Re: [PATCH 1/3] scsi: serialize ->rescan against ->remove

[Fam Zheng <famz@redhat.com>]

On Fri, 01/30 00:11, Paolo Bonzini wrote:
> 
> 
> On 29/01/2015 00:00, Christoph Hellwig wrote:
> > Lock the device embedded in the scsi_device to protect against
> > concurrent calls to ->remove.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> I wonder if this makes this problem: https://lkml.org/lkml/2015/1/5/9 go
> away.

A quick test says yes.

Fam

> 
> Paolo
> 
> > ---
> >  drivers/scsi/scsi_scan.c | 7 +++----
> >  1 file changed, 3 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> > index 983aed1..523faee 100644
> > --- a/drivers/scsi/scsi_scan.c
> > +++ b/drivers/scsi/scsi_scan.c
> > @@ -1593,16 +1593,15 @@ EXPORT_SYMBOL(scsi_add_device);
> >  
> >  void scsi_rescan_device(struct device *dev)
> >  {
> > -	if (!dev->driver)
> > -		return;
> > -
> > -	if (try_module_get(dev->driver->owner)) {
> > +	device_lock(dev);
> > +	if (dev->driver && try_module_get(dev->driver->owner)) {
> >  		struct scsi_driver *drv = to_scsi_driver(dev->driver);
> >  
> >  		if (drv->rescan)
> >  			drv->rescan(dev);
> >  		module_put(dev->driver->owner);
> >  	}
> > +	device_unlock(dev);
> >  }
> >  EXPORT_SYMBOL(scsi_rescan_device);
> >  
> > 
> --
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