From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ted Ts'o Subject: Re: [PATCH] vfs: avoid hang caused by attempting to rmdir an invalid file system Date: Tue, 29 May 2012 08:18:38 -0400 Message-ID: <20120529121838.GA16351@thunk.org> References: <1338226422-8845-1-git-send-email-tytso@mit.edu> <20120529082144.GA18792@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, Ext4 Developers List , viro@ZenIV.linux.org.uk, sami.liedes@iki.fi To: Greg KH Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:46203 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753868Ab2E2MSo (ORCPT ); Tue, 29 May 2012 08:18:44 -0400 Content-Disposition: inline In-Reply-To: <20120529082144.GA18792@kroah.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, May 29, 2012 at 05:21:44PM +0900, Greg KH wrote: > On Mon, May 28, 2012 at 01:33:42PM -0400, Theodore Ts'o wrote: > > If we rmdir a directory which is a hard link to '.', we will deadlock > > trying to grab the directory's i_mutex. Check for this condition and > > return EINVAL, which is what we return if the user attempts to rmdir > > "/foo/bar/." > > > > Signed-off-by: "Theodore Ts'o" > > --- > > fs/namei.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > Any reason why you didn't also tag this for the stable kernel releases? Because I was sending it out for comment; I wanted to get Al's opinion how to handle whether we needed to inform the low-level file system about the corruption. I should have added an RFC to the subject line, sorry. Andrea's solution of detecting the corruption is lookup seems like the right answer, so at this point, I'll remove the XXX comment, and add the unlikely() annotation to the if statement, and resubmit with a Cc: stable. - Ted