Re: [PATCH][RESEND] scsi_sysfs: add 'is_bin_visible' callback

[Christoph Hellwig <hch@lst.de>]

On Wed, Mar 02, 2016 at 03:33:14PM +0800, Hannes Reinecke wrote:
> >> +	rcu_read_lock();
> >> +	if (attr == &dev_attr_vpd_pg80 &&
> >> +	    !rcu_dereference(sdev->vpd_pg80)) {
> >> +		rcu_read_unlock();
> >> +		return 0;
> >> +	}
> >> +	if (attr == &dev_attr_vpd_pg83 &&
> >> +	    !rcu_dereference(sdev->vpd_pg83)) {
> >> +		rcu_read_unlock();
> >> +		return 0;
> >> +	}
> >> +	rcu_read_unlock();
> > 
> > We are only checking the pointers for being non-zero.  No need for the
> > rcu_read_lock() or rcu_dereference() here.
> > 
> Better to be same than sorry; some overly clever code analysis tool
> might trip over it otherwise.

It shouldn't.  There is no dereference going on here.

> 
> > Otherwise this looks fine to me.
> 
> Reviewed-by: ?

Only without the cargo culted rcu magic.