From: Chris Mason <chris.mason@oracle.com>
Subject: Re: [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses
Date: Tue, 10 May 2011 12:24:50 -0400
Message-ID: <1305044672-sup-6072@shiny>
References: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> <20110510125124.GD4402@quack.suse.cz>
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Cc: "Darrick J. Wong" <djwong@us.ibm.com>, Theodore Tso <tytso@mit.edu>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
        Jens Axboe <axboe@kernel.dk>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Jeff Layton <jlayton@redhat.com>, Dave Chinner <david@fromorbit.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Dave Hansen <dave@linux.vnet.ibm.com>,
        Christoph Hellwig <hch@infradead.org>, linux-mm <linux-mm@kvack.org>,
        Joel Becker <jlbec@evilplan.org>,
        linux-scsi <linux-scsi@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-ext4 <linux-ext4@vger.kernel.org>,
        Mingming Cao <mcao@us.ibm.com>
To: Jan Kara <jack@suse.cz>
Return-path: <owner-linux-mm@kvack.org>
In-reply-to: <20110510125124.GD4402@quack.suse.cz>
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List-Id: linux-ext4.vger.kernel.org

Excerpts from Jan Kara's message of 2011-05-10 08:51:24 -0400:
> On Mon 09-05-11 16:03:18, Darrick J. Wong wrote:
> > I am still chasing down what exactly is broken in ext3.  data=3Dwrite=
back mode
> > passes with no failures.  data=3Dordered, however, does not pass; my =
current
> > suspicion is that jbd is calling submit_bh on data buffers but doesn'=
t call
> > page_mkclean to kick the userspace programs off the page before writi=
ng it.
>   Yes, ext3 in data=3Dordered mode writes pages from
> journal_commit_transaction() via submit_bh() without clearing page dirt=
y
> bits thus page_mkclean() is not called for these pages. Frankly, do you
> really want to bother with adding support for ext2 and ext3? People can=
 use
> ext4 as a fs driver when they want to start using blk-integrity support=
.
> Especially ext2 patch looks really painful and just from a quick look I=
 can
> see code e.g. in fs/ext2/namei.c which isn't handled by your patch yet.

I think ext23 are going to be pretty big changes, we're best off just
going with ext4.

-chris

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