Re: [BUG] Linux-2.6.31-rc1-git9 Cannot Recognize Empty DVD Media

[Jens Axboe <jens.axboe@oracle.com>]

On Wed, Jul 08 2009, James Bottomley wrote:
> On Wed, 2009-07-08 at 09:06 -0700, Daniel Walker wrote:
> > On Wed, 2009-07-08 at 09:27 -0500, James Bottomley wrote:
> > > 
> > > You might also try this patch from martin petersen:  it will print out
> > > the actual command that's causing the problems ... that might give a
> > > clue.
> > > 
> > > James
> > 
> > On the bugzilla entry ,
> > 
> > http://bugzilla.kernel.org/show_bug.cgi?id=13727
> > 
> > Thomas Meyer indicated it was (possibly) the following commit,
> > 
> > 018e0446890661504783f92388ecce7138c1566d
> > 
> > I added Jens to the CC ..
> 
> So thats:
> 
> commit 018e0446890661504783f92388ecce7138c1566d
> Author: Jens Axboe <jens.axboe@oracle.com>
> Date:   Fri Jun 26 16:27:10 2009 +0200
> 
>     block: get rid of queue-private command filter
> 
> What this tends to suggest is that the command filter was blocking some
> type of command sent from user space which is causing the problem, and
> now we're letting it through.  Restoring the command filter will work
> around the problem, but the root cause should be finding and fixing
> whatever is issuing the commands in the first place.

There should be no functional change, since the filters were all the
same. Perhaps blk_scsi_ioctl_init() isn't being run, a good start would
be to stick a printk() in there and verify that it's actually being
executed. I've been tricked by __init before.

-- 
Jens Axboe