Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755348AbaGWGGy (ORCPT ); Wed, 23 Jul 2014 02:06:54 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:34901 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752821AbaGWGGx (ORCPT ); Wed, 23 Jul 2014 02:06:53 -0400 X-Sasl-enc: cSu7VQ/xHv+pptJDfy7g2S6fFDdcrsFInczT7UX9qeyi 1406095611 Message-ID: <1406095603.2509.11.camel@perseus.fritz.box> Subject: Re: [PATCH v4] fs: umount on symlink leaks mnt count From: Ian Kent To: Vasily Averin Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Weinberger Date: Wed, 23 Jul 2014 14:06:43 +0800 In-Reply-To: <53CCCF9F.6090301@parallels.com> References: <53CCCF9F.6090301@parallels.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-2.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-07-21 at 12:30 +0400, Vasily Averin wrote: > 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 Acked-by: Ian Kent I was working on this too. I prefer this patch over my own. Haven't tested it yet but it is very similar to the patch I was working with which had seen some basic testing. > --- > 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: -- 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/