From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Waychison Subject: [PATCH 4/28] VFS: Stat shouldn't stop expire Date: Mon, 25 Oct 2004 10:40:30 -0400 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <1098715230634@sun.com> References: <10987152003432@sun.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: raven@themaw.net Return-path: In-Reply-To: <10987152003432@sun.com> To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org This patch fixes the problem where if you have a mountpoint that is going to expire, it fails to expire before somebody keeps stat(2)ing the root of it's filesystem. For example, consider the case where a user has his home directory automounted on /home/mikew. Some other user can keep the filesystem mounted forever by simply calling ls(1) in /home, because the stat action resets the marker on each call. Signed-off-by: Mike Waychison --- namei.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletion(-) Index: linux-2.6.9-quilt/fs/namei.c =================================================================== --- linux-2.6.9-quilt.orig/fs/namei.c 2004-08-14 01:36:45.000000000 -0400 +++ linux-2.6.9-quilt/fs/namei.c 2004-10-22 17:17:34.762179488 -0400 @@ -275,7 +275,16 @@ int deny_write_access(struct file * file void path_release(struct nameidata *nd) { dput(nd->dentry); - mntput(nd->mnt); + /* + * In order to ensure that access to an automounted filesystems' + * root does not reset it's expire counter, we check to see if the path + * being released here is a mountpoint itself. If it is, then we call + * _mntput which leaves the expire counter alone. + */ + if (nd->mnt && nd->mnt->mnt_root == nd->dentry) + _mntput(nd->mnt); + else + mntput(nd->mnt); } /*