Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753691AbaGUIbF (ORCPT ); Mon, 21 Jul 2014 04:31:05 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:19336 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752198AbaGUIbC (ORCPT ); Mon, 21 Jul 2014 04:31:02 -0400 Message-ID: <53CCCF9F.6090301@parallels.com> Date: Mon, 21 Jul 2014 12:30:23 +0400 From: Vasily Averin Organization: Parallels User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Weinberger Subject: [PATCH v4] fs: umount on symlink leaks mnt count References: In-Reply-To: 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 v4: description corrected v3: patch inline Currently umount on symlink blocks following umount: /vz is separate mount # ls /vz/ -al | grep test drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir # umount -l /vz/testlink umount: /vz/testlink: not mounted (expected) # lsof /vz # umount /vz umount: /vz: device is busy. (unexpected) In this case mountpoint_last() gets an extra refcount on path->mnt Signed-off-by: Vasily Averin --- fs/namei.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 985c6f3..9eb787e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2256,9 +2256,10 @@ done: goto out; } path->dentry = dentry; - path->mnt = mntget(nd->path.mnt); + path->mnt = nd->path.mnt; if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) return 1; + mntget(path->mnt); follow_mount(path); error = 0; out: -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/