From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266679AbUIVTJv (ORCPT ); Wed, 22 Sep 2004 15:09:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266687AbUIVTJv (ORCPT ); Wed, 22 Sep 2004 15:09:51 -0400 Received: from open.hands.com ([195.224.53.39]:8879 "EHLO open.hands.com") by vger.kernel.org with ESMTP id S266679AbUIVTIY (ORCPT ); Wed, 22 Sep 2004 15:08:24 -0400 Date: Wed, 22 Sep 2004 20:19:31 +0100 From: Luke Kenneth Casson Leighton To: linux-kernel@vger.kernel.org Subject: hur hur. fusexmp (userspace fs) + autofs + mount --rbind equals BLURP Message-ID: <20040922191931.GD7308@lkcl.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.5.1+cvs20040105i X-hands-com-MailScanner: Found to be clean X-hands-com-MailScanner-SpamScore: s X-MailScanner-From: lkcl@lkcl.net Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org anybody scared of ugly usage of linux kernel modules should look away, _right_ now :) ... that having been said, this is quite a problem for mount --rbind. repro setup: 1) install fuse. 2) install autofs. 3) write an /etc/autofs.media with a mountpoint /media/floppy 4) mkdir /mnt/test and run fusexmp /mnt/test & 5) mkdir /home/yourhome/media and mount --rbind /media /home/yourhome/media 6) attempt to access /mnt/test/home/yourhome/media/floppy ... and watch the little bits of kernel segfaults go _flying_ by... this is with 2.6.8[.1-selinux1]. some clues as to there-might-be-a-problem-with-rbind are that the problem does _not_ occur if you access /home/yourhome/media/floppy, and a second clue is that if there are any subdirectories in /media prior to running autofs, with a bit of dickering about with the order of the above repro setup it's possible to _see_ those subdirectories _even_ though you've done a mount --rbind. i think i saw this occur when i swapped stages 4) and 5) above. l. -- -- Truth, honesty and respect are rare commodities that all spring from the same well: Love. If you love yourself and everyone and everything around you, funnily and coincidentally enough, life gets a lot better. -- lkcl.net
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