Re: [PATCH 11/25] memremap: lift the devmap_enable manipulation into devm_memremap_pages

[Christoph Hellwig]

On Wed, Jun 26, 2019 at 12:04:46PM -0700, Ira Weiny wrote:
> > +static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap)
> > +{
> > +	if (!pgmap->ops->page_free) {
> 
> NIT: later on you add the check for pgmap->ops...  it should probably be here.
> 
> But not sure that bisection will be an issue here.

At this point we do not allow a NULL ops pointer.  That only becomes
a valid option one the internal refcount is added.  Until then a NULL
->ops pointer leads to an error return from devm_memremap_pages.