From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030213Ab2KUVPN (ORCPT ); Wed, 21 Nov 2012 16:15:13 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:36550 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964878Ab2KUVPL (ORCPT ); Wed, 21 Nov 2012 16:15:11 -0500 Date: Wed, 21 Nov 2012 13:13:19 -0800 From: "Darrick J. Wong" To: Jan Kara Cc: axboe@kernel.dk, lucho@ionkov.net, ericvh@gmail.com, tytso@mit.edu, rminnich@sandia.gov, viro@zeniv.linux.org.uk, martin.petersen@oracle.com, neilb@suse.de, david@fromorbit.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, adilger.kernel@dilger.ca, bharrosh@panasas.com, jlayton@samba.org, v9fs-developer@lists.sourceforge.net, linux-ext4@vger.kernel.org Subject: Re: [PATCH 4/4] ext3: Warn if mounting rw on a disk requiring stable page writes Message-ID: <20121121211319.GA32202@blackbox.djwong.org> References: <20121121020027.10225.43206.stgit@blackbox.djwong.org> <20121121020056.10225.15220.stgit@blackbox.djwong.org> <20121121021543.GI10507@quack.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121121021543.GI10507@quack.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 21, 2012 at 03:15:43AM +0100, Jan Kara wrote: > On Tue 20-11-12 18:00:56, Darrick J. Wong wrote: > > ext3 doesn't properly isolate pages from changes during writeback. Since the > > recommended fix is to use ext4, for now we'll just print a warning if the user > > tries to mount in write mode. > > > > Signed-off-by: Darrick J. Wong > > --- > > fs/ext3/super.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/fs/ext3/super.c b/fs/ext3/super.c > > index 5366393..5b3725d 100644 > > --- a/fs/ext3/super.c > > +++ b/fs/ext3/super.c > > @@ -1325,6 +1325,14 @@ static int ext3_setup_super(struct super_block *sb, struct ext3_super_block *es, > > "forcing read-only mode"); > > res = MS_RDONLY; > > } > > + if (!read_only && > > + queue_requires_stable_pages(bdev_get_queue(sb->s_bdev))) { > > + ext3_msg(sb, KERN_ERR, > > + "error: ext3 cannot safely write data to a disk " > > + "requiring stable pages writes; forcing read-only " > > + "mode. Upgrading to ext4 is recommended."); > > + res = MS_RDONLY; > > + } > > if (read_only) > > return res; > > if (!(sbi->s_mount_state & EXT3_VALID_FS)) > Why this? ext3 should be fixed by your change to > filemap_page_mkwrite()... Or does testing show otherwise? Yes, it's still broken even with this new set of changes. Now that I think about it a little more, I recall that writeback mode was actually fine, so this is a little harsh. Hm... looking at the ordered code a little more, it looks like ext3_ordered_write_end is calling journal_dirty_data_fn, which (I guess?) tries to write mapped buffers back through the journal? Taking it out seems to fix ordered mode, though I have a suspicion that it might very well break ordered mode too. --D > > Honza > -- > Jan Kara > SUSE Labs, CR > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html