linux-ext4 - Re: 2.6.35-r5 ext3 corruptions

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]

Message-ID: <4C46FC67.4000900@redhat.com>
Date:	Wed, 21 Jul 2010 08:55:51 -0500
From:	Eric Sandeen <sandeen@...hat.com>
To:	Dave Chinner <david@...morbit.com>
CC:	linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jan Kara <jack@...e.cz>
Subject: Re: 2.6.35-r5 ext3 corruptions

Dave Chinner wrote:

> Ok, so now I know *why* that one filesystem got busted - I built a
> kernel without CONFIG_EXT3_DEFAULTS_TO_ORDERED set and it got a
> forced reboot (echo b > proc/sysrq-trigger). That'll teach me for
> trying to reproduce bugs Andrew is tripping over with his config
> files.
> 
> Quite frankly, data=writeback mode for ext3 is a dangerous,
> dangerous configuration to run by default. IMO, it shouldn't be the
> default. Patch below.

I agree, though I might just remove the config option altogether,
it just obfuscates what's going on, IMHO.

Still, as far as it goes, you can add:

Acked-by: Eric Sandeen <sandeen@...hat.com>

to the patch.

-Eric

> ext3: default to ordered mode
> 
> From: Dave Chinner <dchinner@...hat.com>
> 
> data=writeback mode is dangerous and is leads to filesystem
> corruption, data loss and stale data exposure when systems crash. It
> should not be the default, especially when all major distros ensure
> their ext3 filesystems default to ordered mode. Change the default
> mode to the safer data=ordered mode, because we should be caring
> far more about avoiding corruption than performance.
> 
> Signed-off-by: Dave Chinner <dchinner@...hat.com>
> ---
>  fs/ext3/Kconfig |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ext3/Kconfig b/fs/ext3/Kconfig
> index 522b154..e8c6ba0 100644
> --- a/fs/ext3/Kconfig
> +++ b/fs/ext3/Kconfig
> @@ -31,6 +31,7 @@ config EXT3_FS
>  config EXT3_DEFAULTS_TO_ORDERED
>  	bool "Default to 'data=ordered' in ext3"
>  	depends on EXT3_FS
> +	default y
>  	help
>  	  The journal mode options for ext3 have different tradeoffs
>  	  between when data is guaranteed to be on disk and

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html