From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:33594 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751903Ab2KFNgM (ORCPT ); Tue, 6 Nov 2012 08:36:12 -0500 Date: Tue, 6 Nov 2012 08:36:05 -0500 From: "J. Bruce Fields" To: Christoph Hellwig Cc: Stanislav Kinsbursky , "Trond.Myklebust@netapp.com" , "linux-nfs@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devel@openvz.org" , "Eric W. Biederman" Subject: Re: [PATCH v3] SUNRPC: set desired file system root before connecting local transports Message-ID: <20121106133605.GD6718@fieldses.org> References: <20121008105437.18668.99905.stgit@localhost.localdomain> <20121009193506.GA19680@fieldses.org> <5098E31A.5080801@parallels.com> <20121106120642.GA6718@fieldses.org> <20121106124035.GA20522@infradead.org> <20121106130705.GC6718@fieldses.org> <20121106131018.GA12211@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20121106131018.GA12211@infradead.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Nov 06, 2012 at 08:10:18AM -0500, Christoph Hellwig wrote: > On Tue, Nov 06, 2012 at 08:07:06AM -0500, J. Bruce Fields wrote: > > So you're worried that a bug in the nfs code could modify the root and > > then not restore it? > > At least the link you pointed to earlier never sets it back. This? http://thread.gmane.org/gmane.linux.kernel/1259986/focus=47687 + get_fs_root(current->fs, &root); + set_fs_root(current->fs, &transport->root); + status = xs_local_finish_connecting(xprt, sock); + + set_fs_root(current->fs, &root); + path_put(&root); > Instead > of messing with it I'd rather have the sunrpc code use vfs_path_lookup > and not care about current->fs->root at all. The annoyance is that the lookup happens somewhere lower down in the networking code (net/unix/af_unix.c:unix_find_other, I think). So we'd need some new (internal) API. We'd likely be the only user of that new API. --b.