From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-ext4 <linux-ext4@vger.kernel.org>, eric.saint.etienne@oracle.com
Subject: Re: [PATCH] tune2fs: prohibit toggling uninit_bg on live filesystems
Date: Thu, 21 Nov 2019 13:22:40 -0500 [thread overview]
Message-ID: <20191121182240.GJ4262@mit.edu> (raw)
In-Reply-To: <20191120193255.GF6213@magnolia>
On Wed, Nov 20, 2019 at 11:32:55AM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> An internal customer followed an erroneous AskUbuntu article[1] to try to
> change the UUID of a live ext4 filesystem. The article claims that you
> can work around tune2fs' "cannot change UUID on live fs" error by
> disabling uninit_bg, changing the UUID, and re-enabling the feature.
>
> This led to metadata corruption because tune2fs' journal descriptor
> rewrite races with regular filesystem writes. Therefore, prevent
> administrators from turning on or off uninit_bg on a mounted fs.
>
> [1] https://askubuntu.com/questions/132079/how-do-i-change-uuid-of-a-disk-to-whatever-i-want/195839#459097
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Thanks, applied.
- Ted
prev parent reply other threads:[~2019-11-21 18:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-20 19:32 [PATCH] tune2fs: prohibit toggling uninit_bg on live filesystems Darrick J. Wong
2019-11-21 18:22 ` Theodore Y. Ts'o [this message]
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