[PATCH] NVMe: Create discard zero quirk white list

[Christoph Hellwig]

On Sat, Mar 05, 2016 at 05:39:49PM -0500, Matthew Wilcox wrote:
> > Meh, indeed:
> > 
> > "If a read occurs to a deallocated range, the controller shall return
> > all zeros, all ones, or the last data written to the associated LBA."
> > 
> > time to write a TP for a bit on the identify page..
> 
> Since we have a WRITE ZEROES command, do we need this?

WRITE ZEROES has no way to request deallocating blocks.  It's the moral
equivalent of a WRITE SAME without the unmap bit of all zeroes.