From: Eric Sandeen <sandeen@redhat.com>
Subject: Re: [PATCH 1/4] jbd: abort when failed to log metadata buffers
Date: Thu, 11 Sep 2008 12:41:59 -0500
Message-ID: <48C95867.5080707@redhat.com>
References: <488876D3.80004@hitachi.com> <48887776.4080504@hitachi.com>
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Cc: akpm@linux-foundation.org, sct@redhat.com,
	linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org,
	jack@suse.cz, jbacik@redhat.com, cmm@us.ibm.com, tytso@mit.edu,
	adilger@clusterfs.com, snitzer@gmail.com, tglx@linutronix.de,
	yumiko.sugita.yf@hitachi.com, satoshi.oshima.fk@hitachi.com
To: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
In-Reply-To: <48887776.4080504@hitachi.com>
Sender: linux-ext4-owner@vger.kernel.org

Hidehiro Kawai wrote:
> If we failed to write metadata buffers to the journal space and
> succeeded to write the commit record, stale data can be written
> back to the filesystem as metadata in the recovery phase.
> 
> To avoid this, when we failed to write out metadata buffers,
> abort the journal before writing the commit record.
> 
> Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
> Acked-by: Jan Kara <jack@suse.cz>
> ---
>  fs/jbd/commit.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> Index: linux-2.6.26-rc8-mm1/fs/jbd/commit.c
> ===================================================================
> --- linux-2.6.26-rc8-mm1.orig/fs/jbd/commit.c
> +++ linux-2.6.26-rc8-mm1/fs/jbd/commit.c
> @@ -762,6 +762,9 @@ wait_for_iobuf:
>  		/* AKPM: bforget here */
>  	}
>  
> +	if (err)
> +		journal_abort(journal, err);
> +
>  	jbd_debug(3, "JBD: commit phase 6\n");
>  
>  	if (journal_write_commit_record(journal, commit_transaction))

A little late for me to chime in, but why is this a journal_abort() when
journal aborts before and after this call __journal_abort_hard()?

I'm just not sure what's different about this one condition that we wish
to update the error and the superblock here?

Thanks,
-Eric