From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755503Ab2BUSR4 (ORCPT ); Tue, 21 Feb 2012 13:17:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:7585 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753969Ab2BUSRm (ORCPT ); Tue, 21 Feb 2012 13:17:42 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH 52/73] union-mount: Set opaque flag on new directories in unioned file systems [ver #2] To: linux-fsdevel@vger.kernel.org, viro@ZenIV.linux.org.uk, valerie.aurora@gmail.com Cc: linux-kernel@vger.kernel.org, Jan Blunck , Valerie Aurora , David Howells Date: Tue, 21 Feb 2012 18:03:58 +0000 Message-ID: <20120221180358.25235.32044.stgit@warthog.procyon.org.uk> In-Reply-To: <20120221175721.25235.8901.stgit@warthog.procyon.org.uk> References: <20120221175721.25235.8901.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Valerie Aurora If we mkdir() a directory on the top layer of a union, we don't want entries from a matching directory on the lower layer to "show through" suddenly. To prevent this, we set the opaque flag on a directory in a union mount if there is no matching directory on the lower layers. Signed-off-by: Jan Blunck Signed-off-by: Valerie Aurora Signed-off-by: David Howells --- fs/namei.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index f9e0d68..d52377d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2946,8 +2946,17 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) return error; error = dir->i_op->mkdir(dir, dentry, mode); - if (!error) - fsnotify_mkdir(dir, dentry); + if (error) + return error; + + /* XXX racy - crash now and dir isn't opaque */ + if (IS_DIR_UNIONED(dentry->d_parent)) { + dentry->d_inode->i_flags |= S_OPAQUE; + mark_inode_dirty(dentry->d_inode); + } + + fsnotify_mkdir(dir, dentry); + return error; }