I already said it in another thread, but IMO Linus's comments are best seen as a legal positioning to avoid Oracle's thugs going after him for copying ZFS features or for developing code that he knows will be mingled with CDDL.

Having said that, I don't understand why ZoL can't just declare itself as GPL to the kernel and get access to whatever symbols it wants. I thought the only legal teeth that mechanism had is for showing willfull infringement. But ZoL releases source and already bridges the GPL and CDDL by strictly delaying their mixture until runtime, so I would think additional GPL objections by the kernel would be moot.