From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264944AbTLFDqx (ORCPT ); Fri, 5 Dec 2003 22:46:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264945AbTLFDqx (ORCPT ); Fri, 5 Dec 2003 22:46:53 -0500 Received: from ns3.mountaincable.net ([24.215.0.13]:27544 "EHLO ns3.mountaincable.net") by vger.kernel.org with ESMTP id S264944AbTLFDqw (ORCPT ); Fri, 5 Dec 2003 22:46:52 -0500 Subject: shmem_file_setup creating SYSV00000000 files in (ext3) root filesystem From: desrt To: linux-kernel@vger.kernel.org Content-Type: text/plain Message-Id: <1070682344.17941.6.camel@peloton.desrt.ca> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Fri, 05 Dec 2003 22:45:44 -0500 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org kernel version is 2.4.23. the problem is caused by the fact that the checks that shmem_file_setup does to determine the location of the mountpoint of tmpfs fail to take into account the effect of pivot_root. that is: if i mount a tmpfs as /, then mount a ext3 filesystem and pivot_root into it with put_old as, say, /var/tmp, then shmem_file_setup will still think that the tmpfs is mounted at / (and as a result creates shared memory files on the root filesystem instead of on /var/tmp as it ought to) i'm not actually sure what the code in mm/shmem.c:shmem_file_setup() does, but i assume the problem is this line: root = shm_mnt->mnt_root; and somehow as a result, this happens: peloton:/proc# grep deleted */maps 17923/maps:4201a000-4207a000 rw-s 00000000 00:04 21233690 /SYSV00000000 (deleted) 17923/maps:424dd000-4253d000 rw-s 00000000 00:04 21266460 /SYSV00000000 (deleted) 17926/maps:4201a000-4207a000 rw-s 00000000 00:04 21233690 /SYSV00000000 (deleted) 17926/maps:424dd000-4253d000 rw-s 00000000 00:04 21266460 /SYSV00000000 (deleted) 17927/maps:4201a000-4207a000 rw-s 00000000 00:04 21233690 /SYSV00000000 (deleted) [many many many lines follow] if you have any advice or can confirm to me that this is actually a bug in the kernel, please reply. i'm not on the list. thanks, ryan.