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From: NeilBrown <neilb@suse.de>
To: Phillip Susi <psusi@ubuntu.com>
Cc: Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: Intel fakeraid working?
Date: Tue, 10 Apr 2012 09:43:30 +1000	[thread overview]
Message-ID: <20120410094330.00fb2477@notabene.brown> (raw)
In-Reply-To: <4F7E426F.5000604@ubuntu.com>

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On Thu, 05 Apr 2012 21:10:07 -0400 Phillip Susi <psusi@ubuntu.com> wrote:

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> On 04/05/2012 07:24 PM, NeilBrown wrote:
> > Something wrote to the md device despite it being marked 'read-only'.
> > Some filesystems do that to replay their journal.  totally inexcusable
> > behaviour, but what can we do....
> 
> I agree... read-only means read ONLY.
> 
> > I'm surprised that would happen during installation though.
> > But certainly the array is marked read-only, and certainly something is
> > writing to it, and that is the real bug.
> 
> If the block device is flagged as read only, then shouldn't it reject write attempts even if the fs or userspace issue them?
>

It will reject writes from user-space, and it will reject attempts to mount a
filesystem unless the filesystem is mounted "read-only".
But if a read-only mounted filesystem decides to write anyway (XFS, ext3,
ext4...) then the block layer doesn't stop it.

NeilBrown

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  reply	other threads:[~2012-04-09 23:43 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-05  0:56 Intel fakeraid working? Phillip Susi
2012-04-05  1:13 ` NeilBrown
2012-04-05 18:20   ` Phillip Susi
2012-04-05 23:25     ` NeilBrown
2012-04-06 10:36     ` Jan Ceuleers
2012-04-05 18:23   ` Phillip Susi
2012-04-05 23:24     ` NeilBrown
2012-04-06  1:10       ` Phillip Susi
2012-04-09 23:43         ` NeilBrown [this message]
2012-04-10 13:14           ` Phillip Susi
2012-04-23  2:25             ` NeilBrown
2012-04-23  4:06               ` Phillip Susi

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