[PATCH hmm 5/8] mm/hmm: add missing call to hmm_range_need_fault() before returning EFAULT

[Christoph Hellwig]

On Wed, Mar 11, 2020 at 03:35:03PM -0300, Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg at mellanox.com>
> 
> All return paths that do EFAULT must call hmm_range_need_fault() to
> determine if the user requires this page to be valid.
> 
> If the page cannot be made valid if the user later requires it, due to vma
> flags in this case, then the return should be HMM_PFN_ERROR.
> 
> Fixes: a3e0d41c2b1f ("mm/hmm: improve driver API to work and wait over a range")
> Signed-off-by: Jason Gunthorpe <jgg at mellanox.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch at lst.de>