patch, logging into two different machines with home directories mounted over NFS4 and then running "vim" and typing ":q" in each reliably produces the following error on the second machine: E137: Viminfo file is not writable: /users/system/rtheys/.viminfo This regression was introduced by 80e52aced138 ("NFSv4: Don't do idmapper upcalls for asynchronous RPC calls", merged during the 2.6.32 cycle) --- after the OPEN call, .viminfo has the default values for st_uid and st_gid (0xfffffffe) cached because we do not want to let rpciod wait for an idmapper upcall to fill them in. The fix used in mainline is to save the owner and group as strings and perform the upcall in _nfs4_proc_open outside the rpciod context, which takes about 600 lines. For stable, we can do something similar with a one-liner: make open check for the stale fields and make a (synchronous) GETATTR call to fill them when needed. Trond dictated the patch, I typed it in, and Rik tested it. Addresses http://bugs.debian.org/659111 and https://bugzilla.redhat.com/789298 Reported-by: Rik Theys Explained-by: David Flyn Signed-off-by: Jonathan Nieder Tested-by: Rik Theys --- Hi Ben and Greg, Please consider this patch for inclusion in 3.0.y and 3.2.y kernels. 3.3.y doesn't need it since 6926afd1925a was merged during the 3.3 merge window. Rik tested it against a 3.2.16-based kernel and found it to work. [1] has details. Thanks, Jonathan [1] http://bugs.debian.org/659111 fs/nfs/nfs4proc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 3d6730213f9d..30f6548f2b99 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -1771,6 +1771,7 @@ static int _nfs4_do_open(struct inode *dir, struct path *path, fmode_t fmode, in nfs_setattr_update_inode(state->inode, sattr); nfs_post_op_update_inode(state->inode, opendata->o_res.f_attr); } + nfs_revalidate_inode(server, state->inode); nfs4_opendata_put(opendata); nfs4_put_state_owner(sp); *res = state; -- 1.7.10.1