From: Namjae Jeon Subject: Re: [PATCH, RFC] Ext4: Mount partition as read only if during orphan cleanup truncate fails to obtain journal handle. Date: Fri, 26 Oct 2012 20:41:19 +0900 Message-ID: References: <1351075240-2725-1-git-send-email-ashish.sangwan2@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: tytso@mit.edu, linux-ext4@vger.kernel.org, Ashish Sangwan , =?UTF-8?B?THVrw6HFoSBDemVybmVy?= , Eric Sandeen , "linux-kernel@vger.kernel.org" To: Ashish Sangwan Return-path: Received: from mail-wi0-f172.google.com ([209.85.212.172]:49601 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932294Ab2JZLlV (ORCPT ); Fri, 26 Oct 2012 07:41:21 -0400 In-Reply-To: <1351075240-2725-1-git-send-email-ashish.sangwan2@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Add Cc in mail loop. Thanks. 2012/10/24, Ashish Sangwan : > During orphan cleanup while doing truncate, if we fail to obtain journal > handle, the inode for which truncate was called would not be removed from > both the on-disk and in-memory orphan lists as the call to ext4_orphan_del > would not be executed. > > This would have following consequences: > a) As the inode is not removed from the on-disk list, truncate would be > called again for the same inode. Each call would add the inode to the > in-memory list. This operation would continue endlessly or until truncate > is succeed. > > b) If somehow, after some iterations, truncate is succeed, ext4_orphan_del > will only remove the inode from in-memory list just 1 time. This will > trigger > j_assert during put super. > > This patch handles both the problems. If truncate fails, first in-memory > list is cleared and than the partition is mounted as read only. > Failure to obtain journal handle during mount may suggest that journal > device is corrupted. > > Signed-off-by: Ashish Sangwan > Signed-off-by: Namjae Jeon > --- > fs/ext4/super.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 4e2aacb..859eccb 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -2201,7 +2201,21 @@ static void ext4_orphan_cleanup(struct super_block > *sb, > jbd_debug(2, "truncating inode %lu to %lld bytes\n", > inode->i_ino, inode->i_size); > ext4_truncate(inode); > - nr_truncates++; > + if (list_empty(&EXT4_I(inode)->i_orphan)) { > + nr_truncates++; > + } else { > + /* Remove inode from in-memory orphan list */ > + list_del_init(&EXT4_I(inode)->i_orphan); > + ext4_msg(sb, KERN_ERR, "Truncate failed for " > + "orphan inode = %lu. Running e2fsck" > + " is recommended", inode->i_ino); > + if (!(s_flags & MS_RDONLY)) { > + ext4_msg(sb, KERN_INFO, "FS would be" > + " mounted as readonly"); > + s_flags |= MS_RDONLY; > + } > + break; > + } > } else { > ext4_msg(sb, KERN_DEBUG, > "%s: deleting unreferenced inode %lu", > -- > 1.7.11.4 > >