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