Re: [57/71] block: rescan partitions on invalidated devices on-ENOMEDIA too

From: Greg KH
Date: Thu May 19 2011 - 14:19:13 EST


On Thu, May 19, 2011 at 08:12:44PM +0200, Tejun Heo wrote:
> Hello, Greg.
>
> On Thu, May 19, 2011 at 8:05 PM, Greg KH <gregkh@xxxxxxx> wrote:
> >
> > 2.6.38-stable review patch.  If anyone has any objections, please let us know.
> >
> > ------------------
> >
> > From: Tejun Heo <tj@xxxxxxxxxx>
> >
> > commit 02e352287a40bd456eb78df705bf888bc3161d3f upstream.
> >
> > __blkdev_get() doesn't rescan partitions if disk->fops->open() fails,
> > which leads to ghost partition devices lingering after medimum removal
> > is known to both the kernel and userland.  The behavior also creates a
> > subtle inconsistency where O_NONBLOCK open, which doesn't fail even if
> > there's no medium, clears the ghots partitions, which is exploited to
> > work around the problem from userland.
> >
> > Fix it by updating __blkdev_get() to issue partition rescan after
> > -ENOMEDIA too.
> >
> > This was reported in the following bz.
> >
> >  https://bugzilla.kernel.org/show_bug.cgi?id=13029
> >
> > Stable: 2.6.38
> >
>
> Can you please hold this for a while? It causes an extra warning
> message to be printed during device detection. It isn't harmful but
> still. I'll soon send a patch to resolve the issue and it would be
> better for them to go together.

Sure, I've dropped this one for now. Let me know when I should add it
back to the next round of stable releases.

thanks,

greg k-h
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