Re: [PATCH v3] futex: Remove requirement for lock_page in

[Thomas Gleixner]

On Wed, 20 Jan 2016, Davidlohr Bueso wrote:
> On Tue, 19 Jan 2016, Bueso wrote:
> > +
> > +		/* Should be impossible but lets be paranoid for now */
> > +		BUG_ON(inode->i_mapping != mapping);
> 
> Hmm, do we want to transform this into an if and do rcu unlock and then just
> call BUG()? I't doesn't matter at this point _anyway_, but it would be the
> right
> thing to do, no?

The better solution is to err out gracefully.

    	   if (WARN_ON_ONCE(inode->i_mapping != mapping) {
	      	   err = -EFAULT;
		   rcu_read_unlock();
		   goto out;
    	   }

Hmm?

Thanks,

	tglx