From: Xiang Wang Subject: Re: RFC PATCH: ext4 no journal corruption with locale-gen Date: Mon, 6 Jul 2009 09:21:25 -0700 Message-ID: References: <6601abe90906171148w1431258fvd0afa105cda9b77b@mail.gmail.com> <20090617234604.GF7867@mit.edu> <6601abe90906220942se70fb70w5481e178f1525dd8@mail.gmail.com> <20090701183130.GA31235@skywalker> <20090706034144.GB31532@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Aneesh Kumar K.V" , Curt Wohlgemuth , ext4 development To: Theodore Tso Return-path: Received: from smtp-out.google.com ([216.239.33.17]:11457 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125AbZGFQV1 convert rfc822-to-8bit (ORCPT ); Mon, 6 Jul 2009 12:21:27 -0400 Received: from spaceape7.eur.corp.google.com (spaceape7.eur.corp.google.com [172.28.16.141]) by smtp-out.google.com with ESMTP id n66GLS31008132 for ; Mon, 6 Jul 2009 17:21:28 +0100 Received: from ewy20 (ewy20.prod.google.com [10.241.103.20]) by spaceape7.eur.corp.google.com with ESMTP id n66GLPIa018887 for ; Mon, 6 Jul 2009 09:21:26 -0700 Received: by ewy20 with SMTP id 20so4696183ewy.3 for ; Mon, 06 Jul 2009 09:21:25 -0700 (PDT) In-Reply-To: <20090706034144.GB31532@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Jul 5, 2009 at 8:41 PM, Theodore Tso wrote: > On Thu, Jul 02, 2009 at 12:01:30AM +0530, Aneesh Kumar K.V wrote: >> >> I looked at the patch in detail and =A0I guess we should instead for= ce >> a data=3Dwriteback mode if the filesystem is created without a journ= al. >> I am not sure what whould be the meaning of data=3Dordered/data=3Djo= urnal >> without a journal. So if we find that file system doesn't have a jou= rnal >> then either we should update the default mount option in the filesys= tem >> to be of data=3Dwriteback. > > Here's a patch which takes your approach to solving the problem. =A0W= hat > do you think? > > I haven't messed with dealing with the data=3D mount options in > fs/ext4/super.c. =A0That's important from a UI point of view, but we > needed to fix ext4_jbd2.h since it was unconditionally returning 0 if > there was no journal for all of the ext4_should_*_data() functions. > > I believe this should DTRT with the -o nobh mount option, but I'd > appreciate another pair of eyes taking a look at this. This patch looks good to us. In the long run, we still think adding the data=3Dnojournal mount optio= n is useful and we are working on this patch. Thanks, Xiang > > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= =A0 =A0 - Ted > > commit 2a73eff8ba80095a871a6b402dfd24bc454e5bdc > Author: Theodore Ts'o > Date: =A0 Sun Jul 5 23:37:13 2009 -0400 > > =A0 =A0ext4: fix no journal corruption with locale-gen > > =A0 =A0If there is no journal, ext4_should_writeback_data() should re= turn > =A0 =A0TRUE. =A0This will fix ext4_set_aops() to set ext4_da_ops in t= he case of > =A0 =A0delayed allocation; otherwise ext4_journaled_aops gets used by > =A0 =A0default, which doesn't handle delayed allocation properly. > > =A0 =A0The advantage of using ext4_should_writeback_data() approach i= s that > =A0 =A0it should handle nobh better as well. > > =A0 =A0Thanks to Curt Wohlgemuth for investigating this problem, and = Aneesh > =A0 =A0Kumar for suggesting this approach. > > =A0 =A0Signed-off-by: "Theodore Ts'o" > > diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h > index be2f426..f800134 100644 > --- a/fs/ext4/ext4_jbd2.h > +++ b/fs/ext4/ext4_jbd2.h > @@ -282,7 +282,7 @@ static inline int ext4_should_order_data(struct i= node *inode) > =A0static inline int ext4_should_writeback_data(struct inode *inode) > =A0{ > =A0 =A0 =A0 =A0if (EXT4_JOURNAL(inode) =3D=3D NULL) > - =A0 =A0 =A0 =A0 =A0 =A0 =A0 return 0; > + =A0 =A0 =A0 =A0 =A0 =A0 =A0 return 1; > =A0 =A0 =A0 =A0if (!S_ISREG(inode->i_mode)) > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return 0; > =A0 =A0 =A0 =A0if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL) > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html