From: Eric Sandeen Subject: [PATCH] [UPDATED] ext3: refuse ro to rw remount of fs with orphan inodes Date: Thu, 11 Jan 2007 14:28:14 -0600 Message-ID: <45A69DDE.2020208@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([66.187.233.31]:46405 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751371AbXAKU2Y (ORCPT ); Thu, 11 Jan 2007 15:28:24 -0500 To: Linux Kernel Mailing List , ext4 development Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org This is a followup to the patch which skipped orphan inode processing on a filesystem residing on a readonly bdev (think snapshot taken with open, unlinked files). That avoided an oops. Stephen had concerns about what happens if the bdev later goes readwrite, and the filesystem is subsequently mounted remount,rw - if the orphan list isn't processed then, things will be in bad shape. The patch I sent earlier to process the orphan inode list on remount was met with silence and/or slight suspicion (from akpm) so how about this: just to plug the hole on what I think is a pretty rare condition, simply disallow the ro->rw transition if we have unprocessed orphan inodes. Then we get this: [root@magnesium ~]# mount -o remount,rw /mnt/test mount: /mnt/test not mounted already, or bad option [root@magnesium ~]# dmesg | tail -n 1 EXT3-fs: hda7: couldn't remount RDWR because of unprocessed orphan inode list. Please umount/remount instead. Signed-off-by: Eric Sandeen Index: linux-2.6.19/fs/ext3/super.c =================================================================== --- linux-2.6.19.orig/fs/ext3/super.c +++ linux-2.6.19/fs/ext3/super.c @@ -2350,6 +2350,22 @@ static int ext3_remount (struct super_bl err = -EROFS; goto restore_opts; } + + /* + * If we have an unprocessed orphan list hanging + * around from a previously readonly bdev mount, + * require a full umount/remount for now. + */ + if (es->s_last_orphan) { + printk(KERN_WARNING "EXT3-fs: %s: couldn't " + "remount RDWR because of unprocessed " + "orphan inode list. Please " + "umount/remount instead.\n", + sb->s_id); + err = -EINVAL; + goto restore_opts; + } + /* * Mounting a RDONLY partition read-write, so reread * and store the current valid flag. (It may have