From: Theodore Ts'o Subject: Re: [4.7-rc6 ext3 BUG] kernel BUG at fs/ext4/xattr.c:1331 Date: Sun, 31 Jul 2016 23:09:09 -0400 Message-ID: <20160801030909.GD12853@thunk.org> References: <20160718022356.GC1922@dastard> <20160718030256.GD1922@dastard> <83e3076d-4f84-705d-5259-b3ac1aaf90b7@redhat.com> <20160718052447.GE1922@dastard> <20160728135432.GA19398@quack2.suse.cz> <20160729002112.GX16044@dastard> <20160729064210.GA3611@quack2.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dave Chinner , Eric Sandeen , linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from imap.thunk.org ([74.207.234.97]:33088 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751377AbcHADJ4 (ORCPT ); Sun, 31 Jul 2016 23:09:56 -0400 Content-Disposition: inline In-Reply-To: <20160729064210.GA3611@quack2.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Jul 29, 2016 at 08:42:10AM +0200, Jan Kara wrote: > > I have written some fixes, working on testing them... So hopefully I can > submit them later today or next week. How complicated are the fixes? This should work as a temporary workaround and it going to be very simple to backport. - Ted commit e92d5b1cf6af642bc5018562e58044fd771f82bf Author: Theodore Ts'o Date: Sun Jul 31 23:08:28 2016 -0400 ext4: suppress inode growth for file systems w/o project quota We have not added a new "extra" inode field in a very long time, and the code to deal with moving the extended attributes down to make room for the extra inode fields has bitrotted and can cause kernel BUGS. Very few people will likely use project quotas (and those that do will likely be creating a new file system from scratch) so as a temporary pallative until we are sure the inode expansion code is all sane, let's not try to expand the inode "extra" fields if the project feature has not been enabled. Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Theodore Ts'o diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c13a4e4..e2622ba 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3968,6 +3968,17 @@ no_journal: if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) { sbi->s_want_extra_isize = sizeof(struct ext4_inode) - EXT4_GOOD_OLD_INODE_SIZE; + /* + * This is a temporary hack; we have not added a new + * "extra" inode field in a long time, and the code to + * expand the inode structure has bitrotted and can + * cause kernel BUG's. If the file system does not + * have the project feature, let's not try to expand + * the inode's extra size as a temporary pallitive + * until we can fix up the inode expansion code. + */ + if (!ext4_has_feature_project(sb)) + sbi->s_want_extra_isize -= sizeof(__le32); if (ext4_has_feature_extra_isize(sb)) { if (sbi->s_want_extra_isize < le16_to_cpu(es->s_want_extra_isize))