linux-kernel - Re: [PATCH 1/5] jbd: strictly check for write errors on data buffers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 4 Jun 2008 11:19:11 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Jan Kara <jack@...e.cz>
Cc:	Hidehiro Kawai <hidehiro.kawai.ez@...achi.com>, sct@...hat.com,
	adilger@....com, linux-kernel@...r.kernel.org,
	linux-ext4@...r.kernel.org, jbacik@...hat.com, cmm@...ibm.com,
	tytso@....edu, yumiko.sugita.yf@...achi.com,
	satoshi.oshima.fk@...achi.com
Subject: Re: [PATCH 1/5] jbd: strictly check for write errors on data
 buffers

On Wed, 4 Jun 2008 12:19:25 +0200 Jan Kara <jack@...e.cz> wrote:

> On Tue 03-06-08 15:30:50, Andrew Morton wrote:
> > On Mon, 02 Jun 2008 19:43:57 +0900
> > Hidehiro Kawai <hidehiro.kawai.ez@...achi.com> wrote:
> > 
> > > 
> > > In ordered mode, we should abort journaling when an I/O error has
> > > occurred on a file data buffer in the committing transaction.
> > 
> > Why should we do that?
>   I see two reasons:
> 1) If fs below us is returning IO errors, we don't really know how severe
> it is so it's safest to stop accepting writes. Also user notices the
> problem early this way. I agree that with the growing size of disks and
> thus probability of seeing IO error, we should probably think of something
> cleverer than this but aborting seems better than just doing nothing.
> 
> 2) If the IO error is just transient (i.e., link to NAS is disconnected for
> a while), we would silently break ordering mode guarantees (user could be
> able to see old / uninitialized data).
> 

Does any other filesystem driver turn the fs read-only on the first
write-IO-error?

It seems like a big policy change to me.  For a lot of applications
it's effectively a complete outage and people might get a bit upset if
this happens on the first blip from their NAS.

<waves vigorously at linux-ext4 people>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/