Re: Is this a known problem with the SCSI mid layer?

[scameron@beardog.cce.hp.com]

On Fri, Jan 15, 2010 at 10:03:09AM +0100, Stefan Richter wrote:
> On 15 Jan, Jens Axboe wrote:
> > On Fri, Jan 15 2010, Stefan Richter wrote:
> >> The sg driver's open method takes a reference to the underlying SCSI
> >> device representation of the mid layer.  Among else, this step increases
> >> the module use count of the respective low-level driver
> ...
> >> In short, it is normal, expected, and necessary what you are seeing.
> > 
> > Hmm... Unless I'm reading Stephens email incorrectly, he's holding the
> > device open, removing it, closing the device, and then attempting to
> > remove the host driver. So at the point that he wants to rmmod the
> > module, there is indeed no references to it anymore.
> > 
> > It looks like a bug.
> 
> Oh, right, I missed that the device file was indeed closed ( = the
> seemingly last user of it exited) before rmmod was attempted.
> 
> I.e. remove-single-device while an sg file is open leaves a dangling
> reference, while remove-single-device while an sd file is open does
> not...
> -- 
> Stefan Richter
> -=====-==-=- ---= -====
> http://arcgraph.de/sr/
> 

I've since tried this on a newer kernel, 2.6.33rc4 (previously I 
was using a 2.6.27 kernel). 

With the 2.6.33rc4 kernel, so far the problem hasn't appeared. 

Thanks, and sorry I didn't try the newer kernel first.

-- steve