From: Phillip Susi <psusi@ubuntu.com>
To: NeilBrown <neilb@suse.de>
Cc: Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: Intel fakeraid working?
Date: Tue, 10 Apr 2012 09:14:58 -0400 [thread overview]
Message-ID: <4F843252.5090109@ubuntu.com> (raw)
In-Reply-To: <20120410094330.00fb2477@notabene.brown>
On 4/9/2012 7:43 PM, NeilBrown wrote:
> 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.
How does that work? How does the block layer know or care what mount
flags are used? My understanding is that setting the block layer
read-only flag with blockdev --setro actually causes the write bios to
be rejected, thus preventing ext[34] from playing back the journal.
Ubuntu has been using this to prevent accidental damage by read-only
mounts since this abhorrent behavior was discovered. I would think that
md should work the same way.
next prev parent reply other threads:[~2012-04-10 13:14 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
2012-04-10 13:14 ` Phillip Susi [this message]
2012-04-23 2:25 ` NeilBrown
2012-04-23 4:06 ` Phillip Susi
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