Re: [PATCH v7 07/24] IB/umem: use get_user_pages_fast() to pin DMA pages

[Jason Gunthorpe]

On Sun, Nov 24, 2019 at 04:05:16PM -0800, John Hubbard wrote:
 
> I looked into this, and I believe that the problem is in gup.c. There appears to
> have been an oversight, in commit 817be129e6f2 ("mm: validate get_user_pages_fast
> flags"), in filtering out FOLL_FORCE. There is nothing in the _fast() implementation
> that requires that we avoid writing to the pages.

I think it is too late to be doing these kinds of changes, I will
revert the patch and this will miss this merge window.

Jason