Re: [PATCH 04/14] memstick: core: fix device_register() errorhandling
From: Vasiliy Kulikov
Date: Thu Sep 23 2010 - 08:10:45 EST
On Wed, Sep 22, 2010 at 08:50 -0700, Greg KH wrote:
> On Wed, Sep 22, 2010 at 10:53:21AM +0200, Kay Sievers wrote:
> > On Wed, Sep 22, 2010 at 00:49, Greg KH <greg@xxxxxxxxx> wrote:
> >
> > > int device_register(struct device *dev)
> > > {
> > > + int retval;
> > > +
> > > device_initialize(dev);
> > > - return device_add(dev);
> > > + retval = device_add(dev);
> > > + if (retval)
> > > + put_device(dev);
> > > + return retval;
> > > }
> >
> > > Kay, what am I missing here, why can't we just do this? Hm, the
> > > side-affect might be that if device_register() fails, NO ONE had better
> > > touch that device again, as it might have just been freed from the
> > > system. I wonder if that will cause problems...
> >
> > That looks right, besides that there might be callers already doing
> > this. Which needs to be checked.
>
> Yes, it would be. I'll go through the tree.
As I see with this in-device_register patch we should check for 2 things:
1) nobody should call put_device() because of failed device_register().
2) dev has to be already got, other words its ref counter should not be zero.
Correct?
--
Vasiliy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/