From patchwork Mon Nov 3 19:34:17 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 6956 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id 7A209DDEE4 for ; Tue, 4 Nov 2008 06:35:53 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754002AbYKCTfn (ORCPT ); Mon, 3 Nov 2008 14:35:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754000AbYKCTfn (ORCPT ); Mon, 3 Nov 2008 14:35:43 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:35812 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753960AbYKCTfm (ORCPT ); Mon, 3 Nov 2008 14:35:42 -0500 Received: from imap1.linux-foundation.org (imap1.linux-foundation.org [140.211.169.55]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id mA3JYKlV022164 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 3 Nov 2008 11:34:21 -0800 Received: from localhost.localdomain (localhost [127.0.0.1]) by imap1.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with ESMTP id mA3JYJ5c023221; Mon, 3 Nov 2008 11:34:19 -0800 Message-Id: <200811031934.mA3JYJ5c023221@imap1.linux-foundation.org> Subject: + ext3-wait-on-all-pending-commits-in-ext3_sync_fs.patch added to -mm tree To: mm-commits@vger.kernel.org Cc: ajones@riverbed.com, linux-ext4@vger.kernel.org, sandeen@redhat.com, stable@kernel.org From: akpm@linux-foundation.org Date: Mon, 03 Nov 2008 11:34:17 -0800 X-Spam-Status: No, hits=-2.865 required=5 tests=AWL,BAYES_00 X-Spam-Checker-Version: SpamAssassin 3.2.4-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.13 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org The patch titled ext3: wait on all pending commits in ext3_sync_fs has been added to the -mm tree. Its filename is ext3-wait-on-all-pending-commits-in-ext3_sync_fs.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ext3: wait on all pending commits in ext3_sync_fs From: Arthur Jones In ext3_sync_fs, we only wait for a commit to finish if we started it, but there may be one already in progress which will not be synced. In the case of a data=ordered umount with pending long symlinks which are delayed due to a long list of other I/O on the backing block device, this causes the buffer associated with the long symlinks to not be moved to the inode dirty list in the second phase of fsync_super. Then, before they can be dirtied again, kjournald exits, seeing the UMOUNT flag and the dirty pages are never written to the backing block device, causing long symlink corruption and exposing new or previously freed block data to userspace. This can be reproduced with a script created by Eric Sandeen : #!/bin/bash umount /mnt/test2 mount /dev/sdb4 /mnt/test2 rm -f /mnt/test2/* dd if=/dev/zero of=/mnt/test2/bigfile bs=1M count=512 touch /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename ln -s /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename /mnt/test2/link umount /mnt/test2 mount /dev/sdb4 /mnt/test2 ls /mnt/test2/ umount /mnt/test2 To ensure all commits are synced, we flush all journal commits now when sync_fs'ing ext3. Signed-off-by: Arthur Jones Eric Sandeen Cc: Cc: [2.6.everything] Signed-off-by: Andrew Morton --- fs/ext3/super.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff -puN fs/ext3/super.c~ext3-wait-on-all-pending-commits-in-ext3_sync_fs fs/ext3/super.c --- a/fs/ext3/super.c~ext3-wait-on-all-pending-commits-in-ext3_sync_fs +++ a/fs/ext3/super.c @@ -2396,7 +2396,13 @@ static int ext3_sync_fs(struct super_blo if (journal_start_commit(EXT3_SB(sb)->s_journal, &target)) { if (wait) log_wait_commit(EXT3_SB(sb)->s_journal, target); - } + } else if (wait) + /* + * We may have a commit in progress, clear it out + * before we go on... + */ + ext3_force_commit(sb); + return 0; }